Ensure silence skipping doesn't interfere with other discontinuities

The same doSomeWork iteration that triggers the silence skipping
discontinuity may already have another discontinuities (like
AUTO_TRANSITION), which should take precedence over the silence
skipping.

PiperOrigin-RevId: 632432851

RELEASENOTES.md

@@ -24,6 +24,8 @@
         `DefaultPreloadManager` and the custom
         `PreloadMediaSource.PreloadControl` implementations to preload the next
         source or take other actions.
+    *   Fix bug where silence skipping at the end of items can trigger a
+        playback exception.
 *   Transformer:
     *   Work around a decoder bug where the number of audio channels was capped
         at stereo when handling PCM input.

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/ExoPlayerImplInternal.java

@@ -1038,13 +1038,15 @@ import java.util.concurrent.atomic.AtomicBoolean;
       long periodPositionUs = playingPeriodHolder.toPeriodTime(rendererPositionUs);
       maybeTriggerPendingMessages(playbackInfo.positionUs, periodPositionUs);
       if (mediaClock.hasSkippedSilenceSinceLastCall()) {
+        // Only report silence skipping if there isn't already another discontinuity.
+        boolean reportSilenceSkip = !playbackInfoUpdate.positionDiscontinuity;
         playbackInfo =
             handlePositionDiscontinuity(
                 playbackInfo.periodId,
                 /* positionUs= */ periodPositionUs,
                 playbackInfo.requestedContentPositionUs,
                 /* discontinuityStartPositionUs= */ periodPositionUs,
-                /* reportDiscontinuity= */ true,
+                /* reportDiscontinuity= */ reportSilenceSkip,
                 Player.DISCONTINUITY_REASON_SILENCE_SKIP);
       } else {
         playbackInfo.updatePositionUs(periodPositionUs);

libraries/exoplayer/src/test/java/androidx/media3/exoplayer/ExoPlayerTest.java

@@ -14748,6 +14748,62 @@ public class ExoPlayerTest {
     player.release();
   }
 
+  @Test
+  public void silenceSkipped_atItemTransition_doesNotHideAutoTransitionDiscontinuity()
+      throws Exception {
+    FakeMediaClockRenderer audioRenderer =
+        new FakeMediaClockRenderer(C.TRACK_TYPE_AUDIO) {
+          private long positionUs;
+
+          @Override
+          protected void onStreamChanged(
+              Format[] formats, long startPositionUs, long offsetUs, MediaPeriodId mediaPeriodId) {
+            positionUs = offsetUs;
+          }
+
+          @Override
+          public long getPositionUs() {
+            // Advance position to make playback progress.
+            positionUs += 10_000;
+            return positionUs;
+          }
+
+          @Override
+          public boolean hasSkippedSilenceSinceLastCall() {
+            // Contuniuosly report skipped silences to ensure they will overlap with other
+            // discontinuities like AUTO_TRANSITION.
+            return true;
+          }
+
+          @Override
+          public void setPlaybackParameters(PlaybackParameters playbackParameters) {}
+
+          @Override
+          public PlaybackParameters getPlaybackParameters() {
+            return PlaybackParameters.DEFAULT;
+          }
+        };
+    ExoPlayer player =
+        parameterizeTestExoPlayerBuilder(
+                new TestExoPlayerBuilder(context).setRenderers(audioRenderer))
+            .build();
+    Player.Listener mockPlayerListener = mock(Player.Listener.class);
+    player.addListener(mockPlayerListener);
+
+    player.setMediaSources(
+        ImmutableList.of(
+            new FakeMediaSource(new FakeTimeline(), ExoPlayerTestRunner.AUDIO_FORMAT),
+            new FakeMediaSource(new FakeTimeline(), ExoPlayerTestRunner.AUDIO_FORMAT),
+            new FakeMediaSource(new FakeTimeline(), ExoPlayerTestRunner.AUDIO_FORMAT)));
+    player.prepare();
+    player.play();
+    runUntilPlaybackState(player, Player.STATE_ENDED);
+    player.release();
+
+    verify(mockPlayerListener, times(2))
+        .onPositionDiscontinuity(any(), any(), eq(Player.DISCONTINUITY_REASON_AUTO_TRANSITION));
+  }
+
   @Test
   public void seekToZeroAndTrackSelection_withNonZeroDefaultPosition_startsPlaybackAtZero()
       throws Exception {