Constant bit rate

Luke

Luke

Well-known member
I was just in the output and compression section and wanted to know what you guys thought about Damon_C’s “Some general info on DVD capacity and bit rate” post. I want to give it a shot but had some questions for you guys first. As far as going from a VBR to a CBR he said to go with 8 mbps but the next option in Vegas up from 6mbps would be 9.8mbps. My movie is about 60min. long. Of course I can manually change it to 8 but would 9.8 give me even better quality. Here are the other settings he said would “meet the DVD spec.”

GOP size-15 frames
Field ordering-Lower Field First

Im not sure what GOP means and all I see available is a check box “Insert sequence header before every GOP”
And I thought it was supposed to be on progressive.

I thought I would come right to the Vegas brain boxes before going round with someone who may not have the program.
Thanks
 
Re: Constant bit rate

A variable bit rate makes sense when you're trying to fit a lot of video onto a disc.

A bit rate of 9.8 is theoretically better, but you assume a greater risk of your disc not playing on all players. Don't go higher than 8.

GOP = Group of Pictures.

Really, until you *really* know what you're doing, it's best to go with the Vegas/DVD Architect defaults. They'll get you to where you need to be.
 
Re: Constant bit rate

Thanks for the advice. If i change it to a CBR of 8 rather than 9.8 with a 60 min. vid is the chance of it not working on some dvd players greater than using the preset VBR. I want to give it a try because I fell like the DVXs abilities are being very poorly represented by what people are seeing by my DVDs so far. Or maybe im being to picky. I’ve followed everything by the book but the image still looks dull to me.
 
Re: Constant bit rate

Do you color-correct on an NTSC monitor or at least a TV?

If you do, what you see on the TV should be 99.9% identical to what will end up on the DVD using the presets.

A CBR of 8 with 60 minutes of vid MAY give you some disc space issues, especially if you have a 5.1 soundtrack.
 
Re: Constant bit rate

I do color-correct with an external monitor, but I only color correct what looks bad on my PC, otherwise i never see the final product on a TV untill its on DVD. Should i assume what looks good on my monitor dosn't always look good on the TV. I guess i should preview the whole thing on an external monitor before rendering.
 
Re: Constant bit rate

Yes. You should definitely assume that. There's a huge difference between what a computer displays and what a TV displays. Make sure it all looks good on the TV first.
 
Re: Constant bit rate

>the next option in Vegas up from 6mbps would be 9.8mbps<

You can type in any number you want.

Gary
 
Re: Constant bit rate

Thanks for all the help. I under estimated how important previewing on an external monitor is.
 
You must log in or register to reply here.
Back
Top