Publish ExoPlayer's support for RTSP.

Allow ExoPlayer to open URIs starting with rtsp://

PiperOrigin-RevId: 370653248

RELEASENOTES.md

@@ -132,6 +132,8 @@
         `DashMediaSource.Factory`.
     *   We don't currently support using platform extractors with
         SmoothStreaming.
+*   RTSP
+    *   Release the initial version of ExoPlayer's RTSP support.
 
 ### 2.13.3 (2021-04-14)
 

core_settings.gradle

@@ -27,6 +27,7 @@ include modulePrefix + 'library-core'
 include modulePrefix + 'library-dash'
 include modulePrefix + 'library-extractor'
 include modulePrefix + 'library-hls'
+include modulePrefix + 'library-rtsp'
 include modulePrefix + 'library-smoothstreaming'
 include modulePrefix + 'library-transformer'
 include modulePrefix + 'library-ui'
@@ -55,6 +56,7 @@ project(modulePrefix + 'library-core').projectDir = new File(rootDir, 'library/c
 project(modulePrefix + 'library-dash').projectDir = new File(rootDir, 'library/dash')
 project(modulePrefix + 'library-extractor').projectDir = new File(rootDir, 'library/extractor')
 project(modulePrefix + 'library-hls').projectDir = new File(rootDir, 'library/hls')
+project(modulePrefix + 'library-rtsp').projectDir = new File(rootDir, 'library/rtsp')
 project(modulePrefix + 'library-smoothstreaming').projectDir = new File(rootDir, 'library/smoothstreaming')
 project(modulePrefix + 'library-transformer').projectDir = new File(rootDir, 'library/transformer')
 project(modulePrefix + 'library-ui').projectDir = new File(rootDir, 'library/ui')

library/common/src/main/java/com/google/android/exoplayer2/C.java

@@ -607,11 +607,11 @@ public final class C {
 
   /**
    * Represents a streaming or other media type. One of {@link #TYPE_DASH}, {@link #TYPE_SS}, {@link
-   * #TYPE_HLS} or {@link #TYPE_OTHER}.
+   * #TYPE_HLS}, {@link #TYPE_RTSP} or {@link #TYPE_OTHER}.
    */
   @Documented
   @Retention(RetentionPolicy.SOURCE)
-  @IntDef({TYPE_DASH, TYPE_SS, TYPE_HLS, TYPE_OTHER})
+  @IntDef({TYPE_DASH, TYPE_SS, TYPE_HLS, TYPE_RTSP, TYPE_OTHER})
   public @interface ContentType {}
   /**
    * Value returned by {@link Util#inferContentType(String)} for DASH manifests.
@@ -625,11 +625,13 @@ public final class C {
    * Value returned by {@link Util#inferContentType(String)} for HLS manifests.
    */
   public static final int TYPE_HLS = 2;
+  /** Value returned by {@link Util#inferContentType(String)} for RTSP. */
+  public static final int TYPE_RTSP = 3;
   /**
    * Value returned by {@link Util#inferContentType(String)} for files other than DASH, HLS or
-   * Smooth Streaming manifests.
+   * Smooth Streaming manifests, or RTSP URIs.
    */
-  public static final int TYPE_OTHER = 3;
+  public static final int TYPE_OTHER = 4;
 
   /**
    * A return value for methods where the end of an input was encountered.

library/common/src/main/java/com/google/android/exoplayer2/util/MimeTypes.java

@@ -112,6 +112,7 @@ public final class MimeTypes {
   public static final String APPLICATION_EXIF = BASE_TYPE_APPLICATION + "/x-exif";
   public static final String APPLICATION_ICY = BASE_TYPE_APPLICATION + "/x-icy";
   public static final String APPLICATION_AIT = BASE_TYPE_APPLICATION + "/vnd.dvb.ait";
+  public static final String APPLICATION_RTSP = BASE_TYPE_APPLICATION + "/x-rtsp";
 
   public static final String IMAGE_JPEG = BASE_TYPE_IMAGE + "/jpeg";
 

library/common/src/main/java/com/google/android/exoplayer2/util/Util.java

@@ -1800,6 +1800,11 @@ public final class Util {
    */
   @ContentType
   public static int inferContentType(Uri uri) {
+    @Nullable String scheme = uri.getScheme();
+    if (scheme != null && Ascii.equalsIgnoreCase("rtsp", scheme)) {
+      return C.TYPE_RTSP;
+    }
+
     @Nullable String path = uri.getPath();
     return path == null ? C.TYPE_OTHER : inferContentType(path);
   }
@@ -1852,6 +1857,8 @@ public final class Util {
         return C.TYPE_HLS;
       case MimeTypes.APPLICATION_SS:
         return C.TYPE_SS;
+      case MimeTypes.APPLICATION_RTSP:
+        return C.TYPE_RTSP;
       default:
         return C.TYPE_OTHER;
     }

library/core/proguard-rules.txt

@@ -64,3 +64,7 @@
 -keepclasseswithmembers class com.google.android.exoplayer2.source.smoothstreaming.SsMediaSource$Factory {
   <init>(com.google.android.exoplayer2.upstream.DataSource$Factory);
 }
+-dontnote com.google.android.exoplayer2.source.rtsp.RtspMediaSource$Factory
+-keepclasseswithmembers class com.google.android.exoplayer2.source.rtsp.RtspMediaSource$Factory {
+  <init>();
+}

library/core/src/main/java/com/google/android/exoplayer2/source/DefaultMediaSourceFactory.java

@@ -468,6 +468,14 @@ public final class DefaultMediaSourceFactory implements MediaSourceFactory {
     } catch (Exception e) {
       // Expected if the app was built without the hls module.
     }
+    try {
+      Class<? extends MediaSourceFactory> factoryClazz =
+          Class.forName("com.google.android.exoplayer2.source.rtsp.RtspMediaSource$Factory")
+              .asSubclass(MediaSourceFactory.class);
+      factories.put(C.TYPE_RTSP, factoryClazz.getConstructor().newInstance());
+    } catch (Exception e) {
+      // Expected if the app was built without the RTSP module.
+    }
     // LINT.ThenChange(../../../../../../../../proguard-rules.txt)
     factories.put(
         C.TYPE_OTHER, new ProgressiveMediaSource.Factory(dataSourceFactory, extractorsFactory));

library/rtsp/build.gradle

@@ -0,0 +1,49 @@
+// Copyright 2020 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+apply from: "$gradle.ext.exoplayerSettingsDir/common_library_config.gradle"
+
+android {
+    buildTypes {
+        debug {
+            testCoverageEnabled = true
+        }
+    }
+
+    sourceSets.test.assets.srcDir '../../testdata/src/test/assets/'
+}
+
+dependencies {
+    implementation 'androidx.annotation:annotation:' + androidxAnnotationVersion
+    compileOnly 'org.checkerframework:checker-qual:' + checkerframeworkVersion
+    compileOnly 'org.checkerframework:checker-compat-qual:' + checkerframeworkCompatVersion
+    compileOnly 'org.jetbrains.kotlin:kotlin-annotations-jvm:' + kotlinAnnotationsVersion
+    implementation project(modulePrefix + 'library-core')
+    testImplementation project(modulePrefix + 'robolectricutils')
+    testImplementation project(modulePrefix + 'testutils')
+    testImplementation project(modulePrefix + 'testdata')
+    testImplementation 'org.checkerframework:checker-qual:' + checkerframeworkVersion
+    testImplementation 'org.checkerframework:checker-compat-qual:' + checkerframeworkCompatVersion
+    testImplementation 'org.robolectric:robolectric:' + robolectricVersion
+}
+
+ext {
+    javadocTitle = 'RTSP module'
+}
+apply from: '../../javadoc_library.gradle'
+
+ext {
+    releaseArtifact = 'exoplayer-rtsp'
+    releaseDescription = 'The ExoPlayer library RTSP module.'
+}
+apply from: '../../publish.gradle'

library/rtsp/src/main/AndroidManifest.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright 2020 The Android Open Source Project
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+
+<manifest package="com.google.android.exoplayer2.source.rtsp"/>

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/RtspClient.java

@@ -0,0 +1,550 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.source.rtsp;
+
+import static com.google.android.exoplayer2.source.rtsp.message.RtspMessageChannel.DEFAULT_RTSP_PORT;
+import static com.google.android.exoplayer2.source.rtsp.message.RtspRequest.METHOD_ANNOUNCE;
+import static com.google.android.exoplayer2.source.rtsp.message.RtspRequest.METHOD_DESCRIBE;
+import static com.google.android.exoplayer2.source.rtsp.message.RtspRequest.METHOD_GET_PARAMETER;
+import static com.google.android.exoplayer2.source.rtsp.message.RtspRequest.METHOD_OPTIONS;
+import static com.google.android.exoplayer2.source.rtsp.message.RtspRequest.METHOD_PAUSE;
+import static com.google.android.exoplayer2.source.rtsp.message.RtspRequest.METHOD_PLAY;
+import static com.google.android.exoplayer2.source.rtsp.message.RtspRequest.METHOD_PLAY_NOTIFY;
+import static com.google.android.exoplayer2.source.rtsp.message.RtspRequest.METHOD_RECORD;
+import static com.google.android.exoplayer2.source.rtsp.message.RtspRequest.METHOD_REDIRECT;
+import static com.google.android.exoplayer2.source.rtsp.message.RtspRequest.METHOD_SETUP;
+import static com.google.android.exoplayer2.source.rtsp.message.RtspRequest.METHOD_SET_PARAMETER;
+import static com.google.android.exoplayer2.source.rtsp.message.RtspRequest.METHOD_TEARDOWN;
+import static com.google.android.exoplayer2.source.rtsp.message.RtspRequest.METHOD_UNSET;
+import static com.google.android.exoplayer2.util.Assertions.checkArgument;
+import static com.google.android.exoplayer2.util.Assertions.checkNotNull;
+import static com.google.android.exoplayer2.util.Assertions.checkState;
+import static com.google.common.base.Strings.nullToEmpty;
+
+import android.net.Uri;
+import android.os.Handler;
+import android.util.SparseArray;
+import androidx.annotation.Nullable;
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.ParserException;
+import com.google.android.exoplayer2.source.rtsp.RtspMediaPeriod.RtpLoadInfo;
+import com.google.android.exoplayer2.source.rtsp.RtspMediaSource.RtspPlaybackException;
+import com.google.android.exoplayer2.source.rtsp.message.RtspDescribeResponse;
+import com.google.android.exoplayer2.source.rtsp.message.RtspHeaders;
+import com.google.android.exoplayer2.source.rtsp.message.RtspMessageChannel;
+import com.google.android.exoplayer2.source.rtsp.message.RtspMessageUtil;
+import com.google.android.exoplayer2.source.rtsp.message.RtspMessageUtil.RtspSessionHeader;
+import com.google.android.exoplayer2.source.rtsp.message.RtspOptionsResponse;
+import com.google.android.exoplayer2.source.rtsp.message.RtspPlayResponse;
+import com.google.android.exoplayer2.source.rtsp.message.RtspRequest;
+import com.google.android.exoplayer2.source.rtsp.message.RtspResponse;
+import com.google.android.exoplayer2.source.rtsp.message.RtspSetupResponse;
+import com.google.android.exoplayer2.source.rtsp.rtp.RtpPayloadFormat;
+import com.google.android.exoplayer2.source.rtsp.sdp.MediaDescription;
+import com.google.android.exoplayer2.source.rtsp.sdp.SessionDescription;
+import com.google.android.exoplayer2.source.rtsp.sdp.SessionDescriptionParser;
+import com.google.android.exoplayer2.util.Util;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+import java.io.Closeable;
+import java.io.IOException;
+import java.net.Socket;
+import java.util.ArrayDeque;
+import java.util.List;
+import java.util.Map;
+import javax.net.SocketFactory;
+import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
+
+/** The RTSP client. */
+/* package */ final class RtspClient implements Closeable {
+
+  private static final long DEFAULT_RTSP_KEEP_ALIVE_INTERVAL_MS = 30_000;
+
+  /** A listener for session information update. */
+  public interface SessionInfoListener {
+    /** Called when the session information is available. */
+    void onSessionTimelineUpdated(RtspSessionTiming timing, ImmutableList<RtspMediaTrack> tracks);
+    /**
+     * Called when failed to get session information from the RTSP server, or when error happened
+     * during updating the session timeline.
+     */
+    void onSessionTimelineRequestFailed(String message, @Nullable Throwable cause);
+  }
+
+  /** A listener for playback events. */
+  public interface PlaybackEventListener {
+    /** Called when setup is completed and playback can start. */
+    void onRtspSetupCompleted();
+
+    /**
+     * Called when a PLAY request is acknowledged by the server and playback can start.
+     *
+     * @param startPositionUs The server-supplied start position in microseconds.
+     * @param trackTimingList The list of {@link RtspTrackTiming} for the playing tracks.
+     */
+    void onPlaybackStarted(long startPositionUs, ImmutableList<RtspTrackTiming> trackTimingList);
+
+    /** Called when errors are encountered during playback. */
+    void onPlaybackError(RtspPlaybackException error);
+  }
+
+  private final SessionInfoListener sessionInfoListener;
+  private final Uri uri;
+  @Nullable private final String userAgent;
+  private final RtspMessageChannel messageChannel;
+  private final ArrayDeque<RtpLoadInfo> pendingSetupRtpLoadInfos;
+  // TODO(b/172331505) Add a timeout monitor for pending requests.
+  private final SparseArray<RtspRequest> pendingRequests;
+  private final MessageSender messageSender;
+
+  private @MonotonicNonNull PlaybackEventListener playbackEventListener;
+  private @MonotonicNonNull String sessionId;
+  @Nullable private KeepAliveMonitor keepAliveMonitor;
+  private boolean hasUpdatedTimelineAndTracks;
+  private long pendingSeekPositionUs;
+
+  /**
+   * Creates a new instance.
+   *
+   * <p>The constructor must be called on the playback thread. The thread is also where {@link
+   * SessionInfoListener} and {@link PlaybackEventListener} events are sent. User must {@link
+   * #start} the client, and {@link #close} it when done.
+   *
+   * <p>Note: all method invocations must be made from the playback thread.
+   *
+   * @param sessionInfoListener The {@link SessionInfoListener}.
+   * @param userAgent The user agent that will be used if needed, or {@code null} for the fallback
+   *     to use the default user agent of the underlying platform.
+   * @param uri The RTSP playback URI.
+   */
+  public RtspClient(SessionInfoListener sessionInfoListener, @Nullable String userAgent, Uri uri) {
+    this.sessionInfoListener = sessionInfoListener;
+    this.uri = RtspMessageUtil.removeUserInfo(uri);
+    this.userAgent = userAgent;
+    messageChannel = new RtspMessageChannel(new MessageListener());
+    pendingSetupRtpLoadInfos = new ArrayDeque<>();
+    pendingRequests = new SparseArray<>();
+    messageSender = new MessageSender();
+    pendingSeekPositionUs = C.TIME_UNSET;
+  }
+
+  /**
+   * Starts the client and sends an OPTIONS request.
+   *
+   * <p>Calls {@link #close()} if {@link IOException} is thrown when opening a connection to the
+   * supplied {@link Uri}.
+   *
+   * @throws IOException When failed to open a connection to the supplied {@link Uri}.
+   */
+  public void start() throws IOException {
+    checkArgument(uri.getHost() != null);
+    int rtspPort = uri.getPort() > 0 ? uri.getPort() : DEFAULT_RTSP_PORT;
+    Socket socket = SocketFactory.getDefault().createSocket(checkNotNull(uri.getHost()), rtspPort);
+    try {
+      messageChannel.openSocket(socket);
+    } catch (IOException e) {
+      Util.closeQuietly(messageChannel);
+      throw e;
+    }
+    messageSender.sendOptionsRequest(uri, sessionId);
+  }
+
+  /** Sets the {@link PlaybackEventListener} to receive playback events. */
+  public void setPlaybackEventListener(PlaybackEventListener playbackEventListener) {
+    this.playbackEventListener = playbackEventListener;
+  }
+
+  /**
+   * Triggers RTSP SETUP requests after track selection.
+   *
+   * <p>A {@link PlaybackEventListener} must be set via {@link #setPlaybackEventListener} before
+   * calling this method. All selected tracks (represented by {@link RtpLoadInfo}) must have valid
+   * transport.
+   *
+   * @param loadInfos A list of selected tracks represented by {@link RtpLoadInfo}.
+   */
+  public void setupSelectedTracks(List<RtpLoadInfo> loadInfos) {
+    pendingSetupRtpLoadInfos.addAll(loadInfos);
+    continueSetupRtspTrack();
+  }
+
+  /**
+   * Starts RTSP playback by sending RTSP PLAY request.
+   *
+   * @param offsetMs The playback offset in milliseconds, with respect to the stream start position.
+   */
+  public void startPlayback(long offsetMs) {
+    messageSender.sendPlayRequest(uri, offsetMs, checkNotNull(sessionId));
+  }
+
+  /**
+   * Seeks to a specific time using RTSP.
+   *
+   * <p>Call this method only when in-buffer seek is not feasible. An RTSP PAUSE, and an RTSP PLAY
+   * request will be sent out to perform a seek on the server side.
+   *
+   * @param positionUs The seek time measured in microseconds.
+   */
+  public void seekToUs(long positionUs) {
+    messageSender.sendPauseRequest(uri, checkNotNull(sessionId));
+    pendingSeekPositionUs = positionUs;
+  }
+
+  @Override
+  public void close() throws IOException {
+    if (keepAliveMonitor != null) {
+      // Playback has started. We have to stop the periodic keep alive and send a TEARDOWN so that
+      // the RTSP server stops sending RTP packets and frees up resources.
+      keepAliveMonitor.close();
+      keepAliveMonitor = null;
+      messageSender.sendTeardownRequest(uri, checkNotNull(sessionId));
+    }
+    messageChannel.close();
+  }
+
+  private void continueSetupRtspTrack() {
+    @Nullable RtpLoadInfo loadInfo = pendingSetupRtpLoadInfos.pollFirst();
+    if (loadInfo == null) {
+      checkNotNull(playbackEventListener).onRtspSetupCompleted();
+      return;
+    }
+    messageSender.sendSetupRequest(loadInfo.getTrackUri(), loadInfo.getTransport(), sessionId);
+  }
+
+  /**
+   * Returns whether the RTSP server supports the DESCRIBE method.
+   *
+   * <p>The DESCRIBE method is marked "recommended to implement" in RFC2326 Section 10. We assume
+   * the server supports DESCRIBE, if the OPTIONS response does not include a PUBLIC header.
+   *
+   * @param serverSupportedMethods A list of RTSP methods (as defined in RFC2326 Section 10, encoded
+   *     as {@link RtspRequest.Method}) that are supported by the RTSP server.
+   */
+  private static boolean serverSupportsDescribe(List<Integer> serverSupportedMethods) {
+    return serverSupportedMethods.isEmpty() || serverSupportedMethods.contains(METHOD_DESCRIBE);
+  }
+
+  /**
+   * Gets the included {@link RtspMediaTrack RtspMediaTracks} from a {@link SessionDescription}.
+   *
+   * @param sessionDescription The {@link SessionDescription}.
+   * @param uri The RTSP playback URI.
+   */
+  private static ImmutableList<RtspMediaTrack> buildTrackList(
+      SessionDescription sessionDescription, Uri uri) {
+    ImmutableList.Builder<RtspMediaTrack> trackListBuilder = new ImmutableList.Builder<>();
+    for (int i = 0; i < sessionDescription.mediaDescriptionList.size(); i++) {
+      MediaDescription mediaDescription = sessionDescription.mediaDescriptionList.get(i);
+      // Includes tracks with supported formats only.
+      if (RtpPayloadFormat.isFormatSupported(mediaDescription)) {
+        trackListBuilder.add(new RtspMediaTrack(mediaDescription, uri));
+      }
+    }
+    return trackListBuilder.build();
+  }
+
+  private final class MessageSender {
+
+    private int cSeq;
+
+    public void sendOptionsRequest(Uri uri, @Nullable String sessionId) {
+      sendRequest(
+          getRequestWithCommonHeaders(
+              METHOD_OPTIONS, sessionId, /* additionalHeaders= */ ImmutableMap.of(), uri));
+    }
+
+    public void sendDescribeRequest(Uri uri, @Nullable String sessionId) {
+      sendRequest(
+          getRequestWithCommonHeaders(
+              METHOD_DESCRIBE, sessionId, /* additionalHeaders= */ ImmutableMap.of(), uri));
+    }
+
+    public void sendSetupRequest(Uri trackUri, String transport, @Nullable String sessionId) {
+      sendRequest(
+          getRequestWithCommonHeaders(
+              METHOD_SETUP,
+              sessionId,
+              /* additionalHeaders= */ ImmutableMap.of(RtspHeaders.TRANSPORT, transport),
+              trackUri));
+    }
+
+    public void sendPlayRequest(Uri uri, long offsetMs, String sessionId) {
+      sendRequest(
+          getRequestWithCommonHeaders(
+              METHOD_PLAY,
+              sessionId,
+              /* additionalHeaders= */ ImmutableMap.of(
+                  RtspHeaders.RANGE, RtspSessionTiming.getOffsetStartTimeTiming(offsetMs)),
+              uri));
+    }
+
+    public void sendTeardownRequest(Uri uri, String sessionId) {
+      sendRequest(
+          getRequestWithCommonHeaders(
+              METHOD_TEARDOWN, sessionId, /* additionalHeaders= */ ImmutableMap.of(), uri));
+    }
+
+    public void sendPauseRequest(Uri uri, String sessionId) {
+      sendRequest(
+          getRequestWithCommonHeaders(
+              METHOD_PAUSE, sessionId, /* additionalHeaders= */ ImmutableMap.of(), uri));
+    }
+
+    private RtspRequest getRequestWithCommonHeaders(
+        @RtspRequest.Method int method,
+        @Nullable String sessionId,
+        Map<String, String> additionalHeaders,
+        Uri uri) {
+      RtspHeaders.Builder headersBuilder = new RtspHeaders.Builder();
+      headersBuilder.add(RtspHeaders.CSEQ, String.valueOf(cSeq++));
+
+      if (userAgent != null) {
+        headersBuilder.add(RtspHeaders.USER_AGENT, userAgent);
+      }
+
+      if (sessionId != null) {
+        headersBuilder.add(RtspHeaders.SESSION, sessionId);
+      }
+
+      headersBuilder.addAll(additionalHeaders);
+      return new RtspRequest(uri, method, headersBuilder.build(), /* messageBody= */ "");
+    }
+
+    private void sendRequest(RtspRequest request) {
+      int cSeq = Integer.parseInt(checkNotNull(request.headers.get(RtspHeaders.CSEQ)));
+      checkState(pendingRequests.get(cSeq) == null);
+      pendingRequests.append(cSeq, request);
+      messageChannel.send(RtspMessageUtil.serializeRequest(request));
+    }
+  }
+
+  private final class MessageListener implements RtspMessageChannel.MessageListener {
+
+    @Override
+    public void onRtspMessageReceived(List<String> message) {
+      RtspResponse response = RtspMessageUtil.parseResponse(message);
+
+      int cSeq = Integer.parseInt(checkNotNull(response.headers.get(RtspHeaders.CSEQ)));
+
+      @Nullable RtspRequest matchingRequest = pendingRequests.get(cSeq);
+      if (matchingRequest == null) {
+        return;
+      } else {
+        pendingRequests.remove(cSeq);
+      }
+
+      @RtspRequest.Method int requestMethod = matchingRequest.method;
+
+      if (response.status != 200) {
+        dispatchRtspError(
+            new RtspPlaybackException(
+                RtspMessageUtil.toMethodString(requestMethod) + " " + response.status));
+        return;
+      }
+
+      try {
+        switch (requestMethod) {
+          case METHOD_OPTIONS:
+            onOptionsResponseReceived(
+                new RtspOptionsResponse(
+                    response.status,
+                    RtspMessageUtil.parsePublicHeader(response.headers.get(RtspHeaders.PUBLIC))));
+            break;
+
+          case METHOD_DESCRIBE:
+            onDescribeResponseReceived(
+                new RtspDescribeResponse(
+                    response.status, SessionDescriptionParser.parse(response.messageBody)));
+            break;
+
+          case METHOD_SETUP:
+            @Nullable String sessionHeaderString = response.headers.get(RtspHeaders.SESSION);
+            @Nullable String transportHeaderString = response.headers.get(RtspHeaders.TRANSPORT);
+            if (sessionHeaderString == null || transportHeaderString == null) {
+              throw new ParserException();
+            }
+
+            RtspSessionHeader sessionHeader =
+                RtspMessageUtil.parseSessionHeader(sessionHeaderString);
+            onSetupResponseReceived(
+                new RtspSetupResponse(response.status, sessionHeader, transportHeaderString));
+            break;
+
+          case METHOD_PLAY:
+            // Range header is optional for a PLAY response (RFC2326 Section 12).
+            @Nullable String startTimingString = response.headers.get(RtspHeaders.RANGE);
+            RtspSessionTiming timing =
+                startTimingString == null
+                    ? RtspSessionTiming.DEFAULT
+                    : RtspSessionTiming.parseTiming(startTimingString);
+            @Nullable String rtpInfoString = response.headers.get(RtspHeaders.RTP_INFO);
+            ImmutableList<RtspTrackTiming> trackTimingList =
+                rtpInfoString == null
+                    ? ImmutableList.of()
+                    : RtspTrackTiming.parseTrackTiming(rtpInfoString);
+            onPlayResponseReceived(new RtspPlayResponse(response.status, timing, trackTimingList));
+            break;
+
+          case METHOD_GET_PARAMETER:
+            onGetParameterResponseReceived(response);
+            break;
+
+          case METHOD_TEARDOWN:
+            onTeardownResponseReceived(response);
+            break;
+
+          case METHOD_PAUSE:
+            onPauseResponseReceived(response);
+            break;
+
+          case METHOD_PLAY_NOTIFY:
+          case METHOD_RECORD:
+          case METHOD_REDIRECT:
+          case METHOD_ANNOUNCE:
+          case METHOD_SET_PARAMETER:
+            onUnsupportedResponseReceived(response);
+            break;
+          case METHOD_UNSET:
+          default:
+            throw new IllegalStateException();
+        }
+      } catch (ParserException e) {
+        dispatchRtspError(new RtspPlaybackException(e));
+      }
+    }
+
+    // Response handlers must only be called only on 200 (OK) responses.
+
+    public void onOptionsResponseReceived(RtspOptionsResponse response) {
+      if (keepAliveMonitor != null) {
+        // Ignores the OPTIONS requests that are sent to keep RTSP connection alive.
+        return;
+      }
+
+      if (serverSupportsDescribe(response.supportedMethods)) {
+        messageSender.sendDescribeRequest(uri, sessionId);
+      } else {
+        sessionInfoListener.onSessionTimelineRequestFailed(
+            "DESCRIBE not supported.", /* cause= */ null);
+      }
+    }
+
+    public void onDescribeResponseReceived(RtspDescribeResponse response) {
+      String sessionRangeAttributeString =
+          checkNotNull(response.sessionDescription.attributes.get(SessionDescription.ATTR_RANGE));
+
+      try {
+        sessionInfoListener.onSessionTimelineUpdated(
+            RtspSessionTiming.parseTiming(sessionRangeAttributeString),
+            buildTrackList(response.sessionDescription, uri));
+        hasUpdatedTimelineAndTracks = true;
+      } catch (ParserException e) {
+        sessionInfoListener.onSessionTimelineRequestFailed("SDP format error.", /* cause= */ e);
+      }
+    }
+
+    public void onSetupResponseReceived(RtspSetupResponse response) {
+      sessionId = response.sessionHeader.sessionId;
+      continueSetupRtspTrack();
+    }
+
+    public void onPlayResponseReceived(RtspPlayResponse response) {
+      if (keepAliveMonitor == null) {
+        keepAliveMonitor = new KeepAliveMonitor(DEFAULT_RTSP_KEEP_ALIVE_INTERVAL_MS);
+        keepAliveMonitor.start();
+      }
+
+      checkNotNull(playbackEventListener)
+          .onPlaybackStarted(
+              C.msToUs(response.sessionTiming.startTimeMs), response.trackTimingList);
+      pendingSeekPositionUs = C.TIME_UNSET;
+    }
+
+    public void onPauseResponseReceived(RtspResponse response) {
+      if (pendingSeekPositionUs != C.TIME_UNSET) {
+        startPlayback(C.usToMs(pendingSeekPositionUs));
+      }
+    }
+
+    public void onGetParameterResponseReceived(RtspResponse response) {
+      // Do nothing.
+    }
+
+    public void onTeardownResponseReceived(RtspResponse response) {
+      // Do nothing.
+    }
+
+    public void onUnsupportedResponseReceived(RtspResponse response) {
+      // Do nothing.
+    }
+
+    private void dispatchRtspError(Throwable error) {
+      RtspPlaybackException playbackException =
+          error instanceof RtspPlaybackException
+              ? (RtspPlaybackException) error
+              : new RtspPlaybackException(error);
+
+      if (hasUpdatedTimelineAndTracks) {
+        // Playback event listener must be non-null after timeline has been updated.
+        checkNotNull(playbackEventListener).onPlaybackError(playbackException);
+      } else {
+        sessionInfoListener.onSessionTimelineRequestFailed(nullToEmpty(error.getMessage()), error);
+      }
+    }
+  }
+
+  /** Sends periodic OPTIONS requests to keep RTSP connection alive. */
+  private final class KeepAliveMonitor implements Runnable, Closeable {
+
+    private final Handler keepAliveHandler;
+    private final long intervalMs;
+    private boolean isStarted;
+
+    /**
+     * Creates a new instance.
+     *
+     * <p>Constructor must be invoked on the playback thread.
+     *
+     * @param intervalMs The time between consecutive RTSP keep-alive requests, in milliseconds.
+     */
+    public KeepAliveMonitor(long intervalMs) {
+      this.intervalMs = intervalMs;
+      keepAliveHandler = Util.createHandlerForCurrentLooper();
+    }
+
+    /** Starts Keep-alive. */
+    public void start() {
+      if (isStarted) {
+        return;
+      }
+
+      isStarted = true;
+      keepAliveHandler.postDelayed(this, intervalMs);
+    }
+
+    @Override
+    public void run() {
+      messageSender.sendOptionsRequest(uri, sessionId);
+      keepAliveHandler.postDelayed(this, intervalMs);
+    }
+
+    @Override
+    public void close() {
+      isStarted = false;
+      keepAliveHandler.removeCallbacks(this);
+    }
+  }
+}

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/RtspMediaPeriod.java

@@ -0,0 +1,658 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.android.exoplayer2.source.rtsp;
+
+import static com.google.android.exoplayer2.util.Assertions.checkNotNull;
+import static com.google.android.exoplayer2.util.Assertions.checkState;
+import static com.google.android.exoplayer2.util.Assertions.checkStateNotNull;
+import static java.lang.Math.min;
+
+import android.net.Uri;
+import android.os.Handler;
+import androidx.annotation.Nullable;
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.Format;
+import com.google.android.exoplayer2.FormatHolder;
+import com.google.android.exoplayer2.SeekParameters;
+import com.google.android.exoplayer2.decoder.DecoderInputBuffer;
+import com.google.android.exoplayer2.extractor.ExtractorOutput;
+import com.google.android.exoplayer2.extractor.SeekMap;
+import com.google.android.exoplayer2.extractor.TrackOutput;
+import com.google.android.exoplayer2.offline.StreamKey;
+import com.google.android.exoplayer2.source.MediaPeriod;
+import com.google.android.exoplayer2.source.SampleQueue;
+import com.google.android.exoplayer2.source.SampleQueue.UpstreamFormatChangedListener;
+import com.google.android.exoplayer2.source.SampleStream;
+import com.google.android.exoplayer2.source.SampleStream.ReadDataResult;
+import com.google.android.exoplayer2.source.SampleStream.ReadFlags;
+import com.google.android.exoplayer2.source.TrackGroup;
+import com.google.android.exoplayer2.source.TrackGroupArray;
+import com.google.android.exoplayer2.source.rtsp.RtspClient.PlaybackEventListener;
+import com.google.android.exoplayer2.source.rtsp.RtspMediaSource.RtspPlaybackException;
+import com.google.android.exoplayer2.source.rtsp.rtp.RtpDataLoadable;
+import com.google.android.exoplayer2.trackselection.ExoTrackSelection;
+import com.google.android.exoplayer2.trackselection.TrackSelection;
+import com.google.android.exoplayer2.upstream.Allocator;
+import com.google.android.exoplayer2.upstream.DataSource;
+import com.google.android.exoplayer2.upstream.Loader;
+import com.google.android.exoplayer2.upstream.Loader.Loadable;
+import com.google.android.exoplayer2.util.Util;
+import com.google.common.collect.ImmutableList;
+import java.io.IOException;
+import java.net.SocketTimeoutException;
+import java.util.ArrayList;
+import java.util.List;
+import org.checkerframework.checker.nullness.compatqual.NullableType;
+import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
+
+/** A {@link MediaPeriod} that loads an RTSP stream. */
+public final class RtspMediaPeriod implements MediaPeriod {
+
+  private static final String TAG = "RtspMediaPeriod";
+  private final Allocator allocator;
+  private final Handler handler;
+
+  private final InternalListener internalListener;
+  private final RtspClient rtspClient;
+  private final List<RtspLoaderWrapper> rtspLoaderWrappers;
+  private final List<RtpLoadInfo> selectedLoadInfos;
+
+  private @MonotonicNonNull Callback callback;
+  private @MonotonicNonNull ImmutableList<TrackGroup> trackGroups;
+  @Nullable private IOException preparationError;
+  @Nullable private RtspPlaybackException playbackException;
+
+  private long pendingSeekPositionUs;
+  private boolean loadingFinished;
+  private boolean released;
+  private boolean prepared;
+  private boolean trackSelected;
+
+  /**
+   * Creates an RTSP media period.
+   *
+   * @param allocator An {@link Allocator} from which to obtain media buffer allocations.
+   * @param rtspTracks A list of tracks in an RTSP playback session.
+   * @param rtspClient The {@link RtspClient} for the current RTSP playback.
+   */
+  public RtspMediaPeriod(
+      Allocator allocator, List<RtspMediaTrack> rtspTracks, RtspClient rtspClient) {
+    this.allocator = allocator;
+    handler = Util.createHandlerForCurrentLooper();
+
+    internalListener = new InternalListener();
+    rtspLoaderWrappers = new ArrayList<>(rtspTracks.size());
+    this.rtspClient = rtspClient;
+    this.rtspClient.setPlaybackEventListener(internalListener);
+
+    for (int i = 0; i < rtspTracks.size(); i++) {
+      RtspMediaTrack rtspMediaTrack = rtspTracks.get(i);
+      rtspLoaderWrappers.add(new RtspLoaderWrapper(rtspMediaTrack, /* trackId= */ i));
+    }
+    selectedLoadInfos = new ArrayList<>(rtspTracks.size());
+    pendingSeekPositionUs = C.TIME_UNSET;
+  }
+
+  /** Releases the {@link RtspMediaPeriod}. */
+  public void release() {
+    for (int i = 0; i < rtspLoaderWrappers.size(); i++) {
+      rtspLoaderWrappers.get(i).release();
+    }
+    released = true;
+  }
+
+  @Override
+  public void prepare(Callback callback, long positionUs) {
+    this.callback = callback;
+
+    for (int i = 0; i < rtspLoaderWrappers.size(); i++) {
+      rtspLoaderWrappers.get(i).startLoading();
+    }
+  }
+
+  @Override
+  public void maybeThrowPrepareError() throws IOException {
+    if (preparationError != null) {
+      throw preparationError;
+    }
+  }
+
+  @Override
+  public TrackGroupArray getTrackGroups() {
+    checkState(prepared);
+    return new TrackGroupArray(checkNotNull(trackGroups).toArray(new TrackGroup[0]));
+  }
+
+  @Override
+  public ImmutableList<StreamKey> getStreamKeys(List<ExoTrackSelection> trackSelections) {
+    return ImmutableList.of();
+  }
+
+  @Override
+  public long selectTracks(
+      @NullableType ExoTrackSelection[] selections,
+      boolean[] mayRetainStreamFlags,
+      @NullableType SampleStream[] streams,
+      boolean[] streamResetFlags,
+      long positionUs) {
+
+    // Deselect old tracks.
+    // Input array streams contains the streams selected in the previous track selection.
+    for (int i = 0; i < selections.length; i++) {
+      if (streams[i] != null && (selections[i] == null || !mayRetainStreamFlags[i])) {
+        streams[i] = null;
+      }
+    }
+
+    // Select new tracks.
+    selectedLoadInfos.clear();
+    for (int i = 0; i < selections.length; i++) {
+      TrackSelection selection = selections[i];
+      if (selection == null) {
+        continue;
+      }
+
+      TrackGroup trackGroup = selection.getTrackGroup();
+      int trackGroupIndex = checkNotNull(trackGroups).indexOf(trackGroup);
+      selectedLoadInfos.add(checkNotNull(rtspLoaderWrappers.get(trackGroupIndex)).loadInfo);
+
+      // Find the sampleStreamWrapper that contains this track group.
+      if (trackGroups.contains(trackGroup)) {
+        if (streams[i] == null) {
+          streams[i] = new SampleStreamImpl(trackGroupIndex);
+          // Update flag for newly created SampleStream.
+          streamResetFlags[i] = true;
+        }
+      }
+    }
+
+    // Cancel non-selected loadables.
+    for (int i = 0; i < rtspLoaderWrappers.size(); i++) {
+      RtspLoaderWrapper loadControl = rtspLoaderWrappers.get(i);
+      if (!selectedLoadInfos.contains(loadControl.loadInfo)) {
+        loadControl.cancelLoad();
+      }
+    }
+
+    trackSelected = true;
+    maybeSetupTracks();
+    return positionUs;
+  }
+
+  @Override
+  public void discardBuffer(long positionUs, boolean toKeyframe) {
+    if (isSeekPending()) {
+      return;
+    }
+
+    for (int i = 0; i < rtspLoaderWrappers.size(); i++) {
+      RtspLoaderWrapper loaderWrapper = rtspLoaderWrappers.get(i);
+      if (!loaderWrapper.canceled) {
+        loaderWrapper.sampleQueue.discardTo(positionUs, toKeyframe, /* stopAtReadPosition= */ true);
+      }
+    }
+  }
+
+  @Override
+  public long readDiscontinuity() {
+    return C.TIME_UNSET;
+  }
+
+  @Override
+  public long seekToUs(long positionUs) {
+    if (isSeekPending()) {
+      // TODO(internal b/172331505) Allow seek when a seek is pending.
+      // Does not allow another seek if a seek is pending.
+      return pendingSeekPositionUs;
+    }
+
+    if (seekInsideBufferUs(positionUs)) {
+      return positionUs;
+    }
+
+    pendingSeekPositionUs = positionUs;
+    rtspClient.seekToUs(positionUs);
+    for (int i = 0; i < rtspLoaderWrappers.size(); i++) {
+      rtspLoaderWrappers.get(i).seekTo(positionUs);
+    }
+    return positionUs;
+  }
+
+  @Override
+  public long getAdjustedSeekPositionUs(long positionUs, SeekParameters seekParameters) {
+    return positionUs;
+  }
+
+  @Override
+  public long getBufferedPositionUs() {
+    if (loadingFinished || rtspLoaderWrappers.isEmpty()) {
+      return C.TIME_END_OF_SOURCE;
+    }
+
+    if (isSeekPending()) {
+      return pendingSeekPositionUs;
+    }
+
+    long bufferedPositionUs = rtspLoaderWrappers.get(0).sampleQueue.getLargestQueuedTimestampUs();
+    for (int i = 1; i < rtspLoaderWrappers.size(); i++) {
+      bufferedPositionUs =
+          min(
+              bufferedPositionUs,
+              checkNotNull(rtspLoaderWrappers.get(i)).sampleQueue.getLargestQueuedTimestampUs());
+    }
+    return bufferedPositionUs;
+  }
+
+  @Override
+  public long getNextLoadPositionUs() {
+    return getBufferedPositionUs();
+  }
+
+  @Override
+  public boolean continueLoading(long positionUs) {
+    return isLoading();
+  }
+
+  @Override
+  public boolean isLoading() {
+    return !loadingFinished;
+  }
+
+  @Override
+  public void reevaluateBuffer(long positionUs) {
+    // Do nothing.
+  }
+
+  // SampleStream methods.
+
+  /* package */ boolean isReady(int trackGroupIndex) {
+    return rtspLoaderWrappers.get(trackGroupIndex).isSampleQueueReady();
+  }
+
+  @ReadDataResult
+  /* package */ int readData(
+      int sampleQueueIndex,
+      FormatHolder formatHolder,
+      DecoderInputBuffer buffer,
+      @ReadFlags int readFlags) {
+    return rtspLoaderWrappers.get(sampleQueueIndex).read(formatHolder, buffer, readFlags);
+  }
+
+  // Internal methods.
+
+  @Nullable
+  private RtpDataLoadable getLoadableByTrackUri(Uri trackUri) {
+    for (int i = 0; i < rtspLoaderWrappers.size(); i++) {
+      RtpLoadInfo loadInfo = rtspLoaderWrappers.get(i).loadInfo;
+      if (loadInfo.getTrackUri().equals(trackUri)) {
+        return loadInfo.loadable;
+      }
+    }
+    return null;
+  }
+
+  private boolean isSeekPending() {
+    return pendingSeekPositionUs != C.TIME_UNSET;
+  }
+
+  private void maybeFinishPrepare() {
+    if (released || prepared) {
+      return;
+    }
+
+    // Make sure all sample queues have got format assigned.
+    for (int i = 0; i < rtspLoaderWrappers.size(); i++) {
+      if (rtspLoaderWrappers.get(i).sampleQueue.getUpstreamFormat() == null) {
+        return;
+      }
+    }
+
+    prepared = true;
+    trackGroups = buildTrackGroups(ImmutableList.copyOf(rtspLoaderWrappers));
+    checkNotNull(callback).onPrepared(/* mediaPeriod= */ this);
+  }
+
+  /**
+   * Attempts to seek to the specified position within the sample queues.
+   *
+   * @param positionUs The seek position in microseconds.
+   * @return Whether the in-buffer seek was successful for all loading RTSP tracks.
+   */
+  private boolean seekInsideBufferUs(long positionUs) {
+    for (int i = 0; i < rtspLoaderWrappers.size(); i++) {
+      SampleQueue sampleQueue = rtspLoaderWrappers.get(i).sampleQueue;
+      if (!sampleQueue.seekTo(positionUs, /* allowTimeBeyondBuffer= */ false)) {
+        return false;
+      }
+    }
+    return true;
+  }
+
+  private void maybeSetupTracks() {
+    boolean transportReady = true;
+    for (int i = 0; i < selectedLoadInfos.size(); i++) {
+      transportReady &= selectedLoadInfos.get(i).isTransportReady();
+    }
+
+    if (transportReady && trackSelected) {
+      rtspClient.setupSelectedTracks(selectedLoadInfos);
+    }
+  }
+
+  private static ImmutableList<TrackGroup> buildTrackGroups(
+      ImmutableList<RtspLoaderWrapper> rtspLoaderWrappers) {
+    ImmutableList.Builder<TrackGroup> listBuilder = new ImmutableList.Builder<>();
+    SampleQueue sampleQueue;
+    for (int i = 0; i < rtspLoaderWrappers.size(); i++) {
+      sampleQueue = rtspLoaderWrappers.get(i).sampleQueue;
+      listBuilder.add(new TrackGroup(checkNotNull(sampleQueue.getUpstreamFormat())));
+    }
+    return listBuilder.build();
+  }
+
+  private final class InternalListener
+      implements ExtractorOutput,
+          Loader.Callback<RtpDataLoadable>,
+          UpstreamFormatChangedListener,
+          PlaybackEventListener {
+
+    // ExtractorOutput implementation.
+
+    @Override
+    public TrackOutput track(int id, int type) {
+      return checkNotNull(rtspLoaderWrappers.get(id)).sampleQueue;
+    }
+
+    @Override
+    public void endTracks() {
+      // TODO(b/172331505) Implement this method.
+    }
+
+    @Override
+    public void seekMap(SeekMap seekMap) {
+      // TODO(b/172331505) Implement this method.
+    }
+
+    // Loadable.Callback implementation.
+
+    @Override
+    public void onLoadCompleted(
+        RtpDataLoadable loadable, long elapsedRealtimeMs, long loadDurationMs) {}
+
+    @Override
+    public void onLoadCanceled(
+        RtpDataLoadable loadable, long elapsedRealtimeMs, long loadDurationMs, boolean released) {}
+
+    @Override
+    public Loader.LoadErrorAction onLoadError(
+        RtpDataLoadable loadable,
+        long elapsedRealtimeMs,
+        long loadDurationMs,
+        IOException error,
+        int errorCount) {
+      /* TODO(b/172331505) Sort out the retry policy.
+      Three cases for IOException:
+        - Socket open failure for RTP or RTCP.
+          - RETRY for the RTCP open failure.
+        - ExtractorInput read IOException (socket timeout, etc)
+          - Keep retrying unless playback is stopped.
+        - RtpPayloadReader consume ParserException (mal-formatted RTP packet)
+          - Don't retry? (if a packet is distorted on the fly, the packet is likely discarded by the
+           system, i.e. the server's sent a mal-formatted packet).
+      */
+      if (!prepared) {
+        preparationError = error;
+      } else {
+        if (error.getCause() instanceof SocketTimeoutException) {
+          handleSocketTimeout(loadable);
+        } else {
+          playbackException =
+              new RtspPlaybackException(
+                  /* message= */ loadable.rtspMediaTrack.uri.toString(), error);
+        }
+      }
+      return Loader.DONT_RETRY;
+    }
+
+    // SampleQueue.UpstreamFormatChangedListener implementation.
+
+    @Override
+    public void onUpstreamFormatChanged(Format format) {
+      handler.post(RtspMediaPeriod.this::maybeFinishPrepare);
+    }
+
+    // RtspClient.PlaybackEventListener implementation.
+
+    @Override
+    public void onRtspSetupCompleted() {
+      rtspClient.startPlayback(/* offsetMs= */ 0);
+    }
+
+    @Override
+    public void onPlaybackStarted(
+        long startPositionUs, ImmutableList<RtspTrackTiming> trackTimingList) {
+      // Validate that the trackTimingList contains timings for the selected tracks.
+      ArrayList<Uri> trackUrisWithTiming = new ArrayList<>(trackTimingList.size());
+      for (int i = 0; i < trackTimingList.size(); i++) {
+        trackUrisWithTiming.add(trackTimingList.get(i).uri);
+      }
+      for (int i = 0; i < selectedLoadInfos.size(); i++) {
+        RtpLoadInfo loadInfo = selectedLoadInfos.get(i);
+        if (!trackUrisWithTiming.contains(loadInfo.getTrackUri())) {
+          playbackException =
+              new RtspPlaybackException(
+                  "Server did not provide timing for track " + loadInfo.getTrackUri());
+          return;
+        }
+      }
+
+      for (int i = 0; i < trackTimingList.size(); i++) {
+        RtspTrackTiming trackTiming = trackTimingList.get(i);
+        @Nullable RtpDataLoadable dataLoadable = getLoadableByTrackUri(trackTiming.uri);
+        if (dataLoadable == null) {
+          continue;
+        }
+
+        dataLoadable.setTimestamp(trackTiming.rtpTimestamp);
+        dataLoadable.setSequenceNumber(trackTiming.sequenceNumber);
+
+        if (isSeekPending()) {
+          dataLoadable.seekToUs(startPositionUs, trackTiming.rtpTimestamp);
+        }
+      }
+
+      if (isSeekPending()) {
+        pendingSeekPositionUs = C.TIME_UNSET;
+      }
+    }
+
+    @Override
+    public void onPlaybackError(RtspPlaybackException error) {
+      playbackException = error;
+    }
+
+    /** Handles the {@link Loadable} whose {@link DataSource} timed out. */
+    private void handleSocketTimeout(RtpDataLoadable loadable) {
+      // TODO(b/172331505) Allow for retry when loading is not ending.
+      if (getBufferedPositionUs() == Long.MIN_VALUE) {
+        // Raise exception if no sample has been received so far.
+        playbackException = new RtspPlaybackException("Possible dropped UDP connection.");
+        return;
+      }
+
+      for (int i = 0; i < rtspLoaderWrappers.size(); i++) {
+        RtspLoaderWrapper loaderWrapper = rtspLoaderWrappers.get(i);
+        if (loaderWrapper.loadInfo.loadable == loadable) {
+          loaderWrapper.cancelLoad();
+          return;
+        }
+      }
+      playbackException = new RtspPlaybackException("Unknown loadable timed out.");
+    }
+  }
+
+  private final class SampleStreamImpl implements SampleStream {
+    private final int track;
+
+    public SampleStreamImpl(int track) {
+      this.track = track;
+    }
+
+    @Override
+    public boolean isReady() {
+      return RtspMediaPeriod.this.isReady(track);
+    }
+
+    @Override
+    public void maybeThrowError() throws RtspPlaybackException {
+      if (playbackException != null) {
+        throw playbackException;
+      }
+    }
+
+    @Override
+    public int readData(
+        FormatHolder formatHolder, DecoderInputBuffer buffer, @ReadFlags int readFlags) {
+      return RtspMediaPeriod.this.readData(track, formatHolder, buffer, readFlags);
+    }
+
+    @Override
+    public int skipData(long positionUs) {
+      return 0;
+    }
+  }
+
+  /** Manages the loading of an RTSP track. */
+  private final class RtspLoaderWrapper {
+    /** The {@link RtpLoadInfo} of the RTSP track to load. */
+    public final RtpLoadInfo loadInfo;
+
+    private final Loader loader;
+    private final SampleQueue sampleQueue;
+    private boolean canceled;
+    private boolean released;
+
+    /**
+     * Creates a new instance.
+     *
+     * <p>Instances must be {@link #release() released} after loadings conclude.
+     */
+    public RtspLoaderWrapper(RtspMediaTrack mediaTrack, int trackId) {
+      loadInfo = new RtpLoadInfo(mediaTrack, trackId);
+      loader = new Loader("ExoPlayer:RtspMediaPeriod:RtspDataLoader " + trackId);
+      sampleQueue = SampleQueue.createWithoutDrm(allocator);
+      sampleQueue.setUpstreamFormatChangeListener(internalListener);
+    }
+
+    /** Starts loading. */
+    public void startLoading() {
+      loader.startLoading(
+          loadInfo.loadable, /* callback= */ internalListener, /* defaultMinRetryCount= */ 0);
+    }
+
+    public boolean isSampleQueueReady() {
+      return sampleQueue.isReady(/* loadingFinished= */ canceled);
+    }
+
+    @ReadDataResult
+    public int read(
+        FormatHolder formatHolder, DecoderInputBuffer buffer, @ReadFlags int readFlags) {
+      return sampleQueue.read(formatHolder, buffer, readFlags, /* loadingFinished= */ canceled);
+    }
+
+    /** Cancels loading. */
+    public void cancelLoad() {
+      if (canceled) {
+        return;
+      }
+      loadInfo.loadable.cancelLoad();
+      canceled = true;
+
+      // Update loadingFinished every time loading is canceled.
+      for (int i = 0; i < rtspLoaderWrappers.size(); i++) {
+        loadingFinished &= rtspLoaderWrappers.get(i).canceled;
+      }
+    }
+
+    /** Resets the {@link Loadable} and {@link SampleQueue} to prepare for an RTSP seek. */
+    public void seekTo(long positionUs) {
+      loadInfo.loadable.resetForSeek();
+      sampleQueue.reset();
+      sampleQueue.setStartTimeUs(positionUs);
+    }
+
+    /** Releases the instance. */
+    public void release() {
+      if (released) {
+        return;
+      }
+      loader.release();
+      sampleQueue.release();
+      released = true;
+    }
+  }
+
+  /** Groups the info needed for loading one RTSP track in RTP. */
+  /* package */ final class RtpLoadInfo {
+    /** The {@link RtspMediaTrack}. */
+    public final RtspMediaTrack mediaTrack;
+
+    private final RtpDataLoadable loadable;
+
+    @Nullable private String transport;
+
+    /** Creates a new instance. */
+    public RtpLoadInfo(RtspMediaTrack mediaTrack, int trackId) {
+      this.mediaTrack = mediaTrack;
+
+      RtpDataLoadable.EventListener transportEventListener =
+          (transport) -> {
+            this.transport = transport;
+            maybeSetupTracks();
+          };
+      this.loadable =
+          new RtpDataLoadable(
+              trackId,
+              mediaTrack,
+              /* eventListener= */ transportEventListener,
+              /* output= */ internalListener);
+    }
+
+    /**
+     * Returns whether RTP transport is ready. Call {@link #getTransport()} only after transport is
+     * ready.
+     */
+    public boolean isTransportReady() {
+      return transport != null;
+    }
+
+    /**
+     * Gets the transport string for RTP loading.
+     *
+     * @throws IllegalStateException When transport for this RTP stream is not set.
+     */
+    public String getTransport() {
+      checkStateNotNull(transport);
+      return transport;
+    }
+
+    /** Gets the {@link Uri} for the loading RTSP track. */
+    public Uri getTrackUri() {
+      return loadable.rtspMediaTrack.uri;
+    }
+  }
+}

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/RtspMediaSource.java

@@ -0,0 +1,209 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.android.exoplayer2.source.rtsp;
+
+import static com.google.android.exoplayer2.ExoPlayerLibraryInfo.VERSION_SLASHY;
+import static com.google.android.exoplayer2.util.Assertions.checkNotNull;
+import static com.google.android.exoplayer2.util.Util.castNonNull;
+
+import androidx.annotation.Nullable;
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.MediaItem;
+import com.google.android.exoplayer2.drm.DrmSessionManager;
+import com.google.android.exoplayer2.drm.DrmSessionManagerProvider;
+import com.google.android.exoplayer2.source.BaseMediaSource;
+import com.google.android.exoplayer2.source.MediaPeriod;
+import com.google.android.exoplayer2.source.MediaSource;
+import com.google.android.exoplayer2.source.MediaSourceFactory;
+import com.google.android.exoplayer2.source.SinglePeriodTimeline;
+import com.google.android.exoplayer2.source.rtsp.RtspClient.SessionInfoListener;
+import com.google.android.exoplayer2.upstream.Allocator;
+import com.google.android.exoplayer2.upstream.HttpDataSource;
+import com.google.android.exoplayer2.upstream.LoadErrorHandlingPolicy;
+import com.google.android.exoplayer2.upstream.TransferListener;
+import com.google.android.exoplayer2.util.Util;
+import com.google.common.collect.ImmutableList;
+import java.io.IOException;
+import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
+
+/** An Rtsp {@link MediaSource} */
+public final class RtspMediaSource extends BaseMediaSource {
+
+  /**
+   * Factory for {@link RtspMediaSource}
+   *
+   * <p>This factory doesn't support the following methods from {@link MediaSourceFactory}:
+   *
+   * <ul>
+   *   <li>{@link #setDrmSessionManagerProvider(DrmSessionManagerProvider)}
+   *   <li>{@link #setDrmSessionManager(DrmSessionManager)}
+   *   <li>{@link #setDrmHttpDataSourceFactory(HttpDataSource.Factory)}
+   *   <li>{@link #setDrmUserAgent(String)}
+   *   <li>{@link #setLoadErrorHandlingPolicy(LoadErrorHandlingPolicy)}
+   * </ul>
+   */
+  public static final class Factory implements MediaSourceFactory {
+
+    /** @deprecated Not supported. */
+    @Deprecated
+    @Override
+    public Factory setDrmSessionManagerProvider(
+        @Nullable DrmSessionManagerProvider drmSessionManager) {
+      return this;
+    }
+
+    /** @deprecated Not supported. */
+    @Deprecated
+    @Override
+    public Factory setDrmSessionManager(@Nullable DrmSessionManager drmSessionManager) {
+      return this;
+    }
+
+    /** @deprecated Not supported. */
+    @Deprecated
+    @Override
+    public Factory setDrmHttpDataSourceFactory(
+        @Nullable HttpDataSource.Factory drmHttpDataSourceFactory) {
+      return this;
+    }
+
+    /** @deprecated Not supported. */
+    @Deprecated
+    @Override
+    public Factory setDrmUserAgent(@Nullable String userAgent) {
+      return this;
+    }
+
+    /** @deprecated Not supported. */
+    @Deprecated
+    @Override
+    public Factory setLoadErrorHandlingPolicy(
+        @Nullable LoadErrorHandlingPolicy loadErrorHandlingPolicy) {
+      return this;
+    }
+
+    @Override
+    public int[] getSupportedTypes() {
+      return new int[] {C.TYPE_RTSP};
+    }
+
+    /**
+     * Returns a new {@link RtspMediaSource} using the current parameters.
+     *
+     * @param mediaItem The {@link MediaItem}.
+     * @return The new {@link RtspMediaSource}.
+     * @throws NullPointerException if {@link MediaItem#playbackProperties} is {@code null}.
+     */
+    @Override
+    public RtspMediaSource createMediaSource(MediaItem mediaItem) {
+      checkNotNull(mediaItem.playbackProperties);
+      return new RtspMediaSource(mediaItem);
+    }
+  }
+
+  /** Thrown when an exception or error is encountered during loading an RTSP stream. */
+  public static final class RtspPlaybackException extends IOException {
+    public RtspPlaybackException(String message) {
+      super(message);
+    }
+
+    public RtspPlaybackException(Throwable e) {
+      super(e);
+    }
+
+    public RtspPlaybackException(String message, Throwable e) {
+      super(message, e);
+    }
+  }
+
+  private final MediaItem mediaItem;
+  private @MonotonicNonNull RtspClient rtspClient;
+
+  @Nullable private ImmutableList<RtspMediaTrack> rtspMediaTracks;
+  @Nullable private IOException sourcePrepareException;
+
+  private RtspMediaSource(MediaItem mediaItem) {
+    this.mediaItem = mediaItem;
+  }
+
+  @Override
+  protected void prepareSourceInternal(@Nullable TransferListener mediaTransferListener) {
+    checkNotNull(mediaItem.playbackProperties);
+    try {
+      rtspClient =
+          new RtspClient(
+              new SessionInfoListenerImpl(),
+              /* userAgent= */ VERSION_SLASHY,
+              mediaItem.playbackProperties.uri);
+      rtspClient.start();
+    } catch (IOException e) {
+      sourcePrepareException = new RtspPlaybackException("RtspClient not opened.", e);
+    }
+  }
+
+  @Override
+  protected void releaseSourceInternal() {
+    Util.closeQuietly(rtspClient);
+  }
+
+  @Override
+  public MediaItem getMediaItem() {
+    return mediaItem;
+  }
+
+  @Override
+  public void maybeThrowSourceInfoRefreshError() throws IOException {
+    if (sourcePrepareException != null) {
+      throw sourcePrepareException;
+    }
+  }
+
+  @Override
+  public MediaPeriod createPeriod(MediaPeriodId id, Allocator allocator, long startPositionUs) {
+    return new RtspMediaPeriod(allocator, checkNotNull(rtspMediaTracks), checkNotNull(rtspClient));
+  }
+
+  @Override
+  public void releasePeriod(MediaPeriod mediaPeriod) {
+    ((RtspMediaPeriod) mediaPeriod).release();
+  }
+
+  private final class SessionInfoListenerImpl implements SessionInfoListener {
+    @Override
+    public void onSessionTimelineUpdated(
+        RtspSessionTiming timing, ImmutableList<RtspMediaTrack> tracks) {
+      rtspMediaTracks = tracks;
+      refreshSourceInfo(
+          new SinglePeriodTimeline(
+              /* durationUs= */ C.msToUs(timing.getDurationMs()),
+              /* isSeekable= */ !timing.isLive(),
+              /* isDynamic= */ false,
+              /* useLiveConfiguration= */ timing.isLive(),
+              /* manifest= */ null,
+              mediaItem));
+    }
+
+    @Override
+    public void onSessionTimelineRequestFailed(String message, @Nullable Throwable cause) {
+      if (cause == null) {
+        sourcePrepareException = new RtspPlaybackException(message);
+      } else {
+        sourcePrepareException = new RtspPlaybackException(message, castNonNull(cause));
+      }
+    }
+  }
+}

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/RtspMediaTrack.java

@@ -0,0 +1,218 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.source.rtsp;
+
+import static com.google.android.exoplayer2.source.rtsp.rtp.RtpPayloadFormat.getMimeTypeFromRtpMediaType;
+import static com.google.android.exoplayer2.source.rtsp.sdp.MediaDescription.MEDIA_TYPE_AUDIO;
+import static com.google.android.exoplayer2.source.rtsp.sdp.SessionDescription.ATTR_CONTROL;
+import static com.google.android.exoplayer2.source.rtsp.sdp.SessionDescription.ATTR_RTPMAP;
+import static com.google.android.exoplayer2.util.Assertions.checkArgument;
+import static com.google.android.exoplayer2.util.Assertions.checkNotNull;
+import static com.google.android.exoplayer2.util.NalUnitUtil.NAL_START_CODE;
+import static com.google.android.exoplayer2.util.Util.castNonNull;
+
+import android.net.Uri;
+import android.util.Base64;
+import androidx.annotation.Nullable;
+import androidx.annotation.VisibleForTesting;
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.Format;
+import com.google.android.exoplayer2.audio.AacUtil;
+import com.google.android.exoplayer2.source.rtsp.rtp.RtpPayloadFormat;
+import com.google.android.exoplayer2.source.rtsp.sdp.MediaDescription;
+import com.google.android.exoplayer2.util.MimeTypes;
+import com.google.android.exoplayer2.util.NalUnitUtil;
+import com.google.android.exoplayer2.util.Util;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+
+/** Represents a media track in an RTSP playback. */
+public final class RtspMediaTrack {
+  // Format specific parameter names.
+  private static final String PARAMETER_PROFILE_LEVEL_ID = "profile-level-id";
+  private static final String PARAMETER_SPROP_PARAMS = "sprop-parameter-sets";
+  /** Prefix for the RFC6381 codecs string for AAC formats. */
+  private static final String AAC_CODECS_PREFIX = "mp4a.40.";
+  /** Prefix for the RFC6381 codecs string for AVC formats. */
+  private static final String H264_CODECS_PREFIX = "avc1.";
+
+  /** The track's associated {@link RtpPayloadFormat}. */
+  public final RtpPayloadFormat payloadFormat;
+  /** The track's URI. */
+  public final Uri uri;
+
+  /**
+   * Creates a new instance from a {@link MediaDescription}.
+   *
+   * @param mediaDescription The {@link MediaDescription} of this track.
+   * @param sessionUri The {@link Uri} of the RTSP playback session.
+   */
+  public RtspMediaTrack(MediaDescription mediaDescription, Uri sessionUri) {
+    checkArgument(mediaDescription.attributes.containsKey(ATTR_CONTROL));
+    payloadFormat = generatePayloadFormat(mediaDescription);
+    uri =
+        sessionUri
+            .buildUpon()
+            .appendEncodedPath(castNonNull(mediaDescription.attributes.get(ATTR_CONTROL)))
+            .build();
+  }
+
+  @Override
+  public boolean equals(@Nullable Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+    RtspMediaTrack that = (RtspMediaTrack) o;
+    return payloadFormat.equals(that.payloadFormat) && uri.equals(that.uri);
+  }
+
+  @Override
+  public int hashCode() {
+    int result = 7;
+    result = 31 * result + payloadFormat.hashCode();
+    result = 31 * result + uri.hashCode();
+    return result;
+  }
+
+  @VisibleForTesting
+  /* package */ static RtpPayloadFormat generatePayloadFormat(MediaDescription mediaDescription) {
+    Format.Builder formatBuilder = new Format.Builder();
+
+    if (mediaDescription.bitrate > 0) {
+      formatBuilder.setAverageBitrate(mediaDescription.bitrate);
+    }
+
+    // rtpmap is mandatory in an RTSP session with dynamic payload types (RFC2326 Section C.1.3).
+    checkArgument(mediaDescription.attributes.containsKey(ATTR_RTPMAP));
+    String rtpmapAttribute = castNonNull(mediaDescription.attributes.get(ATTR_RTPMAP));
+
+    // rtpmap string format: RFC2327 Page 22.
+    String[] rtpmap = Util.split(rtpmapAttribute, " ");
+    checkArgument(rtpmap.length == 2);
+    int rtpPayloadType = mediaDescription.rtpMapAttribute.payloadType;
+
+    String mimeType = getMimeTypeFromRtpMediaType(mediaDescription.rtpMapAttribute.mediaEncoding);
+    formatBuilder.setSampleMimeType(mimeType);
+
+    int clockRate = mediaDescription.rtpMapAttribute.clockRate;
+    int channelCount = C.INDEX_UNSET;
+    if (MEDIA_TYPE_AUDIO.equals(mediaDescription.mediaType)) {
+      channelCount =
+          inferChannelCount(mediaDescription.rtpMapAttribute.encodingParameters, mimeType);
+      formatBuilder.setSampleRate(clockRate).setChannelCount(channelCount);
+    }
+
+    ImmutableMap<String, String> fmtpParameters = mediaDescription.getFmtpParametersAsMap();
+    switch (mimeType) {
+      case MimeTypes.AUDIO_AAC:
+        checkArgument(channelCount != C.INDEX_UNSET);
+        checkArgument(!fmtpParameters.isEmpty());
+        processAacFmtpAttribute(formatBuilder, fmtpParameters, channelCount, clockRate);
+        break;
+      case MimeTypes.VIDEO_H264:
+        checkArgument(!fmtpParameters.isEmpty());
+        processH264FmtpAttribute(formatBuilder, fmtpParameters);
+        break;
+      case MimeTypes.AUDIO_AC3:
+        // AC3 does not require a FMTP attribute. Fall through.
+      default:
+        // Do nothing.
+    }
+
+    checkArgument(clockRate > 0);
+    // Checks if payload type is "dynamic" as defined in RFC3551 Section 3.
+    checkArgument(rtpPayloadType >= 96);
+    return new RtpPayloadFormat(formatBuilder.build(), rtpPayloadType, clockRate, fmtpParameters);
+  }
+
+  private static int inferChannelCount(int encodingParameter, String mimeType) {
+    if (encodingParameter != C.INDEX_UNSET) {
+      // The encoding parameter specifies the number of channels in audio streams when
+      // present. If omitted, the number of channels is one. This parameter has no significance in
+      // video streams. (RFC2327 Page 22).
+      return encodingParameter;
+    }
+
+    if (mimeType.equals(MimeTypes.AUDIO_AC3)) {
+      // If RTPMAP attribute does not include channel count for AC3, default to 6.
+      return 6;
+    }
+
+    return 1;
+  }
+
+  private static void processAacFmtpAttribute(
+      Format.Builder formatBuilder,
+      ImmutableMap<String, String> fmtpAttributes,
+      int channelCount,
+      int sampleRate) {
+    checkArgument(fmtpAttributes.containsKey(PARAMETER_PROFILE_LEVEL_ID));
+    String profileLevel = checkNotNull(fmtpAttributes.get(PARAMETER_PROFILE_LEVEL_ID));
+    formatBuilder.setCodecs(AAC_CODECS_PREFIX + profileLevel);
+    formatBuilder.setInitializationData(
+        ImmutableList.of(
+            // Clock rate equals to sample rate in RTP.
+            AacUtil.buildAacLcAudioSpecificConfig(sampleRate, channelCount)));
+  }
+
+  private static void processH264FmtpAttribute(
+      Format.Builder formatBuilder, ImmutableMap<String, String> fmtpAttributes) {
+    checkArgument(fmtpAttributes.containsKey(PARAMETER_PROFILE_LEVEL_ID));
+    String profileLevel = checkNotNull(fmtpAttributes.get(PARAMETER_PROFILE_LEVEL_ID));
+    formatBuilder.setCodecs(H264_CODECS_PREFIX + profileLevel);
+
+    checkArgument(fmtpAttributes.containsKey(PARAMETER_SPROP_PARAMS));
+    String spropParameterSets = checkNotNull(fmtpAttributes.get(PARAMETER_SPROP_PARAMS));
+    String[] parameterSets = Util.split(spropParameterSets, ",");
+    checkArgument(parameterSets.length == 2);
+    ImmutableList<byte[]> initializationData =
+        ImmutableList.of(
+            getH264InitializationDataFromParameterSet(parameterSets[0]),
+            getH264InitializationDataFromParameterSet(parameterSets[1]));
+    formatBuilder.setInitializationData(initializationData);
+
+    // Process SPS (Sequence Parameter Set).
+    byte[] spsNalDataWithStartCode = initializationData.get(0);
+    NalUnitUtil.SpsData spsData =
+        NalUnitUtil.parseSpsNalUnit(
+            spsNalDataWithStartCode, NAL_START_CODE.length, spsNalDataWithStartCode.length);
+    formatBuilder.setPixelWidthHeightRatio(spsData.pixelWidthAspectRatio);
+    formatBuilder.setHeight(spsData.height);
+    formatBuilder.setWidth(spsData.width);
+  }
+
+  private static byte[] getH264InitializationDataFromParameterSet(String parameterSet) {
+    byte[] decodedParameterNalData = Base64.decode(parameterSet, Base64.DEFAULT);
+    byte[] decodedParameterNalUnit =
+        new byte[decodedParameterNalData.length + NAL_START_CODE.length];
+    System.arraycopy(
+        NAL_START_CODE,
+        /* srcPos= */ 0,
+        decodedParameterNalUnit,
+        /* destPos= */ 0,
+        NAL_START_CODE.length);
+    System.arraycopy(
+        decodedParameterNalData,
+        /* srcPos= */ 0,
+        decodedParameterNalUnit,
+        /* destPos= */ NAL_START_CODE.length,
+        decodedParameterNalData.length);
+    return decodedParameterNalUnit;
+  }
+}

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/RtspSessionTiming.java

@@ -0,0 +1,105 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.source.rtsp;
+
+import static com.google.android.exoplayer2.util.Assertions.checkArgument;
+import static com.google.android.exoplayer2.util.Assertions.checkNotNull;
+
+import androidx.annotation.Nullable;
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.ParserException;
+import com.google.android.exoplayer2.util.Util;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+/**
+ * Represent the timing (RTSP Normal Playback Time format) of an RTSP session.
+ *
+ * <p>Currently only NPT is supported. See RFC2326 Section 3.6 for detail of NPT.
+ */
+public final class RtspSessionTiming {
+  /** The default session timing starting from 0.000 and indefinite length. */
+  public static final RtspSessionTiming DEFAULT =
+      new RtspSessionTiming(/* startTimeMs= */ 0, /* stopTimeMs= */ C.TIME_UNSET);
+
+  // We only support npt=xxx-[xxx], but not npt=-xxx. See RFC2326 Section 3.6.
+  private static final Pattern NPT_RANGE_PATTERN =
+      Pattern.compile("npt=([.\\d]+|now)\\s?-\\s?([.\\d]+)?");
+  private static final String START_TIMING_NTP_FORMAT = "npt=%.3f-";
+
+  private static final long LIVE_START_TIME = 0;
+
+  /** Parses an SDP range attribute (RFC2326 Section 3.6). */
+  public static RtspSessionTiming parseTiming(String sdpRangeAttribute) throws ParserException {
+    long startTimeMs;
+    long stopTimeMs;
+    Matcher matcher = NPT_RANGE_PATTERN.matcher(sdpRangeAttribute);
+    checkArgument(matcher.matches());
+
+    String startTimeString = checkNotNull(matcher.group(1));
+    if (startTimeString.equals("now")) {
+      startTimeMs = LIVE_START_TIME;
+    } else {
+      startTimeMs = (long) (Float.parseFloat(startTimeString) * C.MILLIS_PER_SECOND);
+    }
+
+    @Nullable String stopTimeString = matcher.group(2);
+    if (stopTimeString != null) {
+      try {
+        stopTimeMs = (long) (Float.parseFloat(stopTimeString) * C.MILLIS_PER_SECOND);
+      } catch (NumberFormatException e) {
+        throw new ParserException(e);
+      }
+      checkArgument(stopTimeMs > startTimeMs);
+    } else {
+      stopTimeMs = C.TIME_UNSET;
+    }
+
+    return new RtspSessionTiming(startTimeMs, stopTimeMs);
+  }
+
+  /** Gets a Range RTSP header for an RTSP PLAY request. */
+  public static String getOffsetStartTimeTiming(long offsetStartTimeMs) {
+    double offsetStartTimeSec = (double) offsetStartTimeMs / C.MILLIS_PER_SECOND;
+    return Util.formatInvariant(START_TIMING_NTP_FORMAT, offsetStartTimeSec);
+  }
+
+  /**
+   * The start time of this session, in milliseconds. When playing a live session, the start time is
+   * always zero.
+   */
+  public final long startTimeMs;
+  /**
+   * The stop time of the session, in milliseconds, or {@link C#TIME_UNSET} when the stop time is
+   * not set, for example when playing a live session.
+   */
+  public final long stopTimeMs;
+
+  private RtspSessionTiming(long startTimeMs, long stopTimeMs) {
+    this.startTimeMs = startTimeMs;
+    this.stopTimeMs = stopTimeMs;
+  }
+
+  /** Tests whether the timing is live. */
+  public boolean isLive() {
+    return stopTimeMs == C.TIME_UNSET;
+  }
+
+  /** Gets the session duration in milliseconds. */
+  public long getDurationMs() {
+    return stopTimeMs - startTimeMs;
+  }
+}

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/RtspTrackTiming.java

@@ -0,0 +1,114 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.source.rtsp;
+
+import android.net.Uri;
+import androidx.annotation.Nullable;
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.ParserException;
+import com.google.android.exoplayer2.source.rtsp.message.RtspHeaders;
+import com.google.android.exoplayer2.util.Util;
+import com.google.common.collect.ImmutableList;
+
+/**
+ * Represents an RTSP track's timing info, included as {@link RtspHeaders#RTP_INFO} in an RTSP PLAY
+ * response (RFC2326 Section 12.33).
+ *
+ * <p>The fields {@link #rtpTimestamp} and {@link #sequenceNumber} will not both be {@code null}.
+ */
+public final class RtspTrackTiming {
+
+  /**
+   * Parses the RTP-Info header into a list of {@link RtspTrackTiming RtspTrackTimings}.
+   *
+   * <p>The syntax of the RTP-Info (RFC2326 Section 12.33):
+   *
+   * <pre>
+   *   RTP-Info        = "RTP-Info" ":" 1#stream-url 1*parameter
+   *   stream-url      = "url" "=" url
+   *   parameter       = ";" "seq" "=" 1*DIGIT
+   *                   | ";" "rtptime" "=" 1*DIGIT
+   * </pre>
+   *
+   * <p>Examples from RFC2326:
+   *
+   * <pre>
+   *   RTP-Info:url=rtsp://foo.com/bar.file; seq=232433;rtptime=972948234
+   *   RTP-Info:url=rtsp://foo.com/bar.avi/streamid=0;seq=45102,
+   *            url=rtsp://foo.com/bar.avi/streamid=1;seq=30211
+   * </pre>
+   *
+   * @param rtpInfoString The value of the RTP-Info header, with header name (RTP-Info) removed.
+   * @return A list of parsed {@link RtspTrackTiming}.
+   * @throws ParserException If parsing failed.
+   */
+  public static ImmutableList<RtspTrackTiming> parseTrackTiming(String rtpInfoString)
+      throws ParserException {
+
+    ImmutableList.Builder<RtspTrackTiming> listBuilder = new ImmutableList.Builder<>();
+    for (String perTrackTimingString : Util.split(rtpInfoString, ",")) {
+      long rtpTime = C.TIME_UNSET;
+      int sequenceNumber = C.INDEX_UNSET;
+      @Nullable Uri uri = null;
+
+      for (String attributePair : Util.split(perTrackTimingString, ";")) {
+        try {
+          String[] attributes = Util.splitAtFirst(attributePair, "=");
+          String attributeName = attributes[0];
+          String attributeValue = attributes[1];
+
+          switch (attributeName) {
+            case "url":
+              uri = Uri.parse(attributeValue);
+              break;
+            case "seq":
+              sequenceNumber = Integer.parseInt(attributeValue);
+              break;
+            case "rtptime":
+              rtpTime = Long.parseLong(attributeValue);
+              break;
+            default:
+              throw new ParserException();
+          }
+        } catch (Exception e) {
+          throw new ParserException(attributePair, e);
+        }
+      }
+
+      if (uri == null
+          || uri.getScheme() == null // Checks if the URI is a URL.
+          || (sequenceNumber == C.INDEX_UNSET && rtpTime == C.TIME_UNSET)) {
+        throw new ParserException(perTrackTimingString);
+      }
+
+      listBuilder.add(new RtspTrackTiming(rtpTime, sequenceNumber, uri));
+    }
+    return listBuilder.build();
+  }
+
+  /** The timestamp of the next RTP packet, {@link C#TIME_UNSET} if not present. */
+  public final long rtpTimestamp;
+  /** The sequence number of the next RTP packet, {@link C#INDEX_UNSET} if not present. */
+  public final int sequenceNumber;
+  /** The {@link Uri} that identifies a matching {@link RtspMediaTrack}. */
+  public final Uri uri;
+
+  private RtspTrackTiming(long rtpTimestamp, int sequenceNumber, Uri uri) {
+    this.rtpTimestamp = rtpTimestamp;
+    this.sequenceNumber = sequenceNumber;
+    this.uri = uri;
+  }
+}

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/message/RtspDescribeResponse.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.source.rtsp.message;
+
+import com.google.android.exoplayer2.source.rtsp.sdp.SessionDescription;
+
+/** Represents an RTSP DESCRIBE response. */
+public final class RtspDescribeResponse {
+  /** The response's status code. */
+  public final int status;
+  /** The {@link SessionDescription} (see RFC2327) in the DESCRIBE response. */
+  public final SessionDescription sessionDescription;
+
+  /**
+   * Creates a new instance.
+   *
+   * @param status The response's status code.
+   * @param sessionDescription The {@link SessionDescription} in the DESCRIBE response.
+   */
+  public RtspDescribeResponse(int status, SessionDescription sessionDescription) {
+    this.status = status;
+    this.sessionDescription = sessionDescription;
+  }
+}

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/message/RtspHeaders.java

@@ -0,0 +1,166 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.android.exoplayer2.source.rtsp.message;
+
+import androidx.annotation.Nullable;
+import com.google.android.exoplayer2.util.Util;
+import com.google.common.base.Ascii;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+import java.util.ArrayList;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * RTSP message headers.
+ *
+ * <p>{@link Builder} must be used to construct an instance. Use {@link #get} to query header values
+ * with case-insensitive header names. The extra spaces around header names and values are trimmed.
+ * Contrary to HTTP, RTSP does not allow ambiguous/arbitrary header names (RFC 2326 Section 12).
+ */
+public final class RtspHeaders {
+
+  public static final String ACCEPT = "Accept";
+  public static final String ALLOW = "Allow";
+  public static final String AUTHORIZATION = "Authorization";
+  public static final String BANDWIDTH = "Bandwidth";
+  public static final String BLOCKSIZE = "Blocksize";
+  public static final String CACHE_CONTROL = "Cache-Control";
+  public static final String CONNECTION = "Connection";
+  public static final String CONTENT_BASE = "Content-Base";
+  public static final String CONTENT_ENCODING = "Content-Encoding";
+  public static final String CONTENT_LANGUAGE = "Content-Language";
+  public static final String CONTENT_LENGTH = "Content-Length";
+  public static final String CONTENT_LOCATION = "Content-Location";
+  public static final String CONTENT_TYPE = "Content-Type";
+  public static final String CSEQ = "CSeq";
+  public static final String DATE = "Date";
+  public static final String EXPIRES = "Expires";
+  public static final String PROXY_AUTHENTICATE = "Proxy-Authenticate";
+  public static final String PROXY_REQUIRE = "Proxy-Require";
+  public static final String PUBLIC = "Public";
+  public static final String RANGE = "Range";
+  public static final String RTP_INFO = "RTP-Info";
+  public static final String RTCP_INTERVAL = "RTCP-Interval";
+  public static final String SCALE = "Scale";
+  public static final String SESSION = "Session";
+  public static final String SPEED = "Speed";
+  public static final String SUPPORTED = "Supported";
+  public static final String TIMESTAMP = "Timestamp";
+  public static final String TRANSPORT = "Transport";
+  public static final String USER_AGENT = "User-Agent";
+  public static final String VIA = "Via";
+  public static final String WWW_AUTHENTICATE = "WWW-Authenticate";
+
+  /** Builds {@link RtspHeaders} instances. */
+  public static final class Builder {
+    private final List<String> namesAndValues;
+
+    /** Creates a new instance. */
+    public Builder() {
+      namesAndValues = new ArrayList<>();
+    }
+
+    /**
+     * Adds a header name and header value pair.
+     *
+     * @param headerName The name of the header.
+     * @param headerValue The value of the header.
+     * @return This builder.
+     */
+    public Builder add(String headerName, String headerValue) {
+      namesAndValues.add(headerName.trim());
+      namesAndValues.add(headerValue.trim());
+      return this;
+    }
+
+    /**
+     * Adds a list of headers.
+     *
+     * @param headers The list of headers, each item must following the format &lt;headerName&gt;:
+     *     &lt;headerValue&gt;
+     * @return This builder.
+     */
+    public Builder addAll(List<String> headers) {
+      for (int i = 0; i < headers.size(); i++) {
+        String[] header = Util.splitAtFirst(headers.get(i), ":\\s?");
+        if (header.length == 2) {
+          add(header[0], header[1]);
+        }
+      }
+      return this;
+    }
+
+    /**
+     * Adds multiple headers in a map.
+     *
+     * @param headers The map of headers, where the keys are the header names and the values are the
+     *     header values.
+     * @return This builder.
+     */
+    public Builder addAll(Map<String, String> headers) {
+      for (Map.Entry<String, String> header : headers.entrySet()) {
+        add(header.getKey(), header.getValue());
+      }
+      return this;
+    }
+
+    /**
+     * Builds a new {@link RtspHeaders} instance.
+     *
+     * @return The newly built {@link RtspHeaders} instance.
+     */
+    public RtspHeaders build() {
+      return new RtspHeaders(this);
+    }
+  }
+
+  private final ImmutableList<String> namesAndValues;
+
+  /**
+   * Gets the headers as a map, where the keys are the header names and values are the header
+   * values.
+   *
+   * @return The headers as a map. The keys of the map have follows those that are used to build
+   *     this {@link RtspHeaders} instance.
+   */
+  public ImmutableMap<String, String> asMap() {
+    Map<String, String> headers = new LinkedHashMap<>();
+    for (int i = 0; i < namesAndValues.size(); i += 2) {
+      headers.put(namesAndValues.get(i), namesAndValues.get(i + 1));
+    }
+    return ImmutableMap.copyOf(headers);
+  }
+
+  /**
+   * Returns a header value mapped to the argument, {@code null} if the header name is not recorded.
+   */
+  @Nullable
+  public String get(String headerName) {
+    for (int i = namesAndValues.size() - 2; i >= 0; i -= 2) {
+      if (Ascii.equalsIgnoreCase(headerName, namesAndValues.get(i))) {
+        return namesAndValues.get(i + 1);
+      }
+    }
+    return null;
+  }
+
+  private RtspHeaders(Builder builder) {
+    this.namesAndValues = ImmutableList.copyOf(builder.namesAndValues);
+  }
+}

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/message/RtspMessageChannel.java

@@ -0,0 +1,291 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.source.rtsp.message;
+
+import static com.google.android.exoplayer2.util.Assertions.checkStateNotNull;
+
+import android.os.Handler;
+import android.os.HandlerThread;
+import android.os.Looper;
+import android.util.Log;
+import com.google.android.exoplayer2.upstream.Loader;
+import com.google.android.exoplayer2.upstream.Loader.LoadErrorAction;
+import com.google.android.exoplayer2.upstream.Loader.Loadable;
+import com.google.android.exoplayer2.util.Util;
+import com.google.common.base.Charsets;
+import com.google.common.base.Joiner;
+import java.io.BufferedReader;
+import java.io.Closeable;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.OutputStream;
+import java.net.Socket;
+import java.util.ArrayList;
+import java.util.List;
+import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
+
+/** Sends and receives RTSP messages. */
+public final class RtspMessageChannel implements Closeable {
+
+  private static final String TAG = "RtspMessageChannel";
+  private static final boolean LOG_RTSP_MESSAGES = false;
+
+  /** A listener for received RTSP messages and possible failures. */
+  public interface MessageListener {
+
+    /**
+     * Called when an RTSP message is received.
+     *
+     * @param message The non-empty list of received lines, with line terminators removed.
+     */
+    void onRtspMessageReceived(List<String> message);
+
+    /**
+     * Called when failed to send an RTSP message.
+     *
+     * @param message The list of lines making up the RTSP message that is failed to send.
+     * @param e The thrown {@link Exception}.
+     */
+    default void onSendingFailed(List<String> message, Exception e) {}
+
+    /**
+     * Called when failed to receive an RTSP message.
+     *
+     * @param e The thrown {@link Exception}.
+     */
+    default void onReceivingFailed(Exception e) {}
+  }
+
+  /**
+   * The IANA-registered default port for RTSP. See <a
+   * href="https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml">here</a>
+   */
+  public static final int DEFAULT_RTSP_PORT = 554;
+
+  /**
+   * The handler for all {@code messageListener} interactions. Backed by the thread on which this
+   * class is constructed.
+   */
+  private final Handler messageListenerHandler;
+
+  private final MessageListener messageListener;
+  private final Loader receiverLoader;
+  private @MonotonicNonNull Sender sender;
+  private @MonotonicNonNull Socket socket;
+
+  private boolean closed;
+
+  /**
+   * Constructs a new instance.
+   *
+   * <p>The constructor must be called on a {@link Looper} thread. The thread is also where {@link
+   * MessageListener} events are sent. User must construct a socket for RTSP and call {@link
+   * #openSocket} to open the connection before being able to send and receive, and {@link #close}
+   * it when done.
+   *
+   * <p>Note: all method invocations must be made from the thread on which this class is created.
+   *
+   * @param messageListener The {@link MessageListener} to receive events.
+   */
+  public RtspMessageChannel(MessageListener messageListener) {
+    this.messageListenerHandler = Util.createHandlerForCurrentLooper();
+    this.messageListener = messageListener;
+    this.receiverLoader = new Loader("ExoPlayer:RtspMessageChannel:ReceiverLoader");
+  }
+
+  /**
+   * Opens the message channel to send and receive RTSP messages.
+   *
+   * <p>Note: If an {@link IOException} is thrown, callers must still call {@link #close()} to
+   * ensure that any partial effects of the invocation are cleaned up.
+   *
+   * @param socket An accepted {@link Socket}.
+   */
+  public void openSocket(Socket socket) throws IOException {
+    this.socket = socket;
+    sender = new Sender(socket.getOutputStream());
+
+    receiverLoader.startLoading(
+        new Receiver(socket.getInputStream()),
+        new LoaderCallbackImpl(),
+        /* defaultMinRetryCount= */ 0);
+  }
+
+  /**
+   * Closes the RTSP message channel.
+   *
+   * <p>The closed instance must not be re-opened again. The {@link MessageListener} will not
+   * receive further messages after closing.
+   *
+   * @throws IOException If an error occurs closing the message channel.
+   */
+  @Override
+  public void close() throws IOException {
+    if (sender != null) {
+      sender.close();
+    }
+    receiverLoader.release();
+
+    if (socket != null) {
+      socket.close();
+    }
+
+    messageListenerHandler.removeCallbacksAndMessages(/* token= */ null);
+    closed = true;
+  }
+
+  /**
+   * Sends a serialized RTSP message.
+   *
+   * @param message The list of strings representing the serialized RTSP message.
+   */
+  public void send(List<String> message) {
+    checkStateNotNull(sender);
+    sender.send(message);
+  }
+
+  private static void logMessage(List<String> rtspMessage) {
+    if (LOG_RTSP_MESSAGES) {
+      Log.d(TAG, Joiner.on('\n').join(rtspMessage));
+    }
+  }
+
+  private final class Sender implements Closeable {
+
+    private final OutputStream outputStream;
+    private final HandlerThread senderThread;
+    private final Handler senderThreadHandler;
+
+    /**
+     * Creates a new instance.
+     *
+     * @param outputStream The {@link OutputStream} of the opened RTSP {@link Socket}, to which the
+     *     request is sent. The caller needs to close the {@link OutputStream}.
+     */
+    public Sender(OutputStream outputStream) {
+      this.outputStream = outputStream;
+      this.senderThread = new HandlerThread("ExoPlayer:RtspMessageChannel:Sender");
+      this.senderThread.start();
+      this.senderThreadHandler = new Handler(this.senderThread.getLooper());
+    }
+
+    /**
+     * Sends out RTSP messages that are in the forms of lists of strings.
+     *
+     * <p>If {@link Exception} is thrown while sending, the message {@link
+     * MessageListener#onSendingFailed} is dispatched to the thread that created the {@link
+     * RtspMessageChannel}.
+     *
+     * @param message The must of strings representing the serialized RTSP message.
+     */
+    public void send(List<String> message) {
+      logMessage(message);
+      byte[] data = RtspMessageUtil.convertMessageToByteArray(message);
+      senderThreadHandler.post(
+          () -> {
+            try {
+              outputStream.write(data);
+            } catch (Exception e) {
+              messageListenerHandler.post(
+                  () -> {
+                    if (!closed) {
+                      messageListener.onSendingFailed(message, e);
+                    }
+                  });
+            }
+          });
+    }
+
+    @Override
+    public void close() {
+      senderThreadHandler.post(senderThread::quit);
+      try {
+        // Waits until all the messages posted to the sender thread are handled.
+        senderThread.join();
+      } catch (InterruptedException e) {
+        senderThread.interrupt();
+      }
+    }
+  }
+
+  /** A {@link Loadable} for receiving RTSP responses. */
+  private final class Receiver implements Loadable {
+    private final BufferedReader inputStreamReader;
+
+    private volatile boolean loadCanceled;
+
+    /**
+     * Creates a new instance.
+     *
+     * @param inputStream The {@link InputStream} of the opened RTSP {@link Socket}, from which the
+     *     {@link RtspResponse RtspResponses} are received. The caller needs to close the {@link
+     *     InputStream}.
+     */
+    public Receiver(InputStream inputStream) {
+      inputStreamReader = new BufferedReader(new InputStreamReader(inputStream, Charsets.UTF_8));
+    }
+
+    @Override
+    public void cancelLoad() {
+      loadCanceled = true;
+    }
+
+    @Override
+    public void load() throws IOException {
+      List<String> messageLines = new ArrayList<>();
+      while (!loadCanceled) {
+        String line;
+        while (inputStreamReader.ready() && (line = inputStreamReader.readLine()) != null) {
+          messageLines.add(line);
+        }
+
+        if (!messageLines.isEmpty()) {
+          List<String> message = new ArrayList<>(messageLines);
+          logMessage(message);
+          messageListenerHandler.post(
+              () -> {
+                if (!closed) {
+                  messageListener.onRtspMessageReceived(message);
+                }
+              });
+          // Resets for the next response.
+          messageLines.clear();
+        }
+      }
+    }
+  }
+
+  private final class LoaderCallbackImpl implements Loader.Callback<Receiver> {
+    @Override
+    public void onLoadCompleted(Receiver loadable, long elapsedRealtimeMs, long loadDurationMs) {}
+
+    @Override
+    public void onLoadCanceled(
+        Receiver loadable, long elapsedRealtimeMs, long loadDurationMs, boolean released) {}
+
+    @Override
+    public LoadErrorAction onLoadError(
+        Receiver loadable,
+        long elapsedRealtimeMs,
+        long loadDurationMs,
+        IOException error,
+        int errorCount) {
+      messageListener.onReceivingFailed(error);
+      return Loader.DONT_RETRY;
+    }
+  }
+}

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/message/RtspMessageUtil.java

@@ -0,0 +1,360 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.source.rtsp.message;
+
+import static com.google.android.exoplayer2.source.rtsp.message.RtspRequest.METHOD_ANNOUNCE;
+import static com.google.android.exoplayer2.source.rtsp.message.RtspRequest.METHOD_DESCRIBE;
+import static com.google.android.exoplayer2.source.rtsp.message.RtspRequest.METHOD_GET_PARAMETER;
+import static com.google.android.exoplayer2.source.rtsp.message.RtspRequest.METHOD_OPTIONS;
+import static com.google.android.exoplayer2.source.rtsp.message.RtspRequest.METHOD_PAUSE;
+import static com.google.android.exoplayer2.source.rtsp.message.RtspRequest.METHOD_PLAY;
+import static com.google.android.exoplayer2.source.rtsp.message.RtspRequest.METHOD_PLAY_NOTIFY;
+import static com.google.android.exoplayer2.source.rtsp.message.RtspRequest.METHOD_RECORD;
+import static com.google.android.exoplayer2.source.rtsp.message.RtspRequest.METHOD_REDIRECT;
+import static com.google.android.exoplayer2.source.rtsp.message.RtspRequest.METHOD_SETUP;
+import static com.google.android.exoplayer2.source.rtsp.message.RtspRequest.METHOD_SET_PARAMETER;
+import static com.google.android.exoplayer2.source.rtsp.message.RtspRequest.METHOD_TEARDOWN;
+import static com.google.android.exoplayer2.source.rtsp.message.RtspRequest.METHOD_UNSET;
+import static com.google.android.exoplayer2.util.Assertions.checkArgument;
+import static com.google.android.exoplayer2.util.Assertions.checkNotNull;
+
+import android.net.Uri;
+import androidx.annotation.Nullable;
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.ParserException;
+import com.google.android.exoplayer2.util.Util;
+import com.google.common.base.Charsets;
+import com.google.common.base.Joiner;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+import java.util.List;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+/** Utility methods for RTSP messages. */
+public final class RtspMessageUtil {
+  /** Represents a RTSP Session header (RFC2326 Section 12.37). */
+  public static final class RtspSessionHeader {
+    /** The session ID. */
+    public final String sessionId;
+    /**
+     * The session timeout, measured in milliseconds, {@link #DEFAULT_RTSP_TIMEOUT_MS} if not
+     * specified in the Session header.
+     */
+    public final long timeoutMs;
+
+    /** Creates a new instance. */
+    public RtspSessionHeader(String sessionId, long timeoutMs) {
+      this.sessionId = sessionId;
+      this.timeoutMs = timeoutMs;
+    }
+  }
+
+  /** The default timeout, in milliseconds, defined for RTSP (RFC2326 Section 12.37). */
+  public static final long DEFAULT_RTSP_TIMEOUT_MS = 60_000;
+
+  // Status line pattern, see RFC2326 Section 6.1.
+  private static final Pattern REQUEST_LINE_PATTERN = Pattern.compile("([A-Z_]+) (.*) RTSP/1\\.0");
+
+  // Status line pattern, see RFC2326 Section 7.1.
+  private static final Pattern STATUS_LINE_PATTERN = Pattern.compile("RTSP/1\\.0 (\\d+) (.+)");
+
+  // Session header pattern, see RFC2326 Section 12.37.
+  private static final Pattern SESSION_HEADER_PATTERN =
+      Pattern.compile("(\\w+)(?:;\\s?timeout=(\\d+))?");
+
+  private static final String RTSP_VERSION = "RTSP/1.0";
+
+  /**
+   * Serializes an {@link RtspRequest} to an {@link ImmutableList} of strings.
+   *
+   * @param request The {@link RtspRequest}.
+   * @return A list of the lines of the {@link RtspRequest}, without line terminators (CRLF).
+   */
+  public static ImmutableList<String> serializeRequest(RtspRequest request) {
+    ImmutableList.Builder<String> builder = new ImmutableList.Builder<>();
+    // Request line.
+    builder.add(
+        Util.formatInvariant(
+            "%s %s %s", toMethodString(request.method), request.uri, RTSP_VERSION));
+    ImmutableMap<String, String> headers = request.headers.asMap();
+    for (String headerName : headers.keySet()) {
+      builder.add(
+          Util.formatInvariant(
+              "%s: %s", headerName, checkNotNull(request.headers.get(headerName))));
+    }
+    // Empty line after headers.
+    builder.add("");
+    builder.add(request.messageBody);
+    return builder.build();
+  }
+
+  /**
+   * Serializes an {@link RtspResponse} to an {@link ImmutableList} of strings.
+   *
+   * @param response The {@link RtspResponse}.
+   * @return A list of the lines of the {@link RtspResponse}, without line terminators (CRLF).
+   */
+  public static ImmutableList<String> serializeResponse(RtspResponse response) {
+    ImmutableList.Builder<String> builder = new ImmutableList.Builder<>();
+    // Request line.
+    builder.add(
+        Util.formatInvariant(
+            "%s %s %s", RTSP_VERSION, response.status, getRtspStatusReasonPhrase(response.status)));
+
+    ImmutableMap<String, String> headers = response.headers.asMap();
+    for (String headerName : headers.keySet()) {
+      builder.add(
+          Util.formatInvariant(
+              "%s: %s", headerName, checkNotNull(response.headers.get(headerName))));
+    }
+    // Empty line after headers.
+    builder.add("");
+    builder.add(response.messageBody);
+    return builder.build();
+  }
+
+  /**
+   * Converts an RTSP message to a byte array.
+   *
+   * @param message The non-empty list of the lines of an RTSP message, with line terminators
+   *     removed.
+   */
+  public static byte[] convertMessageToByteArray(List<String> message) {
+    return Joiner.on("\r\n").join(message).getBytes(Charsets.UTF_8);
+  }
+
+  /** Removes the user info from the supplied {@link Uri}. */
+  public static Uri removeUserInfo(Uri uri) {
+    if (uri.getUserInfo() == null) {
+      return uri;
+    }
+
+    // The Uri must include a "@" if the user info is non-null.
+    String authorityWithUserInfo = checkNotNull(uri.getAuthority());
+    checkArgument(authorityWithUserInfo.contains("@"));
+    String authority = Util.split(authorityWithUserInfo, "@")[1];
+    return uri.buildUpon().encodedAuthority(authority).build();
+  }
+
+  /** Returns the corresponding String representation of the {@link RtspRequest.Method} argument. */
+  public static String toMethodString(@RtspRequest.Method int method) {
+    switch (method) {
+      case RtspRequest.METHOD_ANNOUNCE:
+        return "ANNOUNCE";
+      case METHOD_DESCRIBE:
+        return "DESCRIBE";
+      case METHOD_GET_PARAMETER:
+        return "GET_PARAMETER";
+      case METHOD_OPTIONS:
+        return "OPTIONS";
+      case METHOD_PAUSE:
+        return "PAUSE";
+      case METHOD_PLAY:
+        return "PLAY";
+      case METHOD_PLAY_NOTIFY:
+        return "PLAY_NOTIFY";
+      case METHOD_RECORD:
+        return "RECORD";
+      case METHOD_REDIRECT:
+        return "REDIRECT";
+      case METHOD_SETUP:
+        return "SETUP";
+      case METHOD_SET_PARAMETER:
+        return "SET_PARAMETER";
+      case METHOD_TEARDOWN:
+        return "TEARDOWN";
+      case METHOD_UNSET:
+      default:
+        throw new IllegalStateException();
+    }
+  }
+
+  @RtspRequest.Method
+  private static int parseMethodString(String method) {
+    switch (method) {
+      case "ANNOUNCE":
+        return METHOD_ANNOUNCE;
+      case "DESCRIBE":
+        return METHOD_DESCRIBE;
+      case "GET_PARAMETER":
+        return METHOD_GET_PARAMETER;
+      case "OPTIONS":
+        return METHOD_OPTIONS;
+      case "PAUSE":
+        return METHOD_PAUSE;
+      case "PLAY":
+        return METHOD_PLAY;
+      case "PLAY_NOTIFY":
+        return METHOD_PLAY_NOTIFY;
+      case "RECORD":
+        return METHOD_RECORD;
+      case "REDIRECT":
+        return METHOD_REDIRECT;
+      case "SETUP":
+        return METHOD_SETUP;
+      case "SET_PARAMETER":
+        return METHOD_SET_PARAMETER;
+      case "TEARDOWN":
+        return METHOD_TEARDOWN;
+      default:
+        throw new IllegalArgumentException();
+    }
+  }
+
+  /**
+   * Parses lines of a received RTSP response into an {@link RtspResponse} instance.
+   *
+   * @param lines The non-empty list of received lines, with line terminators removed.
+   * @return The parsed {@link RtspResponse} object.
+   */
+  public static RtspResponse parseResponse(List<String> lines) {
+    Matcher statusLineMatcher = STATUS_LINE_PATTERN.matcher(lines.get(0));
+    checkArgument(statusLineMatcher.matches());
+
+    int statusCode = Integer.parseInt(checkNotNull(statusLineMatcher.group(1)));
+    // An empty line marks the boundary between header and body.
+    int messageBodyOffset = lines.indexOf("");
+    checkArgument(messageBodyOffset > 0);
+
+    List<String> headerLines = lines.subList(1, messageBodyOffset);
+    RtspHeaders headers = new RtspHeaders.Builder().addAll(headerLines).build();
+
+    String messageBody = Joiner.on("\r\n").join(lines.subList(messageBodyOffset + 1, lines.size()));
+    return new RtspResponse(statusCode, headers, messageBody);
+  }
+
+  /**
+   * Parses lines of a received RTSP request into an {@link RtspRequest} instance.
+   *
+   * @param lines The non-empty list of received lines, with line terminators removed.
+   * @return The parsed {@link RtspRequest} object.
+   */
+  public static RtspRequest parseRequest(List<String> lines) {
+    Matcher requestMatcher = REQUEST_LINE_PATTERN.matcher(lines.get(0));
+    checkArgument(requestMatcher.matches());
+
+    @RtspRequest.Method int method = parseMethodString(checkNotNull(requestMatcher.group(1)));
+    Uri requestUri = Uri.parse(checkNotNull(requestMatcher.group(2)));
+    // An empty line marks the boundary between header and body.
+    int messageBodyOffset = lines.indexOf("");
+    checkArgument(messageBodyOffset > 0);
+
+    List<String> headerLines = lines.subList(1, messageBodyOffset);
+    RtspHeaders headers = new RtspHeaders.Builder().addAll(headerLines).build();
+
+    String messageBody = Joiner.on("\r\n").join(lines.subList(messageBodyOffset + 1, lines.size()));
+    return new RtspRequest(requestUri, method, headers, messageBody);
+  }
+
+  /**
+   * Parses the RTSP PUBLIC header into a list of RTSP methods.
+   *
+   * @param publicHeader The PUBLIC header content, null if not available.
+   * @return The list of supported RTSP methods, encoded in {@link RtspRequest.Method}, or an empty
+   *     list if the PUBLIC header is null.
+   */
+  public static ImmutableList<Integer> parsePublicHeader(@Nullable String publicHeader) {
+    if (publicHeader == null) {
+      return ImmutableList.of();
+    }
+
+    ImmutableList.Builder<Integer> methodListBuilder = new ImmutableList.Builder<>();
+    for (String method : Util.split(publicHeader, ",\\s?")) {
+      methodListBuilder.add(parseMethodString(method));
+    }
+    return methodListBuilder.build();
+  }
+
+  /**
+   * Parses a Session header in an RTSP message to {@link RtspSessionHeader}.
+   *
+   * <p>The format of the Session header is
+   *
+   * <pre>
+   * Session: session-id[;timeout=delta-seconds]
+   * </pre>
+   *
+   * @param headerValue The string represent the content without the header name (Session: ).
+   * @return The parsed {@link RtspSessionHeader}.
+   * @throws ParserException When the input header value does not follow the Session header format.
+   */
+  public static RtspSessionHeader parseSessionHeader(String headerValue) throws ParserException {
+    Matcher matcher = SESSION_HEADER_PATTERN.matcher(headerValue);
+    if (!matcher.matches()) {
+      throw new ParserException(headerValue);
+    }
+
+    String sessionId = checkNotNull(matcher.group(1));
+    // Optional parameter timeout.
+    long timeoutMs = DEFAULT_RTSP_TIMEOUT_MS;
+    @Nullable String timeoutString;
+    if ((timeoutString = matcher.group(2)) != null) {
+      try {
+        timeoutMs = Integer.parseInt(timeoutString) * C.MILLIS_PER_SECOND;
+      } catch (NumberFormatException e) {
+        throw new ParserException(e);
+      }
+    }
+
+    return new RtspSessionHeader(sessionId, timeoutMs);
+  }
+
+  private static String getRtspStatusReasonPhrase(int statusCode) {
+    switch (statusCode) {
+      case 200:
+        return "OK";
+      case 400:
+        return "Bad Request";
+      case 401:
+        return "Unauthorized";
+      case 404:
+        return "Not Found";
+      case 405:
+        return "Method Not Allowed";
+      case 454:
+        return "Session Not Found";
+      case 455:
+        return "Method Not Valid In This State";
+      case 456:
+        return "Header Field Not Valid";
+      case 457:
+        return "Invalid Range";
+      case 461:
+        return "Unsupported Transport";
+      case 500:
+        return "Internal Server Error";
+      case 505:
+        return "RTSP Version Not Supported";
+      default:
+        throw new IllegalArgumentException();
+    }
+  }
+
+  /**
+   * Parses the string argument as an integer, wraps the potential {@link NumberFormatException} in
+   * {@link ParserException}.
+   */
+  public static int parseInt(String intString) throws ParserException {
+    try {
+      return Integer.parseInt(intString);
+    } catch (NumberFormatException e) {
+      throw new ParserException(e);
+    }
+  }
+
+  private RtspMessageUtil() {}
+}

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/message/RtspOptionsResponse.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.source.rtsp.message;
+
+import com.google.common.collect.ImmutableList;
+import java.util.List;
+
+/** Represents an RTSP OPTIONS response. */
+// TODO(b/180434754) Move all classes under message to the parent rtsp package, and change the
+// visibility.
+public final class RtspOptionsResponse {
+  /** The response's status code. */
+  public final int status;
+  /**
+   * A list of methods supported by the RTSP server, encoded as {@link RtspRequest.Method}; or an
+   * empty list if the server does not disclose the supported methods.
+   */
+  public final ImmutableList<Integer> supportedMethods;
+
+  /**
+   * Creates a new instance.
+   *
+   * @param status The response's status code.
+   * @param supportedMethods A list of methods supported by the RTSP server, encoded as {@link
+   *     RtspRequest.Method}; or an empty list if such information is not available.
+   */
+  public RtspOptionsResponse(int status, List<Integer> supportedMethods) {
+    this.status = status;
+    this.supportedMethods = ImmutableList.copyOf(supportedMethods);
+  }
+}

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/message/RtspPlayResponse.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.source.rtsp.message;
+
+import com.google.android.exoplayer2.source.rtsp.RtspSessionTiming;
+import com.google.android.exoplayer2.source.rtsp.RtspTrackTiming;
+import com.google.common.collect.ImmutableList;
+import java.util.List;
+
+/** Represents an RTSP PLAY response. */
+public final class RtspPlayResponse {
+  /** The response's status code. */
+  public final int status;
+  /** The playback start timing, {@link RtspSessionTiming#DEFAULT} if not present. */
+  public final RtspSessionTiming sessionTiming;
+  /** The list of {@link RtspTrackTiming} representing the {@link RtspHeaders#RTP_INFO} header. */
+  public final ImmutableList<RtspTrackTiming> trackTimingList;
+
+  /**
+   * Creates a new instance.
+   *
+   * @param status The response's status code.
+   * @param sessionTiming The {@link RtspSessionTiming}, pass {@link RtspSessionTiming#DEFAULT} if
+   *     not present.
+   * @param trackTimingList The list of {@link RtspTrackTiming} representing the {@link
+   *     RtspHeaders#RTP_INFO} header.
+   */
+  public RtspPlayResponse(
+      int status, RtspSessionTiming sessionTiming, List<RtspTrackTiming> trackTimingList) {
+    this.status = status;
+    this.sessionTiming = sessionTiming;
+    this.trackTimingList = ImmutableList.copyOf(trackTimingList);
+  }
+}

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/message/RtspRequest.java

@@ -0,0 +1,105 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.android.exoplayer2.source.rtsp.message;
+
+import android.net.Uri;
+import androidx.annotation.IntDef;
+import java.lang.annotation.Documented;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+/** Represents an RTSP request. */
+public final class RtspRequest {
+  /**
+   * RTSP request methods, as defined in RFC2326 Section 10.
+   *
+   * <p>The possible values are:
+   *
+   * <ul>
+   *   <li>{@link #METHOD_UNSET}
+   *   <li>{@link #METHOD_ANNOUNCE}
+   *   <li>{@link #METHOD_DESCRIBE}
+   *   <li>{@link #METHOD_GET_PARAMETER}
+   *   <li>{@link #METHOD_OPTIONS}
+   *   <li>{@link #METHOD_PAUSE}
+   *   <li>{@link #METHOD_PLAY}
+   *   <li>{@link #METHOD_PLAY_NOTIFY}
+   *   <li>{@link #METHOD_RECORD}
+   *   <li>{@link #METHOD_REDIRECT}
+   *   <li>{@link #METHOD_SETUP}
+   *   <li>{@link #METHOD_SET_PARAMETER}
+   *   <li>{@link #METHOD_TEARDOWN}
+   * </ul>
+   */
+  @Documented
+  @Retention(RetentionPolicy.SOURCE)
+  @IntDef(
+      value = {
+        METHOD_UNSET,
+        METHOD_ANNOUNCE,
+        METHOD_DESCRIBE,
+        METHOD_GET_PARAMETER,
+        METHOD_OPTIONS,
+        METHOD_PAUSE,
+        METHOD_PLAY,
+        METHOD_PLAY_NOTIFY,
+        METHOD_RECORD,
+        METHOD_REDIRECT,
+        METHOD_SETUP,
+        METHOD_SET_PARAMETER,
+        METHOD_TEARDOWN
+      })
+  public @interface Method {}
+
+  public static final int METHOD_UNSET = 0;
+  public static final int METHOD_ANNOUNCE = 1;
+  public static final int METHOD_DESCRIBE = 2;
+  public static final int METHOD_GET_PARAMETER = 3;
+  public static final int METHOD_OPTIONS = 4;
+  public static final int METHOD_PAUSE = 5;
+  public static final int METHOD_PLAY = 6;
+  public static final int METHOD_PLAY_NOTIFY = 7;
+  public static final int METHOD_RECORD = 8;
+  public static final int METHOD_REDIRECT = 9;
+  public static final int METHOD_SETUP = 10;
+  public static final int METHOD_SET_PARAMETER = 11;
+  public static final int METHOD_TEARDOWN = 12;
+
+  /** The {@link Uri} to which this request is sent. */
+  public final Uri uri;
+  /** The request method, as defined in {@link Method}. */
+  @Method public final int method;
+  /** The headers of this request. */
+  public final RtspHeaders headers;
+  /** The body of this RTSP message, or empty string if absent. */
+  public final String messageBody;
+
+  /**
+   * Creates a new instance.
+   *
+   * @param uri The {@link Uri} to which this request is sent.
+   * @param method The request method, as defined in {@link Method}.
+   * @param headers The headers of this request.
+   * @param messageBody The body of this RTSP message, or empty string if absent.
+   */
+  public RtspRequest(Uri uri, @Method int method, RtspHeaders headers, String messageBody) {
+    this.uri = uri;
+    this.method = method;
+    this.headers = headers;
+    this.messageBody = messageBody;
+  }
+}

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/message/RtspResponse.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.android.exoplayer2.source.rtsp.message;
+
+/** Represents an RTSP Response. */
+public final class RtspResponse {
+  // TODO(b/172331505) Move this constant to MimeTypes.
+  /** The MIME type associated with Session Description Protocol (RFC4566). */
+  public static final String SDP_MIME_TYPE = "application/sdp";
+
+  /** The status code of this response, as defined in RFC 2326 section 11. */
+  public final int status;
+  /** The headers of this response. */
+  public final RtspHeaders headers;
+  /** The body of this RTSP message, or empty string if absent. */
+  public final String messageBody;
+
+  /**
+   * Creates a new instance.
+   *
+   * @param status The status code of this response, as defined in RFC 2326 section 11.
+   * @param headers The headers of this response.
+   * @param messageBody The body of this RTSP message, or empty string if absent.
+   */
+  public RtspResponse(int status, RtspHeaders headers, String messageBody) {
+    this.status = status;
+    this.headers = headers;
+    this.messageBody = messageBody;
+  }
+}

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/message/RtspSetupResponse.java

@@ -0,0 +1,43 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.source.rtsp.message;
+
+/** Represents an RTSP SETUP response. */
+// TODO(b/180434754) Move all classes under message to the parent rtsp package, and change the
+// visibility.
+public final class RtspSetupResponse {
+
+  /** The response's status code. */
+  public final int status;
+  /** The Session header (RFC2326 Section 12.37). */
+  public final RtspMessageUtil.RtspSessionHeader sessionHeader;
+  /** The Transport header (RFC2326 Section 12.39). */
+  public final String transport;
+
+  /**
+   * Creates a new instance.
+   *
+   * @param status The response's status code.
+   * @param sessionHeader The {@link RtspMessageUtil.RtspSessionHeader}.
+   * @param transport The transport header included in the RTSP SETUP response.
+   */
+  public RtspSetupResponse(
+      int status, RtspMessageUtil.RtspSessionHeader sessionHeader, String transport) {
+    this.status = status;
+    this.sessionHeader = sessionHeader;
+    this.transport = transport;
+  }
+}

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/message/package-info.java

@@ -0,0 +1,19 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+@NonNullApi
+package com.google.android.exoplayer2.source.rtsp.message;
+
+import com.google.android.exoplayer2.util.NonNullApi;

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/package-info.java

@@ -0,0 +1,19 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+@NonNullApi
+package com.google.android.exoplayer2.source.rtsp;
+
+import com.google.android.exoplayer2.util.NonNullApi;

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/rtp/RtpDataLoadable.java

@@ -0,0 +1,211 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.android.exoplayer2.source.rtsp.rtp;
+
+import static com.google.android.exoplayer2.util.Assertions.checkNotNull;
+import static com.google.android.exoplayer2.util.Util.closeQuietly;
+
+import android.net.Uri;
+import android.os.Handler;
+import androidx.annotation.Nullable;
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.extractor.DefaultExtractorInput;
+import com.google.android.exoplayer2.extractor.ExtractorInput;
+import com.google.android.exoplayer2.extractor.ExtractorOutput;
+import com.google.android.exoplayer2.extractor.PositionHolder;
+import com.google.android.exoplayer2.source.rtsp.RtspMediaTrack;
+import com.google.android.exoplayer2.upstream.DataSpec;
+import com.google.android.exoplayer2.upstream.Loader;
+import com.google.android.exoplayer2.upstream.UdpDataSource;
+import com.google.android.exoplayer2.util.Util;
+import java.io.IOException;
+import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
+
+/**
+ * A {@link Loader.Loadable} that sets up a sockets listening to incoming RTP traffic, carried by
+ * UDP packets.
+ *
+ * <p>Uses a {@link UdpDataSource} to listen on incoming packets. The local UDP port is selected by
+ * the runtime on opening; it also opens another {@link UdpDataSource} for RTCP on the RTP UDP port
+ * number plus one one. Pass a listener via constructor to receive a callback when the local port is
+ * opened. {@link #load} will throw an {@link IOException} if either of the two data sources fails
+ * to open.
+ *
+ * <p>Received RTP packets' payloads will be extracted by an {@link RtpExtractor}, and will be
+ * written to the {@link ExtractorOutput} instance provided at construction.
+ */
+public final class RtpDataLoadable implements Loader.Loadable {
+
+  /** Called on loadable events. */
+  public interface EventListener {
+    /**
+     * Called when the transport information for receiving incoming RTP and RTCP packets is ready.
+     *
+     * @param transport The RTSP transport (RFC2326 Section 12.39) including the client data port
+     *     and RTCP port.
+     */
+    void onTransportReady(String transport);
+  }
+
+  private static final String DEFAULT_TRANSPORT_FORMAT = "RTP/AVP;unicast;client_port=%d-%d";
+
+  private static final String RTP_ANY_INCOMING_IPV4 = "rtp://0.0.0.0";
+  // Using port zero will cause the system to generate a port.
+  private static final int RTP_LOCAL_PORT = 0;
+  private static final String RTP_BIND_ADDRESS = RTP_ANY_INCOMING_IPV4 + ":" + RTP_LOCAL_PORT;
+
+  /** The track ID associated with the Loadable. */
+  public final int trackId;
+  /** The {@link RtspMediaTrack} to load. */
+  public final RtspMediaTrack rtspMediaTrack;
+
+  private final EventListener eventListener;
+  private final ExtractorOutput output;
+  private final Handler playbackThreadHandler;
+
+  private @MonotonicNonNull RtpExtractor extractor;
+
+  private volatile boolean loadCancelled;
+  private volatile long pendingSeekPositionUs;
+  private volatile long nextRtpTimestamp;
+
+  /**
+   * Creates an {@link RtpDataLoadable} that listens on incoming RTP traffic.
+   *
+   * <p>Caller of this constructor must be on playback thread.
+   *
+   * @param trackId The track ID associated with the Loadable.
+   * @param rtspMediaTrack The {@link RtspMediaTrack} to load.
+   * @param eventListener The {@link EventListener}.
+   * @param output A {@link ExtractorOutput} instance to which the received and extracted data will
+   */
+  public RtpDataLoadable(
+      int trackId,
+      RtspMediaTrack rtspMediaTrack,
+      EventListener eventListener,
+      ExtractorOutput output) {
+    this.trackId = trackId;
+    this.rtspMediaTrack = rtspMediaTrack;
+    this.eventListener = eventListener;
+    this.output = output;
+    this.playbackThreadHandler = Util.createHandlerForCurrentLooper();
+    pendingSeekPositionUs = C.TIME_UNSET;
+  }
+
+  /**
+   * Sets the timestamp of an RTP packet to arrive.
+   *
+   * @param timestamp The timestamp of the RTP packet to arrive. Supply {@link C#TIME_UNSET} if its
+   *     unavailable.
+   */
+  public void setTimestamp(long timestamp) {
+    if (timestamp != C.TIME_UNSET) {
+      if (!checkNotNull(extractor).hasReadFirstRtpPacket()) {
+        extractor.setFirstTimestamp(timestamp);
+      }
+    }
+  }
+
+  /**
+   * Sets the timestamp of an RTP packet to arrive.
+   *
+   * @param sequenceNumber The sequence number of the RTP packet to arrive. Supply {@link
+   *     C#INDEX_UNSET} if its unavailable.
+   */
+  public void setSequenceNumber(int sequenceNumber) {
+    if (!checkNotNull(extractor).hasReadFirstRtpPacket()) {
+      extractor.setFirstSequenceNumber(sequenceNumber);
+    }
+  }
+
+  @Override
+  public void cancelLoad() {
+    loadCancelled = true;
+  }
+
+  @Override
+  public void load() throws IOException {
+    @Nullable UdpDataSource firstDataSource = null;
+    @Nullable UdpDataSource secondDataSource = null;
+
+    try {
+      // Open and set up the data sources.
+      // From RFC3550 Section 11: "For UDP and similar protocols, RTP SHOULD use an even destination
+      // port number and the corresponding RTCP stream SHOULD use the next higher (odd) destination
+      // port number". Some RTSP servers are strict about this rule.
+      // We open a data source first, and depending its port number, open the next data source with
+      // a port number that is either the higher or the lower.
+      firstDataSource = new UdpDataSource();
+      firstDataSource.open(new DataSpec(Uri.parse(RTP_BIND_ADDRESS)));
+
+      int firstPort = firstDataSource.getLocalPort();
+      boolean isFirstPortNumberEven = (firstPort % 2 == 0);
+      int secondPort = isFirstPortNumberEven ? firstPort + 1 : firstPort - 1;
+
+      // RTCP always uses the immediate next port.
+      secondDataSource = new UdpDataSource();
+      secondDataSource.open(new DataSpec(Uri.parse(RTP_ANY_INCOMING_IPV4 + ":" + secondPort)));
+
+      // RTP data port is always the lower and even-numbered port.
+      UdpDataSource dataSource = isFirstPortNumberEven ? firstDataSource : secondDataSource;
+      int dataPort = dataSource.getLocalPort();
+      int rtcpPort = dataPort + 1;
+      String transport = Util.formatInvariant(DEFAULT_TRANSPORT_FORMAT, dataPort, rtcpPort);
+      playbackThreadHandler.post(() -> eventListener.onTransportReady(transport));
+
+      // Sets up the extractor.
+      ExtractorInput extractorInput =
+          new DefaultExtractorInput(
+              checkNotNull(dataSource), /* position= */ 0, /* length= */ C.LENGTH_UNSET);
+      extractor = new RtpExtractor(rtspMediaTrack.payloadFormat, trackId);
+      extractor.init(output);
+
+      while (!loadCancelled) {
+        if (pendingSeekPositionUs != C.TIME_UNSET) {
+          extractor.seek(nextRtpTimestamp, pendingSeekPositionUs);
+          pendingSeekPositionUs = C.TIME_UNSET;
+        }
+
+        extractor.read(extractorInput, /* seekPosition= */ new PositionHolder());
+      }
+    } finally {
+      closeQuietly(firstDataSource);
+      closeQuietly(secondDataSource);
+    }
+  }
+
+  /**
+   * Signals when performing an RTSP seek that involves RTSP message exchange.
+   *
+   * <p>{@link #seekToUs} must be called after the seek is successful.
+   */
+  public void resetForSeek() {
+    checkNotNull(extractor).preSeek();
+  }
+
+  /**
+   * Sets the correct start position and RTP timestamp after a successful RTSP seek.
+   *
+   * @param positionUs The position in microseconds from the start, from which the server starts
+   *     play.
+   * @param nextRtpTimestamp The first RTP packet's timestamp after the seek.
+   */
+  public void seekToUs(long positionUs, long nextRtpTimestamp) {
+    pendingSeekPositionUs = positionUs;
+    this.nextRtpTimestamp = nextRtpTimestamp;
+  }
+}

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/rtp/RtpExtractor.java

@@ -0,0 +1,205 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.android.exoplayer2.source.rtsp.rtp;
+
+import static com.google.android.exoplayer2.util.Assertions.checkNotNull;
+
+import android.os.SystemClock;
+import androidx.annotation.GuardedBy;
+import androidx.annotation.Nullable;
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.extractor.Extractor;
+import com.google.android.exoplayer2.extractor.ExtractorInput;
+import com.google.android.exoplayer2.extractor.ExtractorOutput;
+import com.google.android.exoplayer2.extractor.PositionHolder;
+import com.google.android.exoplayer2.extractor.SeekMap;
+import com.google.android.exoplayer2.source.rtsp.rtp.reader.DefaultRtpPayloadReaderFactory;
+import com.google.android.exoplayer2.source.rtsp.rtp.reader.RtpPayloadReader;
+import com.google.android.exoplayer2.util.ParsableByteArray;
+import java.io.IOException;
+import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
+
+/** Extracts data from RTP packets. */
+/* package */ final class RtpExtractor implements Extractor {
+
+  private final RtpPayloadReader payloadReader;
+  private final ParsableByteArray rtpPacketScratchBuffer;
+  private final ParsableByteArray rtpPacketDataBuffer;
+  private final int trackId;
+  private final Object lock;
+  private final RtpPacketReorderingQueue reorderingQueue;
+
+  private @MonotonicNonNull ExtractorOutput output;
+  private boolean firstPacketRead;
+  private volatile long firstTimestamp;
+  private volatile int firstSequenceNumber;
+
+  @GuardedBy("lock")
+  private boolean isSeekPending;
+
+  @GuardedBy("lock")
+  private long nextRtpTimestamp;
+
+  @GuardedBy("lock")
+  private long playbackStartTimeUs;
+
+  public RtpExtractor(RtpPayloadFormat payloadFormat, int trackId) {
+    this.trackId = trackId;
+
+    payloadReader =
+        checkNotNull(new DefaultRtpPayloadReaderFactory().createPayloadReader(payloadFormat));
+    rtpPacketScratchBuffer = new ParsableByteArray(RtpPacket.MAX_SIZE);
+    rtpPacketDataBuffer = new ParsableByteArray();
+    lock = new Object();
+    reorderingQueue = new RtpPacketReorderingQueue();
+    firstTimestamp = C.TIME_UNSET;
+    firstSequenceNumber = C.INDEX_UNSET;
+    nextRtpTimestamp = C.TIME_UNSET;
+    playbackStartTimeUs = C.TIME_UNSET;
+  }
+
+  /** Sets the timestamp of the first RTP packet to arrive. */
+  public void setFirstTimestamp(long firstTimestamp) {
+    this.firstTimestamp = firstTimestamp;
+  }
+
+  /** Sets the sequence number of the first RTP packet to arrive. */
+  public void setFirstSequenceNumber(int firstSequenceNumber) {
+    this.firstSequenceNumber = firstSequenceNumber;
+  }
+
+  /** Returns whether the first RTP packet is processed. */
+  public boolean hasReadFirstRtpPacket() {
+    return firstPacketRead;
+  }
+
+  /**
+   * Signals when performing an RTSP seek that involves RTSP message exchange.
+   *
+   * <p>{@link #seek} must be called after a successful RTSP seek.
+   *
+   * <p>After this method in called, the incoming RTP packets are read from the {@link
+   * ExtractorInput}, but they are not further processed by the {@link RtpPayloadReader readers}.
+   *
+   * <p>The user must clear the {@link ExtractorOutput} after calling this method, to ensure no
+   * samples are written to {@link ExtractorOutput}.
+   */
+  public void preSeek() {
+    synchronized (lock) {
+      isSeekPending = true;
+    }
+  }
+
+  @Override
+  public boolean sniff(ExtractorInput input) {
+    // TODO(b/172331505) Build sniff support.
+    return false;
+  }
+
+  @Override
+  public void init(ExtractorOutput output) {
+    payloadReader.createTracks(output, trackId);
+    output.endTracks();
+    // TODO(b/172331505) replace hardcoded unseekable seekmap.
+    output.seekMap(new SeekMap.Unseekable(C.TIME_UNSET));
+    this.output = output;
+  }
+
+  @Override
+  public int read(ExtractorInput input, PositionHolder seekPosition) throws IOException {
+    checkNotNull(output); // Asserts init is called.
+
+    // Reads one RTP packet at a time.
+    int bytesRead = input.read(rtpPacketScratchBuffer.getData(), 0, RtpPacket.MAX_SIZE);
+    if (bytesRead == RESULT_END_OF_INPUT) {
+      return RESULT_END_OF_INPUT;
+    } else if (bytesRead == 0) {
+      return RESULT_CONTINUE;
+    }
+
+    rtpPacketScratchBuffer.setPosition(0);
+    rtpPacketScratchBuffer.setLimit(bytesRead);
+    @Nullable RtpPacket packet = RtpPacket.parse(rtpPacketScratchBuffer);
+    if (packet == null) {
+      return RESULT_CONTINUE;
+    }
+
+    long packetArrivalTimeMs = SystemClock.elapsedRealtime();
+    reorderingQueue.offer(packet, packetArrivalTimeMs);
+    @Nullable RtpPacket dequeuedPacket = reorderingQueue.poll(getCutoffTimeMs(packetArrivalTimeMs));
+    if (dequeuedPacket == null) {
+      // No packet is available for reading.
+      return RESULT_CONTINUE;
+    }
+    packet = dequeuedPacket;
+
+    if (!firstPacketRead) {
+      // firstTimestamp and firstSequenceNumber are transmitted over RTSP. There is no guarantee
+      // that they arrive before the RTP packets. We use whichever comes first.
+      if (firstTimestamp == C.TIME_UNSET) {
+        firstTimestamp = packet.timestamp;
+      }
+      if (firstSequenceNumber == C.INDEX_UNSET) {
+        firstSequenceNumber = packet.sequenceNumber;
+      }
+      payloadReader.onReceivingFirstPacket(firstTimestamp, firstSequenceNumber);
+      firstPacketRead = true;
+    }
+
+    synchronized (lock) {
+      // Ignores the incoming packets while seek is pending.
+      if (isSeekPending) {
+        if (nextRtpTimestamp != C.TIME_UNSET && playbackStartTimeUs != C.TIME_UNSET) {
+          payloadReader.seek(nextRtpTimestamp, playbackStartTimeUs);
+          isSeekPending = false;
+          nextRtpTimestamp = C.TIME_UNSET;
+          playbackStartTimeUs = C.TIME_UNSET;
+        }
+      } else {
+        rtpPacketDataBuffer.reset(packet.payloadData);
+        payloadReader.consume(
+            rtpPacketDataBuffer, packet.timestamp, packet.sequenceNumber, packet.marker);
+      }
+    }
+    return RESULT_CONTINUE;
+  }
+
+  @Override
+  public void seek(long nextRtpTimestamp, long playbackStartTimeUs) {
+    synchronized (lock) {
+      this.nextRtpTimestamp = nextRtpTimestamp;
+      this.playbackStartTimeUs = playbackStartTimeUs;
+    }
+  }
+
+  @Override
+  public void release() {
+    // Do nothing.
+  }
+
+  /**
+   * Returns the cutoff time of waiting for an out-of-order packet.
+   *
+   * <p>Returns the cutoff time to pass to {@link RtpPacketReorderingQueue#poll(long)} based on the
+   * given RtpPacket arrival time.
+   */
+  private static long getCutoffTimeMs(long packetArrivalTimeMs) {
+    // TODO(internal b/172331505) 30ms is roughly the time for one video frame. It is not rigorously
+    // chosen and will need fine tuning in the future.
+    return packetArrivalTimeMs - 30;
+  }
+}

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/rtp/RtpPacket.java

@@ -0,0 +1,324 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.android.exoplayer2.source.rtsp.rtp;
+
+import static com.google.android.exoplayer2.util.Assertions.checkArgument;
+import static com.google.android.exoplayer2.util.Assertions.checkNotNull;
+
+import androidx.annotation.Nullable;
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.util.ParsableByteArray;
+import com.google.android.exoplayer2.util.Util;
+import java.nio.ByteBuffer;
+
+/**
+ * Represents the header and the payload of an RTP packet.
+ *
+ * <p>Not supported parsing at the moment: header extension and CSRC.
+ *
+ * <p>Structure of an RTP header (RFC3550, Section 5.1).
+ *
+ * <pre>
+ *  0                   1                   2                   3
+ *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |V=2|P|X|  CC   |M|     PT      |       sequence number         |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |                           timestamp                           |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |           synchronization source (SSRC) identifier            |
+ * +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
+ * |            contributing source (CSRC) identifiers             |
+ * |                             ....                              |
+ * +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
+ * | Profile-specific extension ID |   Extension header length     |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |                       Extension header                        |
+ * |                             ....                              |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *    3                   2                   1
+ *  1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
+ * </pre>
+ */
+public final class RtpPacket {
+
+  /** Builder class for an {@link RtpPacket} */
+  public static final class Builder {
+    private boolean padding;
+    private boolean marker;
+    private byte payloadType;
+    private int sequenceNumber;
+    private long timestamp;
+    private int ssrc;
+    private byte[] csrc = EMPTY;
+    private byte[] payloadData = EMPTY;
+
+    /** Sets the {@link RtpPacket#padding}. The default is false. */
+    public Builder setPadding(boolean padding) {
+      this.padding = padding;
+      return this;
+    }
+
+    /** Sets {@link RtpPacket#marker}. The default is false. */
+    public Builder setMarker(boolean marker) {
+      this.marker = marker;
+      return this;
+    }
+
+    /** Sets {@link RtpPacket#payloadType}. The default is 0. */
+    public Builder setPayloadType(byte payloadType) {
+      this.payloadType = payloadType;
+      return this;
+    }
+
+    /** Sets {@link RtpPacket#sequenceNumber}. The default is 0. */
+    public Builder setSequenceNumber(int sequenceNumber) {
+      checkArgument(sequenceNumber >= MIN_SEQUENCE_NUMBER && sequenceNumber <= MAX_SEQUENCE_NUMBER);
+      this.sequenceNumber = sequenceNumber & 0xFFFF;
+      return this;
+    }
+
+    /** Sets {@link RtpPacket#timestamp}. The default is 0. */
+    public Builder setTimestamp(long timestamp) {
+      this.timestamp = timestamp;
+      return this;
+    }
+
+    /** Sets {@link RtpPacket#ssrc}. The default is 0. */
+    public Builder setSsrc(int ssrc) {
+      this.ssrc = ssrc;
+      return this;
+    }
+
+    /** Sets {@link RtpPacket#csrc}. The default is an empty byte array. */
+    public Builder setCsrc(byte[] csrc) {
+      checkNotNull(csrc);
+      this.csrc = csrc;
+      return this;
+    }
+
+    /** Sets {@link RtpPacket#payloadData}. The default is an empty byte array. */
+    public Builder setPayloadData(byte[] payloadData) {
+      checkNotNull(payloadData);
+      this.payloadData = payloadData;
+      return this;
+    }
+
+    /** Builds the {@link RtpPacket}. */
+    public RtpPacket build() {
+      return new RtpPacket(this);
+    }
+  }
+
+  public static final int RTP_VERSION = 2;
+
+  public static final int MAX_SIZE = 65507;
+  public static final int MIN_HEADER_SIZE = 12;
+  public static final int MIN_SEQUENCE_NUMBER = 0;
+  public static final int MAX_SEQUENCE_NUMBER = 0xFFFF;
+  public static final int CSRC_SIZE = 4;
+
+  private static final byte[] EMPTY = new byte[0];
+
+  /** The RTP version field (Word 0, bits 0-1), should always be 2. */
+  public final byte version = RTP_VERSION;
+  /** The RTP padding bit (Word 0, bit 2). */
+  public final boolean padding;
+  /** The RTP extension bit (Word 0, bit 3). */
+  public final boolean extension;
+  /** The RTP CSRC count field (Word 0, bits 4-7). */
+  public final byte csrcCount;
+
+  /** The RTP marker bit (Word 0, bit 8). */
+  public final boolean marker;
+  /** The RTP CSRC count field (Word 0, bits 9-15). */
+  public final byte payloadType;
+
+  /** The RTP sequence number field (Word 0, bits 16-31). */
+  public final int sequenceNumber;
+
+  /** The RTP timestamp field (Word 1). */
+  public final long timestamp;
+
+  /** The RTP SSRC field (Word 2). */
+  public final int ssrc;
+
+  /** The RTP CSRC fields (Optional, up to 15 items). */
+  public final byte[] csrc;
+
+  public final byte[] payloadData;
+
+  /**
+   * Creates an {@link RtpPacket} from a {@link ParsableByteArray}.
+   *
+   * @param packetBuffer The buffer that contains the RTP packet data.
+   * @return The built {@link RtpPacket}.
+   */
+  @Nullable
+  public static RtpPacket parse(ParsableByteArray packetBuffer) {
+    if (packetBuffer.bytesLeft() < MIN_HEADER_SIZE) {
+      return null;
+    }
+
+    // Word 0.
+    int firstByte = packetBuffer.readUnsignedByte();
+    byte version = (byte) (firstByte >> 6);
+    boolean padding = ((firstByte >> 5) & 0x1) == 1;
+    byte csrcCount = (byte) (firstByte & 0xF);
+
+    if (version != RTP_VERSION) {
+      return null;
+    }
+
+    int secondByte = packetBuffer.readUnsignedByte();
+    boolean marker = ((secondByte >> 7) & 0x1) == 1;
+    byte payloadType = (byte) (secondByte & 0x7F);
+
+    int sequenceNumber = packetBuffer.readUnsignedShort();
+
+    // Word 1.
+    long timestamp = packetBuffer.readUnsignedInt();
+
+    // Word 2.
+    int ssrc = packetBuffer.readInt();
+
+    // CSRC.
+    byte[] csrc;
+    if (csrcCount > 0) {
+      csrc = new byte[csrcCount * CSRC_SIZE];
+      for (int i = 0; i < csrcCount; i++) {
+        packetBuffer.readBytes(csrc, i * CSRC_SIZE, CSRC_SIZE);
+      }
+    } else {
+      csrc = EMPTY;
+    }
+
+    // Everything else will be RTP payload.
+    byte[] payloadData = new byte[packetBuffer.bytesLeft()];
+    packetBuffer.readBytes(payloadData, 0, packetBuffer.bytesLeft());
+
+    Builder builder = new Builder();
+    return builder
+        .setPadding(padding)
+        .setMarker(marker)
+        .setPayloadType(payloadType)
+        .setSequenceNumber(sequenceNumber)
+        .setTimestamp(timestamp)
+        .setSsrc(ssrc)
+        .setCsrc(csrc)
+        .setPayloadData(payloadData)
+        .build();
+  }
+
+  /**
+   * Creates an {@link RtpPacket} from a byte array.
+   *
+   * @param buffer The buffer that contains the RTP packet data.
+   * @param length The length of the RTP packet.
+   * @return The built {@link RtpPacket}.
+   */
+  @Nullable
+  public static RtpPacket parse(byte[] buffer, int length) {
+    return parse(new ParsableByteArray(buffer, length));
+  }
+
+  private RtpPacket(Builder builder) {
+    this.padding = builder.padding;
+    this.extension = false;
+    this.marker = builder.marker;
+    this.payloadType = builder.payloadType;
+    this.sequenceNumber = builder.sequenceNumber;
+    this.timestamp = builder.timestamp;
+    this.ssrc = builder.ssrc;
+    this.csrc = builder.csrc;
+    this.csrcCount = (byte) (this.csrc.length / CSRC_SIZE);
+    this.payloadData = builder.payloadData;
+  }
+
+  /**
+   * Writes the data in an RTP packet to a target buffer.
+   *
+   * <p>The size of the target buffer and the length argument should be big enough so that the
+   * entire RTP packet could fit. That is, if there is not enough space to store the entire RTP
+   * packet, no bytes will be written. The maximum size of an RTP packet is defined as {@link
+   * RtpPacket#MAX_SIZE}.
+   *
+   * @param target A target byte buffer to which the packet data is copied.
+   * @param offset The offset into the target array at which to write.
+   * @param length The maximum number of bytes that can be written.
+   * @return The number of bytes written, or {@link C#LENGTH_UNSET} if there is not enough space to
+   *     write the packet.
+   */
+  public int writeToBuffer(byte[] target, int offset, int length) {
+    int packetLength = MIN_HEADER_SIZE + (CSRC_SIZE * csrcCount) + payloadData.length;
+    if (length < packetLength || target.length - offset < packetLength) {
+      return C.LENGTH_UNSET;
+    }
+
+    ByteBuffer buffer = ByteBuffer.wrap(target, offset, length);
+    byte firstByte =
+        (byte)
+            ((version << 6)
+                | ((padding ? 1 : 0) << 5)
+                | ((extension ? 1 : 0) << 4)
+                | (csrcCount & 0xF));
+    byte secondByte = (byte) (((marker ? 1 : 0) << 7) | (payloadType & 0x7F));
+    buffer
+        .put(firstByte)
+        .put(secondByte)
+        .putShort((short) sequenceNumber)
+        .putInt((int) timestamp)
+        .putInt(ssrc)
+        .put(csrc)
+        .put(payloadData);
+    return packetLength;
+  }
+
+  @Override
+  public boolean equals(@Nullable Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+    RtpPacket rtpPacket = (RtpPacket) o;
+    return payloadType == rtpPacket.payloadType
+        && sequenceNumber == rtpPacket.sequenceNumber
+        && marker == rtpPacket.marker
+        && timestamp == rtpPacket.timestamp
+        && ssrc == rtpPacket.ssrc;
+  }
+
+  @Override
+  public int hashCode() {
+    int result = 17;
+    result = 31 * result + payloadType;
+    result = 31 * result + sequenceNumber;
+    result = 31 * result + (marker ? 1 : 0);
+    result = 31 * result + (int) (timestamp ^ (timestamp >>> 32));
+    result = 31 * result + ssrc;
+    return result;
+  }
+
+  @Override
+  public String toString() {
+    return Util.formatInvariant(
+        "RtpPacket(payloadType=%d, seq=%d, timestamp=%d, ssrc=%x, marker=%b)",
+        payloadType, sequenceNumber, timestamp, ssrc, marker);
+  }
+}

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/rtp/RtpPacketReorderingQueue.java

@@ -0,0 +1,201 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.android.exoplayer2.source.rtsp.rtp;
+
+import static java.lang.Math.abs;
+import static java.lang.Math.max;
+import static java.lang.Math.min;
+
+import androidx.annotation.GuardedBy;
+import androidx.annotation.Nullable;
+import androidx.annotation.VisibleForTesting;
+import com.google.android.exoplayer2.C;
+import java.util.TreeSet;
+
+/**
+ * Orders RTP packets by their sequence numbers to correct the possible alternation in packet
+ * ordering, introduced by UDP transport.
+ */
+/* package */ final class RtpPacketReorderingQueue {
+  /** The maximum sequence number discontinuity allowed without resetting the re-ordering buffer. */
+  @VisibleForTesting /* package */ static final int MAX_SEQUENCE_LEAP_ALLOWED = 1000;
+
+  private static final int MAX_SEQUENCE_NUMBER = RtpPacket.MAX_SEQUENCE_NUMBER;
+
+  // Use set to eliminate duplicating packets.
+  // TODO(b/172331505) Set a upper limit on packetQueue to mitigate out of memory error.
+  @GuardedBy("this")
+  private final TreeSet<RtpPacketContainer> packetQueue;
+
+  @GuardedBy("this")
+  private int lastReceivedSequenceNumber;
+
+  @GuardedBy("this")
+  private int lastDequeuedSequenceNumber;
+
+  @GuardedBy("this")
+  private boolean started;
+
+  /** Creates an instance. */
+  public RtpPacketReorderingQueue() {
+    packetQueue =
+        new TreeSet<>(
+            (packetContainer1, packetContainer2) ->
+                calculateSequenceNumberShift(
+                    packetContainer1.packet.sequenceNumber,
+                    packetContainer2.packet.sequenceNumber));
+
+    reset();
+  }
+
+  public synchronized void reset() {
+    packetQueue.clear();
+    started = false;
+    lastDequeuedSequenceNumber = C.INDEX_UNSET;
+    lastReceivedSequenceNumber = C.INDEX_UNSET;
+  }
+
+  /**
+   * Offer one packet to the reordering queue.
+   *
+   * <p>A packet will not be added to the queue, if a logically preceding packet has already been
+   * dequeued.
+   *
+   * <p>If a packet creates a shift in sequence number that is at least {@link
+   * #MAX_SEQUENCE_LEAP_ALLOWED} compared to the last offered packet, the queue is emptied and then
+   * the packet is added.
+   *
+   * @param packet The packet to add.
+   * @param receivedTimestampMs The timestamp in milliseconds, at which the packet was received.
+   * @return Returns {@code false} if the packet was dropped because it was outside the expected
+   *     range of accepted packets, otherwise {@code true} (on duplicated packets, this method
+   *     returns {@code true}).
+   */
+  public synchronized boolean offer(RtpPacket packet, long receivedTimestampMs) {
+    int packetSequenceNumber = packet.sequenceNumber;
+    if (!started) {
+      reset();
+      lastDequeuedSequenceNumber = prevSequenceNumber(packetSequenceNumber);
+      started = true;
+      addToQueue(new RtpPacketContainer(packet, receivedTimestampMs));
+      return true;
+    }
+
+    int expectedSequenceNumber = nextSequenceNumber(lastReceivedSequenceNumber);
+    // A positive shift means the packet succeeds the last received packet.
+    int sequenceNumberShift =
+        calculateSequenceNumberShift(packetSequenceNumber, expectedSequenceNumber);
+    if (abs(sequenceNumberShift) < MAX_SEQUENCE_LEAP_ALLOWED) {
+      if (calculateSequenceNumberShift(packetSequenceNumber, lastDequeuedSequenceNumber) > 0) {
+        // Add the packet in the queue only if a succeeding packet has not been dequeued already.
+        addToQueue(new RtpPacketContainer(packet, receivedTimestampMs));
+        return true;
+      }
+    } else {
+      // Discard all previous received packets and start subsequent receiving from here.
+      lastDequeuedSequenceNumber = prevSequenceNumber(packetSequenceNumber);
+      packetQueue.clear();
+      addToQueue(new RtpPacketContainer(packet, receivedTimestampMs));
+      return true;
+    }
+    return false;
+  }
+
+  /**
+   * Polls an {@link RtpPacket} from the queue.
+   *
+   * @param cutoffTimestampMs A cutoff timestamp in milliseconds used to determine if the head of
+   *     the queue should be dequeued, even if it's not the next packet in sequence.
+   * @return Returns a packet if the packet at the queue head is the next packet in sequence; or its
+   *     {@link #offer received} timestamp is before {@code cutoffTimestampMs}. Otherwise {@code
+   *     null}.
+   */
+  @Nullable
+  public synchronized RtpPacket poll(long cutoffTimestampMs) {
+    if (packetQueue.isEmpty()) {
+      return null;
+    }
+
+    RtpPacketContainer packetContainer = packetQueue.first();
+    int packetSequenceNumber = packetContainer.packet.sequenceNumber;
+
+    if (packetSequenceNumber == nextSequenceNumber(lastDequeuedSequenceNumber)
+        || cutoffTimestampMs >= packetContainer.receivedTimestampMs) {
+      packetQueue.pollFirst();
+      lastDequeuedSequenceNumber = packetSequenceNumber;
+      return packetContainer.packet;
+    }
+
+    return null;
+  }
+
+  // Internals.
+
+  private synchronized void addToQueue(RtpPacketContainer packet) {
+    lastReceivedSequenceNumber = packet.packet.sequenceNumber;
+    packetQueue.add(packet);
+  }
+
+  private static final class RtpPacketContainer {
+    public final RtpPacket packet;
+    public final long receivedTimestampMs;
+
+    /** Creates an instance. */
+    public RtpPacketContainer(RtpPacket packet, long receivedTimestampMs) {
+      this.packet = packet;
+      this.receivedTimestampMs = receivedTimestampMs;
+    }
+  }
+
+  private static int nextSequenceNumber(int sequenceNumber) {
+    return (sequenceNumber + 1) % MAX_SEQUENCE_NUMBER;
+  }
+
+  private static int prevSequenceNumber(int sequenceNumber) {
+    return sequenceNumber == 0
+        ? MAX_SEQUENCE_NUMBER - 1
+        : (sequenceNumber - 1) % MAX_SEQUENCE_NUMBER;
+  }
+
+  /**
+   * Calculates the sequence number shift, accounting for wrapping around.
+   *
+   * @param sequenceNumber The currently received sequence number.
+   * @param previousSequenceNumber The previous sequence number to compare against.
+   * @return The shift in the sequence numbers. A positive shift indicates that {@code
+   *     sequenceNumber} is logically after {@code previousSequenceNumber}, whereas a negative shift
+   *     means that {@code sequenceNumber} is logically before {@code previousSequenceNumber}.
+   */
+  private static int calculateSequenceNumberShift(int sequenceNumber, int previousSequenceNumber) {
+    int sequenceShift = sequenceNumber - previousSequenceNumber;
+    if (abs(sequenceShift) > MAX_SEQUENCE_LEAP_ALLOWED) {
+      int shift =
+          min(sequenceNumber, previousSequenceNumber)
+              - max(sequenceNumber, previousSequenceNumber)
+              + MAX_SEQUENCE_NUMBER;
+      // Check whether this is actually an wrap-over. For example, it is a wrap around if receiving
+      // 65500 (prevSequenceNumber) after 1 (sequenceNumber); but it is not when prevSequenceNumber
+      // is 30000.
+      if (shift < MAX_SEQUENCE_LEAP_ALLOWED) {
+        return sequenceNumber < previousSequenceNumber
+            ? /* receiving 65000 (curr) then 1 (prev) */ shift
+            : /* receiving 1 (curr) then 65500 (prev) */ -shift;
+      }
+    }
+    return sequenceShift;
+  }
+}

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/rtp/RtpPayloadFormat.java

@@ -0,0 +1,127 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.source.rtsp.rtp;
+
+import androidx.annotation.Nullable;
+import com.google.android.exoplayer2.Format;
+import com.google.android.exoplayer2.source.rtsp.sdp.MediaDescription;
+import com.google.android.exoplayer2.source.rtsp.sdp.SessionDescription;
+import com.google.android.exoplayer2.util.MimeTypes;
+import com.google.common.base.Ascii;
+import com.google.common.collect.ImmutableMap;
+import java.util.Map;
+
+/**
+ * Represents the payload format used in RTP.
+ *
+ * <p>In RTSP playback, the format information is always present in the {@link SessionDescription}
+ * enclosed in the response of a DESCRIBE request. Within each track's {@link MediaDescription}, it
+ * is the attributes FMTP and RTPMAP that allows us to recreate the media format.
+ *
+ * <p>This class wraps around the {@link Format} class, in addition to the instance fields that are
+ * specific to RTP.
+ */
+public final class RtpPayloadFormat {
+
+  private static final String RTP_MEDIA_AC3 = "AC3";
+  private static final String RTP_MEDIA_MPEG4_GENERIC = "MPEG4-GENERIC";
+  private static final String RTP_MEDIA_H264 = "H264";
+
+  /** Returns whether the format of a {@link MediaDescription} is supported. */
+  public static boolean isFormatSupported(MediaDescription mediaDescription) {
+    switch (Ascii.toUpperCase(mediaDescription.rtpMapAttribute.mediaEncoding)) {
+      case RTP_MEDIA_AC3:
+      case RTP_MEDIA_H264:
+      case RTP_MEDIA_MPEG4_GENERIC:
+        return true;
+      default:
+        return false;
+    }
+  }
+
+  /**
+   * Gets the MIME type that is associated with the RTP media type.
+   *
+   * <p>For instance, RTP media type "H264" maps to {@link MimeTypes#VIDEO_H264}.
+   *
+   * @throws IllegalArgumentException When the media type is not supported/recognized.
+   */
+  public static String getMimeTypeFromRtpMediaType(String mediaType) {
+    switch (Ascii.toUpperCase(mediaType)) {
+      case RTP_MEDIA_AC3:
+        return MimeTypes.AUDIO_AC3;
+      case RTP_MEDIA_H264:
+        return MimeTypes.VIDEO_H264;
+      case RTP_MEDIA_MPEG4_GENERIC:
+        return MimeTypes.AUDIO_AAC;
+      default:
+        throw new IllegalArgumentException(mediaType);
+    }
+  }
+
+  /** The payload type associated with this format. */
+  public final int rtpPayloadType;
+  /** The clock rate in Hertz, associated with the format. */
+  public final int clockRate;
+  /** The {@link Format} of this RTP payload. */
+  public final Format format;
+  /** The format parameters, mapped from the SDP FMTP attribute (RFC2327 Page 22). */
+  public final ImmutableMap<String, String> fmtpParameters;
+
+  /**
+   * Creates a new instance.
+   *
+   * @param format The associated {@link Format media format}.
+   * @param rtpPayloadType The assigned RTP payload type, from the RTPMAP attribute in {@link
+   *     MediaDescription}.
+   * @param clockRate The associated clock rate in hertz.
+   * @param fmtpParameters The format parameters, from the SDP FMTP attribute (RFC2327 Page 22),
+   *     empty if unset. The keys and values are specified in the RFCs for specific formats. For
+   *     instance, RFC3640 Section 4.1 defines keys like profile-level-id and config.
+   */
+  public RtpPayloadFormat(
+      Format format, int rtpPayloadType, int clockRate, Map<String, String> fmtpParameters) {
+    this.rtpPayloadType = rtpPayloadType;
+    this.clockRate = clockRate;
+    this.format = format;
+    this.fmtpParameters = ImmutableMap.copyOf(fmtpParameters);
+  }
+
+  @Override
+  public boolean equals(@Nullable Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+    RtpPayloadFormat that = (RtpPayloadFormat) o;
+    return rtpPayloadType == that.rtpPayloadType
+        && clockRate == that.clockRate
+        && format.equals(that.format)
+        && fmtpParameters.equals(that.fmtpParameters);
+  }
+
+  @Override
+  public int hashCode() {
+    int result = 7;
+    result = 31 * result + rtpPayloadType;
+    result = 31 * result + clockRate;
+    result = 31 * result + format.hashCode();
+    result = 31 * result + fmtpParameters.hashCode();
+    return result;
+  }
+}

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/rtp/package-info.java

@@ -0,0 +1,19 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+@NonNullApi
+package com.google.android.exoplayer2.source.rtsp.rtp;
+
+import com.google.android.exoplayer2.util.NonNullApi;

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/rtp/reader/DefaultRtpPayloadReaderFactory.java

@@ -0,0 +1,43 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.android.exoplayer2.source.rtsp.rtp.reader;
+
+import static com.google.android.exoplayer2.util.Assertions.checkNotNull;
+
+import androidx.annotation.Nullable;
+import com.google.android.exoplayer2.source.rtsp.rtp.RtpPayloadFormat;
+import com.google.android.exoplayer2.util.MimeTypes;
+
+/** Default {@link RtpPayloadReader.Factory} implementation. */
+public final class DefaultRtpPayloadReaderFactory implements RtpPayloadReader.Factory {
+
+  @Override
+  @Nullable
+  public RtpPayloadReader createPayloadReader(RtpPayloadFormat payloadFormat) {
+    switch (checkNotNull(payloadFormat.format.sampleMimeType)) {
+      case MimeTypes.AUDIO_AC3:
+        return new RtpAc3Reader(payloadFormat);
+      case MimeTypes.AUDIO_AAC:
+        return new RtpAacReader(payloadFormat);
+      case MimeTypes.VIDEO_H264:
+        return new RtpH264Reader(payloadFormat);
+      default:
+        // No supported reader, returning null.
+    }
+    return null;
+  }
+}

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/rtp/reader/RtpAacReader.java

@@ -0,0 +1,166 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.source.rtsp.rtp.reader;
+
+import static com.google.android.exoplayer2.util.Assertions.checkNotNull;
+
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.extractor.ExtractorOutput;
+import com.google.android.exoplayer2.extractor.TrackOutput;
+import com.google.android.exoplayer2.source.rtsp.rtp.RtpPayloadFormat;
+import com.google.android.exoplayer2.util.ParsableBitArray;
+import com.google.android.exoplayer2.util.ParsableByteArray;
+import com.google.android.exoplayer2.util.Util;
+import com.google.common.base.Ascii;
+import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
+
+/**
+ * Parses a AAC byte stream carried on RTP packets and extracts individual samples. Interleaving
+ * mode is not supported.
+ */
+/* package */ final class RtpAacReader implements RtpPayloadReader {
+
+  /** AAC low bit rate mode, RFC3640 Section 3.3.5. */
+  private static final String AAC_LOW_BITRATE_MODE = "AAC-lbr";
+  /** AAC high bit rate mode, RFC3640 Section 3.3.6. */
+  private static final String AAC_HIGH_BITRATE_MODE = "AAC-hbr";
+
+  private static final String TAG = "RtpAacReader";
+
+  private final RtpPayloadFormat payloadFormat;
+  private final ParsableBitArray auHeaderScratchBit;
+  private final int sampleRate;
+  private final int auSizeFieldBitSize;
+  private final int auIndexFieldBitSize;
+  private final int numBitsInAuHeader;
+
+  private long firstReceivedTimestamp;
+  private @MonotonicNonNull TrackOutput trackOutput;
+  private long startTimeOffsetUs;
+
+  public RtpAacReader(RtpPayloadFormat payloadFormat) {
+    this.payloadFormat = payloadFormat;
+    this.auHeaderScratchBit = new ParsableBitArray();
+    this.sampleRate = this.payloadFormat.clockRate;
+
+    // mode attribute is mandatory. See RFC3640 Section 4.1.
+    String mode = checkNotNull(payloadFormat.fmtpParameters.get("mode"));
+    if (Ascii.equalsIgnoreCase(mode, AAC_HIGH_BITRATE_MODE)) {
+      auSizeFieldBitSize = 13;
+      auIndexFieldBitSize = 3;
+    } else if (Ascii.equalsIgnoreCase(mode, AAC_LOW_BITRATE_MODE)) {
+      auSizeFieldBitSize = 6;
+      auIndexFieldBitSize = 2;
+    } else {
+      throw new UnsupportedOperationException("AAC mode not supported");
+    }
+    // TODO(b/172331505) Add support for other AU-Header fields, like CTS-flag, CTS-delta, etc.
+    numBitsInAuHeader = auIndexFieldBitSize + auSizeFieldBitSize;
+  }
+
+  // RtpPayloadReader implementation.
+
+  @Override
+  public void createTracks(ExtractorOutput extractorOutput, int trackId) {
+    trackOutput = extractorOutput.track(trackId, C.TRACK_TYPE_AUDIO);
+    trackOutput.format(payloadFormat.format);
+  }
+
+  @Override
+  public void onReceivingFirstPacket(long timestamp, int sequenceNumber) {
+    this.firstReceivedTimestamp = timestamp;
+  }
+
+  @Override
+  public void consume(
+      ParsableByteArray data, long timestamp, int sequenceNumber, boolean isFrameBoundary) {
+    /*
+    AAC as RTP payload (RFC3640):
+      +---------+-----------+-----------+---------------+
+      | RTP     | AU Header | Auxiliary | Access Unit   |
+      | Header  | Section   | Section   | Data Section  |
+      +---------+-----------+-----------+---------------+
+                <----------RTP Packet Payload----------->
+
+    Access Unit(AU) Header section
+      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- .. -+-+-+-+-+-+-+-+-+-+
+      |AU-headers-length|AU-header|AU-header|      |AU-header|padding|
+      |in bits          |   (1)   |   (2)   |      |   (n)   | bits  |
+      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- .. -+-+-+-+-+-+-+-+-+-+
+
+    The 16-bit AU-headers-length is mandatory in the AAC-lbr and AAC-hbr modes that we support.
+    */
+    checkNotNull(trackOutput);
+    // Reads AU-header-length that specifies the length in bits of the immediately following
+    // AU-headers, excluding the padding.
+    int auHeadersBitLength = data.readShort();
+    int auHeaderCount = auHeadersBitLength / numBitsInAuHeader;
+    long sampleTimeUs =
+        toSampleTimeUs(startTimeOffsetUs, timestamp, firstReceivedTimestamp, sampleRate);
+
+    // Points to the start of the AU-headers (right past the AU-headers-length).
+    auHeaderScratchBit.reset(data);
+    if (auHeaderCount == 1) {
+      // Reads the first AU-Header that contains AU-Size and AU-Index/AU-Index-delta.
+      int auSize = auHeaderScratchBit.readBits(auSizeFieldBitSize);
+      auHeaderScratchBit.skipBits(auIndexFieldBitSize);
+
+      // Outputs all the received data, whether fragmented or not.
+      trackOutput.sampleData(data, data.bytesLeft());
+      if (isFrameBoundary) {
+        outputSampleMetadata(trackOutput, sampleTimeUs, auSize);
+      }
+    } else {
+      // Skips the AU-headers section to the data section, accounts for the possible padding bits.
+      data.skipBytes((auHeadersBitLength + 7) / 8);
+      for (int i = 0; i < auHeaderCount; i++) {
+        int auSize = auHeaderScratchBit.readBits(auSizeFieldBitSize);
+        auHeaderScratchBit.skipBits(auIndexFieldBitSize);
+
+        trackOutput.sampleData(data, auSize);
+        outputSampleMetadata(trackOutput, sampleTimeUs, auSize);
+        // The sample time of the  of the i-th AU (RFC3640 Page 17):
+        // (timestamp-of-the-first-AU) + i * (access-unit-duration)
+        sampleTimeUs +=
+            Util.scaleLargeTimestamp(
+                auHeaderCount, /* multiplier= */ C.MICROS_PER_SECOND, /* divisor= */ sampleRate);
+      }
+    }
+  }
+
+  @Override
+  public void seek(long nextRtpTimestamp, long timeUs) {
+    firstReceivedTimestamp = nextRtpTimestamp;
+    startTimeOffsetUs = timeUs;
+  }
+
+  // Internal methods.
+
+  private static void outputSampleMetadata(TrackOutput trackOutput, long sampleTimeUs, int size) {
+    trackOutput.sampleMetadata(
+        sampleTimeUs, C.BUFFER_FLAG_KEY_FRAME, size, /* offset= */ 0, /* encryptionData= */ null);
+  }
+
+  /** Returns the correct sample time from RTP timestamp, accounting for the AAC sampling rate. */
+  private static long toSampleTimeUs(
+      long startTimeOffsetUs, long rtpTimestamp, long firstReceivedRtpTimestamp, int sampleRate) {
+    return startTimeOffsetUs
+        + Util.scaleLargeTimestamp(
+            rtpTimestamp - firstReceivedRtpTimestamp,
+            /* multiplier= */ C.MICROS_PER_SECOND,
+            /* divisor= */ sampleRate);
+  }
+}

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/rtp/reader/RtpAc3Reader.java

@@ -0,0 +1,219 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.source.rtsp.rtp.reader;
+
+import static com.google.android.exoplayer2.util.Assertions.checkNotNull;
+import static com.google.android.exoplayer2.util.Assertions.checkState;
+import static com.google.android.exoplayer2.util.Util.castNonNull;
+
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.audio.Ac3Util;
+import com.google.android.exoplayer2.extractor.ExtractorOutput;
+import com.google.android.exoplayer2.extractor.TrackOutput;
+import com.google.android.exoplayer2.source.rtsp.rtp.RtpPayloadFormat;
+import com.google.android.exoplayer2.util.ParsableBitArray;
+import com.google.android.exoplayer2.util.ParsableByteArray;
+import com.google.android.exoplayer2.util.Util;
+import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
+
+/** Parses an AC3 byte stream carried on RTP packets, and extracts AC3 frames. */
+public final class RtpAc3Reader implements RtpPayloadReader {
+
+  /** AC3 frame types defined in RFC4184 Section 4.1.1. */
+  private static final int AC3_FRAME_TYPE_COMPLETE_FRAME = 0;
+  /** Initial fragment of frame which includes the first 5/8ths of the frame. */
+  private static final int AC3_FRAME_TYPE_INITIAL_FRAGMENT_A = 1;
+  /** Initial fragment of frame which does not include the first 5/8ths of the frame. */
+  private static final int AC3_FRAME_TYPE_INITIAL_FRAGMENT_B = 2;
+
+  private static final int AC3_FRAME_TYPE_NON_INITIAL_FRAGMENT = 3;
+
+  /** AC3 payload header size in bytes. */
+  private static final int AC3_PAYLOAD_HEADER_SIZE = 2;
+
+  private final RtpPayloadFormat payloadFormat;
+  private final ParsableBitArray scratchBitBuffer;
+
+  private @MonotonicNonNull TrackOutput trackOutput;
+  private int numBytesPendingMetadataOutput;
+  private long firstReceivedTimestamp;
+  private long sampleTimeUsOfFramePendingMetadataOutput;
+  private long startTimeOffsetUs;
+
+  public RtpAc3Reader(RtpPayloadFormat payloadFormat) {
+    this.payloadFormat = payloadFormat;
+    scratchBitBuffer = new ParsableBitArray();
+    firstReceivedTimestamp = C.TIME_UNSET;
+  }
+
+  @Override
+  public void createTracks(ExtractorOutput extractorOutput, int trackId) {
+    trackOutput = extractorOutput.track(trackId, C.TRACK_TYPE_AUDIO);
+    trackOutput.format(payloadFormat.format);
+  }
+
+  @Override
+  public void onReceivingFirstPacket(long timestamp, int sequenceNumber) {
+    checkState(firstReceivedTimestamp == C.TIME_UNSET);
+    firstReceivedTimestamp = timestamp;
+  }
+
+  @Override
+  public void consume(
+      ParsableByteArray data, long timestamp, int sequenceNumber, boolean isFrameBoundary) {
+    /*
+    AC-3 payload as an RTP payload (RFC4184).
+      +-+-+-+-+-+-+-+-+-+-+-+-+-+- .. +-+-+-+-+-+-+-+
+      | Payload | Frame | Frame |     | Frame |
+      | Header  |  (1)  |  (2)  |     |  (n)  |
+      +-+-+-+-+-+-+-+-+-+-+-+-+-+- .. +-+-+-+-+-+-+-+
+
+    The payload header:
+       0                   1
+       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+      |    MBZ    | FT|       NF      |
+      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+      FT: frame type.
+      NF: number of frames/fragments.
+     */
+    int frameType = data.readUnsignedByte() & 0x3;
+    int numOfFrames = data.readUnsignedByte() & 0xFF;
+
+    long sampleTimeUs =
+        toSampleTimeUs(
+            startTimeOffsetUs, timestamp, firstReceivedTimestamp, payloadFormat.clockRate);
+
+    switch (frameType) {
+      case AC3_FRAME_TYPE_COMPLETE_FRAME:
+        maybeOutputSampleMetadata();
+        if (numOfFrames == 1) {
+          // Single AC3 frame in one RTP packet.
+          processSingleFramePacket(data, sampleTimeUs);
+        } else {
+          // Multiple AC3 frames in one RTP packet.
+          processMultiFramePacket(data, numOfFrames, sampleTimeUs);
+        }
+        break;
+
+      case AC3_FRAME_TYPE_INITIAL_FRAGMENT_A:
+      case AC3_FRAME_TYPE_INITIAL_FRAGMENT_B:
+        maybeOutputSampleMetadata();
+        // Falls through.
+      case AC3_FRAME_TYPE_NON_INITIAL_FRAGMENT:
+        // The content of an AC3 frame is split into multiple RTP packets.
+        processFragmentedPacket(data, isFrameBoundary, frameType, sampleTimeUs);
+        break;
+
+      default:
+        throw new IllegalArgumentException(String.valueOf(frameType));
+    }
+  }
+
+  @Override
+  public void seek(long nextRtpTimestamp, long timeUs) {
+    firstReceivedTimestamp = nextRtpTimestamp;
+    startTimeOffsetUs = timeUs;
+  }
+
+  private void processSingleFramePacket(ParsableByteArray data, long sampleTimeUs) {
+    int frameSize = data.bytesLeft();
+    checkNotNull(trackOutput).sampleData(data, frameSize);
+    castNonNull(trackOutput)
+        .sampleMetadata(
+            /* timeUs= */ sampleTimeUs,
+            /* flags= */ C.BUFFER_FLAG_KEY_FRAME,
+            /* size= */ frameSize,
+            /* offset= */ 0,
+            /* encryptionData= */ null);
+  }
+
+  private void processMultiFramePacket(ParsableByteArray data, int numOfFrames, long sampleTimeUs) {
+    // The size of each frame must be obtained by reading AC3 sync frame.
+    scratchBitBuffer.reset(data.getData());
+    // Move the read location after the AC3 payload header.
+    scratchBitBuffer.skipBytes(AC3_PAYLOAD_HEADER_SIZE);
+
+    for (int i = 0; i < numOfFrames; i++) {
+      Ac3Util.SyncFrameInfo frameInfo = Ac3Util.parseAc3SyncframeInfo(scratchBitBuffer);
+
+      checkNotNull(trackOutput).sampleData(data, frameInfo.frameSize);
+      castNonNull(trackOutput)
+          .sampleMetadata(
+              /* timeUs= */ sampleTimeUs,
+              /* flags= */ C.BUFFER_FLAG_KEY_FRAME,
+              /* size= */ frameInfo.frameSize,
+              /* offset= */ 0,
+              /* encryptionData= */ null);
+
+      sampleTimeUs += (frameInfo.sampleCount / frameInfo.sampleRate) * C.MICROS_PER_SECOND;
+      // Advance the position by the number of bytes read.
+      scratchBitBuffer.skipBytes(frameInfo.frameSize);
+    }
+  }
+
+  private void processFragmentedPacket(
+      ParsableByteArray data, boolean isFrameBoundary, int frameType, long sampleTimeUs) {
+    int bytesToWrite = data.bytesLeft();
+    checkNotNull(trackOutput).sampleData(data, bytesToWrite);
+    numBytesPendingMetadataOutput += bytesToWrite;
+    sampleTimeUsOfFramePendingMetadataOutput = sampleTimeUs;
+
+    if (isFrameBoundary && frameType == AC3_FRAME_TYPE_NON_INITIAL_FRAGMENT) {
+      // Last RTP packet in the series of fragmentation packets.
+      outputSampleMetadataForFragmentedPackets();
+    }
+  }
+
+  /**
+   * Checks and outputs sample metadata, if the last packet of a series of fragmented packets is
+   * lost.
+   *
+   * <p>Call this method only when receiving an initial packet, i.e. on packets with type
+   *
+   * <ul>
+   *   <li>{@link #AC3_FRAME_TYPE_COMPLETE_FRAME},
+   *   <li>{@link #AC3_FRAME_TYPE_INITIAL_FRAGMENT_A}, or
+   *   <li>{@link #AC3_FRAME_TYPE_INITIAL_FRAGMENT_B}.
+   * </ul>
+   */
+  private void maybeOutputSampleMetadata() {
+    if (numBytesPendingMetadataOutput > 0) {
+      outputSampleMetadataForFragmentedPackets();
+    }
+  }
+
+  private void outputSampleMetadataForFragmentedPackets() {
+    castNonNull(trackOutput)
+        .sampleMetadata(
+            /* timeUs= */ sampleTimeUsOfFramePendingMetadataOutput,
+            /* flags= */ C.BUFFER_FLAG_KEY_FRAME,
+            /* size= */ numBytesPendingMetadataOutput,
+            /* offset= */ 0,
+            /* encryptionData= */ null);
+    numBytesPendingMetadataOutput = 0;
+  }
+
+  /** Returns the correct sample time from RTP timestamp, accounting for the AC3 sampling rate. */
+  private static long toSampleTimeUs(
+      long startTimeOffsetUs, long rtpTimestamp, long firstReceivedRtpTimestamp, int sampleRate) {
+    return startTimeOffsetUs
+        + Util.scaleLargeTimestamp(
+            rtpTimestamp - firstReceivedRtpTimestamp,
+            /* multiplier= */ C.MICROS_PER_SECOND,
+            /* divisor= */ sampleRate);
+  }
+}

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/rtp/reader/RtpH264Reader.java

@@ -0,0 +1,307 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.source.rtsp.rtp.reader;
+
+import static com.google.android.exoplayer2.util.Assertions.checkStateNotNull;
+import static com.google.android.exoplayer2.util.Util.castNonNull;
+
+import android.util.Log;
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.ParserException;
+import com.google.android.exoplayer2.extractor.ExtractorOutput;
+import com.google.android.exoplayer2.extractor.TrackOutput;
+import com.google.android.exoplayer2.source.rtsp.rtp.RtpPacket;
+import com.google.android.exoplayer2.source.rtsp.rtp.RtpPayloadFormat;
+import com.google.android.exoplayer2.util.NalUnitUtil;
+import com.google.android.exoplayer2.util.ParsableByteArray;
+import com.google.android.exoplayer2.util.Util;
+import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
+import org.checkerframework.checker.nullness.qual.RequiresNonNull;
+
+/** Parses an H264 byte stream carried on RTP packets, and extracts H264 Access Units. */
+/* package */ final class RtpH264Reader implements RtpPayloadReader {
+  private static final String TAG = "RtpH264Reader";
+
+  // TODO(b/172331505) Move NAL related constants to NalUnitUtil.
+  private static final ParsableByteArray NAL_START_CODE =
+      new ParsableByteArray(NalUnitUtil.NAL_START_CODE);
+  private static final int NAL_START_CODE_LENGTH = NalUnitUtil.NAL_START_CODE.length;
+  private static final long MEDIA_CLOCK_FREQUENCY = 90_000;
+
+  /** Offset of payload data within a FU type A payload. */
+  private static final int FU_PAYLOAD_OFFSET = 2;
+
+  /** Single Time Aggregation Packet type A. */
+  private static final int RTP_PACKET_TYPE_STAP_A = 24;
+  /** Fragmentation Unit type A. */
+  private static final int RTP_PACKET_TYPE_FU_A = 28;
+
+  /** IDR NAL unit type. */
+  private static final int NAL_UNIT_TYPE_IDR = 5;
+
+  /** Scratch for Fragmentation Unit RTP packets. */
+  private final ParsableByteArray fuScratchBuffer;
+
+  private final RtpPayloadFormat payloadFormat;
+
+  private @MonotonicNonNull TrackOutput trackOutput;
+  @C.BufferFlags private int bufferFlags;
+
+  private long firstReceivedTimestamp;
+  private int previousSequenceNumber;
+  /** The combined size of a sample that is fragmented into multiple RTP packets. */
+  private int fragmentedSampleSizeBytes;
+
+  private long startTimeOffsetUs;
+
+  /** Creates an instance. */
+  public RtpH264Reader(RtpPayloadFormat payloadFormat) {
+    this.payloadFormat = payloadFormat;
+    fuScratchBuffer = new ParsableByteArray();
+    firstReceivedTimestamp = C.TIME_UNSET;
+    previousSequenceNumber = C.INDEX_UNSET;
+  }
+
+  @Override
+  public void createTracks(ExtractorOutput extractorOutput, int trackId) {
+    trackOutput = extractorOutput.track(trackId, C.TRACK_TYPE_VIDEO);
+
+    castNonNull(trackOutput).format(payloadFormat.format);
+  }
+
+  @Override
+  public void onReceivingFirstPacket(long timestamp, int sequenceNumber) {}
+
+  @Override
+  public void consume(
+      ParsableByteArray data, long timestamp, int sequenceNumber, boolean isAuBoundary)
+      throws ParserException {
+
+    int rtpH264PacketMode;
+    try {
+      // RFC6184 Section 5.6, 5.7 and 5.8.
+      rtpH264PacketMode = data.getData()[0] & 0x1F;
+    } catch (IndexOutOfBoundsException e) {
+      throw new ParserException(e);
+    }
+
+    checkStateNotNull(trackOutput);
+    if (rtpH264PacketMode > 0 && rtpH264PacketMode < 24) {
+      processSingleNalUnitPacket(data);
+    } else if (rtpH264PacketMode == RTP_PACKET_TYPE_STAP_A) {
+      processSingleTimeAggregationPacket(data);
+    } else if (rtpH264PacketMode == RTP_PACKET_TYPE_FU_A) {
+      processFragmentationUnitPacket(data, sequenceNumber);
+    } else {
+      throw new ParserException(
+          String.format("RTP H264 packetization mode [%d] not supported.", rtpH264PacketMode));
+    }
+
+    if (isAuBoundary) {
+      if (firstReceivedTimestamp == C.TIME_UNSET) {
+        firstReceivedTimestamp = timestamp;
+      }
+
+      long timeUs = toSampleUs(startTimeOffsetUs, timestamp, firstReceivedTimestamp);
+      trackOutput.sampleMetadata(
+          timeUs,
+          bufferFlags,
+          fragmentedSampleSizeBytes,
+          /* offset= */ 0,
+          /* encryptionData= */ null);
+      fragmentedSampleSizeBytes = 0;
+    }
+
+    previousSequenceNumber = sequenceNumber;
+  }
+
+  @Override
+  public void seek(long nextRtpTimestamp, long timeUs) {
+    firstReceivedTimestamp = nextRtpTimestamp;
+    fragmentedSampleSizeBytes = 0;
+    startTimeOffsetUs = timeUs;
+  }
+
+  // Internal methods.
+
+  /**
+   * Processes Single NAL Unit packet (RFC6184 Section 5.6).
+   *
+   * <p>Outputs the single NAL Unit (with start code prepended) to {@link #trackOutput}. Sets {@link
+   * #bufferFlags} and {@link #fragmentedSampleSizeBytes} accordingly.
+   */
+  @RequiresNonNull("trackOutput")
+  private void processSingleNalUnitPacket(ParsableByteArray data) {
+    // Example of a Single Nal Unit packet
+    //    0                   1                   2                   3
+    //    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+    //    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    //    |F|NRI|  Type   |                                               |
+    //    +-+-+-+-+-+-+-+-+                                               |
+    //    |                                                               |
+    //    |               Bytes 2..n of a single NAL unit                 |
+    //    |                                                               |
+    //    |                               +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    //    |                               :...OPTIONAL RTP padding        |
+    //    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+    int numBytesInData = data.bytesLeft();
+    fragmentedSampleSizeBytes += writeStartCode(trackOutput);
+    trackOutput.sampleData(data, numBytesInData);
+    fragmentedSampleSizeBytes += numBytesInData;
+
+    int nalHeaderType = data.getData()[0] & 0x1F;
+    bufferFlags = getBufferFlagsFromNalType(nalHeaderType);
+  }
+
+  /**
+   * Processes STAP Type A packet (RFC6184 Section 5.7).
+   *
+   * <p>Outputs the received aggregation units (with start code prepended) to {@link #trackOutput}.
+   * Sets {@link #bufferFlags} and {@link #fragmentedSampleSizeBytes} accordingly.
+   */
+  @RequiresNonNull("trackOutput")
+  private void processSingleTimeAggregationPacket(ParsableByteArray data) {
+    //  Example of an STAP-A packet.
+    //      0                   1                   2                   3
+    //     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+    //    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    //    |                          RTP Header                           |
+    //    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    //    |STAP-A NAL HDR |         NALU 1 Size           | NALU 1 HDR    |
+    //    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    //    |                         NALU 1 Data                           |
+    //    :                                                               :
+    //    +               +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    //    |               | NALU 2 Size                   | NALU 2 HDR    |
+    //    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    //    |                         NALU 2 Data                           |
+    //    :                                                               :
+    //    |                               +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    //    |                               :...OPTIONAL RTP padding        |
+    //    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+    // Skips STAP-A NAL HDR that has the NAL format |F|NRI|Type|, but with Type replaced by the
+    // STAP-A type id (RTP_PACKET_TYPE_STAP_A).
+    data.readUnsignedByte();
+
+    // Gets all NAL units until the remaining bytes are only enough to store an RTP padding.
+    int nalUnitLength;
+    while (data.bytesLeft() > 4) {
+      nalUnitLength = data.readUnsignedShort();
+      fragmentedSampleSizeBytes += writeStartCode(trackOutput);
+      trackOutput.sampleData(data, nalUnitLength);
+      fragmentedSampleSizeBytes += nalUnitLength;
+    }
+
+    // Treat Aggregated NAL units as non key frames.
+    // TODO(internal b/172331505) examine whether STAP mode carries keyframes.
+    bufferFlags = 0;
+  }
+
+  /**
+   * Processes Fragmentation Unit Type A packet (RFC6184 Section 5.8).
+   *
+   * <p>This method will be invoked multiple times to receive a single frame that is broken down
+   * into a series of fragmentation units in multiple RTP packets.
+   *
+   * <p>Outputs the received fragmentation units (with start code prepended) to {@link
+   * #trackOutput}. Sets {@link #bufferFlags} and {@link #fragmentedSampleSizeBytes} accordingly.
+   */
+  @RequiresNonNull("trackOutput")
+  private void processFragmentationUnitPacket(ParsableByteArray data, int packetSequenceNumber) {
+    //  FU-A mode packet layout.
+    //   0                   1                   2                   3
+    //   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+    //  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    //  | FU indicator  |   FU header   |                               |
+    //  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                               |
+    //  |                                                               |
+    //  |                         FU payload                            |
+    //  |                                                               |
+    //  |                               +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    //  |                               :...OPTIONAL RTP padding        |
+    //  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    //
+    //     FU Indicator     FU Header
+    //   0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+    //  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    //  |F|NRI|  Type   |S|E|R|  Type   |
+    //  +---------------+---------------+
+    //  Indicator: Upper 3 bits are the same as NALU header, Type = 28 (FU-A type).
+    //  Header: Start/End/Reserved/Type. Type is same as NALU type.
+    int fuIndicator = data.getData()[0];
+    int fuHeader = data.getData()[1];
+    int nalHeader = (fuIndicator & 0xE0) | (fuHeader & 0x1F);
+    boolean isFirstFuPacket = (fuHeader & 0x80) > 0;
+    boolean isLastFuPacket = (fuHeader & 0x40) > 0;
+
+    if (isFirstFuPacket) {
+      // Prepends starter code.
+      fragmentedSampleSizeBytes += writeStartCode(trackOutput);
+
+      // The bytes needed is 1 (NALU header) + payload size. The original data array has size 2 (FU
+      // indicator/header) + payload size. Thus setting the correct header and set position to 1.
+      data.getData()[1] = (byte) nalHeader;
+      fuScratchBuffer.reset(data.getData());
+      fuScratchBuffer.setPosition(1);
+    } else {
+      // Check that this packet is in the sequence of the previous packet.
+      int expectedSequenceNumber = (previousSequenceNumber + 1) % RtpPacket.MAX_SEQUENCE_NUMBER;
+      if (packetSequenceNumber != expectedSequenceNumber) {
+        Log.w(
+            TAG,
+            Util.formatInvariant(
+                "Received RTP packet with unexpected sequence number. Expected: %d; received: %d."
+                    + " Dropping packet.",
+                expectedSequenceNumber, packetSequenceNumber));
+        return;
+      }
+
+      // Setting position to ignore FU indicator and header.
+      fuScratchBuffer.reset(data.getData());
+      fuScratchBuffer.setPosition(FU_PAYLOAD_OFFSET);
+    }
+
+    int fragmentSize = fuScratchBuffer.bytesLeft();
+    trackOutput.sampleData(fuScratchBuffer, fragmentSize);
+    fragmentedSampleSizeBytes += fragmentSize;
+
+    if (isLastFuPacket) {
+      bufferFlags = getBufferFlagsFromNalType(nalHeader & 0x1F);
+    }
+  }
+
+  private static long toSampleUs(
+      long startTimeOffsetUs, long rtpTimestamp, long firstReceivedRtpTimestamp) {
+    return startTimeOffsetUs
+        + Util.scaleLargeTimestamp(
+            (rtpTimestamp - firstReceivedRtpTimestamp),
+            /* multiplier= */ C.MICROS_PER_SECOND,
+            /* divisor= */ MEDIA_CLOCK_FREQUENCY);
+  }
+
+  private static int writeStartCode(TrackOutput trackOutput) {
+    trackOutput.sampleData(NAL_START_CODE, NAL_START_CODE_LENGTH);
+    NAL_START_CODE.setPosition(/* position= */ 0);
+    return NAL_START_CODE_LENGTH;
+  }
+
+  @C.BufferFlags
+  private static int getBufferFlagsFromNalType(int nalType) {
+    return nalType == NAL_UNIT_TYPE_IDR ? C.BUFFER_FLAG_KEY_FRAME : 0;
+  }
+}

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/rtp/reader/RtpPayloadReader.java

@@ -0,0 +1,85 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.android.exoplayer2.source.rtsp.rtp.reader;
+
+import com.google.android.exoplayer2.ParserException;
+import com.google.android.exoplayer2.extractor.ExtractorOutput;
+import com.google.android.exoplayer2.source.rtsp.rtp.RtpPayloadFormat;
+import com.google.android.exoplayer2.util.ParsableByteArray;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+/** Extracts media samples from the payload of received RTP packets. */
+public interface RtpPayloadReader {
+
+  /** Factory of {@link RtpPayloadReader} instances. */
+  interface Factory {
+
+    /**
+     * Returns a {@link RtpPayloadReader} for a given {@link RtpPayloadFormat}.
+     *
+     * @param payloadFormat The {@link RtpPayloadFormat} of the RTP stream.
+     * @return A {@link RtpPayloadReader} for the packet stream, or {@code null} if the stream
+     *     format is not supported.
+     */
+    @Nullable
+    RtpPayloadReader createPayloadReader(RtpPayloadFormat payloadFormat);
+  }
+
+  /**
+   * Initializes the reader by providing its output and track id.
+   *
+   * @param extractorOutput The {@link ExtractorOutput} instance that receives the extracted data.
+   * @param trackId The track identifier to set on the format.
+   */
+  void createTracks(ExtractorOutput extractorOutput, int trackId);
+
+  /**
+   * This method should be called on reading the first packet in a stream of incoming packets.
+   *
+   * @param timestamp The timestamp associated with the first received RTP packet. This number has
+   *     no unit, the duration conveyed by it depends on the frequency of the media that the RTP
+   *     packet is carrying.
+   * @param sequenceNumber The sequence associated with the first received RTP packet.
+   */
+  void onReceivingFirstPacket(long timestamp, int sequenceNumber);
+
+  /**
+   * Consumes the payload from the an RTP packet.
+   *
+   * @param data The RTP payload to consume.
+   * @param timestamp The timestamp of the RTP packet that transmitted the data. This number has no
+   *     unit, the duration conveyed by it depends on the frequency of the media that the RTP packet
+   *     is carrying.
+   * @param sequenceNumber The sequence number of the RTP packet.
+   * @param rtpMarker The marker bit of the RTP packet. The interpretation of this bit is specific
+   *     to each payload format.
+   * @throws ParserException If the data could not be parsed.
+   */
+  void consume(ParsableByteArray data, long timestamp, int sequenceNumber, boolean rtpMarker)
+      throws ParserException;
+
+  /**
+   * Seeks the reader.
+   *
+   * <p>This method must only be invoked after the PLAY request for seeking is acknowledged by the
+   * RTSP server.
+   *
+   * @param nextRtpTimestamp The timestamp of the first packet to arrive after seek.
+   * @param timeUs The server acknowledged seek time in microseconds.
+   */
+  void seek(long nextRtpTimestamp, long timeUs);
+}

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/rtp/reader/package-info.java

@@ -0,0 +1,19 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+@NonNullApi
+package com.google.android.exoplayer2.source.rtsp.rtp.reader;
+
+import com.google.android.exoplayer2.util.NonNullApi;

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/sdp/MediaDescription.java

@@ -0,0 +1,327 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.android.exoplayer2.source.rtsp.sdp;
+
+import static com.google.android.exoplayer2.source.rtsp.message.RtspMessageUtil.parseInt;
+import static com.google.android.exoplayer2.source.rtsp.sdp.SessionDescription.ATTR_FMTP;
+import static com.google.android.exoplayer2.source.rtsp.sdp.SessionDescription.ATTR_RTPMAP;
+import static com.google.android.exoplayer2.util.Assertions.checkArgument;
+import static com.google.android.exoplayer2.util.Assertions.checkState;
+import static com.google.android.exoplayer2.util.Util.castNonNull;
+
+import androidx.annotation.Nullable;
+import androidx.annotation.StringDef;
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.Format;
+import com.google.android.exoplayer2.ParserException;
+import com.google.android.exoplayer2.util.Util;
+import com.google.common.collect.ImmutableMap;
+import java.lang.annotation.Documented;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+/** Represents one media description section in a SDP message. */
+public final class MediaDescription {
+
+  /** Represents the mandatory RTPMAP attribute in MediaDescription. Reference RFC 2327 Page 22. */
+  public static final class RtpMapAttribute {
+
+    /** Parses the RTPMAP attribute value (with the part "a=rtpmap:" removed). */
+    public static RtpMapAttribute parse(String rtpmapString) throws ParserException {
+      String[] rtpmapInfo = Util.split(rtpmapString, " ");
+      checkArgument(rtpmapInfo.length == 2);
+      int payloadType = parseInt(rtpmapInfo[0]);
+
+      String[] mediaInfo = Util.split(rtpmapInfo[1], "/");
+      checkArgument(mediaInfo.length >= 2);
+      int clockRate = parseInt(mediaInfo[1]);
+      int encodingParameters = C.INDEX_UNSET;
+      if (mediaInfo.length == 3) {
+        encodingParameters = parseInt(mediaInfo[2]);
+      }
+      return new RtpMapAttribute(
+          payloadType, /* mediaEncoding= */ mediaInfo[0], clockRate, encodingParameters);
+    }
+
+    /** The assigned RTP payload type. */
+    public final int payloadType;
+    /** The encoding method used in the RTP stream. */
+    public final String mediaEncoding;
+    /** The clock rate used in the RTP stream. */
+    public final int clockRate;
+    /** The optional encoding parameter. */
+    public final int encodingParameters;
+
+    private RtpMapAttribute(
+        int payloadType, String mediaEncoding, int clockRate, int encodingParameters) {
+      this.payloadType = payloadType;
+      this.mediaEncoding = mediaEncoding;
+      this.clockRate = clockRate;
+      this.encodingParameters = encodingParameters;
+    }
+
+    @Override
+    public boolean equals(@Nullable Object o) {
+      if (this == o) {
+        return true;
+      }
+      if (o == null || getClass() != o.getClass()) {
+        return false;
+      }
+      RtpMapAttribute that = (RtpMapAttribute) o;
+      return payloadType == that.payloadType
+          && mediaEncoding.equals(that.mediaEncoding)
+          && clockRate == that.clockRate
+          && encodingParameters == that.encodingParameters;
+    }
+
+    @Override
+    public int hashCode() {
+      int result = 7;
+      result = 31 * result + payloadType;
+      result = 31 * result + mediaEncoding.hashCode();
+      result = 31 * result + clockRate;
+      result = 31 * result + encodingParameters;
+      return result;
+    }
+  }
+
+  /** Builder class for {@link MediaDescription}. */
+  public static final class Builder {
+    private final String mediaType;
+    private final int port;
+    private final String transportProtocol;
+    private final int payloadType;
+    private final ImmutableMap.Builder<String, String> attributesBuilder;
+
+    private int bitrate;
+    @Nullable private String mediaTitle;
+    @Nullable private String connection;
+    @Nullable private String key;
+
+    /**
+     * Creates a new instance.
+     *
+     * @param mediaType The media type.
+     * @param port The associated port number.
+     * @param transportProtocol The protocol used for data transport.
+     * @param payloadType The RTP payload type used for data transport.
+     */
+    public Builder(String mediaType, int port, String transportProtocol, int payloadType) {
+      this.mediaType = mediaType;
+      this.port = port;
+      this.transportProtocol = transportProtocol;
+      this.payloadType = payloadType;
+      attributesBuilder = new ImmutableMap.Builder<>();
+      bitrate = Format.NO_VALUE;
+    }
+
+    /**
+     * Sets {@link MediaDescription#mediaTitle}. The default is {@code null}.
+     *
+     * @param mediaTitle The assigned media title.
+     * @return This builder.
+     */
+    public Builder setMediaTitle(String mediaTitle) {
+      this.mediaTitle = mediaTitle;
+      return this;
+    }
+
+    /**
+     * Sets {@link MediaDescription#connection}. The default is {@code null}.
+     *
+     * @param connection The connection parameter.
+     * @return This builder.
+     */
+    public Builder setConnection(String connection) {
+      this.connection = connection;
+      return this;
+    }
+
+    /**
+     * Sets {@link MediaDescription#bitrate}. The default is {@link Format#NO_VALUE}.
+     *
+     * @param bitrate The estimated bitrate measured in bits per second.
+     * @return This builder.
+     */
+    public Builder setBitrate(int bitrate) {
+      this.bitrate = bitrate;
+      return this;
+    }
+
+    /**
+     * Sets {@link MediaDescription#key}. The default is {@code null}.
+     *
+     * @param key The encryption parameter.
+     * @return This builder.
+     */
+    public Builder setKey(String key) {
+      this.key = key;
+      return this;
+    }
+
+    /**
+     * Adds an attribute entry to {@link MediaDescription#attributes}.
+     *
+     * <p>Previously added attribute under the same name will be overwritten.
+     *
+     * @param attributeName The name of the attribute.
+     * @param attributeValue The value of the attribute, or "" if the attribute bears no value.
+     * @return This builder.
+     */
+    public Builder addAttribute(String attributeName, String attributeValue) {
+      attributesBuilder.put(attributeName, attributeValue);
+      return this;
+    }
+
+    /**
+     * Builds a new {@link MediaDescription} instance.
+     *
+     * @throws IllegalStateException When the rtpmap attribute (RFC 2327 Page 22) is not set, or
+     *     cannot be parsed.
+     */
+    public MediaDescription build() {
+      ImmutableMap<String, String> attributes = attributesBuilder.build();
+      try {
+        // rtpmap attribute is mandatory in RTSP (RFC2326 Section C.1.3).
+        checkState(attributes.containsKey(ATTR_RTPMAP));
+        RtpMapAttribute rtpMapAttribute =
+            RtpMapAttribute.parse(castNonNull(attributes.get(ATTR_RTPMAP)));
+        return new MediaDescription(this, attributes, rtpMapAttribute);
+      } catch (ParserException e) {
+        throw new IllegalStateException(e);
+      }
+    }
+  }
+
+  /** The media types allowed in a SDP media description. */
+  @Retention(RetentionPolicy.SOURCE)
+  @StringDef({MEDIA_TYPE_VIDEO, MEDIA_TYPE_AUDIO})
+  @Documented
+  public @interface MediaType {}
+  /** Audio media type. */
+  public static final String MEDIA_TYPE_AUDIO = "audio";
+  /** Video media type. */
+  public static final String MEDIA_TYPE_VIDEO = "video";
+  /** Default RTP/AVP profile. */
+  public static final String RTP_AVP_PROFILE = "RTP/AVP";
+
+  /** The {@link MediaType}. */
+  @MediaType public final String mediaType;
+  /** The associated port number. */
+  public final int port;
+  /** The protocol used for data transport. */
+  public final String transportProtocol;
+  /** The assigned RTP payload type. */
+  public final int payloadType;
+  /** The estimated connection bitrate in bits per second. */
+  public final int bitrate;
+  /** The assigned media title. */
+  @Nullable public final String mediaTitle;
+  // TODO(internal b/172331505) Parse the String representations into objects.
+  /** The connection parameters. */
+  @Nullable public final String connection;
+  /** The encryption parameter. */
+  @Nullable public final String key;
+  /** The media-specific attributes. */
+  public final ImmutableMap<String, String> attributes;
+  /** The mandatory rtpmap attribute in the media description (RFC2327 Page 22). */
+  public final RtpMapAttribute rtpMapAttribute;
+
+  /** Creates a new instance. */
+  private MediaDescription(
+      Builder builder, ImmutableMap<String, String> attributes, RtpMapAttribute rtpMapAttribute) {
+    this.mediaType = builder.mediaType;
+    this.port = builder.port;
+    this.transportProtocol = builder.transportProtocol;
+    this.payloadType = builder.payloadType;
+    this.mediaTitle = builder.mediaTitle;
+    this.connection = builder.connection;
+    this.bitrate = builder.bitrate;
+    this.key = builder.key;
+    this.attributes = attributes;
+    this.rtpMapAttribute = rtpMapAttribute;
+  }
+
+  @Override
+  public boolean equals(@Nullable Object o) {
+    if (this == o) {
+      return true;
+    }
+
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+
+    MediaDescription other = (MediaDescription) o;
+    return mediaType.equals(other.mediaType)
+        && port == other.port
+        && transportProtocol.equals(other.transportProtocol)
+        && payloadType == other.payloadType
+        && bitrate == other.bitrate
+        && attributes.equals(other.attributes)
+        && rtpMapAttribute.equals(other.rtpMapAttribute)
+        && Util.areEqual(mediaTitle, other.mediaTitle)
+        && Util.areEqual(connection, other.connection)
+        && Util.areEqual(key, other.key);
+  }
+
+  @Override
+  public int hashCode() {
+    int result = 7;
+    result = 31 * result + mediaType.hashCode();
+    result = 31 * result + port;
+    result = 31 * result + transportProtocol.hashCode();
+    result = 31 * result + payloadType;
+    result = 31 * result + bitrate;
+    result = 31 * result + attributes.hashCode();
+    result = 31 * result + rtpMapAttribute.hashCode();
+    result = 31 * result + (mediaTitle == null ? 0 : mediaTitle.hashCode());
+    result = 31 * result + (connection == null ? 0 : connection.hashCode());
+    result = 31 * result + (key == null ? 0 : key.hashCode());
+    return result;
+  }
+
+  /**
+   * Returns the FMTP attribute as a map of FMTP parameter names to values; or an empty map if the
+   * {@link MediaDescription} does not contain any FMTP attribute.
+   *
+   * <p>FMTP format reference: RFC2327 Page 27. The spaces around the FMTP attribute delimiters are
+   * removed. For example,
+   */
+  public ImmutableMap<String, String> getFmtpParametersAsMap() {
+    @Nullable String fmtpAttributeValue = attributes.get(ATTR_FMTP);
+    if (fmtpAttributeValue == null) {
+      return ImmutableMap.of();
+    }
+
+    // fmtp format: RFC2327 Page 27.
+    String[] fmtpComponents = Util.splitAtFirst(fmtpAttributeValue, " ");
+    checkArgument(fmtpComponents.length == 2, fmtpAttributeValue);
+
+    // Format of the parameter: RFC3640 Section 4.4.1:
+    //   <parameter name>=<value>[; <parameter name>=<value>].
+    String[] parameters = Util.split(fmtpComponents[1], ";\\s?");
+    ImmutableMap.Builder<String, String> formatParametersBuilder = new ImmutableMap.Builder<>();
+    for (String parameter : parameters) {
+      // The parameter values can bear equal signs, so splitAtFirst must be used.
+      String[] parameterPair = Util.splitAtFirst(parameter, "=");
+      formatParametersBuilder.put(parameterPair[0], parameterPair[1]);
+    }
+    return formatParametersBuilder.build();
+  }
+}

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/sdp/SessionDescription.java

@@ -0,0 +1,316 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.android.exoplayer2.source.rtsp.sdp;
+
+import static com.google.android.exoplayer2.util.Util.castNonNull;
+
+import android.net.Uri;
+import androidx.annotation.Nullable;
+import com.google.android.exoplayer2.Format;
+import com.google.android.exoplayer2.util.Util;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+
+/**
+ * Records all the information in a SDP message.
+ *
+ * <p>SDP messages encapsulate information on the media play back session, including session
+ * configuration information, formats of each playable track, etc. SDP is defined in RFC4566.
+ */
+public final class SessionDescription {
+
+  /** Builder class for {@link SessionDescription}. */
+  public static final class Builder {
+    private final ImmutableMap.Builder<String, String> attributesBuilder;
+    private final ImmutableList.Builder<MediaDescription> mediaDescriptionListBuilder;
+    private int bitrate;
+    @Nullable private String sessionName;
+    @Nullable private String origin;
+    @Nullable private String timing;
+    @Nullable private Uri uri;
+    @Nullable private String connection;
+    @Nullable private String key;
+    @Nullable private String sessionInfo;
+    @Nullable private String emailAddress;
+    @Nullable private String phoneNumber;
+
+    /** Creates a new instance. */
+    public Builder() {
+      attributesBuilder = new ImmutableMap.Builder<>();
+      mediaDescriptionListBuilder = new ImmutableList.Builder<>();
+      bitrate = Format.NO_VALUE;
+    }
+
+    /**
+     * Sets {@link SessionDescription#sessionName}.
+     *
+     * <p>This property must be set before calling {@link #build()}.
+     *
+     * @param sessionName The {@link SessionDescription#sessionName}.
+     * @return This builder.
+     */
+    public Builder setSessionName(String sessionName) {
+      this.sessionName = sessionName;
+      return this;
+    }
+
+    /**
+     * Sets {@link SessionDescription#sessionInfo}. The default is {@code null}.
+     *
+     * @param sessionInfo The {@link SessionDescription#sessionInfo}.
+     * @return This builder.
+     */
+    public Builder setSessionInfo(String sessionInfo) {
+      this.sessionInfo = sessionInfo;
+      return this;
+    }
+
+    /**
+     * Sets {@link SessionDescription#uri}. The default is {@code null}.
+     *
+     * @param uri The {@link SessionDescription#uri}.
+     * @return This builder.
+     */
+    public Builder setUri(Uri uri) {
+      this.uri = uri;
+      return this;
+    }
+
+    /**
+     * Sets {@link SessionDescription#origin}.
+     *
+     * <p>This property must be set before calling {@link #build()}.
+     *
+     * @param origin The {@link SessionDescription#origin}.
+     * @return This builder.
+     */
+    public Builder setOrigin(String origin) {
+      this.origin = origin;
+      return this;
+    }
+
+    /**
+     * Sets {@link SessionDescription#connection}. The default is {@code null}.
+     *
+     * @param connection The {@link SessionDescription#connection}.
+     * @return This builder.
+     */
+    public Builder setConnection(String connection) {
+      this.connection = connection;
+      return this;
+    }
+
+    /**
+     * Sets {@link SessionDescription#bitrate}. The default is {@link Format#NO_VALUE}.
+     *
+     * @param bitrate The {@link SessionDescription#bitrate} in bits per second.
+     * @return This builder.
+     */
+    public Builder setBitrate(int bitrate) {
+      this.bitrate = bitrate;
+      return this;
+    }
+
+    /**
+     * Sets {@link SessionDescription#timing}.
+     *
+     * <p>This property must be set before calling {@link #build()}.
+     *
+     * @param timing The {@link SessionDescription#timing}.
+     * @return This builder.
+     */
+    public Builder setTiming(String timing) {
+      this.timing = timing;
+      return this;
+    }
+
+    /**
+     * Sets {@link SessionDescription#key}. The default is {@code null}.
+     *
+     * @param key The {@link SessionDescription#key}.
+     * @return This builder.
+     */
+    public Builder setKey(String key) {
+      this.key = key;
+      return this;
+    }
+
+    /**
+     * Sets {@link SessionDescription#emailAddress}. The default is {@code null}.
+     *
+     * @param emailAddress The {@link SessionDescription#emailAddress}.
+     * @return This builder.
+     */
+    public Builder setEmailAddress(String emailAddress) {
+      this.emailAddress = emailAddress;
+      return this;
+    }
+
+    /**
+     * Sets {@link SessionDescription#phoneNumber}. The default is {@code null}.
+     *
+     * @param phoneNumber The {@link SessionDescription#phoneNumber}.
+     * @return This builder.
+     */
+    public Builder setPhoneNumber(String phoneNumber) {
+      this.phoneNumber = phoneNumber;
+      return this;
+    }
+
+    /**
+     * Adds one attribute to {@link SessionDescription#attributes}.
+     *
+     * @param attributeName The name of the attribute.
+     * @param attributeValue The value of the attribute.
+     * @return This builder.
+     */
+    public Builder addAttribute(String attributeName, String attributeValue) {
+      attributesBuilder.put(attributeName, attributeValue);
+      return this;
+    }
+
+    /**
+     * Adds one {@link MediaDescription} to the {@link SessionDescription#mediaDescriptionList}.
+     *
+     * @param mediaDescription The {@link MediaDescription}.
+     * @return This builder.
+     */
+    public Builder addMediaDescription(MediaDescription mediaDescription) {
+      mediaDescriptionListBuilder.add(mediaDescription);
+      return this;
+    }
+
+    /**
+     * Builds a new {@link SessionDescription} instance.
+     *
+     * @return The newly built {@link SessionDescription} instance.
+     * @throws IllegalStateException When one or more of {@link #sessionName}, {@link #timing} and
+     *     {@link #origin} is not set.
+     */
+    public SessionDescription build() {
+      if (sessionName == null || origin == null || timing == null) {
+        throw new IllegalStateException("One of more mandatory SDP fields are not set.");
+      }
+      return new SessionDescription(this);
+    }
+  }
+
+  /** The only supported SDP version, will be checked against every SDP message received. */
+  public static final String SUPPORTED_SDP_VERSION = "0";
+  /** The control attribute name. */
+  public static final String ATTR_CONTROL = "control";
+  /** The format property attribute name. */
+  public static final String ATTR_FMTP = "fmtp";
+  /** The length property attribute name. */
+  public static final String ATTR_LENGTH = "length";
+  /** The range property attribute name. */
+  public static final String ATTR_RANGE = "range";
+  /** The RTP format mapping property attribute name. */
+  public static final String ATTR_RTPMAP = "rtpmap";
+  /** The tool property attribute name. */
+  public static final String ATTR_TOOL = "tool";
+  /** The type property attribute name. */
+  public static final String ATTR_TYPE = "type";
+
+  /**
+   * All the session attributes, mapped from attribute name to value. The value is {@code ""} if not
+   * present.
+   */
+  public final ImmutableMap<String, String> attributes;
+  /**
+   * The {@link MediaDescription MediaDescriptions} for each media track included in the session.
+   */
+  public final ImmutableList<MediaDescription> mediaDescriptionList;
+  /** The name of a session. */
+  public final String sessionName;
+  // TODO(internal b/172331505) Parse the String representations into objects.
+  /** The origin sender info. */
+  public final String origin;
+  /** The timing info. */
+  public final String timing;
+  /** The estimated bitrate in bits per seconds. */
+  public final int bitrate;
+  /** The uri of a linked content. */
+  @Nullable public final Uri uri;
+  /** The connection info. */
+  @Nullable public final String connection;
+  /** The encryption method and key info. */
+  @Nullable public final String key;
+  /** The email info. */
+  @Nullable public final String emailAddress;
+  /** The phone number info. */
+  @Nullable public final String phoneNumber;
+  /** The session info, a detailed description of the session. */
+  @Nullable public final String sessionInfo;
+
+  /** Creates a new instance. */
+  private SessionDescription(Builder builder) {
+    this.attributes = builder.attributesBuilder.build();
+    this.mediaDescriptionList = builder.mediaDescriptionListBuilder.build();
+    this.sessionName = castNonNull(builder.sessionName);
+    this.origin = castNonNull(builder.origin);
+    this.timing = castNonNull(builder.timing);
+    this.uri = builder.uri;
+    this.connection = builder.connection;
+    this.bitrate = builder.bitrate;
+    this.key = builder.key;
+    this.emailAddress = builder.emailAddress;
+    this.phoneNumber = builder.phoneNumber;
+    this.sessionInfo = builder.sessionInfo;
+  }
+
+  @Override
+  public boolean equals(@Nullable Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+    SessionDescription that = (SessionDescription) o;
+    return bitrate == that.bitrate
+        && attributes.equals(that.attributes)
+        && mediaDescriptionList.equals(that.mediaDescriptionList)
+        && origin.equals(that.origin)
+        && sessionName.equals(that.sessionName)
+        && timing.equals(that.timing)
+        && Util.areEqual(sessionInfo, that.sessionInfo)
+        && Util.areEqual(uri, that.uri)
+        && Util.areEqual(emailAddress, that.emailAddress)
+        && Util.areEqual(phoneNumber, that.phoneNumber)
+        && Util.areEqual(connection, that.connection)
+        && Util.areEqual(key, that.key);
+  }
+
+  @Override
+  public int hashCode() {
+    int result = 7;
+    result = 31 * result + attributes.hashCode();
+    result = 31 * result + mediaDescriptionList.hashCode();
+    result = 31 * result + origin.hashCode();
+    result = 31 * result + sessionName.hashCode();
+    result = 31 * result + timing.hashCode();
+    result = 31 * result + bitrate;
+    result = 31 * result + (sessionInfo == null ? 0 : sessionInfo.hashCode());
+    result = 31 * result + (uri == null ? 0 : uri.hashCode());
+    result = 31 * result + (emailAddress == null ? 0 : emailAddress.hashCode());
+    result = 31 * result + (phoneNumber == null ? 0 : phoneNumber.hashCode());
+    result = 31 * result + (connection == null ? 0 : connection.hashCode());
+    result = 31 * result + (key == null ? 0 : key.hashCode());
+    return result;
+  }
+}

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/sdp/SessionDescriptionParser.java

@@ -0,0 +1,231 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.android.exoplayer2.source.rtsp.sdp;
+
+import static com.google.android.exoplayer2.source.rtsp.sdp.SessionDescription.SUPPORTED_SDP_VERSION;
+import static com.google.android.exoplayer2.util.Assertions.checkArgument;
+import static com.google.android.exoplayer2.util.Assertions.checkNotNull;
+import static com.google.common.base.Strings.nullToEmpty;
+
+import android.net.Uri;
+import androidx.annotation.Nullable;
+import com.google.android.exoplayer2.ParserException;
+import com.google.android.exoplayer2.util.Util;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+/** Parses a String based SDP message into {@link SessionDescription}. */
+public final class SessionDescriptionParser {
+  // SDP line always starts with an one letter tag, followed by an equal sign. The information
+  // under the given tag follows an optional space.
+  private static final Pattern SDP_LINE_PATTERN = Pattern.compile("([a-z])=\\s?(.+)");
+  // Matches an attribute line (with a= sdp tag removed. Example: range:npt=0-50.0).
+  // Attribute can also be a flag, i.e. without a value, like recvonly.
+  private static final Pattern ATTRIBUTE_PATTERN = Pattern.compile("([0-9A-Za-z-]+)(?::(.*))?");
+  // SDP media description line: <mediaType> <port> <transmissionProtocol> <rtpPayloadType>
+  // For instance: audio 0 RTP/AVP 97
+  private static final Pattern MEDIA_DESCRIPTION_PATTERN =
+      Pattern.compile("(\\S+)\\s(\\S+)\\s(\\S+)\\s(\\S+)");
+
+  private static final String CRLF = "\r\n";
+
+  private static final String VERSION_TYPE = "v";
+  private static final String ORIGIN_TYPE = "o";
+  private static final String SESSION_TYPE = "s";
+  private static final String INFORMATION_TYPE = "i";
+  private static final String URI_TYPE = "u";
+  private static final String EMAIL_TYPE = "e";
+  private static final String PHONE_NUMBER_TYPE = "p";
+  private static final String CONNECTION_TYPE = "c";
+  private static final String BANDWIDTH_TYPE = "b";
+  private static final String TIMING_TYPE = "t";
+  private static final String KEY_TYPE = "k";
+  private static final String ATTRIBUTE_TYPE = "a";
+  private static final String MEDIA_TYPE = "m";
+  private static final String REPEAT_TYPE = "r";
+  private static final String ZONE_TYPE = "z";
+
+  /**
+   * Parses a String based SDP message into {@link SessionDescription}.
+   *
+   * @throws ParserException On SDP message line that cannot be parsed, or when one or more of the
+   *     mandatory SDP fields {@link SessionDescription#timing}, {@link SessionDescription#origin}
+   *     and {@link SessionDescription#sessionName} are not set.
+   */
+  public static SessionDescription parse(String sdpString) throws ParserException {
+    SessionDescription.Builder sessionDescriptionBuilder = new SessionDescription.Builder();
+    @Nullable MediaDescription.Builder mediaDescriptionBuilder = null;
+
+    // Lines are separated by an CRLF.
+    for (String line : Util.split(sdpString, CRLF)) {
+      if ("".equals(line)) {
+        continue;
+      }
+
+      Matcher matcher = SDP_LINE_PATTERN.matcher(line);
+      if (!matcher.matches()) {
+        throw new ParserException("Malformed SDP line: " + line);
+      }
+
+      String sdpType = checkNotNull(matcher.group(1));
+      String sdpValue = checkNotNull(matcher.group(2));
+
+      switch (sdpType) {
+        case VERSION_TYPE:
+          if (!SUPPORTED_SDP_VERSION.equals(sdpValue)) {
+            throw new ParserException(String.format("SDP version %s is not supported.", sdpValue));
+          }
+          break;
+
+        case ORIGIN_TYPE:
+          sessionDescriptionBuilder.setOrigin(sdpValue);
+          break;
+
+        case SESSION_TYPE:
+          sessionDescriptionBuilder.setSessionName(sdpValue);
+          break;
+
+        case INFORMATION_TYPE:
+          if (mediaDescriptionBuilder == null) {
+            sessionDescriptionBuilder.setSessionInfo(sdpValue);
+          } else {
+            mediaDescriptionBuilder.setMediaTitle(sdpValue);
+          }
+          break;
+
+        case URI_TYPE:
+          sessionDescriptionBuilder.setUri(Uri.parse(sdpValue));
+          break;
+
+        case EMAIL_TYPE:
+          sessionDescriptionBuilder.setEmailAddress(sdpValue);
+          break;
+
+        case PHONE_NUMBER_TYPE:
+          sessionDescriptionBuilder.setPhoneNumber(sdpValue);
+          break;
+
+        case CONNECTION_TYPE:
+          if (mediaDescriptionBuilder == null) {
+            sessionDescriptionBuilder.setConnection(sdpValue);
+          } else {
+            mediaDescriptionBuilder.setConnection(sdpValue);
+          }
+          break;
+
+        case BANDWIDTH_TYPE:
+          String[] bandwidthComponents = Util.split(sdpValue, ":\\s?");
+          checkArgument(bandwidthComponents.length == 2);
+          int bitrateKbps = Integer.parseInt(bandwidthComponents[1]);
+
+          // Converting kilobits per second to bits per second.
+          if (mediaDescriptionBuilder == null) {
+            sessionDescriptionBuilder.setBitrate(bitrateKbps * 1000);
+          } else {
+            mediaDescriptionBuilder.setBitrate(bitrateKbps * 1000);
+          }
+          break;
+
+        case TIMING_TYPE:
+          sessionDescriptionBuilder.setTiming(sdpValue);
+          break;
+
+        case KEY_TYPE:
+          if (mediaDescriptionBuilder == null) {
+            sessionDescriptionBuilder.setKey(sdpValue);
+          } else {
+            mediaDescriptionBuilder.setKey(sdpValue);
+          }
+          break;
+
+        case ATTRIBUTE_TYPE:
+          matcher = ATTRIBUTE_PATTERN.matcher(sdpValue);
+          if (!matcher.matches()) {
+            throw new ParserException("Malformed Attribute line: " + line);
+          }
+
+          String attributeName = checkNotNull(matcher.group(1));
+          // The second catching group is optional and thus could be null.
+          String attributeValue = nullToEmpty(matcher.group(2));
+
+          if (mediaDescriptionBuilder == null) {
+            sessionDescriptionBuilder.addAttribute(attributeName, attributeValue);
+          } else {
+            mediaDescriptionBuilder.addAttribute(attributeName, attributeValue);
+          }
+          break;
+
+        case MEDIA_TYPE:
+          if (mediaDescriptionBuilder != null) {
+            addMediaDescriptionToSession(sessionDescriptionBuilder, mediaDescriptionBuilder);
+          }
+          mediaDescriptionBuilder = parseMediaDescriptionLine(sdpValue);
+          break;
+        case REPEAT_TYPE:
+        case ZONE_TYPE:
+        default:
+          // Not handled.
+      }
+    }
+
+    if (mediaDescriptionBuilder != null) {
+      addMediaDescriptionToSession(sessionDescriptionBuilder, mediaDescriptionBuilder);
+    }
+
+    try {
+      return sessionDescriptionBuilder.build();
+    } catch (IllegalStateException e) {
+      throw new ParserException(e);
+    }
+  }
+
+  private static void addMediaDescriptionToSession(
+      SessionDescription.Builder sessionDescriptionBuilder,
+      MediaDescription.Builder mediaDescriptionBuilder)
+      throws ParserException {
+    try {
+      sessionDescriptionBuilder.addMediaDescription(mediaDescriptionBuilder.build());
+    } catch (IllegalStateException e) {
+      throw new ParserException(e);
+    }
+  }
+
+  private static MediaDescription.Builder parseMediaDescriptionLine(String line)
+      throws ParserException {
+    Matcher matcher = MEDIA_DESCRIPTION_PATTERN.matcher(line);
+    if (!matcher.matches()) {
+      throw new ParserException("Malformed SDP media description line: " + line);
+    }
+    String mediaType = checkNotNull(matcher.group(1));
+    String portString = checkNotNull(matcher.group(2));
+    String transportProtocol = checkNotNull(matcher.group(3));
+    String payloadTypeString = checkNotNull(matcher.group(4));
+
+    try {
+      return new MediaDescription.Builder(
+          mediaType,
+          Integer.parseInt(portString),
+          transportProtocol,
+          Integer.parseInt(payloadTypeString));
+    } catch (NumberFormatException e) {
+      throw new ParserException("Malformed SDP media description line: " + line, e);
+    }
+  }
+
+  /** Prevents initialization. */
+  private SessionDescriptionParser() {}
+}

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/sdp/package-info.java

@@ -0,0 +1,19 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+@NonNullApi
+package com.google.android.exoplayer2.source.rtsp.sdp;
+
+import com.google.android.exoplayer2.util.NonNullApi;

library/rtsp/src/test/AndroidManifest.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright 2020 The Android Open Source Project
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+
+<manifest package="com.google.android.exoplayer2.source.rtsp.test">
+  <uses-sdk/>
+</manifest>

library/rtsp/src/test/java/com/google/android/exoplayer2/source/rtsp/RtspClientTest.java

@@ -0,0 +1,78 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.source.rtsp;
+
+import static com.google.android.exoplayer2.util.Assertions.checkNotNull;
+
+import android.net.Uri;
+import androidx.annotation.Nullable;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import com.google.android.exoplayer2.robolectric.RobolectricUtil;
+import com.google.android.exoplayer2.source.rtsp.RtspClient.SessionInfoListener;
+import com.google.android.exoplayer2.util.Util;
+import com.google.common.collect.ImmutableList;
+import java.util.concurrent.atomic.AtomicBoolean;
+import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+/** Tests the {@link RtspClient} using the {@link RtspServer}. */
+@RunWith(AndroidJUnit4.class)
+public final class RtspClientTest {
+
+  private @MonotonicNonNull RtspClient rtspClient;
+  private @MonotonicNonNull RtspServer rtspServer;
+
+  @Before
+  public void setUp() {
+    rtspServer = new RtspServer();
+  }
+
+  @After
+  public void tearDown() {
+    Util.closeQuietly(rtspServer);
+    Util.closeQuietly(rtspClient);
+  }
+
+  @Test
+  public void connectServerAndClient_withServerSupportsOnlyOptions_sessionTimelineRequestFails()
+      throws Exception {
+    int serverRtspPortNumber = checkNotNull(rtspServer).startAndGetPortNumber();
+
+    AtomicBoolean sessionTimelineUpdateEventReceived = new AtomicBoolean();
+    rtspClient =
+        new RtspClient(
+            new SessionInfoListener() {
+              @Override
+              public void onSessionTimelineUpdated(
+                  RtspSessionTiming timing, ImmutableList<RtspMediaTrack> tracks) {}
+
+              @Override
+              public void onSessionTimelineRequestFailed(
+                  String message, @Nullable Throwable cause) {
+                sessionTimelineUpdateEventReceived.set(true);
+              }
+            },
+            /* userAgent= */ "ExoPlayer:RtspClientTest",
+            /* uri= */ Uri.parse(
+                Util.formatInvariant("rtsp://localhost:%d/test", serverRtspPortNumber)));
+    rtspClient.start();
+
+    RobolectricUtil.runMainLooperUntil(sessionTimelineUpdateEventReceived::get);
+  }
+}

library/rtsp/src/test/java/com/google/android/exoplayer2/source/rtsp/RtspMediaPeriodTest.java

@@ -0,0 +1,102 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.source.rtsp;
+
+import static com.google.android.exoplayer2.robolectric.RobolectricUtil.runMainLooperUntil;
+import static com.google.common.truth.Truth.assertThat;
+
+import android.net.Uri;
+import androidx.annotation.Nullable;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.source.MediaPeriod;
+import com.google.android.exoplayer2.source.rtsp.sdp.MediaDescription;
+import com.google.android.exoplayer2.source.rtsp.sdp.SessionDescription;
+import com.google.android.exoplayer2.upstream.DefaultAllocator;
+import com.google.common.collect.ImmutableList;
+import java.util.concurrent.atomic.AtomicBoolean;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+/** Unit test for {@link RtspMediaPeriod}. */
+@RunWith(AndroidJUnit4.class)
+public class RtspMediaPeriodTest {
+
+  private static final RtspClient PLACEHOLDER_RTSP_CLIENT =
+      new RtspClient(
+          new RtspClient.SessionInfoListener() {
+            @Override
+            public void onSessionTimelineUpdated(
+                RtspSessionTiming timing, ImmutableList<RtspMediaTrack> tracks) {}
+            @Override
+            public void onSessionTimelineRequestFailed(String message, @Nullable Throwable cause) {}
+          },
+          /* userAgent= */ null,
+          Uri.EMPTY);
+
+  @Test
+  public void prepare_startsLoading() throws Exception {
+    RtspMediaPeriod rtspMediaPeriod =
+        new RtspMediaPeriod(
+            new DefaultAllocator(/* trimOnReset= */ true, C.DEFAULT_BUFFER_SEGMENT_SIZE),
+            ImmutableList.of(
+                new RtspMediaTrack(
+                    new MediaDescription.Builder(
+                            /* mediaType= */ MediaDescription.MEDIA_TYPE_VIDEO,
+                            /* port= */ 0,
+                            /* transportProtocol= */ MediaDescription.RTP_AVP_PROFILE,
+                            /* payloadType= */ 96)
+                        .setConnection("IN IP4 0.0.0.0")
+                        .setBitrate(500_000)
+                        .addAttribute(SessionDescription.ATTR_RTPMAP, "96 H264/90000")
+                        .addAttribute(
+                            SessionDescription.ATTR_FMTP,
+                            "96 packetization-mode=1;profile-level-id=64001F;sprop-parameter-sets=Z2QAH6zZQPARabIAAAMACAAAAwGcHjBjLA==,aOvjyyLA")
+                        .addAttribute(SessionDescription.ATTR_CONTROL, "track1")
+                        .build(),
+                    Uri.parse("rtsp://localhost/test"))),
+            PLACEHOLDER_RTSP_CLIENT);
+
+    AtomicBoolean prepareCallbackCalled = new AtomicBoolean(false);
+    rtspMediaPeriod.prepare(
+        new MediaPeriod.Callback() {
+          @Override
+          public void onPrepared(MediaPeriod mediaPeriod) {
+            prepareCallbackCalled.set(true);
+          }
+
+          @Override
+          public void onContinueLoadingRequested(MediaPeriod source) {
+            source.continueLoading(/* positionUs= */ 0);
+          }
+        },
+        /* positionUs= */ 0);
+
+    runMainLooperUntil(prepareCallbackCalled::get);
+    rtspMediaPeriod.release();
+  }
+
+  @Test
+  public void getBufferedPositionUs_withNoRtspMediaTracks_returnsEndOfSource() {
+    RtspMediaPeriod rtspMediaPeriod =
+        new RtspMediaPeriod(
+            new DefaultAllocator(/* trimOnReset= */ true, C.DEFAULT_BUFFER_SEGMENT_SIZE),
+            ImmutableList.of(),
+            PLACEHOLDER_RTSP_CLIENT);
+
+    assertThat(rtspMediaPeriod.getBufferedPositionUs()).isEqualTo(C.TIME_END_OF_SOURCE);
+  }
+}

library/rtsp/src/test/java/com/google/android/exoplayer2/source/rtsp/RtspMediaTrackTest.java

@@ -0,0 +1,260 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.source.rtsp;
+
+import static com.google.android.exoplayer2.source.rtsp.sdp.MediaDescription.MEDIA_TYPE_AUDIO;
+import static com.google.android.exoplayer2.source.rtsp.sdp.MediaDescription.MEDIA_TYPE_VIDEO;
+import static com.google.android.exoplayer2.source.rtsp.sdp.MediaDescription.RTP_AVP_PROFILE;
+import static com.google.android.exoplayer2.source.rtsp.sdp.SessionDescription.ATTR_CONTROL;
+import static com.google.android.exoplayer2.source.rtsp.sdp.SessionDescription.ATTR_FMTP;
+import static com.google.android.exoplayer2.source.rtsp.sdp.SessionDescription.ATTR_RTPMAP;
+import static com.google.common.truth.Truth.assertThat;
+import static org.junit.Assert.assertThrows;
+
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import com.google.android.exoplayer2.Format;
+import com.google.android.exoplayer2.audio.AacUtil;
+import com.google.android.exoplayer2.source.rtsp.rtp.RtpPayloadFormat;
+import com.google.android.exoplayer2.source.rtsp.sdp.MediaDescription;
+import com.google.android.exoplayer2.util.MimeTypes;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+/** Unit test for {@link RtspMediaTrack}. */
+@RunWith(AndroidJUnit4.class)
+public class RtspMediaTrackTest {
+
+  @Test
+  public void generatePayloadFormat_withH264MediaDescription_succeeds() throws Exception {
+    MediaDescription mediaDescription =
+        new MediaDescription.Builder(MEDIA_TYPE_VIDEO, 0, RTP_AVP_PROFILE, 96)
+            .setConnection("IN IP4 0.0.0.0")
+            .setBitrate(500_000)
+            .addAttribute(ATTR_RTPMAP, "96 H264/90000")
+            .addAttribute(
+                ATTR_FMTP,
+                "96 packetization-mode=1;profile-level-id=64001F;sprop-parameter-sets=Z2QAH6zZQPARabIAAAMACAAAAwGcHjBjLA==,aOvjyyLA")
+            .addAttribute(ATTR_CONTROL, "track1")
+            .build();
+
+    RtpPayloadFormat format = RtspMediaTrack.generatePayloadFormat(mediaDescription);
+    RtpPayloadFormat expectedFormat =
+        new RtpPayloadFormat(
+            new Format.Builder()
+                .setSampleMimeType(MimeTypes.VIDEO_H264)
+                .setAverageBitrate(500_000)
+                .setPixelWidthHeightRatio(1.0f)
+                .setHeight(544)
+                .setWidth(960)
+                .setCodecs("avc1.64001F")
+                .setInitializationData(
+                    ImmutableList.of(
+                        new byte[] {
+                          0, 0, 0, 1, 103, 100, 0, 31, -84, -39, 64, -16, 17, 105, -78, 0, 0, 3, 0,
+                          8, 0, 0, 3, 1, -100, 30, 48, 99, 44
+                        },
+                        new byte[] {0, 0, 0, 1, 104, -21, -29, -53, 34, -64}))
+                .build(),
+            /* rtpPayloadType= */ 96,
+            /* clockRate= */ 90_000,
+            /* fmtpParameters= */ ImmutableMap.of(
+                "packetization-mode", "1",
+                "profile-level-id", "64001F",
+                "sprop-parameter-sets", "Z2QAH6zZQPARabIAAAMACAAAAwGcHjBjLA==,aOvjyyLA"));
+
+    assertThat(format).isEqualTo(expectedFormat);
+  }
+
+  @Test
+  public void generatePayloadFormat_withAacMediaDescription_succeeds() throws Exception {
+    MediaDescription mediaDescription =
+        new MediaDescription.Builder(MEDIA_TYPE_AUDIO, 0, RTP_AVP_PROFILE, 97)
+            .setConnection("IN IP4 0.0.0.0")
+            .setBitrate(96_000)
+            .addAttribute(ATTR_RTPMAP, "97 MPEG4-GENERIC/44100")
+            .addAttribute(
+                ATTR_FMTP,
+                "97 streamtype=5; profile-level-id=1; mode=AAC-hbr; sizelength=13; indexlength=3;"
+                    + " indexdeltalength=3; config=1208")
+            .addAttribute(ATTR_CONTROL, "track2")
+            .build();
+
+    RtpPayloadFormat format = RtspMediaTrack.generatePayloadFormat(mediaDescription);
+    RtpPayloadFormat expectedFormat =
+        new RtpPayloadFormat(
+            new Format.Builder()
+                .setSampleMimeType(MimeTypes.AUDIO_AAC)
+                .setChannelCount(1)
+                .setSampleRate(44100)
+                .setAverageBitrate(96_000)
+                .setCodecs("mp4a.40.1")
+                .setInitializationData(
+                    ImmutableList.of(
+                        AacUtil.buildAacLcAudioSpecificConfig(
+                            /* sampleRate= */ 44_100, /* channelCount= */ 1)))
+                .build(),
+            /* rtpPayloadType= */ 97,
+            /* clockRate= */ 44_100,
+            /* fmtpParameters= */ new ImmutableMap.Builder<String, String>()
+                .put("streamtype", "5")
+                .put("profile-level-id", "1")
+                .put("mode", "AAC-hbr")
+                .put("sizelength", "13")
+                .put("indexlength", "3")
+                .put("indexdeltalength", "3")
+                .put("config", "1208")
+                .build());
+
+    assertThat(format).isEqualTo(expectedFormat);
+  }
+
+  @Test
+  public void generatePayloadFormat_withAc3MediaDescriptionWithDefaultChannelCount_succeeds()
+      throws Exception {
+    MediaDescription mediaDescription =
+        new MediaDescription.Builder(MEDIA_TYPE_AUDIO, 0, RTP_AVP_PROFILE, 97)
+            .setConnection("IN IP4 0.0.0.0")
+            .setBitrate(48_000)
+            .addAttribute(ATTR_RTPMAP, "97 AC3/48000")
+            .addAttribute(ATTR_CONTROL, "track2")
+            .build();
+
+    RtpPayloadFormat format = RtspMediaTrack.generatePayloadFormat(mediaDescription);
+    RtpPayloadFormat expectedFormat =
+        new RtpPayloadFormat(
+            new Format.Builder()
+                .setSampleMimeType(MimeTypes.AUDIO_AC3)
+                .setChannelCount(6)
+                .setSampleRate(48000)
+                .setAverageBitrate(48_000)
+                .build(),
+            /* rtpPayloadType= */ 97,
+            /* clockRate= */ 48000,
+            /* fmtpParameters= */ ImmutableMap.of());
+
+    assertThat(format).isEqualTo(expectedFormat);
+  }
+
+  @Test
+  public void generatePayloadFormat_withAc3MediaDescription_succeeds() throws Exception {
+    MediaDescription mediaDescription =
+        new MediaDescription.Builder(MEDIA_TYPE_AUDIO, 0, RTP_AVP_PROFILE, 97)
+            .setConnection("IN IP4 0.0.0.0")
+            .setBitrate(48_000)
+            .addAttribute(ATTR_RTPMAP, "97 AC3/48000/2")
+            .addAttribute(ATTR_CONTROL, "track2")
+            .build();
+
+    RtpPayloadFormat format = RtspMediaTrack.generatePayloadFormat(mediaDescription);
+    RtpPayloadFormat expectedFormat =
+        new RtpPayloadFormat(
+            new Format.Builder()
+                .setSampleMimeType(MimeTypes.AUDIO_AC3)
+                .setChannelCount(2)
+                .setSampleRate(48000)
+                .setAverageBitrate(48_000)
+                .build(),
+            /* rtpPayloadType= */ 97,
+            /* clockRate= */ 48000,
+            /* fmtpParameters= */ ImmutableMap.of());
+
+    assertThat(format).isEqualTo(expectedFormat);
+  }
+
+  @Test
+  public void
+      generatePayloadFormat_withAacMediaDescriptionMissingFmtpAttribute_throwsIllegalArgumentException() {
+    MediaDescription mediaDescription =
+        new MediaDescription.Builder(MEDIA_TYPE_AUDIO, 0, RTP_AVP_PROFILE, 97)
+            .setConnection("IN IP4 0.0.0.0")
+            .setBitrate(96_000)
+            .addAttribute(ATTR_RTPMAP, "97 MPEG4-GENERIC/44100")
+            .addAttribute(ATTR_CONTROL, "track2")
+            .build();
+    assertThrows(
+        IllegalArgumentException.class,
+        () -> RtspMediaTrack.generatePayloadFormat(mediaDescription));
+  }
+
+  @Test
+  public void
+      generatePayloadFormat_withMediaDescriptionMissingProfileLevel_throwsIllegalArgumentException() {
+    MediaDescription mediaDescription =
+        new MediaDescription.Builder(MEDIA_TYPE_AUDIO, 0, RTP_AVP_PROFILE, 97)
+            .setConnection("IN IP4 0.0.0.0")
+            .setBitrate(96_000)
+            .addAttribute(ATTR_RTPMAP, "97 MPEG4-GENERIC/44100")
+            .addAttribute(
+                ATTR_FMTP,
+                "97 streamtype=5;mode=AAC-hbr;sizelength=13;indexlength=3;indexdeltalength=3;config=1208")
+            .addAttribute(ATTR_CONTROL, "track2")
+            .build();
+    assertThrows(
+        IllegalArgumentException.class,
+        () -> RtspMediaTrack.generatePayloadFormat(mediaDescription));
+  }
+
+  @Test
+  public void
+      generatePayloadFormat_withH264MediaDescriptionMissingFmtpAttribute_throwsIllegalArgumentException() {
+    MediaDescription mediaDescription =
+        new MediaDescription.Builder(MEDIA_TYPE_VIDEO, 0, RTP_AVP_PROFILE, 96)
+            .setConnection("IN IP4 0.0.0.0")
+            .setBitrate(500_000)
+            .addAttribute(ATTR_RTPMAP, "96 H264/90000")
+            .addAttribute(ATTR_CONTROL, "track1")
+            .build();
+    assertThrows(
+        IllegalArgumentException.class,
+        () -> RtspMediaTrack.generatePayloadFormat(mediaDescription));
+  }
+
+  @Test
+  public void
+      generatePayloadFormat_withH264MediaDescriptionMissingProfileLevel_throwsIllegalArgumentException() {
+    MediaDescription mediaDescription =
+        new MediaDescription.Builder(MEDIA_TYPE_VIDEO, 0, RTP_AVP_PROFILE, 96)
+            .setConnection("IN IP4 0.0.0.0")
+            .setBitrate(500_000)
+            .addAttribute(ATTR_RTPMAP, "96 H264/90000")
+            .addAttribute(
+                ATTR_FMTP,
+                "96 packetization-mode=1;sprop-parameter-sets=Z2QAH6zZQPARabIAAAMACAAAAwGcHjBjLA==,aOvjyyLA")
+            .addAttribute(ATTR_CONTROL, "track1")
+            .build();
+    assertThrows(
+        IllegalArgumentException.class,
+        () -> RtspMediaTrack.generatePayloadFormat(mediaDescription));
+  }
+
+  @Test
+  public void
+      generatePayloadFormat_withH264MediaDescriptionMissingSpropParameter_throwsIllegalArgumentException() {
+    MediaDescription mediaDescription =
+        new MediaDescription.Builder(MEDIA_TYPE_VIDEO, 0, RTP_AVP_PROFILE, 96)
+            .setConnection("IN IP4 0.0.0.0")
+            .setBitrate(500_000)
+            .addAttribute(ATTR_RTPMAP, "96 H264/90000")
+            .addAttribute(ATTR_FMTP, "96 packetization-mode=1;profile-level-id=64001F")
+            .addAttribute(ATTR_CONTROL, "track1")
+            .build();
+    assertThrows(
+        IllegalArgumentException.class,
+        () -> RtspMediaTrack.generatePayloadFormat(mediaDescription));
+  }
+}

library/rtsp/src/test/java/com/google/android/exoplayer2/source/rtsp/RtspServer.java

@@ -0,0 +1,155 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.source.rtsp;
+
+import static com.google.android.exoplayer2.source.rtsp.message.RtspRequest.METHOD_OPTIONS;
+import static com.google.android.exoplayer2.util.Assertions.checkNotNull;
+
+import android.os.Handler;
+import android.os.Looper;
+import com.google.android.exoplayer2.source.rtsp.message.RtspHeaders;
+import com.google.android.exoplayer2.source.rtsp.message.RtspMessageChannel;
+import com.google.android.exoplayer2.source.rtsp.message.RtspMessageUtil;
+import com.google.android.exoplayer2.source.rtsp.message.RtspRequest;
+import com.google.android.exoplayer2.source.rtsp.message.RtspResponse;
+import com.google.android.exoplayer2.util.Util;
+import java.io.Closeable;
+import java.io.IOException;
+import java.net.InetAddress;
+import java.net.ServerSocket;
+import java.net.Socket;
+import java.net.SocketException;
+import java.util.List;
+import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
+
+/** The RTSP server. */
+public final class RtspServer implements Closeable {
+
+  private static final String PUBLIC_SUPPORTED_METHODS = "OPTIONS";
+  /** RTSP error Method Not Allowed (RFC2326 Section 7.1.1). */
+  private static final int STATUS_METHOD_NOT_ALLOWED = 405;
+
+  private final Thread listenerThread;
+  /** Runs on the thread on which the constructor was called. */
+  private final Handler mainHandler;
+
+  private @MonotonicNonNull ServerSocket serverSocket;
+  private @MonotonicNonNull RtspMessageChannel connectedClient;
+
+  private volatile boolean isCanceled;
+
+  /**
+   * Creates a new instance.
+   *
+   * <p>The constructor must be called on a {@link Looper} thread.
+   */
+  public RtspServer() {
+    listenerThread =
+        new Thread(this::listenToIncomingRtspConnection, "ExoPlayerTest:RtspConnectionMonitor");
+    mainHandler = Util.createHandlerForCurrentLooper();
+  }
+
+  /**
+   * Starts the server. The server starts listening to incoming RTSP connections.
+   *
+   * <p>The user must call {@link #close} if {@link IOException} is thrown. Closed instances must
+   * not be started again.
+   *
+   * @return The server side port number for RTSP connections.
+   */
+  public int startAndGetPortNumber() throws IOException {
+    // Auto assign port and allow only one client connection (backlog).
+    serverSocket =
+        new ServerSocket(/* port= */ 0, /* backlog= */ 1, InetAddress.getByName(/* host= */ null));
+    listenerThread.start();
+    return serverSocket.getLocalPort();
+  }
+
+  @Override
+  public void close() throws IOException {
+    isCanceled = true;
+    if (serverSocket != null) {
+      serverSocket.close();
+    }
+    if (connectedClient != null) {
+      connectedClient.close();
+    }
+  }
+
+  private void handleNewClientConnected(Socket socket) {
+    try {
+      connectedClient = new RtspMessageChannel(new MessageListener());
+      connectedClient.openSocket(socket);
+    } catch (IOException e) {
+      Util.closeQuietly(connectedClient);
+      // Log the error.
+      e.printStackTrace();
+    }
+  }
+
+  private final class MessageListener implements RtspMessageChannel.MessageListener {
+    @Override
+    public void onRtspMessageReceived(List<String> message) {
+      RtspRequest request = RtspMessageUtil.parseRequest(message);
+      switch (request.method) {
+        case METHOD_OPTIONS:
+          onOptionsRequestReceived(request);
+          break;
+        default:
+          connectedClient.send(
+              RtspMessageUtil.serializeResponse(
+                  new RtspResponse(
+                      /* status= */ STATUS_METHOD_NOT_ALLOWED,
+                      /* headers= */ new RtspHeaders.Builder()
+                          .add(
+                              RtspHeaders.CSEQ, checkNotNull(request.headers.get(RtspHeaders.CSEQ)))
+                          .build(),
+                      /* messageBody= */ "")));
+      }
+    }
+
+    private void onOptionsRequestReceived(RtspRequest request) {
+      connectedClient.send(
+          RtspMessageUtil.serializeResponse(
+              new RtspResponse(
+                  /* status= */ 200,
+                  /* headers= */ new RtspHeaders.Builder()
+                      .add(RtspHeaders.CSEQ, checkNotNull(request.headers.get(RtspHeaders.CSEQ)))
+                      .add(RtspHeaders.PUBLIC, PUBLIC_SUPPORTED_METHODS)
+                      .build(),
+                  /* messageBody= */ "")));
+    }
+  }
+
+  private void listenToIncomingRtspConnection() {
+    while (!isCanceled) {
+      try {
+        Socket acceptedClientSocket = serverSocket.accept();
+        mainHandler.post(() -> handleNewClientConnected(acceptedClientSocket));
+      } catch (SocketException e) {
+        // SocketException is thrown when serverSocket is closed while running accept().
+        if (!isCanceled) {
+          isCanceled = true;
+          e.printStackTrace();
+        }
+      } catch (IOException e) {
+        isCanceled = true;
+        // Log the error.
+        e.printStackTrace();
+      }
+    }
+  }
+}

library/rtsp/src/test/java/com/google/android/exoplayer2/source/rtsp/RtspSessionTimingTest.java

@@ -0,0 +1,62 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.source.rtsp;
+
+import static com.google.common.truth.Truth.assertThat;
+import static org.junit.Assert.assertThrows;
+
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import com.google.android.exoplayer2.C;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+/** Unit test for {@link RtspSessionTiming}. */
+@RunWith(AndroidJUnit4.class)
+public class RtspSessionTimingTest {
+  @Test
+  public void parseTiming_withNowLiveTiming() throws Exception {
+    RtspSessionTiming sessionTiming = RtspSessionTiming.parseTiming("npt=now-");
+    assertThat(sessionTiming.getDurationMs()).isEqualTo(C.TIME_UNSET);
+    assertThat(sessionTiming.isLive()).isTrue();
+  }
+
+  @Test
+  public void parseTiming_withZeroLiveTiming() throws Exception {
+    RtspSessionTiming sessionTiming = RtspSessionTiming.parseTiming("npt=0-");
+    assertThat(sessionTiming.getDurationMs()).isEqualTo(C.TIME_UNSET);
+    assertThat(sessionTiming.isLive()).isTrue();
+  }
+
+  @Test
+  public void parseTiming_withDecimalZeroLiveTiming() throws Exception {
+    RtspSessionTiming sessionTiming = RtspSessionTiming.parseTiming("npt=0.000-");
+    assertThat(sessionTiming.getDurationMs()).isEqualTo(C.TIME_UNSET);
+    assertThat(sessionTiming.isLive()).isTrue();
+  }
+
+  @Test
+  public void parseTiming_withRangeTiming() throws Exception {
+    RtspSessionTiming sessionTiming = RtspSessionTiming.parseTiming("npt=0.000-32.054");
+    assertThat(sessionTiming.getDurationMs()).isEqualTo(32054);
+    assertThat(sessionTiming.isLive()).isFalse();
+  }
+
+  @Test
+  public void parseTiming_withInvalidRangeTiming_throwsIllegalArgumentException() {
+    assertThrows(
+        IllegalArgumentException.class, () -> RtspSessionTiming.parseTiming("npt=10.000-2.054"));
+  }
+}

library/rtsp/src/test/java/com/google/android/exoplayer2/source/rtsp/RtspTrackTimingTest.java

@@ -0,0 +1,93 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.source.rtsp;
+
+import static com.google.common.truth.Truth.assertThat;
+import static org.junit.Assert.assertThrows;
+
+import android.net.Uri;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.ParserException;
+import com.google.common.collect.ImmutableList;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+/** Unit test for {@link RtspTrackTiming}. */
+@RunWith(AndroidJUnit4.class)
+public class RtspTrackTimingTest {
+  @Test
+  public void parseTiming_withSeqNumberAndRtpTime() throws Exception {
+    String rtpInfoString =
+        "url=rtsp://video.example.com/twister/video;seq=12312232;rtptime=78712811";
+
+    ImmutableList<RtspTrackTiming> trackTimingList =
+        RtspTrackTiming.parseTrackTiming(rtpInfoString);
+
+    assertThat(trackTimingList).hasSize(1);
+    RtspTrackTiming trackTiming = trackTimingList.get(0);
+    assertThat(trackTiming.uri).isEqualTo(Uri.parse("rtsp://video.example.com/twister/video"));
+    assertThat(trackTiming.sequenceNumber).isEqualTo(12312232);
+    assertThat(trackTiming.rtpTimestamp).isEqualTo(78712811);
+  }
+
+  @Test
+  public void parseTiming_withSeqNumberOnly() throws Exception {
+    String rtpInfoString =
+        "url=rtsp://foo.com/bar.avi/streamid=0;seq=45102,url=rtsp://foo.com/bar.avi/streamid=1;seq=30211";
+
+    ImmutableList<RtspTrackTiming> trackTimingList =
+        RtspTrackTiming.parseTrackTiming(rtpInfoString);
+
+    assertThat(trackTimingList).hasSize(2);
+    RtspTrackTiming trackTiming = trackTimingList.get(0);
+    assertThat(trackTiming.uri).isEqualTo(Uri.parse("rtsp://foo.com/bar.avi/streamid=0"));
+    assertThat(trackTiming.sequenceNumber).isEqualTo(45102);
+    assertThat(trackTiming.rtpTimestamp).isEqualTo(C.TIME_UNSET);
+    trackTiming = trackTimingList.get(1);
+    assertThat(trackTiming.uri).isEqualTo(Uri.parse("rtsp://foo.com/bar.avi/streamid=1"));
+    assertThat(trackTiming.sequenceNumber).isEqualTo(30211);
+    assertThat(trackTiming.rtpTimestamp).isEqualTo(C.TIME_UNSET);
+  }
+
+  @Test
+  public void parseTiming_withInvalidParameter_throws() {
+    String rtpInfoString = "url=rtsp://video.example.com/twister/video;seq=123abc";
+
+    assertThrows(ParserException.class, () -> RtspTrackTiming.parseTrackTiming(rtpInfoString));
+  }
+
+  @Test
+  public void parseTiming_withInvalidUrl_throws() {
+    String rtpInfoString = "url=video.example.com/twister/video;seq=36192348";
+
+    assertThrows(ParserException.class, () -> RtspTrackTiming.parseTrackTiming(rtpInfoString));
+  }
+
+  @Test
+  public void parseTiming_withNoParameter_throws() {
+    String rtpInfoString = "url=rtsp://video.example.com/twister/video";
+
+    assertThrows(ParserException.class, () -> RtspTrackTiming.parseTrackTiming(rtpInfoString));
+  }
+
+  @Test
+  public void parseTiming_withNoUrl_throws() {
+    String rtpInfoString = "seq=35421887";
+
+    assertThrows(ParserException.class, () -> RtspTrackTiming.parseTrackTiming(rtpInfoString));
+  }
+}

library/rtsp/src/test/java/com/google/android/exoplayer2/source/rtsp/message/RtspHeadersTest.java

@@ -0,0 +1,102 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.source.rtsp.message;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+/** Unit test for {@link RtspHeaders}. */
+@RunWith(AndroidJUnit4.class)
+public final class RtspHeadersTest {
+
+  @Test
+  public void build_withHeaderLines() {
+    RtspHeaders headers =
+        new RtspHeaders.Builder()
+            .addAll(
+                ImmutableList.of(
+                    "Accept: application/sdp ", // Extra space after header value.
+                    "CSeq:3", // No space after colon.
+                    "Content-Length: 707",
+                    "Transport: RTP/AVP;unicast;client_port=65458-65459\r\n"))
+            .build();
+
+    assertThat(headers.get("Accept")).isEqualTo("application/sdp");
+    assertThat(headers.get("CSeq")).isEqualTo("3");
+    assertThat(headers.get("Content-Length")).isEqualTo("707");
+    assertThat(headers.get("Transport")).isEqualTo("RTP/AVP;unicast;client_port=65458-65459");
+  }
+
+  @Test
+  public void build_withHeaderLinesAsMap() {
+    RtspHeaders headers =
+        new RtspHeaders.Builder()
+            .addAll(
+                ImmutableMap.of(
+                    "Accept", " application/sdp ", // Extra space after header value.
+                    "CSeq", "3", // No space after colon.
+                    "Content-Length", "707",
+                    "Transport", "RTP/AVP;unicast;client_port=65458-65459\r\n"))
+            .build();
+
+    assertThat(headers.get("Accept")).isEqualTo("application/sdp");
+    assertThat(headers.get("CSeq")).isEqualTo("3");
+    assertThat(headers.get("Content-Length")).isEqualTo("707");
+    assertThat(headers.get("Transport")).isEqualTo("RTP/AVP;unicast;client_port=65458-65459");
+  }
+
+  @Test
+  public void get_getsHeaderValuesCaseInsensitively() {
+    RtspHeaders headers =
+        new RtspHeaders.Builder()
+            .addAll(
+                ImmutableList.of(
+                    "ACCEPT: application/sdp ", // Extra space after header value.
+                    "Cseq:3", // No space after colon.
+                    "Content-LENGTH: 707",
+                    "transport: RTP/AVP;unicast;client_port=65458-65459\r\n"))
+            .build();
+
+    assertThat(headers.get("Accept")).isEqualTo("application/sdp");
+    assertThat(headers.get("CSeq")).isEqualTo("3");
+    assertThat(headers.get("Content-Length")).isEqualTo("707");
+    assertThat(headers.get("Transport")).isEqualTo("RTP/AVP;unicast;client_port=65458-65459");
+  }
+
+  @Test
+  public void asMap() {
+    RtspHeaders headers =
+        new RtspHeaders.Builder()
+            .addAll(
+                ImmutableList.of(
+                    "Accept: application/sdp ", // Extra space after header value.
+                    "CSeq:3", // No space after colon.
+                    "Content-Length: 707",
+                    "Transport: RTP/AVP;unicast;client_port=65458-65459\r\n"))
+            .build();
+    assertThat(headers.asMap())
+        .containsExactly(
+            "Accept", "application/sdp",
+            "CSeq", "3",
+            "Content-Length", "707",
+            "Transport", "RTP/AVP;unicast;client_port=65458-65459");
+  }
+}

library/rtsp/src/test/java/com/google/android/exoplayer2/source/rtsp/message/RtspMessageUtilTest.java

@@ -0,0 +1,366 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.android.exoplayer2.source.rtsp.message;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import android.net.Uri;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import com.google.common.base.Charsets;
+import com.google.common.collect.ImmutableMap;
+import java.util.Arrays;
+import java.util.List;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+/** Unit test for {@link RtspMessageUtil}. */
+@RunWith(AndroidJUnit4.class)
+public final class RtspMessageUtilTest {
+
+  @Test
+  public void parseRequest_withOptionsRequest_succeeds() {
+    List<String> requestLines =
+        Arrays.asList(
+            "OPTIONS rtsp://localhost:554/foo.bar RTSP/1.0",
+            "CSeq: 2",
+            "User-Agent: LibVLC/3.0.11",
+            "");
+    RtspRequest request = RtspMessageUtil.parseRequest(requestLines);
+
+    assertThat(request.method).isEqualTo(RtspRequest.METHOD_OPTIONS);
+    assertThat(request.headers.asMap())
+        .containsExactly(RtspHeaders.CSEQ, "2", RtspHeaders.USER_AGENT, "LibVLC/3.0.11");
+    assertThat(request.messageBody).isEmpty();
+  }
+
+  @Test
+  public void parseResponse_withOptionsResponse_succeeds() {
+    List<String> responseLines =
+        Arrays.asList(
+            "RTSP/1.0 200 OK",
+            "CSeq: 2",
+            "Public: OPTIONS, DESCRIBE, SETUP, TEARDOWN, PLAY, PAUSE, GET_PARAMETER, SET_PARAMETER",
+            "");
+    RtspResponse response = RtspMessageUtil.parseResponse(responseLines);
+
+    assertThat(response.status).isEqualTo(200);
+    assertThat(response.headers.asMap())
+        .containsExactly(
+            RtspHeaders.CSEQ,
+            "2",
+            RtspHeaders.PUBLIC,
+            "OPTIONS, DESCRIBE, SETUP, TEARDOWN, PLAY, PAUSE, GET_PARAMETER, SET_PARAMETER");
+    assertThat(response.messageBody).isEmpty();
+  }
+
+  @Test
+  public void parseRequest_withDescribeRequest_succeeds() {
+    List<String> requestLines =
+        Arrays.asList(
+            "DESCRIBE rtsp://localhost:554/foo.bar RTSP/1.0",
+            "CSeq: 3",
+            "User-Agent: LibVLC/3.0.11",
+            "Accept: application/sdp",
+            "");
+    RtspRequest request = RtspMessageUtil.parseRequest(requestLines);
+
+    assertThat(request.method).isEqualTo(RtspRequest.METHOD_DESCRIBE);
+    assertThat(request.headers.asMap())
+        .containsExactly(
+            RtspHeaders.CSEQ,
+            "3",
+            RtspHeaders.USER_AGENT,
+            "LibVLC/3.0.11",
+            RtspHeaders.ACCEPT,
+            "application/sdp");
+    assertThat(request.messageBody).isEmpty();
+  }
+
+  @Test
+  public void parseResponse_withDescribeResponse_succeeds() {
+    List<String> responseLines =
+        Arrays.asList(
+            "RTSP/1.0 200 OK",
+            "CSeq: 3",
+            "Content-Base: rtsp://127.0.0.1/test.mkv/",
+            "Content-Type: application/sdp",
+            "Content-Length: 707",
+            "",
+            "v=0",
+            "o=- 1606776316530225 1 IN IP4 192.168.2.176",
+            "i=imax.mkv",
+            "m=video 0 RTP/AVP 96",
+            "a=rtpmap:96 H264/90000",
+            "a=control:track1",
+            "m=audio 0 RTP/AVP 97",
+            "a=rtpmap:97 AC3/48000",
+            "a=control:track2");
+    RtspResponse response = RtspMessageUtil.parseResponse(responseLines);
+
+    assertThat(response.status).isEqualTo(200);
+    assertThat(response.headers.asMap())
+        .containsExactly(
+            RtspHeaders.CSEQ,
+            "3",
+            RtspHeaders.CONTENT_BASE,
+            "rtsp://127.0.0.1/test.mkv/",
+            RtspHeaders.CONTENT_TYPE,
+            "application/sdp",
+            RtspHeaders.CONTENT_LENGTH,
+            "707");
+
+    assertThat(response.messageBody)
+        .isEqualTo(
+            "v=0\r\n"
+                + "o=- 1606776316530225 1 IN IP4 192.168.2.176\r\n"
+                + "i=imax.mkv\r\n"
+                + "m=video 0 RTP/AVP 96\r\n"
+                + "a=rtpmap:96 H264/90000\r\n"
+                + "a=control:track1\r\n"
+                + "m=audio 0 RTP/AVP 97\r\n"
+                + "a=rtpmap:97 AC3/48000\r\n"
+                + "a=control:track2");
+  }
+
+  @Test
+  public void parseRequest_withSetParameterRequest_succeeds() {
+    List<String> requestLines =
+        Arrays.asList(
+            "SET_PARAMETER rtsp://localhost:554/foo.bar RTSP/1.0",
+            "CSeq: 3",
+            "User-Agent: LibVLC/3.0.11",
+            "Content-Length: 20",
+            "Content-Type: text/parameters",
+            "",
+            "param: stuff");
+    RtspRequest request = RtspMessageUtil.parseRequest(requestLines);
+
+    assertThat(request.method).isEqualTo(RtspRequest.METHOD_SET_PARAMETER);
+    assertThat(request.headers.asMap())
+        .containsExactly(
+            RtspHeaders.CSEQ,
+            "3",
+            RtspHeaders.USER_AGENT,
+            "LibVLC/3.0.11",
+            RtspHeaders.CONTENT_LENGTH,
+            "20",
+            RtspHeaders.CONTENT_TYPE,
+            "text/parameters");
+    assertThat(request.messageBody).isEqualTo("param: stuff");
+  }
+
+  @Test
+  public void parseResponse_withGetParameterResponse_succeeds() {
+    List<String> responseLines =
+        Arrays.asList(
+            "RTSP/1.0 200 OK",
+            "CSeq: 431",
+            "Content-Length: 46",
+            "Content-Type: text/parameters",
+            "",
+            "packets_received: 10",
+            "jitter: 0.3838");
+    RtspResponse response = RtspMessageUtil.parseResponse(responseLines);
+
+    assertThat(response.status).isEqualTo(200);
+    assertThat(response.headers.asMap())
+        .containsExactly(
+            RtspHeaders.CSEQ,
+            "431",
+            RtspHeaders.CONTENT_LENGTH,
+            "46",
+            RtspHeaders.CONTENT_TYPE,
+            "text/parameters");
+
+    assertThat(response.messageBody).isEqualTo("packets_received: 10\r\n" + "jitter: 0.3838");
+  }
+
+  @Test
+  public void serialize_setupRequest_succeeds() {
+    RtspRequest request =
+        new RtspRequest(
+            Uri.parse("rtsp://127.0.0.1/test.mkv/track1"),
+            RtspRequest.METHOD_SETUP,
+            new RtspHeaders.Builder()
+                .addAll(
+                    ImmutableMap.of(
+                        RtspHeaders.CSEQ, "4",
+                        RtspHeaders.TRANSPORT, "RTP/AVP;unicast;client_port=65458-65459"))
+                .build(),
+            /* messageBody= */ "");
+    List<String> messageLines = RtspMessageUtil.serializeRequest(request);
+
+    List<String> expectedLines =
+        Arrays.asList(
+            "SETUP rtsp://127.0.0.1/test.mkv/track1 RTSP/1.0",
+            "CSeq: 4",
+            "Transport: RTP/AVP;unicast;client_port=65458-65459",
+            "",
+            "");
+    String expectedRtspMessage =
+        "SETUP rtsp://127.0.0.1/test.mkv/track1 RTSP/1.0\r\n"
+            + "CSeq: 4\r\n"
+            + "Transport: RTP/AVP;unicast;client_port=65458-65459\r\n"
+            + "\r\n";
+
+    assertThat(messageLines).isEqualTo(expectedLines);
+    assertThat(RtspMessageUtil.convertMessageToByteArray(messageLines))
+        .isEqualTo(expectedRtspMessage.getBytes(Charsets.UTF_8));
+  }
+
+  @Test
+  public void serialize_setupResponse_succeeds() {
+    RtspResponse response =
+        new RtspResponse(
+            /* status= */ 200,
+            new RtspHeaders.Builder()
+                .addAll(
+                    ImmutableMap.of(
+                        RtspHeaders.CSEQ,
+                        "4",
+                        RtspHeaders.TRANSPORT,
+                        "RTP/AVP;unicast;client_port=65458-65459;server_port=5354-5355"))
+                .build(),
+            /* messageBody= */ "");
+    List<String> messageLines = RtspMessageUtil.serializeResponse(response);
+
+    List<String> expectedLines =
+        Arrays.asList(
+            "RTSP/1.0 200 OK",
+            "CSeq: 4",
+            "Transport: RTP/AVP;unicast;client_port=65458-65459;server_port=5354-5355",
+            "",
+            "");
+    String expectedRtspMessage =
+        "RTSP/1.0 200 OK\r\n"
+            + "CSeq: 4\r\n"
+            + "Transport: RTP/AVP;unicast;client_port=65458-65459;server_port=5354-5355\r\n"
+            + "\r\n";
+    assertThat(messageLines).isEqualTo(expectedLines);
+    assertThat(RtspMessageUtil.convertMessageToByteArray(messageLines))
+        .isEqualTo(expectedRtspMessage.getBytes(Charsets.UTF_8));
+  }
+
+  @Test
+  public void serialize_describeResponse_succeeds() {
+
+    RtspResponse response =
+        new RtspResponse(
+            /* status= */ 200,
+            new RtspHeaders.Builder()
+                .addAll(
+                    ImmutableMap.of(
+                        RtspHeaders.CSEQ, "4",
+                        RtspHeaders.CONTENT_BASE, "rtsp://127.0.0.1/test.mkv/",
+                        RtspHeaders.CONTENT_TYPE, "application/sdp",
+                        RtspHeaders.CONTENT_LENGTH, "707"))
+                .build(),
+            /* messageBody= */ "v=0\r\n"
+                + "o=- 1606776316530225 1 IN IP4 192.168.2.176\r\n"
+                + "i=test.mkv\r\n"
+                + "m=video 0 RTP/AVP 96\r\n"
+                + "a=rtpmap:96 H264/90000\r\n"
+                + "a=control:track1\r\n"
+                + "m=audio 0 RTP/AVP 97\r\n"
+                + "a=rtpmap:97 AC3/48000\r\n"
+                + "a=control:track2");
+    List<String> messageLines = RtspMessageUtil.serializeResponse(response);
+
+    List<String> expectedLines =
+        Arrays.asList(
+            "RTSP/1.0 200 OK",
+            "CSeq: 4",
+            "Content-Base: rtsp://127.0.0.1/test.mkv/",
+            "Content-Type: application/sdp",
+            "Content-Length: 707",
+            "",
+            "v=0\r\n"
+                + "o=- 1606776316530225 1 IN IP4 192.168.2.176\r\n"
+                + "i=test.mkv\r\n"
+                + "m=video 0 RTP/AVP 96\r\n"
+                + "a=rtpmap:96 H264/90000\r\n"
+                + "a=control:track1\r\n"
+                + "m=audio 0 RTP/AVP 97\r\n"
+                + "a=rtpmap:97 AC3/48000\r\n"
+                + "a=control:track2");
+
+    String expectedRtspMessage =
+        "RTSP/1.0 200 OK\r\n"
+            + "CSeq: 4\r\n"
+            + "Content-Base: rtsp://127.0.0.1/test.mkv/\r\n"
+            + "Content-Type: application/sdp\r\n"
+            + "Content-Length: 707\r\n"
+            + "\r\n"
+            + "v=0\r\n"
+            + "o=- 1606776316530225 1 IN IP4 192.168.2.176\r\n"
+            + "i=test.mkv\r\n"
+            + "m=video 0 RTP/AVP 96\r\n"
+            + "a=rtpmap:96 H264/90000\r\n"
+            + "a=control:track1\r\n"
+            + "m=audio 0 RTP/AVP 97\r\n"
+            + "a=rtpmap:97 AC3/48000\r\n"
+            + "a=control:track2";
+
+    assertThat(messageLines).isEqualTo(expectedLines);
+    assertThat(RtspMessageUtil.convertMessageToByteArray(messageLines))
+        .isEqualTo(expectedRtspMessage.getBytes(Charsets.UTF_8));
+  }
+
+  @Test
+  public void serialize_failedResponse_succeeds() {
+    RtspResponse response =
+        new RtspResponse(
+            /* status= */ 454,
+            new RtspHeaders.Builder().add(RtspHeaders.CSEQ, "4").build(),
+            /* messageBody= */ "");
+    List<String> messageLines = RtspMessageUtil.serializeResponse(response);
+
+    List<String> expectedLines = Arrays.asList("RTSP/1.0 454 Session Not Found", "CSeq: 4", "", "");
+    String expectedRtspMessage = "RTSP/1.0 454 Session Not Found\r\n" + "CSeq: 4\r\n" + "\r\n";
+
+    assertThat(RtspMessageUtil.serializeResponse(response)).isEqualTo(expectedLines);
+    assertThat(RtspMessageUtil.convertMessageToByteArray(messageLines))
+        .isEqualTo(expectedRtspMessage.getBytes(Charsets.UTF_8));
+  }
+
+  @Test
+  public void removeUserInfo_withUserInfo() {
+    Uri uri = Uri.parse("rtsp://user:pass@foo.bar/foo.mkv");
+    assertThat(RtspMessageUtil.removeUserInfo(uri)).isEqualTo(Uri.parse("rtsp://foo.bar/foo.mkv"));
+  }
+
+  @Test
+  public void removeUserInfo_withUserInfoAndPortNumber() {
+    Uri uri = Uri.parse("rtsp://user:pass@foo.bar:5050/foo.mkv");
+    assertThat(RtspMessageUtil.removeUserInfo(uri))
+        .isEqualTo(Uri.parse("rtsp://foo.bar:5050/foo.mkv"));
+  }
+
+  @Test
+  public void removeUserInfo_withEmptyUserInfoAndPortNumber() {
+    Uri uri = Uri.parse("rtsp://@foo.bar:5050/foo.mkv");
+    assertThat(RtspMessageUtil.removeUserInfo(uri))
+        .isEqualTo(Uri.parse("rtsp://foo.bar:5050/foo.mkv"));
+  }
+
+  @Test
+  public void removeUserInfo_withNoUserInfo() {
+    Uri uri = Uri.parse("rtsp://foo.bar:5050/foo.mkv");
+    assertThat(RtspMessageUtil.removeUserInfo(uri))
+        .isEqualTo(Uri.parse("rtsp://foo.bar:5050/foo.mkv"));
+  }
+}

library/rtsp/src/test/java/com/google/android/exoplayer2/source/rtsp/rtp/RtpAc3ReaderTest.java

@@ -0,0 +1,199 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.source.rtsp.rtp;
+
+import static com.google.android.exoplayer2.util.Util.getBytesFromHexString;
+import static com.google.common.truth.Truth.assertThat;
+import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.Mockito.when;
+
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import com.google.android.exoplayer2.Format;
+import com.google.android.exoplayer2.extractor.ExtractorOutput;
+import com.google.android.exoplayer2.source.rtsp.rtp.reader.RtpAc3Reader;
+import com.google.android.exoplayer2.testutil.FakeTrackOutput;
+import com.google.android.exoplayer2.util.MimeTypes;
+import com.google.android.exoplayer2.util.ParsableByteArray;
+import com.google.common.collect.ImmutableMap;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnit;
+import org.mockito.junit.MockitoRule;
+
+/** Unit test for {@link RtpAc3Reader}. */
+@RunWith(AndroidJUnit4.class)
+public final class RtpAc3ReaderTest {
+
+  private final RtpPacket frame1fragment1 =
+      createRtpPacket(
+          /* timestamp= */ 2599168056L,
+          /* sequenceNumber= */ 40289,
+          /* marker= */ false,
+          /* payloadData= */ getBytesFromHexString("02020102"));
+  private final RtpPacket frame1fragment2 =
+      createRtpPacket(
+          /* timestamp= */ 2599168056L,
+          /* sequenceNumber= */ 40290,
+          /* marker= */ true,
+          /* payloadData= */ getBytesFromHexString("03020304"));
+  private final RtpPacket frame2fragment1 =
+      createRtpPacket(
+          /* timestamp= */ 2599169592L,
+          /* sequenceNumber= */ 40292,
+          /* marker= */ false,
+          /* payloadData= */ getBytesFromHexString("02020506"));
+  private final RtpPacket frame2fragment2 =
+      createRtpPacket(
+          /* timestamp= */ 2599169592L,
+          /* sequenceNumber= */ 40293,
+          /* marker= */ true,
+          /* payloadData= */ getBytesFromHexString("03020708"));
+
+  private static final RtpPayloadFormat AC3_FORMAT =
+      new RtpPayloadFormat(
+          new Format.Builder()
+              .setChannelCount(6)
+              .setSampleMimeType(MimeTypes.AUDIO_AC3)
+              .setSampleRate(48_000)
+              .build(),
+          /* rtpPayloadType= */ 97,
+          /* clockRate= */ 48_000,
+          /* fmtpParameters= */ ImmutableMap.of());
+
+  @Rule public final MockitoRule mockito = MockitoJUnit.rule();
+
+  private ParsableByteArray packetData;
+
+  private RtpAc3Reader ac3Reader;
+  private FakeTrackOutput trackOutput;
+  @Mock private ExtractorOutput extractorOutput;
+
+  @Before
+  public void setUp() {
+    packetData = new ParsableByteArray();
+    trackOutput = new FakeTrackOutput(/* deduplicateConsecutiveFormats= */ true);
+    when(extractorOutput.track(anyInt(), anyInt())).thenReturn(trackOutput);
+    ac3Reader = new RtpAc3Reader(AC3_FORMAT);
+    ac3Reader.createTracks(extractorOutput, /* trackId= */ 0);
+  }
+
+  @Test
+  public void consume_allPackets() {
+    ac3Reader.onReceivingFirstPacket(frame1fragment1.timestamp, frame1fragment1.sequenceNumber);
+    packetData.reset(frame1fragment1.payloadData);
+    ac3Reader.consume(
+        packetData,
+        frame1fragment1.timestamp,
+        frame1fragment1.sequenceNumber,
+        /* isFrameBoundary= */ frame1fragment1.marker);
+    packetData.reset(frame1fragment2.payloadData);
+    ac3Reader.consume(
+        packetData,
+        frame1fragment2.timestamp,
+        frame1fragment2.sequenceNumber,
+        /* isFrameBoundary= */ frame1fragment2.marker);
+    packetData.reset(frame2fragment1.payloadData);
+    ac3Reader.consume(
+        packetData,
+        frame2fragment1.timestamp,
+        frame2fragment1.sequenceNumber,
+        /* isFrameBoundary= */ frame2fragment1.marker);
+    packetData.reset(frame2fragment2.payloadData);
+    ac3Reader.consume(
+        packetData,
+        frame2fragment2.timestamp,
+        frame2fragment2.sequenceNumber,
+        /* isFrameBoundary= */ frame2fragment2.marker);
+
+    assertThat(trackOutput.getSampleCount()).isEqualTo(2);
+    assertThat(trackOutput.getSampleData(0)).isEqualTo(getBytesFromHexString("01020304"));
+    assertThat(trackOutput.getSampleTimeUs(0)).isEqualTo(0);
+    assertThat(trackOutput.getSampleData(1)).isEqualTo(getBytesFromHexString("05060708"));
+    assertThat(trackOutput.getSampleTimeUs(1)).isEqualTo(32000);
+  }
+
+  @Test
+  public void consume_fragmentedFrameMissingFirstFragment() {
+    // First packet timing information is transmitted over RTSP, not RTP.
+    ac3Reader.onReceivingFirstPacket(frame1fragment1.timestamp, frame1fragment1.sequenceNumber);
+    packetData.reset(frame1fragment2.payloadData);
+    ac3Reader.consume(
+        packetData,
+        frame1fragment2.timestamp,
+        frame1fragment2.sequenceNumber,
+        /* isFrameBoundary= */ frame1fragment2.marker);
+    packetData.reset(frame2fragment1.payloadData);
+    ac3Reader.consume(
+        packetData,
+        frame2fragment1.timestamp,
+        frame2fragment1.sequenceNumber,
+        /* isFrameBoundary= */ frame2fragment1.marker);
+    packetData.reset(frame2fragment2.payloadData);
+    ac3Reader.consume(
+        packetData,
+        frame2fragment2.timestamp,
+        frame2fragment2.sequenceNumber,
+        /* isFrameBoundary= */ frame2fragment2.marker);
+
+    assertThat(trackOutput.getSampleCount()).isEqualTo(2);
+    assertThat(trackOutput.getSampleData(0)).isEqualTo(getBytesFromHexString("0304"));
+    assertThat(trackOutput.getSampleTimeUs(0)).isEqualTo(0);
+    assertThat(trackOutput.getSampleData(1)).isEqualTo(getBytesFromHexString("05060708"));
+    assertThat(trackOutput.getSampleTimeUs(1)).isEqualTo(32000);
+  }
+
+  @Test
+  public void consume_fragmentedFrameMissingBoundaryFragment() {
+    ac3Reader.onReceivingFirstPacket(frame1fragment1.timestamp, frame1fragment1.sequenceNumber);
+    packetData.reset(frame1fragment1.payloadData);
+    ac3Reader.consume(
+        packetData,
+        frame1fragment1.timestamp,
+        frame1fragment1.sequenceNumber,
+        /* isFrameBoundary= */ frame1fragment1.marker);
+    packetData.reset(frame2fragment1.payloadData);
+    ac3Reader.consume(
+        packetData,
+        frame2fragment1.timestamp,
+        frame2fragment1.sequenceNumber,
+        /* isFrameBoundary= */ frame2fragment1.marker);
+    packetData.reset(frame2fragment2.payloadData);
+    ac3Reader.consume(
+        packetData,
+        frame2fragment2.timestamp,
+        frame2fragment2.sequenceNumber,
+        /* isFrameBoundary= */ frame2fragment2.marker);
+
+    assertThat(trackOutput.getSampleCount()).isEqualTo(2);
+    assertThat(trackOutput.getSampleData(0)).isEqualTo(getBytesFromHexString("0102"));
+    assertThat(trackOutput.getSampleTimeUs(0)).isEqualTo(0);
+    assertThat(trackOutput.getSampleData(1)).isEqualTo(getBytesFromHexString("05060708"));
+    assertThat(trackOutput.getSampleTimeUs(1)).isEqualTo(32000);
+  }
+
+  private static RtpPacket createRtpPacket(
+      long timestamp, int sequenceNumber, boolean marker, byte[] payloadData) {
+    return new RtpPacket.Builder()
+        .setTimestamp((int) timestamp)
+        .setSequenceNumber(sequenceNumber)
+        .setMarker(marker)
+        .setPayloadData(payloadData)
+        .build();
+  }
+}

library/rtsp/src/test/java/com/google/android/exoplayer2/source/rtsp/rtp/RtpPacketReorderingQueueTest.java

@@ -0,0 +1,213 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.android.exoplayer2.source.rtsp.rtp;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import java.util.ArrayList;
+import java.util.List;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+/** Unit tests for {@link RtpPacketReorderingQueue}. */
+@RunWith(AndroidJUnit4.class)
+public class RtpPacketReorderingQueueTest {
+
+  private final RtpPacketReorderingQueue reorderingQueue = new RtpPacketReorderingQueue();
+
+  @Test
+  public void poll_emptyQueue_returnsNull() {
+    assertThat(reorderingQueue.poll(/* cutoffTimestampMs= */ 0)).isNull();
+  }
+
+  @Test
+  public void poll_onlyOnePacketInQueue_returns() {
+    RtpPacket packet = makePacket(/* sequenceNumber= */ 1);
+
+    // Queue after offering: [1].
+    reorderingQueue.offer(packet, /* receivedTimestampMs= */ 0);
+    assertThat(reorderingQueue.poll(/* cutoffTimestampMs= */ 0)).isEqualTo(packet);
+  }
+
+  @Test
+  public void poll_withPacketsEnqueuedInOrder_returnsCorrectPacket() {
+    RtpPacket packet1 = makePacket(/* sequenceNumber= */ 1);
+    RtpPacket packet2 = makePacket(/* sequenceNumber= */ 2);
+    RtpPacket packet3 = makePacket(/* sequenceNumber= */ 3);
+
+    reorderingQueue.offer(packet1, /* receivedTimestampMs= */ 0);
+    reorderingQueue.offer(packet2, /* receivedTimestampMs= */ 0);
+    reorderingQueue.offer(packet3, /* receivedTimestampMs= */ 0);
+
+    assertThat(reorderingQueue.poll(/* cutoffTimestampMs= */ 0)).isEqualTo(packet1);
+    assertThat(reorderingQueue.poll(/* cutoffTimestampMs= */ 0)).isEqualTo(packet2);
+    assertThat(reorderingQueue.poll(/* cutoffTimestampMs= */ 0)).isEqualTo(packet3);
+  }
+
+  @Test
+  public void reset_nonEmptyQueue_resetsQueue() {
+    RtpPacket packet1 = makePacket(/* sequenceNumber= */ 1);
+    RtpPacket packet2 = makePacket(/* sequenceNumber= */ 2);
+
+    reorderingQueue.offer(packet1, /* receivedTimestampMs= */ 0);
+    reorderingQueue.offer(packet2, /* receivedTimestampMs= */ 0);
+    reorderingQueue.reset();
+
+    assertThat(reorderingQueue.poll(/* cutoffTimestampMs= */ 0)).isNull();
+  }
+
+  @Test
+  public void reorder_withPacketArriveOutOfOrderButInTime_returnsPacketsInCorrectOrder() {
+    // The packets arrive in the order of 1, 4, 5, 2, 3, 6. The mis-positioned packets (2, 3)
+    // arrive in time, so the polling order is: 1, null, 2, 3, 4, 5, 6.
+    List<RtpPacket> polledPackets = new ArrayList<>();
+    RtpPacket packet1 = makePacket(/* sequenceNumber= */ 1);
+    RtpPacket packet2 = makePacket(/* sequenceNumber= */ 2);
+    RtpPacket packet3 = makePacket(/* sequenceNumber= */ 3);
+    RtpPacket packet4 = makePacket(/* sequenceNumber= */ 4);
+    RtpPacket packet5 = makePacket(/* sequenceNumber= */ 5);
+    RtpPacket packet6 = makePacket(/* sequenceNumber= */ 6);
+
+    // Offering 1, queue after offering: [1].
+    reorderingQueue.offer(packet1, /* receivedTimestampMs= */ 1);
+    // Offering 4, queue after offering: [1, 4].
+    reorderingQueue.offer(packet4, /* receivedTimestampMs= */ 2);
+    // polling 1, queue after polling: [4].
+    polledPackets.add(reorderingQueue.poll(/* cutoffTimestampMs= */ 0));
+    // Offering 5, queue after offering: [4, 5].
+    reorderingQueue.offer(packet5, /* receivedTimestampMs= */ 3);
+    // Should not poll: still waiting for packet 2, since packet 4 is received at 2, after cutoff.
+    polledPackets.add(reorderingQueue.poll(/* cutoffTimestampMs= */ 1));
+    // Offering 2, queue after offering: [2, 4, 5].
+    reorderingQueue.offer(packet2, /* receivedTimestampMs= */ 4);
+    // polling 2, queue after polling: [4, 5].
+    polledPackets.add(reorderingQueue.poll(/* cutoffTimestampMs= */ 2));
+    // Offering 3, queue after offering: [3, 4, 5].
+    reorderingQueue.offer(packet3, /* receivedTimestampMs= */ 5);
+    // polling 3, queue after polling: [4, 5].
+    polledPackets.add(reorderingQueue.poll(/* cutoffTimestampMs= */ 3));
+    // Offering 6, queue after offering: [4, 5, 6].
+    reorderingQueue.offer(packet6, /* receivedTimestampMs= */ 6);
+    // polling 4, queue after polling: [5, 6].
+    polledPackets.add(reorderingQueue.poll(/* cutoffTimestampMs= */ 4));
+    // polling 5, queue after polling: [6].
+    polledPackets.add(reorderingQueue.poll(/* cutoffTimestampMs= */ 5));
+    // polling 6, queue after polling: [].
+    polledPackets.add(reorderingQueue.poll(/* cutoffTimestampMs= */ 6));
+
+    assertThat(polledPackets)
+        .containsExactly(packet1, null, packet2, packet3, packet4, packet5, packet6)
+        .inOrder();
+  }
+
+  @Test
+  public void
+      reorder_withPacketArriveOutOfOrderMissedDeadline_returnsPacketsWithSequenceNumberJump() {
+    // Packets arrive in order 1, 3, 4, 2. Packet 2 arrives after packet 3 is dequeued, so packet 2
+    // is discarded.
+    List<RtpPacket> polledPackets = new ArrayList<>();
+    RtpPacket packet1 = makePacket(/* sequenceNumber= */ 1);
+    RtpPacket packet2 = makePacket(/* sequenceNumber= */ 2);
+    RtpPacket packet3 = makePacket(/* sequenceNumber= */ 3);
+    RtpPacket packet4 = makePacket(/* sequenceNumber= */ 4);
+
+    // Offering 1, queue after offering: [1].
+    reorderingQueue.offer(packet1, /* receivedTimestampMs= */ 1);
+    // Offering 3, queue after offering: [1, 3].
+    reorderingQueue.offer(packet3, /* receivedTimestampMs= */ 2);
+    // polling 1, queue after polling: [3].
+    polledPackets.add(reorderingQueue.poll(/* cutoffTimestampMs= */ 1));
+    // Queue after offering: [3, 4].
+    reorderingQueue.offer(packet4, /* receivedTimestampMs= */ 3);
+    // Should poll packet 3 (receivedTimestampMs = 2), because 2 hasn't come after the wait.
+    // polling 3, queue after polling: [4].
+    polledPackets.add(reorderingQueue.poll(/* cutoffTimestampMs= */ 2));
+    // Offering 2, queue after offering: [4]. Should not add packet 2: packet 3 is already dequeued.
+    reorderingQueue.offer(packet2, /* receivedTimestampMs= */ 4);
+    // polling 4, queue after polling: [].
+    polledPackets.add(reorderingQueue.poll(/* cutoffTimestampMs= */ 3));
+
+    assertThat(polledPackets).containsExactly(packet1, packet3, packet4).inOrder();
+  }
+
+  @Test
+  public void reorder_withLargerThanAllowedJumpForwardInSequenceNumber_resetsQueue() {
+    RtpPacket packet1 = makePacket(/* sequenceNumber= */ 1);
+    RtpPacket packetWithSequenceNumberJump =
+        makePacket(/* sequenceNumber= */ 10 + RtpPacketReorderingQueue.MAX_SEQUENCE_LEAP_ALLOWED);
+
+    // Offering 1, queue after offering: [1].
+    reorderingQueue.offer(packet1, /* receivedTimestampMs= */ 1);
+
+    // Queueing a packet with a sequence number that creates a shift larger than the allowed maximum
+    // will force reset the queue.
+    reorderingQueue.offer(packetWithSequenceNumberJump, /* receivedTimestampMs= */ 2);
+    assertThat(reorderingQueue.poll(/* cutoffTimestampMs= */ 0))
+        .isEqualTo(packetWithSequenceNumberJump);
+  }
+
+  @Test
+  public void reorder_withLargerThanAllowedJumpInSequenceNumberAndWrapAround_resetsQueue() {
+    RtpPacket packet1 = makePacket(/* sequenceNumber= */ 1);
+    RtpPacket packetWithSequenceNumberJump =
+        makePacket(
+            /* sequenceNumber= */ RtpPacket.MAX_SEQUENCE_NUMBER
+                - RtpPacketReorderingQueue.MAX_SEQUENCE_LEAP_ALLOWED
+                - 10);
+
+    // Offering 1, queue after offering: [1].
+    reorderingQueue.offer(packet1, /* receivedTimestampMs= */ 1);
+    // Queueing a packet with a sequence number that creates a shift larger than the allowed maximum
+    // will force reset the queue.
+    reorderingQueue.offer(packetWithSequenceNumberJump, /* receivedTimestampMs= */ 2);
+
+    assertThat(reorderingQueue.poll(/* cutoffTimestampMs= */ 0))
+        .isEqualTo(packetWithSequenceNumberJump);
+  }
+
+  @Test
+  public void reorder_receivingOutOfOrderPacketWithWrapAround_returnsPacketsInCorrectOrder() {
+    RtpPacket packet2 = makePacket(/* sequenceNumber= */ 2);
+    RtpPacket packet3 = makePacket(/* sequenceNumber= */ 3);
+    RtpPacket packet65000 = makePacket(/* sequenceNumber= */ 65000);
+    RtpPacket packet65001 = makePacket(/* sequenceNumber= */ 65001);
+    RtpPacket packet65002 = makePacket(/* sequenceNumber= */ 65002);
+    RtpPacket packet65003 = makePacket(/* sequenceNumber= */ 65003);
+    RtpPacket packet65004 = makePacket(/* sequenceNumber= */ 65004);
+
+    reorderingQueue.offer(packet65000, /* receivedTimestampMs= */ 1);
+    reorderingQueue.offer(packet65001, /* receivedTimestampMs= */ 2);
+    reorderingQueue.offer(packet65002, /* receivedTimestampMs= */ 3);
+    reorderingQueue.offer(packet65003, /* receivedTimestampMs= */ 4);
+    assertThat(reorderingQueue.poll(/* cutoffTimestampMs= */ 0)).isEqualTo(packet65000);
+    reorderingQueue.offer(packet2, /* receivedTimestampMs= */ 5);
+    reorderingQueue.offer(packet3, /* receivedTimestampMs= */ 6);
+    reorderingQueue.offer(packet65004, /* receivedTimestampMs= */ 7);
+
+    assertThat(reorderingQueue.poll(/* cutoffTimestampMs= */ 0)).isEqualTo(packet65001);
+    assertThat(reorderingQueue.poll(/* cutoffTimestampMs= */ 0)).isEqualTo(packet65002);
+    assertThat(reorderingQueue.poll(/* cutoffTimestampMs= */ 0)).isEqualTo(packet65003);
+    assertThat(reorderingQueue.poll(/* cutoffTimestampMs= */ 0)).isEqualTo(packet65004);
+    assertThat(reorderingQueue.poll(/* cutoffTimestampMs= */ 6)).isEqualTo(packet2);
+    assertThat(reorderingQueue.poll(/* cutoffTimestampMs= */ 0)).isEqualTo(packet3);
+  }
+
+  private static RtpPacket makePacket(int sequenceNumber) {
+    return new RtpPacket.Builder().setSequenceNumber(sequenceNumber).build();
+  }
+}

library/rtsp/src/test/java/com/google/android/exoplayer2/source/rtsp/rtp/RtpPacketTest.java

@@ -0,0 +1,187 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.android.exoplayer2.source.rtsp.rtp;
+
+import static com.google.android.exoplayer2.util.Assertions.checkNotNull;
+import static com.google.android.exoplayer2.util.Util.getBytesFromHexString;
+import static com.google.common.truth.Truth.assertThat;
+
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import com.google.android.exoplayer2.C;
+import java.util.Arrays;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+/** Unit tests for {@link RtpPacket}. */
+@RunWith(AndroidJUnit4.class)
+public final class RtpPacketTest {
+  /*
+    10.. .... = Version: RFC 1889 Version (2)
+    ..0. .... = Padding: False
+    ...0 .... = Extension: False
+    .... 0000 = Contributing source identifiers count: 0
+    1... .... = Marker: True
+    Payload type: DynamicRTP-Type-96 (96)
+    Sequence number: 22159
+    Timestamp: 55166400
+    Synchronization Source identifier: 0xd76ef1a6 (3614372262)
+    Payload: 019fb174427f00006c10c4008962e33ceb5f1fde8ee2d0d9…
+  */
+  private final byte[] rtpData =
+      getBytesFromHexString(
+          "80e0568f0349c5c0d76ef1a6019fb174427f00006c10c4008962e33ceb5f1fde8ee2d0d9b169651024c83b24c3a0f274ea327e2440ae0d3e2ed194beaa2c91edaa5d1e1df7ce30d1ca3726804d2db37765cf3d174338459623bc627c15c687045390a8d702f623a8dbe49e5c7896dbd7105daecb02ce30c0eee324c0c21ed820a0e67344c7a6e10859");
+  private final byte[] rtpPayloadData =
+      Arrays.copyOfRange(rtpData, RtpPacket.MIN_HEADER_SIZE, rtpData.length);
+
+  /*
+   10.. .... = Version: RFC 1889 Version (2)
+   ..0. .... = Padding: False
+   ...0 .... = Extension: False
+   .... 0000 = Contributing source identifiers count: 0
+   1... .... = Marker: True
+   Payload type: DynamicRTP-Type-96 (96)
+   Sequence number: 29234
+   Timestamp: 3688686074
+   Synchronization Source identifier: 0xf5fe62a4 (4127089316)
+   Payload: 419a246c43bffea996000003000003000003000003000003…
+  */
+  private final byte[] rtpDataWithLargeTimestamp =
+      getBytesFromHexString(
+          "80e07232dbdce1faf5fe62a4419a246c43bffea99600000300000300000300000300000300000300000300000300000300000300000300000300000300000300000300000300000300002ce0");
+  private final byte[] rtpWithLargeTimestampPayloadData =
+      Arrays.copyOfRange(
+          rtpDataWithLargeTimestamp, RtpPacket.MIN_HEADER_SIZE, rtpDataWithLargeTimestamp.length);
+
+  @Test
+  public void parseRtpPacket() {
+    RtpPacket packet = checkNotNull(RtpPacket.parse(rtpData, rtpData.length));
+
+    assertThat(packet.version).isEqualTo(RtpPacket.RTP_VERSION);
+    assertThat(packet.padding).isFalse();
+    assertThat(packet.extension).isFalse();
+    assertThat(packet.csrcCount).isEqualTo(0);
+    assertThat(packet.csrc).hasLength(0);
+    assertThat(packet.marker).isTrue();
+    assertThat(packet.payloadType).isEqualTo(96);
+    assertThat(packet.sequenceNumber).isEqualTo(22159);
+    assertThat(packet.timestamp).isEqualTo(55166400);
+    assertThat(packet.ssrc).isEqualTo(0xD76EF1A6);
+    assertThat(packet.payloadData).isEqualTo(rtpPayloadData);
+  }
+
+  @Test
+  public void parseRtpPacketWithLargeTimestamp() {
+    RtpPacket packet =
+        checkNotNull(RtpPacket.parse(rtpDataWithLargeTimestamp, rtpDataWithLargeTimestamp.length));
+
+    assertThat(packet.version).isEqualTo(RtpPacket.RTP_VERSION);
+    assertThat(packet.padding).isFalse();
+    assertThat(packet.extension).isFalse();
+    assertThat(packet.csrcCount).isEqualTo(0);
+    assertThat(packet.csrc).hasLength(0);
+    assertThat(packet.marker).isTrue();
+    assertThat(packet.payloadType).isEqualTo(96);
+    assertThat(packet.sequenceNumber).isEqualTo(29234);
+    assertThat(packet.timestamp).isEqualTo(3688686074L);
+    assertThat(packet.ssrc).isEqualTo(0xf5fe62a4);
+    assertThat(packet.payloadData).isEqualTo(rtpWithLargeTimestampPayloadData);
+  }
+
+  @Test
+  public void writetoBuffer_withProperlySizedBuffer_writesPacket() {
+    int packetByteLength = rtpData.length;
+    RtpPacket packet = checkNotNull(RtpPacket.parse(rtpData, packetByteLength));
+
+    byte[] testBuffer = new byte[packetByteLength];
+    int writtenBytes = packet.writeToBuffer(testBuffer, /* offset= */ 0, packetByteLength);
+
+    assertThat(writtenBytes).isEqualTo(packetByteLength);
+    assertThat(testBuffer).isEqualTo(rtpData);
+  }
+
+  @Test
+  public void writetoBuffer_withBufferTooSmall_doesNotWritePacket() {
+    int packetByteLength = rtpData.length;
+    RtpPacket packet = checkNotNull(RtpPacket.parse(rtpData, packetByteLength));
+
+    byte[] testBuffer = new byte[packetByteLength / 2];
+    int writtenBytes = packet.writeToBuffer(testBuffer, /* offset= */ 0, packetByteLength);
+
+    assertThat(writtenBytes).isEqualTo(C.LENGTH_UNSET);
+  }
+
+  @Test
+  public void writetoBuffer_withProperlySizedBufferButSmallLengthParameter_doesNotWritePacket() {
+    int packetByteLength = rtpData.length;
+    RtpPacket packet = checkNotNull(RtpPacket.parse(rtpData, packetByteLength));
+
+    byte[] testBuffer = new byte[packetByteLength];
+    int writtenBytes = packet.writeToBuffer(testBuffer, /* offset= */ 0, packetByteLength / 2);
+
+    assertThat(writtenBytes).isEqualTo(C.LENGTH_UNSET);
+  }
+
+  @Test
+  public void writetoBuffer_withProperlySizedBufferButNotEnoughSpaceLeft_doesNotWritePacket() {
+    int packetByteLength = rtpData.length;
+    RtpPacket packet = checkNotNull(RtpPacket.parse(rtpData, packetByteLength));
+
+    byte[] testBuffer = new byte[packetByteLength];
+    int writtenBytes =
+        packet.writeToBuffer(testBuffer, /* offset= */ packetByteLength - 1, packetByteLength);
+
+    assertThat(writtenBytes).isEqualTo(C.LENGTH_UNSET);
+  }
+
+  @Test
+  public void buildRtpPacket() {
+    RtpPacket builtPacket =
+        new RtpPacket.Builder()
+            .setPadding(false)
+            .setMarker(true)
+            .setPayloadType((byte) 96)
+            .setSequenceNumber(22159)
+            .setTimestamp(55166400)
+            .setSsrc(0xD76EF1A6)
+            .setPayloadData(rtpPayloadData)
+            .build();
+
+    RtpPacket parsedPacket = checkNotNull(RtpPacket.parse(rtpData, rtpData.length));
+
+    // Test equals function.
+    assertThat(parsedPacket).isEqualTo(builtPacket);
+  }
+
+  @Test
+  public void buildRtpPacketWithLargeTimestamp_matchesPacketData() {
+    RtpPacket builtPacket =
+        new RtpPacket.Builder()
+            .setPadding(false)
+            .setMarker(true)
+            .setPayloadType((byte) 96)
+            .setSequenceNumber(29234)
+            .setTimestamp(3688686074L)
+            .setSsrc(0xf5fe62a4)
+            .setPayloadData(rtpWithLargeTimestampPayloadData)
+            .build();
+
+    int packetSize = RtpPacket.MIN_HEADER_SIZE + builtPacket.payloadData.length;
+    byte[] builtPacketBytes = new byte[packetSize];
+    builtPacket.writeToBuffer(builtPacketBytes, /* offset= */ 0, packetSize);
+    assertThat(builtPacketBytes).isEqualTo(rtpDataWithLargeTimestamp);
+  }
+}

library/rtsp/src/test/java/com/google/android/exoplayer2/source/rtsp/sdp/SessionDescriptionTest.java

@@ -0,0 +1,173 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.android.exoplayer2.source.rtsp.sdp;
+
+import static com.google.android.exoplayer2.source.rtsp.sdp.MediaDescription.MEDIA_TYPE_AUDIO;
+import static com.google.android.exoplayer2.source.rtsp.sdp.MediaDescription.MEDIA_TYPE_VIDEO;
+import static com.google.android.exoplayer2.source.rtsp.sdp.MediaDescription.RTP_AVP_PROFILE;
+import static com.google.android.exoplayer2.source.rtsp.sdp.SessionDescription.ATTR_CONTROL;
+import static com.google.android.exoplayer2.source.rtsp.sdp.SessionDescription.ATTR_FMTP;
+import static com.google.android.exoplayer2.source.rtsp.sdp.SessionDescription.ATTR_RANGE;
+import static com.google.android.exoplayer2.source.rtsp.sdp.SessionDescription.ATTR_RTPMAP;
+import static com.google.android.exoplayer2.source.rtsp.sdp.SessionDescription.ATTR_TOOL;
+import static com.google.android.exoplayer2.source.rtsp.sdp.SessionDescription.ATTR_TYPE;
+import static com.google.common.truth.Truth.assertThat;
+import static org.junit.Assert.assertThrows;
+
+import android.net.Uri;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+/** Unit test for {@link SessionDescription}. */
+@RunWith(AndroidJUnit4.class)
+public class SessionDescriptionTest {
+
+  @Test
+  public void parse_sdpString_succeeds() throws Exception {
+    String testMediaSdpInfo =
+        "v=0\r\n"
+            + "o=MNobody 2890844526 2890842807 IN IP4 192.0.2.46\r\n"
+            + "s=SDP Seminar\r\n"
+            + "i=A Seminar on the session description protocol\r\n"
+            + "u=http://www.example.com/lectures/sdp.ps\r\n"
+            + "e=seminar@example.com (Seminar Management)\r\n"
+            + "c=IN IP4 0.0.0.0\r\n"
+            + "a=control:*\r\n"
+            + "t=2873397496 2873404696\r\n"
+            + "m=audio 3456 RTP/AVP 0\r\n"
+            + "a=control:audio\r\n"
+            + "a=rtpmap:0 PCMU/8000\r\n"
+            + "a=3GPP-Adaption-Support:1\r\n"
+            + "m=video 2232 RTP/AVP 31\r\n"
+            + "a=control:video\r\n"
+            + "a=rtpmap:31 H261/90000\r\n";
+
+    SessionDescription sessionDescription = SessionDescriptionParser.parse(testMediaSdpInfo);
+
+    SessionDescription expectedSession =
+        new SessionDescription.Builder()
+            .setOrigin("MNobody 2890844526 2890842807 IN IP4 192.0.2.46")
+            .setSessionName("SDP Seminar")
+            .setSessionInfo("A Seminar on the session description protocol")
+            .setUri(Uri.parse("http://www.example.com/lectures/sdp.ps"))
+            .setEmailAddress("seminar@example.com (Seminar Management)")
+            .setConnection("IN IP4 0.0.0.0")
+            .setTiming("2873397496 2873404696")
+            .addAttribute(ATTR_CONTROL, "*")
+            .addMediaDescription(
+                new MediaDescription.Builder(MEDIA_TYPE_AUDIO, 3456, RTP_AVP_PROFILE, 0)
+                    .addAttribute(ATTR_CONTROL, "audio")
+                    .addAttribute(ATTR_RTPMAP, "0 PCMU/8000")
+                    .addAttribute("3GPP-Adaption-Support", "1")
+                    .build())
+            .addMediaDescription(
+                new MediaDescription.Builder(MEDIA_TYPE_VIDEO, 2232, RTP_AVP_PROFILE, 31)
+                    .addAttribute(ATTR_CONTROL, "video")
+                    .addAttribute(ATTR_RTPMAP, "31 H261/90000")
+                    .build())
+            .build();
+
+    assertThat(sessionDescription).isEqualTo(expectedSession);
+  }
+
+  @Test
+  public void parse_sdpString2_succeeds() throws Exception {
+    String testMediaSdpInfo =
+        "v=0\r\n"
+            + "o=- 1600785369059721 1 IN IP4 192.168.2.176\r\n"
+            + "s=video+audio, streamed by ExoPlayer\r\n"
+            + "i=test.mkv\r\n"
+            + "t=0 0\r\n"
+            + "a=tool:ExoPlayer\r\n"
+            + "a=type:broadcast\r\n"
+            + "a=control:*\r\n"
+            + "a=range:npt=0-30.102\r\n"
+            + "m=video 0 RTP/AVP 96\r\n"
+            + "c=IN IP4 0.0.0.0\r\n"
+            + "b=AS:500\r\n"
+            + "a=rtpmap:96 H264/90000\r\n"
+            + "a=fmtp:96"
+            + " packetization-mode=1;profile-level-id=64001F;sprop-parameter-sets=Z2QAH6zZQPARabIAAAMACAAAAwGcHjBjLA==,aOvjyyLAAA==\r\n"
+            + "a=control:track1\r\n"
+            + "m=audio 0 RTP/AVP 97\r\n"
+            + "c=IN IP4 0.0.0.0\r\n"
+            + "b=AS:96\r\n"
+            + "a=rtpmap:97 MPEG4-GENERIC/44100\r\n"
+            + "a=fmtp:97"
+            + " streamtype=5;profile-level-id=1;mode=AAC-hbr;sizelength=13;indexlength=3;indexdeltalength=3;config=1208\r\n"
+            + "a=control:track2\r\n";
+
+    SessionDescription sessionDescription = SessionDescriptionParser.parse(testMediaSdpInfo);
+
+    SessionDescription expectedSession =
+        new SessionDescription.Builder()
+            .setOrigin("- 1600785369059721 1 IN IP4 192.168.2.176")
+            .setSessionName("video+audio, streamed by ExoPlayer")
+            .setSessionInfo("test.mkv")
+            .setTiming("0 0")
+            .addAttribute(ATTR_TOOL, "ExoPlayer")
+            .addAttribute(ATTR_TYPE, "broadcast")
+            .addAttribute(ATTR_CONTROL, "*")
+            .addAttribute(ATTR_RANGE, "npt=0-30.102")
+            .addMediaDescription(
+                new MediaDescription.Builder(MEDIA_TYPE_VIDEO, 0, RTP_AVP_PROFILE, 96)
+                    .setConnection("IN IP4 0.0.0.0")
+                    .setBitrate(500_000)
+                    .addAttribute(ATTR_RTPMAP, "96 H264/90000")
+                    .addAttribute(
+                        ATTR_FMTP,
+                        "96 packetization-mode=1;profile-level-id=64001F;sprop-parameter-sets=Z2QAH6zZQPARabIAAAMACAAAAwGcHjBjLA==,aOvjyyLAAA==")
+                    .addAttribute(ATTR_CONTROL, "track1")
+                    .build())
+            .addMediaDescription(
+                new MediaDescription.Builder(MEDIA_TYPE_AUDIO, 0, RTP_AVP_PROFILE, 97)
+                    .setConnection("IN IP4 0.0.0.0")
+                    .setBitrate(96_000)
+                    .addAttribute(ATTR_RTPMAP, "97 MPEG4-GENERIC/44100")
+                    .addAttribute(
+                        ATTR_FMTP,
+                        "97 streamtype=5;profile-level-id=1;mode=AAC-hbr;sizelength=13;indexlength=3;indexdeltalength=3;config=1208")
+                    .addAttribute(ATTR_CONTROL, "track2")
+                    .build())
+            .build();
+
+    assertThat(sessionDescription).isEqualTo(expectedSession);
+  }
+
+  @Test
+  public void buildMediaDescription_withInvalidRtpmapAttribute_throwsIllegalStateException() {
+    assertThrows(
+        IllegalStateException.class,
+        () ->
+            new MediaDescription.Builder(
+                    MEDIA_TYPE_AUDIO, /* port= */ 0, RTP_AVP_PROFILE, /* payloadType= */ 97)
+                .addAttribute(ATTR_RTPMAP, "AF AC3/44100")
+                .build());
+  }
+
+  @Test
+  public void buildMediaDescription_withInvalidRtpmapAttribute2_throwsIllegalStateException() {
+    assertThrows(
+        IllegalStateException.class,
+        () ->
+            new MediaDescription.Builder(
+                    MEDIA_TYPE_AUDIO, /* port= */ 0, RTP_AVP_PROFILE, /* payloadType= */ 97)
+                .addAttribute(ATTR_RTPMAP, "97 AC3/441A0")
+                .build());
+  }
+}