UMC document(audio-video-codecsdocumc-manual.pdf), "Usage Examples" part on ThreadedDemuxer includes some example code pieces.
I also attached one simple test code on threaded demuxer. It read the data from file with UMC::FIOReader.
If you want to get the bitstream from network, you need to implement you UMC::DataReader class.
Thanks,
Chao