如何在Android的Camera 2 API中以YUV格式获取字节流？

Question

如何获取Surface上渲染内容的字节流？我能够得到连续帧数和它的属性。我需要将字节流传递给我的库函数。

CameraCaptureSession.StateCallback cameraCaptureSessionStateCallback = new CameraCaptureSession.StateCallback() {
    @Override
    public void onConfigured(CameraCaptureSession session) {
        try {
            session.setRepeatingRequest(mRequestBuilder.build(), cameraCaptureSessionCallback, new Handler());
        } catch (CameraAccessException e) {
            Log.e("Camera Exception", e.getMessage());
        }
    }

    @Override
    public void onConfigureFailed(CameraCaptureSession session) {

    }
};

 private CameraCaptureSession.CaptureCallback cameraCaptureSessionCallback = new CameraCaptureSession.CaptureCallback() {
        @Override
        public void onCaptureStarted(CameraCaptureSession session, CaptureRequest request, long timestamp, long frameNumber) {
            super.onCaptureStarted(session, request, timestamp, frameNumber);
            Log.d("FRAME",String.valueOf(timestamp)+" "+String.valueOf(frameNumber));
        }

        @Override
        public void onCaptureCompleted(CameraCaptureSession session, CaptureRequest request, TotalCaptureResult result) {
            super.onCaptureCompleted(session, request, result);
            Integer iso = result.get(CaptureResult.SENSOR_SENSITIVITY);
            long timeExposure = result.get(CaptureResult.SENSOR_EXPOSURE_TIME);
            Log.d("FRAME",String.valueOf("ISO :"+iso)+" "+String.valueOf("EXPOSURE :"+timeExposure));

            //byte [] yuvBytes = 
            faceRate.StoreFaceRating(yuvBytes, mSizes[2].getWidth(), mSizes[2].getHeight(), 270);

        }

        @Override
        public void onCaptureFailed(CameraCaptureSession session, CaptureRequest request, CaptureFailure failure) {
            super.onCaptureFailed(session, request, failure);
        }
    };