[FFmpeg-trac] #401(avcodec:open): ffmpeg fails to decode MJPG in AVI

FFmpeg trac at avcodec.org
Fri Sep 9 22:36:03 CEST 2011

#401: ffmpeg fails to decode MJPG in AVI
             Reporter:  rectalogic  |                    Owner:
                 Type:  defect      |                   Status:  open
             Priority:  normal      |                Component:  avcodec
              Version:  git-master  |               Resolution:
             Keywords:  mjpeg       |               Blocked By:
             Blocking:              |  Reproduced by developer:  1
Analyzed by developer:  0           |

Comment (by michael):

 Replying to [comment:2 reimar]:
 > This is probably caused by libavfilter. The (vsrc)buffer filter seems to
 need a pixfmt from the start.
 > However the filters are created before the decoder is actually opened.
 > So it is completely reliant on the probe filling in the pix_fmt.
 > However since this file is non-interleaved and FFmpeg detects this too
 late, the probe never gets any video data, thus does not open the decoder
 and thus the pix_fmt is not filled in.
 > This seems all rather silly though: it is quite silly that it is not
 tried to open the decoder during probe even if no data is available, as is
 opening the decoder only after the filter has been set up.

 The decoder is opened in av_find_stream_info() but mjpeg can store a wide
 varity of pixel formats and iam not sure if the actually used one can be
 identified before the first frame.

Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/401#comment:5>
FFmpeg <http://ffmpeg.org>
FFmpeg issue tracker

More information about the FFmpeg-trac mailing list