[Vorbis-dev] Ambisonia proposal (was Re: vorbis-tools 1.3.0 BETA - Help testing.)

[Oliver Oli]

On Thu, Sep 25, 2008 at 11:52 AM, Ivo Emanuel Gonçalves
<justivo at gmail.com> wrote:

> Now, the only thing to do is reach a consensus in how to do this.  I
> remember the top suggestions to be:
>
> 1) use Vorbis mapping 1 as opposed to default's 0

that is what the spec draft proposes. but one channel mapping type is
not enough for defining all combinations of horizontal and vertical
orders above 3rd order. for example 9 channels can be interpreted as
2/2 or 4/0 (2nd order horizonal 2nd order vertical or 4th order
horizontal without any vertical component).

> 2) use OggPCM channels

nobody has proposed any solution how this could be implemented / where
to put the needed metadata. keep in mind that most of the Ambisonics
guys (including me) are not familiar with all of the Ogg and Vorbis
specs.

> 3) do a specific Ambisonics stream with all the extra channels and let
> it be compatible with both audio formats (Vorbis and OggPCM)

could you explain this in more detail? i'm not sure what this exactly means.