Send downStreamFormatChanged notification for embedded streams.

This allows listeners to get notified of any change to the embedded tracks.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=181969023

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

@@ -46,6 +46,7 @@ public class ChunkSampleStream<T extends ChunkSource> implements SampleStream, S
   public final int primaryTrackType;
 
   private final int[] embeddedTrackTypes;
+  private final Format[] embeddedTrackFormats;
   private final boolean[] embeddedTracksSelected;
   private final T chunkSource;
   private final SequenceableLoader.Callback<ChunkSampleStream<T>> callback;
@@ -65,9 +66,10 @@ public class ChunkSampleStream<T extends ChunkSource> implements SampleStream, S
   /* package */ boolean loadingFinished;
 
   /**
-   * @param primaryTrackType The type of the primary track. One of the {@link C}
-   *     {@code TRACK_TYPE_*} constants.
+   * @param primaryTrackType The type of the primary track. One of the {@link C} {@code
+   *     TRACK_TYPE_*} constants.
    * @param embeddedTrackTypes The types of any embedded tracks, or null.
+   * @param embeddedTrackFormats The formats of the embedded tracks, or null.
    * @param chunkSource A {@link ChunkSource} from which chunks to load are obtained.
    * @param callback An {@link Callback} for the stream.
    * @param allocator An {@link Allocator} from which allocations can be obtained.
@@ -76,11 +78,19 @@ public class ChunkSampleStream<T extends ChunkSource> implements SampleStream, S
    *     before propagating an error.
    * @param eventDispatcher A dispatcher to notify of events.
    */
-  public ChunkSampleStream(int primaryTrackType, int[] embeddedTrackTypes, T chunkSource,
-      Callback<ChunkSampleStream<T>> callback, Allocator allocator, long positionUs,
-      int minLoadableRetryCount, EventDispatcher eventDispatcher) {
+  public ChunkSampleStream(
+      int primaryTrackType,
+      int[] embeddedTrackTypes,
+      Format[] embeddedTrackFormats,
+      T chunkSource,
+      Callback<ChunkSampleStream<T>> callback,
+      Allocator allocator,
+      long positionUs,
+      int minLoadableRetryCount,
+      EventDispatcher eventDispatcher) {
     this.primaryTrackType = primaryTrackType;
     this.embeddedTrackTypes = embeddedTrackTypes;
+    this.embeddedTrackFormats = embeddedTrackFormats;
     this.chunkSource = chunkSource;
     this.callback = callback;
     this.eventDispatcher = eventDispatcher;
@@ -555,6 +565,8 @@ public class ChunkSampleStream<T extends ChunkSource> implements SampleStream, S
     private final SampleQueue sampleQueue;
     private final int index;
 
+    private boolean formatNotificationSent;
+
     public EmbeddedSampleStream(ChunkSampleStream<T> parent, SampleQueue sampleQueue, int index) {
       this.parent = parent;
       this.sampleQueue = sampleQueue;
@@ -568,12 +580,19 @@ public class ChunkSampleStream<T extends ChunkSource> implements SampleStream, S
 
     @Override
     public int skipData(long positionUs) {
+      int skipCount;
       if (loadingFinished && positionUs > sampleQueue.getLargestQueuedTimestampUs()) {
-        return sampleQueue.advanceToEnd();
+        skipCount = sampleQueue.advanceToEnd();
       } else {
-        int skipCount = sampleQueue.advanceTo(positionUs, true, true);
-        return skipCount == SampleQueue.ADVANCE_FAILED ? 0 : skipCount;
+        skipCount = sampleQueue.advanceTo(positionUs, true, true);
+        if (skipCount == SampleQueue.ADVANCE_FAILED) {
+          skipCount = 0;
+        }
+      }
+      if (skipCount > 0) {
+        maybeNotifyTrackFormatChanged();
       }
+      return skipCount;
     }
 
     @Override
@@ -587,8 +606,13 @@ public class ChunkSampleStream<T extends ChunkSource> implements SampleStream, S
       if (isPendingReset()) {
         return C.RESULT_NOTHING_READ;
       }
-      return sampleQueue.read(formatHolder, buffer, formatRequired, loadingFinished,
-          lastSeekPositionUs);
+      int result =
+          sampleQueue.read(
+              formatHolder, buffer, formatRequired, loadingFinished, lastSeekPositionUs);
+      if (result == C.RESULT_BUFFER_READ) {
+        maybeNotifyTrackFormatChanged();
+      }
+      return result;
     }
 
     public void release() {
@@ -596,6 +620,17 @@ public class ChunkSampleStream<T extends ChunkSource> implements SampleStream, S
       embeddedTracksSelected[index] = false;
     }
 
+    private void maybeNotifyTrackFormatChanged() {
+      if (!formatNotificationSent) {
+        eventDispatcher.downstreamFormatChanged(
+            embeddedTrackTypes[index],
+            embeddedTrackFormats[index],
+            C.SELECTION_REASON_UNKNOWN,
+            /* trackSelectionData= */ null,
+            lastSeekPositionUs);
+        formatNotificationSent = true;
+      }
+    }
   }
 
 }

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

@@ -436,26 +436,33 @@ import java.util.Map;
       }
 
       AdaptationSet firstAdaptationSet = adaptationSets.get(adaptationSetIndices[0]);
-      int primaryTrackGroupIndex = trackGroupCount;
-      boolean hasEventMessageTrack = primaryGroupHasEventMessageTrackFlags[i];
-      boolean hasCea608Track = primaryGroupHasCea608TrackFlags[i];
-
-      trackGroups[trackGroupCount] = new TrackGroup(formats);
-      trackGroupInfos[trackGroupCount++] = TrackGroupInfo.primaryTrack(firstAdaptationSet.type,
-          adaptationSetIndices, primaryTrackGroupIndex, hasEventMessageTrack, hasCea608Track);
-      if (hasEventMessageTrack) {
+      int primaryTrackGroupIndex = trackGroupCount++;
+      int eventMessageTrackGroupIndex =
+          primaryGroupHasEventMessageTrackFlags[i] ? trackGroupCount++ : C.INDEX_UNSET;
+      int cea608TrackGroupIndex =
+          primaryGroupHasCea608TrackFlags[i] ? trackGroupCount++ : C.INDEX_UNSET;
+
+      trackGroups[primaryTrackGroupIndex] = new TrackGroup(formats);
+      trackGroupInfos[primaryTrackGroupIndex] =
+          TrackGroupInfo.primaryTrack(
+              firstAdaptationSet.type,
+              adaptationSetIndices,
+              primaryTrackGroupIndex,
+              eventMessageTrackGroupIndex,
+              cea608TrackGroupIndex);
+      if (eventMessageTrackGroupIndex != C.INDEX_UNSET) {
         Format format = Format.createSampleFormat(firstAdaptationSet.id + ":emsg",
             MimeTypes.APPLICATION_EMSG, null, Format.NO_VALUE, null);
-        trackGroups[trackGroupCount] = new TrackGroup(format);
-        trackGroupInfos[trackGroupCount++] = TrackGroupInfo.embeddedEmsgTrack(adaptationSetIndices,
-            primaryTrackGroupIndex);
+        trackGroups[eventMessageTrackGroupIndex] = new TrackGroup(format);
+        trackGroupInfos[eventMessageTrackGroupIndex] =
+            TrackGroupInfo.embeddedEmsgTrack(adaptationSetIndices, primaryTrackGroupIndex);
       }
-      if (hasCea608Track) {
+      if (cea608TrackGroupIndex != C.INDEX_UNSET) {
         Format format = Format.createTextSampleFormat(firstAdaptationSet.id + ":cea608",
             MimeTypes.APPLICATION_CEA608, 0, null);
-        trackGroups[trackGroupCount] = new TrackGroup(format);
-        trackGroupInfos[trackGroupCount++] = TrackGroupInfo.embeddedCea608Track(
-            adaptationSetIndices, primaryTrackGroupIndex);
+        trackGroups[cea608TrackGroupIndex] = new TrackGroup(format);
+        trackGroupInfos[cea608TrackGroupIndex] =
+            TrackGroupInfo.embeddedCea608Track(adaptationSetIndices, primaryTrackGroupIndex);
       }
     }
     return trackGroupCount;
@@ -476,24 +483,39 @@ import java.util.Map;
       TrackSelection selection, long positionUs) {
     int embeddedTrackCount = 0;
     int[] embeddedTrackTypes = new int[2];
-    boolean enableEventMessageTrack = trackGroupInfo.hasEmbeddedEventMessageTrack;
+    Format[] embeddedTrackFormats = new Format[2];
+    boolean enableEventMessageTrack =
+        trackGroupInfo.embeddedEventMessageTrackGroupIndex != C.INDEX_UNSET;
     if (enableEventMessageTrack) {
+      embeddedTrackFormats[embeddedTrackCount] =
+          trackGroups.get(trackGroupInfo.embeddedEventMessageTrackGroupIndex).getFormat(0);
       embeddedTrackTypes[embeddedTrackCount++] = C.TRACK_TYPE_METADATA;
     }
-    boolean enableCea608Track = trackGroupInfo.hasEmbeddedCea608Track;
+    boolean enableCea608Track = trackGroupInfo.embeddedCea608TrackGroupIndex != C.INDEX_UNSET;
     if (enableCea608Track) {
+      embeddedTrackFormats[embeddedTrackCount] =
+          trackGroups.get(trackGroupInfo.embeddedCea608TrackGroupIndex).getFormat(0);
       embeddedTrackTypes[embeddedTrackCount++] = C.TRACK_TYPE_TEXT;
     }
     if (embeddedTrackCount < embeddedTrackTypes.length) {
+      embeddedTrackFormats = Arrays.copyOf(embeddedTrackFormats, embeddedTrackCount);
       embeddedTrackTypes = Arrays.copyOf(embeddedTrackTypes, embeddedTrackCount);
     }
     DashChunkSource chunkSource = chunkSourceFactory.createDashChunkSource(
         manifestLoaderErrorThrower, manifest, periodIndex, trackGroupInfo.adaptationSetIndices,
         selection, trackGroupInfo.trackType, elapsedRealtimeOffset, enableEventMessageTrack,
         enableCea608Track);
-    ChunkSampleStream<DashChunkSource> stream = new ChunkSampleStream<>(trackGroupInfo.trackType,
-        embeddedTrackTypes, chunkSource, this, allocator, positionUs, minLoadableRetryCount,
-        eventDispatcher);
+    ChunkSampleStream<DashChunkSource> stream =
+        new ChunkSampleStream<>(
+            trackGroupInfo.trackType,
+            embeddedTrackTypes,
+            embeddedTrackFormats,
+            chunkSource,
+            this,
+            allocator,
+            positionUs,
+            minLoadableRetryCount,
+            eventDispatcher);
     return stream;
   }
 
@@ -578,43 +600,74 @@ import java.util.Map;
 
     public final int eventStreamGroupIndex;
     public final int primaryTrackGroupIndex;
-    public final boolean hasEmbeddedEventMessageTrack;
-    public final boolean hasEmbeddedCea608Track;
-
-    public static TrackGroupInfo primaryTrack(int trackType, int[] adaptationSetIndices,
-        int primaryTrackGroupIndex, boolean hasEmbeddedEventMessageTrack,
-        boolean hasEmbeddedCea608Track) {
-      return new TrackGroupInfo(trackType, CATEGORY_PRIMARY, adaptationSetIndices,
-          primaryTrackGroupIndex, hasEmbeddedEventMessageTrack, hasEmbeddedCea608Track, -1);
+    public final int embeddedEventMessageTrackGroupIndex;
+    public final int embeddedCea608TrackGroupIndex;
+
+    public static TrackGroupInfo primaryTrack(
+        int trackType,
+        int[] adaptationSetIndices,
+        int primaryTrackGroupIndex,
+        int embeddedEventMessageTrackGroupIndex,
+        int embeddedCea608TrackGroupIndex) {
+      return new TrackGroupInfo(
+          trackType,
+          CATEGORY_PRIMARY,
+          adaptationSetIndices,
+          primaryTrackGroupIndex,
+          embeddedEventMessageTrackGroupIndex,
+          embeddedCea608TrackGroupIndex,
+          -1);
     }
 
     public static TrackGroupInfo embeddedEmsgTrack(int[] adaptationSetIndices,
         int primaryTrackGroupIndex) {
-      return new TrackGroupInfo(C.TRACK_TYPE_METADATA, CATEGORY_EMBEDDED,
-          adaptationSetIndices, primaryTrackGroupIndex, false, false, -1);
+      return new TrackGroupInfo(
+          C.TRACK_TYPE_METADATA,
+          CATEGORY_EMBEDDED,
+          adaptationSetIndices,
+          primaryTrackGroupIndex,
+          C.INDEX_UNSET,
+          C.INDEX_UNSET,
+          -1);
     }
 
     public static TrackGroupInfo embeddedCea608Track(int[] adaptationSetIndices,
         int primaryTrackGroupIndex) {
-      return new TrackGroupInfo(C.TRACK_TYPE_TEXT, CATEGORY_EMBEDDED,
-          adaptationSetIndices, primaryTrackGroupIndex, false, false, -1);
+      return new TrackGroupInfo(
+          C.TRACK_TYPE_TEXT,
+          CATEGORY_EMBEDDED,
+          adaptationSetIndices,
+          primaryTrackGroupIndex,
+          C.INDEX_UNSET,
+          C.INDEX_UNSET,
+          -1);
     }
 
     public static TrackGroupInfo mpdEventTrack(int eventStreamIndex) {
-      return new TrackGroupInfo(C.TRACK_TYPE_METADATA, CATEGORY_MANIFEST_EVENTS,
-          null, -1, false, false, eventStreamIndex);
+      return new TrackGroupInfo(
+          C.TRACK_TYPE_METADATA,
+          CATEGORY_MANIFEST_EVENTS,
+          null,
+          -1,
+          C.INDEX_UNSET,
+          C.INDEX_UNSET,
+          eventStreamIndex);
     }
 
-    private TrackGroupInfo(int trackType, @TrackGroupCategory int trackGroupCategory,
-        int[] adaptationSetIndices, int primaryTrackGroupIndex,
-        boolean hasEmbeddedEventMessageTrack, boolean hasEmbeddedCea608Track,
+    private TrackGroupInfo(
+        int trackType,
+        @TrackGroupCategory int trackGroupCategory,
+        int[] adaptationSetIndices,
+        int primaryTrackGroupIndex,
+        int embeddedEventMessageTrackGroupIndex,
+        int embeddedCea608TrackGroupIndex,
         int eventStreamGroupIndex) {
       this.trackType = trackType;
       this.adaptationSetIndices = adaptationSetIndices;
       this.trackGroupCategory = trackGroupCategory;
       this.primaryTrackGroupIndex = primaryTrackGroupIndex;
-      this.hasEmbeddedEventMessageTrack = hasEmbeddedEventMessageTrack;
-      this.hasEmbeddedCea608Track = hasEmbeddedCea608Track;
+      this.embeddedEventMessageTrackGroupIndex = embeddedEventMessageTrackGroupIndex;
+      this.embeddedCea608TrackGroupIndex = embeddedCea608TrackGroupIndex;
       this.eventStreamGroupIndex = eventStreamGroupIndex;
     }
   }

library/smoothstreaming/src/main/java/com/google/android/exoplayer2/source/smoothstreaming/SsMediaPeriod.java

@@ -207,8 +207,16 @@ import java.util.ArrayList;
     int streamElementIndex = trackGroups.indexOf(selection.getTrackGroup());
     SsChunkSource chunkSource = chunkSourceFactory.createChunkSource(manifestLoaderErrorThrower,
         manifest, streamElementIndex, selection, trackEncryptionBoxes);
-    return new ChunkSampleStream<>(manifest.streamElements[streamElementIndex].type, null,
-        chunkSource, this, allocator, positionUs, minLoadableRetryCount, eventDispatcher);
+    return new ChunkSampleStream<>(
+        manifest.streamElements[streamElementIndex].type,
+        null,
+        null,
+        chunkSource,
+        this,
+        allocator,
+        positionUs,
+        minLoadableRetryCount,
+        eventDispatcher);
   }
 
   private static TrackGroupArray buildTrackGroups(SsManifest manifest) {

testutils/src/main/java/com/google/android/exoplayer2/testutil/FakeAdaptiveMediaPeriod.java

@@ -132,8 +132,15 @@ public class FakeAdaptiveMediaPeriod extends FakeMediaPeriod
   protected SampleStream createSampleStream(TrackSelection trackSelection) {
     FakeChunkSource chunkSource = chunkSourceFactory.createChunkSource(trackSelection, durationUs);
     return new ChunkSampleStream<>(
-        MimeTypes.getTrackType(trackSelection.getSelectedFormat().sampleMimeType), null,
-        chunkSource, this, allocator, 0, 3, eventDispatcher);
+        MimeTypes.getTrackType(trackSelection.getSelectedFormat().sampleMimeType),
+        null,
+        null,
+        chunkSource,
+        this,
+        allocator,
+        0,
+        3,
+        eventDispatcher);
   }
 
   @Override