[FFmpeg-trac] #5936(avcodec:closed): Colored haze in mpeg4 decoding (purple, yellow, ...) (was: Purple haze in mpeg4 decoding)

FFmpeg trac at avcodec.org
Tue Nov 22 01:31:00 EET 2016

#5936: Colored haze in mpeg4 decoding (purple, yellow,...)
             Reporter:  te36         |                    Owner:
                 Type:  defect       |                   Status:  closed
             Priority:  important    |                Component:  avcodec
              Version:  git-master   |               Resolution:  fixed
             Keywords:  asp          |               Blocked By:
  regression                         |  Reproduced by developer:  1
             Blocking:               |
Analyzed by developer:  0            |

Comment (by te36):

 Thank you for the quick fix!. Seems to be solving the issues.

 Suggested release-note/info for the bugfix:

 Certain encoder combinations (eg: mencoder/libxvid) can result in correct
 mpeg 4 part 2 encodings that also display correctly with non-ffmpeg based
 decoders (eg: windows media player) but that causes colored haze with
 ffmpeg decoding based application (eg: VLC, Kodi). This bugfix solves this
 decoding issue.

 Certain versions of FFMpeg caused incorrect mpeg 4 part 2 encodings that
 cause colored haze with ffmpeg and non-ffmpeg decoders. When decoding
 those encodings with a fixed version of ffmpeg, it recognizes the
 incorrect encoding by the FFmpeg version number encoded in the metadata of
 the media and activate a workaround for the decoding. This workaround can
 be manually invoked ("bug iedge"). The affected released versions of
 FFmpeg use libavcodec  [55.67.101... 57.64.100] or


 Checked video archive for encodings with buggy ffmpeg encoding. Luckily
 only one file.

 NOK file does display incorrectly with windows media player (non ffmpeg)
 and non-fixed ffmpeg. It does display correctly with fixed ffmpeg.

 OK files display correctly with windows media player and do play
 incorrectly with non-fixed ffmpeg/ffplay. They do play correctly with
 fixed ffmpeg/ffplay.

 Tried to re-create OK encodings that cause this problem, but can only
 recreate with mencoder/libxvid. Using ffmpeg/libxvid with same parameters
 does not cause problem at all. Maybe i was doing something wrong, if not
 then encoding problems might have been rare to ffmpeg users.

Ticket URL: <https://trac.ffmpeg.org/ticket/5936#comment:9>
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