How Much Audio Can You Burn On a CD-R
This is a tutorial to help you figure out how much stereo 44.1 kHz
16-bit audio data you can burn on a CD-R.
AMOUNT OF DATA: Uncompressed digital 16 bit, stereo
audio at 44.1 kHz is exactly 176,404 bytes per second (172.27 kilobytes/second).
So 1 minute is 10,584,240 bytes (10.09 megabytes), X 74 minutes
(on a standard CD-R) = a maximum of 783,233,760 bytes (746.94 megabytes)
of audio (with no 2 second gaps between songs). Now a standard 74
minute CD-R says it holds only 650 megabytes of data (681,574,400
bytes), so how is it possible that you can fit up to 746.94 megabytes
of audio (74 minutes) on a standard CD-R which appears to only hold
650 megabytes of data? There is no compression used on CD audio,
the answer is that a standard 74 minute CD-R that claims to only
be able to hold 650 MB, can actual hold 746.94 MB of CD-DA (Compact
Disc Digital Audio) IF you use no error correction code. When Phillips
& Sony invented the audio CD they built in enough extra storage
(14.915% extra) so that redundant error correction code would take
care of scratches & marks on the surface of the CD. This error
correction code (if used) brings the amount of data down to 87%
of a discs capacity which is why a CD-R capable of recording 746.94
MB of data is only rated at 650 MB.
REDUNDANT ERROR CORRECTION CODE: Unfortunately,
most audio CD-R burning software (including Adaptec's Easy CD Creator)
doesn't take advantage of the error correction code capabilities
for a CD-DA. Error correction code for audio is skipped so that
a CD-R can hold as much music as the original factory pressed CD
had. Factory pressed CDs hold more data than CD-R burnable CDs.
So, if you were able to burn audio onto a 650MB CD-R using error
correction code (called mode 1 red book CD-DA), you would only get
a maximum of about 64:23 minutes, not 74 minutes like the packaging
claims, or if you used an 80 minute CD-R you would only get about
69:21 minutes with error correction code. Most people don't know
that the 74 & 80 minute audio claim on the CD-R packaging is
without any error correction code. This means that a CD-R burned
without error correction code is more susceptible to music distortions
or flaws because of scratches, marks & other surface imperfections,
than the original factory pressed CD which has error correction.
ERROR CORRECTION CODE FOR CD-R BURNING AUDIO SOFTWARE:
So, does anyone make CD-R burning software that allows for
error correction code for CD-DA audio? Well at least one CD burning
software call Musicmatch
has been brought to my attention, as being able to turn on the error
correction feature, assuming you have enough space on the CD-R to
use this feature. The paid "Plus" version can turn on
error correction, but I'm not sure if the free "basic"
version can. The Musicmatch Burner Plus (that comes with Music Match's
Jukebox Plus software) has the option for error correction mode
when burning audio CDs. Just go Options>>Recorder>>Settings...then
look for CD Recording mode and by default "Error Correction"
(under Digital CD Recording mode) is unchecked. IF YOU KNOW OF OTHER
CD BURNING SOFTWARE THAT CAN ENABLE THE "ERROR CORRECTION"
FEATURE, PLEASE LET ME KNOW.
NON AUDIO DATA RECORDINGS: All current brands
of CD-R burning software do use error correction code when burning
data CD-Rs. Unlike music CDs where a tiny little bit of missing
or damaged information is usually tolerable & often won't be
heard by the average listener, a data CD (such as a computer program
or work file), needs to be a perfect & exact replication of
the data, so the extra areas on the CD-R reserved for error correction
code are used automatically on data CDs. When burning data CD-Rs
you will get up to 650 MB of data on a CD-R rated for 650 MB, plus
error correction code.
OVERSIZED CD-Rs: As previously mentioned, there
are CD-Rs that can hold 700 megabytes (734,003,200 bytes) of error
corrected data, or 80 minutes of stereo 16 bit 44.1 kHz audio (846,739,200
bytes) (807.51 megabytes) without error correction code.
CLOSE THE DISC, WRITE ONE SESSION: Remember that
if you want your music CD-R to be able to play on a non-computer
based CD audio player, you must write the music in a single session
& "Close the Disc". Normally a non-computer based
CD audio player will only play the first closed audio session (they
are not usually multi-session), so burn your entire CD-R audio in
one session if you expect to be able to play all the selections
on a non-computer based CD audio player.
DATA CONVERSION FIGURES: Use these figures to convert
between bytes (B), kilobytes (KB), megabytes (MB) & gigabytes
1 kilobyte = 1,024 bytes, or 1,000 bytes is really 97.65625% of
1 megabyte = 1,048,576 bytes, or 1,000,000 bytes is really 95.36743%
of a megabyte.
1 gigabyte = 1,073,741,824 bytes, or 1,000,000,000 bytes is really
93.13225% of a gigabyte.
TWO SECOND BLANK SPACE BETWEEN SONGS: Keep in
mind that it is normally desirable to have a 2 second blank space
between each song, so deduct that from the 74 minutes (or 80 minutes)
of audio space available, to determine how much you can actually
fit on a disc. Each 2 second space is 352,808 bytes (see chart below).
If you need the extra space, you can eliminate the 2 second gap
between songs when burning your CDs by using the "Disk-At-Once"
feature, but this is not normally done because songs are then butt
up against each other with no cueing space.
CHART OF HOW MUCH AUDIO FITS ON A 650 MB CD-R:
The following chart shows the amount of data used for blank spaces
between songs & what is left over to record audio files when
burning an audio CD-R with no error correction code. For example,
a CD with 10 tracks will have 9 two second spaces totaling 3,175,272
bytes (or 3.02 MB), leaving 780,058,488 bytes (or 743.92 MB) left
over for music. When totaling the sum of your wav files in File
Manager or Exploring, this chart will tell you how much music you
can fit on a standard 650 MB CD with no error correction code.
Tracks Spaces Left for audio
01 00 = 0 bytes, left 783233760 bytes (or 746.94 MB) for audio
02 01 = 352808 bytes, left 782880952 bytes (or 746.61 MB)
07 06 = 2116848 bytes, left 781116912 bytes (or 744.93 MB)
08 07 = 2469656 bytes, left 780764104 bytes (or 744.59 MB)
09 08 = 2822464 bytes, left 780411296 bytes (or 744.25 MB)
10 09 = 3175272 bytes, left 780058488 bytes (or 743.92 MB)
11 10 = 3528080 bytes, left 779705680 bytes (or 743.58 MB)
12 11 = 3880888 bytes, left 779352872 bytes (or 743.24 MB)
13 12 = 4233696 bytes, left 779000064 bytes (or 742.91 MB)
14 13 = 4586504 bytes, left 778647256 bytes (or 742.57 MB)
15 14 = 4939312 bytes, left 778294448 bytes (or 742.23 MB)
16 15 = 5292120 bytes, left 777941640 bytes (or 741.90 MB)
17 16 = 5644928 bytes, left 777588832 bytes (or 741.56 MB)
18 17 = 5997736 bytes, left 777236024 bytes (or 741.23 MB)
19 18 = 6350544 bytes, left 776883216 bytes (or 740.89 MB)
20 19 = 6703352 bytes, left 776530408 bytes (or 740.55 MB)
21 20 = 7056160 bytes, left 776177600 bytes (or 740.22 MB)
22 21 = 7408968 bytes, left 775824792 bytes (or 739.88 MB)
23 22 = 7761776 bytes, left 775471984 bytes (or 739.54 MB)
27 26 = 9173008 bytes, left 774060752 bytes (or 738.20 MB)
32 31 = 11289856 bytes, left 771943904 bytes (or 736.18 MB)
37 36 = 12701088 bytes, left 770532672 bytes (or 734.83 MB)
39 38 = 13406704 bytes, left 769827056 bytes (or 734.16 MB)
40 39 = 13759512 bytes, left 769474248 bytes (or 733.82 MB)
48 47 = 16581976 bytes, left 766651784 bytes (or 731.13 MB)
50 49 = 17287592 bytes, left 765946168 bytes (or 730.46 MB)
51 50 = 17640400 bytes, left 765593360 bytes (or 730.12 MB)
56 55 = 19404440 bytes, left 763829320 bytes (or 728.44 MB)
64 63 = 22226904 bytes, left 761006856 bytes (or 725.75 MB)
75 74 = 26107792 bytes, left 757125968 bytes (or 722.05 MB)
98 97 = 34575184 bytes, left 748658576 bytes (or 713.97 MB)
99 98 = 34927992 bytes, left 748305768 bytes (or 713.63 MB)
CHART OF HOW MUCH AUDIO FITS ON A 700 MB CD-R:
The following are examples of the amount of audio data available
on an 80 minute 700MB oversized CD with no error correction code.
Tracks Spaces Left for audio
01 00 = 0 bytes, left 846739200 bytes (or 807.51 MB) for audio (using
an 80 minute oversized disk)
02 01 = 352808 bytes, left 846386392 bytes (or 807.17 MB)
19 18 = 6350544 bytes, left 840388656 bytes (or 801.45 MB)
99 98 = 34575184 bytes, left 812164016 bytes (or 774.53 MB)
Much more in depth articles on CD-R burning can be found at http://www.mrichter.com
By Doug Hembruff.
Last updated July 4/2000