MPEG-2 takes so LONG

Rogueone wrote on 11/4/2003, 11:50 AM
I'm sure this has been addressed before, but is there any way to increase the speed that Vegas renders to a DVD MPEG-2 format? The other day I did a real short clip; it's like a 4 minute segment. All I added was 2 audio tracks, some sound effects. It took Vegas 54 minutes to render the entire thing. I thought about Pre-rendering it, but every time I try to pre-render a project it doesn't work. Does anyone have any suggestions on how to decrease the time involved in rendering??

Cheers,
Rogue One

Comments

BillyBoy wrote on 11/4/2003, 12:08 PM
Short answer: Get a system with a faster CPU.

Rendering times are relative to the complexity of the project, what filters if any are applied, some are VERY slow, like Median, also the horsepower of your system, number of tracks, etc., all impact on rendering times. The truth is there is no ready answer as to 'how long' it should take to render. There are simply too many variables.

Some rendering tasks are not as obvious as others as far as speeding them up. For example a few things you can do that can GREATLY reduce render times:

1. Reboot first! The longer the project, the more impact. Why? Not sure exactly other then rebooting forces Windows to reclaim system resources. Doing that can reduce rendering times by 10% or more. That CAN be a big deal for longer projects. Did some real world tests way back almost two years ago with some other forum members. Even though they had a FASTER system than I did, I beat them rendering the same small test project only because I rebooted, and they didn't.

2. Be sure the drive you're rendering to is set to DMA, is defagged, isn't your system drive.

3. Avoid having Vegas repeat itself. If you're making multiple versions of your project, one as a AVI and also a MPEG version do the AVI first. Once finished, take the rendered file, START A NEW PROJECT using it as the source. Vegas should fly along doing the MPEG render. If you have a fast system, you can get close to real time or even a little faster. Why? Because all the work Vegas needed to do is already contained and 'rendered out' in the just rendered AVI rendering. By using it as source all Vegas has to do in the second pass is convert from AVI to MPEG-2 which it is capable of doing very fast. If on the other hand you just tell Vegas to render as a MPEG still using the original project it will do all the caculations all over again and all for nothing!
Rogueone wrote on 11/4/2003, 1:50 PM
Thanx for the info there, BillyBoy. I've got a AMD Athlon 2500+ Barton core, so I just thought perhaps it should render faster. I will have to try a reboot before I render. Currently, my primary drive (Maxtor 120 GB) is two partitions; I always used the secondary partition as my 'video drive'. I've just installed another 80 GB drive, and this be totally for video only. Both are 7200 RPM.
The AVI first concept sounds good, but that would take a lot of HD space, wouldn't it? Uncompressed AVI is huge!
Anyways, thanks again for all your helpful tips on it!

Rogue One
Liam_Vegas wrote on 11/4/2003, 1:56 PM
Not uncompressed AVI... just the regular DV AVI version... still takes up 13GB per hour... but not the same as uncrompressed.

Although 54 minutes to render a 4 minute clip on an AMD 2500+ does sound excessive to me... I can't imagine what is taking so long.

Certainly rendering back to the same drive (with the partition setup you describe) would impact the rendering time. That second drive may make all the difference

-Liam
BillyBoy wrote on 11/4/2003, 2:13 PM
I agree with Lima. If you can, avoid rendering to your root or system drive. It doesn't matter how many partitions it is, it DOES matter that its a seperate physical drive. The reason being its on a seperate IDE channel. Not really so much a difference for rendering, but it can impact on 'printing to tape' and/or with capture. Each system is different. I also agree 54 minutes seems slow. A 2500 Ghz CPU regardless if Intel or AMD for a typical Vegas project (if there is such a thing) should usually have a render ratio of roughly 7 to 1 or maybe up to 8 to 1 unless you doing something that's very processing intensive.
Rogueone wrote on 11/4/2003, 2:25 PM
Yeah, now I can't wait to try a project with a separate drive. Hopefully that will speed things up somewhat.
I am connected to a home network, although I usually disconnect the Cat5 cable when I render. I didn't disconnect it for the 4 minute clip; I figured it was short enough it didn't need to. Maybe I should always disconnect it in the future.
Would divers affect the system? I usually try to keep up with driver updates, especially with the video card. My sound drivers are probably out of date, though. I've got to apply the newest ones for that.

Rogue One
seeker wrote on 11/4/2003, 11:31 PM
BillyBoy,

Your answer is excellent, and to the point. With regard to your recommendation #3, would you recommend rendering to AVI even if you are not making multiple versions of the project? Presumably that would be using the compression of Vegas' proprietary DV codec. My attempts to use Vegas AVI renders in other software, like for example Corel Painter 8, have failed unless I elect to render them as uncompressed AVIs. Apparently other programs cannot access the Vegas DV codec.

With respect to MPEG encoding, I notice that Main Concept markets a separate standalone MPEG-2 encoder, which presumably is kept more "up to date" than their "subcontracted" MPEG encoders that are included in products like Vegas and Premiere. The Main Concept standalone encoder now offers two-pass encoding. Do you think it would produce higher quality MPEG encoding than the Vegas version of the Main Concept encoder?

-- seeker --
kentwolf wrote on 11/4/2003, 11:38 PM
>>...I notice that Main Concept markets a separate standalone MPEG-2 encoder...

I have it (v1.4) and use it all the time. It works excellent... Excellent quality...faster-than-real-time render. Even allows you to capture in MPG2, if you have a need for that. That's how fast it is.

The 2 pass doesn't look better to me, but I guess if you have the eye for it, it might. It's a pretty undiscernable difference, in my opinion. It uses 1 pass to analyze the footage, then the other pass to actually do it. It take twice as long as 1 pass.

To me, it is worth the expense for the hours cut of rendering. Single pass encoding looks terrific. Does batch coding too.

There is a demo available.
BillyBoy wrote on 11/4/2003, 11:57 PM
Hi Seeker...

With regards to #3, no, not necessary. I do simply because I ALWAYS make a DV AVI copy for archavial purposes on top of backing up on a hard drive and burning a DVD. So it works for me. As far as other applications not being able to open a Vegas generated AVI that usually due to the type of AVI Vegas generates.

The latest and greatest MC encoder is always going to be a step or two ahead of the included Vegas version. Vegas usually catches up in the next release plus you're getting the tuned version which should perform better. You can if you want buy the latest MC encoder, but I don't really see any reason too.

Two-pass encoding is probably somewhat over rated. As I understand it the first pass just scans the file and gets a better understanding of which sections would benefit from higher bitrates. Using the default included MPEG-2 encoder used at default settings it uses variable birrate and does it on the fly. Maybe a little less accurate, but mostly all the 1st pass on a 2 pass encoding is doing is prolonging the render times. Generally the results aren't that much better if at all to make it worth the bother.
Rogueone wrote on 11/5/2003, 2:15 PM
Could source files be an issue? I record my movies with MPEG-1, because I can get good quality at fairly good data sizes. Could my MPEG-1 encoding be causing a hassle for Vegas; making it take longer to render?

Rogue One
farss wrote on 11/5/2003, 2:43 PM
Ah absolutely!
Unless you've converted the mpeg1 to an avi first then VV is first having to decode the mpeg1 stream, apply whatever effects and then encode back to mpeg-2.

This will slow things down no end and it's probably not previewing too well either on the timeline.
Rogueone wrote on 11/5/2003, 2:55 PM
Previewing is fine, so that's what I couldn't figure out. So what is the recommended format to work with? Record sources as uncompressed AVI? Or is there something else that works as well, without hogging hard drive space?

Rogue One
farss wrote on 11/5/2003, 3:01 PM
No real advantage in using uncompressed, just stick to DV. Main use for uncompressed is some external programs require it. Also if you're rendering out and then plan to work on that output, doing that can avoid compression / decompression losses however these only come into play when fx are applied plus a few compress/decompressions are not really noticeable particularly with the VV codec.
Laurence wrote on 11/6/2003, 9:55 PM
I've noticed lately that the amount of free space on your hard drive makes an absolutely HUGE difference in rendering times. If your hard disc is close to full, it can easily take 4 or 5 times longer to render. I don't know why exactly, but I've experienced this firsthand.

Laurence Kingston