[FFmpeg-user] -crf ignored

Thomas Worth dev at rarevision.com
Thu Jun 2 01:48:53 CEST 2011


On Wed, Jun 1, 2011 at 4:33 PM, Baptiste Coudurier <
baptiste.coudurier at gmail.com> wrote:

> On 6/1/11 4:09 PM, Thomas Worth wrote:
> > On Wed, Jun 1, 2011 at 3:50 PM, Phil Rhodes <phil_rhodes at rocketmail.com
> >wrote:
> >
> >> I have historically found it very difficult to make ffmpeg obey bitrate
> >> commands - it seems to encode at the rate it thinks it wants to encode
> and
> >> woe betide you if you want anything else.
> >>
> >> Presets can be tricky becuase many windows builds don't include them, if
> >> you can get them they're very difficult to edit because they have Unix
> >> linefeeds, and in any case I don't think I've ever once got a windows
> build
> >> of ffmpeg to read a preset - no matter how hard you try, it always seems
> to
> >> complain it can't find them, even when they're colocated with the
> executable
> >> or in the current directory or whatever. This is presumably an issue of
> >> directory resolution which has failed to port cleanly but if you're not
> on a
> >> Unix-like OS then that may be a problem for you.
> >
> >
> > I don't use libx264 with FFmpeg. I use standalone x264 and just pipe from
> > FFmpeg. Most of the time, I don't need 2-pass encoding because I don't
> care
> > about hitting a particular file size so piping works for me. Plus, when
> new
> > x264 features arise, we have to wait for FFmpeg to support them with its
> > command line options. I find it easier to just pipe raw yuv420p to x264.
>
> Piping produces all sort of side-effects, I don't recommend it at all.
> Plus, the new features should be added fairly quickly.


Can you elaborate? My first thought would be a performance penalty, but does
piping differ any from simply dumping yuv420 to disk and then encoding the
raw yuv file with x264?

Now that libx264 keeps it presets to itself, I'd be willing to give
FFmpeg/libx264 another shot.


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