Help with cdrecord

[Andrew Robinson]

I'm trying to teach myself how to use mkisofs and cdrecord. I'm a little 
ahead on mkisofs, though that is like saying my verbals skills are 
better than my math skills because I can say "Ma Ma" but I cannot add 2+2.

Anyway, I wrote a script that uses mkisofs to create an iso of mp3 files 
from an m3u play list. The size of the iso file is 747200512 bytes. When 
I try burning it with gnome toaster, it refuses because it says the 
track is too large. The CDR is supposed to hold 700 MB, which according 
to my calculator equates to 786432000 bytes. So either there is overhead 
in burning the iso to disk or the CDR maker is figuring megabytes the 
way hard disk manufacturers do.

My question is this. Is there a way to determine exactly how large an 
iso file a CDR will hold? I looked at the man page for cdrecord and 
found options that will tell me about the recorder, but not the media. 
But I'm pretty sure Nero and Toast on other OS's will tell me how much 
space is available on the CDR.

I know I can systematically reduce the size of the iso and find the size 
that fits. In fact, I'll probably do that in this case while hoping to 
get an answer to this message. Still, I would prefer a deterministic way 
to accomplish this task. I'm hoping someone can provide me some guidance 
at this point.

Thanks!

Andrew Robinson