[reggieBannister]

Thought I would post my syptoms, and see if any of you guys have the same problem:

Macbook Pro, C2d 2.0Ghz, DVI->HDMI into Sony X3000

I used Tufty's switchResX settings to get my Bravia to read the signal as 1080p / 24p.

When I i play any 720p MKV's from the laptop's local drive (29.976fps), I get pretty much smooth playback, with the odd dropped frame here and there. The problem is that the Audio is almost always slightly out of sync.

It seems as though it will slip further and further out of sync untill there is a slight audio pop / dropout and then will sync up again, only to slowly go out of sync again.

In a possibly related problem, I have a windows machine wirelessly sharing a load of TV episodes, which I was amazed to see OSXBMC add to the library. Problem is, with any file played over the network (HDTV rips, DVD rips etc) the audio will always slip out of sync. It only takes about 5 mins and it is unwatchable. The only remedy is to skip backwards / forwards to reset the sync.

Anyone else have any of these problems / offer a solution?
Thanks in advance

[elan]

Playing videos in 24p mode is known to be quirky. However, your post seems to indicate that you're playing 29.976fps videos in 24p mode. This is a no-no, for hopefully obvious reasons, and will lead to such things.

If you simply mistyped, and you are playing 24p videos in 24Hz refresh rate, make sure your refresh rate is actually the 23.976Hz, which might help.

-elan

[reggieBannister]

Thanks for the reply elan,

You are right I was using Tufty's 24p settings not the 23.976 ones, this could explain the drifting audio when playing local files. I will apply the 23.976 settings with switchresX later and let you know if that helps.

Out of interest, why are BDrips, DVD rips etc not 24 frames a second? Is anything actually 24 frames a second? Like the Cinema? Or is it shorthand because no one bothers to say 23.976?

I still feel that the network audio syncing is a different problem as it is so much worse, and never fixes itself - perhaps something to do with the buffering of the file?

[elan]

Out of interest, why are BDrips, DVD rips etc not 24 frames a second? Is anything actually 24 frames a second? Like the Cinema? Or is it shorthand because no one bothers to say 23.976?

Yeah, it's shorthand. Nothing commercial is a nice round 24 or 30 frames a second, AFAIK.

-elan