Why Can't I Play
the CDs That I Burn?
Rippit the Ogg Frog helps you figure out what's wrong when the music CDs that you burn won't play in your CD player.
This work is licensed under a
Creative Commons Attribution-ShareAlike 2.5 License.
Hi Friends! My name is Rippit.
It's cheap and easy to record compact disc "mix tapes" full of your favorite tunes. But many CD burning programs have so many options that it's not always obvious how to get what you want. Sometimes you burn a CD only to find that it won't play when you put it in your CD player. The good news is that it's usually something simple that's easily fixed when you try again.
Free Music
Try playing your CD on several different players. Will it play in some, but not others? If so, it might be burned in a format that's supported by newer CD players but not by older ones. Does it play poorly, by skipping or repeating? Either you burned your disc faster than your CD-R media is certified for, or your CD player is incompatible with the brand of CD-R disc that you recorded on. The sad fact is, not all brands of CD-R media will work in all CD players.
If you hear bursts of static, the software you used to rip the original CD might be buggy, or the original CD might have been dusty, scratched or copy-protected. Try playing the ripped audio files from your hard drive. If you hear the same bursts of static, you need to rip the original again, perhaps by using different ripping software. If your original CD is copy-protected, you need a ripper that can defeat the copy-protection so you can exercise your fair use rights.
Contents
- Did You Burn an Audio Disc or a Data Disc?
- Did You Use the Type Kind of Media?
- Eighty Minute CD-R Considered Harmful
- Try a Different Brand of Media
- Did You Burn Too Fast?
- Do You Have a Bad Rip?
- Just Say "No" to Copy-Protection
- For Further Reading
Did You Burn an Audio Disc or a Data Disc?
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Data can be stored on a compact disc in several different formats. The Compact Disc Digital Audio or CD-DA format is used to store music for home, portable or car stereo CD players. Discs in CD-DA format are also known as "audio cds". The Compact Disc Read-Only Memory or CD-ROM format is used to store data files that you can read with the CD drive on your computer. CD-ROM discs are also known as "data CDs".
The reason your CD won't play might just be that you burned it in CD-ROM format rather than CD-DA format. If so, then you'll need to set your CD burning program to burn audio cds, then try again.
What makes things complicated is that one can encode music into data files. It's also not quite right to say that audio CDs and data CDs are different things: the music on audio CDs is just digital data encoded in a format known as pulse code modulation or PCM. It's not that one kind of CD holds data while the other holds sound; what makes the difference is how the CD is used or played.
It's not always easy to tell what kind of CD you have. Some newer CD players will play "MP3 CDs", or data (CD-ROM) cds full of MP3 files. It's important to understand that while the MP3 files on the CDs contain audio, the CD itself is in CD-ROM rather than CD-DA format.
How to Find a CD's Format on Mac OS X
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It's easy to tell the difference on Mac OS X: put your CD into your Mac's CD drive, then wait for its icon to appear on your desktop. Click on it once to select it, then choose "Get Info" from the Finder's File menu. Look for the "Format" item in the Info window that appears. If it says "Audio CD" then that's what you have - you burned it in the right format. (But read on to learn about other reasons it might not play.) If it says "ISO 9660", "HFS" or "HFS+" then it's a data CD or CD-ROM.
(ISO 9660, HFS and HFS+ are known as "filesystems", which are used to organize the files and folders on a data CD or hard disk so a computer's operating system can keep track of them.)
How to Find a CD's Format on Windows
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You would think it's just as easy to find out on Windows: just right-click on your CD drive's icon in My Computer, then select Properties from the menu that pops up. But Rippit tried this just now, and what I found is that both audio and data CDs are reported to have a filesystem of "CDFS". I think Windows uses its CDFS filesystem device driver for both audio and data CDs.
There is a way: Windows adds a filename extension of ".cda" to the tracks on audio CDs. Windows hides filename extensions by default though. There are two ways to view them: you can set your Windows Folder Options so they aren't hidden, or you can open a Command Prompt window and use the "dir" command to look at a directory listing.
Follow these steps to unhide filename extensions
- Double-click your "My Computer" icon.
- From the Tools menu, select Folder Options
- Click on the View tab
- Uncheck the checkbox next to "Hide Extensions for Known File Types"
- Click the OK button
Now put your CD in your computer's CD drive, then double-click its icon in your "My Computer" window. If all the files listed in it end with ".cda", then you have an audio or CD-DA cd. If any of the file names end with ".ogg", ".flac", ".mp3", ".wav", ".aac", ".m4a", ".m4p" or ".wma", then you have a data CD, or CD-ROM, that has audio files on it. If there are any other extensions, then you may have data files that aren't audio files. If there are any folders, then you definitely have a data CD, as audio compact discs cannot contain folders.
How to Find a CD's format on Linux
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The Linux "file" program can identify many file types by examining the data values at the beginning of the files. Many file formats provide a value called a Magic Number to make identification easier, and to reduce the risk of using the wrong kind of file.
If your CD is a data CD, or CD-ROM, the file command will tell you what kind of filesystem is on it, but it needs a couple command line arguments to work for CDs:
Most Linux distributions create a symbolic link called /dev/cdrom which accesses the CD drive. Give file the -L or --dereference argument to follow the link to its destination file rather than examining the link itself.
On Linux and other Unix variants, hardware devices are accessed via special files (or device files) that are found in the /dev directory. Sometimes even reading a special file may cause the underlying harware to operate in unintended ways. To prevent this, by default the file command does not read the contents of special files. Instead, it will just print a message about what kind of special file it is. You can make the file command read the special file by supplying the -s or --special-files argument.
Either of these two command lines will work, and are equivalent:
$ file -s -L /dev/cdrom /dev/cdrom: ISO 9660 CD-ROM filesystem data 'CDROM '
or...
$ file --dereference --special-files /dev/cdrom /dev/cdrom: ISO 9660 CD-ROM filesystem data 'CDROM '
Unfortunately, the file command can't identify audio CDs. If you try, you'll get a message like this:
/dev/cdrom: ERROR: cannot read `/dev/cdrom' (Input/output error)
That could mean something else though, for example that the CD is blank or corrupt. (If there is no CD in the drive at all, file will wait forever for one to be inserted. If this happens to you, press the eject button on your drive, then insert a CD to get it unstuck.)
There doesn't seem to be one program that can identify both audio and data CDs, but CDDA Paranioa will print the Table of Contents of audio CDs if you give it the -Q or --query arguments. The command-line version of CDDA Paranoia is actually called cdparanoia:
# cdparanoia --query cdparanoia III release 9.8 (March 23, 2001) (C) 2001 Monty <monty@xiph.org> and Xiphophorus Report bugs to paranoia@xiph.org http://www.xiph.org/paranoia/ Table of contents (audio tracks only): track length begin copy pre ch =========================================================== 1. 13802 [03:04.02] 0 [00:00.00] no no 2 2. 12168 [02:42.18] 13802 [03:04.02] no no 2 ...
If cdparanoia finds a data CD in the drive, it will print "Unable to open disc."
If You Burned the Wrong Format
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If you have a data CD full of audio files, you will be able to play it on your computer. You won't be able to play it on most CD players, but you might be able to play it on some of them. Why? Because many newer CD players also support "MP3 cds", that is, CD-ROMs full of MP3s or other audio files. But these players require special software and circuitry to play such CDs. If you don't understand the distinction, it won't make sense to you why your CD will play on some players but not others.
Most, but not all CD burning applications will burn both data and audio CDs. There is some possibility that the one you used doesn't support burning audio CDs at all. Make sure that your burning program both supports audio CDs and is actually configured to create them - it might be set to make either data or MP3 cds. Unfortunately there are many CD burning tools available, so Rippit cannot possibly tell you how to configure them all. But future HOWTOs will explain how to use the burners that are Free Software (that is, Free as in Freedom).
It's possible that the program you used to burn your CD does not understand the format of the audio files you wanted to burn. For example, cdrecord can only burn audio from WAV, AU and raw Pulse Code Modulated files. It won't work to try to make cdrecord burn audio directly from MP3 or Ogg Vorbis files. You will have to decode your file to WAV format then burn that.
Did You Use the Wrong Type of Media?
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You should use CD-R (Compact Disc Recordable) discs for burning audio CDs. CD-RW (Compact Disc ReWritable) discs may or may not work, as rewritable (or erasable) discs use a different recording technology that most audio CD players cannot read. I have seen CD players sold in stores that advertised CD-RW compatible; this works because special support for CD-RW media is designed into the player. (I also have an older CD-ROM drive that can't read CD-RW data discs.)
DVDs (Digital Versatile Discs) do not work in CD players. Specifically, none of the following types of media will work in audio CD players: DVD-R, DVD-RW, DVD+R, DVD+RW. You might be tempted to try burning DVDs because they can hold a lot more data than CDs, but DVD discs have a format that is mechanically and optically different from CD discs:
Both CD and DVD discs encode their data as a series of microscopic spots winding out in a spiral starting just outside of the hub of the disc. But the spirals on DVD discs are wound much tighter, and the spots that encode the data on DVD are much smaller than on CD discs.
Now, you can burn audio files to DVD discs that can be played by a computer that's equipped with a DVD-ROM drive. But they won't work in audio CD players.
Eighty Minute CD-R Considered Harmful
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Standards-Compliant CD-R Media
The Red Book audio CD specification provides for audio discs that store up to 74 minutes of sound, stored as a series of microscopic spots that trace a spiral track starting just outside the hub of the disc and proceeding towards the edge. (Rippit heard once that the length of audio CDs was chosen to just fit Beethoven's Ninth Symphony on one uninterrupted disc. I don't know for sure.) The Yellow Book spec for CD-ROM provides for data CDs that hold about 650 megabytes of data.
Blank CD-R discs are imprinted with a spiral groove that guides the burner as it burns. By winding the spiral a little tighter than the standards specify, audio CD-Rs can be made to hold up to 80 minutes of music, and data CD-Rs up to 700 megabytes of data.
You might think that's great, but there's a serious problem with such CD-Rs: they violate the standards specification in such a way that such discs won't work on some players or drives, particularly older ones that were manufactured before the tighter-spiral scheme was invented. Sometimes the discs even get stuck in the player, which has to be pried open to get them back out.
For maximum compatibility, you're better off sticking to 74 minute, 650 megabyte CD-R media. Limit your use of the higher capacity blanks to occasions when you really need the extra space.
Unfortunately, most people are under the mistaken impression that the higher-capacity discs are a better value, so that's the only kind many stores sell anymore. Rippit asked around, and found some seventy-four minute media that you can purchase online by clicking the product links given here.
Try a Different Brand
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Even if you always burn CD-R discs, you might find that some brands of discs play well while other brands don't. One symptom of brand incompatibility is that the player skips erratically through the tracks. You might also find that your CD-R's play correctly when they are freshly burned, but degrade rapidly after just a few days or weeks.
The original "Red Book" CD-DA audio CD format was written before recordable CDs were invented. CDs made to Red Book specifications are pressed from a "glass master"; that is, a glass plate with microscopic raised bumps on it is pressed against a smooth plastic disc to create a spiral pattern of spots that encode the audio data. Thus, glass master CDs are stamped, not burned.
CD-R discs are said to be "burned" because heat from a focussed laser beam darkens a chemical dye that forms one layer of the disc. The burned and unburned spots in the dye simulate the reflectivity of the bumps and flat spots in glass master-pressed CDs. However, the simulation is not perfect, and if your CD player wasn't designed to also play CD-Rs, it might not play them reliably.
Unfortunately, some brands of CD-R will work in some players but not others. Older players are likely to have the most trouble. There is no one single brand of media that is guaranteed to work everywhere. Why? Because the chemical dyes used to record data on CD-R discs are patented by the companies that developed them. Every company that manufactures CD-R discs had to invent its own unique dye formula. Each different dye works a little bit differently from the others, with the result that each works in some players but not others.
The best you can hope for is to find a brand of CD-R media that works for the particular CD players you own. If you find that your audio CD-Rs don't play reliably, try buying a different brand of blank discs, then stick with whatever brand works best for you. Avoid purchasing large quantities of blanks until you are sure you have the best brand.
This is bad news for musicians: if you want to burn audio CDs to distribute to your fans, some of your fans my find that their CDs won't play. I don't know any way to guarantee every CD-R will play for everyone who tries it. The good news is that today's CD players are usually engineered for CD-R compatibility, so your CD-Rs will likely only cause trouble when played on older players.
Did You Burn Too Fast?
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Each brand of CD-R media is certified for a maximum burning speed, expressed as a multiple of the standard audio playback speed; thus, a "52x" CD-R can be reliably burned while spinning up to fifty-two times faster than an audio CD spins while playing. If you burn it faster than the rated speed, the audio data won't be reliably written to the disc. This may cause the player to skip erratically through the disc, or to play up to a certain point and then stop.
Well-engineered burning software won't burn a CD faster than its rated speed, but not all burning software is well-engineered! Unfortunately, some programs that I've tried default to burning "as fast as possible", that is, as fast as the burner's mechanism will spin, which may be faster than the media is certified for. Some poorly-written burning software allows you to set the burning speed, but doesn't save your setting from one burn to the next, so you have to take care to reset it every time.
Unless you really are in some kind of hurry, you're better off burning at less than the maximum rated speed, because that will give you some safety margin to guard against failure due to manufacturing defects in your burner or the disc.
Do You Have a Bad Rip?
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"Ripping" is the process of extracting the raw digital audio data from audio CDs so it can be saved in data files on your computer's hard disk. Audio and data CDs are encoded with extra error correction data in each disc sector, to recover from data loss caused by scratches or dust on the surface of the disc. To enable audio CDs to hold more music, the error correction used for audio CDs is not as robust as that used for data CDs. This, ripping a CD can be unreliable.
If the CDs you burn have bursts of noise or static in them, try ripping your original CDs to WAV files on your hard drive, then play back the WAV files. If the WAV files also have bursts of static, you might have a bad rip. You can often fix this by ripping at a slower speed or enabling error correction in your ripping software. Rippers that use CDDA Paranoia as their low-level ripping engine are likely to work best, as it has particularly robust error correction built-in.
A bad rip might also be caused by buggy burning software. One reason Rippit decided to start this whole project is that I ripped a hundred CDs with iTunes, only to find that many of the MP3s it made were corrupted.
Just Say "No" to Copy-Protection
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Some music labels violate the Red Book audio CD specification by building copy protection into the CDs they publish. One way of copy-protecting a CD is to monkey with the error correcting codes in such a way that the disc will play just fine on an audio CD player, but you can't get a good rip on a computer; ripped files will have many bursts of noise. Sometimes copy-protected CDs will get stuck if you try to play them in a computer's CD-ROM drive, even if you're not trying to rip them.
Rippit recommends that you take copy-protected CDs back to the store you bought them from so you can demand a refund. Be on the lookout for copy-protected CDs in the future so you can avoid buying them. Most CDs aren't copy-protected, so there is no lack of music for you to enjoy without having to deal with Digital Rights Management (DRM) that violates the CD-DA engineering standards specifications.
If you still want to rip a copy-protected CD, you will find that some rippers work better than others. Success may also depend on the particular CD-ROM drive hardware that you use. Most copy-protection is designed to break rippers that run on Windows or Mac OS; you may have better results if you try ripping under Linux.
How to defeat copy-protection so you can enjoy your Fair Use rights will be the subject of a future Digital Music How-To Article. Rippit asks for your patience while he conducts the necessary research.
For Further Reading
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You can find a wealth of information on all aspects of CD burning by reading the CD-Recordable FAQ (Frequently Asked Questions). I'll also be covering many more topics in the coming weeks in Ogg Frog's Digital Music How-To Articles, so bookmark this page and check back later.
If you found what I had to say helpful, be sure to tell your friends!
-- Rippit the Ogg Frog rippit@oggfrog.com
What the Bold Print Giveth, the Fine Print Taketh Away
Copyright © 2006 Michael D. Crawford.
Ogg Frog, Rippit, Rippit the Ogg Frog, the Frog logo and the Circle Flowers logo are trademarks of Michael D. Crawford. All other trademarks are the property of their respective owners.
So there.