[From www.vcdhelp.com]
How come that I can fit 740 MB on a 74 min CD or 800 MB on a 80 min CD?
A VCD,XVCD,XSVCD or SVCD are burned in mode 2 form 2 instead of ordinary data mode where you fit 650 MB on a 74 min CD. The mode2 form2 has less error correction than data mode and therefore you can store more video.
VCD,SVCD - Mode2 Form2 = 2324 bytes/sector = 333,000 * 2324 = about 738 MB on a 74 min CD.
Data - Mode1 = 2048 bytes/sector = 333,000 *2048 = about 650 MB on 74 min CD.
(a CD has 75 sectors/s = 74 min CD * 60 * 75 = 333000)
If capacity = 79:57, then:
75 * (79 * 60 + 57) = 359,775 sectors
in data mode: 359,775 * 2048 = 736,819,200 bytes = 702.68MB
in Mode2 Form2: 359,775 * 2324 = 836,117,100 bytes = 797.38MB
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