[FFmpeg-user] why ffmpeg takes lot of cpu?

Reindl Harald h.reindl at thelounge.net
Fri Nov 24 00:44:36 EET 2017

Am 23.11.2017 um 20:21 schrieb comp4me:
> i run this command on pc with cpu i5
> ffmpeg -i rtsp://x.x.x.x -i 2.264  -preset ultrafast -filter_complex
> "[0]crop=20:20:20:20[a];[a][1] overlay=0:0"
> i see how much this process takes me with "top" command(ubuntu)
> I see that it takes my 250% cpu
> why it takes so much cpu please?
> what can i do to reduce that?

that are just 2.5 cores - what do you expect for video encoding and on 
*what hardware* are you running?

-threads 1 would at least disable multithreading

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