Drifting Preview Sync

farss wrote on 1/9/2008, 3:20 PM
I've mentioned this before but thought it was just running with the iZotopes plugs but it seems not so.

I created a simple sync test avi. Black with one frame white flash every second. Matching 1KHz pip. Monitoring on internal and external via firewire to D8 camera and then to Sony CRT.

In V7 all is in sync to start with but over around one minute of playback what V7 feeds out the firewire port drift out of sync by several frames. I know it's Vegas because I'm also watching the LCD on the D8 camera. Initially both the preview monitor and the D8 LCD flash in sync and then loose it.

I run the same AVI test file in V6 and no problem. I haven't tried this with V8 as the PC with all my monitoring and audio gear needs to be migrated to XP before I can run V8. Has anyone tested this in V8?

This really is a major PIA when you've got a musician for a client, watching. You setup a good CRT so he can see but then the audio drifts and he spends more time bitching about you getting things out of sync. You stop playack and it's back in sync....for a while.

To get around this I now figure I'll have to render out of V7 and playback the AVI in V6, groan.

Bob.

Comments

Grazie wrote on 1/10/2008, 2:25 AM
Bob, I have repeated your test and don;t see any outta sync. I'll also try V7 too.

I did a render of the test and placed that back ON the timeline and it is syncing nicely. But I will try Vegas 7 too.

Grazie
farss wrote on 1/10/2008, 2:31 AM
Thanks,
not a major issue. I got through the drama with the client visit today and he's very happy. I'll see if I can get the OK to show the finished project. The footage is from Bromley, not too far from your neck of the woods I think. Beautiful old church, great organ music, once I stitched all the takes together.

Bob.
Grazie wrote on 1/10/2008, 2:43 AM
Were you getting this with NON rendered media? Meaning just repeats of the setup: Black/White and the tone just there in the timeline? Or was it with a rendered AVI, placed back on the timeline?

Grazie
farss wrote on 1/10/2008, 3:16 AM
Rendered media and not rendered media. That's the bit that really threw me. I rendered the whole project out, bought it back into a new project and same thing. Taking the same avi into V6, perfecto.

Bob.

UKAndrewC wrote on 1/10/2008, 12:38 PM
I get this problem too. If I just stop, move the cursor somewhere else and start again it's in sync.

I have reported it to Sony but I didn't get any response

Andrew
rmack350 wrote on 1/10/2008, 3:03 PM
I've had this problem in V7 and V8 in NTSC DV projects. I wonder if there's some sort of sample rate mismatch happening. I remember some long past problem with sound blaster cards where the card would convert everything to 48bit internally. Can't remember why this was a problem or even what it related to, just illustrating that things could change even after the audio leaves Vegas.

Rob Mack
farss wrote on 1/10/2008, 4:35 PM
Whatever is happening it's not the audio, it's the video that's slipping.
The audio and video on the internal preview stay in sync. The video going down the firewire to the external monitor slides out of sync with the internal preview monitor and audio. And I'm using a M-Audio Firewire 410 for the audio off it's own firewire port via ASIO drivers. Hm, or am I, must check which drivers Vegas is using, that could be a clue although I doubt it.

And thanks to those that have responded, it's good to know I'm not alone.

Bob.
rs170a wrote on 1/10/2008, 4:59 PM
No Bob, you're not alone.
I noticed it on my work machines when I installed V7 on them too.
Sync was perfect in V6 but off in V7.
As you mentioned, internal preview is OK but not on an external monitor.
BTW, I'm using the 410 on it's own firewire port as well.

Mike