[FFmpeg-user] Audio/Video slowly desync while using ffmpeg's x11grab

Carl Eugen Hoyos cehoyos at ag.or.at
Sun Feb 10 10:47:22 CET 2013

Kody Kurtz <kody.j.kurtz <at> gmail.com> writes:

> My CPU usage while recording is 50%, and that's
> accounting for both CPU usage from the game itself 
> and CPU usage from capturing the video and audio, 
> so I doubt that could be the cause, either.

Single-core cpu?

In any case, test -r 10

> The command I use to capture is
> ffmpeg -f alsa -ac 2 -i pulse -f x11grab -r 30 
> -s 640x480 -i :0.0+256,256 -acodec pcm_s16le 
> -vcodec libx264 -crf 0 -preset ultrafast 
> -threads 0 -y Capture.mkv

(If your cpu really is single-core, I would expect 
-threads 1 to perform better.)

Complete, uncut console output missing.

Carl Eugen

More information about the ffmpeg-user mailing list