DASH: Fix detection of end of live events

The remaining work is to split Window.isDynamic so that it's
possible to represent a window that wont be appended to, but
may still be removed from.

Issue: #4780

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=221439220

RELEASENOTES.md

@@ -2,6 +2,8 @@
 
 ### 2.9.2 ###
 
+* DASH: Fix detecting the end of live events
+  ([#4780](https://github.com/google/ExoPlayer/issues/4780)).
 * Include channel count in audio capabilities check
   ([#4690](https://github.com/google/ExoPlayer/issues/4690)).
 

library/core/src/main/java/com/google/android/exoplayer2/Timeline.java

@@ -139,9 +139,12 @@ public abstract class Timeline {
      */
     public boolean isSeekable;
 
-    /**
-     * Whether this window may change when the timeline is updated.
-     */
+    // TODO: Split this to better describe which parts of the window might change. For example it
+    // should be possible to individually determine whether the start and end positions of the
+    // window may change relative to the underlying periods. For an example of where it's useful to
+    // know that the end position is fixed whilst the start position may still change, see:
+    // https://github.com/google/ExoPlayer/issues/4780.
+    /** Whether this window may change when the timeline is updated. */
     public boolean isDynamic;
 
     /**

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

@@ -376,7 +376,6 @@ public final class DashMediaSource extends BaseMediaSource {
 
   private int staleManifestReloadAttempt;
   private long expiredManifestPublishTimeUs;
-  private boolean dynamicMediaPresentationEnded;
 
   private int firstPeriodId;
 
@@ -679,7 +678,6 @@ public final class DashMediaSource extends BaseMediaSource {
     elapsedRealtimeOffsetMs = 0;
     staleManifestReloadAttempt = 0;
     expiredManifestPublishTimeUs = C.TIME_UNSET;
-    dynamicMediaPresentationEnded = false;
     firstPeriodId = 0;
     periodsById.clear();
   }
@@ -691,10 +689,6 @@ public final class DashMediaSource extends BaseMediaSource {
     startLoadingManifest();
   }
 
-  /* package */ void onDashLiveMediaPresentationEndSignalEncountered() {
-    this.dynamicMediaPresentationEnded = true;
-  }
-
   /* package */ void onDashManifestPublishTimeExpired(long expiredManifestPublishTimeUs) {
     if (this.expiredManifestPublishTimeUs == C.TIME_UNSET
         || this.expiredManifestPublishTimeUs < expiredManifestPublishTimeUs) {
@@ -734,9 +728,8 @@ public final class DashMediaSource extends BaseMediaSource {
         // behind.
         Log.w(TAG, "Loaded out of sync manifest");
         isManifestStale = true;
-      } else if (dynamicMediaPresentationEnded
-          || (expiredManifestPublishTimeUs != C.TIME_UNSET
-              && newManifest.publishTimeMs * 1000 <= expiredManifestPublishTimeUs)) {
+      } else if (expiredManifestPublishTimeUs != C.TIME_UNSET
+          && newManifest.publishTimeMs * 1000 <= expiredManifestPublishTimeUs) {
         // If we receive a dynamic manifest that's older than expected (i.e. its publish time has
         // expired, or it's dynamic and we know the presentation has ended), then this manifest is
         // stale.
@@ -745,8 +738,6 @@ public final class DashMediaSource extends BaseMediaSource {
             "Loaded stale dynamic manifest: "
                 + newManifest.publishTimeMs
                 + ", "
-                + dynamicMediaPresentationEnded
-                + ", "
                 + expiredManifestPublishTimeUs);
         isManifestStale = true;
       }
@@ -763,7 +754,6 @@ public final class DashMediaSource extends BaseMediaSource {
       staleManifestReloadAttempt = 0;
     }
 
-
     manifest = newManifest;
     manifestLoadPending &= manifest.dynamic;
     manifestLoadStartTimestampMs = elapsedRealtimeMs - loadDurationMs;
@@ -1170,12 +1160,16 @@ public final class DashMediaSource extends BaseMediaSource {
       long windowDefaultStartPositionUs = getAdjustedWindowDefaultStartPositionUs(
           defaultPositionProjectionUs);
       Object tag = setTag ? windowTag : null;
+      boolean isDynamic =
+          manifest.dynamic
+              && manifest.minUpdatePeriodMs != C.TIME_UNSET
+              && manifest.durationMs == C.TIME_UNSET;
       return window.set(
           tag,
           presentationStartTimeMs,
           windowStartTimeMs,
           /* isSeekable= */ true,
-          manifest.dynamic,
+          isDynamic,
           windowDefaultStartPositionUs,
           windowDurationUs,
           /* firstPeriodIndex= */ 0,
@@ -1253,11 +1247,6 @@ public final class DashMediaSource extends BaseMediaSource {
     public void onDashManifestPublishTimeExpired(long expiredManifestPublishTimeUs) {
       DashMediaSource.this.onDashManifestPublishTimeExpired(expiredManifestPublishTimeUs);
     }
-
-    @Override
-    public void onDashLiveMediaPresentationEndSignalEncountered() {
-      DashMediaSource.this.onDashLiveMediaPresentationEndSignalEncountered();
-    }
   }
 
   private final class ManifestCallback implements Loader.Callback<ParsingLoadable<DashManifest>> {

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

@@ -318,9 +318,12 @@ public class DefaultDashChunkSource implements DashChunkSource {
       }
     }
 
+    long periodDurationUs = representationHolder.periodDurationUs;
+    boolean periodEnded = periodDurationUs != C.TIME_UNSET;
+
     if (representationHolder.getSegmentCount() == 0) {
       // The index doesn't define any segments.
-      out.endOfStream = !manifest.dynamic || (periodIndex < manifest.getPeriodCount() - 1);
+      out.endOfStream = periodEnded;
       return;
     }
 
@@ -343,17 +346,15 @@ public class DefaultDashChunkSource implements DashChunkSource {
       fatalError = new BehindLiveWindowException();
       return;
     }
+
     if (segmentNum > lastAvailableSegmentNum
         || (missingLastSegment && segmentNum >= lastAvailableSegmentNum)) {
-      // The segment is beyond the end of the period. We know the period will not be extended if the
-      // manifest is static, or if there's a period after this one.
-      out.endOfStream = !manifest.dynamic || (periodIndex < manifest.getPeriodCount() - 1);
+      // The segment is beyond the end of the period.
+      out.endOfStream = periodEnded;
       return;
     }
 
-    long periodDurationUs = representationHolder.periodDurationUs;
-    if (periodDurationUs != C.TIME_UNSET
-        && representationHolder.getSegmentStartTimeUs(segmentNum) >= periodDurationUs) {
+    if (periodEnded && representationHolder.getSegmentStartTimeUs(segmentNum) >= periodDurationUs) {
       // The period duration clips the period to a position before the segment.
       out.endOfStream = true;
       return;

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

@@ -60,8 +60,7 @@ import java.util.TreeMap;
  */
 public final class PlayerEmsgHandler implements Handler.Callback {
 
-  private static final int EMSG_MEDIA_PRESENTATION_ENDED = 1;
-  private static final int EMSG_MANIFEST_EXPIRED = 2;
+  private static final int EMSG_MANIFEST_EXPIRED = 1;
 
   /** Callbacks for player emsg events encountered during DASH live stream. */
   public interface PlayerEmsgCallback {
@@ -75,9 +74,6 @@ public final class PlayerEmsgHandler implements Handler.Callback {
      * @param expiredManifestPublishTimeUs The manifest publish time that has been expired.
      */
     void onDashManifestPublishTimeExpired(long expiredManifestPublishTimeUs);
-
-    /** Called when a media presentation end signal is encountered during live stream. * */
-    void onDashLiveMediaPresentationEndSignalEncountered();
   }
 
   private final Allocator allocator;
@@ -88,7 +84,6 @@ public final class PlayerEmsgHandler implements Handler.Callback {
 
   private DashManifest manifest;
 
-  private boolean dynamicMediaPresentationEnded;
   private long expiredManifestPublishTimeUs;
   private long lastLoadedChunkEndTimeUs;
   private long lastLoadedChunkEndTimeBeforeRefreshUs;
@@ -134,21 +129,15 @@ public final class PlayerEmsgHandler implements Handler.Callback {
       return true;
     }
     boolean manifestRefreshNeeded = false;
-    if (dynamicMediaPresentationEnded) {
-      // The manifest we have is dynamic, but we know a non-dynamic one representing the final state
-      // should be available.
-      manifestRefreshNeeded = true;
-    } else {
-      // Find the smallest publishTime (greater than or equal to the current manifest's publish
-      // time) that has a corresponding expiry time.
-      Map.Entry<Long, Long> expiredEntry = ceilingExpiryEntryForPublishTime(manifest.publishTimeMs);
-      if (expiredEntry != null) {
-        long expiredPointUs = expiredEntry.getValue();
-        if (expiredPointUs < presentationPositionUs) {
-          expiredManifestPublishTimeUs = expiredEntry.getKey();
-          notifyManifestPublishTimeExpired();
-          manifestRefreshNeeded = true;
-        }
+    // Find the smallest publishTime (greater than or equal to the current manifest's publish time)
+    // that has a corresponding expiry time.
+    Map.Entry<Long, Long> expiredEntry = ceilingExpiryEntryForPublishTime(manifest.publishTimeMs);
+    if (expiredEntry != null) {
+      long expiredPointUs = expiredEntry.getValue();
+      if (expiredPointUs < presentationPositionUs) {
+        expiredManifestPublishTimeUs = expiredEntry.getKey();
+        notifyManifestPublishTimeExpired();
+        manifestRefreshNeeded = true;
       }
     }
     if (manifestRefreshNeeded) {
@@ -221,9 +210,6 @@ public final class PlayerEmsgHandler implements Handler.Callback {
       return true;
     }
     switch (message.what) {
-      case (EMSG_MEDIA_PRESENTATION_ENDED):
-        handleMediaPresentationEndedMessageEncountered();
-        return true;
       case (EMSG_MANIFEST_EXPIRED):
         ManifestExpiryEventInfo messageObj = (ManifestExpiryEventInfo) message.obj;
         handleManifestExpiredMessage(
@@ -248,11 +234,6 @@ public final class PlayerEmsgHandler implements Handler.Callback {
     }
   }
 
-  private void handleMediaPresentationEndedMessageEncountered() {
-    dynamicMediaPresentationEnded = true;
-    notifySourceMediaPresentationEnded();
-  }
-
   private @Nullable Map.Entry<Long, Long> ceilingExpiryEntryForPublishTime(long publishTimeMs) {
     return manifestPublishTimeToExpiryTimeUs.ceilingEntry(publishTimeMs);
   }
@@ -273,10 +254,6 @@ public final class PlayerEmsgHandler implements Handler.Callback {
     playerEmsgCallback.onDashManifestPublishTimeExpired(expiredManifestPublishTimeUs);
   }
 
-  private void notifySourceMediaPresentationEnded() {
-    playerEmsgCallback.onDashLiveMediaPresentationEndSignalEncountered();
-  }
-
   /** Requests DASH media manifest to be refreshed if necessary. */
   private void maybeNotifyDashManifestRefreshNeeded() {
     if (lastLoadedChunkEndTimeBeforeRefreshUs != C.TIME_UNSET
@@ -298,12 +275,6 @@ public final class PlayerEmsgHandler implements Handler.Callback {
     }
   }
 
-  private static boolean isMessageSignalingMediaPresentationEnded(EventMessage eventMessage) {
-    // According to section 4.5.2.1 DASH-IF IOP, if both presentation time delta and event duration
-    // are zero, the media presentation is ended.
-    return eventMessage.presentationTimeUs == 0 && eventMessage.durationMs == 0;
-  }
-
   /** Handles emsg messages for a specific track for the player. */
   public final class PlayerTrackEmsgHandler implements TrackOutput {
 
@@ -413,16 +384,7 @@ public final class PlayerEmsgHandler implements Handler.Callback {
       if (manifestPublishTimeMsInEmsg == C.TIME_UNSET) {
         return;
       }
-
-      if (isMessageSignalingMediaPresentationEnded(eventMessage)) {
-        onMediaPresentationEndedMessageEncountered();
-      } else {
-        onManifestExpiredMessageEncountered(eventTimeUs, manifestPublishTimeMsInEmsg);
-      }
-    }
-
-    private void onMediaPresentationEndedMessageEncountered() {
-      handler.sendMessage(handler.obtainMessage(EMSG_MEDIA_PRESENTATION_ENDED));
+      onManifestExpiredMessageEncountered(eventTimeUs, manifestPublishTimeMsInEmsg);
     }
 
     private void onManifestExpiredMessageEncountered(