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Old 23rd November 2011
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IdOp IdOp is offline
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Thanks for the nice write-up J65nko.

About the difference between 80 min audio CD and 700 MB data CD, I once looked into this with the power of google, and wrote a little summary for future reference. Here is the relevant extract of that in case anyone is curious about it:

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Consider an 80-minute audio CD. Bar spittin', the bytes of data it can hold are audio data, in the amount of (approx):

80 min * 60 s/min * 44100 samples/s * 4 bytes/sample = 846,720,000 bytes

(the final 4 is 2 tracks (L+R) * 2 bytes/track (16-bit sound samples)).

OR = 807.5 MB , M := (1024)^2

However, apparantly when writing a data CD (i.e., iso9660 filesystem) the area of a 2352-byte audio frame (1/75 sec worth) is used to only hold 2048 bytes of data, i.e., 2Kb. This gives a scale-down factor of

2048 / 2352 = 0.87075

and so the CD will only hold

0.87075 * 807.5 = 703.1 MB

This is basically the "700 MB" / "80 min" that almost all commercial CD's advertise on the label. My odd-ball Sun-Power CD-RW's say "730 MB", but I suspect this refers to mega = 10^6, where the above translates into 737.3 million bytes.
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