[opus] Stereo channel separation

[Jean-Marc Valin]

On 11/20/2013 03:37 PM, O'Connor, Kevin wrote:
> I have an application I intend to use Opus for that involves creating
> recordings of two-party conversations where each party is saved as a
> separate channel. Audio may be later processed or analyzed on a
> per-party basis so if audio in one channel affects the other channel, it
> could create problems. My question is, if I use a single stereo Opus
> stream, how well will channel separation be maintained? Are there any
> other disadvantages to doing it this way?

If you encode as stereo, you should still have perfect channel
separation. However, the encoding will likely be less efficient than
having two separate streams. How much is not clear -- you'll have to
experiment.

> I would prefer to use a stereo stream. Apart from the better space
> efficiency, decoding applications that need a single mixed stream will
> get a mono mixed stream from the decoder, if they choose, instead of
> having to mix it themselves.

You could also have a look at "multi-stream" files, which are typically
used for surround, but also let you pack two mono streams in a single
Ogg file.

Cheers,

	Jean-Marc