Android: Generalize and make TextureBufferImpl public

This CL generalizes TextureBufferImpl so it's useful from other contexts than
from a SurfaceTextureHelper, and fixes a bug in cropAndScale(). It also exposes
the class in the api so that clients don't have to duplicate the logic.

Bug: None
Change-Id: Ib82aa8bee025ec14de74a7be9d91fd4e5298a248
Reviewed-on: https://webrtc-review.googlesource.com/69819
Reviewed-by: Sami Kalliomäki <sakal@webrtc.org>
Commit-Queue: Magnus Jedvert <magjed@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22875}

sdk/android/api/org/webrtc/TextureBufferImpl.java

@@ -0,0 +1,95 @@
+/*
+ *  Copyright 2017 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.
+ */
+
+package org.webrtc;
+
+import android.graphics.Matrix;
+import javax.annotation.Nullable;
+import android.os.Handler;
+
+/**
+ * Android texture buffer that glues together the necessary information together with a generic
+ * release callback. ToI420() is implemented by providing a Handler and a YuvConverter.
+ */
+public class TextureBufferImpl implements VideoFrame.TextureBuffer {
+  private final int width;
+  private final int height;
+  private final Type type;
+  private final int id;
+  private final Matrix transformMatrix;
+  private final Handler toI420Handler;
+  private final YuvConverter yuvConverter;
+  private final RefCountDelegate refCountDelegate;
+
+  public TextureBufferImpl(int width, int height, Type type, int id, Matrix transformMatrix,
+      Handler toI420Handler, YuvConverter yuvConverter, @Nullable Runnable releaseCallback) {
+    this.width = width;
+    this.height = height;
+    this.type = type;
+    this.id = id;
+    this.transformMatrix = transformMatrix;
+    this.toI420Handler = toI420Handler;
+    this.yuvConverter = yuvConverter;
+    this.refCountDelegate = new RefCountDelegate(releaseCallback);
+  }
+
+  @Override
+  public VideoFrame.TextureBuffer.Type getType() {
+    return type;
+  }
+
+  @Override
+  public int getTextureId() {
+    return id;
+  }
+
+  @Override
+  public Matrix getTransformMatrix() {
+    return transformMatrix;
+  }
+
+  @Override
+  public int getWidth() {
+    return width;
+  }
+
+  @Override
+  public int getHeight() {
+    return height;
+  }
+
+  @Override
+  public VideoFrame.I420Buffer toI420() {
+    return ThreadUtils.invokeAtFrontUninterruptibly(
+        toI420Handler, () -> yuvConverter.convert(this));
+  }
+
+  @Override
+  public void retain() {
+    refCountDelegate.retain();
+  }
+
+  @Override
+  public void release() {
+    refCountDelegate.release();
+  }
+
+  @Override
+  public VideoFrame.Buffer cropAndScale(
+      int cropX, int cropY, int cropWidth, int cropHeight, int scaleWidth, int scaleHeight) {
+    final Matrix newMatrix = new Matrix(transformMatrix);
+    newMatrix.preTranslate(cropX / (float) width, cropY / (float) height);
+    newMatrix.preScale(cropWidth / (float) width, cropHeight / (float) height);
+
+    retain();
+    return new TextureBufferImpl(
+        scaleWidth, scaleHeight, type, id, newMatrix, toI420Handler, yuvConverter, this ::release);
+  }
+}