Compositor: Add support for multiple bitmaps, and add testrunner

* Allow more than one input bitmap at a time.
* Allow Compositor to take in and set up an Executor. Otherwise,
Compositor resources may be created on one thread and accessed on another.
* Add a Compositor TestRunner to reuse test code more.
* Update VideoFrameProcessingTaskExecutor to use a new onError listener, so
that it's more reusable in non-DVFP contexts, like for Compositor.

PiperOrigin-RevId: 547206053

libraries/common/src/main/java/androidx/media3/common/VideoFrameProcessor.java

@@ -132,8 +132,7 @@ public interface VideoFrameProcessor {
     /**
      * Called when an exception occurs during asynchronous video frame processing.
      *
-     * <p>If an error occurred, consuming and producing further frames will not work as expected and
+     * <p>Using {@code VideoFrameProcessor} after an error happens is undefined behavior.
-     * the {@link VideoFrameProcessor} should be released.
      */
     void onError(VideoFrameProcessingException exception);
 

libraries/common/src/main/java/androidx/media3/common/util/GlUtil.java

@@ -690,6 +690,9 @@ public final class GlUtil {
   /**
    * Destroys the {@link EGLContext} identified by the provided {@link EGLDisplay} and {@link
    * EGLContext}.
+   *
+   * <p>This is a no-op if called on already-destroyed {@link EGLDisplay} and {@link EGLContext}
+   * instances.
    */
   @RequiresApi(17)
   public static void destroyEglContext(

libraries/effect/src/main/java/androidx/media3/effect/DefaultVideoFrameProcessor.java

@@ -99,7 +99,7 @@ public final class DefaultVideoFrameProcessor implements VideoFrameProcessor {
 
   /** A factory for {@link DefaultVideoFrameProcessor} instances. */
   public static final class Factory implements VideoFrameProcessor.Factory {
-    private static final String THREAD_NAME = "Effect:GlThread";
+    private static final String THREAD_NAME = "Effect:DefaultVideoFrameProcessor:GlThread";
 
     /** A builder for {@link DefaultVideoFrameProcessor.Factory} instances. */
     public static final class Builder {
@@ -285,7 +285,7 @@ public final class DefaultVideoFrameProcessor implements VideoFrameProcessor {
           executorService == null ? Util.newSingleThreadExecutor(THREAD_NAME) : executorService;
       VideoFrameProcessingTaskExecutor videoFrameProcessingTaskExecutor =
           new VideoFrameProcessingTaskExecutor(
-              instanceExecutorService, shouldShutdownExecutorService, listener);
+              instanceExecutorService, shouldShutdownExecutorService, listener::onError);
 
       Future<DefaultVideoFrameProcessor> defaultVideoFrameProcessorFuture =
           instanceExecutorService.submit(
@@ -554,9 +554,9 @@ public final class DefaultVideoFrameProcessor implements VideoFrameProcessor {
   public void release() {
     try {
       videoFrameProcessingTaskExecutor.release(/* releaseTask= */ this::releaseGlObjects);
-    } catch (InterruptedException unexpected) {
+    } catch (InterruptedException e) {
       Thread.currentThread().interrupt();
-      throw new IllegalStateException(unexpected);
+      throw new IllegalStateException(e);
     }
   }
 

libraries/effect/src/main/java/androidx/media3/effect/VideoCompositor.java

@@ -19,35 +19,52 @@ import static androidx.media3.common.util.Assertions.checkNotNull;
 import static androidx.media3.common.util.Assertions.checkState;
 
 import android.content.Context;
+import android.opengl.EGLContext;
+import android.opengl.EGLDisplay;
 import android.opengl.GLES20;
+import androidx.annotation.GuardedBy;
 import androidx.annotation.IntRange;
+import androidx.annotation.Nullable;
 import androidx.media3.common.GlObjectsProvider;
 import androidx.media3.common.GlTextureInfo;
 import androidx.media3.common.VideoFrameProcessingException;
 import androidx.media3.common.util.GlProgram;
 import androidx.media3.common.util.GlUtil;
+import androidx.media3.common.util.Log;
 import androidx.media3.common.util.UnstableApi;
+import androidx.media3.common.util.Util;
 import java.io.IOException;
 import java.util.ArrayDeque;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Queue;
+import java.util.concurrent.ExecutorService;
 import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
 
 /**
  * A basic VideoCompositor that takes in frames from exactly 2 input sources and combines it to one
- * output. Only tested for 2 frames in, 1 frame out for now.
+ * output.
  */
 @UnstableApi
 public final class VideoCompositor {
   // TODO: b/262694346 -  Flesh out this implementation by doing the following:
-  //  * Create on a shared VideoFrameProcessingTaskExecutor with VideoFrameProcessor instances.
-  //  * >1 input/output frame per source.
   //  * Handle matched timestamps.
   //  * Handle mismatched timestamps
   //  * Before allowing customization of this class, add an interface, and rename this class to
   //    DefaultCompositor.
 
+  /** Listener for errors. */
+  public interface ErrorListener {
+    /**
+     * Called when an exception occurs during asynchronous frame compositing.
+     *
+     * <p>Using {@code VideoCompositor} after an error happens is undefined behavior.
+     */
+    void onError(VideoFrameProcessingException exception);
+  }
+
+  private static final String THREAD_NAME = "Effect:VideoCompositor:GlThread";
+  private static final String TAG = "VideoCompositor";
   private static final String VERTEX_SHADER_PATH = "shaders/vertex_shader_transformation_es2.glsl";
 
   private static final String FRAGMENT_SHADER_PATH = "shaders/fragment_shader_compositor_es2.glsl";
@@ -55,17 +72,30 @@ public final class VideoCompositor {
   private final Context context;
   private final DefaultVideoFrameProcessor.TextureOutputListener textureOutputListener;
   private final GlObjectsProvider glObjectsProvider;
+  private final VideoFrameProcessingTaskExecutor videoFrameProcessingTaskExecutor;
+
   // List of queues of unprocessed frames for each input source.
+  @GuardedBy("this")
   private final List<Queue<InputFrameInfo>> inputFrameInfos;
 
   private final TexturePool outputTexturePool;
   // Only used on the GL Thread.
+  private @MonotonicNonNull EGLContext eglContext;
+  private @MonotonicNonNull EGLDisplay eglDisplay;
   private @MonotonicNonNull GlProgram glProgram;
   private long syncObject;
 
+  /**
+   * Creates an instance.
+   *
+   * <p>If a non-null {@code executorService} is set, the {@link ExecutorService} must be
+   * {@linkplain ExecutorService#shutdown shut down} by the caller.
+   */
   public VideoCompositor(
       Context context,
       GlObjectsProvider glObjectsProvider,
+      @Nullable ExecutorService executorService,
+      ErrorListener errorListener,
       DefaultVideoFrameProcessor.TextureOutputListener textureOutputListener,
       @IntRange(from = 1) int textureOutputCapacity) {
     this.context = context;
@@ -75,6 +105,16 @@ public final class VideoCompositor {
     inputFrameInfos = new ArrayList<>();
     outputTexturePool =
         new TexturePool(/* useHighPrecisionColorComponents= */ false, textureOutputCapacity);
+
+    boolean ownsExecutor = executorService == null;
+    ExecutorService instanceExecutorService =
+        ownsExecutor ? Util.newSingleThreadExecutor(THREAD_NAME) : checkNotNull(executorService);
+    videoFrameProcessingTaskExecutor =
+        new VideoFrameProcessingTaskExecutor(
+            instanceExecutorService,
+            /* shouldShutdownExecutorService= */ ownsExecutor,
+            errorListener::onError);
+    videoFrameProcessingTaskExecutor.submit(this::setupGlObjects);
   }
 
   /**
@@ -86,7 +126,6 @@ public final class VideoCompositor {
     return inputFrameInfos.size() - 1;
   }
 
-  // Below methods must be called on the GL thread.
   /**
    * Queues an input texture to be composited, for example from an upstream {@link
    * DefaultVideoFrameProcessor.TextureOutputListener}.
@@ -94,7 +133,7 @@ public final class VideoCompositor {
    * <p>Each input source must have a unique {@code inputId} returned from {@link
    * #registerInputSource}.
    */
-  public void queueInputTexture(
+  public synchronized void queueInputTexture(
       int inputId,
       GlTextureInfo inputTexture,
       long presentationTimeUs,
@@ -104,14 +143,35 @@ public final class VideoCompositor {
         new InputFrameInfo(inputTexture, presentationTimeUs, releaseTextureCallback);
     checkNotNull(inputFrameInfos.get(inputId)).add(inputFrameInfo);
 
-    if (isReadyToComposite()) {
+    videoFrameProcessingTaskExecutor.submit(
-      compositeToOutputTexture();
+        () -> {
+          if (isReadyToComposite()) {
+            compositeToOutputTexture();
+          }
+        });
+  }
+
+  public void release() {
+    try {
+      videoFrameProcessingTaskExecutor.release(/* releaseTask= */ this::releaseGlObjects);
+    } catch (InterruptedException e) {
+      Thread.currentThread().interrupt();
+      throw new IllegalStateException(e);
     }
   }
 
-  private boolean isReadyToComposite() {
+  // Below methods must be called on the GL thread.
+  private void setupGlObjects() throws GlUtil.GlException {
+    EGLDisplay eglDisplay = GlUtil.getDefaultEglDisplay();
+    EGLContext eglContext =
+        glObjectsProvider.createEglContext(
+            eglDisplay, /* openGlVersion= */ 2, GlUtil.EGL_CONFIG_ATTRIBUTES_RGBA_8888);
+    glObjectsProvider.createFocusedPlaceholderEglSurface(eglContext, eglDisplay);
+  }
+
+  private synchronized boolean isReadyToComposite() {
     // TODO: b/262694346 - Use timestamps to determine when to composite instead of number of
-    // frames.
+    //  frames.
     for (int inputId = 0; inputId < inputFrameInfos.size(); inputId++) {
       if (checkNotNull(inputFrameInfos.get(inputId)).isEmpty()) {
         return false;
@@ -120,13 +180,14 @@ public final class VideoCompositor {
     return true;
   }
 
-  private void compositeToOutputTexture() throws VideoFrameProcessingException {
+  private synchronized void compositeToOutputTexture() throws VideoFrameProcessingException {
     List<InputFrameInfo> framesToComposite = new ArrayList<>();
     for (int inputId = 0; inputId < inputFrameInfos.size(); inputId++) {
       framesToComposite.add(checkNotNull(inputFrameInfos.get(inputId)).remove());
     }
 
     ensureGlProgramConfigured();
+
     // TODO: b/262694346 -
     //  * Support an arbitrary number of inputs.
     //  * Allow different frame dimensions.
@@ -150,8 +211,9 @@ public final class VideoCompositor {
       // TODO: b/262694346 - Use presentationTimeUs here for freeing textures.
       textureOutputListener.onTextureRendered(
           checkNotNull(outputTexture),
-          /* presentationTimeUs= */ 0,
+          /* presentationTimeUs= */ framesToComposite.get(0).presentationTimeUs,
-          (presentationTimeUs) -> outputTexturePool.freeTexture(),
+          (presentationTimeUs) ->
+              videoFrameProcessingTaskExecutor.submit(outputTexturePool::freeTexture),
           syncObject);
     } catch (GlUtil.GlException e) {
       throw VideoFrameProcessingException.from(e);
@@ -194,6 +256,24 @@ public final class VideoCompositor {
     glProgram.bindAttributesAndUniforms();
     // The four-vertex triangle strip forms a quad.
     GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, /* first= */ 0, /* count= */ 4);
+    GlUtil.checkGlError();
+  }
+
+  private void releaseGlObjects() {
+    try {
+      outputTexturePool.deleteAllTextures();
+      if (glProgram != null) {
+        glProgram.delete();
+      }
+    } catch (Exception e) {
+      Log.e(TAG, "Error releasing GL resources", e);
+    } finally {
+      try {
+        GlUtil.destroyEglContext(eglDisplay, eglContext);
+      } catch (GlUtil.GlException e) {
+        Log.e(TAG, "Error releasing GL context", e);
+      }
+    }
   }
 
   /** Holds information on a frame and how to release it. */

libraries/effect/src/main/java/androidx/media3/effect/VideoFrameProcessingTaskExecutor.java

@@ -20,7 +20,6 @@ import static java.util.concurrent.TimeUnit.MILLISECONDS;
 import androidx.annotation.GuardedBy;
 import androidx.annotation.Nullable;
 import androidx.media3.common.VideoFrameProcessingException;
-import androidx.media3.common.VideoFrameProcessor;
 import androidx.media3.common.util.GlUtil;
 import androidx.media3.common.util.UnstableApi;
 import java.util.ArrayDeque;
@@ -36,11 +35,8 @@ import java.util.concurrent.RejectedExecutionException;
  *
  * <p>Public methods can be called from any thread.
  *
- * <p>The wrapper handles calling {@link
+ * <p>Calls {@link ErrorListener#onError} for errors that occur during these tasks. The listener is
- * VideoFrameProcessor.Listener#onError(VideoFrameProcessingException)} for errors that occur during
+ * invoked from the {@link ExecutorService}.
- * these tasks. The listener is invoked from the {@link ExecutorService}. Errors are assumed to be
- * non-recoverable, so the {@code VideoFrameProcessingTaskExecutor} should be released if an error
- * occurs.
  *
  * <p>{@linkplain #submitWithHighPriority(Task) High priority tasks} are always executed before
  * {@linkplain #submit(Task) default priority tasks}. Tasks with equal priority are executed in FIFO
@@ -52,16 +48,27 @@ import java.util.concurrent.RejectedExecutionException;
    * Interface for tasks that may throw a {@link GlUtil.GlException} or {@link
    * VideoFrameProcessingException}.
    */
-  public interface Task {
+  interface Task {
     /** Runs the task. */
     void run() throws VideoFrameProcessingException, GlUtil.GlException;
   }
 
+  /** Listener for errors. */
+  interface ErrorListener {
+    /**
+     * Called when an exception occurs while executing submitted tasks.
+     *
+     * <p>Using the {@link VideoFrameProcessingTaskExecutor} after an error happens is undefined
+     * behavior.
+     */
+    void onError(VideoFrameProcessingException exception);
+  }
+
   private static final long RELEASE_WAIT_TIME_MS = 500;
 
   private final boolean shouldShutdownExecutorService;
   private final ExecutorService singleThreadExecutorService;
-  private final VideoFrameProcessor.Listener listener;
+  private final ErrorListener errorListener;
   private final Object lock;
 
   @GuardedBy("lock")
@@ -74,10 +81,10 @@ import java.util.concurrent.RejectedExecutionException;
   public VideoFrameProcessingTaskExecutor(
       ExecutorService singleThreadExecutorService,
       boolean shouldShutdownExecutorService,
-      VideoFrameProcessor.Listener listener) {
+      ErrorListener errorListener) {
     this.singleThreadExecutorService = singleThreadExecutorService;
     this.shouldShutdownExecutorService = shouldShutdownExecutorService;
-    this.listener = listener;
+    this.errorListener = errorListener;
     lock = new Object();
     highPriorityTasks = new ArrayDeque<>();
   }
@@ -186,7 +193,7 @@ import java.util.concurrent.RejectedExecutionException;
     if (shouldShutdownExecutorService) {
       singleThreadExecutorService.shutdown();
       if (!singleThreadExecutorService.awaitTermination(RELEASE_WAIT_TIME_MS, MILLISECONDS)) {
-        listener.onError(
+        errorListener.onError(
             new VideoFrameProcessingException(
                 "Release timed out. OpenGL resources may not be cleaned up properly."));
       }
@@ -231,6 +238,6 @@ import java.util.concurrent.RejectedExecutionException;
       }
       shouldCancelTasks = true;
     }
-    listener.onError(VideoFrameProcessingException.from(exception));
+    errorListener.onError(VideoFrameProcessingException.from(exception));
   }
 }

libraries/effect/src/test/java/androidx/media3/effect/ChainingGlShaderProgramListenerTest.java

@@ -21,7 +21,6 @@ import static org.mockito.Mockito.verify;
 import androidx.media3.common.C;
 import androidx.media3.common.GlObjectsProvider;
 import androidx.media3.common.GlTextureInfo;
-import androidx.media3.common.VideoFrameProcessor;
 import androidx.media3.common.util.Util;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 import org.junit.After;
@@ -33,13 +32,13 @@ import org.junit.runner.RunWith;
 public final class ChainingGlShaderProgramListenerTest {
   private static final long EXECUTOR_WAIT_TIME_MS = 100;
 
-  private final VideoFrameProcessor.Listener mockFrameProcessorListener =
+  private final VideoFrameProcessingTaskExecutor.ErrorListener mockErrorListener =
-      mock(VideoFrameProcessor.Listener.class);
+      mock(VideoFrameProcessingTaskExecutor.ErrorListener.class);
   private final VideoFrameProcessingTaskExecutor videoFrameProcessingTaskExecutor =
       new VideoFrameProcessingTaskExecutor(
           Util.newSingleThreadExecutor("Test"),
           /* shouldShutdownExecutorService= */ true,
-          mockFrameProcessorListener);
+          mockErrorListener);
   private final GlObjectsProvider mockGlObjectsProvider = mock(GlObjectsProvider.class);
   private final GlShaderProgram mockProducingGlShaderProgram = mock(GlShaderProgram.class);
   private final GlShaderProgram mockConsumingGlShaderProgram = mock(GlShaderProgram.class);

libraries/test_utils/src/main/java/androidx/media3/test/utils/VideoFrameProcessorTestRunner.java

@@ -242,7 +242,7 @@ public final class VideoFrameProcessorTestRunner {
    * Time to wait for the decoded frame to populate the {@link VideoFrameProcessor} instance's input
    * surface and the {@link VideoFrameProcessor} to finish processing the frame, in milliseconds.
    */
-  public static final int VIDEO_FRAME_PROCESSING_WAIT_MS = 5000;
+  public static final int VIDEO_FRAME_PROCESSING_WAIT_MS = 5_000;
 
   private final String testId;
   private final @MonotonicNonNull String videoAssetPath;

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

@@ -557,11 +557,11 @@ public final class AndroidTestUtil {
    */
   public static EGLContext createOpenGlObjects() throws GlUtil.GlException {
     EGLDisplay eglDisplay = GlUtil.getDefaultEglDisplay();
-    int[] configAttributes = GlUtil.EGL_CONFIG_ATTRIBUTES_RGBA_8888;
     GlObjectsProvider glObjectsProvider =
         new DefaultGlObjectsProvider(/* sharedEglContext= */ null);
     EGLContext eglContext =
-        glObjectsProvider.createEglContext(eglDisplay, /* openGlVersion= */ 2, configAttributes);
+        glObjectsProvider.createEglContext(
+            eglDisplay, /* openGlVersion= */ 2, GlUtil.EGL_CONFIG_ATTRIBUTES_RGBA_8888);
     glObjectsProvider.createFocusedPlaceholderEglSurface(eglContext, eglDisplay);
     return eglContext;
   }

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

@@ -87,7 +87,7 @@ public final class TextureBitmapReader implements VideoFrameProcessorTestRunner.
       GlTextureInfo outputTexture,
       long presentationTimeUs,
       DefaultVideoFrameProcessor.ReleaseOutputTextureCallback releaseOutputTextureCallback)
-      throws VideoFrameProcessingException, GlUtil.GlException {
+      throws VideoFrameProcessingException {
     readBitmap(outputTexture, presentationTimeUs);
     releaseOutputTextureCallback.release(presentationTimeUs);
   }

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

@@ -43,6 +43,10 @@ import androidx.media3.test.utils.BitmapPixelTestUtil;
 import androidx.media3.test.utils.VideoFrameProcessorTestRunner;
 import com.google.common.collect.ImmutableList;
 import java.io.IOException;
+import java.util.List;
+import java.util.Set;
+import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.atomic.AtomicReference;
 import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
@@ -55,8 +59,6 @@ import org.junit.runners.Parameterized;
 /** Pixel test for {@link VideoCompositor} compositing 2 input frames into 1 output frame. */
 @RunWith(Parameterized.class)
 public final class VideoCompositorPixelTest {
-  private @MonotonicNonNull VideoFrameProcessorTestRunner inputVfpTestRunner1;
-  private @MonotonicNonNull VideoFrameProcessorTestRunner inputVfpTestRunner2;
 
   private static final String ORIGINAL_PNG_ASSET_PATH = "media/bitmap/input_images/media3test.png";
   private static final String GRAYSCALE_PNG_ASSET_PATH =
@@ -66,10 +68,6 @@ public final class VideoCompositorPixelTest {
   private static final String GRAYSCALE_AND_ROTATE180_COMPOSITE_PNG_ASSET_PATH =
       "media/bitmap/sample_mp4_first_frame/electrical_colors/grayscaleAndRotate180Composite.png";
 
-  private static final Effect ROTATE_180 =
-      new ScaleAndRotateTransformation.Builder().setRotationDegrees(180).build();
-  private static final Effect GRAYSCALE = RgbFilter.createGrayscaleFilter();
-
   @Parameterized.Parameters(name = "useSharedExecutor={0}")
   public static ImmutableList<Boolean> useSharedExecutor() {
     return ImmutableList.of(true, false);
@@ -77,48 +75,26 @@ public final class VideoCompositorPixelTest {
 
   @Parameterized.Parameter public boolean useSharedExecutor;
 
-  public @Nullable ExecutorService executorService;
+  private @MonotonicNonNull VideoCompositorTestRunner videoCompositorTestRunner;
 
   @After
   public void tearDown() {
-    if (inputVfpTestRunner1 != null) {
+    if (videoCompositorTestRunner != null) {
-      inputVfpTestRunner1.release();
+      videoCompositorTestRunner.release();
-    }
-    if (inputVfpTestRunner2 != null) {
-      inputVfpTestRunner2.release();
-    }
-
-    if (executorService != null) {
-      try {
-        executorService.shutdown();
-        if (!executorService.awaitTermination(/* timeout= */ 5000, MILLISECONDS)) {
-          throw new IllegalStateException("Missed shutdown timeout.");
-        }
-      } catch (InterruptedException unexpected) {
-        Thread.currentThread().interrupt();
-        throw new IllegalStateException(unexpected);
-      }
     }
   }
 
   @Test
-  public void compositeTwoFrames_matchesExpected() throws Exception {
+  public void compositeTwoInputs_withOneFrameFromEach_matchesExpectedBitmap() throws Exception {
     String testId =
-        "compositeTwoFrames_matchesExpected[useSharedExecutor=" + useSharedExecutor + "]";
+        "compositeTwoInputs_withOneFrameFromEach_matchesExpectedBitmap[useSharedExecutor="
-    executorService = useSharedExecutor ? Util.newSingleThreadExecutor("Effect:GlThread") : null;
+            + useSharedExecutor
-
+            + "]";
-    // Arrange VideoCompositor and VideoFrameProcessor instances.
-    EGLContext sharedEglContext = AndroidTestUtil.createOpenGlObjects();
-    GlObjectsProvider sharedGlObjectsProvider = new DefaultGlObjectsProvider(sharedEglContext);
     AtomicReference<Bitmap> compositedOutputBitmap = new AtomicReference<>();
-    VideoCompositor videoCompositor =
+    videoCompositorTestRunner =
-        new VideoCompositor(
+        new VideoCompositorTestRunner(
-            getApplicationContext(),
+            testId,
-            sharedGlObjectsProvider,
+            (outputTexture, presentationTimeUs, releaseOutputTextureCallback, syncObject) -> {
-            /* textureOutputListener= */ (outputTexture,
-                presentationTimeUs,
-                releaseOutputTextureCallback,
-                syncObject) -> {
               try {
                 if (useSharedExecutor) {
                   GlUtil.deleteSyncObject(syncObject);
@@ -134,65 +110,228 @@ public final class VideoCompositorPixelTest {
                 releaseOutputTextureCallback.release(presentationTimeUs);
               }
             },
-            /* textureOutputCapacity= */ 1);
+            useSharedExecutor);
-    TextureBitmapReader inputTextureBitmapReader1 = new TextureBitmapReader();
-    VideoFrameProcessorTestRunner inputVfpTestRunner1 =
-        getFrameProcessorTestRunnerBuilder(
-                testId,
-                inputTextureBitmapReader1,
-                videoCompositor,
-                executorService,
-                sharedGlObjectsProvider)
-            .setEffects(GRAYSCALE)
-            .build();
-    this.inputVfpTestRunner1 = inputVfpTestRunner1;
-    TextureBitmapReader inputTextureBitmapReader2 = new TextureBitmapReader();
-    VideoFrameProcessorTestRunner inputVfpTestRunner2 =
-        getFrameProcessorTestRunnerBuilder(
-                testId,
-                inputTextureBitmapReader2,
-                videoCompositor,
-                executorService,
-                sharedGlObjectsProvider)
-            .setEffects(ROTATE_180)
-            .build();
-    this.inputVfpTestRunner2 = inputVfpTestRunner2;
 
-    // Queue 1 input bitmap from each input VideoFrameProcessor source.
+    videoCompositorTestRunner.queueBitmapsToBothInputs(/* count= */ 1);
-    inputVfpTestRunner1.queueInputBitmap(
-        readBitmap(ORIGINAL_PNG_ASSET_PATH),
-        /* durationUs= */ 1 * C.MICROS_PER_SECOND,
-        /* offsetToAddUs= */ 0,
-        /* frameRate= */ 1);
-    inputVfpTestRunner1.endFrameProcessing();
-    inputVfpTestRunner2.queueInputBitmap(
-        readBitmap(ORIGINAL_PNG_ASSET_PATH),
-        /* durationUs= */ 1 * C.MICROS_PER_SECOND,
-        /* offsetToAddUs= */ 0,
-        /* frameRate= */ 1);
-    inputVfpTestRunner2.endFrameProcessing();
 
-    // Check that VideoFrameProcessor and VideoCompositor outputs match expected bitmaps.
+    Bitmap actualCompositorInputBitmap1 = videoCompositorTestRunner.inputBitmapReader1.getBitmap();
-    Bitmap actualCompositorInputBitmap1 = checkNotNull(inputTextureBitmapReader1).getBitmap();
     saveAndAssertBitmapMatchesExpected(
         testId,
         actualCompositorInputBitmap1,
         /* actualBitmapLabel= */ "actualCompositorInputBitmap1",
         GRAYSCALE_PNG_ASSET_PATH);
-    Bitmap actualCompositorInputBitmap2 = checkNotNull(inputTextureBitmapReader2).getBitmap();
+    Bitmap actualCompositorInputBitmap2 = videoCompositorTestRunner.inputBitmapReader2.getBitmap();
     saveAndAssertBitmapMatchesExpected(
         testId,
         actualCompositorInputBitmap2,
         /* actualBitmapLabel= */ "actualCompositorInputBitmap2",
         ROTATE180_PNG_ASSET_PATH);
-    Bitmap compositorOutputBitmap = compositedOutputBitmap.get();
     saveAndAssertBitmapMatchesExpected(
         testId,
-        compositorOutputBitmap,
+        compositedOutputBitmap.get(),
         /* actualBitmapLabel= */ "compositorOutputBitmap",
         GRAYSCALE_AND_ROTATE180_COMPOSITE_PNG_ASSET_PATH);
   }
 
+  @Test
+  public void compositeTwoInputs_withFiveFramesFromEach_matchesExpectedTimestamps()
+      throws Exception {
+    String testId =
+        "compositeTwoInputs_withFiveFramesFromEach_matchesExpectedTimestamps[useSharedExecutor="
+            + useSharedExecutor
+            + "]";
+    List<Long> compositorTimestamps = new CopyOnWriteArrayList<>();
+
+    AtomicReference<Bitmap> compositedFirstOutputBitmap = new AtomicReference<>();
+    videoCompositorTestRunner =
+        new VideoCompositorTestRunner(
+            testId,
+            (outputTexture, presentationTimeUs, releaseOutputTextureCallback, syncObject) -> {
+              try {
+                if (useSharedExecutor) {
+                  GlUtil.deleteSyncObject(syncObject);
+                } else {
+                  GlUtil.awaitSyncObject(syncObject);
+                }
+                if (compositedFirstOutputBitmap.get() == null) {
+                  compositedFirstOutputBitmap.set(
+                      BitmapPixelTestUtil.createArgb8888BitmapFromFocusedGlFramebuffer(
+                          outputTexture.width, outputTexture.height));
+                }
+                compositorTimestamps.add(presentationTimeUs);
+              } catch (GlUtil.GlException e) {
+                throw VideoFrameProcessingException.from(e);
+              } finally {
+                releaseOutputTextureCallback.release(presentationTimeUs);
+              }
+            },
+            useSharedExecutor);
+
+    videoCompositorTestRunner.queueBitmapsToBothInputs(/* count= */ 5);
+
+    ImmutableList<Long> expectedTimestamps =
+        ImmutableList.of(
+            0L,
+            1L * C.MICROS_PER_SECOND,
+            2L * C.MICROS_PER_SECOND,
+            3L * C.MICROS_PER_SECOND,
+            4L * C.MICROS_PER_SECOND);
+    Set<Long> inputTimestampsSource1 =
+        videoCompositorTestRunner.inputBitmapReader1.getOutputTimestamps();
+    assertThat(inputTimestampsSource1).containsExactlyElementsIn(expectedTimestamps).inOrder();
+    Set<Long> inputTimestampsSource2 =
+        videoCompositorTestRunner.inputBitmapReader2.getOutputTimestamps();
+    assertThat(inputTimestampsSource2).containsExactlyElementsIn(expectedTimestamps).inOrder();
+    assertThat(compositorTimestamps).containsExactlyElementsIn(expectedTimestamps).inOrder();
+    saveAndAssertBitmapMatchesExpected(
+        testId,
+        compositedFirstOutputBitmap.get(),
+        /* actualBitmapLabel= */ "compositorOutputBitmap",
+        GRAYSCALE_AND_ROTATE180_COMPOSITE_PNG_ASSET_PATH);
+  }
+
+  /**
+   * A test runner for {@link VideoCompositor tests} tests.
+   *
+   * <p>Composites input bitmaps from two input sources.
+   */
+  private static final class VideoCompositorTestRunner {
+    private static final int COMPOSITOR_TIMEOUT_MS = 5_000;
+    private static final Effect ROTATE_180_EFFECT =
+        new ScaleAndRotateTransformation.Builder().setRotationDegrees(180).build();
+    private static final Effect GRAYSCALE_EFFECT = RgbFilter.createGrayscaleFilter();
+
+    public final TextureBitmapReader inputBitmapReader1;
+    public final TextureBitmapReader inputBitmapReader2;
+    private final VideoFrameProcessorTestRunner inputVideoFrameProcessorTestRunner1;
+    private final VideoFrameProcessorTestRunner inputVideoFrameProcessorTestRunner2;
+    private final VideoCompositor videoCompositor;
+    private final @Nullable ExecutorService sharedExecutorService;
+    private final AtomicReference<VideoFrameProcessingException> compositionException;
+    private @MonotonicNonNull CountDownLatch compositorEnded;
+
+    public VideoCompositorTestRunner(
+        String testId,
+        DefaultVideoFrameProcessor.TextureOutputListener compositorTextureOutputListener,
+        boolean useSharedExecutor)
+        throws GlUtil.GlException, VideoFrameProcessingException {
+      sharedExecutorService =
+          useSharedExecutor ? Util.newSingleThreadExecutor("Effect:Shared:GlThread") : null;
+      EGLContext sharedEglContext = AndroidTestUtil.createOpenGlObjects();
+      GlObjectsProvider glObjectsProvider =
+          new DefaultGlObjectsProvider(
+              /* sharedEglContext= */ useSharedExecutor ? null : sharedEglContext);
+
+      compositionException = new AtomicReference<>();
+      videoCompositor =
+          new VideoCompositor(
+              getApplicationContext(),
+              glObjectsProvider,
+              sharedExecutorService,
+              /* errorListener= */ compositionException::set,
+              (outputTexture, presentationTimeUs, releaseOutputTextureCallback, syncObject) -> {
+                compositorTextureOutputListener.onTextureRendered(
+                    outputTexture, presentationTimeUs, releaseOutputTextureCallback, syncObject);
+                checkNotNull(compositorEnded).countDown();
+              },
+              /* textureOutputCapacity= */ 1);
+      inputBitmapReader1 = new TextureBitmapReader();
+      inputVideoFrameProcessorTestRunner1 =
+          createVideoFrameProcessorTestRunnerBuilder(
+                  testId,
+                  inputBitmapReader1,
+                  videoCompositor,
+                  sharedExecutorService,
+                  glObjectsProvider)
+              .setEffects(GRAYSCALE_EFFECT)
+              .build();
+      inputBitmapReader2 = new TextureBitmapReader();
+      inputVideoFrameProcessorTestRunner2 =
+          createVideoFrameProcessorTestRunnerBuilder(
+                  testId,
+                  inputBitmapReader2,
+                  videoCompositor,
+                  sharedExecutorService,
+                  glObjectsProvider)
+              .setEffects(ROTATE_180_EFFECT)
+              .build();
+    }
+
+    /**
+     * Queues {@code count} bitmaps, with one bitmap per second, starting from and including 0
+     * seconds.
+     */
+    public void queueBitmapsToBothInputs(int count) throws IOException, InterruptedException {
+      compositorEnded = new CountDownLatch(count);
+      inputVideoFrameProcessorTestRunner1.queueInputBitmap(
+          readBitmap(ORIGINAL_PNG_ASSET_PATH),
+          /* durationUs= */ count * C.MICROS_PER_SECOND,
+          /* offsetToAddUs= */ 0,
+          /* frameRate= */ 1);
+      inputVideoFrameProcessorTestRunner2.queueInputBitmap(
+          readBitmap(ORIGINAL_PNG_ASSET_PATH),
+          /* durationUs= */ count * C.MICROS_PER_SECOND,
+          /* offsetToAddUs= */ 0,
+          /* frameRate= */ 1);
+      inputVideoFrameProcessorTestRunner1.endFrameProcessing();
+      inputVideoFrameProcessorTestRunner2.endFrameProcessing();
+      compositorEnded.await(COMPOSITOR_TIMEOUT_MS, MILLISECONDS);
+
+      assertThat(compositionException.get()).isNull();
+    }
+
+    public void release() {
+      inputVideoFrameProcessorTestRunner1.release();
+      inputVideoFrameProcessorTestRunner2.release();
+      videoCompositor.release();
+
+      if (sharedExecutorService != null) {
+        try {
+          sharedExecutorService.shutdown();
+          if (!sharedExecutorService.awaitTermination(COMPOSITOR_TIMEOUT_MS, MILLISECONDS)) {
+            throw new IllegalStateException("Missed shutdown timeout.");
+          }
+        } catch (InterruptedException unexpected) {
+          Thread.currentThread().interrupt();
+          throw new IllegalStateException(unexpected);
+        }
+      }
+    }
+
+    private static VideoFrameProcessorTestRunner.Builder createVideoFrameProcessorTestRunnerBuilder(
+        String testId,
+        TextureBitmapReader textureBitmapReader,
+        VideoCompositor videoCompositor,
+        @Nullable ExecutorService executorService,
+        GlObjectsProvider glObjectsProvider) {
+      int inputId = videoCompositor.registerInputSource();
+      DefaultVideoFrameProcessor.Factory.Builder defaultVideoFrameProcessorFactoryBuilder =
+          new DefaultVideoFrameProcessor.Factory.Builder()
+              .setGlObjectsProvider(glObjectsProvider)
+              .setTextureOutput(
+                  /* textureOutputListener= */ (GlTextureInfo outputTexture,
+                      long presentationTimeUs,
+                      DefaultVideoFrameProcessor.ReleaseOutputTextureCallback
+                          releaseOutputTextureCallback,
+                      long syncObject) -> {
+                    GlUtil.awaitSyncObject(syncObject);
+                    textureBitmapReader.readBitmap(outputTexture, presentationTimeUs);
+                    videoCompositor.queueInputTexture(
+                        inputId, outputTexture, presentationTimeUs, releaseOutputTextureCallback);
+                  },
+                  /* textureOutputCapacity= */ 1);
+      if (executorService != null) {
+        defaultVideoFrameProcessorFactoryBuilder.setExecutorService(executorService);
+      }
+      return new VideoFrameProcessorTestRunner.Builder()
+          .setTestId(testId)
+          .setVideoFrameProcessorFactory(defaultVideoFrameProcessorFactoryBuilder.build())
+          .setInputType(INPUT_TYPE_BITMAP)
+          .setInputColorInfo(ColorInfo.SRGB_BT709_FULL)
+          .setBitmapReader(textureBitmapReader);
+    }
+  }
+
   private void saveAndAssertBitmapMatchesExpected(
       String testId, Bitmap actualBitmap, String actualBitmapLabel, String expectedBitmapAssetPath)
       throws IOException {
@@ -203,37 +342,4 @@ public final class VideoCompositorPixelTest {
     assertThat(averagePixelAbsoluteDifference)
         .isAtMost(MAXIMUM_AVERAGE_PIXEL_ABSOLUTE_DIFFERENCE_DIFFERENT_DEVICE);
   }
-
-  private static VideoFrameProcessorTestRunner.Builder getFrameProcessorTestRunnerBuilder(
-      String testId,
-      TextureBitmapReader textureBitmapReader,
-      VideoCompositor videoCompositor,
-      @Nullable ExecutorService executorService,
-      GlObjectsProvider glObjectsProvider) {
-    int inputId = videoCompositor.registerInputSource();
-    DefaultVideoFrameProcessor.Factory.Builder defaultVideoFrameProcessorFactoryBuilder =
-        new DefaultVideoFrameProcessor.Factory.Builder()
-            .setGlObjectsProvider(glObjectsProvider)
-            .setTextureOutput(
-                /* textureOutputListener= */ (GlTextureInfo outputTexture,
-                    long presentationTimeUs,
-                    DefaultVideoFrameProcessor.ReleaseOutputTextureCallback
-                        releaseOutputTextureCallback,
-                    long syncObject) -> {
-                  GlUtil.awaitSyncObject(syncObject);
-                  textureBitmapReader.readBitmap(outputTexture, presentationTimeUs);
-                  videoCompositor.queueInputTexture(
-                      inputId, outputTexture, presentationTimeUs, releaseOutputTextureCallback);
-                },
-                /* textureOutputCapacity= */ 1);
-    if (executorService != null) {
-      defaultVideoFrameProcessorFactoryBuilder.setExecutorService(executorService);
-    }
-    return new VideoFrameProcessorTestRunner.Builder()
-        .setTestId(testId)
-        .setVideoFrameProcessorFactory(defaultVideoFrameProcessorFactoryBuilder.build())
-        .setInputType(INPUT_TYPE_BITMAP)
-        .setInputColorInfo(ColorInfo.SRGB_BT709_FULL)
-        .setBitmapReader(textureBitmapReader);
-  }
 }