[FFmpeg-devel] [PATCH 2/3] avfilter: add audio upsample filter

Hendrik Leppkes h.leppkes at gmail.com
Thu Apr 25 20:31:22 EEST 2019

On Thu, Apr 25, 2019 at 7:25 PM Nicolas George <george at nsup.org> wrote:
> Paul B Mahol (12019-04-25):
> > I did reacted. It plays well with negotiation.
> I missed that part, sorry. But it did not address my concern.
> > Can you be more specific what exactly you mean by "plays well with
> > sample rate negotiation"?
> If the user judges that this is the kind of sample rate change that is
> necessary, then when the negotiation detects a sample rate change is
> necessary, these filters are used.

The point of this kind of filtering is not that they are necessary to
perform filtering, because you can filter at any sample rate, but that
oversampling for certain filters, and downsampling after, improves
quality. As such, negotiation is not really equipped to handle it,
since its designed to deal with compatibility between filters, not
quality concerns, and you also wouldn't want to remove the ability to
filter at ordinary sample rates either.

- Hendrik

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