Vegas Render Quality tips?

Robert Eldon

Robert Eldon

Well-known member
I've searched the forum and found bits and pieces of the information that I am looking for.

I'm wondering what some tips might be for rendering the best quality for the web and for DVD?

I'm trying to understand Video bit rates. I've read that using a CBR of 8,000,000 renders a great quality video. I tried a test and rendered a .mp4 (MainConcept AVC/AAC) using the default settings in my Vegas 8 set up. Using custom, I see that the bit rate is set to VBR with a Maximum of 768,000 bps and Average 512,000 bps.

I rendered a video that didn't look too bad and was 27.1 MB. Then, I changed the settings for bit rate to CBR and used 2,000,000 bps, the size was 91.0 MB. The quality of the .mp4 rendered with the CBR looked a lot better and sharper.

So, my questions are what is the difference between CBR and VBR? What is the 'Two-pass' option used for?

For DVD's, My Mpeg-2 settings for bit rate are different. The default is VBR with the Maximum set to 9,500,000 and Average at 6,000,000.

I've also heard about something about setting the Opacity in the time line of a Vegas project to 50% and having two video tracks. What is that about?

Bottom line, I want to get the best video quality (for DVD) that is possible out of my Vegas projects.

Thanks.
 
For DVD you need to use MPEG2, not mp4. For duration up to one hour (approx) 8Mbps CBR is the way to go. If you have a longer duration to fit on the DVD, you will need to drop the bitrate and switch to VBR which will use less bits where there is not so much detail in the shot.

2 pass VBR gives better results (than single pass) because the first pass allows it to scam through the video and see where best to allocate the available bandwidth. Of course the downside is that it takes longer to encode.

The opacity thing I've only heard of in conjunction with getting smooth slow motion. Not aware of any connection to DVD encoding.

The other think that might affect your DVD quality is your project settings, but you didn't mention what format your footage is in.
 
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For DVD, the DVD Architect templates under MPEG-2 are already optimized for best results -- use those.

But keep in mind that you'll have to render the audio separately as AC-3 or as WAV (PCM). Save them as the same file name in the same folder, and DVDA will match them up automatically.
 
Jaegersing,

I alway use Mpeg-2 for DVD's. I was testing the .mp4 for web distribution and for the DVXuser fest's. I wasn't clear on that. Thanks for the info on the bit rates. I think I understand a little better now.

And for DVD's right now, I primarily have short movies, so the available space on the DVD is not a problem. I have seen the 8Mbps comment before and will try that out. Thanks for the education on the 2 pass VBR.

Do you know if when using the VBR, and there's enough space, does it use the Average bps or the Maximum bps? I think I'll try the 8Mbps CBR.

David,

Thanks for the heads up on rendering for Mpeg-2. I think I have that process down pretty well (from your previous assistance). I set the loop region, render the Mpeg-2, then render the AC-3 separately.

I have a question regarding the AC-3 render. There are two options (using Vegas 8.0b). Dolby Digital AC-3 Pro and Dolby Digital AC-3 Studio. What's the difference and which one should be used?

Thanks for your reply!
 
You don't have to render audio separately do you? I always keep it with the video and I've never had any problems with Architect because of it. Is this lower quality?
 
Drew Ott said:
You don't have to render audio separately do you? I always keep it with the video and I've never had any problems with Architect because of it. Is this lower quality?
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My understanding is that DVDA has to demux the audio from the mpeg if it's included. This can reduce the audio quality and it slows the rendering time. It's actually very fast when you render the Mpeg-2 and AC-3 separately. As long as the file name is the same, DVDA will put them together.

David Jimerson has mentioned this a number of times.
 
RobertE said:
Do you know if when using the VBR, and there's enough space, does it use the Average bps or the Maximum bps? I think I'll try the 8Mbps CBR.
Click to expand...


Hi Robert. The encoder doesn't know how much disc space you have, so I expect it will use average where it can, and use more (or less) bits where necessary.

Regarding the audio, if disc space is not tight, you will get the best results using wav because it is uncompressed. AC3 is great for longer programmes, but I wouldn't use it unless I have to because most of my videos are based on music tracks and I prefer not to compress unnecessarily.
 
Whenever I render as MPEG2, the playback (on my computer using Windows Movie Player) is choppy. Is that because it's designed for Architect and would play fine once burned on a DVD or is this a sign that something is wrong?
 
Jason K said:
Whenever I render as MPEG2, the playback (on my computer using Windows Movie Player) is choppy. Is that because it's designed for Architect and would play fine once burned on a DVD or is this a sign that something is wrong?
Click to expand...

Unless you selected a very high bitrate for the encoding, it's not likely to be a problem with the MPEG2 file. The only playback problems I would expect to see on a PC are interlacing artifacts, which will not be present when you play back on a DVD player.

Is your windows media player a recent version? Earlier media players did not support MPEG2 well.
 
Gentlemen:

DVDA has excellent templates for NTSC 60i and 24p in 4:3 mode and widescreen.

You must render audio in a separate file. The DVD recording spec does not support Mpeg (MP3) audio. You can use WAV/PCM (uncompressed) or AC 3 audio in the spec.

Bit rates in exceess of 8.1 mbs are of little value and can cause PC DVD players to freeze or crash. Desktop sets may not play or do so in an unpredictable manner.

S Cannon
 
jaegersing said:
The only playback problems I would expect to see on a PC are interlacing artifacts, which will not be present when you play back on a DVD player.
Click to expand...

Ah, that's it and thanks a lot.

Now as a dumb question, let me confirm what I've gathered from recent forum reading.

For computer playback, .avi is your best quality option. And for making DVDs, the DVD Architect MPEG2 templates are best. Do I understand this all correctly?

And lastly, when assembling a large project composed of various pre-edited scenes, is it best to render those scenes as .avis then the assembled project as a MPEG2 for an actual DVD? Or is there a superior uncompressed file type to render these individual scenes?
 
Jason K said:
For computer playback, .avi is your best quality option. And for making DVDs, the DVD Architect MPEG2 templates are best. Do I understand this all correctly?
Click to expand...

Hi Jason. AVI is just a wrapper that tells the media player what is inside, it doesn't mean anything in terms of quality. That is governed by the codec you use when you render. The best quality is uncompressed (i.e. no codec), but the file sizes are huge and may not play smoothly if the hard disk speed is not up to it. WMV or DIVX will give good quality results with much smaller files, and will also allow you to keep your project as HD if your footage was HD to begin with.

The DVDA templates are really just a good starting point. If you need to fit more material onto a disc you can adjust the settings accordingly.

Jason K said:
And lastly, when assembling a large project composed of various pre-edited scenes, is it best to render those scenes as .avis then the assembled project as a MPEG2 for an actual DVD? Or is there a superior uncompressed file type to render these individual scenes?
Click to expand...

You can bring sub-projects onto the Vegas timeline which avoids any unnecessary compression stages. If you really must render the sub-projects, you can use a lossless codec like Lagarith or an intermediary codec like Cineform.
 
David Jimerson said:
For DVD, the DVD Architect templates under MPEG-2 are already optimized for best results -- use those.

But keep in mind that you'll have to render the audio separately as AC-3 or as WAV (PCM). Save them as the same file name in the same folder, and DVDA will match them up automatically.
Click to expand...

Jaegersing, heep in mind, however, that the default is only set up to render with with ONE PASS. You may want to check TWO PASS for better quality.

But yes, what David said. The default template is optimized for good results.
 
Hi Paul. What you say is correct, but since the default settings are pretty high bitrate, for me the results are easily good enough. I find 2 pass is only really necessary at lower bitrates where the encoder has a tougher job to do. Actually I usually use Procoder rather than Mainconcept if I have to go below about 6Mbps, because I think it does a better job.
 
I use 2 pass regardless, but honestly, I'm not sure how much better that will make the image at such a high bit-rate. I haven't tested it. I just do it regardless. Couldn't hurt, right?
 
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