Fix transcoding drops a few frames.

In the old version, the transcoder uses decoder.isEnded() alone as the criteria
to stop the encoding/muxing process. It's rectified to:

- On decoder ending, signal the encoder of EOS after writing all decoded frames to it.
- On encoder ending, write end track to muxer.

PiperOrigin-RevId: 393322114

library/core/src/main/java/com/google/android/exoplayer2/mediacodec/AsynchronousMediaCodecAdapter.java

@@ -303,6 +303,11 @@ import java.nio.ByteBuffer;
     codec.setVideoScalingMode(scalingMode);
   }
 
+  @Override
+  public void signalEndOfInputStream() {
+    codec.signalEndOfInputStream();
+  }
+
   @VisibleForTesting
   /* package */ void onError(MediaCodec.CodecException error) {
     asynchronousMediaCodecCallback.onError(codec, error);

library/core/src/main/java/com/google/android/exoplayer2/mediacodec/MediaCodecAdapter.java

@@ -242,4 +242,13 @@ public interface MediaCodecAdapter {
 
   /** Whether the adapter needs to be reconfigured before it is used. */
   boolean needsReconfiguration();
+
+  /**
+   * Signals the encoder of end-of-stream on input. The call can only be used when the encoder
+   * receives its input from a {@link Surface surface}.
+   *
+   * @see MediaCodec#signalEndOfInputStream()
+   */
+  @RequiresApi(18)
+  void signalEndOfInputStream();
 }

library/core/src/main/java/com/google/android/exoplayer2/mediacodec/SynchronousMediaCodecAdapter.java

@@ -200,6 +200,12 @@ public class SynchronousMediaCodecAdapter implements MediaCodecAdapter {
   }
 
   @Override
+  @RequiresApi(18)
+  public void signalEndOfInputStream() {
+    Api18.signalEndOfInputStream(codec);
+  }
+
+  @Override
   @RequiresApi(23)
   public void setOnFrameRenderedListener(OnFrameRenderedListener listener, Handler handler) {
     codec.setOnFrameRenderedListener(
@@ -232,5 +238,10 @@ public class SynchronousMediaCodecAdapter implements MediaCodecAdapter {
     public static Surface createCodecInputSurface(MediaCodec codec) {
       return codec.createInputSurface();
     }
+
+    @DoNotInline
+    public static void signalEndOfInputStream(MediaCodec codec) {
+      codec.signalEndOfInputStream();
+    }
   }
 }

library/transformer/src/main/java/com/google/android/exoplayer2/transformer/MediaCodecAdapterWrapper.java

@@ -311,6 +311,11 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
     inputBuffer.data = null;
   }
 
+  @RequiresApi(18)
+  public void signalEndOfInputStream() {
+    codec.signalEndOfInputStream();
+  }
+
   /** Returns the current output format, if available. */
   @Nullable
   public Format getOutputFormat() {

library/transformer/src/main/java/com/google/android/exoplayer2/transformer/TransformerTranscodingVideoRenderer.java

@@ -175,8 +175,15 @@ import java.nio.ByteBuffer;
     if (decoder.isEnded()) {
       return false;
     }
+
     // Rendering the decoder output queues input to the encoder because they share the same surface.
-    return decoder.maybeDequeueRenderAndReleaseOutputBuffer();
+    boolean hasProcessedOutputBuffer = decoder.maybeDequeueRenderAndReleaseOutputBuffer();
+    if (decoder.isEnded()) {
+      checkNotNull(encoder).signalEndOfInputStream();
+      // All decoded frames have been rendered to the encoder's input surface.
+      return false;
+    }
+    return hasProcessedOutputBuffer;
   }
 
   private boolean feedMuxerFromEncoder() {
@@ -190,10 +197,7 @@ import java.nio.ByteBuffer;
       muxerWrapper.addTrackFormat(encoderOutputFormat);
     }
 
-    // TODO(claincly) May have to use inputStreamBuffer.isEndOfStream result to call
-    // decoder.signalEndOfInputStream().
-    MediaCodecAdapterWrapper decoder = checkNotNull(this.decoder);
-    if (decoder.isEnded()) {
+    if (encoder.isEnded()) {
       muxerWrapper.endTrack(getTrackType());
       muxerWrapperTrackEnded = true;
       return false;

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

@@ -268,6 +268,12 @@ public class CapturingRenderersFactory implements RenderersFactory, Dumper.Dumpa
       delegate.setVideoScalingMode(scalingMode);
     }
 
+    @RequiresApi(18)
+    @Override
+    public void signalEndOfInputStream() {
+      delegate.signalEndOfInputStream();
+    }
+
     // Dumpable implementation
 
     @Override