Audio-Video sync, av-delay request

[morfeus2]

Since many years I have a-v sync problems with recordings (with transcoding) from DVB-T. It's not so big as the one mentioned here #92 (comment) but a bit annoying. Of course they play fine on PC (Debian/mplayer). I ended up by encoding them a bit out of sync in such a way that they play fine on raspberry, and adjust the a-v delay live, when watching on PC with mplayer.
Instead of trying to understand the problem and fix it for this specific format I would propose a more general approach: could you implement a feature like mplayer, where it is possible to adjust a-v delay while playing? It would be extremely useful both to fix issues like this case and also allow to directly watch malformed video that are really out of sync, without the need to transcode them before.
Furthermore, since raspberry is often used as a display in public (for eg. in kiosks and shows, fairs etc..), it can happen that audio and video output follow different paths through different devices that maybe have not equal processing times.
Of course this is my personal opinion.