[FFmpeg-trac] #8392(undetermined:new): ffprobe skip_frame nokey on wmv shows improper results

[FFmpeg]

#8392: ffprobe skip_frame nokey on wmv shows improper results
-------------------------------------+-------------------------------------
             Reporter:  emmdev       |                     Type:  defect
               Status:  new          |                 Priority:  normal
            Component:               |                  Version:
  undetermined                       |  unspecified
             Keywords:               |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 Summary of the bug:
 How to reproduce:
 {{{
 ffprobe -select_streams v -show_entries
 frame=key_frame,pkt_dts_time,best_effort_timestamp_time,pict_type
 -sexagesimal inputfile.wmv
 vs
 ffprobe -select_streams v -skip_frame nokey -show_entries
 frame=key_frame,pkt_dts_time,best_effort_timestamp_time,pict_type
 -sexagesimal inputfile.wmv
 }}}

 Result for all frames (excerpt):
 {{{
 [FRAME]
 key_frame=0
 pkt_dts_time=0:00:09.976000
 best_effort_timestamp_time=0:00:09.976000
 pict_type=P
 [/FRAME]
 [FRAME]
 key_frame=0
 pkt_dts_time=0:00:10.009000
 best_effort_timestamp_time=0:00:10.009000
 pict_type=P
 [/FRAME]
 [FRAME]
 key_frame=1
 pkt_dts_time=0:00:10.043000
 best_effort_timestamp_time=0:00:10.043000
 pict_type=I
 [/FRAME]
 [FRAME]
 key_frame=0
 pkt_dts_time=0:00:10.076000
 best_effort_timestamp_time=0:00:10.076000
 pict_type=P
 [/FRAME]
 }}}

 Result for just keyframes / skip_frame nokey (excerpt):
 {{{
 [FRAME]
 key_frame=1
 pkt_dts_time=0:00:10.009000
 best_effort_timestamp_time=0:00:10.009000
 pict_type=I
 [/FRAME]
 [FRAME]
 key_frame=1
 pkt_dts_time=0:00:20.019000
 best_effort_timestamp_time=0:00:20.019000
 pict_type=I
 [/FRAME]
 }}}

 I've only supplied the corresponding "all frames" entries for the first
 entry of the "just keyframes" output, to keep it shorter.

 It shows "all frames" listing the keyframe at 0:00:10.043000 when
 skip_frame nokey lists it at 0:00:10.009000, a timestamp which corresponds
 to a P frame.

 On mp4/avc it's a mixed bag. When using pkt_dts_time, it behaves the same
 as above, but when using pkt_pts_time it works fine, both outputs (all &
 keyframes) show the same matching timestamps.

 The file in question is really large, so I can't upload it, wmv/wvc1, has
 no pkt_pts_time (i.e. it's N/A), which is why I used pkt_dts_time and
 best_effort_timestamp_time (which in this case seems to be one and the
 same).

--
Ticket URL: <https://trac.ffmpeg.org/ticket/8392>
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