Problems with jumpy video in velocity altered mpeg-2 renders

chewbonkay wrote on 12/6/2001, 7:54 AM
I'm finding it difficult to express this succinctly so please excuse -
I'm having a problem with excessively jumpy slow-motion video. I solved the problem for my .avi needs by choosing to pre-render and resample the slow motion parts and have printed from timeline to tape successfully. But now what do I do if I want to also render the same project as mpeg-2 for DVD?
The rendered mpeg-2 file again has jumpy slow-motion video. Should I render the entire project as an .avi then bring it back into Vegas and render as an mpeg? (God I hope not!) Should I render the slow motion part to a new track, delete the first track and render the whole project as .mpg? I hope I'm missing something obvious - please help!

As I've posted before, I never noticed jumpy video with changes in velocity in VF2 and I'm a little disappointed that this happens in VV3. All of my problems would be solved if only I didn't need to resample velocity altered sections.

Thanks very much in advance for any suggestions.

Comments

Cheesehole wrote on 12/6/2001, 1:57 PM
it doesn't matter what format you are rendering to. MPEG, AVI... just use the same filters and options you used to correct the problem when you rendered to AVI. set the problem events to resample. pre rendering is not necessary since you are not printing to tape. print-to-tape from the timeline is pointless with MPEG, so just render to a separate MPEG file.

if you are doing this already, and you are still getting jumpy video... is it jumpy in the same exact way as if you didn't use the 'resample' filter? does using the resample filter help at all?

- ben (cheesehole)
chewbonkay wrote on 12/6/2001, 4:06 PM
Cheesehole, I was unaware that one could set resample as a filter setting. To date, I have only seen references to "checking" the resample box under the custom option of the "Render As" .avi selection. (And acutally this is only for .avi. When choosing "Custom" under the mpeg setting, there is no such obvious "resample" box.) So what you are saying is that I can render my entire .mpg without having to resample the entire project thus wasting time, but instead, I can use filters to set which events are to be resampled within a non-resampled render? I apologize for not being aware of this. As I am away from my workstation now I can't check your suggestion but am sure you are correct.

I produce videos that run anywhere from 30-90 minutes and I'm sure you can see where if I choose to incorporate a few moments of slow motion during the production (let's say about 90 seconds) that cross fade with regular motion, having to resample the entire project as I render the .mpg would be time costly. If I were making 4 minute videos I wouldn't even bother posting about this.

Thanks.
SonyEPM wrote on 12/6/2001, 4:22 PM
Yes, you can check resample for events only. This is the best option if you only have a few events on the timeline with speed changes.

Just curious:

What is your source material for the slow-mo events?
Have you checked the output from a DVD player, or are you lokking at it in Media Player or another computer DVD player?

Cheesehole wrote on 12/6/2001, 4:59 PM
right click on an event and go to 'Switches' or 'Properties'
wvg wrote on 12/6/2001, 6:13 PM
I'm sorry to see this is a problem in VV also. I reported for Video Factory months ago. It seems certain MPEG files if imported to the timeline then rendered as a AVI pick up jitter that isn't part of the source file. Running same source file through competing products does not introduce the jitter. If there is no jitter in the source file and other video editors don't cause it, one would conclude Video Factory is doing something to the file. I wish Sonic Foundry would at least acknowledge this is an issue, then try to find out why.
chewbonkay wrote on 12/6/2001, 7:47 PM
Thanks all for your input.

SonicEPM:
"What is your source material for the slow-mo events?"
DV from Sony TRV330 via Firewire.

"Have you checked the output from a DVD player, or are you lokking at it in Media Player or another computer DVD player?"
The original shutter occurred in a Print-to-tape render that was seen on VHS output. The mpeg jumping was seen on media player. I never burned to DVD because the symptom was so similar to the aforementioned .avi.
Thanks again for the help on resampling events. That'll solve it for now.