Add FrameProcessorChain factory method and make constructor private.

PiperOrigin-RevId: 438804850

library/transformer/src/androidTest/java/com/google/android/exoplayer2/transformer/FrameProcessorChainPixelTest.java

@@ -246,7 +246,7 @@ public final class FrameProcessorChainPixelTest {
       int inputWidth = checkNotNull(mediaFormat).getInteger(MediaFormat.KEY_WIDTH);
       int inputHeight = mediaFormat.getInteger(MediaFormat.KEY_HEIGHT);
       frameProcessorChain =
-          new FrameProcessorChain(
+          FrameProcessorChain.create(
               context,
               PIXEL_WIDTH_HEIGHT_RATIO,
               inputWidth,

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

@@ -63,6 +63,49 @@ import org.checkerframework.checker.nullness.qual.RequiresNonNull;
     GlUtil.glAssertionsEnabled = true;
   }
 
+  /**
+   * Creates a new instance.
+   *
+   * @param context A {@link Context}.
+   * @param pixelWidthHeightRatio The ratio of width over height, for each pixel.
+   * @param inputWidth The input frame width, in pixels.
+   * @param inputHeight The input frame height, in pixels.
+   * @param frameProcessors The {@link GlFrameProcessor GlFrameProcessors} to apply to each frame.
+   * @param enableExperimentalHdrEditing Whether to attempt to process the input as an HDR signal.
+   * @return A new instance.
+   * @throws TransformationException If the {@code pixelWidthHeightRatio} isn't 1.
+   */
+  public static FrameProcessorChain create(
+      Context context,
+      float pixelWidthHeightRatio,
+      int inputWidth,
+      int inputHeight,
+      List<GlFrameProcessor> frameProcessors,
+      boolean enableExperimentalHdrEditing)
+      throws TransformationException {
+    if (pixelWidthHeightRatio != 1.0f) {
+      // TODO(b/211782176): Consider implementing support for non-square pixels.
+      throw TransformationException.createForFrameProcessorChain(
+          new UnsupportedOperationException(
+              "Transformer's FrameProcessorChain currently does not support frame edits on"
+                  + " non-square pixels. The pixelWidthHeightRatio is: "
+                  + pixelWidthHeightRatio),
+          TransformationException.ERROR_CODE_GL_INIT_FAILED);
+    }
+
+    ExternalCopyFrameProcessor externalCopyFrameProcessor =
+        new ExternalCopyFrameProcessor(context, enableExperimentalHdrEditing);
+    externalCopyFrameProcessor.setInputSize(inputWidth, inputHeight);
+    Size inputSize = externalCopyFrameProcessor.getOutputSize();
+    for (int i = 0; i < frameProcessors.size(); i++) {
+      frameProcessors.get(i).setInputSize(inputSize.getWidth(), inputSize.getHeight());
+      inputSize = frameProcessors.get(i).getOutputSize();
+    }
+
+    return new FrameProcessorChain(
+        externalCopyFrameProcessor, frameProcessors, enableExperimentalHdrEditing);
+  }
+
   private static final String THREAD_NAME = "Transformer:FrameProcessorChain";
 
   private final boolean enableExperimentalHdrEditing;
@@ -78,7 +121,6 @@ import org.checkerframework.checker.nullness.qual.RequiresNonNull;
   private volatile boolean releaseRequested;
 
   private boolean inputStreamEnded;
-  private final Size inputSize;
   /** Wraps the {@link #inputSurfaceTexture}. */
   private @MonotonicNonNull Surface inputSurface;
   /** Associated with an OpenGL external texture. */
@@ -116,48 +158,23 @@ import org.checkerframework.checker.nullness.qual.RequiresNonNull;
    */
   private @MonotonicNonNull EGLSurface debugPreviewEglSurface;
 
-  /**
+  private FrameProcessorChain(
-   * Creates a new instance.
+      ExternalCopyFrameProcessor externalCopyFrameProcessor,
-   *
-   * @param context A {@link Context}.
-   * @param pixelWidthHeightRatio The ratio of width over height, for each pixel.
-   * @param inputWidth The input frame width, in pixels.
-   * @param inputHeight The input frame height, in pixels.
-   * @param frameProcessors The {@link GlFrameProcessor GlFrameProcessors} to apply to each frame.
-   * @param enableExperimentalHdrEditing Whether to attempt to process the input as an HDR signal.
-   * @throws TransformationException If the {@code pixelWidthHeightRatio} isn't 1.
-   */
-  public FrameProcessorChain(
-      Context context,
-      float pixelWidthHeightRatio,
-      int inputWidth,
-      int inputHeight,
       List<GlFrameProcessor> frameProcessors,
-      boolean enableExperimentalHdrEditing)
+      boolean enableExperimentalHdrEditing) {
-      throws TransformationException {
+    this.externalCopyFrameProcessor = externalCopyFrameProcessor;
-    if (pixelWidthHeightRatio != 1.0f) {
-      // TODO(b/211782176): Consider implementing support for non-square pixels.
-      throw TransformationException.createForFrameProcessorChain(
-          new UnsupportedOperationException(
-              "Transformer's FrameProcessorChain currently does not support frame edits on"
-                  + " non-square pixels. The pixelWidthHeightRatio is: "
-                  + pixelWidthHeightRatio),
-          TransformationException.ERROR_CODE_GL_INIT_FAILED);
-    }
-
-    this.enableExperimentalHdrEditing = enableExperimentalHdrEditing;
     this.frameProcessors = ImmutableList.copyOf(frameProcessors);
+    this.enableExperimentalHdrEditing = enableExperimentalHdrEditing;
 
     singleThreadExecutorService = Util.newSingleThreadExecutor(THREAD_NAME);
     futures = new ConcurrentLinkedQueue<>();
     pendingFrameCount = new AtomicInteger();
-    inputSize = new Size(inputWidth, inputHeight);
     textureTransformMatrix = new float[16];
-    externalCopyFrameProcessor =
-        new ExternalCopyFrameProcessor(context, enableExperimentalHdrEditing);
     framebuffers = new int[frameProcessors.size()];
-    configureFrameProcessorSizes(inputSize, frameProcessors);
+    outputSize =
-    outputSize = frameProcessors.isEmpty() ? inputSize : getLast(frameProcessors).getOutputSize();
+        frameProcessors.isEmpty()
+            ? externalCopyFrameProcessor.getOutputSize()
+            : getLast(frameProcessors).getOutputSize();
     debugPreviewWidth = C.LENGTH_UNSET;
     debugPreviewHeight = C.LENGTH_UNSET;
   }
@@ -380,10 +397,9 @@ import org.checkerframework.checker.nullness.qual.RequiresNonNull;
     }
 
     inputExternalTexId = GlUtil.createExternalTexture();
-    externalCopyFrameProcessor.setInputSize(inputSize.getWidth(), inputSize.getHeight());
     externalCopyFrameProcessor.initialize(inputExternalTexId);
 
-    Size intermediateSize = inputSize;
+    Size intermediateSize = externalCopyFrameProcessor.getOutputSize();
     for (int i = 0; i < frameProcessors.size(); i++) {
       int inputTexId =
           GlUtil.createTexture(intermediateSize.getWidth(), intermediateSize.getHeight());
@@ -411,13 +427,14 @@ import org.checkerframework.checker.nullness.qual.RequiresNonNull;
       GlUtil.focusEglSurface(
           eglDisplay, eglContext, eglSurface, outputSize.getWidth(), outputSize.getHeight());
     } else {
+      Size intermediateSize = externalCopyFrameProcessor.getOutputSize();
       GlUtil.focusFramebuffer(
           eglDisplay,
           eglContext,
           eglSurface,
           framebuffers[0],
-          inputSize.getWidth(),
+          intermediateSize.getWidth(),
-          inputSize.getHeight());
+          intermediateSize.getHeight());
     }
     inputSurfaceTexture.updateTexImage();
     inputSurfaceTexture.getTransformMatrix(textureTransformMatrix);
@@ -466,16 +483,4 @@ import org.checkerframework.checker.nullness.qual.RequiresNonNull;
     GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
     GlUtil.checkGlError();
   }
-
-  /**
-   * Configures the input and output {@linkplain Size sizes} of a list of {@link GlFrameProcessor
-   * GlFrameProcessors}.
-   */
-  private static void configureFrameProcessorSizes(
-      Size inputSize, List<GlFrameProcessor> frameProcessors) {
-    for (int i = 0; i < frameProcessors.size(); i++) {
-      frameProcessors.get(i).setInputSize(inputSize.getWidth(), inputSize.getHeight());
-      inputSize = frameProcessors.get(i).getOutputSize();
-    }
-  }
 }

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

@@ -81,7 +81,7 @@ import org.checkerframework.dataflow.qual.Pure;
             .setResolution(transformationRequest.outputHeight)
             .build();
     frameProcessorChain =
-        new FrameProcessorChain(
+        FrameProcessorChain.create(
             context,
             inputFormat.pixelWidthHeightRatio,
             /* inputWidth= */ decodedWidth,

library/transformer/src/test/java/com/google/android/exoplayer2/transformer/FrameProcessorChainTest.java

@@ -37,11 +37,11 @@ import org.junit.runner.RunWith;
 public final class FrameProcessorChainTest {
 
   @Test
-  public void construct_withSupportedPixelWidthHeightRatio_completesSuccessfully()
+  public void create_withSupportedPixelWidthHeightRatio_completesSuccessfully()
       throws TransformationException {
     Context context = getApplicationContext();
 
-    new FrameProcessorChain(
+    FrameProcessorChain.create(
         context,
         /* pixelWidthHeightRatio= */ 1,
         /* inputWidth= */ 200,
@@ -51,14 +51,14 @@ public final class FrameProcessorChainTest {
   }
 
   @Test
-  public void construct_withUnsupportedPixelWidthHeightRatio_throwsException() {
+  public void create_withUnsupportedPixelWidthHeightRatio_throwsException() {
     Context context = getApplicationContext();
 
     TransformationException exception =
         assertThrows(
             TransformationException.class,
             () ->
-                new FrameProcessorChain(
+                FrameProcessorChain.create(
                     context,
                     /* pixelWidthHeightRatio= */ 2,
                     /* inputWidth= */ 200,
@@ -121,7 +121,7 @@ public final class FrameProcessorChainTest {
     for (Size element : frameProcessorOutputSizes) {
       frameProcessors.add(new FakeFrameProcessor(element));
     }
-    return new FrameProcessorChain(
+    return FrameProcessorChain.create(
         getApplicationContext(),
         /* pixelWidthHeightRatio= */ 1,
         inputSize.getWidth(),