[MPlayer-users] Slower with sound ?

Arpi arpi at thot.banki.hu
Sat Oct 20 23:34:32 CEST 2001


> > you can say i'm wrong and mplayer should use such methods.
> > but just say which player is the best of all, in viewpoint of a-v
> > sync, speed and stability? this is the reason...
> Nahh.. it just sound strange to me to sync it to the system time.
> IMHO either audio should be synced to video or vice versa. The system
> clock has nothing to do with it.
agree. avifile uses system timer. nowdays it shifts time if it detects
a-v sync, but as i read on their list - it doesn't work properly.

sync to video is hard to implement.
1. video cards has no timer, at least what we can use for something
2. if you should shift audio timing - what are you doing? increase/
   decrease samplerate? not supported by most soundcards (drivers)
   and also sounds very funny. or just skip/duplicate chunks? even worse.

so the only and best way is using audio card's timer.
unfortunately GETODELAY and such ioctl()'s are at the advanced/experimental
section of OSS specs, so some _driver_ developer think it's not mandatory
to implement and they use dummy functions. :(

for users with broken drivers, i suggest using -ao sdl.
it has second thread for audio playback, and it needs only
write() blocking which is always work (it must work).
(my previous select() implementation did the same, but select()
was also broken in some drivers)

unfortunately we're living in a half-implemented and very buggy world...
we can either force users to buy perfect hardware (for example intel mb+cpu,
matrox g400 and sblive are good trio) or we should workaround bugs.

A'rpi / Astral & ESP-team

mailto:arpi at thot.banki.hu

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