Opened 8 months ago
Closed 8 months ago
#7299 closed defect (worksforme)
Seeking mp4 makes audio/video out of sync
Reported by: | hadmut | Owned by: | |
---|---|---|---|
Priority: | normal | Component: | undetermined |
Version: | unspecified | Keywords: | |
Cc: | Blocked By: | ||
Blocking: | Reproduced by developer: | no | |
Analyzed by developer: | no |
Description
Hi,
I'm trying to cut parts from a video with ffmpeg 2.4.2 (ubuntu 18.04) and get videos where audio and video are in most cases out of sync, although there are cases, where they are still in sync.
E.g. the video
taken from
https://download.media.tagesschau.de/video/2018/0701/TV-20180701-2348-2001.websm.h264.mp4
ffmpeg -loglevel warning -ss "00:22:39.000" -i TV-20180701-2348-2001.websm.h264.mp4 -t "00:00:06.010" -map 0 -c copy g1.mp4
ffmpeg -loglevel warning -ss "00:22:40.000" -i TV-20180701-2348-2001.websm.h264.mp4 -t "00:00:05.010" -map 0 -c copy g2.mp4
ffmpeg -loglevel warning -ss "00:22:39.500" -i TV-20180701-2348-2001.websm.h264.mp4 -t "00:00:05.710" -map 0 -c copy g3.mp4
only g1.mp4 is in sync. Seems as if this accidently hit the beginning of a frame group.
Change History (2)
comment:1 Changed 8 months ago by hadmut
comment:2 Changed 8 months ago by cehoyos
- Resolution set to worksforme
- Status changed from new to closed
- Version changed from 3.4 to unspecified
Please understand that only current FFmpeg git head is supported on this bug tracker.
In any case, I cannot reproduce A/V desync for the given sample and command line.
Seems to be the video copy compression.
replacing the -c copy with -c:a copy or removing all -c options keeps the video in sync.
Using just -c:v copy shows videos out of sync.
Two of the videos I have trouble with: