[FFmpeg-trac] #11487(undetermined:new): displaymatrix side data carried through to output when overlay filter is used

[FFmpeg]

#11487: displaymatrix side data carried through to output when overlay filter is
used
-------------------------------------+-------------------------------------
             Reporter:  Wes Castro   |                     Type:  defect
               Status:  new          |                 Priority:  normal
            Component:               |                  Version:  git-
  undetermined                       |  master
             Keywords:               |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 Summary of the bug:

 When using an input with rotation metadata (`displaymatrix` side data)
 with the `overlay` filter, the rotation metadata will be carried through
 to the encoded output. Note that the pixels of the input will have already
 been "physically" rotated, effectively consuming the rotation metadata. If
 a transcode is made without the `overlay` filter the pixels are still
 rotated but the rotation metadata is dropped as expected.

 This has happened since at least FFmpeg 7.1 and on the master branch
 (bb87d19cd9720631d79e67a5ecca4659ae97734a). With FFmpeg 7.0 the issue
 doesn't reproduce (`displaymatrix` sidedata is dropped when the `overlay`
 filter is used)

 How to reproduce:
 * Generate rotated test video (1920x1080, rotated 90degs to 1080x1920
 during playback or transcoding) and test image
 {{{
 ffmpeg -y -display_rotation 90 -noautorotate -f lavfi -i
 smptebars=size=1920x1080:rate=30:duration=5 -pix_fmt yuv420p -c:v libx264
 -crf 12 ~/rotated_video.mp4
 ffmpeg -y -f lavfi -i smptebars=size=128x128:rate=1:duration=1
 ~/image.png
 }}}
 * Generate transcode **with** `overlay` filter
 {{{
 ffmpeg -y -i ~/rotated_video.mp4 -f image2 -framerate 30 -i ~/image.png
 -filter_complex "[0:v][1:v] overlay" ~/output1.mp4
 }}}
 ** FFprobe output of ~/output1.mp4:
 {{{
   Stream #0:0[0x1](und): Video: mpeg4 (Simple Profile) (mp4v /
 0x7634706D), yuv420p, 1080x1920 [SAR 1:1 DAR 9:16], 1433 kb/s, 30 fps, 30
 tbr, 15360 tbn (default)
       Metadata:
         handler_name    : VideoHandler
         vendor_id       : [0][0][0][0]
         encoder         : Lavc61.33.102 mpeg4
       Side data:
         displaymatrix: rotation of 90.00 degrees
 }}}
 ^^^ Note the `displaymatrix` side data

 * Generate transcode **without** `overlay` filter
 {{{
 ffmpeg -y -i ~/rotated_video ~/output2.mp4
 }}}
 ** FFprobe output of ~/output2.mp4:
 {{{
   Stream #0:0[0x1](und): Video: mpeg4 (Simple Profile) (mp4v /
 0x7634706D), yuv420p, 1080x1920 [SAR 1:1 DAR 9:16], 1358 kb/s, 30 fps, 30
 tbr, 15360 tbn (default)
       Metadata:
         handler_name    : VideoHandler
         vendor_id       : [0][0][0][0]
         encoder         : Lavc61.33.102 mpeg4
 }}}
 ^^^ Note there is no `displaymatrix` side data
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/11487>
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