Audio/Video Out of Sync

tellyaddict tellyaddict21 at
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
> points.
> 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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