Starting multiple ffmpeg instances

New to linux and having problems.

I am trying to setup a system that will allow me to start multiple ffmpegs to convert live TV so I can archive certain programs. The source is a few TV cards which means I can encode multiple s开发者_如何学Gotreams at the same time. The PC is an i7 8 core.

I have tried to write a program that uses threads to start multiple ffmpegs and capture all the ffmpeg messages so I can watch the time elapsed, and when this hits a predetermined time stops the task and ffmpeg and then waits for the next scheduled recording, but I'm stuck on the capture of the ffmpeg output.

See popen function.