2 pass vbr - min/avg/max bit rate effects on quality & size

[saspgmr]

I've been reading & reading but I must have missed it. Can someone please explain how the min, avg, and max bit rate settings each affect video quality and file size. I understand that the higher bit rates will generally increase both size & quality. But I'm not sure about the difference in the effect of increasing the avg rate vs. the max rate vs. the min rate.

Also, is there some correlation between these rate settings in 2-pass vbr and the quality setting in cq-vbr?

Thanks for your help.

[homerpez]

2-Pass VBR is especcially good to determine a final filesize (such as, if you want a movie to fit on a single CD). Also, I prefer using this on my SeVCD (XVCD) movies because you can sort of "cheat the system"... you can use a fairly low MIN bitrate, a low AVG bitrate, but still use a high MAX bitrate like 2300 or so (to leave room for those busy scenes that requite it). It is time consuming, and if you can, I would choose Cinemacraft Encoder to do VBR, it really is much better (and you can do 3 passes!)

CQ_VBR I don't like. I guess the theory is that it will try to keep the quality more constant along the movie, but I don't see that happening. Plus, it's VBR also, but doesn't allow you to use a high MAX threshhold, unless size doesn't matter. Really the "AVG" setting on 2-Pass is the "MAX" setting on CQ_VBR. Plus, if size DOES matter, the ambiguous "Quality" setting really doesn't help much, since it's inconsistent.