[opus] Proposal - Extended Channel Layouts in Opus

Martin Leese martin.leese at stanfordalumni.org
Fri Oct 26 04:19:03 UTC 2018

On 10/25/18, Rodger Combs wrote:
>> On Oct 25, 2018, at 12:47, Martin Leese <martin.leese at stanfordalumni.org>
>> wrote:
>> 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.
> I'm not sure what you mean here. There are a few ways to push some encoder
> API work onto the user (or API consumer), but there has to be some way to
> communicate the layout in-stream to the decoder, or else (as is currently
> the case) we'd be forcing anyone encoding less-than-universal layouts to
> pass that information out-of-band to anyone wanting to decode the stream.

Yes, passing the details of obscure layouts
out-of-band is exactly what I meant,
particularly as the person decoding the file is
probably also the person who encoded it.  As
you will have seen in the OggPCM spec, there
are an awful lot of possible layouts.  2.1 is not
a *consumer* format, so the need to create a
standard for it is not great.

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

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