[MPlayer-users] a few notes on AC3 passthrough in general (was SBLive AC3...)

[Arpi]

Hi,

> > Thanks for your help; I'm hoping someone can shed some light on the
> > A-V sync issues...
> 
> What sync issues exactly? I haven't experienced any (serious): A friend 
> of mine produced all my AC3 Divx movies so I can't exclude them from 
> beeing the point of failure, but I have to play them with delay -0.1 sec 
> to get lip-sync. Also after 1.5h there is a very small drift below the 
> 0.1 interval which I thus cannot correct. Again: I don't know if the 
> source is 100% ok. But I did not experience any _big_ drift-away yet, 
> perhaps try using '-ni' or '-nobps'.

AFAIK, the problem comes from buggy OSS driver of sblive!.
it doesn't implement well the GETODELAY ioctl for ac3 passthrough,
but mplayer relies on the returned value a _lot_.
(bad value can cause desync or hangup).
AFAIK it's a known driver bug/limitation but they don't seem to run
fixing it :(
maybe some workaround could help (the ac3dec and such external playback
programs and the threaded video players (aviplay,xine) don't use
GETODELAY ioctl so they may work...).

try ALSA, may help...
or try the commercial OSS drivers, may help... (they are time limited, but
if it work we know at least where the bug is)

good luck...

A'rpi / Astral & ESP-team

--
Developer of MPlayer, the Movie Player for Linux - http://www.MPlayerHQ.hu