sdk/android/src/java/org/webrtc/NV21Buffer.java

/*
 * 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 androidx.annotation.Nullable;
import java.nio.ByteBuffer;
import org.jni_zero.NativeMethods;

public class NV21Buffer implements VideoFrame.Buffer {
  private final byte[] data;
  private final int width;
  private final int height;
  private final RefCountDelegate refCountDelegate;

  public NV21Buffer(byte[] data, int width, int height, @Nullable Runnable releaseCallback) {
    this.data = data;
    this.width = width;
    this.height = height;
    this.refCountDelegate = new RefCountDelegate(releaseCallback);
  }

  @Override
  public int getWidth() {
    return width;
  }

  @Override
  public int getHeight() {
    return height;
  }

  @Override
  public VideoFrame.I420Buffer toI420() {
    // Cropping converts the frame to I420. Just crop and scale to the whole image.
    return (VideoFrame.I420Buffer) cropAndScale(0 /* cropX */, 0 /* cropY */, width /* cropWidth */,
        height /* cropHeight */, width /* scaleWidth */, height /* scaleHeight */);
  }

  @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) {
    JavaI420Buffer newBuffer = JavaI420Buffer.allocate(scaleWidth, scaleHeight);
    NV21BufferJni.get()
        .cropAndScale(
            cropX,
            cropY,
            cropWidth,
            cropHeight,
            scaleWidth,
            scaleHeight,
            data,
            width,
            height,
            newBuffer.getDataY(),
            newBuffer.getStrideY(),
            newBuffer.getDataU(),
            newBuffer.getStrideU(),
            newBuffer.getDataV(),
            newBuffer.getStrideV());
    return newBuffer;
  }

  @NativeMethods
  interface Natives {
    void cropAndScale(
        int cropX,
        int cropY,
        int cropWidth,
        int cropHeight,
        int scaleWidth,
        int scaleHeight,
        byte[] src,
        int srcWidth,
        int srcHeight,
        ByteBuffer dstY,
        int dstStrideY,
        ByteBuffer dstU,
        int dstStrideU,
        ByteBuffer dstV,
        int dstStrideV);
  }
}