使用android版webrtc，如何在视频通话中保存图片？

// 创建一个实现VideoRenderer.Callbacks接口的类
private class VideoCallbacks implements VideoRenderer.Callbacks {
    @Override
    public void renderFrame(VideoRenderer.I420Frame frame) {
        // 获取视频帧数据
        byte[] data = frame.yuvPlanes[0];
        int width = frame.width;
        int height = frame.height;
        
        // 将视频帧数据转换为Bitmap
        YuvImage yuvImage = new YuvImage(data, ImageFormat.NV21, width, height, null);
        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
        yuvImage.compressToJpeg(new Rect(0, 0, width, height), 100, outputStream);
        byte[] jpegData = outputStream.toByteArray();
        Bitmap bitmap = BitmapFactory.decodeByteArray(jpegData, 0, jpegData.length);
        
        // 保存Bitmap到本地存储设备
        String fileName = "video_frame_" + System.currentTimeMillis() + ".jpg";
        File file = new File(Environment.getExternalStorageDirectory(), fileName);
        try {
            FileOutputStream outputStream = new FileOutputStream(file);
            bitmap.compress(Bitmap.CompressFormat.JPEG, 100, outputStream);
            outputStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

// 在建立视频通话连接时，设置VideoCallbacks对象作为视频渲染器的回调
VideoCallbacks videoCallbacks = new VideoCallbacks();
VideoRenderer videoRenderer = new VideoRenderer(videoCallbacks);
videoTrack.addRenderer(videoRenderer);