rendering multiple projects concurrently.. stutter..

fongaboo wrote on 5/12/2002, 6:51 PM
Sometimes I render multiple projects concurrently (4-5) by running multiple instances of Vegas.. I'd imagine that this may actually be quite slower because of all the work the CPU has to do to manage the different processes - especially on my single 1gig PIII.. but a lot of times I find it easier to remote into my machine from work in the morning, start them up, and then they are done by the time I get back from night-class..

The thing is I am noticing some instances of stuttering in the resultant AVIs.. and I am thinking it might be a symptom of what I am doing. it doesn't really stutter as much as there are instances where it slows framerate dramatically for a brief moment.

Do you think rendering them in series, like a good little boy, will avoid me this?

Comments

fongaboo wrote on 5/12/2002, 8:54 PM
follow-up..

it looks like whatever is causing the 'stutter' is in the file itself.. I tried rendering to uncompressed.. then opening that file in a new project and rendering back to DV and the stutter still results.. I tried opening up the afforementioned uncompressed file in Premiere and rendering there as another DV file.. still stutter..

I finally tried opening the source DV file in Premiere, exporting it as another DV file and then substituting the newly rendered one into the Vegas project and that seemed to work - resultant renders of the project no longer lag/stutter in the spots they were.

The source DV file was captured in Vidcap 2.0 I believe. Any speculation on this behavior?
BillyBoy wrote on 5/12/2002, 9:15 PM
I can add I've seen similar things where a perfectly normal source file would produce jitter after rendering in Vegas Video. Same source file processed in other software did not produce jitter. Same source file first rendered in another application then worked on in Vegas was OK. Beats me. Hope I didn't jinx myself, haven't seen it for several months.
HPV wrote on 5/13/2002, 12:48 AM
Someone I mentioned this technic to said that it produced fragmented files onto the HD. Makes sense when you think about it. A little piece of this file, then that file, and so on. I wonder if the projects were rendering to their own HD partition could fix this ? All you need to do is copy the file to another HD and it will clean up (another partition ? ). That's faster than doing a defrag on the HD. The stutter won't be a problem except on files you want to print to tape. Everything else will end up being a file transfer that will produce a clean file. I guess it could cause a problem with CD/DVD burning also.


Craig H.

Caruso wrote on 5/13/2002, 12:48 AM
I've just completed the first of two two-hour sessions of a school musical. There is one instance of the sort of stutter/shudder that sounds similar to what you describe. The 'frequency' of the stutter almost seems to mimc visually what you hear as a disk drive reads/writes data.

It's only a guess, but, I think I may have experienced some sort of bog down during some sort of prerendering in that session (some times I'll selectively prerender to check on transitions, FX, etc) or something. Once corrupted, the stutter seems almost impossible to eliminate.

This was a three camera shoot with a totally independent audio only sound track (the stuttering affects the video only - it's not audible in any of the audio tracks).

Since the rest of the work came out really well (if I do say so myself), I haven't bothered to recapture the offending section and patch it in, although it would be easy enough to do.

As BillyBoy mentioned, it happens rarely. In my case, it seems to occur only in analog 8mm footage captured/converted to DV through my digital 8 camcorder. Frankly, my system is so wimpy (.9 gig/128meg RAM Athlon), that once I make any significant alterations to avi's during an editing session, all my previews that haven't been prerendered are so jerky, I wouldn't notice such a defect until after rendering the finished project.

Caruso
Caruso wrote on 5/13/2002, 12:58 AM
Oh, and, regarding your habit of rendering multiple projects, I haven't tried it . . . but, I tend to believe that rendering, while CPU intensive, is not that time critical in the same real-time streaming sense as capturing or printing to tape. I'm guessing that you don't save any processing time by rendering in this multiple instance manner, but you obvioulsy gain more efficiency by having your machine work longer for you in "unattended mode."

I wonder if Vegas has a batch render function. On the other hand, I guess, if you had enough contiguous file space, you could line all those projects up on a single timeline (each on a separate 'group' of tracks, if you like to easily maintain separate track FX, etc), and render one after the other, then, just select each project for separate printing to tape from the timeline.

A round about way to do things, but would be interesting to try.

Sorry to ramble, just thinking out loud.

Caruso