[FFmpeg-trac] #5178(avformat:new): isom cannot be a MAJOR BRAND in MP4 created from ffmpeg

FFmpeg trac at avcodec.org
Fri Jan 22 17:57:48 CET 2016

#5178: isom cannot be a MAJOR BRAND in MP4 created from ffmpeg
             Reporter:               |                    Owner:
  richardbushell                     |                   Status:  new
                 Type:  defect       |                Component:  avformat
             Priority:  normal       |               Resolution:
              Version:  unspecified  |               Blocked By:
             Keywords:  mov          |  Reproduced by developer:  0
             Blocking:               |
Analyzed by developer:  0            |

Comment (by richardbushell):

 I need to know definitively if ffmpeg is writing MP4v1 or MP4v2, so mp41
 or mp42. Whichever it is that should be written as the Major Brand. The
 Minor Version should be 0 unless you know otherwise.

 Isom should not be the Major Brand, just a Compatible brand. So, we need
 to change this, not just the Minor Version.

 We don't use MP4Box in our workflow at all for any other purpose other
 than just to write the Major Brand and Version Number. If we don't change
 this then the standard ffmpeg mp4 output file fails conformance
 complaining of isom being used as a Major Brand. MP4Box is only changing
 the Brand and Version Number, nothing else.

 I can work through the problem, but as a starting point we need to know if
 ffmpweg is writing mp41 or mp42. If mp41 (as you think) then changing the
 brand to mp41 also results in a Conformance error (as in my post above
 about ImageDescription width and height being >320 and >240 respectively.
 Is mp41 standard constrained to sizes < 320x240 ???

 When we change the brand to mp42 it does pass conformance (but you don't
 think it is mp42).

 Can you find out if ffmpeg is actually writing mp42 (not mp41)? Whatever
 brand flags need recording is based on knowing this. We can then work
 through the issue, maybe just needs these values changing in

Ticket URL: <https://trac.ffmpeg.org/ticket/5178#comment:10>
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