[gstreamer-bugs] [Bug 448861] New: Problems with multichannel AAC -> Vorbis transcoding

[GStreamer (bugzilla.gnome.org)]

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  GStreamer | don't know | Ver: HEAD CVS
           Summary: Problems with multichannel AAC -> Vorbis transcoding
           Product: GStreamer
           Version: HEAD CVS
          Platform: Other
        OS/Version: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: Normal
         Component: don't know
        AssignedTo: gstreamer-bugs at lists.sourceforge.net
        ReportedBy: tristan.brindle at gmail.com
         QAContact: gstreamer-bugs at lists.sourceforge.net
     GNOME version: Unspecified
   GNOME milestone: Unspecified


The file 

http://images.apple.com/movies/fox/fantastic_4-silver_surfer/fantastic4silversurfer-tlr1_h720p.mov

contains, according to Totem, a 7.1-channel AAC track (although VLC says it's
6-channel). Attempting to transcode the audio to Vorbis with the standard
pipeline:

gst-launch-0.10 filesrc location=1.mov ! decodebin ! queue ! audioconvert !
vorbisenc ! oggmux ! filesink location=2.ogg

generates a mono Vorbis stream rather than the multichannel one would expect.

Forcing the caps to "audio/x-raw-float, channels=5" (for example) in between
audioconvert and vorbisenc will generate a multichannel vorbis file, but the
channel mapping seems to be incorrect (centre audio seems to come through the
right speaker, for example).

I'm not sure whether this is a bug in faad, audioconvert or vorbisenc, so I'm
leaving it as "don't know".

If you need any more info, please let me know


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