I use Auvedia B101 bridge on Raspberry Pi 3B+. Need to muxing audio and video into container for streaming in VLC and then parse(catch) all the packets for testing.
Edit: there is a HDMI source which connects to my Pi through the B101 bidge. I can receive video/audio signals on the Pi board. Just need to configure gstreamer or ffmpeg to mux audio/video together for streaming, and then parse the packets in bits (some lines of C coding needed). Because it is expected to be done in few days, I can top-up more if the time requirement is met.