Replace FrameProcessorChain#isEnded with listener method.

PiperOrigin-RevId: 455114693

libraries/transformer/src/androidTest/java/androidx/media3/transformer/FrameProcessorChainPixelTest.java

@@ -89,9 +89,10 @@ public final class FrameProcessorChainPixelTest {
   private final AtomicReference<FrameProcessingException> frameProcessingException =
       new AtomicReference<>();
 
+  private @MonotonicNonNull MediaFormat mediaFormat;
   private @MonotonicNonNull FrameProcessorChain frameProcessorChain;
   private volatile @MonotonicNonNull ImageReader outputImageReader;
-  private @MonotonicNonNull MediaFormat mediaFormat;
+  private volatile boolean frameProcessingEnded;
 
   @After
   public void release() {
@@ -354,7 +355,17 @@ public final class FrameProcessorChainPixelTest {
           checkNotNull(
               FrameProcessorChain.create(
                   context,
-                  /* listener= */ this.frameProcessingException::set,
+                  new FrameProcessorChain.Listener() {
+                    @Override
+                    public void onFrameProcessingError(FrameProcessingException exception) {
+                      frameProcessingException.set(exception);
+                    }
+
+                    @Override
+                    public void onFrameProcessingEnded() {
+                      frameProcessingEnded = true;
+                    }
+                  },
                   pixelWidthHeightRatio,
                   inputWidth,
                   inputHeight,
@@ -421,7 +432,7 @@ public final class FrameProcessorChainPixelTest {
   private Bitmap processFirstFrameAndEnd() throws InterruptedException {
     checkNotNull(frameProcessorChain).signalEndOfInputStream();
     Thread.sleep(FRAME_PROCESSING_WAIT_MS);
-    assertThat(frameProcessorChain.isEnded()).isTrue();
+    assertThat(frameProcessingEnded).isTrue();
     assertThat(frameProcessingException.get()).isNull();
 
     Image frameProcessorChainOutputImage = checkNotNull(outputImageReader).acquireLatestImage();

libraries/transformer/src/main/java/androidx/media3/transformer/FrameProcessorChain.java

@@ -71,8 +71,16 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
    * <p>This listener is only called from the {@link FrameProcessorChain}'s background thread.
    */
   public interface Listener {
-    /** Called when an exception occurs during asynchronous frame processing. */
+    /**
+     * Called when an exception occurs during asynchronous frame processing.
+     *
+     * <p>If an error occurred, consuming and producing further frames will not work as expected and
+     * the {@link FrameProcessorChain} should be released.
+     */
     void onFrameProcessingError(FrameProcessingException exception);
+
+    /** Called after the frame processor has produced its final output frame. */
+    void onFrameProcessingEnded();
   }
 
   /**
@@ -454,22 +462,24 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
     return pendingFrameCount.get();
   }
 
-  /** Informs the {@code FrameProcessorChain} that no further input frames should be accepted. */
+  /**
+   * Informs the {@code FrameProcessorChain} that no further input frames should be accepted.
+   *
+   * @throws IllegalStateException If called more than once.
+   */
   public void signalEndOfInputStream() {
+    checkState(!inputStreamEnded);
     inputStreamEnded = true;
-  }
+    futures.add(singleThreadExecutorService.submit(this::signalEndOfOutputStream));
-
-  /** Returns whether all frames have been processed. */
-  public boolean isEnded() {
-    return inputStreamEnded && getPendingFrameCount() == 0;
   }
 
   /**
    * Releases all resources.
    *
-   * <p>If the frame processor chain is released before it has {@linkplain #isEnded() ended}, it
+   * <p>If the frame processor chain is released before it has {@linkplain
-   * will attempt to cancel processing any input frames that have already become available. Input
+   * Listener#onFrameProcessingEnded() ended}, it will attempt to cancel processing any input frames
-   * frames that become available after release are ignored.
+   * that have already become available. Input frames that become available after release are
+   * ignored.
    *
    * <p>This method blocks until all OpenGL resources are released or releasing times out.
    */
@@ -563,6 +573,16 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
     }
   }
 
+  /** Calls {@link Listener#onFrameProcessingEnded()} once no more frames are pending. */
+  @WorkerThread
+  private void signalEndOfOutputStream() {
+    if (getPendingFrameCount() == 0) {
+      listener.onFrameProcessingEnded();
+    } else {
+      futures.add(singleThreadExecutorService.submit(this::signalEndOfOutputStream));
+    }
+  }
+
   /**
    * Releases the {@link SingleFrameGlTextureProcessor SingleFrameGlTextureProcessors} and destroys
    * the OpenGL context.

libraries/transformer/src/main/java/androidx/media3/transformer/VideoTranscodingSamplePipeline.java

@@ -51,8 +51,6 @@ import org.checkerframework.dataflow.qual.Pure;
   private final EncoderWrapper encoderWrapper;
   private final DecoderInputBuffer encoderOutputBuffer;
 
-  private boolean signaledEndOfStreamToEncoder;
-
   public VideoTranscodingSamplePipeline(
       Context context,
       Format inputFormat,
@@ -110,10 +108,23 @@ import org.checkerframework.dataflow.qual.Pure;
       frameProcessorChain =
           FrameProcessorChain.create(
               context,
-              /* listener= */ exception ->
+              new FrameProcessorChain.Listener() {
+                @Override
+                public void onFrameProcessingError(FrameProcessingException exception) {
                   asyncErrorListener.onTransformationException(
                       TransformationException.createForFrameProcessorChain(
-                          exception, TransformationException.ERROR_CODE_GL_PROCESSING_FAILED)),
+                          exception, TransformationException.ERROR_CODE_GL_PROCESSING_FAILED));
+                }
+
+                @Override
+                public void onFrameProcessingEnded() {
+                  try {
+                    encoderWrapper.signalEndOfInputStream();
+                  } catch (TransformationException exception) {
+                    asyncErrorListener.onTransformationException(exception);
+                  }
+                }
+              },
               inputFormat.pixelWidthHeightRatio,
               /* inputWidth= */ decodedWidth,
               /* inputHeight= */ decodedHeight,
@@ -157,13 +168,6 @@ import org.checkerframework.dataflow.qual.Pure;
 
   @Override
   public boolean processData() throws TransformationException {
-    if (frameProcessorChain.isEnded()) {
-      if (!signaledEndOfStreamToEncoder) {
-        encoderWrapper.signalEndOfInputStream();
-        signaledEndOfStreamToEncoder = true;
-      }
-      return false;
-    }
     if (decoder.isEnded()) {
       return false;
     }