[FFmpeg-devel] [PATCH] 8 channel layout fix for Vorbis decoder

Michael Niedermayer michaelni
Sat Nov 7 14:17:17 CET 2009

On Tue, Nov 03, 2009 at 07:39:51PM -0500, Jason Tackaberry wrote:
> Hi,
> The attached patch implements sane channel layout behaviour for 7 and 8
> channel Vorbis files.
> The Vorbis specification [1] says that the layout for greater than six
> channels is left up to the application.  I think the most sensible and
> consistent layout for 7 and 8 channels is their 5 and 6 channel
> counterparts with back left/right channels appended.

ahh, xiph-alzheimer design again
from all options they succeed in selecting the one that is most different
from everyone else no matter how broken the option is even on its own

so what are our options
1. leave channels as they are ordered
   -> requires each application to have a special case for vorbis because
      this order is never what one expects
2. do a best effort reordering 
   -> someone will complain that its not correct for his file (that he just
      and his application could magically do better if only the evil
      ffmpeg didnt reorder channels

add a value to request_channel_layout that specifies raw channel order and
layout without any changes and then do the reorder as you do in your patch
if this is not requested.
comments? suggestions? flames?

Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Many that live deserve death. And some that die deserve life. Can you give
it to them? Then do not be too eager to deal out death in judgement. For
even the very wise cannot see all ends. -- Gandalf
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