File size problems

blurred wrote on 11/23/2004, 1:26 PM

I'm wondering if there is something wrong with the way DVDA calculates file size during the Prepare to Burn phase. I brought in a Quicktime movie (68MB) that I had made in Vegas 4.0 for the Web. DVDA told me its size was almost 5GB and would compress to a third of that size. How did it get so big? I had no buttons yet or anything.

I've also found that when I make a movie in Vegas (80mins) it won't fit on one DVD-R. DVDA calculates that the available space is around 3.9GB. So I had to use 2 DVD-Rs. Is that normal? Do +Rs hold more?

Comments

ScottW wrote on 11/23/2004, 2:45 PM

DVDA can be really bad about making good guesses about final project size.

+R's hold the same amount as -R's 4.7GB base 10 or 4.37GB base 2. Windows shows file sizes in base 2, DVDA shows sizes in base 10.

If you use a bit rate calculator, you can determine ahead of time what bit rate you should render at (leaving a little extra for menu's, etc.) in order to fit 80 minutes on a single DVD. If DVDA was saying you only used 3.9GB then you'd have had no problem fitting it on a single DVD.

--Scott

blurred wrote on 11/23/2004, 2:58 PM

Thank you, Scott. What do base 10 and base 2 mean? Does that appear on the DVD label? Also, do you have idea why DVDA makes a 68MB file into a 4900MB in the Prepare phase and says it will compress it to a third of that size for burning? I can't understand the huge difference in file sizes.

ScottW wrote on 11/23/2004, 3:20 PM

Computers count in base 2; humans (most of us) count in base 10. Therefore when you say 1K on a computer you really mean 1024 (expressed in base 10). 1K for a human bean counter means 1000.

The DVD makers, disk drive makers, etc. all state capacities in human form because the numbers look bigger - hey, 4.7GB is bigger than 4.37GB, right? 'Member that huge 160GB drive you bought? Well, when windows formatted it I'll bet you didn't end up with 160GB from the computer perspective.

So the DVD label is going to say 4.7GB, but if you try to put anything more than 4.37GB on it (in terms that the computer uses), it won't work. Just keep in mind that DVDA is showing you numbers in human form, not computer, so when you see your project approaching 4.7GB in DVDA, you're getting near the limit. It's just that if you look at the file sizes with Windows Explorer that you need to use 4.37 as the limit.

Like I said before, DVDA cannot always figure out what the actual file size is going to be. Drag your 68MB file into Vegas and let Vegas do the render to MPEG-2 using the appropriate DVDA template, and DVDA will generally be able to make better guesses.

--Scott

blurred wrote on 11/24/2004, 9:22 AM

Scott, you are awesome! This makes total sense! Your suggestion about making the 68MB mpeg2 in Vegas is right on the money! Thank you! Thank you! I think I'm OK now.