Remove usage of ffmpeg-kit

[jmartinesp]

Your use case

What would you like to do?

Remove all usages of the ffmpeg-kit library.

Why would you like to do it?

Currently we use ffmpeg-kit to transcode voice recording to and from ogg files with opus codec on Android versions < 10. This is a bit of an overkill, and it's also a problem for some of our customers. It should also save us a few MBs on app size.

How would you like to achieve it?

We can remove ffmpeg-kit and use libopus and libopusenc instead.

Have you considered any alternatives?

Yes, I tried several replacement libraries but in the end the simpler solution was to use the native libs for transcoding.

Additional context

No response

[bmarty]

Please double check that the license (https://github.com/xiph/libopusenc/blob/master/COPYING) is fine for our usage.

[jmartinesp]

Please double check that the license (https://github.com/xiph/libopusenc/blob/master/COPYING) is fine for our usage.

It's BSD so it shouldn't be a problem.