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

[Paul B Mahol]

On 5/12/19, Nicolas George <george at nsup.org> wrote:
> Paul B Mahol (12019-05-12):
>> Calling atempo filter atempo when it also modifies pitch is bad for users
>> and
>> at same time not having apitch filter, user would think that they can
>> not alter pitch.
>> Sorry if you can not understand my fears.
>
> As I have pointed to you (but you made a show of misunderstanding on
> purpose), changing the pitch and changing the speed of an audio signal
> are fundamentally the same thing, they are connected by the sample rate.
>
> In my experience, most people are aware of that, including completely
> non-technical people: they know that if you speed up or down a sound,
> its pitch changes.
>
> The documentation, of course, can be enhanced to make sure it contains
> all keyword a user is likely to search. And if the options can be
> tweaked to allow setting exactly the wanted output in the most
> convenient way (like we have a setdar, even though only the SAR exists
> in the library), it is even better.

We have both setsar and setdar, why should we not have both atempo and apitch?