On Sat, 22 Jul 2017 at 15:14 Nicolas George <geo...@nsup.org> wrote:
> Le quartidi 4 thermidor, an CCXXV, Muhammad Faiz a écrit :
> > The behaviour is based on assumptions:
> > - copying audio data is cheap, so keeping data alignment is cheap,
> > - copying video data is not cheap, so keeping data alignment is not
> cheap,
> > e.g. crop filter.
> >
> > Should fix Ticket6349.
>
> > Note that after fc3a03fcf9cd7eafe7342e2508e6128888efa0bb, the crash has
> > been fixed.
>
> s/fixed/worked around in the most common situations/
>
> >
> > Signed-off-by: Muhammad Faiz <mfc...@gmail.com>
> > ---
> > libavutil/frame.h | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/libavutil/frame.h b/libavutil/frame.h
> > index 26261d7e40..1b08eec231 100644
> > --- a/libavutil/frame.h
> > +++ b/libavutil/frame.h
> > @@ -202,6 +202,9 @@ typedef struct AVFrame {
> > * up to 16 bytes beyond the planes, if these filters are to be
> used,
> > * then 16 extra bytes must be allocated.
> > *
>
> > + * For audio, the data should be aligned to CPUs alignment
> preference.
>
> I think this is a bad idea: it is an API change, and a rather bad one on
> top of that:
>
> - The "CPUs alignment preference" is not documented.
>
> - Requiring the application to take care of it when it could be done by
> the library is a waste of effort.
>
In practice this is not an API change because it is required for some
decoders in practice (Opus and AVX2 comes to mind).
I sent a similar patch for this 3+ years ago and nothing was done with it.
https://ffmpeg.org/pipermail/ffmpeg-devel/2014-August/160862.html
Kieran
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
