[FFmpeg-trac] #10471(undetermined:new): FLAC in MP4 ignores WAVEFORMATEXTENSIBLE_CHANNEL_MASK Vorbis Comment

[FFmpeg]

#10471: FLAC in MP4 ignores WAVEFORMATEXTENSIBLE_CHANNEL_MASK Vorbis Comment
-------------------------------------+-------------------------------------
             Reporter:  John Regan   |                     Type:  defect
               Status:  new          |                 Priority:  normal
            Component:               |                  Version:  git-
  undetermined                       |  master
             Keywords:               |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 When an MP4 file contains FLAC audio with a channel layout that requires
 signalling via Vorbis Comment in the FLAC Specific Box - ffmpeg ignores
 the comment and uses the incorrect channel layout.

 Using the attached sample file:

 {{{
 % ffprobe 2_point_1.mp4
 ffprobe version N-111429-g9a2335444b Copyright (c) 2007-2023 the FFmpeg
 developers
   built with gcc 13.1.1 (GCC) 20230429
   configuration:
   libavutil      58. 14.100 / 58. 14.100
   libavcodec     60. 22.100 / 60. 22.100
   libavformat    60. 10.100 / 60. 10.100
   libavdevice    60.  2.101 / 60.  2.101
   libavfilter     9.  8.102 /  9.  8.102
   libswscale      7.  3.100 /  7.  3.100
   libswresample   4. 11.100 /  4. 11.100
 [mov,mp4,m4a,3gp,3g2,mj2 @ 0x55f7561ffd80] non-STREAMINFO
 FLACMetadataBlock(s) ignored
 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '2_point_1.mp4':
   Metadata:
     major_brand     : iso6
     minor_version   : 0
     compatible_brands: iso6aid3
   Duration: 00:00:06.00, start: 0.000000, bitrate: 185 kb/s
   Stream #0:0[0x1](und): Audio: flac (fLaC / 0x43614C66), 48000 Hz, 3.0,
 s16, 182 kb/s (default)
     Metadata:
       handler_name    : SoundHandler
       vendor_id       : [0][0][0][0]

 }}}

 This should list a channel layout of 2.1 and instead lists 3.0.
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/10471>
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