Bitrates: How does it do Size Prediction?

[Shibblet]

I just used CQ / CalcuMatic for the first time. Works great on getting the right CQ Value, however... it varies from movie to movie.

I did a test on 3 different DVD's.
120min KVCD TMPEG Template 352x240

First was "Best of Mike Meyers - Saturday Night Live" 83 mins.
Inverse Telecine / 23.976 fps. 1.33:1 Aspect
CQ Matic made the file too big. About 850megs.

2nd "Lord of the Rings - Extended DVD Edition 1st Disc" 104 mins.
Film / 23.976 fps. 2.35:1 Aspect
CQ Matic made the file too big. About 900megs.

3rd "Fight Club" 139 mins.
Film / 23.976 fps. 2:35:1 Aspect
CQ Matic made the file WAY too big. Almost 1500megs.

So, I guess, after reading in the forums, everyone seems to love this program, and it works wonders for them. What am I doing wrong? And does someone have a guide?

[Dialhot]

Your third attempt is very strange. CQMatic has accuracy problems (due to the way CQ is managed by tmpgenc in fact : the curve is not linear that prevents any 100% accurate prediction) but not so much !

A good policy is to use an audio bitrate for the prediction a little higher than the one you really plan to use (160 insteed of 128 for instance).

[dongxu]

CQMatic is a good tool and use it often. I alwasy take of 0.2 of the predicted CQ and the size is 10mb less or more, then i do something with the audio.