[FFmpeg-trac] #3965(avcodec:new): Non-sense best effort timestamp
FFmpeg
trac at avcodec.org
Sat Sep 20 13:18:46 CEST 2014
#3965: Non-sense best effort timestamp
---------------------------------+---------------------------------------
Reporter: gjdfgh | Type: defect
Status: new | Priority: normal
Component: avcodec | Version: unspecified
Keywords: | Blocked By:
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
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Summary of the bug:
As you can see below, mp3 files which set skip_samples yield inconsistent
best_effort_timestamp values for the first and second frames.
The first frame has a duration of 0.001066 seconds, but if you subtract
the best effort timestamps of the second and first frame, you get
0.026122, a much higher value. Obviously the first frame's
best_effort_timestamp is broken. It should have the same value as pkt_pts.
Also, I would argue that the first timestamp should be 0 (i.e. libavcodec
shouldn't adjust the packet timestamp by the skip_samples amount), but
that's a different issue.
How to reproduce:
{{{
% ffprobe test.mp3 -show_frames
[FRAME]
media_type=audio
key_frame=1
pkt_pts=353600
pkt_pts_time=0.025057
pkt_dts=353600
pkt_dts_time=0.025057
best_effort_timestamp=0
best_effort_timestamp_time=0.000000
pkt_duration=15040
pkt_duration_time=0.001066
pkt_pos=417
pkt_size=417
sample_fmt=s16p
nb_samples=47
channels=2
channel_layout=stereo
[/FRAME]
[FRAME]
media_type=audio
key_frame=1
pkt_pts=368640
pkt_pts_time=0.026122
pkt_dts=368640
pkt_dts_time=0.026122
best_effort_timestamp=368640
best_effort_timestamp_time=0.026122
pkt_duration=368640
pkt_duration_time=0.026122
pkt_pos=834
pkt_size=418
sample_fmt=s16p
nb_samples=1152
channels=2
channel_layout=stereo
[/FRAME]
}}}
Patches should be submitted to the ffmpeg-devel mailing list and not this
bug tracker.
--
Ticket URL: <https://trac.ffmpeg.org/ticket/3965>
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