[opus] [PATCH] Add Functions to Create Ambisonic Multistream Encoder

[Michael Graczyk]

Jean-Marc,

> Is there any reason you can't just use the generic multi-stream API,
> i.e. opus_multistream_encoder_init() and give it the mapping you need?

I would like the encoder to make decisions based on the fact that the
audio is Ambisonics. For example, the bitrate allocation should not be
the same for every channel. The original multistream API does not
provide a way to pass in mapping family so I don't know how we could
signal "ambisonics" to the

> If it turns out you need this kind of thing too, then yes we
> would probably just want to extend the
> opus_multistream_surround_encoder_*() calls since they already take a
> family argument.

Alright, that is simpler. I can modify the patch to simply add
"mapping_family == 2" to the allowed values in the surround encoder
functions.