Parse ServiceDescription from DASH manifest

Issue: #4904
PiperOrigin-RevId: 336838559

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

@@ -60,9 +60,10 @@ public final class C {
    */
   public static final int POSITION_UNSET = -1;
 
-  /**
+  /** Represents an unset or unknown rate. */
-   * Represents an unset or unknown length.
+  public static final float RATE_UNSET = -Float.MAX_VALUE;
-   */
+
+  /** Represents an unset or unknown length. */
   public static final int LENGTH_UNSET = -1;
 
   /** Represents an unset or unknown percentage. */

library/dash/src/main/java/com/google/android/exoplayer2/source/dash/manifest/DashManifest.java

@@ -82,6 +82,9 @@ public class DashManifest implements FilterableManifest<DashManifest> {
    */
   @Nullable public final UtcTimingElement utcTiming;
 
+  /** The {@link ServiceDescriptionElement}, or null if not present. */
+  @Nullable public final ServiceDescriptionElement serviceDescription;
+
   /** The location of this manifest, or null if not present. */
   @Nullable public final Uri location;
 
@@ -92,7 +95,7 @@ public class DashManifest implements FilterableManifest<DashManifest> {
 
   /**
    * @deprecated Use {@link #DashManifest(long, long, long, boolean, long, long, long, long,
-   *     ProgramInformation, UtcTimingElement, Uri, List)}.
+   *     ProgramInformation, UtcTimingElement, ServiceDescriptionElement, Uri, List)}.
    */
   @Deprecated
   public DashManifest(
@@ -118,6 +121,7 @@ public class DashManifest implements FilterableManifest<DashManifest> {
         publishTimeMs,
         /* programInformation= */ null,
         utcTiming,
+        /* serviceDescription= */ null,
         location,
         periods);
   }
@@ -133,6 +137,7 @@ public class DashManifest implements FilterableManifest<DashManifest> {
       long publishTimeMs,
       @Nullable ProgramInformation programInformation,
       @Nullable UtcTimingElement utcTiming,
+      @Nullable ServiceDescriptionElement serviceDescription,
       @Nullable Uri location,
       List<Period> periods) {
     this.availabilityStartTimeMs = availabilityStartTimeMs;
@@ -146,6 +151,7 @@ public class DashManifest implements FilterableManifest<DashManifest> {
     this.programInformation = programInformation;
     this.utcTiming = utcTiming;
     this.location = location;
+    this.serviceDescription = serviceDescription;
     this.periods = periods == null ? Collections.emptyList() : periods;
   }
 
@@ -203,6 +209,7 @@ public class DashManifest implements FilterableManifest<DashManifest> {
         publishTimeMs,
         programInformation,
         utcTiming,
+        serviceDescription,
         location,
         copyPeriods);
   }

library/dash/src/main/java/com/google/android/exoplayer2/source/dash/manifest/DashManifestParser.java

@@ -125,6 +125,7 @@ public class DashManifestParser extends DefaultHandler
     ProgramInformation programInformation = null;
     UtcTimingElement utcTiming = null;
     Uri location = null;
+    ServiceDescriptionElement serviceDescription = null;
     long baseUrlAvailabilityTimeOffsetUs = dynamic ? 0 : C.TIME_UNSET;
 
     List<Period> periods = new ArrayList<>();
@@ -146,6 +147,8 @@ public class DashManifestParser extends DefaultHandler
         utcTiming = parseUtcTiming(xpp);
       } else if (XmlPullParserUtil.isStartTag(xpp, "Location")) {
         location = Uri.parse(xpp.nextText());
+      } else if (XmlPullParserUtil.isStartTag(xpp, "ServiceDescription")) {
+        serviceDescription = parseServiceDescription(xpp);
       } else if (XmlPullParserUtil.isStartTag(xpp, "Period") && !seenEarlyAccessPeriod) {
         Pair<Period, Long> periodWithDurationMs =
             parsePeriod(
@@ -199,6 +202,7 @@ public class DashManifestParser extends DefaultHandler
         publishTimeMs,
         programInformation,
         utcTiming,
+        serviceDescription,
         location,
         periods);
   }
@@ -214,6 +218,7 @@ public class DashManifestParser extends DefaultHandler
       long publishTimeMs,
       @Nullable ProgramInformation programInformation,
       @Nullable UtcTimingElement utcTiming,
+      @Nullable ServiceDescriptionElement serviceDescription,
       @Nullable Uri location,
       List<Period> periods) {
     return new DashManifest(
@@ -227,6 +232,7 @@ public class DashManifestParser extends DefaultHandler
         publishTimeMs,
         programInformation,
         utcTiming,
+        serviceDescription,
         location,
         periods);
   }
@@ -241,6 +247,23 @@ public class DashManifestParser extends DefaultHandler
     return new UtcTimingElement(schemeIdUri, value);
   }
 
+  protected ServiceDescriptionElement parseServiceDescription(XmlPullParser xpp)
+      throws XmlPullParserException, IOException {
+    long targetOffsetMs = C.TIME_UNSET;
+    float minPlaybackSpeed = C.RATE_UNSET;
+    float maxPlaybackSpeed = C.RATE_UNSET;
+    do {
+      xpp.next();
+      if (XmlPullParserUtil.isStartTag(xpp, "Latency")) {
+        targetOffsetMs = parseLong(xpp, "target", C.TIME_UNSET);
+      } else if (XmlPullParserUtil.isStartTag(xpp, "PlaybackRate")) {
+        minPlaybackSpeed = parseFloat(xpp, "min", C.RATE_UNSET);
+        maxPlaybackSpeed = parseFloat(xpp, "max", C.RATE_UNSET);
+      }
+    } while (!XmlPullParserUtil.isEndTag(xpp, "ServiceDescription"));
+    return new ServiceDescriptionElement(targetOffsetMs, minPlaybackSpeed, maxPlaybackSpeed);
+  }
+
   protected Pair<Period, Long> parsePeriod(
       XmlPullParser xpp,
       String baseUrl,
@@ -1715,6 +1738,11 @@ public class DashManifestParser extends DefaultHandler
     return value == null ? defaultValue : Long.parseLong(value);
   }
 
+  protected static float parseFloat(XmlPullParser xpp, String name, float defaultValue) {
+    String value = xpp.getAttributeValue(null, name);
+    return value == null ? defaultValue : Float.parseFloat(value);
+  }
+
   protected static String parseString(XmlPullParser xpp, String name, String defaultValue) {
     String value = xpp.getAttributeValue(null, name);
     return value == null ? defaultValue : value;

library/dash/src/main/java/com/google/android/exoplayer2/source/dash/manifest/ServiceDescriptionElement.java

@@ -0,0 +1,46 @@
+/*
+ * 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.dash.manifest;
+
+import com.google.android.exoplayer2.C;
+
+/** Represents a service description element. */
+public final class ServiceDescriptionElement {
+
+  /** The target live offset in milliseconds, or {@link C#TIME_UNSET} if undefined. */
+  public final long targetOffsetMs;
+  /** The minimum playback speed for live speed adjustment, or {@link C#RATE_UNSET} if undefined. */
+  public final float minPlaybackSpeed;
+  /** The maximum playback speed for live speed adjustment, or {@link C#RATE_UNSET} if undefined. */
+  public final float maxPlaybackSpeed;
+
+  /**
+   * Creates a service description element.
+   *
+   * @param targetOffsetMs The target live offset in milliseconds, or {@link C#TIME_UNSET} if
+   *     undefined.
+   * @param minPlaybackSpeed The minimum playback speed for live speed adjustment, or {@link
+   *     C#RATE_UNSET} if undefined.
+   * @param maxPlaybackSpeed The maximum playback speed for live speed adjustment, or {@link
+   *     C#RATE_UNSET} if undefined.
+   */
+  public ServiceDescriptionElement(
+      long targetOffsetMs, float minPlaybackSpeed, float maxPlaybackSpeed) {
+    this.targetOffsetMs = targetOffsetMs;
+    this.minPlaybackSpeed = minPlaybackSpeed;
+    this.maxPlaybackSpeed = maxPlaybackSpeed;
+  }
+}

library/dash/src/test/java/com/google/android/exoplayer2/source/dash/manifest/DashManifestParserTest.java

@@ -57,6 +57,12 @@ public class DashManifestParserTest {
       "media/mpd/sample_mpd_availabilityTimeOffset_segmentTemplate";
   private static final String SAMPLE_MPD_AVAILABILITY_TIME_OFFSET_SEGMENT_LIST =
       "media/mpd/sample_mpd_availabilityTimeOffset_segmentList";
+  private static final String SAMPLE_MPD_SERVICE_DESCRIPTION_LOW_LATENCY =
+      "media/mpd/sample_mpd_service_description_low_latency";
+  private static final String SAMPLE_MPD_SERVICE_DESCRIPTION_LOW_LATENCY_NO_TARGET_LATENCY =
+      "media/mpd/sample_mpd_service_description_low_latency_no_target_latency";
+  private static final String SAMPLE_MPD_SERVICE_DESCRIPTION_LOW_LATENCY_NO_PLAYBACK_RATES =
+      "media/mpd/sample_mpd_service_description_low_latency_no_playback_rates";
 
   private static final String NEXT_TAG_NAME = "Next";
   private static final String NEXT_TAG = "<" + NEXT_TAG_NAME + "/>";
@@ -560,6 +566,71 @@ public class DashManifestParserTest {
     assertThat(getAvailabilityTimeOffsetUs(adaptationSets1.get(0))).isEqualTo(9_999_000);
   }
 
+  @Test
+  public void serviceDescriptionElement_allValuesSet() throws IOException {
+    DashManifestParser parser = new DashManifestParser();
+
+    DashManifest manifest =
+        parser.parse(
+            Uri.parse("https://example.com/test.mpd"),
+            TestUtil.getInputStream(
+                ApplicationProvider.getApplicationContext(),
+                SAMPLE_MPD_SERVICE_DESCRIPTION_LOW_LATENCY));
+
+    assertThat(manifest.serviceDescription).isNotNull();
+    assertThat(manifest.serviceDescription.targetOffsetMs).isEqualTo(20_000);
+    assertThat(manifest.serviceDescription.minPlaybackSpeed).isEqualTo(0.1f);
+    assertThat(manifest.serviceDescription.maxPlaybackSpeed).isEqualTo(99f);
+  }
+
+  @Test
+  public void serviceDescriptionElement_noLatency_isUnset() throws IOException {
+    DashManifestParser parser = new DashManifestParser();
+
+    DashManifest manifest =
+        parser.parse(
+            Uri.parse("https://example.com/test.mpd"),
+            TestUtil.getInputStream(
+                ApplicationProvider.getApplicationContext(),
+                SAMPLE_MPD_SERVICE_DESCRIPTION_LOW_LATENCY_NO_TARGET_LATENCY));
+
+    assertThat(manifest.serviceDescription).isNotNull();
+    assertThat(manifest.serviceDescription.targetOffsetMs).isEqualTo(C.TIME_UNSET);
+    assertThat(manifest.serviceDescription.minPlaybackSpeed).isEqualTo(0.1f);
+    assertThat(manifest.serviceDescription.maxPlaybackSpeed).isEqualTo(99f);
+  }
+
+  @Test
+  public void serviceDescriptionElement_noPlaybackRates_isUnset() throws IOException {
+    DashManifestParser parser = new DashManifestParser();
+
+    DashManifest manifest =
+        parser.parse(
+            Uri.parse("https://example.com/test.mpd"),
+            TestUtil.getInputStream(
+                ApplicationProvider.getApplicationContext(),
+                SAMPLE_MPD_SERVICE_DESCRIPTION_LOW_LATENCY_NO_PLAYBACK_RATES));
+
+    assertThat(manifest.serviceDescription).isNotNull();
+    assertThat(manifest.serviceDescription.targetOffsetMs).isEqualTo(20_000);
+    assertThat(manifest.serviceDescription.minPlaybackSpeed).isEqualTo(C.RATE_UNSET);
+    assertThat(manifest.serviceDescription.maxPlaybackSpeed).isEqualTo(C.RATE_UNSET);
+  }
+
+  @Test
+  public void serviceDescriptionElement_noServiceDescription_isNullInManifest() throws IOException {
+    DashManifestParser parser = new DashManifestParser();
+
+    DashManifest manifest =
+        parser.parse(
+            Uri.parse("https://example.com/test.mpd"),
+            TestUtil.getInputStream(
+                ApplicationProvider.getApplicationContext(),
+                SAMPLE_MPD_AVAILABILITY_TIME_OFFSET_SEGMENT_LIST));
+
+    assertThat(manifest.serviceDescription).isNull();
+  }
+
   private static List<Descriptor> buildCea608AccessibilityDescriptors(String value) {
     return Collections.singletonList(new Descriptor("urn:scte:dash:cc:cea-608:2015", value, null));
   }

library/dash/src/test/java/com/google/android/exoplayer2/source/dash/manifest/DashManifestTest.java

@@ -18,6 +18,7 @@ package com.google.android.exoplayer2.source.dash.manifest;
 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.Format;
 import com.google.android.exoplayer2.offline.StreamKey;
@@ -40,9 +41,13 @@ public class DashManifestTest {
   @Test
   public void copy() {
     Representation[][][] representations = newRepresentations(3, 2, 3);
+    ServiceDescriptionElement serviceDescriptionElement =
+        new ServiceDescriptionElement(
+            /* targetOffsetMs= */ 20, /* minPlaybackSpeed= */ 0.9f, /* maxPlaybackSpeed= */ 1.1f);
     DashManifest sourceManifest =
         newDashManifest(
             10,
+            serviceDescriptionElement,
             newPeriod(
                 "1",
                 1,
@@ -78,6 +83,7 @@ public class DashManifestTest {
     DashManifest expectedManifest =
         newDashManifest(
             10,
+            serviceDescriptionElement,
             newPeriod(
                 "1",
                 1,
@@ -102,6 +108,7 @@ public class DashManifestTest {
     DashManifest sourceManifest =
         newDashManifest(
             10,
+            /* serviceDescription= */ null,
             newPeriod("1", 1, newAdaptationSet(2, representations[0][0])),
             newPeriod("4", 4, newAdaptationSet(5, representations[1][0])));
 
@@ -111,6 +118,7 @@ public class DashManifestTest {
     DashManifest expectedManifest =
         newDashManifest(
             10,
+            /* serviceDescription= */ null,
             newPeriod("1", 1, newAdaptationSet(2, representations[0][0])),
             newPeriod("4", 4, newAdaptationSet(5, representations[1][0])));
     assertManifestEquals(expectedManifest, copyManifest);
@@ -122,6 +130,7 @@ public class DashManifestTest {
     DashManifest sourceManifest =
         newDashManifest(
             10,
+            /* serviceDescription= */ null,
             newPeriod(
                 "1",
                 1,
@@ -151,6 +160,7 @@ public class DashManifestTest {
     DashManifest expectedManifest =
         newDashManifest(
             7,
+            /* serviceDescription= */ null,
             newPeriod(
                 "1",
                 1,
@@ -177,6 +187,7 @@ public class DashManifestTest {
     assertThat(actual.utcTiming).isEqualTo(expected.utcTiming);
     assertThat(actual.location).isEqualTo(expected.location);
     assertThat(actual.getPeriodCount()).isEqualTo(expected.getPeriodCount());
+    assertThat(actual.serviceDescription).isEqualTo(expected.serviceDescription);
     for (int i = 0; i < expected.getPeriodCount(); i++) {
       Period expectedPeriod = expected.getPeriod(i);
       Period actualPeriod = actual.getPeriod(i);
@@ -217,7 +228,8 @@ public class DashManifestTest {
     return Representation.newInstance(/* revisionId= */ 0, FORMAT, /* baseUrl= */ "", SEGMENT_BASE);
   }
 
-  private static DashManifest newDashManifest(int duration, Period... periods) {
+  private static DashManifest newDashManifest(
+      int duration, @Nullable ServiceDescriptionElement serviceDescription, Period... periods) {
     return new DashManifest(
         /* availabilityStartTimeMs= */ 0,
         duration,
@@ -229,6 +241,7 @@ public class DashManifestTest {
         /* publishTimeMs= */ 12345,
         /* programInformation= */ null,
         UTC_TIMING,
+        serviceDescription,
         Uri.EMPTY,
         Arrays.asList(periods));
   }

testdata/src/test/assets/media/mpd/sample_mpd_service_description_low_latency

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<MPD type="static" duration="1s" mediaPresentationDuration="PT1S">
+ <ServiceDescription>
+  <Latency target="20000"/>
+  <PlaybackRate min="0.1" max="99"/>
+ </ServiceDescription>
+ <Period>
+  <AdaptationSet id="0" mimeType="audio/mp4" subsegmentAlignment="true">
+   <Representation id="0" codecs="mp4a.40.2" audioSamplingRate="48000" bandwidth="144000">
+    <BaseURL>https://test.com/0</BaseURL>
+   </Representation>
+  </AdaptationSet>
+ </Period>
+</MPD>

testdata/src/test/assets/media/mpd/sample_mpd_service_description_low_latency_no_playback_rates

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<MPD type="static" duration="1s" mediaPresentationDuration="PT1S">
+ <ServiceDescription>
+  <Latency target="20000"/>
+ </ServiceDescription>
+ <Period>
+  <AdaptationSet id="0" mimeType="audio/mp4" subsegmentAlignment="true">
+   <Representation id="0" codecs="mp4a.40.2" audioSamplingRate="48000" bandwidth="144000">
+    <BaseURL>https://test.com/0</BaseURL>
+   </Representation>
+  </AdaptationSet>
+ </Period>
+</MPD>

testdata/src/test/assets/media/mpd/sample_mpd_service_description_low_latency_no_target_latency

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<MPD type="static" duration="1s" mediaPresentationDuration="PT1S">
+ <ServiceDescription>
+  <PlaybackRate min="0.1" max="99"/>
+ </ServiceDescription>
+ <Period>
+  <AdaptationSet id="0" mimeType="audio/mp4" subsegmentAlignment="true">
+   <Representation id="0" codecs="mp4a.40.2" audioSamplingRate="48000" bandwidth="144000">
+    <BaseURL>https://test.com/0</BaseURL>
+   </Representation>
+  </AdaptationSet>
+ </Period>
+</MPD>