Utils::captureScreen is not working when i use VideoPlayer

I try to capture screen while video playing but its not working for me, Please help me about it?
Also try to capture screen from android but it shows black screen only. In my app, video play on screen and camera preview on specific part of screen. I want to capture this view but fail to achieve please help about it.

utils::captureScreen( CC_CALLBACK_2(ClassVideo::afterCaptured, this), "sdcard/screenshot_captu.png");