How in the heck do u burn a 731MB ISO file if cdr's only hold 700MB?

Discussion in 'CD-R' started by tgg, Mar 7, 2003.

  1. tgg

    tgg Member

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    How in the heck do u burn a 731MB ISO file if cdr's only hold 700MB?
     
  2. HaroldW

    HaroldW Guest

    If the ISO is a VCD or SVCD image it should burn fine:

    The capacity listed on the labeling of CD's is "mode-1" (data) capacity. A 80 minute CD holds approx 700 mb "mode-1". VCDs and SVCDs are recorded "mode-2" That same 80 minute CD holds approx 800 mb when recorded "mode-2". Therefore, if your 730 mb file is a VCD or SVCD compliant MPEG file you should be able to fit it on an 80 minute CD with "room to spare".

    I burn VCDs, CVDs and SVCDs all the time from 800 mb compliant files, onto 80 minute CDs.
     
  3. aldaco12

    aldaco12 Active member

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    Not exactly. The '700 MB' is the 'actual data' capacity, that is 2048 bytes for sector.

    74 min CD =333,000 sectors, 80 min CD = 360,000 sectors (75 sector/sec is the 1X read speed, historically from the speed of audio players).

    An image is extracted RAW (actual data + header+error correction and detection codes, and therefore its size is 2352 bytes/sector).

    When you burn an image (as opposed to file burning) you burn take into account all the sector bytes. Therefore, for image burning only (and this applies to ALL RAW images, extracted from MODE1, MODE2 Form1, MODE2 Form 2 or AUDIO sectors), the maximum size (as posted in many threads is):

    74 min CD = 333,000 * 2352 bytes = 747 MB
    80 min CD = 360,000 * 2352 bytes = 808 MB

    for DATA (MODE1 or MODE2 Form 1) purposes, instead, you have more famliar numbers:

    74 min CD = 333,000 * 2048 bytes = 653 MB
    80 min CD = 360,000 * 2048 bytes = 700 MB

    for VIDEO DATA CDs (MODE2 Form2, the movie data on VCDs for instance) you have to multiply the numbers above for 2324 bytes instead of 2048 in order to have the maximum capacity.

    (if you notice, this is the same when you burn AUDIO, which you always burn 2352 bytes/sector. You know that uncompressed audio needs 10.1 MB CD space per minute?)
     
    Last edited: Mar 7, 2003

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