Create HlsMediaChunkExtractor

To be the abstraction to use for integrating with MediaParser.

PiperOrigin-RevId: 316710421

library/hls/src/main/java/com/google/android/exoplayer2/source/hls/BundledHlsMediaChunkExtractor.java

@@ -0,0 +1,101 @@
+/*
+ * 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.hls;
+
+import androidx.annotation.VisibleForTesting;
+import com.google.android.exoplayer2.Format;
+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.mp3.Mp3Extractor;
+import com.google.android.exoplayer2.extractor.mp4.FragmentedMp4Extractor;
+import com.google.android.exoplayer2.extractor.ts.Ac3Extractor;
+import com.google.android.exoplayer2.extractor.ts.Ac4Extractor;
+import com.google.android.exoplayer2.extractor.ts.AdtsExtractor;
+import com.google.android.exoplayer2.extractor.ts.TsExtractor;
+import com.google.android.exoplayer2.util.TimestampAdjuster;
+import java.io.IOException;
+
+/**
+ * {@link HlsMediaChunkExtractor} implementation that uses ExoPlayer app-bundled {@link Extractor
+ * Extractors}.
+ */
+public final class BundledHlsMediaChunkExtractor implements HlsMediaChunkExtractor {
+
+  private static final PositionHolder DUMMY_POSITION_HOLDER = new PositionHolder();
+
+  @VisibleForTesting /* package */ final Extractor extractor;
+  private final Format masterPlaylistFormat;
+  private final TimestampAdjuster timestampAdjuster;
+
+  /**
+   * Creates a new instance.
+   *
+   * @param extractor The underlying {@link Extractor}.
+   * @param masterPlaylistFormat The {@link Format} obtained from the master playlist.
+   * @param timestampAdjuster A {@link TimestampAdjuster} to adjust sample timestamps.
+   */
+  public BundledHlsMediaChunkExtractor(
+      Extractor extractor, Format masterPlaylistFormat, TimestampAdjuster timestampAdjuster) {
+    this.extractor = extractor;
+    this.masterPlaylistFormat = masterPlaylistFormat;
+    this.timestampAdjuster = timestampAdjuster;
+  }
+
+  @Override
+  public void init(ExtractorOutput extractorOutput) {
+    extractor.init(extractorOutput);
+  }
+
+  @Override
+  public boolean read(ExtractorInput extractorInput) throws IOException {
+    return extractor.read(extractorInput, DUMMY_POSITION_HOLDER) == Extractor.RESULT_CONTINUE;
+  }
+
+  @Override
+  public boolean isPackedAudioExtractor() {
+    return extractor instanceof AdtsExtractor
+        || extractor instanceof Ac3Extractor
+        || extractor instanceof Ac4Extractor
+        || extractor instanceof Mp3Extractor;
+  }
+
+  @Override
+  public HlsMediaChunkExtractor reuseOrRecreate() {
+    if (extractor instanceof TsExtractor || extractor instanceof FragmentedMp4Extractor) {
+      // We can reuse this instance.
+      return this;
+    }
+    Extractor newExtractorInstance;
+    if (extractor instanceof WebvttExtractor) {
+      newExtractorInstance = new WebvttExtractor(masterPlaylistFormat.language, timestampAdjuster);
+    } else if (extractor instanceof AdtsExtractor) {
+      newExtractorInstance = new AdtsExtractor();
+    } else if (extractor instanceof Ac3Extractor) {
+      newExtractorInstance = new Ac3Extractor();
+    } else if (extractor instanceof Ac4Extractor) {
+      newExtractorInstance = new Ac4Extractor();
+    } else if (extractor instanceof Mp3Extractor) {
+      newExtractorInstance = new Mp3Extractor();
+    } else {
+      throw new IllegalStateException(
+          "Unexpected previousExtractor type: " + extractor.getClass().getSimpleName());
+    }
+    return new BundledHlsMediaChunkExtractor(
+        newExtractorInstance, masterPlaylistFormat, timestampAdjuster);
+  }
+}

library/hls/src/main/java/com/google/android/exoplayer2/source/hls/DefaultHlsExtractorFactory.java

@@ -88,8 +88,8 @@ public final class DefaultHlsExtractorFactory implements HlsExtractorFactory {
   }
 
   @Override
-  public Result createExtractor(
+  public BundledHlsMediaChunkExtractor createExtractor(
-      @Nullable Extractor previousExtractor,
+      @Nullable HlsMediaChunkExtractor previousExtractor,
       Uri uri,
       Format format,
       @Nullable List<Format> muxedCaptionFormats,
@@ -97,22 +97,6 @@ public final class DefaultHlsExtractorFactory implements HlsExtractorFactory {
       Map<String, List<String>> responseHeaders,
       ExtractorInput extractorInput)
       throws IOException {
-
-    if (previousExtractor != null) {
-      // An extractor has already been successfully used. Return one of the same type.
-      if (isReusable(previousExtractor)) {
-        return buildResult(previousExtractor);
-      } else {
-        @Nullable
-        Result result =
-            buildResultForSameExtractorType(previousExtractor, format, timestampAdjuster);
-        if (result == null) {
-          throw new IllegalArgumentException(
-              "Unexpected previousExtractor type: " + previousExtractor.getClass().getSimpleName());
-        }
-      }
-    }
-
     @FileTypes.Type
     int formatInferredFileType = FileTypes.inferFileTypeFromMimeType(format.sampleMimeType);
     @FileTypes.Type
@@ -139,14 +123,15 @@ public final class DefaultHlsExtractorFactory implements HlsExtractorFactory {
           checkNotNull(
               createExtractorByFileType(fileType, format, muxedCaptionFormats, timestampAdjuster));
       if (sniffQuietly(extractor, extractorInput)) {
-        return buildResult(extractor);
+        return new BundledHlsMediaChunkExtractor(extractor, format, timestampAdjuster);
       }
       if (fileType == FileTypes.TS) {
         fallBackExtractor = extractor;
       }
     }
 
-    return buildResult(checkNotNull(fallBackExtractor));
+    return new BundledHlsMediaChunkExtractor(
+        checkNotNull(fallBackExtractor), format, timestampAdjuster);
   }
 
   private static void addFileTypeIfNotPresent(
@@ -257,34 +242,6 @@ public final class DefaultHlsExtractorFactory implements HlsExtractorFactory {
     return false;
   }
 
-  @Nullable
-  private static Result buildResultForSameExtractorType(
-      Extractor previousExtractor, Format format, TimestampAdjuster timestampAdjuster) {
-    if (previousExtractor instanceof WebvttExtractor) {
-      return buildResult(new WebvttExtractor(format.language, timestampAdjuster));
-    } else if (previousExtractor instanceof AdtsExtractor) {
-      return buildResult(new AdtsExtractor());
-    } else if (previousExtractor instanceof Ac3Extractor) {
-      return buildResult(new Ac3Extractor());
-    } else if (previousExtractor instanceof Ac4Extractor) {
-      return buildResult(new Ac4Extractor());
-    } else if (previousExtractor instanceof Mp3Extractor) {
-      return buildResult(new Mp3Extractor());
-    } else {
-      return null;
-    }
-  }
-
-  private static Result buildResult(Extractor extractor) {
-    return new Result(
-        extractor,
-        extractor instanceof AdtsExtractor
-            || extractor instanceof Ac3Extractor
-            || extractor instanceof Ac4Extractor
-            || extractor instanceof Mp3Extractor,
-        isReusable(extractor));
-  }
-
   private static boolean sniffQuietly(Extractor extractor, ExtractorInput input)
       throws IOException {
     boolean result = false;
@@ -297,9 +254,4 @@ public final class DefaultHlsExtractorFactory implements HlsExtractorFactory {
     }
     return result;
   }
-
-  private static boolean isReusable(Extractor previousExtractor) {
-    return previousExtractor instanceof TsExtractor
-        || previousExtractor instanceof FragmentedMp4Extractor;
-  }
 }

library/hls/src/main/java/com/google/android/exoplayer2/source/hls/HlsExtractorFactory.java

@@ -31,33 +31,6 @@ import java.util.Map;
  */
 public interface HlsExtractorFactory {
 
-  /** Holds an {@link Extractor} and associated parameters. */
-  final class Result {
-
-    /** The created extractor; */
-    public final Extractor extractor;
-    /** Whether the segments for which {@link #extractor} is created are packed audio segments. */
-    public final boolean isPackedAudioExtractor;
-    /**
-     * Whether {@link #extractor} may be reused for following continuous (no immediately preceding
-     * discontinuities) segments of the same variant.
-     */
-    public final boolean isReusable;
-
-    /**
-     * Creates a result.
-     *
-     * @param extractor See {@link #extractor}.
-     * @param isPackedAudioExtractor See {@link #isPackedAudioExtractor}.
-     * @param isReusable See {@link #isReusable}.
-     */
-    public Result(Extractor extractor, boolean isPackedAudioExtractor, boolean isReusable) {
-      this.extractor = extractor;
-      this.isPackedAudioExtractor = isPackedAudioExtractor;
-      this.isReusable = isReusable;
-    }
-  }
-
   HlsExtractorFactory DEFAULT = new DefaultHlsExtractorFactory();
 
   /**
@@ -76,11 +49,11 @@ public interface HlsExtractorFactory {
    * @param sniffingExtractorInput The first extractor input that will be passed to the returned
    *     extractor's {@link Extractor#read(ExtractorInput, PositionHolder)}. Must only be used to
    *     call {@link Extractor#sniff(ExtractorInput)}.
-   * @return A {@link Result}.
+   * @return An {@link HlsMediaChunkExtractor}.
    * @throws IOException If an I/O error is encountered while sniffing.
    */
-  Result createExtractor(
+  HlsMediaChunkExtractor createExtractor(
-      @Nullable Extractor previousExtractor,
+      @Nullable HlsMediaChunkExtractor previousExtractor,
       Uri uri,
       Format format,
       @Nullable List<Format> muxedCaptionFormats,

library/hls/src/main/java/com/google/android/exoplayer2/source/hls/HlsMediaChunk.java

@@ -21,9 +21,7 @@ import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.drm.DrmInitData;
 import com.google.android.exoplayer2.extractor.DefaultExtractorInput;
-import com.google.android.exoplayer2.extractor.Extractor;
 import com.google.android.exoplayer2.extractor.ExtractorInput;
-import com.google.android.exoplayer2.extractor.PositionHolder;
 import com.google.android.exoplayer2.metadata.Metadata;
 import com.google.android.exoplayer2.metadata.id3.Id3Decoder;
 import com.google.android.exoplayer2.metadata.id3.PrivFrame;
@@ -56,8 +54,8 @@ import org.checkerframework.checker.nullness.qual.RequiresNonNull;
   /**
    * Creates a new instance.
    *
-   * @param extractorFactory A {@link HlsExtractorFactory} from which the HLS media chunk extractor
+   * @param extractorFactory A {@link HlsExtractorFactory} from which the {@link
-   *     is obtained.
+   *     HlsMediaChunkExtractor} is obtained.
    * @param dataSource The source from which the data should be loaded.
    * @param format The chunk format.
    * @param startOfPlaylistInPeriodUs The position of the playlist in the period in microseconds.
@@ -130,7 +128,7 @@ import org.checkerframework.checker.nullness.qual.RequiresNonNull;
     int discontinuitySequenceNumber =
         mediaPlaylist.discontinuitySequence + mediaSegment.relativeDiscontinuitySequence;
 
-    @Nullable Extractor previousExtractor = null;
+    @Nullable HlsMediaChunkExtractor previousExtractor = null;
     Id3Decoder id3Decoder;
     ParsableByteArray scratchId3Data;
     boolean shouldSpliceIn;
@@ -147,8 +145,7 @@ import org.checkerframework.checker.nullness.qual.RequiresNonNull;
         sampleQueueDiscardFromIndices = previousChunk.sampleQueueDiscardFromIndices;
       }
       previousExtractor =
-          previousChunk.isExtractorReusable
+          previousChunk.discontinuitySequenceNumber == discontinuitySequenceNumber
-                  && previousChunk.discontinuitySequenceNumber == discontinuitySequenceNumber
                   && !shouldSpliceIn
               ? previousChunk.extractor
               : null;
@@ -188,7 +185,6 @@ import org.checkerframework.checker.nullness.qual.RequiresNonNull;
 
   public static final String PRIV_TIMESTAMP_FRAME_OWNER =
       "com.apple.streaming.transportStreamTimestamp";
-  private static final PositionHolder DUMMY_POSITION_HOLDER = new PositionHolder();
 
   private static final AtomicInteger uidSource = new AtomicInteger();
 
@@ -207,7 +203,7 @@ import org.checkerframework.checker.nullness.qual.RequiresNonNull;
 
   @Nullable private final DataSource initDataSource;
   @Nullable private final DataSpec initDataSpec;
-  @Nullable private final Extractor previousExtractor;
+  @Nullable private final HlsMediaChunkExtractor previousExtractor;
 
   private final boolean isMasterTimestampSource;
   private final boolean hasGapTag;
@@ -221,8 +217,7 @@ import org.checkerframework.checker.nullness.qual.RequiresNonNull;
   private final boolean initSegmentEncrypted;
   private final boolean shouldSpliceIn;
 
-  private @MonotonicNonNull Extractor extractor;
+  private @MonotonicNonNull HlsMediaChunkExtractor extractor;
-  private boolean isExtractorReusable;
   private @MonotonicNonNull HlsSampleStreamWrapper output;
   // nextLoadPosition refers to the init segment if initDataLoadRequired is true.
   // Otherwise, nextLoadPosition refers to the media segment.
@@ -253,7 +248,7 @@ import org.checkerframework.checker.nullness.qual.RequiresNonNull;
       boolean isMasterTimestampSource,
       TimestampAdjuster timestampAdjuster,
       @Nullable DrmInitData drmInitData,
-      @Nullable Extractor previousExtractor,
+      @Nullable HlsMediaChunkExtractor previousExtractor,
       Id3Decoder id3Decoder,
       ParsableByteArray scratchId3Data,
       boolean shouldSpliceIn,
@@ -340,9 +335,8 @@ import org.checkerframework.checker.nullness.qual.RequiresNonNull;
     // output == null means init() hasn't been called.
     Assertions.checkNotNull(output);
     if (extractor == null && previousExtractor != null) {
-      extractor = previousExtractor;
+      extractor = previousExtractor.reuseOrRecreate();
-      isExtractorReusable = true;
+      initDataLoadRequired = extractor != previousExtractor;
-      initDataLoadRequired = false;
     }
     maybeLoadInitData();
     if (!loadCanceled) {
@@ -410,10 +404,7 @@ import org.checkerframework.checker.nullness.qual.RequiresNonNull;
         input.skipFully(nextLoadPosition);
       }
       try {
-        int result = Extractor.RESULT_CONTINUE;
+        while (!loadCanceled && extractor.read(input)) {}
-        while (result == Extractor.RESULT_CONTINUE && !loadCanceled) {
-          result = extractor.read(input, DUMMY_POSITION_HOLDER);
-        }
       } finally {
         nextLoadPosition = (int) (input.getPosition() - dataSpec.position);
       }
@@ -434,7 +425,7 @@ import org.checkerframework.checker.nullness.qual.RequiresNonNull;
       long id3Timestamp = peekId3PrivTimestamp(extractorInput);
       extractorInput.resetPeekPosition();
 
-      HlsExtractorFactory.Result result =
+      extractor =
           extractorFactory.createExtractor(
               previousExtractor,
               dataSpec.uri,
@@ -443,9 +434,7 @@ import org.checkerframework.checker.nullness.qual.RequiresNonNull;
               timestampAdjuster,
               dataSource.getResponseHeaders(),
               extractorInput);
-      extractor = result.extractor;
+      if (extractor.isPackedAudioExtractor()) {
-      isExtractorReusable = result.isReusable;
-      if (result.isPackedAudioExtractor) {
         output.setSampleOffsetUs(
             id3Timestamp != C.TIME_UNSET
                 ? timestampAdjuster.adjustTsTimestamp(id3Timestamp)

library/hls/src/main/java/com/google/android/exoplayer2/source/hls/HlsMediaChunkExtractor.java

@@ -0,0 +1,59 @@
+/*
+ * 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.hls;
+
+import com.google.android.exoplayer2.Format;
+import com.google.android.exoplayer2.extractor.ExtractorInput;
+import com.google.android.exoplayer2.extractor.ExtractorOutput;
+import java.io.IOException;
+
+/** Extracts samples and track {@link Format Formats} from {@link HlsMediaChunk HlsMediaChunks}. */
+public interface HlsMediaChunkExtractor {
+
+  /**
+   * Initializes the extractor with an {@link ExtractorOutput}. Called at most once.
+   *
+   * @param extractorOutput An {@link ExtractorOutput} to receive extracted data.
+   */
+  void init(ExtractorOutput extractorOutput);
+
+  /**
+   * Extracts data read from a provided {@link ExtractorInput}. Must not be called before {@link
+   * #init(ExtractorOutput)}.
+   *
+   * <p>A single call to this method will block until some progress has been made, but will not
+   * block for longer than this. Hence each call will consume only a small amount of input data.
+   *
+   * <p>When this method throws an {@link IOException}, extraction may continue by providing an
+   * {@link ExtractorInput} with an unchanged {@link ExtractorInput#getPosition() read position} to
+   * a subsequent call to this method.
+   *
+   * @param extractorInput The input to read from.
+   * @return Whether there is any data left to extract. Returns false if the end of input has been
+   *     reached.
+   * @throws IOException If an error occurred reading from or parsing the input.
+   */
+  boolean read(ExtractorInput extractorInput) throws IOException;
+
+  /** Returns whether this is a packed audio extractor, as defined in RFC 8216, Section 3.4. */
+  boolean isPackedAudioExtractor();
+
+  /**
+   * If this instance can be used for extracting multiple continuous segments, returns itself.
+   * Otherwise, returns a new instance for extracting the same type of media.
+   */
+  HlsMediaChunkExtractor reuseOrRecreate();
+}

library/hls/src/test/java/com/google/android/exoplayer2/source/hls/DefaultHlsExtractorFactoryTest.java

@@ -22,10 +22,8 @@ import androidx.test.core.app.ApplicationProvider;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.extractor.DefaultExtractorsFactory;
-import com.google.android.exoplayer2.extractor.Extractor;
 import com.google.android.exoplayer2.extractor.ExtractorInput;
 import com.google.android.exoplayer2.extractor.mp3.Mp3Extractor;
-import com.google.android.exoplayer2.extractor.mp4.FragmentedMp4Extractor;
 import com.google.android.exoplayer2.extractor.ts.Ac3Extractor;
 import com.google.android.exoplayer2.extractor.ts.TsExtractor;
 import com.google.android.exoplayer2.testutil.FakeExtractorInput;
@@ -44,7 +42,6 @@ import org.junit.runner.RunWith;
 @RunWith(AndroidJUnit4.class)
 public class DefaultHlsExtractorFactoryTest {
 
-  private Extractor fMp4Extractor;
   private Uri tsUri;
   private Format webVttFormat;
   private TimestampAdjuster timestampAdjuster;
@@ -52,7 +49,6 @@ public class DefaultHlsExtractorFactoryTest {
 
   @Before
   public void setUp() {
-    fMp4Extractor = new FragmentedMp4Extractor();
     tsUri = Uri.parse("http://path/filename.ts");
     webVttFormat = new Format.Builder().setSampleMimeType(MimeTypes.TEXT_VTT).build();
     timestampAdjuster = new TimestampAdjuster(/* firstSampleTimestampUs= */ 0);
@@ -60,24 +56,6 @@ public class DefaultHlsExtractorFactoryTest {
     ac3ResponseHeaders.put("Content-Type", Collections.singletonList(MimeTypes.AUDIO_AC3));
   }
 
-  @Test
-  public void createExtractor_withPreviousExtractor_returnsSameExtractorType() throws Exception {
-    ExtractorInput extractorInput = new FakeExtractorInput.Builder().build();
-
-    HlsExtractorFactory.Result result =
-        new DefaultHlsExtractorFactory()
-            .createExtractor(
-                /* previousExtractor= */ fMp4Extractor,
-                tsUri,
-                webVttFormat,
-                /* muxedCaptionFormats= */ null,
-                timestampAdjuster,
-                ac3ResponseHeaders,
-                extractorInput);
-
-    assertThat(result.extractor.getClass()).isEqualTo(FragmentedMp4Extractor.class);
-  }
-
   @Test
   public void createExtractor_withFileTypeInFormat_returnsExtractorMatchingFormat()
       throws Exception {
@@ -88,7 +66,7 @@ public class DefaultHlsExtractorFactoryTest {
                     ApplicationProvider.getApplicationContext(), "webvtt/typical"))
             .build();
 
-    HlsExtractorFactory.Result result =
+    BundledHlsMediaChunkExtractor result =
         new DefaultHlsExtractorFactory()
             .createExtractor(
                 /* previousExtractor= */ null,
@@ -112,7 +90,7 @@ public class DefaultHlsExtractorFactoryTest {
                 TestUtil.getByteArray(ApplicationProvider.getApplicationContext(), "ts/sample.ac3"))
             .build();
 
-    HlsExtractorFactory.Result result =
+    BundledHlsMediaChunkExtractor result =
         new DefaultHlsExtractorFactory()
             .createExtractor(
                 /* previousExtractor= */ null,
@@ -135,7 +113,7 @@ public class DefaultHlsExtractorFactoryTest {
                     ApplicationProvider.getApplicationContext(), "ts/sample_ac3.ts"))
             .build();
 
-    HlsExtractorFactory.Result result =
+    BundledHlsMediaChunkExtractor result =
         new DefaultHlsExtractorFactory()
             .createExtractor(
                 /* previousExtractor= */ null,
@@ -159,7 +137,7 @@ public class DefaultHlsExtractorFactoryTest {
                     ApplicationProvider.getApplicationContext(), "mp3/bear-id3.mp3"))
             .build();
 
-    HlsExtractorFactory.Result result =
+    BundledHlsMediaChunkExtractor result =
         new DefaultHlsExtractorFactory()
             .createExtractor(
                 /* previousExtractor= */ null,
@@ -177,7 +155,7 @@ public class DefaultHlsExtractorFactoryTest {
   public void createExtractor_withNoMatchingExtractor_fallsBackOnTsExtractor() throws Exception {
     ExtractorInput emptyExtractorInput = new FakeExtractorInput.Builder().build();
 
-    HlsExtractorFactory.Result result =
+    BundledHlsMediaChunkExtractor result =
         new DefaultHlsExtractorFactory()
             .createExtractor(
                 /* previousExtractor= */ null,