formula to estimate gigabytes

mobass1 wrote on 2/22/2008, 2:31 PM

I remember seeing a mathematical formula to convert time length in gigabytes. This would simplify estimating disc space on CD's and DVD's. Can anyone help me out?

This is a fantastic forum, everyone is so generous,
Thanx a mil....
SEM

Comments

johnmeyer wrote on 2/22/2008, 2:56 PM

It all depends on the encoding bitratte.

Bitrate Calculator

mobass1 wrote on 2/22/2008, 3:02 PM

Thanks John...I've downloaded a bitrate calculator and it works very very well. Bitrates.......theres the rub *S* . I've read that DVD's like around 8000 or so. True?
I have an hour and forty min music vid and according to the calculator, I'd get a much higher bitrate if I used 2 discs; altho it will fit onto one DVD.

Any thoughts?
Thanks again for your help.
SEM

johnmeyer wrote on 2/22/2008, 6:48 PM

Do a test burn to a re-writeable DVD using the bitrate needed to fit your 1:40 onto one disc. Use a short snippet if you don't want to spend the time to do the whole DVD. See if you can see "mosquito noise" or blockiness or other artifacts that come from using a low bitrate. Use 2-pass VBR encoding when using lower bitrates (not needed for higher bitrates above 6,000,000 to 6,500,000 bps).

So much depends on the nature of your video. With high motion, lots of dissolve transitions, smoke, fog, etc., you will need the highest bitrate possible. For pictures of the family at the holidays, or talking head shots, you can get by with 4,000,000 bps.