[FFmpeg-trac] #1881(avformat:open): in24 Little Endian PCM audio (pcm_s24le) in mov decoded incorrectly as Big Endian (pcm_s24be)

FFmpeg trac at avcodec.org
Mon Nov 5 12:26:42 CET 2012

#1881: in24 Little Endian PCM audio (pcm_s24le) in mov decoded incorrectly as Big
Endian (pcm_s24be)
             Reporter:  irius         |                    Owner:
                 Type:  defect        |                   Status:  open
             Priority:  normal        |                Component:  avformat
              Version:  git-master    |               Resolution:
             Keywords:  mov in24 pcm  |               Blocked By:
             Blocking:                |  Reproduced by developer:  1
Analyzed by developer:  0             |

Comment (by cehoyos):

 Replying to [comment:11 irius]:
 > Replying to [comment:10 cehoyos]:
 > > Replying to [comment:8 irius]:
 > > > I attached a screenshot of dumpster.exe where you can see an unknown
 data field with the hex-value "0x656e6461" ('enda' in ASCII).
 > >
 > > The relevant information is in the following 16 bit ("0001"), but
 don't you agree it is interesting that Dumpster also fails to recognize
 the file as QuickTime-compatible (which it isn't, it fails at least with
 QuickTime 7.7.2)?
 > Thanks!. I believed that the reason Dumpster didn't recognize this atom
 was that it is outdated, and Apple introduced this atom quite "recently",
 so it doesn't know how to decode newer structs.

 The page I used for debugging was from 2006 and I suspect the atom was
 there significantly longer.

 > Making it clear that I am a total newbie in "MOV" and QuickTime, what do
 you mean by "QuickTime compatible"? I can play the file on my Quicktime
 7.7.2 (1680.56) (Windows 7).

 It fails here on vanilla Windows QuickTime.
 (Perhaps you have installed some part of the Matrox software that includes
 support for it?)

 > I reviewed the patches, and as far as I can understand (which is not too
 far indeed) it has to do with Matrox branding the file as "JUNK" which
 causes ffmpeg to not treat it as a regular QT mov file, and as a side
 effect the "enda" atom is not processed. Is it so?

 Apart from the question if mov is "regular" or isom/mp4: Yes (but it is
 not the enda atom - that would be always processed - but the "QuickTime
 version 1" audio fields before the enda atom that should not be present in
 non-QuickTime files and that Dumpster also fails to recognize.)

 > Anyway, it's quite impressive that in a couple of days there are already
 2 possible fixes to this.

 The patches were there in less than a day;-)

Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/1881#comment:12>
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