Adam Adam - 8 days ago 6
Linux Question

How to stop ffmpeg remotely?

I'm running ffmpeg on another machine for screen capture. I'd like to be able to stop it recording remotely. FFMPEG requires that q is pressed to stop encoding as it has to do some finalization to finish the file cleanly. I know I could kill it with kill/killall however this can lead to corrupt videos.

Press [q] to stop encoding


I can't find anything on google specifically for this, but some there is suggestion that echoing into /proc//fd/0 will work.

I've tried this but it does not stop ffmpeg. The q is however shown in the terminal in which ffmpeg is running.

echo -n q > /proc/16837/fd/0


So how can I send a character to another existing process in such a way it is as if it were typed locally? Or is there another way of remotely stopping ffmpeg cleanly.

Answer

Newer versions of ffmpeg don't use 'q' anymore, at least on Ubuntu Oneiric, instead they say to press Ctrl+C to stop them. So with a newer version you can simply use 'killall -INT' to send them SIGINT instead of SIGTERM, and they should exit cleanly.