android camera2 image 中獲得的yuv數據的格式轉換

/**
 * 圖片格式轉換
 */
private final int colorFormatI420 = 1;
private final int colorFormatNV21 = 2;

private byte[] data = new byte[0];
private byte[] rowData = new byte[0];


private byte[] getDataFromImage(Image image, int colorFormat) {

    Rect crop = image.getCropRect();
    int format = image.getFormat();
    int width = crop.width();
    int height = crop.height();
    Image.Plane[] planes = image.getPlanes();
    if (data.length == 0) {
        data = new byte[width * height * ImageFormat.getBitsPerPixel(format) / 8];
    }
    if (rowData.length == 0) {
        rowData = new byte[planes[0].getRowStride()];
    }

    int channelOffset = 0;
    int outputStride = 1;
    for (int i = 0; i < planes.length; i++) {
        switch (i) {
            case 0:
                channelOffset = 0;
                outputStride = 1;
                break;
            case 1:
                if (colorFormat == colorFormatI420) {
                    channelOffset = width * height;
                    outputStride = 1;
                } else if (colorFormat == colorFormatNV21) {
                    channelOffset = width * height + 1;
                    outputStride = 2;
                }
                break;
            case 2:
                if (colorFormat == colorFormatI420) {
                    channelOffset = (int) (width * height * 1.25);
                    outputStride = 1;
                } else if (colorFormat == colorFormatNV21) {
                    channelOffset = width * height;
                    outputStride = 2;
                }
                break;
            default:
        }
        ByteBuffer buffer = planes[i].getBuffer();
        int rowStride = planes[i].getRowStride();
        int pixelStride = planes[i].getPixelStride();

        int shift = (i == 0) ? 0 : 1;
        int w = width >> shift;
        int h = height >> shift;
        buffer.position(rowStride * (crop.top >> shift) + pixelStride * (crop.left >> shift));
        for (int row = 0; row < h; row++) {
            int length;
            if (pixelStride == 1 && outputStride == 1) {
                length = w;
                buffer.get(data, channelOffset, length);
                channelOffset += length;
            } else {
                length = (w - 1) * pixelStride + 1;
                buffer.get(rowData, 0, length);
                for (int col = 0; col < w; col++) {
                    data[channelOffset] = rowData[col * pixelStride];
                    channelOffset += outputStride;
                }
            }
            if (row < h - 1) {
                buffer.position(buffer.position() + rowStride - length);
            }
        }
    }

    return data;
}

byte[] frameData;
ByteBuffer bufferY;
ByteBuffer bufferV;

/**
 * 圖片格式yuv轉換nv21
 */
private void yuvConvert(Image image) {

    bufferY = image.getPlanes()[0].getBuffer();
    bufferV = image.getPlanes()[2].getBuffer();
    byte[] y = new byte[bufferY.remaining()];
    byte[] v = new byte[bufferV.remaining()];
    bufferY.get(y, 0, bufferY.remaining());
    bufferV.get(v, 0, bufferV.remaining());
    frameData = byteMerger(y, v);
}