[FFmpeg-trac] #8392(undetermined:new): ffprobe skip_frame nokey on wmv shows improper results
FFmpeg
trac at avcodec.org
Thu Nov 21 08:32:19 EET 2019
#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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