What does 80 mode 1/mode 2 cd mean in FFmpegx?

[pants]

when you have the option on the first tab to select how many minutes your clip is and select the cd type, what does that mean? cause one selections gives you one bit rate and another give a different one.


thanks

pants

[incredible]

Hi here's the answer (taken from the FAQs Page of 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.

80 min CD
VCD/SVCD/XVCD mode
Mode2 Form2 = 2324 bytes/sector = 360 000 * 2324 = about 800 MB on a 80 min CD.
Data mode
Mode1 Form1 = 2048 bytes/sector = 360 000 * 2048 = about 700 MB on a 80 min CD.

(a 80min CD has 75 sectors/s = 80min CD * 60 * 75 = 360000)


74 min CD
VCD/SVCD/XVCD mode
Mode2 Form2 = 2324 bytes/sector = 333 000 * 2324 = about 740 MB on a 74 min CD.
Data mode
Mode1 Form1 = 2048 bytes/sector = 333 000 * 2048 = about 650 MB on a 74 min CD.

(a 74min CD has 75 sectors/s = 74min CD * 60 * 75 = 333000)