[FFmpeg-trac] #5023(avformat:open): Can no longer read mjpeg from Mobotix camera

[FFmpeg]

#5023: Can no longer read mjpeg from Mobotix camera
-------------------------------------+-------------------------------------
             Reporter:  hackeron     |                    Owner:
                 Type:  defect       |                   Status:  open
             Priority:  important    |                Component:  avformat
              Version:  git-master   |               Resolution:
             Keywords:  mjpeg        |               Blocked By:
  mpjpeg regression                  |  Reproduced by developer:  1
             Blocking:               |
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------

Comment (by w3sip):

 The main disadvantage is that the remainder of the data (e.g. MIME
 headers) are being passed to the decoder resulting in
 avcodec_decode_video2 returning an error:

 [ffmpeg's output] FFMPEG >> decode frame unused 68 bytes
 [ffmpeg's output] FFMPEG >> No JPEG data found in image
 [our output]  Error decoding video - err=-1094995529 Invalid data found
 when processing input

 The only way to make mjpeg demux work in this situation is to not check
 for errors from avcodec_decode_video2, or ignore those -- possible, but
 pretty dirty.

 The best solution would be to keep mpjpeg demux, but remove the dependency
 on Content-Length (since it's technically not required by MIME), and do a
 proper multipart MIME parsing (skip the headers, consume the body until
 the next boundary). I could look at it, but likely not in the next week or
 two.

--
Ticket URL: <https://trac.ffmpeg.org/ticket/5023#comment:10>
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