[flac-dev] Define 6.1 and 7.1 channel mappings

Stephen F. Booth
2012-09-21T23:31:21Z

I like the idea of standardizing the channel maps.  I would suggest the
following channel orderings:

6.1:  L R C LFE Ls Rs Cs (MPEG 6.1 A layout)
7.1:  L R C LFE Ls Rs Rls Rrs (MPEG 7.1 B  layout)

I think this more closely matches what Apple has done and what the default WAVE
channel order is
(http://msdn.microsoft.com/en-us/windows/hardware/gg463006.aspx).

Stephen


On Friday, September 21, 2012 at 5:22 PM, Ralph Giles wrote:

> The FLAC format specification never defined the semantics of 7- and
> 8-channel files, which has caused some pain for some years now.
>
> Attached is a patch to define them. I don't know if this follows
> "follows SMPTE/ITU-R recommendations," but it follows common tool
> practice. I chose the set of surround speaker designations used by home
> theatre systems, which is the same set used by the Vorbis and Opus
mappings.
>
> The ordering follows the WAVE file format, rather than the Vorbis order
> of other Xiph codecs. This matches what flac has done for the existing
> mappings, and it allegedly what current tools like libavformat are doing.
>
> Please consider applying this patch to have a definitive statement on
> the channel map for implementors to follow.
>
> -r
>
> P.S. This doesn't update the flac command-line tool to enforce this
> mapping. That needs to be done as well, along with test files.
>
> _______________________________________________
> flac-dev mailing list
> flac-dev at xiph.org (mailto:flac-dev at xiph.org)
> http://lists.xiph.org/mailman/listinfo/flac-dev
>
>
>
>
> Attachments:
> - channel-mapping.patch
>


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