Got a long render? Here's a tip to help out.

TheHappyFriar wrote on 7/14/2006, 10:49 AM
I have a render that I KNOW will take at least 28 hours, probley more. Problem is one of my kids could easily (and has already) hit the cancel button in vegas & I lost ~12 hours of render. So, I decided to try something different.

I set up regions ~8:30 each in series along the entire 45 minute area. I then used the batch render to render out along the regions. So instead of one long/huge AVI I have 5 smaller AVI's, but they all render in 1/5th the time. So, if something goes wrong (power out, cancel button hit, etc) I don't loose the whole render, I jsut loose the segment it's on. :)

Comments

dand9959 wrote on 7/14/2006, 11:29 AM
Could you maybe start the 28 hour render, and then change your system clock to be, say, 27 hours ahead, thereby reducing your render time to under an hour?
Sol M. wrote on 7/14/2006, 11:30 AM
Yeah, that's a good method. That's why I render all CG/VFX stuff from other apps as image sequences. If the render goes sour, you just have to continue from where it stopped at. Vegas can't do image sequences (efficiently), but your method is a good substitute. Too bad it's only employable with file formats that can be easily recombined (can't be done with AC3, WMV, MP4, etc.)
TheHappyFriar wrote on 7/14/2006, 11:39 AM
don't worry about render times... it resets to 0 at the 24 hour mark. :)

You can join mpeg-1/2 via tmpgenc. I've done that several times. but ac3, wmv & mp4 are iffy. But, i don't consider that a big deal. I render all my fx/edits to AVI so then the render to the final format takes realtively no time. IE it will take ~100 hours for my entire project, audio FX, media FX, etc. to render to DV AVI but perhaps 3/4 hours of that to mpeg-2/ac3 for DVD.
Jayster wrote on 7/14/2006, 12:43 PM
When you use prerendering in Vegas, like with AVI format as an example, is it only benefitting previews? Or will it actually pull in and stitch together the prerendered files for a real render?

It sure would be nice if Vegas could do that.
TheHappyFriar wrote on 7/14/2006, 1:04 PM
i'm rendering NTSC DV AVI's with no audio (as I don't need the audio done right now) so i just put htem together in the tl.

prerenders will speed up end render times unless you change something. that's why always do "render to new track" or dothis region thing.
Jim H wrote on 7/14/2006, 5:12 PM
Thanks for the tip, I've had this situation. So you take the 5 AVIs (I'm assuming uncompressed?) then put them all back on the time line and rerender the final project with audio? No loss on the second render?

I'm not familiar with the batch feature, that's a Vegas function? Easy to set up too?
TheHappyFriar wrote on 7/14/2006, 8:43 PM
if you have vegas 4 you can find a batch render script on www.vasst.com. Vegas 5 & 6 come with it under the Tools -> Scripting menu. Then you just put a checkbox next to what you want to render & choose eigther the whole project, selected areas or regions.

You can batch render to whatever render templates you want. I used NTSC DV but you can do uncompressed (I've noticed uncompressed renders a little faster to mpeg-2 in some cases) if you have the space. Since I was working with DV anyway & sony's DV codec is near perfect (IE almost no loss, if any happens at all) I had no worries.
Chienworks wrote on 7/14/2006, 8:49 PM
Jim H, if your final output is DV then intermediate DV files will be just as lossless as uncompressed. Vegas doesn't actually render when going from DV -> DV; it merely copies the frames unaltered.
kentwolf wrote on 7/15/2006, 5:21 AM
>>...thereby reducing your render time to under an hour?

That's pretty funny! :)