Things that'll kill your render speed

smhontz wrote on 6/3/2004, 5:28 AM
Having just rendered a 3 minute project in 4 hours, and wondering why it took so long, I discovered some things that will kill your render speed.

1. Opacity of a track < 100% when you don't mean to.

2. Mismatched media-project settings. I used a DIgital Juice Jumpback file as a background loop. They go into the timeline so easy, you forget that they are 320x240 15fps progressive Indeo codec and your project is 720x480 29.97 interlaced. That's a lot of conversion going on. I took the jumpback file, rendered to .AVI at the proper project settings, and replaced the one in my project with that. (Since I had looped a 5-sec file to 2 minutes, it was worth taking the time to render to an AVI file first and using that.) This cut my render from 4 hours to 2.

3. A track in 3D source alpha mode. I wasn't doing any 3D stuff but had inadvertently set my main video track in this mode. Once I put it back to source alpha (2D), my render time went from 2 hours to 20 minutes.

Comments

farss wrote on 6/3/2004, 5:52 AM
Apart from 1), Vegas is one of the few NLEs that'll let you do this, just dump anything on the TL and have it cope. Then people start to complain about render times like something is broken.
Good to see someone taking the time to sit back and analyse why it was taking so long. Whenever I've got something fairly complex going on I just render that portion to a new file, not only does it save render time down the track it's also a good backup in case I screw things up.

Bob.
Erk wrote on 6/3/2004, 8:43 AM
>1. Opacity of a track < 100% when you don't mean to.<

Yep, a real killer. I heartily recommend the "audit for event levels" script that John Meyer wrote (available on the Sundance and other sites). It looks for opacity and audio envelopes that are +/- a threshhold. Then a pop-up reminds you to check your track level sliders (very courteous, John!).

Greg
TheHappyFriar wrote on 6/3/2004, 10:44 AM
Slow CPU. :) How many people say "i have a pantium 1.4 or AMD 1.4 & it akes to long to render 3 hours to a DVD file" around here?
MJPollard wrote on 6/3/2004, 11:28 AM
Precisely why I went from a 900MHz Athlon to a 2.4GHz P4. I was tired of TMPGEnc Plus taking over 24 hours to render a 2-hour clip. :) (Yeah, I still use TMPGEnc Plus for my MPEG2 rendering, due mainly to its fine control over rendering options. Besides, I've always been an advocate of "use a tool for each job that's best suited to the task," which is also why I use Nero, not DVDA, to burn my DVDs, and VirtualVCR to do analog capturing from my AIW Radeon 8500DV.)
dvdude wrote on 6/3/2004, 12:41 PM
>"Besides, I've always been an advocate of "use a tool for each job that's best suited to the task"

But the codec used by Vegas IS a tool well suited to the task, as it's the MainConcept codec and seems to be very highly regarded. Is Tsunami significantly better than MainConcept?

Would my guess that you author in DVD-A but burn in Nero be correct? If so, to what advantage?
Chienworks wrote on 6/3/2004, 1:47 PM
I author in DVD-A 2 because it's the best tool i've got for the job. However, i burn in Nero 'cause all i can get DVD-A 2 to make is coasters. True, i haven't tried to do anything to resolve the problem, but then i don't really care to either. Nero burns faster than DVD-A 2 and it will also do a verify step if i want it to. For that matter, most of the DVDs i create have extra media & file directories which can't be done in DVD-A 2. So, in my case Nero definately is the better tool for the burning job.
MJPollard wrote on 6/3/2004, 2:16 PM
I'll have to do more experimenting with Vegas' MPEG2 output. I've stuck with TMPGEnc mainly because I've been using it for quite a while, and I know it works. I'm not adverse to trying something different, of course. :-)

And why burn in Nero instead of in DVDA2? Because again, I know that it works, and I tend to stick with what works. Plus, it's a program designed for one purpose: burning CDs and DVDs. As such, I tend to believe that it is a superior tool to use over integrated burning solutions (which I've had trouble with in the past with other applications, hence my exclusive use of Nero).

In the end, though, it all boils down to whatever works for each of us. As long as the job gets done to one's satisfaction, that's all that really counts.
Mahesh wrote on 6/3/2004, 3:12 PM
1. Opacity of a track < 100% when you don't mean to.

Any one think a lockable track sliders a good idea? e.g tick a check box and track sliders are locked
dvdude wrote on 6/4/2004, 1:00 PM
OK, I was just curious. Personally, I author and burn in DVD-A2 to DVD+RW for testing, then burn the folders into DVD+R using RecordNowDX. I've really had no problems with DVD-A2 (I did have an issue with DVD-A1 but it didn't affect the discs). I thought I'd read somewhere that RecordNow is supposed to generate unreadable DVD's with large projects (>1GB VOB's) but my last project is some 3GB and I can't find any problems with the finished discs, I've never burned a DVD coaster so maybe I'm just lucky. RecordNow simply gets me to a "click to burn" scenario quicker than DVD-A2 so I use it when duping - other than that I can't say I've noticed any differences in burn speed and/or resultant compatibility or quality.
Erk wrote on 6/4/2004, 2:14 PM
Mahesh, I'll second your request for some way to lock those track sliders. I almost never (intentionally) make adjustments at that level, but I do sometimes bump them or something.

G
Lajko wrote on 6/5/2004, 1:58 PM
I question the Jump Backs. I use their jumpbacks and editors toolkits in about every project. Tthey are full resolution at 29.9fps.As some are a still image sequence, the frame rate is whatever your project happens to be. The samples from the index DVD are at 320x240. Some at 30fps and some at 15fps progressive.

How are you using them? It seems you are using the samples contained in the index rather than the real jumpback from the DVD. Those are often 720x576 and their "Juicer" program would resize them to 480. However, I drop in that size then crop to 480.

Maybe you can elaborate on how you are using them, wnat DVD you get the loop from and specifically which loop from which set you are using.
smhontz wrote on 6/5/2004, 3:37 PM
Ours is an older library that came on a bunch of CDs (not DVD). We used the animated elements disk, and everything on it is 320x240. I believe it's original intent was to be used with PowerPoint. The clips we used were 009, 019, 036, and 039.
DavidPJ wrote on 6/16/2004, 7:04 AM
Just discovered how important it is to make sure track opacity is at 100% when it needs to be. I rendered a 57 minute project several times in best mode and it took about 10 hours.

Made a few edits, discovered 2 tracks had opacity levels just under 100% and changed both to 100%. Also disabled Norton Antivirus auto-protect. I don't know how much disabling Norton Antivirus helped, but my render time went down to 4 hours!

Thanks john meyer for the script, I'll be using it in the future.
johnmeyer wrote on 6/16/2004, 8:01 AM
Thanks john meyer for the script, I'll be using it in the future.

You are welcome.

Sony, I hope you consider including various "auditing" functions in future versions of Vegas. I have written scripts to detect the opacity problems mentioned in this thread, as well as the accidental short gaps or overlaps between events (something that is all too easy to do in Vegas) that have been mentioned in many other threads. Other things I would like to see:

A diagramatic view of the video and audio paths through all the busses, with highlights whenever something is being done to the audio or video at that stage.

A warning whenever a known render hog is being applied (such as supersampling) for more than a certain percentage of the project.

Highlight any event that will require rendering, and provide a button that will bring up a menu that will tell you why that event needs to be rendered, and what is going to be done with it. If I am doing a project that is mostly cuts, and I then see all my events highlighted in yellow, I can immediately know that something isn't right.

I would envision that this "auditing" would be implemented in much the same manner as you already do in DVD Architect, where you provide various alerts and warnings just after I click on the "Prepare" button.

I would also suggest new sections in the manual entitled: "Rendering for Quality," and "Rendering for Speed." Many threads in this forum concern these amazingly important tradeoffs, and there is nothing the manual that explicitly addresses the issue.
cacher wrote on 6/16/2004, 10:05 AM
Custom compositing is also a render killer in some circumstances, see this post.