Audio/Video Out of Sync
tellyaddict21 at gmx.co.uk
Tue Aug 16 06:14:43 PDT 2016
> I've never tried the --raw option. Might it help with the following?
> A number of the files I fetched yesterday morning had reported missing
> segments. This specified time offsets in secs. I had a look at those
> In some cases there was no sign of a problem. In others the video froze
> for, say, ten sec, and when it resumed the video and audio seemed still in
> synch. But in other cases the synch was out.
> Would the synch offset effect be avoided by using --raw?
It should help yes :)
The idea is that when FFMpeg repackages the programme into a different format, it gets confused by the odd timestamps on the video and audio when there is a missing segment. Things then start to drift.
> If so, what other problems might that give? My first thought might be that
> the result would play with something like VLC without any timing. i.e. the
> total and elapsed times would be zero and attempts to jump to some point
> could cause problems with replay.
VLC seems to be coping fine with them. You can move through the file as normal.
> My assumption is that the pass though ffmpeg at the end of a fetch is to
> tidy up these issues. (It is something I have to do with ts files grabbed
> from DVB-T2.) But I am assuming/guessing this.
I think it's also to make files more compatible with different devices. Most probably wouldn't know what to do with a .ts file.
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