[FFmpeg-trac] #11055(avcodec:reopened): OGOP (Open GOP) in certain conditions may cause missing frames of decoding

[FFmpeg]

#11055: OGOP (Open GOP) in certain conditions may cause missing frames of decoding
-------------------------------------+-------------------------------------
             Reporter:  markfilipak  |                    Owner:  (none)
                 Type:  defect       |                   Status:  reopened
             Priority:  normal       |                Component:  avcodec
              Version:  git-master   |               Resolution:
             Keywords:  everything   |               Blocked By:
  OGOP                               |
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
Comment (by markfilipak):

 > ͏    Probably you just have some reading difficulties... No matter.

 I have difficulties reading what you write, that's for sure.

 > ͏    comment:167 is mostly of optimization instructions.

 I didn't understand what you wrote.

 > ͏    And I may speculatively guess a lot things rather accurately.

 Do you care to share your speculations?

 > ͏    It appears the origin inputs ("00305.m2ts", "00306.m2ts"; that used
 to generate "Ticket_11055.m2ts") may be decoded without similar problem.

 It appears [that] the origin [original] inputs ("00305.m2ts",
 "00306.m2ts"; that [were] used to generate "Ticket_11055.m2ts") may be
 decoded without similar [?] problem.

 I did not decode 00305.m2ts or 00306.m2ts.

 > ͏    Bad slice mostly.

 "Slice" as in macroblock slice? Or slice as in cutting, as in making a
 clip?

 > ͏    Do you have further questions?

 Yes.

 Question 1:
 Why do the timestamps in this:

     ffmpeg -copyts -i Ticket_11055.m2ts -map 0:v -vf showinfo -c:v
 rawvideo -f null -muxdelay 0 - 2>Ticket_11055.m2ts_showinfo.txt

 differ from the timestamps in this:

     ffmpeg -i Ticket_11055.m2ts -map 0 -copyts -c copy -dn -sn -f framecrc
 - >Ticket_11055.m2ts_framecrc.txt

 Note that the timestamps in framecrc match the actual packets in
 Ticket_11055.m2ts.

 Question 2:
 Why do the timestamps in this:

     ffprobe -sexagesimal -select_streams v -show_frames -of flat -i
 Ticket_11055.m2ts >Ticket_11055.m2ts_show_frames.txt

 differ from the timestamps in this:

     ffmpeg -i Ticket_11055.m2ts -map 0 -copyts -c copy -dn -sn -f framecrc
 - >Ticket_11055.m2ts_framecrc.txt

 Note that the timestamps in framecrc match the actual packets in
 Ticket_11055.m2ts.

 Thank you.
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/11055#comment:170>
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