In case anyone ever has the same question, use ptty for this. I found this post amazingly helpful:

http://stackoverflow.com/questions/1168 ... -dup2-in-c

I think I need to do something with pipes here but I am not familiar with the process. I'm looking for a way to send signals or key presses to a process (specifically omxplayer) and I can't piece it all together. The "TODO" comments below show what I am trying to accomplish. Video playback works. I ...