How did someone fit 740MB on a 700MB CD-R?

Factual Questions
1

I’ve come across a situation that is making me scratch my head and say, “Huh?”

I’ve got an 80-minute, 700MB CD-R filled to the brim (and more, as you’ll see) with music. (The disc came from a friend who’s in the band that created the music, so it’s legit).

Now, when I’ve tried to make a copy of this CD-R, I cannot fit the whole thing onto another 80-minute, 700MB CD-R disc.

Why not? Well, it’s because after I import (extract, rip) the files to my computer, it turns out that the sum of the audio files exceed 700MB … 740.5MB to be exact.

Why is this? How did the band burn a 700MB-capacity CD-R with 740.5MB of audio files? (I can’t ask them, 'cause they’re on a tour right now.)

I’ve extracted the files in both AIFF and WAV format, and I get the same exact file sizes. When I check the properties of the original CD-R as it sits in my computer drive, my computer comes back with that same number: 740.5MB of data on a 700MB disc!

For the record, I used iTunes on a Mac to import the files. Strangely enough, iTunes did perform a burn of a 700MB CD-R, but the 23rd and final track (a 2:10 song) track was cut off after five seconds.

I’m surprised that iTunes would attempt to burn a CD-R, “knowing” that I was attempting to record files that exceeded the capacity of the disc. (I would have at least expected a warning!)

BTW, the total duration of the songs is 72 minutes … eight minutes under the 80 minute limit of the CD-R.

Can anyone figure out what’s going on?

2

They may be overburning the disk by writing on the part of the CD that is normally left blank. It’s a bit risky (the disk or the writer could be damaged), and the CD won’t always work with all audio players, but it is occasionally useful.

3

This is from the CD-R Faq:

"Incidentally, don’t get confused when you discover you have 700MB of audio extracted from a CD that only holds 650MB. Audio sectors use 2352 bytes per sector, while standard CD-ROM data uses 2048 (the rest is for error correction). You can put roughly 747MB of audio onto a disc that only holds 650MB of data. "

http://www.cdrfaq.org/faq03.html#S3-8
So that might explain it

4

I found this when I asked a Teradata consultant I know to burn a copy of a demo CD as he had done for previous versions. He found he couldn’t but fortunately I was able to order one from the factory. Unfortunately one I can’t make a backup copy of.

5

Thanks for the replies, everyone.

So, does anyone know if iTunes can be used to overburn CD-Rs?

6
      • Well the quickest way to find out is just go crazy and try overburning a disk and see what happens. How far you can overburn depends on what hardware, software and media you are using.
        …
        Subject: [3-8-3] How can I exceed the stated disc capacity (“overburning”)? --> http://www.cdrfaq.org/faq03.html#S3-8-3
  • There are some very low-level “open-source/format-hacker-style” programs out there for forcing CD-R drives to do strange things to CD-R’s, but I dunno how many are available for Mac…
    ~
7

Spiff , itunes can’t. Actually itunes and Mac OS X’s built-in burning functions actually seems to allow less burning space than other programs. Roxio or other 3-rd party softwares should do the trick.