Record video using video core library

Question

would anybody please tell me how to record a video as I live stream it to wows server using video core library..?

I researched a lot. But could not find a solution. Can I record video by uncommenting this section in VCSimpleSession.mm ? But How..? Any help is much appreciated. Thank you.

    /*m_muxer = std::make_shared<videocore::Apple::MP4Multiplexer>();
        videocore::Apple::MP4SessionParameters_t parms(0.) ;
        std::string file = [[[self applicationDocumentsDirectory] stringByAppendingString:@"/output.mp4"] UTF8String];
        parms.setData(file, self.fps, self.videoSize.width, self.videoSize.height);
        m_muxer->setSessionParameters(parms);
        m_aacSplit->setOutput(m_muxer);
        m_h264Split->setOutput(m_muxer);*/