[FFmpeg-trac] #10494(avfilter:new): Incorrect h264 video generated after passing it through some of the filters.

[FFmpeg]

#10494: Incorrect h264 video generated after passing it through some of the
filters.
----------------------------------+--------------------------------------
             Reporter:  Wodzu     |                     Type:  defect
               Status:  new       |                 Priority:  normal
            Component:  avfilter  |                  Version:  git-master
             Keywords:            |               Blocked By:
             Blocking:            |  Reproduced by developer:  0
Analyzed by developer:  0         |
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 I have video like this:

 {{{
 Stream #0:0[0x1](und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv,
 bt709, progressive), 1280x720 [SAR 1:1 DAR 16:9], 26 kb/s, 25 fps, 25 tbr,
 12800 tbn (default)
 }}}


 provided in the attachment. I think any video with yuv420p(tv, bt709,
 progressive) will reproduce the problem.

 When I pass this video through some of the default filters , for example
 "edgedetect" and will try to encode it with libx264 codec, the video will
 be broken (black, some vertical strips etc.)

 This command illustrates the problem:

 {{{
 ffmpeg_g -i video.mp4 -vf "edgedetect" -c:v libx264 blank_video.mp4 -y
 }}}

 However, I've also found a filter for which the video is encoded fine:

 {{{
 ffmpeg_g -i video.mp4 -vf "pixelize" -c:v libx264 blank_video.mp4 -y
 }}}

 After some investigation, I think that the problem lies in automatic
 conversion of pixel format outputted by the filter and accepted by the
 codec.

 I've also tested this for libx265 and in this case it works correctly:

 {{{
 ffmpeg_g -i video.mp4 -vf "edgedetect" -c:v libx265 blank_video.mp4 -y
 }}}

 Tested on: multiple versions of FFmpeg (main branch and 6.0) and on custom
 built libx264 as well as official Ubuntu package.
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/10494>
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