[FFmpeg-trac] #9304(ffmpeg:new): Video Becomes Unplayable After -c:v copy

[FFmpeg]

#9304: Video Becomes Unplayable After -c:v copy
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             Reporter:  Zack Bloom  |                     Type:  defect
               Status:  new         |                 Priority:  normal
            Component:  ffmpeg      |                  Version:  git-master
             Keywords:              |               Blocked By:
             Blocking:              |  Reproduced by developer:  0
Analyzed by developer:  0           |
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 Summary of the bug: A working video file becomes invalid after a simple
 copy

 How to reproduce:
 {{{
 % ffmpeg -i broken-example.mp4 -c:v copy out.mp4
 ffmpeg version N-102791-gaca923b365
 built with Apple clang version 12.0.0 (clang-1200.0.32.29)
 }}}

 You can obtain broken-example.mp4 (3.5MB) here:
 https://www.dropbox.com/s/tky9p7jmoe8tx4z/broken-example.mp4?dl=1

 This began as much more complex failed encoding operation, but this test
 case is so trivial I believe it will be easier to debug. This input is
 successfully playable using Quicktime on OSX (although it can't be played
 with some other players).

 What you observe is it begins with a normal video clip, followed by what
 seems like a slideshow frame. My guess is it is using a variable frame
 rate to deliver the final slideshow image, but I am unsure how to
 determine this using ffprobe.

 After the encoding the file returned by ffmpeg appears corrupt where the
 'slideshow' frame began, approx 9 seconds into the original clip.

 For anyone who does not have a Mac with Quicktime, I have prepared a
 screen recording of the successful playback of the original video here:
 https://www.dropbox.com/s/qs5ssk8832s5dek/example-playback.mp4?dl=1

 I have no doubt the input video file is broken in some way, but I would
 still like for ffmpeg to be able to operate with it if possible. Thank you
 for all the work you do to create this incredibly powerful tool.
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/9304>
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