HDV to mpeg2 rendering times?

[David Stoneburner]

Doing my first big project in Vegas 9e. I have a 3.ghz quad qore Phenom running Win XP pro 32bit with 4 gigs of ram. No other background processing. Rendering showed using 1 gig of ram and 33% of the cpu. I just rendered out a 52 minute timeline to mpeg 2 and it took 10 hours. VBR, quality setting at 30, 2 pass. On the timeline I just have to increase the video levels a little and have simple lower third keys that fade in and out. Playback on my timeline is real-time in the preview window set at Half. Original footage is HDV 1080i. I'm guessing that I have my mpeg2 settings maybe too high? What is the quality vs. speed suggested setting for the Main Concept encoder? Thanks in advance for any advice.

[Seth Bloombaum]

A big part of the answer has to be "It depends. What compromises make the most sense to you, and look acceptable in your final product?"

A few signposts, some background info:

2-pass doubles the render time. Single pass probably is adequate for your content.

When resizing on a render, say, from HDV to SD for DVD, the "Best" setting in the custom render dialogs probably does more for you than 2-pass. But, even that may not be needed, depending.

Whether you've cut an extravaganza or just added a couple lower thirds makes little difference to render time. OTOH, various filters can have a big impact on render time. I remember someone posting a series of render tests with various filters, and ranking them by increasing render time, but, really, that's academic. You use the filters you have to and take the render hit (with the exception of Magic Bullet... some find the very high render hit unacceptable, and move on to other film-look packages, or, upgrade the video card to something MB can get hardware-assist out of).

MPEG2 is of a class of codecs known as "asymetric", in that they take a lot longer to encode than decode. Long render times are normal. Adjust your working style to render on breaks or overnight.

Rendering is processor-bound. I don't know where a quad-phenom stacks up for rendering, but, more recently, 8-core i7 processors are all the rage for HD editing and rendering. Since rendering is processor-bound, it benefits directly from overclocking.

Assuming everything in your PC is actually working correctly, there's one more environmental setting that can have a big impact on render times; that's the render threads parameter, which you'll find in the project properties. Increase this cautiously, perhaps starting with a 5-minute segment. You'll find it in Options | Preferences | Video. Search the Vegas Help for "threads" to get some guidance on it. Note that in case of crashes on renders, this is one of the first things to reduce!

Some less-common reasons for long rendering times:
32-bit float setting in project properties.
Inadvertant setting of track levels to less than 100% (easy to do, sometimes hard to spot).
Changes of frame rate on render.

Testing with a short segment is absolutely the best way for you to know how these various settings affect the look of your project and the render time; for you to figure out what compromises look best in the time you have available.

For the basics of rendering for DVD, I highly recommend reading Volume 1 #7 of Edward Troxel's excellent newsletters. Although written for earlier versions, the info applies to current versions.

[David Stoneburner]

Thanks for the tips. I understand MPEG rendering it's just that I'm new to using Vegas and 10 times real-time is extremely slow so I'm assuming I have something set wrong. I'll look at the threads and Ed's news letter. Thanks again.

[Edward Troxel]

There are so many variables to rendering times that it's hard to say what is correct for any particular machine. As was mentioned, 2-pass will double your time and, more than likely, is not needed - especially for a program that's less than one hour. In fact, for a program that's less than 1 hour you are probably just as well going to CBR and I would set the bitrate to 8,000,000.

By "Increase the video levels" I'm assuming that means you've added an effect to the entire project. That will slow down processing as well. Some effects are slower than others and you didn't mention which effect was used. So there's another potential bottle-neck.

[David Stoneburner]

I should have clarified a little more. The total project is 2hr 4min. It's a dance recital in 3 acts. So after calculating 1 act is 52 min and the others are a little over 30 each. I calculated for the total time for my bitrate and chose VBR 2 pass because of the over all time. I have always been under the impression that more than 30 minutes use VBR, under CBR. Anyway the only effects are the broadcast clamp, and video levels to increase the brightness for a dark stage. I'm not sure if that's the right names as I'm still learning Vegas. I've been using Liquid Edition and Premiere for a long time. Anyway, I'll mess with it some more it's just I've never seen an encode to mpeg2 that was 10 times realtime before. It just seemed really odd.

Question: What is recommended for the quality slider? I currently have it at 30. Is there a sweet spot for visual quality and speed? I am liking Vegas more each time I use it, it's just learning the in's and out's that's taking a little time.

Thanks for all your input.

[Edward Troxel]

I really don't see a need to use VBR even for a 60 minute clip. I usually set my MAX to 8,000,000 and MIN to 2,000,000 on VBR anyway and you can do up to 70 minutes at 8,000,000 so there's really no need for VBR under 70 minutes.

For 2:04, I would go ahead and use VBR but, once again, I don't really see the need for 2-pass. As for the "Quality" slider, I slide it all the way to the right which is actually 31.

[David Stoneburner]

Thanks I'll give it try.

[Jeff Harper]

Unless I'm mistaken, you're using a chip that came out three years ago. If I'm correct, that would seem to be the issue. Tweaking here and there cannot overcome hardware limitations.

I render out HDV projects with film effects to mpg2. 85 minute project takes less than thirty minutes to render out. This is the same as most others with the newer chips. Get yourself a new processor when you can afford it.

[Dale Guthormsen]

Good evening,

Jeff is right about the newer machines, several of us ran rendering tests over a year ago and the newer chips are in a different league.

That withstanding, you have what you have. I do quite a few recitals and other 2+ hour events, often with heavy color correcting and such. Depending on the exposures the broadcast filter seems heavy laden at times. You have to really load one down to have that large of rendering time.

I also prefer to work in cineform and then render to m2v or mp2, that always seems quicker than going native.

[Bruce Phung]

Originally Posted by Jeff Harper

Unless I'm mistaken, you're using a chip that came out three years ago. If I'm correct, that would seem to be the issue. Tweaking here and there cannot overcome hardware limitations.

I render out HDV projects with film effects to mpg2. 85 minute project takes less than thirty minutes to render out. This is the same as most others with the newer chips. Get yourself a new processor when you can afford it.

A+ . Render HDV to mpeg2 with my i7 920 6gigs went thru fast fast. No complaint what so ever. JUST FAST.