TMPGEnc: two-pass VBR vs CQ discussion at VCDHelp.com
 

Here's the link...
http://forum.vcdhelp.com/viewtopic.php?t=97391

What are your actual experiences? He does make some good points, what about how CQ is 1-pass VBR?

He also says CQ doesn't compress as well as 2-pass VBR. I have gotten some exceptionally good compression out of Kwag's template with 2pvbr but my source had some compression artifacts in it already, so quality was impossible to judge.

Has anyone else experimented with this?

Re: Big x-pass VBR & CQ "flamewar" at VCDHelp
 

In a simple line: CQ is not equal to VBR.
Here's a good explanation:
http://tangentsoft.net/video/mpeg/enc-modes.html
And here:
http://www.tecoltd.com/enctest/concepts.htm

kwag

I've read the first one many times, and I don't see a huge difference in terminology, CQ varies the bit rate to keep a consistent quality, and so does VBR, except that 2-pass VBR runs through the movie once to figure out where it can safely reduce the bit rate and still maintain the quality. How does CQ know where it can chop without doing something like that?

The second link was just starting to explain x-pass VBR and it ended with "To Be Continued"

Like I said, I can't test this without some really good sources. I only have captured VHS that I have to compress, since I don't yet have enough drive space to get a pristine capture. I also don't have a DVD drive... so experiences will be appreciated! :)