[FFmpeg-user] ffmpeg performance scaling on multicore cpus with libx264

Roger Pack rogerdpack2 at gmail.com
Mon Jun 18 19:51:03 CEST 2012

> I am using ffmpeg to convert mythtv dvb-s2 streams to matroska files, using
> libx264. Can somebody explain me the difference between specifiyng -stream 0
> and not ? Tries ffmpeg to autoscale the number of encoding threads to the
> number of cores?
> My cmdline, vmstat shows 25% idle time on Intel Q9400 quadcore:
> /usr/local/bin/ffmpeg -loglevel info -threads 0 -copyinkf -i
> /mnt/store.1/tv/3002_20120507062300.mpg -y -vcodec libx264 -vpre
> 720p25-bluray -crf 19 -c:a copy -sn -ss 145.7400 -t 1438.0600 -map 0:0 -map
> 0:2 -f matroska /mnt/store.3/convert/3002_20120507062300.mpg_1.mkv

So basically 3 cores are being used? I think the default is -threads 0
in this case..

More information about the ffmpeg-user mailing list