[opus] Proposal - Extended Channel Layouts in Opus

Martin Leese martin.leese at stanfordalumni.org
Thu Oct 25 17:47:49 UTC 2018

Rodger Combs wrote:

> I've run into some issues using Opus with source files in channel layouts
> other than the default 8. For instance, 2.1 isn't supported, so I have to
> either downconvert to 2.0 or upconvert to 5.1 (which usually involves adding
> empty channels, which prevents the playback device from upconverting to the
> native layout).
> To address this, I've put together an initial draft of an I-D I'd like to
> run by this list for feedback.
> Here's the RFCXML:
> And the resulting TXT:

You might like to take a look at the OggPCM
spec.  This was never implemented, and has
not been worked since 2009.  Visit:

and its companion document:

An alternative approach is to only define
popular layouts.  For more obscure layouts,
such as 2.1 and Mid/Side, assume that the
person doing the encoding knew what they
put in, and so knows what will come out.

Martin J Leese
E-mail: martin.leese  stanfordalumni.org
Web: http://members.tripod.com/martin_leese/

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