libavformat muxers destroy initial timestamp offsets
|Reported by:||Stefano Sabatini||Owned by:|
|Version:||unspecified||Keywords:||muxer timestamp flv avi|
|Blocking:||Reproduced by developer:||no|
|Analyzed by developer:||no|
Description (last modified by )
Many muxers in libavformat (tested: avi, flv) destory the initial offset.
This is meant as a feature, but has the effect that remuxing a file will destroy the original timestamp information. This is especially annoying in case streams from different sources need to be synched.
How to reproduce:
ffmpeg -f lavfi -i "aevalsrc=sin(2*PI*400*t)::d=5,asetpts=PTS+10/TB" -y out.flv
then check the packet timestamps with ffprobe -show_packets out.flv.
A possible workaround:
ffmpeg -f lavfi -i "aevalsrc=sin(2*PI*400*t)::d=5,asetpts=PTS+10/TB,aresample=min_comp=0.001:min_hard_comp=0.0010" -y out.flv
(with video the problem can't be easily worked around).
The behavior with respect to the initial offset could be made configurable through some options.