[Vorbis] Mono encoding w/ a stereo source.

[Michael Smith]

On 11/16/05, Ian A. Underwood <agentgrn at dcne.net> wrote:
> Crew,
>
> I've run into something a little odd with the vorbis encoder and would
> like some input.
>
> I use SpacialAudio's SAM3 Broadcaster and am having problems with the
> ogg encoder when I create a mono output stream.  It seems as if the
> signal level of the left and right sides are being combined before the
> encoding process, leaving the sound muddy and overdriven.  As such, if I
> reduce the output level by 6db, the combined streams are at the right
> level.  The settings I'm using are Quality -1, 32kbps/44kHz.
>
> SpacialAudio suggested that they are passing the audio info to the
> library as required.

If you're encoding in mono, then the data being passed to the encoder
library is in mono - libvorbis does not do downmixing internally. It
sounds, from your description, like SAM3 is internally doing
downmixing to mono, but in a way that produces poor quality audio. Is
that possible?

Mike