VBR vs CBR

VEGAS Pro

VBR vs CBR

Posted by Scott Francis on August 2, 2010 at 6:43 pm

Hello,

I have been using Vegas for years now (Since version 3!!) and have ALWAYS up to now use VBR when rendering for DVD. I am now looking at posts and wondering if I should change that and when….a few questions:

1) I know I should and must use VBR when rendering something over an hour that needs to fit on one 4.7 DVDR, and use a bit rate calc.
2) When under that time, is it BETTER to use CBR?
3) If so, does this make the video progressive vs interlaced?
4) Will that highest CBR rate 9,800,000 be compatible with all DVD players that can play DVDR’s?
5) To be progressive, do I need to use that setting in my project parameters?

Thanks for the help, at least up to this point me using VBR has been a priority since most all my videos are over an hour…thanks for the help!!

Regards
Scott Francis
Mind’s Eye Audio/Video Productions

Scott Francis replied 16 years ago 2 Members · 6 Replies
6 Replies

Stephen Mann
August 3, 2010 at 1:59 am

1) Is there a question here?

2) Animation and graphics sometimes play smoother with CBR.

3) Interlaced and Progressive is a completely separate topic. Not related to CBR/VBR

4) 9.8MBPS is the max spec. I never trust anything above 8MBPS. Here’s why – the player can, by spec, decode the data stream at 9.8 MBPS – if it doesn’t have to do anything else. Burned DVD’s have data errors. It’s a fact of life – a perfect duplicated (burned) DVD is extremely rare. (That’s why DVD duplication shops ask for two or more copies of your burned DVD “master”.) So, because burned DVD’s contain errors, the processor in the player has to do some error correction in addition to decoding the A/V data. If your DVD has more errors than the processor can handle in its spare time, you see a momentary pause on the screen while the player catches up.

This is also why you don’t ever want to burn a DVD at the highest data rate the hardware allows. You will have more errors.

5) See number 3.

Steve Mann
MannMade Digital Video
http://www.mmdv.com
Scott Francis
August 3, 2010 at 2:26 am

Thanks Steve…I understand progressive and interlaced…my question is how to make a DVD progressive as well. And is it a good idea to take interlaced footage (I shoot 1080i HDV) and make it progressive? Since there are a ton more pixels than 480p (standard DVD)…however with there only being 1 solid frame per 15 in HDV, will the end result suffer?

Thanks again!

Scott Francis
Mind’s Eye Audio/Video Productions
Stephen Mann
August 3, 2010 at 12:50 pm

The two are completely unrelated. If you want progressive DVD, then set your project properties to progressive.

Steve Mann
MannMade Digital Video
http://www.mmdv.com
Scott Francis
August 3, 2010 at 1:08 pm

Thanks but what about the part of the question:

…is it a good idea to take interlaced footage (I shoot 1080i HDV) and make it progressive? Since there are a ton more pixels than 480p (standard DVD)…however with there only being 1 solid frame per 15 in HDV, will the end result suffer?

Thanks
Scott

Scott Francis
Mind’s Eye Audio/Video Productions
Stephen Mann
August 3, 2010 at 2:46 pm

If you can, then shoot in progressive and keep everything up to the DVD as progressive.

But since all DVD players will do a de-interlace on the fly, why not let the player handle the interlaced video?

BTW, Encoding determines the GOP and iFrames. Interlacing has nothing to do with it.

Steve Mann
MannMade Digital Video
http://www.mmdv.com
Scott Francis
August 3, 2010 at 2:58 pm

Thanks Steve…HDV is interlaced irregardless…wasn’t sure if changing to progressive was worth it….never have before, always have done interlaced…just checking options…

Take Care
Scott

Scott Francis
Mind’s Eye Audio/Video Productions

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