Re: [xine-user] Shuttle XPC SN41G2 and SPDIF

[Michael R. <mr...@us...>]

Hi Brad,

> I think I have pretty picky hearing, I can hear a 30ms blip in the audio
> but given what I have seen most other people put up with I guess they would
> not.

My ears are also quite demanding when it comes to audio sync, but here, both 
AC3 and DTS passthrough are in perfect sync, at least with DVDs.

> From right out of left field, given we have no control over the audio
> playback rate when using passthrough, what about syncing the video and
> master clock to the audio output?

That's exactly what's being done when the sync method "feedback" is used. The 
difference between the sample the soundcard is playing and the sample it 
should be playing is monitored (that is the gap value James told you about). 
When it exceeds a certain limit, a drift value is fed back into the metronom 
sync engine, which applies a soft speed correction to the video. When this 
happens, `xine --verbose=2` should show a message "fixing sound card drift 
by ... pts".

The only problem I can imagine is the sound driver reporting incorrect values 
about what the card is actually playing.

Michael

-- 
/* Fuck.  The f-word is here so you can grep for it :-)  */
	2.4.3 linux/include/asm-mips/mmu_context.h