Mastering DVD?

braw

braw

Well-known member
I have noticed that when rendering my footage in Vegas as an MPEG, it seems to loose a little quality and becomes slightly grainier and I loose a little lattitude or it seems to crush the blacks. I'm sure this is to be the case since it's compressing it, but isn't the original footage already NTSC compliant? I was wondering if anyone has any tips or preferred settings to maximize the quality when mastered for DVD.
 
Re: Mastering DVD?

I'm not using vegas. (I'm using adobe encore dvd). But i've found a couple techniques that help with my work.

How long of footage are you trying to fit on a dvd?

If I'm making a dvd that's got footage of less than an hour, I usually will go with the highest bitrate possible. I duno if vegas lets you control your mpeg2 output options but here's what I will try to use:

9.6Mb CBR 2-Pass

That will give you some decent dvd footage. If your footage is longer than an hour, adjust the bit rate lower (only as low as you need to fit all your footage on the disc.). You can try VBR instead of CBR (Variable instead of constant bitrate), and always use 2-pass.

best of luck.
 
Re: Mastering DVD?

I don't use Vegas either but all the authoring programs basically do the same thing. Here is a universal bit rate calculatorhttp://www.videohelp.com/calc.htm

Also, in the program I have it recommends CBR (Constant bit-rate) for dvds shorter than 15 minutes, and VBR (Variable Bit Rate) for dvds longer than 15 minutes.

Also make sure GOP (Group of Pictures) is set at 15.

Hope this helps.
 
Re: Mastering DVD?

just a note , but ..you shouldnt relly go above an average of 7.4 mb per sec for DVD playback if you want it to play properly on all players. alot of players will choke on a sustained higher bitrate.
 
Re: Mastering DVD?

I figured bitrate was pretty important, but even at the highest bitrate, I seem to lose some dynamic range. Is this unavoidable?
 
Re: Mastering DVD?

How are you judging this loss of dynamic range? Are you viewing on an NTSC monitor (your TV) or your computer monitor. Your TV will automatically be more contrasty than a Computer screen. You can use the color correction tools in vegas to preview how contrasty your footage will look on a computer screen.
 
Re: Mastering DVD?

I am looking at the raw capture of a scene vs. the compressed mpeg version on my computer monitor. I'm not sure if my terminology is correct here as far as dynamic range. I'm speaking of the blacks being crushed. Shadow information is lossed. I just wonder where the loss is occuring. I know the raw .avi's are freaking huge in file size compared to the mpeg versions, so that's a contributor...I'm wondering if that's THE reason there is a difference.

I appreciate all your help guys.
 
Re: Mastering DVD?

your terminology is correct. The loss of shadow/highlight information has to do with dynamic range. It is hard to say without seeing a grab, but technically yes, shadow information will most likely be compromised, as with any colors that are close to others, again depending on how much compression. This is going from a 25Mbps data stream to one that is less than 1/3 of that. You have to loose data somewhere, so the mpeg encoder takes it out of places that will show the least.
 
Re: Mastering DVD?

is there a way to set a higher bitrate just on that one section of the encode?

I author and encode in Spruce. Never had problems with 9.6 2-pass vbr encodes.

However, I do notice on DVD Studio Pro, the softare will wig out on any bitrate higher than 8.0 Not sure if Vegas acts the same way though, nevr used it.
 
Re: Mastering DVD?

The defaults for Vegas seem to be 8Mb max, 6Mb target, and I think 192Kb for minimum. I did try setting the max to I believe 9.8Mb. Should I adjust all of them up to a higher setting?

I did see a noticeable difference when I cranked them all up, but I suppose the purpose is to optimize for smallest size with tolerable image. I guess I'm looking for bitrate settings you guys use. ???
 
Re: Mastering DVD?

like I said, I never used Vegas, so I don't know if it'll wig out at higher bitrates. But if the footage is less than 45min or an hour, then try cranking it to 9.6 max. Target the same or 9.0. Min at 8.6. You really don't want to do anything higher than 9.6.
 
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