[FFmpeg-trac] #10493(undetermined:new): Incorrect FPS when creating webm dash files

[FFmpeg]

#10493: Incorrect FPS when creating webm dash files
-------------------------------------+-------------------------------------
             Reporter:  Aleksandar   |                     Type:  defect
  Milovanovic                        |
               Status:  new          |                 Priority:  normal
            Component:               |                  Version:  6.0
  undetermined                       |
             Keywords:               |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 Summary of the bug:

 I am trying to transcode from image sequence to webm dash streaming files.
 I can do that successfully, but ffprobe shows invalid FPS for those
 afterwards (in this example, 30.30 instead of 30). If I just copy codec
 into new webm file from dash, it still provides invalid FPS info.

 Everything mentioned does not happen for mp4 dash streaming files (they
 have correct FPS all the time).

 Note that manifest.mpd has a property inside stating frameRate="30/1", but
 that is ignored by the ffprobe.



 How to reproduce:

 # ffmpeg version is 6.0-essentials_build, but it is the same with 5.1, and
 I guess others (don't think this is a regression)
 # I will attach a very small repro of just 3 jpg files that can be used to
 reproduce the issue

 # Create webm dash manifest in question, with 30 fps input creates files
 that are described with 30.30 fps
 ffmpeg -y -framerate 30 -i "img_%2d.jpg" -c:v libvpx-vp9 -f dash
 -dash_segment_type webm manifest.mpd
 ffprobe manifest.mpd

 # Even after moving to webm container (without reencoding), fps is still
 30.30
 ffmpeg -y -c:v libvpx-vp9 -i manifest.mpd -c copy out.webm
 ffprobe out.webm
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Ticket URL: <https://trac.ffmpeg.org/ticket/10493>
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