How much music really fits on a CD?

randycat99randycat99
Posted:
in General Discussion edited September 2014
Sorry if this has been discussed somewhere already...but how is it possible to burn 842 MB of AIFF tracks on a 700 MB CDR? I have no explanation for this, but iTunes is making a go for it right here at this very moment. How is this possible?



I've been curious about this for some time, as I've noticed past CD's track contents I've burned have gone past 700 MB and no problems. So I wondered what is the upper limit then and of all the wasted space on past CD's I've burned where I was conscientious to make arrangements that were below 700 MB (and there were times were I really wanted to put on that extra track...).

Comments

  • Reply 1 of 10
    ghost_user_nameghost_user_name Posts: 22,667member
    You need to see what the CD media is rated for in terms of minutes, not megabytes. Basically, I think the largest CDs out there run 74 minutes and 25 seconds, but I could be mistaken.



    This link may give you a more in-depth explanation of the CD Audio Format, which, I believe, follows the Red Book specifications...



    <a href="http://www.audiovideo101.com/dictionary/sampling-rate.asp"; target="_blank">http://www.audiovideo101.com/dictionary/sampling-rate.asp</a>;
  • Reply 2 of 10
    der kopfder kopf Posts: 2,275member
    well, I only buy ceedees with 80 minutes capacity, so I know for a fact that you are mistaken, M3DJack.



    As far as I know, there are different requirements between data vs. audio cds (in that data makes room for more security and reliability measures, thus leaving somewhat less room for actual data).



    I think therefore most cd-rs have two indications on their cover, of the type:



    650 MB or 700 MB

    74 min 80 min
  • Reply 3 of 10
    ast3r3xast3r3x Posts: 5,012member
    if you are burning mp3z, regaurdless of the size...you can only fit 79:59 onto a cd...although i dont think i ever tried 80....hmmmmm
  • Reply 4 of 10
    matsumatsu Posts: 6,558member
    There are two other sizes out there (but I don't know if they support data or are audio only, iThink only the latter). They are, wait for it, CDR-90 and CDR-99 (800 and 880, or something like that).



    The better standalone models support these sizes (but I don't know if Apple's internal burners supprt them) Furthermore, you can overburn a CD, yeilding slightly over 100 minutes to a disc. Do Apple's standard opticals support CD overburning? BTW, is overburning only for audio discs?



    All that being said, I think the discs are rather hard to find and a bit more expensive than CDR74/80.
  • Reply 5 of 10
    eskimoeskimo Posts: 474member
    There are three ways to make CDs hold more information than the standard 74 minutes. (which btw is actually the standardized maximum for CD-R).



    1) Decrease the pitch thereby increasing the density at which the information is written. This is what 80min CDs allow. There is tolerance built in to the 74 minute standard so you can usually get by at 80 minutes with few reliability issues. The CDR90 and CDR99 formats push this to the limits and there are few drives that can reliably read and/or write them.



    2) Burn beyond the standard track limits. This means physically record your data outside the region specified by the CD-R standards. This is referred to as "overburn" and can lead to physical damage of your drives laser assembly if you aren't careful. Also overburned disks are not always reliably read by CD-ROMs as they have to search for information stored beyond specifications.



    3) Eliminate triple redundancy and/or error checking. Doing this has allowed enthusiasts to burn what is known as XCD format data CDs. Any errors present during burn will render the data corrupt. But it is possible to get up to 800MB on a 700MB disk.
  • Reply 6 of 10
    randycat99randycat99 Posts: 1,919member
    These are just plain ole 700 MB CDR's I am using (or maybe it wasn't, because this particular disc is one that someone gave me, so who knows?). Turns out in the end, I burned a 790 MB disc containing 78 min of music. Probably there is a bit more space that could have been used on the disc, but the 50 MB or so of the next track was just too much to fit there. I'll post back if there are any problems later on trying to access the final tracks on my car CD player...



    I guess this does make sense given the typical 700 MB/80 min specification. Intuitively, I would have thought the 700 MB limit is a 700 MB limit, but who's gonna turn down extra MB's, right?



    [ 10-29-2002: Message edited by: Randycat99 ]</p>
  • Reply 7 of 10
    formerlurkerformerlurker Posts: 2,686member
    Ignore the MBs and concentrate on keeping the total time below 79:59



    works for both iTunes and Toast



    My theory is the MB is off because of cluster size.
  • Reply 8 of 10
    witch2088witch2088 Posts: 1member
    Hi, dug up old thread, but after burning 700.1 mb I was like w000t! Anyways, 5 years later we have the magic of http://en.wikipedia.org/wiki/CD-R ... The limit here mentions 736,966,656 bytes or commonly 702mb, which is 2 over the 700mb "advertised" size of 700mb/80min CDRs.
  • Reply 9 of 10
    shetlineshetline Posts: 4,695member
    Quote:
    Originally Posted by Randycat99 View Post


    Sorry if this has been discussed somewhere already...but how is it possible to burn 842 MB of AIFF tracks on a 700 MB CDR? I have no explanation for this, but iTunes is making a go for it right here at this very moment. How is this possible?



    The original standard for audio CDs placed the upper limit for storing music at 74 minutes. It was pretty easy to push this limit up to 80 minutes, however, by squeezing the data track pitch a little. Since this breaks strict compliance with the original spec, it's possible, but not too likely, that some very old CD players won't be able to handle playing 80 minute CDs.



    When you use a CD as a "red book" audio CD (plain old music CD, playable in any CD player), the data isn't quite as robustly stored as when you use a CD as a data CD. Data CDs have more redundancy and error detection/correction than audio CDs, with the trade-off that they hold a lesser amount of user data -- about 13% less.



    Adding to the confusion here is that 1 MB doesn't always equal 1 MB. There are decimal megabytes, meaning 1,000,000 bytes. There are also binary-number based megabytes, meaning 2^20 (two to the twentieth power) bytes, or 1,048,576 bytes.



    If you're measuring the size of your AIFF files in decimal megabytes, and the disc capacity is rated in binary megabytes, the numbers come out making sense. An 80 min. CDR holds 737,280,000 bytes -- roughly 737 MB(d), or about 703 MB(b) of data as a data CD. As an audio CD, however, this is 846,720,000 bytes -- roughly 847 MB(d), 803 MB(b). As long as you're talking about 842 MB(d) of AIFF files, that's an amount of audio data which should fit with a few MB to spare.
  • Reply 10 of 10
    hello12hello12 Posts: 1member

    Depends On the length  of the song file like Phineas & Ferb album

     

    one as 38 tracks & the others as 32 tracks because some of the songs are short So it will let me burn the as audio

     

    also if song go over by a few seconds then use iTunes & burn them without gaps

     

    also U can burn 4 or more on one cd id u burn I as an mp3 then u can play it on your laptop  or mp3 supported players weird how it works I know coz I am trying to burn 23 tracks to one cd   

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