[FFmpeg-trac] #1767(avformat:new): 24bit audio in mov is flagged as 16bit in stsd atom

FFmpeg trac at avcodec.org
Mon Oct 1 09:46:22 CEST 2012

#1767: 24bit audio in mov is flagged as 16bit in stsd atom
             Reporter:  nichot20    |                    Owner:
                 Type:  defect      |                   Status:  new
             Priority:  normal      |                Component:  avformat
              Version:  git-master  |               Resolution:
             Keywords:  mov         |               Blocked By:
             Blocking:              |  Reproduced by developer:  0
Analyzed by developer:  0           |

Comment (by nichot20):

 Replying to [comment:3 muken]:
 > According to qtff.pdf, when a sound sample description is version=1 or
 2, sample size field shall be set to 16.
 > So, it is not a bug.
 > The actual sample size is placed more downward.
 > Early sample size field shall be ignored by readers.

 I note that both the original, and stream copied file have stsd version=0,
 not the 1 or 2 you mention.

 Looking at the code the value is set based upon the value of AV_CODEC_ID_*
 when (version != 2) and comparison with the original file shows that
 Quicktime Pro uses a value of 24.

 The only other differences to the original file seems to be that QT Pro
 adds in the extended version info which ffmpeg only adds for version 1
 (line 672)

Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/1767#comment:5>
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