[FFmpeg-devel] [PATCH][WIP] lavfi/aconvert: use libswresample.

[Clément Bœsch]

On Fri, Jan 27, 2012 at 12:51:35PM +0100, Stefano Sabatini wrote:
> On date Thursday 2012-01-26 17:24:49 +0100, Clément Bœsch encoded:
> > On Thu, Jan 26, 2012 at 04:05:32PM +0100, Nicolas George wrote:
> > > Le septidi 7 pluviôse, an CCXX, Clément Bœsch a écrit :
> > > > BTW, what is planned for the audio packing in lavfi?
> > > 
> > > I think I do not understand what you mean here.
> > > 
> > 
> > As you mentioned later, lavfi has a bit flag to indicates if it is
> > processing a planar or packed format. It was done like this before the
> > planar formats got introduced.
> > 
> 
> > Now the information is "embedded" in the sample format and we don't need
> > that bit anymore, so that attribute could be dropped. It would also
> > simplifies of this filter by dropping the last parameter (you use "s16" if
> > you want packed signed 16-bit samples, and "s16p" if you want planar
> > signed 16-bit samples).
> 
> After quick thought I think the better thing is to drop the
> packed/planar attribute at all, and gain consistency with lavu and
> with the video path (for which "packing" information is stored in the
> pix_fmt).
> 

I also think it's better (I know I'm biased because it would
solve/simplify my issue), but I'm not motivated to remove it from lavfi
myself…

> Note that there is an intrinsic difference between pixfmt and
> samplefmt, pixfmt encodes both the information related to the type of
> content and to the layout, samplefmt contains the information related
> to the type of samples and to the packing, but not to the layout.
> 

I can't say for the video, but concerning audio I think it's a good thing
to have a distinction here. :)

> > Still, dropping the packing format flag has various implications:
> 
> >  - we won't have a way of specifying "auto" for the planar/packed if we
> >    don't "auto" the sample format
> 
> yes, thus should not be a big issue (unless someone can provide a
> meaningful use case), also we can provide facilities for generating
> a list of packed/planar and provide means and syntax for filtering a
> specific type of sample_fmt.
> 

OK good, the patch will be updated to drop that feature then.

[...]

-- 
Clément B.
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