Create a human interface device capable of sending OSC commands:
- Functions: Play/Pause, Forward/Reverse, Tap Tempo, Next/Prev, CUE#, etc...
- Output through ethernet, wifi, or usb.
- Could be a python script to capture keystrokes, or a smartphone app, or raspberry pi/arduino/esp8266
Create a server application:
- Functions: Load video files, output RTP
- Possibly Python wrapper for gstreamer
- Stream 640x480 mp4 with sub 50ms latency
- Switch video cues and change playback speed on the fly
Everything could be running on a single computer or distributed across a LAN. For optimal streaming latency probably will need dedicated network, either router or loopback interface.