[Vorbis-dev] Big issue regarding channel order mapping in 5.1 has been reported

[Ivo Gonçalves]

I know there's a bug tracker, and that is exactly the reason why I am 
posting this on the dev list. There has been a report from one of the foobar 
developers regarding oggenc on the HA forums, but he later posted it at the 
bug tracker as well. Three weeks have passed and no one seems to have 
noticed it was there.

~*~

URL: http://trac.xiph.org/cgi-bin/trac.cgi/ticket/736
Subject: incorrect 5.1 channel order handling in oggenc/oggdec
Message: Oggenc appears not to remap 5.1 channel order from WAV order 
(L/R/C/LFE/BL/BR) to Vorbis order defined by xiph's specifications :

six channels : the stream is 5.1 surround. channel order: front left, front 
center, front right, rear left, rear right, LFE

Tested with rarewares build 2005-07-10.

The same problem applies to oggdec (again assumes WAV channel order on 
libvorbis output, so it actually decodes incorrect oggenc output back to 
correct WAV).

~*~

There's also the discussion on HA, at [ 
http://www.hydrogenaudio.org/forums/index.php?showtopic=38618 ]. I believe 
that john33 from rarewares seems to be attempting to fix the issue on 
OggDropXPd according his post today in the thread.

OK, it's bad already that Vorbis can't handle 5.1 well--if at all--but it's 
even worse when it gets the channel order wrong from the standard.

I decided to bring the attention on this issue to the dev list because of 
this single post on the HA forums: "No, thank you. If they need third party 
contributors to fix trivial bugs in reference encoder/decoder, their project 
is short-lived anyway."

This made me kinda sad considering it's almost true these days, especially 
with Monty away doing whatever he is doing that isn't Ogg and Vorbis 
development. Please do not get mad at me for attempting to get everyone's 
attention on this.

--Ivo Gonçalves

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