[Vorbis] Mono encoding w/ a stereo source.

[Michael Smith]

On 11/16/05, Ian A. Underwood <agentgrn at dcne.net> wrote:
> I'm not sure since this is what I got from Lou at SpacialAudio:
>
> "We do not merge the channels for the encoding - this is all done by
> Ogg.  A simple method is usually to just add the left channel to the
> right to get the mono channel.  Although this is the correct way
> theoretically, in pratice it sounds too loud.  Thus I guess this is what
> they are doing in the Ogg encoder."

What I said was a simple fact. Libvorbis has, internally, no
capabilities to produce a mono encoding from anything other than a
mono input. Libvorbis does not do downmixing ever, under any
circumstances - there's simply no code there to do it.

So, either this person was confused, and gave you an incorrect answer,
or perhaps they're using some third-party wrapper library around
libvorbis that does the downmixing - in that latter case, they might
not be aware that the wrapper library is doing the downmixing (from
your report, apparently incorrectly), and not libvorbis.

Since we don't know anything about how they're using libvorbis, we
can't really do more than what I've said above - which is just
guessing.

Feel free to point the SpatialAudio people in my direction if they're
still confused about this.

Mike