Different file sizes on subesquent burns

tcbetka wrote on 11/9/2008, 10:26 AM
I had an interesting situation today, and I am not sure I can explain it...

In making multiple copies of this season's volleyball games for some other players' parents, one of the disks had 4.9GB volume on the first burn. Basically, I used the bitrate calculator when I rendered but made a slight error. There were 12 games, and I was able to get 4 games on each of three disks--and the other two disks ended up being about 4.2-4.4GB each. But the third ended up being 4.9GB, and I couldn't get DVDA to compress it to fit onto a 4.7GB standard DVD. No problem, I just used a double density DVD because I don't have the 2 hours that it will take to re-render at a lower bitrate.

So when I burned the first DVD it worked fine with the larger capacity disk; but then for the subsequent copies of this disk I ended up using a single density DVD because the data volume had decreased to 4.6GB? Why?

I guess the question then is, why does the media volume decrease on subsequent burns, when none of the parameters are changed? I simply chose "yes" when DVDA offered to burn another copy of the same disk--and was then able to use a single density disk on all subsequent copies.

TIA.

TB

Comments

musicvid10 wrote on 11/9/2008, 3:25 PM
On the first prepare, DVDA estimates the space usage, perhaps a bit conservatively.
On subsequent burns, DVDA knows the file size because it already exists.
That is why I always prepare the DVD to a folder first, and then burn my first disc after I (and DVDA) know the size.
tcbetka wrote on 11/9/2008, 3:34 PM
AH...makes total sense, and your suggestion is a very good one.

Thank you very much!

TB