[FFmpeg-trac] #10408(avcodec:new): decoder sometimes reporting pts values in incorrect order

[FFmpeg]

#10408: decoder sometimes reporting pts values in incorrect order
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             Reporter:  csab6597  |                     Type:  defect
               Status:  new       |                 Priority:  normal
            Component:  avcodec   |                  Version:  6.0
             Keywords:            |               Blocked By:
             Blocking:            |  Reproduced by developer:  0
Analyzed by developer:  0         |
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 Decoding video data through C api I found that in some situations the
 frames coming out of the `avcodec_receive_frame()` function have their pts
 values not in the correct order, whilst the picture data itself seems to
 be in correct - that is display - order.
 Check the video file provided. Have a look at the pts values by
 {{{
 ffprobe 02.mp4 -show_frames -select_streams 0
 }}}
 excerpt
 {{{
 ...
 [FRAME]
 pts=478478
 pkt_dts=480480
 pict_type=P
 coded_picture_number=478
 [/FRAME]
 [FRAME]
 pts=479479
 pkt_dts=481481
 pict_type=P
 coded_picture_number=479
 [/FRAME]
 [FRAME]
 pts=481481
 pkt_dts=482482
 pict_type=B
 coded_picture_number=481
 [/FRAME]
 [FRAME]
 pts=480480
 pkt_dts=483483
 pict_type=P
 coded_picture_number=480
 [/FRAME]
 [FRAME]
 pts=482482
 pkt_dts=484484
 pict_type=P
 coded_picture_number=482
 [/FRAME]
 ...
 }}}
 You find that the pts values are in proper order up to
 codec_picture_number=479

 Probably because suddenly a B frame is coming up, the next frame in the
 list is reported to be 481, but when looking at the raw image data in the
 `AVFrame` of that frame, it is indeed frame number 480 to be displayed. So
 the remedy for me right now is to swap the pts values between 480 and 481.

 In the file provided this mixup will repeat again several times.
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/10408>
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