[FFmpeg-user] improving performances- general questions
lou at lrcd.com
Fri Aug 17 00:49:34 CEST 2012
On Thu, 16 Aug 2012 19:10:40 -0300
Rossana Guerra <guerra.rossana at gmail.com> wrote:
> ok, thanks I'll take note.
> about graphic card? it would hep?
Also note that top-posting is not recommended on this mailing list.
> 2012/8/16 Roger Pack <rogerdpack2 at gmail.com>
> > > Actually the console command is quite simple, and the output it is quite
> > > straightforward
> > >
> > > Command line:
> > >
> > > ffmpeg -loglevel error -i video1.avi -vf "movie=logo.png [logo];
> > [in][logo]
> > > overlay=W-w-10:10:1[out]" -vcodec libx264 -acodec libmp3lame -b 1400k
> > -b:a
> > > 192k outlogov1.avi
Why AVI and not MP4 or MKV? AVI is generally not recommended with H.264.
> > and your output?
> > ...
> > >
> > > Sum it up:
> > > - a good processor?
> > > - RAM requirements? 2gb more?
> > RAM won't help I doubt (as long as it's using 100% cpu...ffmpeg tends
> > to not use too much RAM).
> > Since you're using libx264 you could use
> > -preset ultrafast (makes the files larger, but faster encoding)
> > or use mpeg4 for the video codec if that's an option.
Current x264 presets in descending order of speed are: ultrafast,
superfast, veryfast, faster, fast, medium, slow, slower, veryslow,
placebo. Ignore placebo as it is a joke and a waste of time. Typical
recommendation is to use the slowest preset you have patience for. If
it is too slow use a faster preset.
You asked about threads earlier but it was cut in a previous reply.
Recent ffmpeg uses "-threads 0" with libx264 by default, IIRC, so you
don't need to mess with that option. The value of "0" confuses some
people, but to simplify consider it to be "auto" and not "no threads".
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