[FFmpeg-devel] [PATCH] avfilter: add apitch filter

[Michael Niedermayer]

On Wed, May 15, 2019 at 07:19:43PM +0200, Paul B Mahol wrote:
> On 5/12/19, Paul B Mahol <onemda at gmail.com> wrote:
> > On 5/12/19, Michael Niedermayer <michael at niedermayer.cc> wrote:
> >> On Sun, May 12, 2019 at 11:00:51PM +0200, Nicolas George wrote:
> >>> Marton Balint (12019-05-12):
> >>> > Yeah, you are right, what I had in mind was this:
> >>> >
> >>> > apitch  ===  asetrate,aresample,atempo
> >>>
> >>> Exactly. And reciprocally, atempo = apitch+asetrate+aresample.
> >>>
> >>> Furthermore, since it works with the spectrum, the filter that does the
> >>> hard work can probably easily output at any sample rate, at a cost much
> >>> lower than resampling afterwards. Therefore, it makes most sense to have
> >>> a single filter with all three parameters (sample rate, speed adjustment
> >>> and pitch adjustment).
> >>
> >> and if thats done in our resampler than that can also be combined with
> >> changing the channel order, layout, sample type and so on.
> >> Iam not sure its a good idea but purely technically it should be more
> >> efficient to do it all together.
> >> Also swresample already supports an external FFT resampler so it might
> >> actually fit in there nicely and it might even allow us to remove an
> >> external
> >> dependancy without loosing a feature. (assuming the new FFT resampler
> >> would be equally good)
> >>
> >>
> >
> > To make it work dynamically, filter must resample audio internally.
> >
> 
> Can I get testers?

Iam not sure what you ask for exactly (which is why i didnt reply sooner)
but if theres a patch for an implementation in swr then sure as the maintainer
of swr i will test it. But iam not sure thats what you had in mind ...

Thanks

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

When you are offended at any man's fault, turn to yourself and study your
own failings. Then you will forget your anger. -- Epictetus
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