Using Bitrate calculator

[julitomg]

In advance an apologie for such a dumb, silly and stupid question...but here it goes:
I hadn´t used a bit rate calculator before since I usually make DVDs from videos shorter than one hour. But now I have to fit a two hour AVI video in a 4.7 DVD and would like to use VBR to achieve better results(less quality loss I hope) since compression will be higher than my other projects.
Like I said, I hadn´t tried it before but went to: https://www.videohelp.com/calc#calc
and typed the lenght of the video(in this case 2 Hrs, 13 mins, 5 secs), with an audio bitrate of 320 (audio is important)...the result is:
Calculated Bitrate= 4255 and DVD Max Bitrate= 9472
Now for the actual question....Does this apply only for Constant bit rate?, If I select Variable should I keep 4255 kbits/sec as the AVERAGE bitrate?Then, wht should I put as: MAXIMUM? In that same example; what values would be optimal for Average, Max and Min so the video fits the DVD and I retain most of the quality?
Sorry again and Thanks in advance...

[jimmalenko]

Yep, spot on. 4255 is for CBR or the Average if using VBR. I generally use about 50-100 less than what the calc tells me to allow for a basic menu as well. I'd use 1000 and 9000 as your min and max.


http://members.dodo.net.au/~jimmalenko/calc.htm is another bitrate calculator and it gives you recommendations for max and min, as well as GOP structure.

[julitomg]

Thanks a lot!!...great calc!!!

[slacker]

videocalc 1.1 is pretty good as well.

[dphirschler]

Why not zero for min? Isn't that the DVD spec?


Darryl

[jimmalenko]

DVD spec doesn't specify a minimum AFAIK.

[Abond]

Some players don't like less than 300 for min.