Resize nv12 raw data

nv12.java

public static byte[] nv12ScaleDown(byte[] bytes, int width, int height) {
  int newWidth = width >> 1;
  int newHeight = height >> 1;
  byte []result = new byte[bytes.length >> 2];

  final int sourceOffset = width * height;
  final int destOffset = newWidth * newHeight;
  for (int h = 0; h < newHeight; h++) {
    for (int w = 0; w < newWidth; w++) {
      // manipulate y
      byte sourceY = bytes[(w << 1) + h * (width << 1)];
      result[w + h * newWidth] = sourceY;
      // manipulate uv
      if ((w & 0x1) == 0 && (h & 0x1) == 0) {
          int indexSourceU = (w << 1) + h * width + sourceOffset;
          int indexSourceV = indexSourceU + 1;
          int indexDestU = w + (h >> 1) * newWidth + destOffset;
  
          result[indexDestU] = bytes[indexSourceU];
          result[indexDestU + 1] = bytes[indexSourceV];
          }
        }
    }

    return result;
}