Hi.
I just noticed that oggdec channel reordering for WAV is bogus.
With irrelevant clutter removed, oggenc has the following code:
permute = {0,2,1,4,5,3} // oggenc/audio.c:401
for (j)
to_vorbis[j] = from_wav[permute[j]] // oggenc/audio.c:619
While oggdec has the following code:
permute = {0,2,1,5,3,4} // oggdec/oggdec.c:229
for (j)
to_wav[permute[j]] = from_vorbis[j] // oggdec/oggdec.c:240
You can notice the permutation vectors are reciprocal to each other and that
the code apply them in the opposite direction. Both inversions cancel
each-other.
After more careful checking with the specs, oggenc is right and oggdec is
wrong.
Note that this is for 5.1; 5.0 seems even wronger and 6.1 and 7.1 are not
implemented.
The obvious fix is to copy-paste the matrix from oggenc to oggdec. Patch
attached.
Regards,
--
Nicolas George
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0001-oggdec-import-permute-matrix-from-oggenc.patch
Type: text/x-diff
Size: 1550 bytes
Desc: not available
Url :
http://lists.xiph.org/pipermail/vorbis-dev/attachments/20120704/8c9cbef0/attachment.patch
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 198 bytes
Desc: Digital signature
Url :
http://lists.xiph.org/pipermail/vorbis-dev/attachments/20120704/8c9cbef0/attachment.pgp
