Why does straight DV pre-render?

PeterWright wrote on 8/17/2004, 9:30 PM
The first 3 mins of a project is a standard PAL DV clip, without any FX applied, either to the Event or Track

The Composite slider is at 100%. Project settings are standard DV.

Yet, when I "selectively" prerender, it is not being selective at all - everything is being prerendered, whether it needs it or not.

Any ideas why pre-render is happening? - I must be overklooking something.

(I have a pair of Parent/Child tracks above the main video, but nothing in them till much later on down the time line. Could that cause this?)

Comments

farss wrote on 8/17/2004, 9:32 PM
Peter,
I've noticed much the same in a different way. Having empty tracks
affects render time. Curious.

Bob.
Spot|DSE wrote on 8/17/2004, 9:39 PM
The audio has to set up the Wav64 files for playback. Or alternatively, it's buffering those audio sections. If the Parent/Child has 3D, that seems to affect the pre-render space no matter what. There are some issues with rendering and 3D that a few have commented on.
PeterWright wrote on 8/17/2004, 10:28 PM
Thanks for the replies guys - gave me an idea - just tried something and it at least answered my question..

I muted the Parent/Child tracks and sure enough the pre-render skipped past the "straight" DV event to where rendering was really required. There's no 3D involved Spot, but it still does this.

So, when there are Parent/Child tracks, it renders everything, so I may as well render to new track - this will make PTT less problematic - still get occasional audio drops when printing straight from timeline with pre-renders.
Chienworks wrote on 8/18/2004, 5:06 AM
This shouldn't make any difference with potential dropouts on PTT. Vegas will not start the PTT process until it believes that everything is prerendered to straight DV and W64 no matter what is on the timeline or where you are in rendering/prerendering when you ask it to PTT. If you're getting dropouts on PTT then it's due to some other problem.
PeterWright wrote on 8/18/2004, 6:49 AM
I'm sure you're technically right, Kelly, but most times that I've used PTT from the timeline I've had audio dropouts, whereas if I render to a single avi and go out from the Capture utility I've never had a problem.

I'd guess that the latter process, from a single file, must be easier on the system than from the various sources/prerenders on the timeline.
farss wrote on 8/18/2004, 7:05 AM
Might have something to do with fragmentation of the files. Certainly any audio and video that's in separate files during PTT will require the heads to do much more seeking. Actually thinking that through fragmentation maynot be as big an issue as physical distance between files on the drive. And a further thought, having say the audio on one drive and the video on another might help.

Still rendering to a new file isn't that dig a deal, I tend to do it as a matter of course anyway.

Bob.
Spot|DSE wrote on 8/18/2004, 9:09 AM
Peter, do you have Wav64 enabled in your prefs? Shouldn't matter, but it might. I've not tried PTT without it enabled. I think it defaults to wav 64 regardless, but I could be wrong.
As Kelly said, I'd look at fragmenting or resource stealing next.
PeterWright wrote on 8/18/2004, 7:59 PM
Thanks for the suggestion Douglas - I did not have W64 enabled, but it now is and I'm Printing to tape this afternoon - I'll report back.

Peter