[FFmpeg-trac] #9763(avformat:new): ipcm little endian misidentified as big endian

[FFmpeg]

#9763: ipcm little endian misidentified as big endian
-------------------------------------+-------------------------------------
             Reporter:  Dyami        |                     Type:  defect
  Caliri                             |
               Status:  new          |                 Priority:  normal
            Component:  avformat     |                  Version:
                                     |  unspecified
             Keywords:  ipcm endian  |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 Summary of the bug: When loading an mp4 file with ipcm audio, little
 endian, 24 bit, libavformat thinks it is big-endian. The resulting decoded
 samples are then 'static' due to the byte swapping.

 We are using libavformat/libavcodec to decode media files. I will upload a
 sample, 'ipcm_le.mp4'. !QuickTime player on macOS correctly identifies
 this is as little endian.

 Dumping the format after loading the audio shows this format:

 {{{
 Audio: pcm_s24be (ipcm / 0x6D637069), 48000 Hz, 1 channels, s32 (24 bit),
 1152 kb/s
 }}}

 My own inspection into these files suggests that there is a 'pcmC' sub-
 atom with a flag for endianness. I am not familiar enough with ffmpeg code
 to try to submit a patch.
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/9763>
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