Allow playback regardless buffered duration when loading fails

It is possible for playback to be stuck when there is failure in loading further data, while the player is required to load more due to the buffered duration being under `DefaultLoadControl.bufferForPlayback`. Therefore, we check if there is any loading error in `isLoadingPossible`, so that the player will allow the playback of the existing data rather than waiting forever for the data that can never be loaded.

Issue: #1571
PiperOrigin-RevId: 665801674
(cherry picked from commit 351593a)

RELEASENOTES.md

@@ -6,6 +6,8 @@
 *   ExoPlayer:
     *   Handle preload callbacks asynchronously in `PreloadMediaSource`
         ([#1568](https://github.com/androidx/media/issues/1568)).
+    *   Allow playback regardless of buffered duration when loading fails
+        ([#1571](https://github.com/androidx/media/issues/1571)).
 *   Transformer:
 *   Track Selection:
 *   Extractors:

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

@@ -2633,6 +2633,9 @@ private boolean isLoadingPossible() {
     if (loadingPeriodHolder == null) {
       return false;
     }
+    if (loadingPeriodHolder.hasLoadingError()) {
+      return false;
+    }
     long nextLoadPositionUs = loadingPeriodHolder.getNextLoadPositionUs();
     if (nextLoadPositionUs == C.TIME_END_OF_SOURCE) {
       return false;

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

@@ -35,6 +35,7 @@
 import androidx.media3.exoplayer.trackselection.TrackSelector;
 import androidx.media3.exoplayer.trackselection.TrackSelectorResult;
 import androidx.media3.exoplayer.upstream.Allocator;
+import java.io.IOException;
 
 /** Holds a {@link MediaPeriod} with information required to play it as part of a timeline. */
 /* package */ final class MediaPeriodHolder {
@@ -394,6 +395,27 @@ public void updateClipping() {
     }
   }
 
+  /**
+   * Returns whether the media period has encountered an error that prevents it from being prepared
+   * or reading data.
+   */
+  public boolean hasLoadingError() {
+    try {
+      if (!prepared) {
+        mediaPeriod.maybeThrowPrepareError();
+      } else {
+        for (SampleStream sampleStream : sampleStreams) {
+          if (sampleStream != null) {
+            sampleStream.maybeThrowError();
+          }
+        }
+      }
+    } catch (IOException e) {
+      return true;
+    }
+    return false;
+  }
+
   private void enableTrackSelectionsInResult() {
     if (!isLoadingMediaPeriod()) {
       return;

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

@@ -10794,6 +10794,62 @@ public void maybeThrowPrepareError() throws IOException {
     player.release();
   }
 
+  @Test
+  public void
+      mediaPeriodMaybeThrowPrepareError_bufferedDurationUnderMinimumBufferForPlayback_keepPlayingUntilBufferedDataExhausts()
+          throws Exception {
+    ExoPlayer player = parameterizeTestExoPlayerBuilder(new TestExoPlayerBuilder(context)).build();
+    // Define a timeline that has a short duration of 1 second for the first item, which is smaller
+    // than the default buffer duration for playback in DefaultLoadControl (2.5 seconds).
+    Timeline timeline =
+        new FakeTimeline(
+            new TimelineWindowDefinition(
+                /* isSeekable= */ true,
+                /* isDynamic= */ false,
+                /* durationUs= */ 1 * C.MICROS_PER_SECOND));
+    player.addMediaSource(new FakeMediaSource(timeline, ExoPlayerTestRunner.VIDEO_FORMAT));
+    player.addMediaSource(
+        new FakeMediaSource(timeline, ExoPlayerTestRunner.VIDEO_FORMAT) {
+          @Override
+          protected MediaPeriod createMediaPeriod(
+              MediaPeriodId id,
+              TrackGroupArray trackGroupArray,
+              Allocator allocator,
+              MediaSourceEventListener.EventDispatcher mediaSourceEventDispatcher,
+              DrmSessionManager drmSessionManager,
+              DrmSessionEventListener.EventDispatcher drmEventDispatcher,
+              @Nullable TransferListener transferListener) {
+            return new FakeMediaPeriod(
+                trackGroupArray,
+                allocator,
+                /* singleSampleTimeUs= */ 0,
+                mediaSourceEventDispatcher,
+                DrmSessionManager.DRM_UNSUPPORTED,
+                drmEventDispatcher,
+                /* deferOnPrepared= */ true) {
+              @Override
+              public void maybeThrowPrepareError() throws IOException {
+                throw new IOException();
+              }
+            };
+          }
+        });
+
+    player.prepare();
+    player.play();
+    ExoPlaybackException error = TestPlayerRunHelper.runUntilError(player);
+
+    Object period1Uid =
+        player
+            .getCurrentTimeline()
+            .getPeriod(/* periodIndex= */ 1, new Timeline.Period(), /* setIds= */ true)
+            .uid;
+    assertThat(error.mediaPeriodId.periodUid).isEqualTo(period1Uid);
+    assertThat(player.getCurrentMediaItemIndex()).isEqualTo(1);
+
+    player.release();
+  }
+
   @Test
   public void sampleStreamMaybeThrowError_isNotThrownUntilPlaybackReachedFailingItem()
       throws Exception {
@@ -10859,6 +10915,79 @@ public void maybeThrowError() throws IOException {
     player.release();
   }
 
+  @Test
+  public void
+      sampleStreamMaybeThrowError_bufferedDurationUnderMinimumBufferForPlayback_keepPlayingUntilBufferedDataExhausts()
+          throws Exception {
+    ExoPlayer player = parameterizeTestExoPlayerBuilder(new TestExoPlayerBuilder(context)).build();
+    // Define a timeline that has a short duration of 1 second for the first item, which is smaller
+    // than the default buffer duration for playback in DefaultLoadControl (2.5 seconds).
+    Timeline timeline =
+        new FakeTimeline(
+            new TimelineWindowDefinition(
+                /* isSeekable= */ true,
+                /* isDynamic= */ false,
+                /* durationUs= */ 1 * C.MICROS_PER_SECOND));
+    player.addMediaSource(new FakeMediaSource(timeline, ExoPlayerTestRunner.VIDEO_FORMAT));
+    player.addMediaSource(
+        new FakeMediaSource(timeline, ExoPlayerTestRunner.VIDEO_FORMAT) {
+          @Override
+          protected MediaPeriod createMediaPeriod(
+              MediaPeriodId id,
+              TrackGroupArray trackGroupArray,
+              Allocator allocator,
+              MediaSourceEventListener.EventDispatcher mediaSourceEventDispatcher,
+              DrmSessionManager drmSessionManager,
+              DrmSessionEventListener.EventDispatcher drmEventDispatcher,
+              @Nullable TransferListener transferListener) {
+            return new FakeMediaPeriod(
+                trackGroupArray,
+                allocator,
+                /* trackDataFactory= */ (format, mediaPeriodId) -> ImmutableList.of(),
+                mediaSourceEventDispatcher,
+                drmSessionManager,
+                drmEventDispatcher,
+                /* deferOnPrepared= */ false) {
+              @Override
+              protected FakeSampleStream createSampleStream(
+                  Allocator allocator,
+                  @Nullable MediaSourceEventListener.EventDispatcher mediaSourceEventDispatcher,
+                  DrmSessionManager drmSessionManager,
+                  DrmSessionEventListener.EventDispatcher drmEventDispatcher,
+                  Format initialFormat,
+                  List<FakeSampleStreamItem> fakeSampleStreamItems) {
+                return new FakeSampleStream(
+                    allocator,
+                    mediaSourceEventDispatcher,
+                    drmSessionManager,
+                    drmEventDispatcher,
+                    initialFormat,
+                    fakeSampleStreamItems) {
+                  @Override
+                  public void maybeThrowError() throws IOException {
+                    throw new IOException();
+                  }
+                };
+              }
+            };
+          }
+        });
+
+    player.prepare();
+    player.play();
+    ExoPlaybackException error = TestPlayerRunHelper.runUntilError(player);
+
+    Object period1Uid =
+        player
+            .getCurrentTimeline()
+            .getPeriod(/* periodIndex= */ 1, new Timeline.Period(), /* setIds= */ true)
+            .uid;
+    assertThat(error.mediaPeriodId.periodUid).isEqualTo(period1Uid);
+    assertThat(player.getCurrentMediaItemIndex()).isEqualTo(1);
+
+    player.release();
+  }
+
   @Test
   public void rendererError_isReportedWithReadingMediaPeriodId() throws Exception {
     FakeMediaSource source0 =