Use outputStreamEnded for MetadataRenderer#isEnded

Issue: #8710
PiperOrigin-RevId: 366051836

RELEASENOTES.md

@@ -77,6 +77,9 @@
         spec ([#8704](https://github.com/google/ExoPlayer/issues/8704)).
     *   Support TTML `textEmphasis` attributes, used for Japanese boutens.
     *   Support TTML `shear` attributes.
+*   Metadata:
+    *   Ensure that timed metadata near the end of a period is not dropped
+        ([#8710](https://github.com/google/ExoPlayer/issues/8710)).
 *   MediaSession extension: Remove dependency to core module and rely on common
     only. The `TimelineQueueEditor` uses a new `MediaDescriptionConverter` for
     this purpose and does not rely on the `ConcatenatingMediaSource` anymore.

library/core/src/main/java/com/google/android/exoplayer2/metadata/MetadataRenderer.java

@@ -58,6 +58,7 @@ public final class MetadataRenderer extends BaseRenderer implements Callback {
   private int pendingMetadataCount;
   @Nullable private MetadataDecoder decoder;
   private boolean inputStreamEnded;
+  private boolean outputStreamEnded;
   private long subsampleOffsetUs;
 
   /**
@@ -118,6 +119,7 @@ public final class MetadataRenderer extends BaseRenderer implements Callback {
   protected void onPositionReset(long positionUs, boolean joining) {
     flushPendingMetadata();
     inputStreamEnded = false;
+    outputStreamEnded = false;
   }
 
   @Override
@@ -158,6 +160,9 @@ public final class MetadataRenderer extends BaseRenderer implements Callback {
       pendingMetadataIndex = (pendingMetadataIndex + 1) % MAX_PENDING_METADATA_COUNT;
       pendingMetadataCount--;
     }
+    if (inputStreamEnded && pendingMetadataCount == 0) {
+      outputStreamEnded = true;
+    }
   }
 
   /**
@@ -198,7 +203,7 @@ public final class MetadataRenderer extends BaseRenderer implements Callback {
 
   @Override
   public boolean isEnded() {
-    return inputStreamEnded;
+    return outputStreamEnded;
   }
 
   @Override