Android YuvConverter: Use OpenGL Framebuffer instead of EGL pixel buffer

webrtc/api/android/java/src/org/webrtc/SurfaceTextureHelper.java

 /*
  *  Copyright 2015 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 116 matching lines @@
     surfaceTexture = new SurfaceTexture(oesTextureId);
     surfaceTexture.setOnFrameAvailableListener(new SurfaceTexture.OnFrameAvailableListener() {
       @Override
       public void onFrameAvailable(SurfaceTexture surfaceTexture) {
         hasPendingTexture = true;
         tryDeliverTextureFrame();
       }
     });
   }
 
-  private YuvConverter getYuvConverter() {
-    // yuvConverter is assigned once
-    if (yuvConverter != null)
-      return yuvConverter;
-
-    synchronized (this) {
-      if (yuvConverter == null)
-        yuvConverter = new YuvConverter(eglBase.getEglBaseContext());
-      return yuvConverter;
-    }
-  }
-
   /**
    * Start to stream textures to the given |listener|. If you need to change listener, you need to
    * call stopListening() first.
    */
   public void startListening(final OnTextureFrameAvailableListener listener) {
     if (this.listener != null || this.pendingListener != null) {
       throw new IllegalStateException("SurfaceTextureHelper listener has already been set.");
     }
     this.pendingListener = listener;
     handler.post(setListenerRunnable);
@@ skipping 65 matching lines @@
       @Override
       public void run() {
         isQuitting = true;
         if (!isTextureInUse) {
           release();
         }
       }
     });
   }
 
-  public void textureToYUV(
-      ByteBuffer buf, int width, int height, int stride, int textureId, float[] transformMatrix) {
-    if (textureId != oesTextureId)
+  public void textureToYUV(final ByteBuffer buf, final int width, final int height,
+      final int stride, final int textureId, final float[] transformMatrix) {
+    if (textureId != oesTextureId) {
       throw new IllegalStateException("textureToByteBuffer called with unexpected textureId");
+    }
 
-    getYuvConverter().convert(buf, width, height, stride, textureId, transformMatrix);
+    ThreadUtils.invokeAtFrontUninterruptibly(handler, new Runnable() {
+      @Override
+      public void run() {
+        if (yuvConverter == null) {
+          yuvConverter = new YuvConverter();
+        }
+        yuvConverter.convert(buf, width, height, stride, textureId, transformMatrix);
+      }
+    });
   }
 
   private void updateTexImage() {
     // SurfaceTexture.updateTexImage apparently can compete and deadlock with eglSwapBuffers,
     // as observed on Nexus 5. Therefore, synchronize it with the EGL functions.
     // See https://bugs.chromium.org/p/webrtc/issues/detail?id=5702 for more info.
     synchronized (EglBase.lock) {
       surfaceTexture.updateTexImage();
     }
   }
@@ skipping 18 matching lines @@
     listener.onTextureFrameAvailable(oesTextureId, transformMatrix, timestampNs);
   }
 
   private void release() {
     if (handler.getLooper().getThread() != Thread.currentThread()) {
       throw new IllegalStateException("Wrong thread.");
     }
     if (isTextureInUse || !isQuitting) {
       throw new IllegalStateException("Unexpected release.");
     }
-    synchronized (this) {
-      if (yuvConverter != null)
-        yuvConverter.release();
+    if (yuvConverter != null) {
+      yuvConverter.release();
     }
     GLES20.glDeleteTextures(1, new int[] {oesTextureId}, 0);
     surfaceTexture.release();
     eglBase.release();
     handler.getLooper().quit();
   }
 }