Audio video sync issue on preview via DA-MAX+

John_Beech wrote on 11/6/2002, 12:48 PM

I route IEEE-1394 out of the computer to a black box from ProMax called a DA-MAX+ and then take Y/C to a monitor and audio to the mixer.

The problem is I don't get audio during preview unless I listen to the audio coming from the sound card (both the computer's sound card, and the audio-out from the DA-MAX+ go to the mixer).

This wouldn't be an issue except, a) there's no audio coming from the DA-MAX+ during playback (and this isn't a DA_MAX+ issue since there's no audio either when I replace the DA-MAX+ with a PD-150 camcorder), and b) the problem then becomes one of sync - or, more accurately, a lack of sync between the two. What I mean is that watching video on the monitor and listening to the audio from the soundcard means they are out of sync.

The A/V appears to be in sync just fine in reality, but during preview, i.e. while editing, they're not . . . which makes it tough to edit. Is this just me, or is this a recognized issue? Finally, is there a solution?

Comments

dcrandall wrote on 11/6/2002, 12:56 PM

John,

Nope, Vegas Video 3 does not output audio through the firewire while previewing your project. I don't know a way around this issue that's guaranteed to maintain Video/Audio sync.

jetdv wrote on 11/6/2002, 1:06 PM

You can adjust the sync. Go to Options - Preferences, Click on the Video Device tab, then change the "sync offset" slider (can be 0 to 8 frames & defaults to 4).

dcrandall wrote on 11/6/2002, 1:24 PM

jetdv,

Thanks for the input, I'm always learning new things about Vegas on this forum

John_Beech wrote on 11/6/2002, 1:45 PM

jetdv,

I saw that before but thought that affected 'all' audio/video sync . . . do you mean to say this only affects playback during 'preview' and not during print to tape functions?

John_Beech wrote on 11/6/2002, 1:51 PM

Further to the problem, I tried what jetdv suggested, but now I see where the sync seems to drift - it's not constant! I've returned the settings to the default but no change. Hmmm, I'm not sure what to do. Ideas anyone?

SonyEPM wrote on 11/6/2002, 2:11 PM

The issue is that there are multiple clocks involved, with no master reference.You can change sync offset for previewing, but for final output, you will want to prerender the audio using "print DV to tape" tool. This will ensure sync does not drift since the audio will be embedded in the dv stream.