[FFmpeg-devel] [PATCH 3/6] lavc: deprecate -ab as part of FF_API_OLD_AVOPTIONS.

[Michael Niedermayer]

On Fri, Aug 28, 2015 at 03:02:47PM -0400, Ronald S. Bultje wrote:
> Hi,
> 
> On Mon, Aug 17, 2015 at 9:56 PM, Michael Niedermayer <michael at niedermayer.cc
> > wrote:
> 
> > On Mon, Aug 17, 2015 at 01:38:19PM -0400, Ronald S. Bultje wrote:
> > > Hi,
> > >
> > > On Mon, Aug 17, 2015 at 1:12 PM, Michael Niedermayer
> > <michael at niedermayer.cc
> > > > wrote:
> > >
> > > > On Mon, Aug 17, 2015 at 11:52:16AM -0400, Ronald S. Bultje wrote:
> > > > > ---
> > > > >  libavcodec/options_table.h | 2 ++
> > > > >  1 file changed, 2 insertions(+)
> > > >
> > > > googling for
> > > > ffmpeg "-ab"
> > > > has 332.000 matches
> > > >
> > > > ffmpeg "-b:a"
> > > > has 64.100 matches
> > > >
> > > > this patch is simply a bad idea
> > >
> > >
> > > So, there's a few practical problems here. A) if we remove flag/mask from
> > > the set_defaults calls (other patch in this set), the audio is also used
> > > for the video ones (since we ignore media type), and thus we use (after
> > > FF_API_OLD_AVOPTIONS is 0) the audio bitrate as default for video also.
> > > That's bad, and causes some fate failures. We can workaround that by
> > > inverting the ordering of these two, but then, the general one _always_
> > > (even before FF_API_OLD_AVOPTIONS=0) takes precedence over the audio one,
> > > so all fate results without explicit bitrate change from ab=128k to
> > > ab=200k. (I'm working around that by making each fate test set bitrate
> > > explicit where relevant.)
> > >
> >
> > > Alternate suggestion: I don't mind if -ab gets a workaround in ffmpeg.c,
> > > but I'd like to remove it from the libav* code.
> >
> > ffserver seems to have "ab" hardcoded in
> > ffserver_config.c
> > this will need some change too, i dont know the code so i dont know
> > what needs to be done / if a simple change to "b" is sufficient
> > it seems to work with "b" better than with "ab" though after
> > FF_API_OLD_AVOPTIONS=0)
> 
> 
> This is done now, so are you now OK with this?

if people want to remove it and it doesnt break anything, yes

ill add a workaround to ffmpeg.c so this doesnt break command
lines which depend on the default audio bitrate


[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Into a blind darkness they enter who follow after the Ignorance,
they as if into a greater darkness enter who devote themselves
to the Knowledge alone. -- Isha Upanishad
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