CD-Recordable FAQ - Section 3

CD-Recordable FAQ - Section 3


[3] How Do I...

[3-1] How do I copy a CD-ROM?
[3-1-1] Why can't I just do a block copy like a floppy?
[3-2] How do I extract tracks from ("rip") or copy an audio CD?
[3-2-1] How do I remove the voice from a CD track, leaving just music?
[3-2-2] How do I encode a CD track to MP3?
[3-3] How do I get rid of hisses and clicks on audio CDs?
[3-4] How do I copy game console discs (e.g. Playstation, Dreamcast)
[3-5] How do I get filenames onto a disc?
[3-5-1] ISO-9660
[3-5-2] Rock Ridge
[3-5-3] HFS
[3-5-4] Joliet
[3-5-5] Romeo
[3-5-6] ISO/IEC 13346 and ISO/IEC 13490
[3-6] How do I use a CD disc on my computer?
[3-7] How can I extract disc and track titles from an audio CD?
[3-8] How do I write more than 74 minutes of audio or 650MB of data?
[3-8-1] How well do 80-minute CD-R blank discs work?
[3-8-2] How well do 90-minute and 99-minute CD-R blank discs work?
[3-8-3] How can I exceed the stated disc capacity ("overburning")?
[3-9] How do I put photographs onto CD-ROM?
[3-9-1] How do I create a PhotoCD?
[3-9-2] How can I set up a photo album on CD-ROM?
[3-9-3] How can I show digital photos on my DVD player?
[3-10] How do I make a CD that will work on a PC or a Mac?
[3-11] How do I access different sessions on a multi-session CD?
[3-12] How do I transfer my records or cassettes to a CD?
[3-12-1] How do I transfer my records or cassettes to a CD with a stand-alone audio CD recorder?
[3-12-2] How do I transfer my records or cassettes to a CD with a CD recorder attached to my computer?
[3-12-3] How can I clean up the audio before recording?
[3-13] How do I transfer an audio DAT tape to CD?
[3-14] How do I put audio and data on the same CD?
[3-15] How do I make a bootable CD-ROM?
[3-16] How do I convert home movies into video on CD?
[3-16-1] How do I create a VideoCD from AVI or MPEG files?
[3-16-2] How do I create an SVCD?
[3-16-3] How do I create an AVCD?
[3-17] How can I burn several copies of the same disc simultaneously?
[3-18] Can I make copies of copies?
[3-19] How can I compress or encrypt data on a CD-ROM?
[3-20] Can I do backups onto CD-R?
[3-21] How do I automatically launch something? Change the CD icon?
[3-21-1] How does Windows "autorun" work?
[3-21-2] How do I launch a document (like a web page)?
[3-21-3] What autorun software is available?
[3-22] How can I be sure the data was written correctly?
[3-23] How do I create, copy, or play Audio Karaoke/CD+G discs?
[3-24] How do I copy a CD-ROM with 3GB of data on it? A huge VideoCD?
[3-25] How do I get my CD-R pressed into a real CD?
[3-26] How do I make a CD without that two-second gap between tracks?
[3-27] How can I record RealAudio (.ra), MIDI, WMA, and MP3 on a CD?
[3-28] How do I add CD-Text information?
[3-29] Can I distribute a web site on a CD-ROM?
[3-30] How do I clean my CD recorder?
[3-31] Is it better to record at slower speeds?
[3-32] Where do I get drivers for my CD recorder?
[3-33] Can I copy discs without breaking the law?
[3-33-1] Can I copy discs without breaking the law in the United States of America?
[3-33-2] Can I copy discs without breaking the law in Canada?
[3-34] Can CD-Rs recorded at 2x be read faster than 2x?
[3-35] How do I make my CD-ROM work on the Mac, WinNT, and UNIX?
[3-36] How do I put "hidden tracks" and negative indices on audio CDs?
[3-37] Do I need to worry about viruses?
[3-38] How do I cover up a bad audio track on a CD-R?
[3-39] How do I duplicate this hard-to-copy game?
[3-40] Should I erase or format a disc? How?
[3-41] How do I equalize the volume for tracks from different sources?
[3-42] How do I make a bit-for-bit copy of a disc?
[3-43] How do I put punctuation or lower case in CD-ROM volume labels?
[3-44] How do I extract audio tracks from an "enhanced" CD on the Mac?
[3-45] How do I disable DirectCD for Windows?
[3-46] How do I specify the order of files (e.g. sorting) on ISO-9660?
[3-47] How do I put a password on a CD-ROM?
[3-48] Can I record an audio CD a few tracks at a time?
[3-49] How do I copy DVDs onto CD-R?
[3-49-1] I heard about software that copies DVDs with a CD recorder!
[3-50] How do I copy Mac, UNIX, or "hybrid" CD-ROMs from Windows?
[3-51] How do I copy something in "RAW" mode? What's DAO-96?
[3-52] How do I do cross-fades between audio tracks?
[3-53] How do I create a CD with my favorite songs on it?
[3-54] How do I record directly onto CD from a microphone?
[3-55] Is it okay to record a CD from MP3?
[3-56] How can I test a disc image before recording?
[3-57] How do I clear the "read-only" flag under Windows?
[3-58] How do I share a CD recorder across a network?


Subject: [3] How Do I...

This is general information about recommended ways to do specific tasks.


Subject: [3-1] How do I copy a CD-ROM?

Just about every piece of CD recording software comes with a CD copier. In some cases it's a stand-alone extra, in some it's integrated with other features, and in a few cases the software does nothing else.

Most disc copying software will allow you to make a CD image on a hard drive that can then be written to multiple CDs. A few will allow you to record the same image to multiple CD recorders simultaneously (see section (3-17)).

It's important to remember that, when copying directly from one CD to another, the source MUST be faster than the target, and must be error-free. If the source pauses or spins down to read a marginal area of the disc, the target may outrun the source, and the CD-R will only be useful as a frisbee. Most programs have a "test write" feature that put the CD-R device into a mode where it goes through all the motions but doesn't actually write anything; it's a good idea to do this right before copying something for the first time.

If you're wondering about copying Mac CD-ROMs on a PC or vice-versa, see section (3-50).

Some suggestions for software good at copying a variety of discs:

CloneCD (6-1-49)
Very good at copying difficult (esp. copy-protected) discs.
CDRWIN (6-1-7)
Good at copying discs, also very nice for fancy audio CDs.
Disc Juggler (6-1-27)
Can copy to more than one device at a time.
CDRDAO (6-1-47)
Runs under a wide variety of operating systems.
For copying simple audio CDs and un-protected CD-ROMs, standard applications like Nero or Toast will work just fine.

See section (2-4) for more information about copy protection, section (3-51) for the details on "RAW" reads, and (3-4) for some notes on game console discs.


Subject: [3-1-1] Why can't I just do a block copy like a floppy?

CDs don't have circular tracks. They're laid out on a spiral, with multiple sessions composed of multiple tracks composed of sectors, and the data in the sectors is interleaved and spread over a large area. The sector format is standard, but there's more than one standard.

"The nice thing about standards is that you have so many to choose from."
-- Andrew S. Tanenbaum, _Computer Networks_, 2nd ed, p.254

The ability to read certain portions of a CD depends on the CD firmware. Some CD players aren't capable of understanding multi-session discs or of reading audio tracks as digital data. Jitter, described in section (2-15), is also a problem for most drives.


Subject: [3-2] How do I extract tracks from ("rip") or copy an audio CD?

Start with the CD-DA FAQ [once at http://www.tardis.ed.ac.uk/~psyche/cdda/, currently missing?] Take a look at http://come.to/cdspeed to see if your CD-ROM drive is up to the task. EAC, from http://www.exactaudiocopy.de/, is often recommended for extracting ("ripping") audio tracks.

To copy from CD to CD, the source drive needs to support digital audio extraction, which is rare among older drives but universal in current models. Ideally, the copy program will use disc-at-once recording to produce a duplicate that mimics the original as closely as possible. As with copying CD-ROMs, you must be able to read data off of the source drive faster than your recorder is writing. If you can only extract audio at 1x, you're not going to be able to do a CD-to-CD copy reliably.

If you're just interested in extracting digital audio, you don't even need a CD-R unit, just a CD-ROM drive that supports Digital Audio Extraction (DAE) and some software. The CD-DA sites noted at the top of this section list drives that support DAE, have software to evaluate your existing drive, and have links to several different DAE applications.

Different drives can extract digital audio at different speeds. For example, the Plextor 6Plex can extract audio at 6x, while the NEC 6Xi can only extract at 1x. Most recent drives extract at well over 20x, which is about the limit for an IDE drive that doesn't support DMA.

Some CD-ROM and CD-R drives have trouble extracting digital audio at high speed, so if you're getting lots of clicks and pops when extracting you should try doing it at a slower speed. You may also run into trouble if you try to extract faster than your hard drive can write. One user found that he was able to eliminate clicks and pops by defragmenting his hard drive. Another found that the Win95 "vcache" fix (section (4-1-2)) solved his problems.

It should be pointed out that, while digitally extracted audio is an exact copy of the data on the CD, it's an exact copy as your CD player perceives it. Different drives or different runs with the same drive can extract slightly different data from the same disc. The differences are usually inaudible, however. Some newer drives will report the number of uncorrectable errors encountered, so you can get a sense for how accurate the extraction really is.

The quality of the audio on the duplicate CD-R, given a high-quality extraction, depends mostly on how well your CD player gets along with the brand of media you're using. See the next section for some comments about avoiding clicks and pops.

Some older drives have trouble starting at the exact start of audio tracks. The extraction starts a few blocks forward of where it should, and ends a few blocks later, so the track may not sound quite right and the extraction program will report errors at the end of the last track. See section (4-19).

The Lite-On LTN483S 48x CD-ROM drive has a fairly unique bit of brain damage: it doesn't extract the last two seconds of a track correctly. This is only apparent on audio CDs with a "cold stop", where the music plays right up to the very end of the track. If the track has two seconds of silence at the end, there are no apparent problems. Apparently there is a firmware fix for this (the PD03 update), available from http://support.euro.dell.com/de/de/filelib/download/index.asp?fileid=R20664 or http://support.dell.com/us/en/filelib/download/index.asp?fileid=R20664.

One minor note: the data on audio CDs is stored in "Motorola" big-endian format, with the high byte of each 16-bit word first. AIFF files also use this format, but WAV files use "Intel" little-endian format. Make sure your software deals with the endian-flipping correctly. Byte-swapped CD audio sounds like "static".


Subject: [3-2-1] How do I remove the voice from a CD track, leaving just music?

A common reason for wanting to do this is to have a disc that can be sung along with, either for personal practice or for karaoke. There isn't a perfect method for doing this, but it's possible to get close with some CDs.

Music is generally recorded in independent tracks and then mixed into a balanced whole. The recording studio can create masters with or without the vocals, which is where a "clean" karaoke source comes from. The music is usually recorded in stereo, and the vocals in mono (the singer has one microphone). The mixed result has slightly different signals on the left and right channels for the music, but the same signal on both channels for the vocals. By removing all signal components that are equal on the left and right channels, the vocals can be removed with relatively little distortion of the music. This is called "center channel elimination".

This doesn't always work out in practice. If the track in question doesn't keep the vocals "centered", all bets are off. Many musicians apply effects to the vocals to achieve a certain effect -- often, to make it sound like they can sing better than they actually can. These effects aren't usually "centered", so part of the voice remains.

Center channel elimination can be done with a good sound editor, such as Cool Edit 2000 (6-2-14). The procedure to follow with Cool Edit is:

  • Extract the CD track into a WAV file.
  • Load the WAV file into Cool Edit.
  • Create a new window with no WAV file in it (File->New...). Set the settings at 44.1KHz 16-bit *mono*.
  • Switch back to the original WAV file (with the "Window" menu).
  • Select the entire left channel in the original WAV file. If you move the mouse to the top of the WAV display area, the mouse cursor gets a little 'L' next to it. Pick a spot near the middle of the screen, left click, and drag all the way to the left edge. Then move the cursor back to the middle, right click, and drag all the way to the right edge. You should now have the entire left channel selected.
  • Select "copy". Switch to the new WAV file, and select "paste". Switch back to the original.
  • Move the mouse cursor near the bottom of the WAV graphic until the mouse pointer gets an 'R' next to it, and select the entire right channel the way you did the left.
  • Select "copy". Switch to the new WAV file. From the Edit menu, select "Mix paste...".
  • Select "Overlap (Mix)", volume of 100, and check the "Invert" checkbox. Click "OK".
The result is a single track with the center channel removed. Hit the "play" button and see what it sounds like.

The converse operation -- extracting the vocals and deleting the music -- is not currently possible. (If you express the situation mathematically, the problem is one of three variables in two equations. The software needs a new feature that subtracts tracks and retains the other part.)


Subject: [3-2-2] How do I encode a CD track to MP3?

Extract the audio from the CD, then encode it into an MP3 at a quality level you like. Some programs combine the "rip" and "encode" into one easy step.

Higher quality settings result in larger MP3 files. Most people can't tell the difference between an MP3 at 160Kbps and the original.

Some tutorial sites:

Some software sites (mostly for Windows): There are others. The quality of the result depends greatly on the quality of the encoder. There is no "best" encoder, but the Fraunhofer codec and the Blade encoder usually do well.

If your MP3s have a static sound in them, you might be getting a bad "rip". The all-in-one rip+encode programs don't always do a great job extracting audio from the CD. You may want to "rip" the audio manually with EAC (6-2-12) and then encode the WAV files. (Recent versions of EAC can extract to MP3 if you have a codec installed.)


Subject: [3-3] How do I get rid of hisses and clicks on audio CDs?

If you're interested in removing noise from audio captured from an analog source, such as a record player or analog cassette tape, skip to section (3-12-3). This section is about unexpected noise in audio from digital sources, such as tracks extracted from a CD. (Start with section (3-2) if you are new to "ripping" or copying audio tracks.)

The single most important rule of noise removal is to figure out where the noise came from. Play the .WAV files off of your hard drive (if you're doing direct CD-to-CD copies, extract a track and listen to it). If you hear noise in the .WAV on your hard drive, the digital audio extraction isn't working very well. You either need to extract more slowly, extract from a different device, find a program that works better, or maybe just clean the dust and grime off the source CD. For more information, including a URL for recommended software and the CD-DA FAQ, see section (3-2).

Always start by inspecting the CD. If you borrowed it from a library, don't expect it to be in pristine condition. With enough abuse, even CDs will sound bad, and audio *extraction* is more susceptible to such errors than audio *playback*. (This is what makes copy-protected CDs possible; see section (2-4-2).)

If the problem sounds like repeated or skipped samples, rather than clicks or hissing, the problem is probably jitter during extraction. See section (2-15) for an overview, and then give EAC a try (section (6-2-12)).

A nifty trick for comparing two .WAV files is to use the "Mix Paste" feature in Cool Edit. Extract a track twice, then use Mix Paste to copy an inverted version of one file on top of the other. The two sound files will cancel each other out wherever they are identical, and have little spikes where they are different. This can be useful for seeing if the problems are only on one channel or are happening at regular intervals. You need to make sure though that both files start at the same place though. If your CD-ROM drive doesn't always extract from the start of the block, you will need to adjust the files so they line up.

Useful things to do with this include comparing two extractions from the same drive, extractions from different drives, or extractions from the CD-R you just wrote to the original .WAV file you used to write it.

If you just want to see if the files are the same, use the DOS File Compare command, with the "binary" switch set: FC /B FILE1.WAV FILE2.WAV.

Some CD-ROM drives may put a click a few seconds into the first track being extracted. This appears to be related to the drive spinning up. Try starting the extraction, cancelling, and then immediately restarting.

It is possible, though still somewhat unlikely, that you are trying to extract from a copy-protected CD. Section (2-4-2) discusses this in some detail.

The rest of this section only applies if the extracted audio sounds fine on disk, but has problems when played back from the CD-R.


If you're using track-at-once recording, you may get a short click or silent "hiccup" at the start of each track. Hiccups are unavoidable, but you should be able to get rid of the click by using different software.

If you're using disc-at-once recording, and are still getting a short click at the *start* of every track, then your recording software is probably writing the sound file with the headers still on it. You should either use a smarter program, or remove the header manually (see the URL for "StripWav", below).

If you are getting clicks in the middle of a track, they are either being added when pulling the data off the disc or when writing it. If the .WAV (AIFF on the Mac) file plays without clicks, then your CD recorder may be failing somehow during the write process. Some people who got "static" in audio recorded on an HP 4020i found that reducing the DMA transfer rate to 2MB/sec helped.

One user was told by Yamaha tech support that crackling (similar to a dirty vinyl LP) was a symptom of laser misalignment. If you've been writing audio CDs for quite a while, but lately you've been getting "crackly" results from tried-and-true media, this might be the culprit. Since it requires returning the unit for repair, you should exhaust all other possibilities first. (Side note: it's not clear how a laser gets "misaligned". They have to adjust themselves constantly to stay in the spiral groove. It might be due to poor focus, but that should be causing all kinds of problems.)

If you are getting clicks at the end of a track, it's possible that the software used to create the .WAV file put some information at the very end, which is legal but not handled correctly by some CD-R software. See section (3-12-3) for tips on using CoolEdit to remove the data. If you are finding that tracks extracted from CDs don't have clicks but tracks that you have recorded or edited do, chances are the data size isn't a multiple of 2352 bytes, and the last block is being filled with junk. This is common on live recordings or when large tracks are cut into smaller ones. Jeff Arnold's DAO will fill out the last block with zeros (digital silence) if there is space left over, but most of the other programs will write garbage that is audible as a short (less than 1/75th second) click. The fix is to split the track on 2352-byte block boundaries.

A program called "StripWav" will remove .WAV headers and footers that may be interfering with some applications. The program is available from http://www.lightlink.com/tjweber/.


If you must use track-at-once, make sure you're writing it all in one session. PC-based CD players may be able to see tracks in later sessions, but the CD player in your stereo system almost certainly can't.

A distantly related problem can arise if you use "shuffle play" to play random tracks from a CD-R. If the audio of track N begins immediately, some CD players will slide from the end of track N-1 into the start of track N, playing a short burst of track N before seeking elsewhere. This can be avoided by putting a gap at the start of such tracks (e.g. with "INDEX 01 xx:yy:zz" in a DAO cue sheet).


Subject: [3-4] How do I copy game console discs (e.g. Playstation, Dreamcast)

For PCs, CloneCD (6-1-49) or CDRWIN (6-1-7) should work as well as anything. For Macs, Astarte's CD-Copy (6-2-8) used to be recommended but may no longer be available.

Note that the software does NOT defeat the copy protection. I'm told that the "copy protection" on Playstation discs is in fact a region code -- America, Europe, Japan -- encoded near the start of the disc. The "MOD chip", a device attached to the Playstation that defeats one aspect of the copy protection, emulates the country code reading process. It sends all three region codes back, enabling the game console to play original discs from other regions as well as copied discs. Some people say the code is written in a block with damaged ECC, some say it's in the barcode on the hub, others have insisted that it's in the ATIP region of the lead-in. Whatever the case, it doesn't get copied by a CD recorder, and claims of hacked recorder firmware that can create MOD-chip-free duplicates are false.

Instructions for copying discs and vendors who sell MOD chips can be found by searching the net. If you don't have a PC, or if your drive doesn't support disc-at-once recording, you will need to look for disc copying instructions on the net.

Sega Dreamcast discs use a proprietary format, called GD-ROM, which can hold 1GB of data. This makes it impossible to make an exact copy, though it is possible in many cases to copy "enough" stuff to make them work. Persistent rumors claiming that CeQuadrat's PacketCD can copy the discs are false. GD-R (Gigabyte Disc Recordable) media has two regions, a "single-density" area near the hub and a "high-density" area farther out. A visual inspection of GD-R media suggests that the single-density area starts at about 22mm from the disc's center (same as a CD-R) and goes to 29mm. From 29mm to 31mm is a "no-mans" land that isn't recordable, and the high-density area goes from 31mm to 58mm. An image of one is available on http://www.fadden.com/cdrpics/.

Incidentally, posting requests or advertisements for pirated software on one of the non-warez Usenet groups is generally regarded as a mark of extreme stupidity. Whatever your opinion of software piracy, it is against the law in much of the world.


Subject: [3-5] How do I get long filenames onto a disc?

There are several different ways, most of which only work with some operating systems. The next few sections discuss the various methods. See http://www.roxio.com/en/support/cdr/filesystems.html for a compatibility chart.

It's important to remember that the most common CD filesystem (ISO-9660 Level 1) only supports eight-character filenames with a three-character extension. Longer filenames are added either as an extension to ISO-9660 (Joliet, Rock Ridge) or a replacement (UDF, HFS). These are discussed in the sections below.

Getting mixed-case filenames onto a disc is a similar problem. Burning an ISO-9660 disc with lower-case filenames isn't recommended, because some systems aren't able to access the files even though they appear in directory listings.

"mkhybrid" and recent versions of "mkisofs" (1.12b1 or later), described in sections (6-1-32) and (6-1-10), respectively, are able to create CDs that have both Joliet and Rock Ridge extensions. "mkhybrid" can create discs with Joliet, Rock Ridge, and Mac HFS on the same disc, sharing the same file data.


Subject: [3-5-1] ISO-9660

Level 1 ISO-9660 defines names to be the familiar 8+3 convention that MS-DOS users have suffered through for many years: eight characters for the name, a period ("full stop" for those of you in the U.K.), followed by three characters for the file type, all in upper case. The only allowed characters are A-Z, 0-9, '.', and '_'. There's also a file version number, separated from the name by a semicolon, but it's usually ignored.

Files must occupy a contiguous range of sectors. This allows a file to be specified with a start block and a count. (Most disk-based filesystems require index blocks that list all the blocks used by a file.) The maximum directory depth is 8.

Level 2 ISO-9660 allows far more flexibility in filenames, but isn't usable on some systems, notably MS-DOS.

Level 3 ISO-9660 allows non-contiguous files, useful if the file was written in multiple packets with packet-writing software. Also unavailable under MS-DOS. For the Mac, you can add support by installing Joliet Volume Access (http://www.tempel.org/joliet/).

Some of the CD creation programs will let you select how closely you want the CD to conform to the ISO-9660 standard. For example, Easy-CD Pro 95 can restrict filenames to be ISO-9660 compliant, or allow the full set of valid MS-DOS filenames. (Most systems can handle MS-DOS filenames.)

Incidentally, the ISO-9660 spec requires that all files be displayed in alphabetical order, with directories first, no matter how they are recorded on the CD-ROM. You can't arrange files on the disc, because the ISO-9660 reader (e.g. MSCDEX) sorts them before displaying them.


Subject: [3-5-2] Rock Ridge

The Rock Ridge extensions to ISO-9660 define a way for UNIX-isms like long mixed-case filenames and symbolic links to be supported.

Because it's still an ISO-9660 filesystem, the files can still be read by machines that don't support Rock Ridge; they just won't see the long forms of the names.

Rock Ridge is supported by UNIX systems. DOS, Windows, and the Mac don't currently support it.

Copies of the Rock Ridge standard and System Use Sharing Protocol (SUSP) can be found at ftp://ftp.ymi.com/pub/rockridge/. Pay a visit to http://makecd.core.de/Rock_Ridge_Amiga_Specific for a description of Amiga-specific extensions.


Subject: [3-5-3] HFS

HFS is the Hierarchical File System, used by the Macintosh. This is often used instead of the ISO-9660 filesystem on Mac CD-ROMs, making the disc unusable on systems that don't support HFS.

At present, the systems that can natively read HFS CD-ROMS are Macs, Amigas (with AmiCDROM, available from ftp://ftp.cdrom.com/pub/aminet/disk/cdrom/), PCs running Linux or OS/2 (with appropriate patches), the Apple IIgs, and SGI machines running Irix (they appear as AppleDouble format).

Windows machines can read HFS disks with the appropriate software. One example is "Conversions Plus" from Data Viz, http://www.dataviz.com/products/conversionsplus/. Another is MacDisk, from http://www.macdisk.com/prospen.php3.

Some authoring packages for the Mac and Windows allow the creation of "hybrid" CDs that have both an ISO-9660 filesystem and an HFS filesystem. Such discs can be used on non-Mac systems, but still have all the file attributes (creator type, resource fork) that Mac OS likes.

Apple has defined some ISO-9660 extensions that allow Macintosh files to exist with file and creator types on ISO-9660 CD-ROMs. A description of the extensions is available as tech note FL 36 from: http://developer.apple.com/technotes/fl/fl_36.html


Subject: [3-5-4] Joliet

Microsoft, being Microsoft, created their own standard called "Joliet". This is currently supported by Win95 and WinNT. It's useful when doing backups from Win95 onto a CD-R, because the disc is still readable as ISO-9660 but shows the long filenames under Win95. The limit on Joliet filenames is 64 characters. (Some software reportedly allows up to 110.)

The spec can be found at http://www-plateau.cs.berkeley.edu/people/chaffee/jolspec.html.

Recent versions of Linux (kernel >= 2.0.34 and 2.1.60) have Joliet support. Older versions can be patched; for details, see http://www-plateau.cs.berkeley.edu/people/chaffee/joliet.html.

To patch Joliet support into OS/2, visit: http://service.software.ibm.com/os2ddpak/html/miscellb/os_2warp/updatedc/index.htm

For the Macintosh, use Joliet Volume Access (http://www.tempel.org/joliet/).

Some old Creative CD-ROM drivers have trouble with CD-ROMs that have Joliet filenames. You may need an updated copy of sbided95.exe. It used to be available from http://www.ctlsg.creaf.com/, but that site no longer exists.


Subject: [3-5-5] Romeo

Adaptec's Easy-CD Pro software allowed creation of discs in "Romeo" format. Filenames may be up to 128 characters long, which is very useful for certain types of files. Sadly, this format never really caught on. NTI's CD-Maker software (section (6-1-12)) supports Romeo.

One person reported having trouble reading Romeo-format discs in Win2K, others have had no problems.


Subject: [3-5-6] ISO/IEC 13346 and ISO/IEC 13490

These are (relatively) new standards intended to replace ISO-9660. The UDF filesystem specification is based on ISO/IEC 13346 (which is closely related to ECMA-167). For more information about these standards, see the links in section (6-4).


Subject: [3-6] How do I use a CD-i disc on a PC?

Short answer: you don't, unless you have a CD-i add-on board. Even if you have a CD reader compatible with the CD-i (Green Book) standard, there are still a number of obstacles in your way. The filesystem used isn't ISO-9660, and CD-i players are based around a 680x0 CPU and have special hardware for video and audio.

Longer answer: it depends on what kind of disc it is, and what you mean by "use".

PhotoCD and VideoCD discs are CD-ROM/XA "Bridge Format" discs that play on CD-i players as well as dedicated players and computers. These use the ISO-9660 file system, and can be read with commonly available PhotoCD software and MPEG-1 players.

DigitalVideo discs from Philips manufactured before June, 1994 are in CD-i format, not VideoCD format. If your CD-ROM drive supports raw 2352-byte sector reads, it's possible to pull tracks off of a Green Book format disc, and extract audio or MPEG video data. You can get a CD-i filesystem for Windows from http://www.icdia.org/articles/filesystem.html.

VCD PowerPlayer from CyberLink (http://www.cyberlink.com.tw/) can play CD-i movies directly off of a Green Book disc.

In-depth information is available from http://www.icdia.org/.


Subject: [3-7] How can I extract disc and track titles from an audio CD?

Typical Red Book audio CDs don't have this information. Software audio CD players like those provided by Adaptec or Microsoft require you to type in the information, which is then stored in a database on your hard drive. The discs are identified by computing a signature based on track offsets and other fields. http://www.cddb.com/ acts as an Internet database of CD info.

Some newer formats, like CD Extra, allow or even require such information to be included on the CD. See Sony's pages at http://www.cdextra.com/.

Some recent CD players are advertised as "CD-Text Ready". These use the CD-Text data embedded in the P-W subcode channels to display disc and track title data. See section (3-28) for more about CD-Text.


Subject: [3-8] How do I write more than 74 minutes of audio or 650MB of data?

CD-R's have a pre-formed spiral track, and the sector addresses are hard-coded into CD-R media, so there's no flexibility. Every disc holds a predetermined amount of data.

Most discs rated at 74 minutes hold slightly more than that. How much more depends on the brand of media, batch of media, and perhaps even on the recorder used (see section (7-6) for more details on how much a CD-R can hold). In some situations you can exceed the stated capacity of the disc; see section (3-8-3) below.

Since CDs are written in a spiral, the amount of data you can get on a disc is affected by how tightly spaced the "groove" is. A standard Red Book audio CD or Yellow Book CD-ROM is designed to allow at most 74 minutes of data. By using a tighter track pitch on the spiral "groove" on the glass master, manufacturers can get more data onto the disc. In theory this could make it harder for some CD readers to use the discs. See section (3-8-1) for notes on 80-minute discs.

The easiest way to get more data onto a disc is not to try. For audio CDs, you can leave off one or two tracks that you're not overly fond of. For data CDs you may be able to drop some images or sample data. The most common problem people encounter with data CDs is trying to copy them as a collection of files rather than doing a bulk copy of the entire disc. See also section (3-24).

One user suggested using the "speed up" function of SoundForge or CoolEdit to increase the speed of extracted WAV files by 3%. This supposedly gives better results than resampling, and allows writing 77 minutes of audio onto a 74-minute disc.

If you have a mono recording, you could double the length of a CD by recording half the sound on the left track and half on the right. The sound would be recorded as two monaural files, and then merged into a single stereo file with a sound editor like Cool Edit. (With Cool Edit 96: load first mono file. Use "Convert Sample Type" to convert to Stereo. Select the right track, and Delete Selection. Use Mix Paste to load the right track from the second file, or just fire up a second copy of Cool Edit with the other track, and use Copy and Paste commands.) The person playing the CD back will need to use a "balance" knob to select the left or right track. One issue with this method is that the track markers apply to both tracks, so providing random access to specific sections can be tricky.

If you're trying to copy a CD-ROM or VideoCD and running out of room, you may have a different problem. See sections (3-24) and (4-25).

Incidentally, don't get confused when you discover you have 700MB of audio extracted from a CD that only holds 650MB. Audio sectors use 2352 bytes per sector, while standard CD-ROM data uses 2048 (the rest is for error correction). You can put roughly 747MB of audio onto a disc that only holds 650MB of data.


Subject: [3-8-1] How well do 80-minute CD-R blank discs work?

In general, they work just fine. Reports from people who have used 80-minute CD-Rs indicate that compatibility with different CD-ROM drives is very good. However, bear in mind the following statement, which was sent by e-mail from a TDK representative:

"The CD-R80 is a special product developed by TDK to meet the application needs of software developers and music studios. To achieve its 80 minute recording time, track pitch and scanning velocity specification tolerances had to be minimized, reducing the margin of error between drive and media. This means limited compatibility between some CD-Recorders and CD-ROM Readers. If you intend to use this recording length, please check with your hardware manufacturer. Use of the CD-R80 is at one's own risk. No guarantees of performance are made by TDK."
Whether it's better to use 80-minute discs or "overburning" (described in the next section) is a worthy subject for debate. Both can cause problems on different CD-ROM drives, and not all recorders are capable of doing one or the other. Because of consumer demand, nearly all recent drives can do both.

An 80-minute disc has roughly 360,000 sectors instead of the usual 333,000. This increases the CD-ROM capacity from 650MB to 703MB.

If you're making backups of your hard drive or writing valuable data, don't use either. Stick to 74-minute blank discs, and only record as much as you're supposed to. CD-R media is too inexpensive these days to justify pushing the limits for a slight increase in storage. Long-term reliability is the most important factor in backup media.


Here's a few personal notes on my experiments with TDK 80-minute "green" blank discs, back in late 1997. Similar discs are now commonly available in most retailers, often for the same price as 74-minute media. Back then this wasn't the case, but I was able to purchase a small quantity (three discs) from Microboards at http://www.microboards.com/. This is rather outdated now, but I'm leaving it in as a historical footnote.

The discs were part number SCWA-ETC80A-X, priced at US$40.00 per disc in October 1997. That was about 20x the cost for an extra 8% storage. The discs were unbranded. The only difference I could see between these and other TDK green discs is that on the hub it says "CD-Recordable 6129B-80". Easy CD Creator Deluxe v3 showed 359,624 blocks (702.8MB in MODE-1) on the TDK 80-minute blank discs, versus 333,010 blocks (650.8MB) available on my Mitsui gold 74-minute blank discs.

The first challenge was finding software that would work correctly with the discs. Neither Easy-CD Pro 95 v1.2 nor Easy CD Creator Deluxe v3.0 would allow me to do a test recording with more than 650MB of files. I ended up using mkisofs to create an image file with 341,163 blocks (666.3MB) of data, composed of two large .AVI files, and three smaller pieces of one of the other .AVI files. (With Easy CD Creator Deluxe v3.5 and later, you can choose to ignore a warning about the data size.)

Using a Yamaha CDR-102 with v1.0 firmware, the first thing I tried was to burn the image file to a 74-minute blank. Easy-CD immediately rejected the disc, saying there wasn't enough space. I then put the 80-minute blank in and did a test run. Easy-CD Pro 95 had no problems burning the ISO-9660 image file, until the screen saver activated and McAfee anti-virus "screen scan" kicked in. Good thing it was a test burn; I got a buffer underrun. I killed the screen saver and virus checker and ran again, had a successful test run, and followed it with a successful burn.

To verify the data, I used Easy-CD Pro 95's "compare track" feature. This failed, complaining that one track was shorter than the other. My guess is that the compare feature has some sort of track length limitation. My next attempt was to use the Linux "sum" command to make sure that the disc was readable in my Plextor 8Plex. This worked fine, and the output of "sum" matched what I got on the 4x CD-ROM drive in the Sun workstation at work. I also tried the disc in a Mac 7500 and a Dell Pentium, and had no problems with either.

The next step was an 80-minute audio CD, and that's where things fell apart. Easy-CD Pro 95 v1.2 didn't work at all (!), Easy CD Creator Deluxe v3.0 again refused to allow me to create a long audio CD, and with Jeff Arnold's software (both the DOS version and CDRWIN) the test write failed after a minute or so (after the lead-in had completed?). Strangely, removing the last two tracks from the cue sheet, which reduced it to 72 minutes, allowed the test write to succeed on both 74-minute and 80-minute blank discs. It appears that the Yamaha CDR-102 drive is unwilling to write that much audio data.


Subject: [3-8-2] How well do 90-minute and 99-minute CD-R blank discs work?

Small quantities of 90-minute and 99-minute blank discs have appeared, but since their introduction in late 2000 they haven't become as commonplace as other lengths. Indications are that many recorders and some software don't really work with the longer discs.

The discs have capacity of roughly 791MB (90 min) and 870MB (99 min). However, all the capacity in the world won't help you if you can't read the disc back. If you're interested in larger but incompatible discs, and don't want to pay the premium imposed by DVD-R, read about DD-R/DD-RW in section (2-37) and ML in section (2-39).

CD time stamps are two digits (binary coded decimal, in case you were wondering), so exceeding 99 minutes isn't possible. You could, in theory, declare there to be 99 seconds in a minute and 99 sectors per second, but that would break just about everything that tried to read one. The limits of the specifications are being pushed at 80 minutes and even harder at 90, so don't expect much more out of CD-R. Some knowledgeable individuals have stated that the longest possible CD-R is 79 minutes, 59 seconds, 74 blocks long, because of the way that the last possible start time of the lead-out is encoded, but you can use "overburning" (discussed in the next section) to write past that point.

See http://www.mmore.com/download/Technical_write-up-MMORE_90_min.pdf for a tutorial on burning 90-minute discs with Nero. In short: make sure your drive supports overburning, set "Enable overburn" in the "Expert features" tab of the preferences, ignore the warnings, and cross your fingers. Always verify the disc afterward.


Subject: [3-8-3] How can I exceed the stated disc capacity ("overburning")?

The capacity of a CD-R is calculated to allow enough space to hold at least 74 minutes of Red Book audio data and 90 seconds of digital silence. The silent area is called the "lead-out", and is included so that a CD player will realize that it has reached the end of the disc, especially when fast-forwarding.

When a recording program tells you the exact capacity of the disc, it's not including the area reserved for the lead-out. There's nothing magic about this reserved area though. With the right kind of setup -- and a willingness to accept write failures as a matter of course -- you can put data into the reserved area, and possibly into a few blocks past the end of it. This is often referred to as "overburning" a disc.

How much more you can fit depends almost entirely on the media. Some brands will hold as much as 78 minutes, but it varies from batch to batch. You can use Feurio! (section (6-1-42)) to compute the maximum size of a specific disc without actually writing anything on it.

You also need the right recorder and the right software. The Teac CD-R55S, Plextor PX-R412C, Yamaha 4xx/4xxx, and Memorex/Dysan CRW-1622 units have been used to write "extra long" audio discs successfully. The Philips 36xx, HP 71xx, and Ricoh 62xx units don't seem to be willing to do so. In some cases, getting the firmware revision may be important. A recorder that isn't able to do this sort of writing will usually reject the cue sheet before writing begins.

To write such a disc, you need to use a program that won't refuse to exceed the disc capacity. Easy CD Creator, in an attempt to prevent you from making mistakes, will refuse to allow you to write more than you should be able to. CDRWIN will warn you that the write may fail, but will allow you to continue anyway. Nero has a preference (under Expert Features) called "enable oversize disc" that allows the longer write.

One approach to determining the maximum disc length is to gather a large collection of audio tracks, and start writing. Eventually the recorder will attempt to write past the end of the disc, and the write process will fail. Now play the disc, preferrably in a player that shows the total elapsed time for the entire disc. When the music cuts off, make a note of the time. That's the absolute capacity of the disc.

Most (all?) CD players will display the total disc time when you first put the disc in. This value represents how much you tried to write, not how much was actually written. If you want to impress your friends, try to write 88 minutes of music. You won't get anywhere near that far on 74-minute media, but the CD player will show it.

It should be possible to write a CD-ROM in the same manner as an audio CD, but the space would have to be calculated so that the write failure occurred when the lead-out was being written. Otherwise, some of the files that appeared to be on the disc wouldn't actually exist.

Recording in DAO mode may be helpful to ensure that the lead-in gets written. Without a table of contents, the disc is useless. It's very likely however that you will be able to finalize the disc even after the write fails.

Depending on the disc and your player, you may have trouble seeking out to tracks near the end of the disc. Also, your CD player may behave strangely when it walks off the end of the disc: one user said he had to open and close the player afterward to convince it that a disc was still loaded.

The disc surface past the end of the area reserved for the leadout may be unreliable. Attempting to use more than 90 seconds (about 15MB of MODE-1 data) beyond the rated capacity of a disc could be asking for trouble.

It's possible to perform similar tricks on 80-minute media. Experiments with TDK 80-minute discs resulted in a recorded length of 82:09. MMC recorders don't seem to like having the lead-out position any later than 88:29:74, but that shouldn't get in the way.

Further commentary and instructions can be found at http://www.cdmediaworld.com/ under "OverSize / OverBurn CD-Rs", including a list of recorders that are known to work and step-by-step instructions for using popular software.


Subject: [3-9] How do I put photographs onto CD-ROM?

The first thing you have to do is get them onto your computer. There are three basic approaches: use a scanner to convert printed photographs, use a video digitizer to pull images off of a video tape, or use a digital camera to take pictures that can be transferred directly.

There are a great many different scanners, with different resolutions and capabilities. http://www.zdnet.com/special/filters/sc/scanner/ is a fair place to start. (If the link doesn't work, go to zdnet.com and look for reviews of scanners.)

Video digitizers are mentioned in section (3-16). If you're scanning off of VHS video tape, you are going to get disappointing results.

Digital cameras will generally give you the best results. A mid-range digital camera will give you pictures that look as good (when printed on a photo-quality printer, which are inexpensive now) as a 35mm point-and-shoot film camera. A few links:

Once you have the photograph on your hard drive, you may want to touch it up a bit. You can use software to correct for over- and under-exposed snapshots, remove "red eye", and crop off bits that weren't supposed to be in the frame. Cameras and scanners should come with image manipulation software that will help you manipulate and manage the images. Adobe's PhotoShop (http://www.adobe.com/) is the standard high-end solution, and their PhotoDeluxe Home Edition may appeal to a less demanding crowd.

Once you've got the images in a reasonable state, save them in a widely accepted format such as JPEG or TIFF, and write them to a CD-ROM like you would any other files. You may need to use an "Export" function rather than "Save As...", because consumer photo software authors tend to use proprietary image formats as the default.

If you want to create a PhotoCD that can be played in a PhotoCD player, continue on to the next section. If you're interested in arranging the pictures into an album, see (3-9-2).


Subject: [3-9-1] How do I create a PhotoCD?

First off, you need to be aware that certain aspects of PhotoCD creation are proprietary to Kodak. Programs like Roxio's Easy CD Creator will allow you to create CD-ROMs with PhotoCD image files, and you will be able to view the images with Mac or PC programs that understand the PhotoCD file format, but you won't be able to look at the disc with a PhotoCD player.

http://www.kodak.com/country/US/en/corp/pressReleases/pr19950328-10.shtml has the glossy brochure information, with some Kodak contact information. The Build-It and Arrange-It software, which allow you to create "real" PhotoCDs, costs about US$450. Kodak apparently pulled the software from the market in December 1997, so it may be difficult to find.

http://www.shiresoft.com/ gives you step-by-step instructions and software for creating "real" PhotoCD discs with Kodak's software. The Build-It program will only write to Kodak CD recorders, but a translator available from this web site will allow it to work with GEAR or CDRWIN. Follow the Kodak links on that page.

There are some utilities that will convert images into PCD format, but they only support the uncompressed base resolutions. The higher resolutions are compressed with an algorithm proprietary to Kodak.


Subject: [3-9-2] How can I set up a photo album on CD-ROM?

There are programs available that will do this for you, or you can take a "do it yourself" approach. Some examples:

Roxio "Photo Relay" (part of Easy CD Creator Deluxe Edition - see section (6-1-26)). According to their web page, it "lets you organize digitized photos and videos, then create Slide Shows, Web Albums and Video Postcards that can be stored to CD and shared with others - no proprietary viewer is required by the recipient!".

Cerious "Thumb's Plus" (http://www.cerious.com/). Helps you organize images and create slide shows. Free evaluation version.

Firehand "Lightning" (http://www.firehand.com/lightning/). Photo albums, slide shows, screen savers. Free evaluation version.

Tlonstruct "CDView Pro" (http://tlonstruct.com/). Fancy picture viewer. Free shareware download.

G&A Imaging "PhotoRecall" (http://www.ga-imaging.com/). Commercial program with lots of features.

InMedia "Slides & Sounds" (http://www.inmediapresents.com/slideshows.html). Create fancy presentations. Demo available.

Extensis "Portfolio" (http://www.extensis.com/portfolio/). Heavy-duty software for "media asset management". Supports every file format you've ever heard of, and has support for hybrid CD recording.

The do-it-yourself approach. Make an HTML page with pictures, using a program like Microsoft FrontPage to create thumbnails (the auto-thumbnail feature is *very* handy), so that when you click on the thumbnail image you get the full-sized image. Put the HTML page and all of the graphics onto a CD-ROM, and view the pictures with a web browser. For bonus points you can use "shellout" with autorun.inf (section (3-21)) to have Windows automatically launch the default web browser when the disc is inserted, and "mkhybrid" to create a disc with long filenames and correct file types for Rock Ridge, Joliet, and MacOS.

The "Film Factory" software that comes with some Epson printers has an "export to web page" function that works pretty well. The "lite" version that comes with their greeting card paper may or may not support this feature.


Subject: [3-9-3] How can I show digital photos on my DVD player?

The easiest way is to use a program that does it for you. Ulead's "DVD PictureShow" will create VideoCD or DVD discs with your photos on them. More information is available at http://www.ulead.com/. A similar product is PictureToTV from http://www.picturetotv.com/.

The first step is to make sure your DVD player can play CD-R media. Create an audio CD on CD-R media, put it into your DVD player, and try to play it. If it works, great. If it doesn't, try the experiment again, this time with CD-RW media. If neither works, or CD-R doesn't work and you can't record CD-RW discs, you're out of luck. See section (2-13) for more about DVD players and compatibility.

The next step is to find a way to display the photos. Some DVD players can display PhotoCD discs, but there isn't a way to create "real" PhotoCD discs with currently available software (see section (3-9-1)).

The alternative is to create a VideoCD with still frames. Each still frame is a medium sized (704x480 in NTSC) JPEG image. By gathering these into a collection, you can create a VideoCD "slide show" that will play on most DVD players. Be careful though: a fair percentage of DVD players do not support VideoCD. You should be able to figure this out by looking through the manual. If no reference to VideoCD can be found, you'll just have to try it and see.

See section (3-16-1) for more about VideoCD.

The MPV (MultiPhoto/Video) specification was announced in November 2002. It's purpose is to define a standard way of storing pictures, videos, and audio on digital media. This should allow you to create discs with multimedia content easily and display them on compatible DVD players. See http://www.osta.org/mpv/.


Subject: [3-10] How do I make a CD that will work on a PC or a Mac?

[ Moved to section (3-35). ]


Subject: [3-11] How do I access different sessions on a multi-session CD?

As always, it depends.

MS-DOS lets you see the first data session. Usually. Win95 lets you see the last data session. Usually. Roxio's Session Selector and Ahead's MultiMounter will let you choose which session you see.

Some CD creation software (e.g. Roxio Easy CD Creator) writes a complete table of contents in each session, some of which refers back to the files from the previous session, allowing a form of incremental backup. (This will work for ISO-9660 discs, but won't work for HFS. However, this is less painful than it seems because a properly-configured Macintosh will let you mount all the sessions as individual volumes.)

Roxio's Easy CD Creator will allow you to combine the contents of several previous sessions by creating a new session (load the file/directory info from more than one session, then write and close a new session with that directory structure).

Some of it depends on the SCSI or CD-ROM driver you have installed. It's unwise to expect somebody else's system to treat multisession discs the same way yours does.


Subject: [3-12] How do I transfer my records or cassettes to a CD?

Conversion of cassette tapes and vinyl records is increasingly popular. Common reasons range from plans for long-term preservation to a desire to listen to old favorites while driving in a car without a tape player.

There are two basic kinds of CD recorders: those that attach to a computer, and those that stand alone. The latter, described in detail in section (5-12), are usually connected to a stereo system. They are easier to work with, but less flexible.

The first step, regardless of equipment, is figuring out how to physically connect your tape player, turntable, or wax cylinder player to something else. You almost always want "line-level" sound. The output from a turntable is typically not line-level, so it has to be connected to a receiver or pre-amplifier "phono" input. You then use the outputs from the receiver or amplifier; if you can find outputs labeled "tape out" or "preamp out", use those.

(A pre-amplifier raises the voltage level from the phono cartridge up to "line level" voltage. An amplifier increases the signal from line level to whatever is needed for your speakers. A pre-amplifier will also compensate for pre-emphasis in the recorded material.)

You could connect your recorder to the headphone jack on the receiver or amplifier, but that's not the best way to go. The voltage level coming out of the headphone jack varies on the volume setting, while line-level output doesn't. This makes line-level easier to set up. If all you can find is a headphone jack, you will have to fiddle with the volume control until the sound is as loud as possible without "clipping". If one of your devices has little colored bars that bounce up and down according to how loud the sound is, you need to play something "loud" on your tape player or turntable, and adjust the volume until the loudest parts rise up just shy of the maximum.

Connect the output from your tape player, receiver, or amplifier into the CD recorder (if you have a stand-alone model) or the "line in" on the sound card on your computer (if you're using that). Continue with section (3-12-1) if you have a stand-alone model, section (3-12-2) if yours is attached to a computer.


You can find odd bits of hardware that will play or enhance playback of older recording formats (78's, LP's, 16" Radio Transcriptions) at Nauck's Vintage Records (http://www.78rpm.com/).

For those of you wondering what the deal with pre-emphasis is, this little tidbit is courtesy Mike Richter:

"Preemphasis has been used since the earliest days of commercial recording. In general, the high-frequency content of the music (or whatever) being recorded is low and the noise is high. Therefore, treble was boosted and lows were cut by a preemphasis curve which was removed in playback. The standard RIAA curve for turnover and rolloff (the amount and frequency for treble and bass, respectively) was not accepted universally until the 50's, and some fine preamps offered selectable values with presets for the common curves into the early transistor era."

 

Subject: [3-12-1] ...with a stand-alone audio CD recorder?

Once you've got everything hooked up, hit "record" on the CD recorder and "play" on the other device. Wait a while. You're done.

You may want to fiddle with it to mark the start individual tracks. See the instructions that came with your recorder.


Subject: [3-12-2] ...with a CD recorder attached to my computer?

Recording into a PC is a little trickier, but you have much more control over the final result. It's easy to edit away silence and reduce or remove clicks and hissing.

In addition to the material here, you may want to read these tutorials:

http://www.delback.co.uk/lp-cdr.htm
http://www.ganymede.hemscott.net/tutorial.htm
http://www.octave.com/library/outsidesource.html
The page at http://www.octave.com/library/audiocd.html is also useful.


The most crucial component is the sound card. The sound card converts the audio signal from analog to digital (an "A/D conversion"). Some cards do this conversion better than others. You can use the A/D converter built into a sound card like a SoundBlaster 16, but the sound quality will not be very good. The sound cards from Turtle Beach (Tropez, Tahiti) and CrystaLake are a step up, and a Digital Audio Labs CardD+ is about as good as it gets for internal A/D cards. If you're really serious, you should get an external A/D converter like the Symetrix 620 or the Lucid AD9624 and feed the digital output from that into the computer. (Looks like the Lucid device has superseded the Symetrix one -- it's the same company. Relevant URLs are http://www.symetrixaudio.com/ and http://www.lucidtechnology.com/.) Other products can be found at http://www.midiman.com/.

Another way of accomplishing the same thing is to record to an audio DAT deck and then use the digital output on the DAT recorder; see section (3-13) for details. With some decks, such as the TASCAM DA-20 mkII and DA-302, it's not even necessary to record to tape. You can play straight through the recorder.

A problem with some sound cards (really cheap Opti and ESS cards have been named) is that the crystal that controls the recording sample rate is off. If the card doesn't do the sampling at the correct rate, the recorded audio may end up slightly slower or faster than the original. This will become apparent when the sound is played back off of a CD or through a better sound card. Most sounds cards don't have this problem.

If you have questions or need a recommendation on a sound card, you might want to try:

news:rec.audio.tech
news:comp.sys.ibm.pc.soundcard.tech
Some highly technical benchmark evaluations of cards are available at http://www.rockpark.com/soundcards/ and http://www.pcavtech.com/.

Roxio's Easy CD Creator (section (6-1-26)) includes an application called "Spin Doctor" that performs most of the tasks needed to transfer LPs to CD. Depending on your needs, it may provide a simple all-in-one solution.

A simpler approach is to use a program capable of recording large amounts of audio from the sound card. Cool Edit 2000 (section (6-2-14)) works nicely. Whatever you choose, you should again play a loud passage and watch the "VU meter" display to make sure you're getting as much signal as you can without clipping. If the little colored bars are slamming against the top, you're clipping. The Windows volume control panel (double-click on the yellow speaker icon in the lower-right-hand corner) has a VU meter in it, and allows you to set the input gain.

Configure the application to record 44.1KHz 16-bit stereo sound, click "record", hit "play" on your tape player or turntable, and wait a while. When the music is done, stop the recording on the computer. You can either record the result directly to a CD, or clean it up a bit first. See the next section for some suggestions.

Bear in mind that CD-quality audio uses up about 10MB of disk space per minute, so one side of a 45-minute tape will require roughly 450MB. Make sure you have enough disk space before you start.


Subject: [3-12-3] How can I clean up the audio before recording?

There are a variety of programs that can automatically remove pops, clicks, and hissing from digitized audio. Few automated tools can do as good a job cleaning up pops and other noise as an experienced person, however. If you want to perform the transfer by hand, the following method has been suggested for PC users with Cool Edit:

  • Record directly into Cool Edit, using the highest possible input level that doesn't exceed the maximum. You want to record 16-bit stereo samples at 44.1KHz.
  • In the "noise reduction" dialog, set FFT size to 8192, FFT precision to 10, and #of samples to 96.
  • Select a silent passage between songs or from the end of the record. It can have some crackling but no huge pops. Set the noise level.
  • Select the entire track and perform noise reduction at about 70%.
  • Select the entire track and normalize it.
  • Manually remove any big pops (easily located by zooming in to the general area and switching to "spectral view" in the edit menu) by zooming in on them and amplifying them to about 8%. You only need to select the channel (left or right) in which the offending data occurs. If it occurs across BOTH channels, you may get a better result by deleting that part of the track and reconstructing it in such a way that it remains smooth... if that's not possible, make one channel smooth and then amplify the other to 8%.
Cool Edit optionally leaves a blob of data at the end of the .WAV file, which is legal in the file format but not expected by some utilities. To avoid this, make sure the "Save extra non-audio information" box isn't checked.

Software that may come in handy:

Cool Edit 2000
http://www.syntrillium.com/, nice audio editor. A plugin is available that does hiss and click removal; for a review, see http://www.plompy.co.uk/music/digital_audio.html#cool
GoldWave
http://www.goldwave.com/, similar to Cool Edit.
Clean! plus
http://www.steinberg.net/products/, designed for vinyl and tape xfers.
Sound Forge
http://www.sonicfoundry.com/, fancy commercial product with lots of plug-ins.
Algorithmix
http://www.algorithmix.com/, has a noise reduction program called SoundLaundry.
DART and DART PRO
http://www.dartpro.com/, designed for audio restoration ("click removal" and more).
DCart
http://www.diamondcut.com/, audio restoration.
Pristine Sounds 2000
http://www.alienconnections.com/, audio restoration.
Gnome Wave Cleaner
http://gwc.sourceforge.net/, audio cleanup under Linux.
Waves software (various)
http://www.waves.com/, fancy (and expensive) audio manipulation.
CD Wave
http://www.cdwave.com/, useful for splitting a single large WAV file on track boundaries.
Wave Repair, from http://www.waverepair.com/, is a WAV editor designed with analog recording and click-fixing in mind. It's aimed at very flexible manual repair with some helpful automation. If you'd like something a little heavier on automation and a little lighter on manual control, try Wave Corrector at http://www.ganymede.hemscott.net/wavecor.htm.

Don't forget that CD audio is 16-bit PCM stereo samples at 44.1KHz, and will chew up disk space at roughly 176K per second. Playing back large sound files is difficult with simple-minded applications like the standard Win95 sound player, because they try to load the entire file into memory all at once. Cool Edit 2000 is able to play files back as it reads them, and works very well even over a network. (Section (4-20) has some other suggestions on this same topic.)

See section (3-3) for some tips on avoiding clicks when committing the audio to CD.

If, for some reason, you'd like to record "live" to the CD-R instead of recording to the hard drive first, see section (3-54).


Subject: [3-13] How do I transfer an audio DAT tape to CD?

Buy a card that will allow you to go from DAT to hard disk digitally. Make sure you get one that can handle the same digital standard the DAT recorder uses, i.e. S/PDIF (Sony/Phillips Digital Interface Format, sometimes referred to as "domestic") or AES/EBU ("professional").

Some of the solutions for the PC are:

The CardD+ comes highly recommended. There may be newer versions of these products, so be sure to check out the web sites.

Visit http://www.digitalexperience.com/cards.html for a feature comparison of many different models.

An inexpensive S/PDIF card available from Computer Geeks (http://www.compgeeks.com/) was evaluated by some newsgroup readers in mid-1998. Apparently there were some problems with the physical dimensions of the card (too wide for some PC slots), the documentation is poor, and the voltage level for both input and output was TTL instead of standard S/PDIF. You're probably better off with one of the established brands unless you're sure about what you need.

For technical information on S/PDIF, check out http://www.plompy.co.uk/music/digital_audio.html#cmedia.

You should record from the DAT onto your hard drive, and then record the CD from there. If you try to record directly from DAT you'll likely end up with a lot of wasted CD-Rs due to buffer underruns or minor mistakes. You should use Disc-At-Once recording for best results.

One issue you need to be aware of is that some older DAT recorders can only record at 48KHz, while CDs are recorded at 44.1KHz. If this is the case with your equipment, you will have to do a sample rate conversion. The DSP on cards like the ZA2 will do this for you, or you can use an audio editing program like Cool Edit or Sound Forge.

There *are* CD-R drives that have analog inputs, and can record directly from audio sources. See section (5-12).

If you use a DAT and haven't been to the DAT-heads home page, you should definitely check out http://www.atd.ucar.edu/rdp/dat-heads/.

If you want to manipulate audio DATs directly from your computer, you need a DDS drive with special firmware. The SCSI DDS drives that are typically sold for backups don't have the firmware required to handle DAT tapes. Most SGI workstations can do this, and Mac users should check out http://www.demon.co.uk/gallery/StudioDAT.html. If you have an Archive Python DDS drive, check out ftp://ftp.informatik.uni-erlangen.de/pub/DATlib. Reputable Systems (http://www.reputable.com/) sells DDS-2 drives with SGI firmware, Archive/Conner/Seagate model CTD-8000HS.

Some other drives can be supported with appropriate firmware updates. See http://www.ncf.ca/~aa571/dat2wav.htm.

An interesting combination of technologies is the DAT-Link from http://www.tc.com/, which connects to the digital connectors on the DAT machine (or MD, DCC, or CD player) and the SCSI interface on a computer. The device can be controlled from other computers on a network.

If you're interested in mastering production audio CDs, you should take a look at http://www.sadie.com/.


Subject: [3-14] How do I put audio and data on the same CD?

There are two ways to do this. The first is to put the data on track 1 of the CD, and audio on the next several tracks (discs created this way are referred to as "mixed-mode" CDs). The CD-ROM drive will automatically look at track 1 and ignore all other tracks, so you'll be able to get at the data and -- depending on the operating system -- will be able to play the audio tracks. Remember that all of the tracks, both audio and data, need to be recorded in a single session. See section (3-2).

The down side of this is that audio CD players may attempt to play track 1, which can be obnoxious or downright harmful to audio equipment. Most modern CD players are smart enough to ignore data tracks, so this won't usually be a problem.

The other approach is to create a multisession disc with the audio tracks in the first session and the data track in the second. This is how CD Extra (the format formerly known as CD Plus) works. Audio CD players only look at the first session, and CD-ROM drives are (supposed to) start with the last session, so it all works out. Sony Music has some pages at http://www.cdextra.com/.

(NOTE: it appears that in some situations a Macintosh will not handle multi-session audio/data CD-R discs correctly. For example, a G3 with a DVD-ROM drive running Mac OS 8.6 works fine, but a G4 or iMac running Mac OS 9 will reject the disc as unreadable. The same system will handle pressed discs correctly -- only CD-Rs fail. The reason for this is uncertain, but it may be possible to work around it by disabling the system's audio CD extension when you want to read the data portion.)

A common question is how to write the audio in the first session without gaps between tracks, because you can't use disc-at-once recording. (If you did use DAO recording, the disc would be closed, and you wouldn't be able to write the data track). With the right hardware and software, you can do "session-at-once" recording to write the audio without gaps. For example, if you're recording with Nero and SAO-capable hardware, you just select disc-at-once mode but don't select "finalize CD".

What happens when you try to play one of these as audio in your CD-ROM drive? As with most things multisession, it depends on your drive. (The player that comes with Plextor CD-ROM drives does the right thing. If you're using a different drive, you're on your own.)


There's actually a third way to do this that involves putting the data track into the extended pregap of the first audio track. Instead of the audio starting at minute:second:block 00:02:00, the data starts there, and the audio is written after. The pregap is adjusted accordingly. This method never gained popularity because some drives started playing at 00:02:00 regardless.

Some CDs perversely put audio in the pregap. You can play it by starting to play track 1, then holding the "reverse" button until it seeks all the way to the start of the disc. Some older digital audio extraction programs would just ignore the "hidden" audio, but most newer ones will extract the entire track.

For example, _Factory Showroom_ by "They Might Be Giants" looks like this:

TRACK 01 AUDIO
INDEX 00 00:00:00
INDEX 01 01:01:00
TRACK 02 AUDIO
INDEX 00 04:52:10
INDEX 01 04:52:10
TRACK 03 AUDIO
[...]
Index 01 on track 01 is usually 00:02:00. Holding down the reverse button backs the time up to -1:03. This disc actually causes one of my Windows machines (Win98SE with a Plextor 12/20 CD-ROM) to read the disc incessantly, making it impossible to play the disc or extract audio tracks.

See section (3-36) for more information on "hiding" audio tracks.


Subject: [3-15] How do I make a bootable CD-ROM?

On a Mac, this is reasonably straightforward. A CD can be bootable if it has a bootable system folder on it. Tell the recording software that you want to make the CD bootable; this usually involves clicking in a checkbox before burning the first session. Then, copy a bootable system folder onto the disc. An easy way to create an appropriate system folder is to launch the system installer, tell it you want to do a "Custom" install, choose the "Universal System" option, and then install it onto the CD source volume. One caveat: any control panels or extensions that want to write to their preferences files will fail. You may need to write from a system folder that has been booted at least once.

Detailed instructions for creating a bootable CD with Toast can be found at http://www.roxio.com/en/support/toast/toastbootable.html.

Holding down the 'c' key while booting will cause the Mac to boot from an internal CD-ROM drive. Alternatively, the "Startup Disk" control panel will allow you to select a CD-ROM.

The rest of the section applies only to PCs, which are more challenging.


The BIOS or SCSI card on most newer machines support booting from CD-ROM, but on many older machines it's just not possible. Phoenix (the BIOS developer) and IBM have created the El Torito standard for doing this sort of thing. When the machine boots, if the BIOS recognizes a bootable image on the CD-ROM, it maps that image onto the A: floppy drive. (Depending on implementation, A: will move to B: and B: will go away.) From that point onward, it's just like booting a floppy.

Not surprisingly, the way you create a bootable CD-ROM is to take an image of a bootable floppy disk and write it in a specific way onto the CD. Many of the current CD writing programs, including Easy CD Creator and CDRWIN, will do the hard work for you.

A very nice page with lots of technical and how-to information:

http://www.nu2.nu/bootcd/
You can find El Torito specifications and a "how to" guide at:
http://www.phoenix.com/products/specs.html
http://www.phoenix.com/products/wp.html
If you like to do things the hard way, step-by-step procedures with varying levels of detail can be found here:
http://www.cdpage.com/Compact_Disc_Variations/bootablecdarticle.htm
http://www.ozemail.com/~rossstew/drs/bootcd.html
http://goldentimes.net/bootcd01.htm
http://www.fadden.com/doc/bootcd.txt
You can learn how to make bootable Win95b/Win98 CD-ROMs here:
http://www.heise.de/ct/Service/English.htm/99/11/206/
When booting the PC, you may need to change the boot order in the BIOS from the typical "A, C" to "A, SCSI, C", and configure the SCSI interface to attempt to boot from CD. On some adapters, the boot-up SCSI bus scan may take an extra second or two while the interface tries to determine if a bootable CD-ROM is present.

Some programs insist that bootable CD-ROMs be written in plain ISO-9660 format, not Joliet. One way around this is to write the bootable portion in the first session, and then write the rest of the data in a second session. However, not all PCs will boot a multisession disc. A better approach is to use a program like mkisofs (6-1-10) to create the image.

The El Torito standard allows CD-ROMs to have more than one bootable image, but few applications support creating such images. You can use mkisofs with the "-eltorito-alt-boot" option to do this.

If you're having trouble finding drivers for your CD-ROM drive, try the Win98 boot disk, or http://www.drivershq.com/.


Subject: [3-16] How do I convert home movies into video on CD?

This topic is largely outside the scope of this FAQ, so I'm not going to go into much depth. The Usenet newsgroup news:rec.desktop.video is more applicable. I'm not aware of an FAQ for that group, but the links found at http://www.videoguys.com/jump.htm will get you started.

You need a capture device to transfer the video to your hard drive. Capturing high-quality video can eat up 2MB or more per *second* of video at full resolution (640x480x24 at 60 fields per second for NTSC) with a reasonable degree of compression, so this isn't something to be undertaken lightly. The lower your quality requirements, the lower the bandwidth requirements. On a fast machine, you can even get away with just a TV tuner card, using the software from http://www.winvcr.com/.

If MPEG is your only interest, you might be better off with an MPEG-only card rather than a hobbyist video capture board. http://www.b-way.com/ and http://www.darvision.com/ are good places to look. The Broadway card has been given high marks for quality.

Once you've captured the video, you'll probably want to edit it, at least to clip out unwanted portions or add titles. Packages for doing this, like Adobe Premiere and Ulead MediaStudio, are usually included with the capture card. These will also let you adjust the resolution, color depth, and compression quality to output the video so that it's suitable for playback on double- or quad-speed CD-ROM drives.

You can convert AVI files to MPEG and vice-versa with a program from Ulead (see http://www.ulead.com/), Xing Technologies, or several other vendors. You should be able to create QuickTime or AVI movies using the compression codec of your choice from the video editing software. A good choice is TMPGEncoder, from http://www.tmpgenc.com/e_main.html.

Once created, you can write the AVI, MPEG, or MOV (QuickTime) file to a CD-ROM like you would anything else. If you'd like to view the disc in a DVD player or other VideoCD playback device, read the next section. Note that not all DVD players are capable of reading CD-R media, so if VideoCD on CD-R playback is important to you, check the DVD player feature set before you buy.

Converting directly to DVD format is pretty reasonable now, with relatively inexpensive DVD-R recorders and authoring software. Some Macintoshes ship with iMovie/iDVD and a DVD recorder built in.

The MPV (MultiPhoto/Video) specification was announced in November 2002. It's purpose is to define a standard way of storing pictures, videos, and audio on digital media. This could eventually be the preferred way to store movies on a disc. See http://www.osta.org/mpv/.


Subject: [3-16-1] How do I create a VideoCD from AVI or MPEG files?

This section assumes you already have the video captured on the hard drive of your computer. If you don't know how to do that, read the previous section.

The goal is to create a White Book VideoCD, which can be viewed on any VideoCD-compatible playback device. Most PCs and Macs have some amount of support, as do many DVD players, so even if you can't find a dedicated VideoCD player or CD-i box you should be able to find a way to watch them.

VideoCDs can only be read by CD-ROM drives capable of reading CD-ROM/XA discs. If your drive doesn't claim to support PhotoCD, you're probably out of luck, but this is rare. Microsoft's ActiveMovie (now Windows Media Architecture) and Apple's Video Player can play movies off of a VideoCD. Depending on the software you have installed, you may get a nice player, or you may need to examine the disc manually and open the ".dat" files in the "mpegav" directory.

If you were hoping to play your VideoCD on a DVD player, you should read about VideoCD and CD-R/CD-RW compatibility with DVD players first. See http://www.dvddemystified.com/dvdfaq.html#2.4.5 and section (2-13).

CD-R software packages like Easy CD Creator, Nero, and GEAR can write MPEG-1 movies onto a CD in the necessary format. You have to be careful when creating the MPEGs, because if the encoding parameters (frame rate, number of pixels, etc) don't match the VideoCD parameters you may have trouble getting the CD writing software to accept the movie.

You can include still frames from JPEG images as well. Most VideoCD creation software provides a way to organize "assets"

John Schlichther's "avi2vcd" combines standard tools into an easy-to-use program for Win95 and NT. You can use it to convert an AVI file into a VideoCD-compatible stream. http://www.mnsi.net/~jschlic1/.

Another choice is TMPGEncoder, from http://www.tmpgenc.com/e_main.html.

If you're running Linux you should take a look at Bernhard Schwall's "avi2yuv" program. It converts M-JPEG movies created with popular video capture boards into a format accepted by the Berkeley MPEG-1 and MPEG-2 encoders (ftp://bmrc.berkeley.edu/pub/mpeg/). The README for avi2yuv lists the additional software packages (all of which are free and run under Linux) needed for creating MPEG movies complete with sound. Most (all?) of the utilities can also be built to run under DOS. http://sunsite.unc.edu/pub/Linux/apps/graphics/convert/.

"iFilmEdit", from http://www.cinax.com/Products/ifilmedit.html, will convert MPEG to VideoCD, and can reportedly convert a VideoCD .DAT file back into a plain MPEG file.

"VCDGear", from http://www.vcdgear.com/, converts between .dat and .mpg.

http://www.vcdhelp.com/ has software and information.

The "VideoCD Cook Book" at http://www.flexion.org/video/VideoCD/0.html is worth a look.

Easy CD Creator, as of v3.x, requires that an MPEG MCI driver be installed in the system (unlike CD Creator, it doesn't come with Xing's MPEG software). The popular VMPEG 1.7 doesn't quite work: ECDC can't see the audio, and you're not allowed to select the frame to view when shuffling streams around. If you have VMPEG installed as the MCI driver -- select "About ECDC" from the Help menu to check -- you need to *remove* VMPEG and then install ActiveMovie. (I removed under Win95 it by going into the Advanced section of the Multimedia control panel, expanding "Media Control Devices", selecting vmpegdll, and clicking on "Remove", but you may be able to use Add/Remove Programs instead.) ECDC v3.x was very picky about the video streams; v4.02 is much better.

Finally, you should be aware that MPEG playback is rather CPU intensive, and it's possible to create movies that don't play very well on slower machines (90MHz Pentium, 68K Macs) without hardware support. Machines built in 1997 or later shouldn't have trouble.


Subject: [3-16-2] How do I create an SVCD?

First, read about creating a VCD in section (3-16-1).

Next, read http://www.uwasa.fi/~f76998/video/svcd/overview/.

The links near the end of the document point to some pages with SVCD authoring instructions. Programs such as Nero Burning ROM (6-1-28) and Enreach I-Author (6-1-61) are able to create such discs.


Subject: [3-16-3] How do I create an AVCD?

Some discs have been produced that call themselves "AVCD", as in audio-video CD. For example, Kylie Minogue's "Fever" CD was released as a two-disc set in Asia. Disc one was the "Fever" audio CD, disc two had four VideoCD video tracks and five bonus audio tracks.

If you put disc two into a CD player, you would hear nothing for track 1 (which holds the VideoCD filesystem) or tracks 2 through 5 (the video data). If you fast-forwarded to track 6, you would hear music.

If you put disc two into a VideoCD player or compatible DVD player, you would be treated to the first video track. By skipping forward you could get to the later video tracks and eventually play the audio tracks.

This makes perfect sense until you try to figure out how the same audio track is being played on a CD player and on a VideoCD player. If you try to create a VideoCD with extra audio tracks, the VideoCD player will not find them.

The trick used by the AVCD publishers is to encode the audio tracks twice. The songs are present both as Red Book CD audio tracks and as VideoCD compressed audio. A directory called "CDDA" holds files with names like "AUDIO06.DAT" that contain compressed audio. Unlike the video tracks, these don't actually correspond to tracks on the disc.

To create such a disc, you would need VideoCD authoring software capable of incorporating audio tracks. You could then record the VideoCD while leaving the session open, and append the audio tracks using track-at-once recording. Better results would be obtained by writing the video and audio tracks with disc-at-once recording, but that might require a greater level of VideoCD support than most recording applications currently provide.

See section (3-16-1) for more tips on VideoCD.


Subject: [3-17] How can I burn several copies of the same disc simultaneously?

You can if you have several CD-R drives and the right software. Two examples are CD Rep from Prassi Software (section (6-1-21)) and DiscJuggler from Padus (section (6-1-27)).

Both products are SCSI multiplexors. You use your existing CD writing application (such as Easy-CD Pro 95) like you normally would, and the program sends the same commands to each of the CD-R drives. There are a number of limitations, notably that all devices must use the same command set and may need to have the same firmware revision. There may also be limits on the number of drives you can have attached at once.

DiscJuggler bills itself as "the professional CD Duplicator", CD Rep as "the ultimate professional recording solution". If you're interested in either of these, you should read the web pages for both, and compare the features available.

There are several hardware-based solutions to this, including CD-R units that support daisy-chaining, and control units that vary from the simple (a handful of units wired together) to the complex (robotic arms to move discs around). Most cost more than a Hyundai.

See http://www.cd-info.com/CDIC/Technology/CD-R/duplication.html for an overview of several different hardware solutions, or visit a vendor web page like http://www.princetondiskette.com/.


Subject: [3-18] Can I make copies of copies?

The following was part of an e-mail message from Jeff Arnold back in mid-1997:

"I do not recommend making "copies of copies" with SNAPSHOT. The reason this does not always work is because many CDROM readers do not perform error correction of the data when doing raw sectors reads. As a result, you end up with errors on the copy that may or may not be correctable. When you make a second-generation copy of the same disc, you will make a disc that has all of the errors of the first copy, plus all of the new errors from the second reading of the disc. The cumulative errors from multiple copies will result in a disc that is no longer readable."
This initially generated some confusion, so further explanation is needed. The heart of the problem is the way that that the data is read from the source device. When a program does "raw" sector reads, it gets the entire 2352-byte block, which includes the CD-ROM error correction data (ECC) for the sector. Instead of applying the ECC to the sector data, many drives just hand back the entire block, including any errors that couldn't be corrected by the first C1/C2 layer of error correction (see section (2-17)). When the block is written to the CD-R, the uncorrected errors are written along with it.

The problem can be avoided completely by using "cooked" reads and writes. Rather than create an exact duplicate of the 2352-byte source sector, cooked reads pull off the error-corrected 2048-byte sector. The CD recorder regenerates the appropriate error correction when the data is written.

Some drives and some software will error-correct the 2048 bytes of CD-ROM data read in "raw" mode. This limits the risk of generation loss to errors introduced in the ECC bytes. If the software also regenerates the ECC, it is effectively emulating "cooked" reads and writes in "raw" mode.

This begs the question, why not just use cooked writes all the time? First of all, some older recorders (e.g. Philips CDD2000 and HP4020i) didn't support cooked writes. (Some others will do cooked but can't do raw, e.g. the Pinnacle RCD-5040.) Second, not all discs use 2048-byte MODE-1 sectors. There is no true "cooked" mode for MODE-2 data tracks; even a block length of 2336 is considered raw, so using cooked reads won't prevent generation loss.

It is important to emphasize that the error correction included in the data sector is a *second* layer of protection. A clean original disc may well have no uncorrectable errors, and will yield an exact duplicate even when copying in "raw" mode. After a few generations, though, the duplicates are likely to suffer some generation loss.


The original version of this quote went on to comment that Plextor and Sony CD-ROM drives were not recommended for making copies of copies. The reason they were singled out is because they are the only drives that explicitly warned about this problem in their programming manuals. It is possible that *all* CD-ROM drives behave the same way. (In fact, it is arguably the correct behavior... you want raw data, you get raw data.)

The final answer to this question is, you can safely make copies of copies, so long as the disc is a MODE-1 CD-ROM and you're using "cooked" writes. Copies made with "raw" writes may suffer generation loss because of uncorrected errors.

Audio tracks don't have the second layer of ECC, and will be susceptible to the same generation loss as data discs duplicated in "raw" mode. Some drives may turn off some error-correcting features, such as dropped-sample interpolation, during digital audio extraction, or may only use them when extracting at 1x. If you want to find out what your drive is capable of, try extracting the same track from a CD several times at different speeds, then do a binary comparison on the results. PC owners can use the DOS "FC" command to do this, as described in section (3-3).

It's worth noting that the C1/C2 error correction present on all types of CDs is pretty good, so it is entirely possible to make multi-generation copies with no errors whatsoever. The "cooked" approach for CD-ROMs just happens to be safer.


Subject: [3-19] How can I compress or encrypt data on a CD-ROM?

The easiest way is to use your favorite compression or encryption utility and process the files before putting them on the CD. However, this isn't transparent to the end user.

CRI-X3 enables programs like DoubleSpace to work on a CD. It's intended for a publisher or for significant internal use, and the licensing is priced accordingly. See http://www.cdrominc.com/. (Side note: the company filed patent infringement suits against Traxdata and CeQuadrat in Sep 1998 for distributing CD compression software. This might account for the dearth of similar applications.)

A straightforward solution is to write all of the files onto the disc as .ZIP files, and then use ZipMagic (formerly ZipFolders) to view the contents. It can be found at http://www.ontrack.com/zipmagic/.

PGP at http://www.nai.com/ (was http://www.pgp.com/) has some good encryption software, but none of it seems directly applicable to software distribution. PGPdisk, available for the Mac, might be useful but it isn't clear whether it can be used to distribute CD-ROMs.

ScramDisk, from http://www.scramdisk.clara.net/, writes files into encrypted "containers" on disk. It can be used with CD-ROMs, runs under Win95 and Win98, is free, and even includes source code.

http://www.c-dilla.com/ had information on CD-Secure 2, which allowed publishers to distribute network-licensed or "pay for the parts you need" products, and CD-Compress 2, which provides a way to compress data transparently on production CDs. The company is now part of Macrovision.

EnCrypt-CD encrypts the blocks as they are written to CD. It's a shareware product, available from http://www.shareit.com/programs/102046.htm.

Encrypted Magic Folders from http://www.pc-magic.com/ claims to transparently encrypt data as it's being used. Whether it would work from a CD-ROM isn't stated.

You can install a cryptographic filesystem (called "CFS") under Linux; see http://www.linuxdoc.org/HOWTO/Security-HOWTO-6.html#ss6.10. Create a crypto-fs, copy your data onto it, then use mkisofs with Rock Ridge extensions enabled to create an ISO-9660 disc image of the encrypted data. Burn the image to CD-ROM.

You may be able to use E4M, from http://www.e4m.net/.

BestCrypt, from http://www.jetico.com/, lets you create encrypted virtual volumes in a file that can be stored on CD-R media.

You can get PC Guardian's CD-ROM encryption from http://www.pcguardian.com/.

WinDefender, available from http://www.RTSecurity.com/products/windefender, provides transparent CD-ROM encryption from Windows.

Dynamic-CD can encrypt and password-protect CD-ROMs. See http://www.phdcc.com/dynamic-cd/.


Subject: [3-20] Can I do backups onto CD-R?

Yes. See section (6-7) for software.

Of course, it's not really necessary to use special software if you're just backing up your data files. Most CD creation programs will allow you to copy arbitrary files onto CD-ROM, and by using the Joliet standard or the UDF filesystem you can preserve long filenames. Unfortunately, if you're not using packet writing, the individual files may show up as read-only under DOS and Windows, so write permission must be re-enabled by hand when the files are restored. With packet writing applications like DirectCD or PacketCD, the correct file permissions are maintained.

(See section (3-57) for instructions on clearing the read-only flag.)

One thing to be careful of on Windows-based PCs: most programs that put files on CD don't preserve the *short* file names that are automatically generated for files with long file names. This presents a problem because the short form is often stored in the Registry and INI files instead of the long form (try searching your Registry for "~1"). When your system is restored, it may not be able to find the files anymore.

A way to work around this is to use a backup program that understands only the short filenames, and save the long ones with LFNBK. A program called DOSLFNBK at http://www8.pair.com/dmurdoch/programs/doslfnbk.htm may be more convenient than LFNBK.


Is CD-R better than, say, DDS-3 tapes? Maybe. Tape formats like DDS and DLT hold considerably more than a CD-R, but because the drives are streaming rather than random access, recovery of a specific file can be slower. For backing up a large system or network, tapes are more convenient. For making backups of a small system, especially one where access to older versions of files is frequently desired, CD-R is the better choice.

Some people prefer CD-RW. For daily incrementals, CD-RW makes sense. For weekly or monthly full backups, you probably want to retain the discs in case file corruption or deletion goes unnoticed for some time.

The longevity of magnetic tape is well understood (around 15 years for most formats). The longevity of CD-R is a little harder to quantify. See section (7-5) for details.


Subject: [3-21] How do I automatically launch something? Change the CD icon?

This can get surprisingly involved on a PC. The next few sub-sections go into detail. For a Mac, the answers are pretty simple:

You can use the Macintosh equivalent of Autorun (QuickTime 2.0 Autostart) to automatically launch an application or document on the Mac. The "-auto" flag of mkhybrid (6-1-32) lets you specify this.

Changing the icon on the Mac can be done by using Toast to record a disc image (record by "Volume" instead of "Files and Folders"). Change the icon on the disc image file from the Command-I window in the Finder, then record it.


Subject: [3-21-1] How does Windows "autorun" work?

The "autorun" feature of Windows 95 and later allows a program to be executed right after a CD-ROM is inserted. For this to work, the system must have autorun enabled, and Auto Insert Notification ("AIN") must be turned on for the CD-ROM drive. See section (4-1-1) for more information on AIN and the use of "TweakUI" to modify settings. It may also be necessary, in some configurations, to close the last session on the disc, or AIN will not work.

When preparing a CD-ROM for Windows, put a text file called "autorun.inf" in the root directory that contains something like this:

[autorun]
open=filename.exe
icon=someicon.ico
When inserted, the CD-ROM will be shown in the "My Computer" window with the specified icon. If the disc is inserted on a system with AIN and autorun enabled, the program named on the "open" line will be launched.

Icons must be in Windows icon or bitmap format. You can't use a GIF or JPEG. Make it square, 32x32 pixels. If you're going to be doing a lot of these, you may want to try Axialis "IconWorkshop", from http://www.axialis.com/axicons/.

There doesn't appear to be a way to specify custom icons for individual folders.

Incidentally, the "root" directory is the top level of the disc, e.g. "D:\". (If you viewed a directory hierarchy as a tree growing upward, the topmost directory would be at the root of the tree.)

Here's a more complicated example:

[autorun]
open = setup.exe /i
icon = setup.exe, 1
shell\configure = &Configure...
shell\configure\command = setup.exe /c
shell\install = &Install...
shell\install\command = setup.exe /i
shell\readme = &Read Me
shell\readme\command = notepad help\readme.txt
shell\help = &Help
shell\help\command = winhlp32 help\helpfile.hlp
Taking it line by line, this says:
  • The default AutoRun command will be "setup /i"
  • The icon for the CD will be icon #1 embedded in setup.exe
  • Four commands will be added to the right-click pop-up menu:
'Configure...',
which will run "setup /c"
'Install...',
which will run "setup /i" (same as auto-run in this case)
'Read Me',
which launches notepad.exe to display "help\readme.txt"
'Help',
which displays the file "help\helpfile.hlp" with the Win95 help facility
You can test the autorun features of a disc without recording one. If you SUBST a folder onto a drive letter, the autorun feature will scan the new drive. For example, from a DOS prompt, enter "SUBST J: \goodies\NewCD". This technique is also useful for testing out a CD-ROM you're preparing.

If you'd rather not have to deal with all this, try one of the applications listed in section (3-21-3).


Subject: [3-21-2] How do I launch a document (like a web page)?

In the past it was recommended to use the "start" command, e.g. "open=start index.htm". However, "start.exe" doesn't exist in the Windows NT family (NT4, 2000, XP).

You can launch documents with Windows Explorer on any version of Windows, like this:

[autorun]
open=explorer.exe index.htm
However, it appears to ignore your browser settings. So, even if you've chosen to make Netscape or Opera your web browser, it will still open the HTML file with Internet Explorer.

An alternative to "start", called "shellout", is available from the "files" section on http://www.mrichter.com/. This is a trivial launcher that you copy onto a disc and use like this:

[autorun]
open=shellout index.htm
It appears to avoid the above problems, is only 20K, and is free.

For more information on autorun:

http://www.microsoft.com/msj/defaulttop.asp?page=/msj/0499/win32/win320499top.htm
Instructions for making a VideoCD autoplay under Windows can be found at http://navasgrp.home.att.net/tech/autoplay_vcd.htm.


Subject: [3-21-3] What autorun software is available?

Some simple, configurable autorun applications (launchers and menus) are available, most as shareware:

http://cloanto.com/menubox/
http://www.indigorose.com/
http://www.pollensoftware.com/autorun/
http://www.phdcc.com/shellrun/
http://www.mediachance.com/
http://www.pgd.dk/
http://hyper-publish.com/
http://www.trah.co.uk/starterfile/
http://www.startertool.com/
http://go.to/traction/
http://www.timeless.co.zw/software.cfm

 

Subject: [3-22] How can I be sure the data was written correctly?

The easiest way is to compare the original with the copy. Some programs, such as recent versions of Nero, will automatically compare the disc contents with the original files. You can also use something like CD-R Verifier from http://www.cdrom-prod.com/cd-r_verifier.html or CDCchedk from http://Fusion.zejn.si/ to check the contents of an entire CD-ROM easily.

Another way is to do a recursive file-by-file comparison. Programs that compute CRCs on files and then compare them (often used for virus-checking) will work.

One way to do this is with use the UNIX "diff" utility, which is available for Windows (along with many other similar utilities) from http://www.reedkotler.com/. If you had copied the contents of C:\MyData onto a CD-R at E:\, you would use:

diff -q -r C:\MyData E:
The "-q" flag tells it to report if the files differ, but not show what the differences are, and the "-r" flag says to descend into directories recursively.

There are many other options. A utility called "treediff", available from the Simtel archives (http://www.simtel.com/), may be helpful. http://www.funduc.com/directory_toolkit.htm has a shareware program with some relevant features. http://www.araxis.com/ has an evaluation copy of PMdiff, available for Windows and native OS/2. You can get "FileSync" from http://www.fileware.co.uk/.

You can also use Microsoft's WinDiff, which -- unlike some of the programs mentioned earlier -- understands long filenames. It can be found on Microsoft's recent operating system discs, e.g. on Win98 it lives in \tools\reskit\file\windiff.exe. It used to be available for download from ftp.microsoft.com, but they rearrange that site frequently, so there's not much point in including a URL.

An alternative to windiff is xdiff, from http://www.wookie.demon.co.uk/xdiff/.

Rocksoft Pty has a product called Veracity (http://www.veracity.com/) that can check the integrity of a directory tree.

Visit http://www.fuw.edu.pl/~jt/cdvfy/ for some shell scripts that will compute MD5 checksums on a tree. Under Windows, try Advanced CheckSum Verifier from http://www.irnis.net/ for MD5 and CRC32, or md5summer from http://www.md5summer.org/.

If you *really* want to verify your discs, try http://www.audiodev.com/.


Subject: [3-23] How do I create, copy, or play Audio Karaoke/CD+G discs?

For playing Karaoke and CD+G:

For creating them:

For copying them (whole disc or individual tracks):

The following is an excerpt from the http://www.goldenhawk.com/ web site, regarding the drives CDRWIN supports for CD+G (Karaoke) copying.

"To backup CD+G discs, you must have one of the following recorders...

Hewlett Packard 7500 / 8100 / 8200 / 9100 / 9200
Panasonic CW-7501
Plasmon CDR4240
Plextor PX-R412C (must have firmware version 1.07)
Plextor PX-R820T / PX-W4220T / PX-W8220T)
Sony CRX100E / CRX110E / CRX120E / CRX140E / CRX140S
Yamaha All Models
All of the above recorders (except the Yamaha CDR100/CDR102, CW-7501, and CDR4240) are capable of both reading and writing CD+G discs. If you do not have a model that can read CD+G, then you will have to purchase a separate CDROM drive that has this capability.

The following CDROM drives are supported for reading CD+G discs...

Plextor 4Plex Plus
Plextor 8Plex (not recommended)
Plextor 12Plex
Plextor 12/20Plex
Plextor 14/32Plex
Sony 76S (not recommended)
Sony 415 (only works well at 1x reading speed)
"
There may be other units that work as readers or writers; see http://magicland.com/karaoke/drives.htm for a more comprehensive list. If you have a particular piece of software in mind, check the web pages for the software -- the publishers usually have a reasonably current list of supported drives on the site.


Subject: [3-24] How do I copy a CD-ROM with 3GB of data on it? A huge VideoCD?

You don't. The CD-ROM doesn't actually have that much data on it. Some CD publishers use a trick where they reference the same spot on the disc several times with overlapping files. If you try to do a file-by-file copy from the disc onto your hard drive, you'll end up with several copies of the same blocks, and more data than can fit on a CD-ROM.

VideoCDs often appear to have individual files that are 700MB or more. In this case, they really *are* that big. They're written in a special format that drops error correction in favor of more space. This works fine for video data, but is definitely not recommended for ordinary data.

If you want to duplicate a CD-ROM, you should use a program meant for the purpose (Roxio's CD Copier, Golden Hawk's CDRWIN, etc). Some software is more capable of dealing with complex CDs than others, so if you have a particular kind of CD in mind (such as VideoCD) you should check the capabilities of the software before making a purchase.


Subject: [3-25] How do I get my CD-R pressed into a real CD?

There are a large number of companies that will do modest production runs of pressed CDs, but listing them is beyond the scope of this FAQ.

Do a web search on "CD duplication" and "CD replication", or check out http://www.cd-webstore.com/BurningIssues.html (a licensed-access web site from the www.cd-info.com folks).

Sometimes a disc submitted for duplication will be rejected due to E32 (uncorrectable) errors. If you have a disc rejected, make sure you are using disc-at-once recording mode -- the gaps left between tracks by track-at-once mode are sometimes interpreted as errors. If the problems persist, try changing to a different kind of media, or even a different recorder.


Subject: [3-26] How do I make a CD without that two-second gap between tracks?

Most CD recorders are capable of doing this, given the right software. The key is to use disc-at-once recording instead of track-at-once.

Some programs give you a great deal of control. Golden Hawk's CDRWIN (6-1-7) will let you specify the gap size for each track, down to zero, and set the location of the track and index marks. You can put each track in a separate file or have the entire recording in a single file. Other programs, like ECDC (6-1-26), are easier to use but less flexible.

You will almost certainly need to use disc-at-once recording. Most drives insist on inserting a two-second gap between tracks when track-at-once recording is used, and those that don't will at best leave an instant of silence between tracks. You can eliminate the gaps from a TAO recording by putting the entire CD into one track, but then you lose the ability to seek immediately to the start of a song.

Most PC and Mac software support both TAO and DAO recording modes. It's prudent to check the web pages before you buy.

If you want to break up a long recording into several WAV files (one per track), it's important to split tracks on precise 2352-byte boundaries. If you don't, you'll get tiny periods of silence or noise, lasting less than 1/75th of a second, that may be clearly audible depending on the context. A handy Windows utility called "CD Wave" (section (6-2-16)) is good at splitting large WAV files into smaller ones, and can do so on block boundaries.

If you want to mix WAV tracks together, take a look at Multiquence, http://www.goldwave.com/multiquence/index.html. A simpler merge utility is "wavmerge", from http://www.mrichter.com/cdr/files/files.htm.


Subject: [3-27] How can I record RealAudio (.ra), MIDI, WMA, and MP3 on a CD?

Most CD players can only handle uncompressed audio in "Red Book" format. Some newer player, such as the AIWA CDC-MP3 and Philips Expanium, can play MP3 files from a CD-ROM. Such discs should be written in ISO-9660 with 8+3 filenames, and ought to use 128Kbps and "plain" stereo for broadest compatibility. The documentation for the I-Jam (http://www.ijamworld.com/) recommends putting no more than 50 MP3 files in a directory.

If you don't have such a player, though, you need to write a standard "Red Book" audio CD. The first step is to convert from whatever format the sound is in to WAV or AIFF. In some cases (e.g. MP3), many of the popular CD recording programs will do the conversion for you. If not, you will need to convert it to 44.1KHz 16-bit stereo PCM format. Once it's in WAV or (on the Mac) AIFF format, you can record it as you would audio taken from other CDs. Be sure to play it back once after you convert it to make sure that it came out okay.

For a tutorial on converting CD-DA to MP3 and vice-versa, see http://www.cdpage.com/Compact_Disc_Consulting/Tutorial/mp3.html. The "getting started" guide at http://help.mp3.com/help/ is worth reading, and the newsgroup FAQ for alt.binaries.sounds.mp3.* at http://www.mp3-faq.org/ is also useful. Making MP3s from CDs is discussed on http://mmsound.about.com/compute/mmsound/library/weekly/aa032700a.htm.

WMA is Windows Media Audio, part of Microsoft's attempt to create an architecture for "Digital Rights Management" protected media. A WMA player isn't supposed to let you hear any music you don't have the right to play. If you want to record it to CD, and the player won't let you do the conversion to WAV, you can still use a general-purpose sound recorder like Total Recorder to do the job.

There may or may not be a converter for the format you're interested in. Here are some links to try:

MIDI

MPEG audio (a/k/a MP2 and MP3) RealAudio General (sound driver that writes to disk -- works for anything you can play) You can't write MPEG, AC3, or other compressed audio formats to a CD-DA disc and expect to play it back in your car stereo. CD players only understand uncompressed PCM audio.

See http://www.howstuffworks.com/mp3.htm for an intro to MP3 technology. The site at http://privatewww.essex.ac.uk/~djmrob/mp3decoders/ has comparisons of various MP3 players.

http://www.sonicspot.com/multimediaconverters.html has a collection of converters for different formats.

If you *really* want to be able to play MP3-compressed songs while driving down the freeway, check out http://utter.chaos.org.uk/~altman/mp3mobile/ (or the commercial counterpart at http://www.empeg.com/).


Subject: [3-28] How do I add CD-Text information?

CD-Text is a standard that allows disc and track information to be embedded on an audio CD. The data can be read by some CD players, providing a way to have disc information available without having to enter it manually or look it up in a database.

Adding CD-Text to the discs you record requires a compatible recorder and capable software. Support was scarce in mid-1999, but is more common now.

The currently available software supports writing of album title, artist names, and track titles, and can copy discs with CD-Text data already on them. Storing lyrics within the tracks is possible but not widely supported.

Not all CD players and CD-ROM drives can read CD-Text. If this feature is important to you, check the specifications before you buy. Some programs, notably Windows Media Player, claim to read CD-Text but will actually use an Internet database instead.

Some MD recorders have a feature that lets you copy the CD-Text info from audio CDs (e.g. "Joint Text"), but it appears that some CDs prohibit the copying. The result is the message "Text Protected".

The site http://www.ncf.carleton.ca/~aa571/cdtext.htm has some additional details.


Subject: [3-29] Can I distribute a web site on a CD-ROM?

You need to include the content and a browser on the CD. Some products that might be helpful are:

PHD Computer Consultants - Dynamic CD
http://www.phdcc.com/dynamic-cd/
Softword Technology - Browse and View:
http://www.pc-shareware.com/browser.htm
Faico - NavRoad
http://www.offlinebrowser.com/ or http://www.faico.com/
Verity - CD-Web Publisher
http://www.verity.com/
See http://www.phdcc.com/helpindex/cdroms.html for some suggestions on putting web pages on CD-ROM.

See http://www.microsoftfrontpage.com/content/ARTICLES/fp_to_cdrom.html for an article about creating HTML CDs using FrontPage 2002.

If it doesn't need to be in HTML format, the full Adobe Acrobat writer can reportedly convert an entire web site into a PDF document.

Incidentally, if you burn the disc with plain ISO-9660, you don't have to worry about the upper-case filenames conflicting with lower-case names in URLs. The filesystem code on Windows, Mac, and UNIX converts the names to upper case before comparing them. This may not hold for other formats, e.g. Rock Ridge.


Subject: [3-30] How do I clean my CD recorder?

In general, you shouldn't. Generally speaking, the only reason you'd need to clean a recorder or (for that matter) a CD-ROM drive is if you went and stuck your finger on the lens. Cleaning kits and well-intentioned Q-tips are unnecessary and potentially dangerous. If you push too hard on the lens while cleaning and damage the mounting, it will no longer matter how clean it is.

Some people report drives coming back to life after a careful cleaning, so there may be some value in doing so. If your drive has become increasingly flaky over time, cleaning it may help.

[ Personal note: I've never had to clean a lens in *any* CD player, including a flip-up top-loading boom box that I've had since mid-1990. I can *see* the dust inside, and I can see the lens, but it has no problem playing discs. I can't imagine how a recorder that's only a year or two old is going to collect enough dust to fail, unless you play a lot of really crusty discs. ]

If you have an overwhelming desire to clear loose dust out of your recorder, and can't or don't want to send it to a service center, use gentle(!) bursts of compressed air (like that used to clean camera lenses). The idea is to knock any dust loose without knocking the lens free of its mounting. A more vigorous approach is to use a Q-tip and isopropyl alcohol, but this should only be used if the previous approach fails.

The Repair FAQ at http://www.repairfaq.org/ has a section about CD-ROM drives that seems relevant. Find the "Compact Disc Players and CDROM Drives" section, and skip down to part 4. One relevant quote, from section 4.3, regarding "cleaning discs":

"I generally don't consider CD lens cleaning discs to be of much value for preventive maintenance since they may just move the crud around. However, for pure non-greasy dust (no tobacco smoke and no cooking grease), they probably do not hurt and may do a good enough job to put off a proper cleaning for a while longer. However, since there are absolutely no sorts of standards for these things, it is possible for a really poorly designed cleaning disc to damage the lens. In addition, if it doesn't look like a CD to the optical pickup or disc-in sensor, the lens cleaning disc may not even spin. So, the drawer closes, the drawer opens, and NOTHING has been accomplished!"

 

Subject: [3-31] Is it better to record at slower speeds?

It depends on your recorder, media, and who you talk to. For example, some informal testing with the venerable Yamaha CDR-100 determined that it worked best at 4x speed with media certified for 4x writes. 1x worked almost as well, but 2x would occasionally produce discs with unrecoverable errors.

With audio CDs, the results are more subjective. Some people have asserted that you should always write at 1x, others have stated that 2x may actually be better. It depends on the recorder, media, player, and your ears. Try it both ways and listen. See section (4-18) for some notes on how you can write the same set of bits to two CDs and still have audible differences.

CD-R media is written by heating up tiny sections of the disc. When the disc spins faster, the laser has less time to shine on a particular spot, so the laser has to be controlled differently. Different formulations of media may require a different "write strategy" at certain speeds, and each recorder may adjust its write strategy differently to accommodate those speeds. This can potentially result in combinations of recorder and media that work perfectly at one speed but fail miserably at another.

Put simply, there's more to writing at high speed than just spinning faster. There is no One True Answer to this question. Do what works best for you.

See "The Speed of Sound: How Safe is High-Speed CD-Audio Recording?" at http://www.emedialive.com/EM2000/starrett5.html, for a very thorough analysis of audio disc quality at several different speeds. With some recorders and some media, it's actually better to write faster -- but in none of the tests performed did the error rate get anywhere near danger levels, regardless of speed.

See the graphs at http://www.digido.com/meadows.html for an examination of BLER (BLock Error Rate) with different recorders, different media, and different recording speeds. A few of the graphs show the same recorder and same media at different speeds, and in some cases the BLER increased at higher speeds, while in others it decreased.

There is some cause to believe that recording at higher speeds can result in increasing "jitter". This doesn't cause any difference in BLER or in the extracted audio, but is audible during playback. See section (2-41).

See http://www.cd-info.com/CDIC/History/Commentary/Parker/stcroix.html for commentary about "write strategy" selection and different media types.


Subject: [3-32] Where do I get drivers for my CD recorder?

In general, you don't need them. Software that burns CD-Rs has the necessary drivers built in.

If you want to use certain older recorders as CD-ROM drives, you may need drivers for them. See section (5-8).


Subject: [3-33] Can I copy discs without breaking the law?

This varies significantly from country to country. Information for USA and Canada follows. Most nations have some form of copyright protection that restricts duplication.


Subject: [3-33-1] ...in the United States of America?

You are allowed to make an archival backup of software, but the same doesn't necessarily hold true for music. The Home Rights Recording Act will allow you to duplicate music under certain circumstances.

A discussion of the topic, including details on past and pending legislation, can be found on the Home Recording Rights Coalition web site at http://www.hrrc.org/. The text of the Home Rights Recording Act can also be found here.

The Recording Industry Association of America, which represents the music industry, has a web site at http://www.riaa.com/.

An article entitled, "Copying Music to CD: The Right, the Wrong, and the Law" is at http://www.emediapro.net/EM1998/starrett2.html.

http://www.brouhaha.com/~eric/bad_laws/dat_tax.html has some relevant information and pointers.

http://www.bmi.com/ and http://www.ascap.com/ have yet more perspectives on legislation.


Subject: [3-33-2] ...in Canada?

Rules for copying software resemble those in the USA.

The rules for music are more lenient. Because of the media tax imposed by the Canadian government (see section (7-13)), you are allowed to copy any music for your own personal use. This means that you can go over to a friend's house and copy any number of discs you like, so long as they are for your own use. You are not allowed to make copies of music and then give them to others.

See http://www.cb-cda.gc.ca/decisions/toccopy-e.html, "Tariff of levies to be collected by CPCC in 1999 and 2000 for the sale of blank audio recording media in Canada".


Subject: [3-34] Can CD-Rs recorded at 2x be read faster than 2x?

Of course.

The only possible basis in fact for the, "if it was recorded at 2x, you can't read it faster than 2x" rumors is that some drives have trouble reading CD-R media. Discs that are hard to read when spinning at 12x may become easier to read when spinning at 4x. It has also been noted that some recorders will write more legible discs at certain speeds (e.g. the Yamaha CDR-100, which works better at 1x or 4x than it does at 2x). None of this should lead anyone to conclude, however, that the write speed and read speed are tied directly together. The reader, writer, and media all have a role in determining how quickly a CD-R can spin and be readable.

It's also the case that discs written at high speed (say 8x) can be read by drives *slower* than 8x. So if you're distributing discs to people with old 4x CD-ROM drives, you don't have to worry about them not being able to read at 8x. Of course, if the CD-ROM is poorly constructed, or the writer is producing marginal discs at high speeds, you might see evidence to the contrary, but there is no technical barrier to reading discs recorded at 8x or 12x on a slower drive.


Subject: [3-35] How do I make my CD-ROM work on the Mac, WinNT, and UNIX?

This is a tricky one because of issues with long filenames and file attributes. Mac CD-ROMs are typically burned with an HFS filesystem, not ISO-9660, and WinNT uses a different scheme for long filenames (Joliet) than UNIX does (Rock Ridge). Some variants of UNIX will recognize the Joliet names, but neither Windows nor the Mac understands Rock Ridge. You might be able to use an HFS CD-ROM on a platform other than the Mac, but if you're distributing software, it's not wise to assume that your customers will be able to do the same.

The easiest way to create a disc that will work on all platforms is to use plain level 1 ISO-9660, with 8+3 filenames and no special file attributes. If you need to include Mac applications as well as data -- or pretty much anything with a resource fork -- this simple approach won't work. Also, some older versions of Mac OS and HP/UX might not work as expected unless you record the disk without the usually-invisible version number (";1").

There is an Apple-defined extension to ISO-9660 that allows the Mac file and creator types to be present on an ISO-9660 filesystem. This allows most of the features of the Mac filesystem on an otherwise plain ISO-9660 disc. It's not clear how many of the software products in section (6-1) take advantage of this, but "mkhybrid" (section (6-1-32)) and MacImage ( section (6-2-10)) seem to. Section (3-5-3) has a URL to an Apple tech note with implementation details.

A common way to construct a disc for the Mac and PC is as a "hybrid" disc that has both an ISO-9660 filesystem and an HFS filesystem. To save space, the data itself is shared by both sections of the disc. This is possible because the ISO-9660 directory entries use an absolute block offset on the disc, so they can point at data residing in the HFS filesystem.

There are various applications that will do HFS/ISO-9660 hybrids. Roxio's Toast for the Mac and "mkhybrid" for the PC are two examples. Search for "hybrid" in the list of software in section (6-1) for more examples.

The issue of Joliet vs. Rock Ridge can also be solved, by including both kinds of extensions on the same disc. The "mkhybrid" program can include Joliet, Rock Ridge, and HFS all on the same disc. You can even have files appear on one kind but not the other, and rename files on the fly, allowing you to have a "readme.txt" with different contents for Mac, UNIX, and Windows.


Subject: [3-36] How do I put "hidden tracks" and negative indices on audio CDs?

With a little searching you can find an audio CD that will cause your CD player to show a negative track time when one track finishes and the next begins. The negative sections are usually filled with silence, but some rare discs will have material in them. If you seek directly to the track, you don't see (or hear) the negative-time section.

The trick here is also described in section (3-14). You can specify the start position of an audio track anywhere within the track. The start position is at time index 00:00 (in minutes and seconds, MM:SS), so the music before the start point is usually displayed with negative time values. When you seek directly to a track, the player jumps to time index 00:00, but when you play through from a previous track you hear the entire track.

When using CDRWIN-style cue sheets, the actual start of the track is at "index 00", and the place where the player seeks to is "index 01". The The distance between the indices is called the pre-gap. The Red Book standard requires that index 01 in track 01 be at least two seconds (150 sectors) from the start of the CD.

You can specify additional index markers, but most CD players will simply ignore them. Some CD-ROM games have tried to use the index markers as a form of copy protection, because they won't get copied automatically by many programs.


If you want to create your own discs with "hidden tracks", you need a program that gives you full control over where the index markers go (CDRWIN is one such program). Combine two (or more) tracks with an audio editor into a single file. Specify the file as a single track in the cue sheet, set "index 00" to time zero, and set "index 01" to a point right after the "hidden" song finishes. There are other ways to approach this, but this is probably the most straightforward.

It should be mentioned that the only truly "hidden" track is in track 1. Most CD players will play the entire disc, from index 01 on track 1, straight through to the end, so any tracks you try to "hide" in the middle of the disc are simply difficult to seek to. The only way to play audio tucked into the pre-gap in track 1 on most players is to hold down the rewind button.

For more information about unusual audio CDs, see "CD Oddities" at http://www.turbine.com/oddcd/.


Subject: [3-37] Do I need to worry about viruses?

Absolutely. Infected CD-ROMs are every bit as nasty as infected floppies, if not worse: you can't disinfect the source media. It is prudent to scan your files before creating a CD-ROM for distribution, and it's not a bad idea to scan the CD-ROM afterward (in case somebody has cleverly infected your CD writing software).

The dangers of boot sector viruses on bootable CD-ROMs are probably low. Because the boot sector is created directly by the recording software, and can't be modified after it has been written, the opportunity for infection is small.


Subject: [3-38] How do I cover up a bad audio track on a CD-R?

You don't. With a CD-ROM you could use multisession writes to hide unwanted data, but you can't create multisession audio CDs. (Well, you can create them, but nothing outside of a CD-ROM drive will be able to play the tracks outside the first session.)

On CD-RW media, it might be possible to overwrite an individual track. You would need software that supported this capability. Erasing the disc and starting over is probably easier.


Subject: [3-39] How do I duplicate this hard-to-copy game?

Requests for information on how to copy recent games occasionally sprout up on the newsgroups. Generally the publisher has employed some form of copy protection that prevents the disc from being duplicated easily. If you try to play the game from the duplicate, the game will usually act as if the CD-ROM weren't present and tell you to insert it.

Most publishers are well aware that there is no such thing as an unbreakable copy protection scheme. It is possible though to implement a method effective enough to slow the tide. If you don't believe that, start counting posts the next time a popular game with decent protection is released. See section (2-4) for some technical details, and section (3-42) for a discussion of why you can't write a general-purpose disc copier that works for everything.

If you're looking for information, the most appropriate places to search are "warez" newsgroups and web sites. Searching the net for tips is a good way to get started. Be forewarned that any "cracks" you download may very well also be viruses, and that if you give away or accept a copy of the disc from someone else you are probably breaking the law.

Aiding and abeting the illegal distribution of copyrighted works is not part of this document's charter. There are plenty of newsgroups and web sites devoted to the subject, so please don't waste bandwidth in "legitimate" forums asking for cracks. A search engine such as http://www.google.com/ will turn up many sites with such information.

Incidentally, the government of the USA and several other countries are starting to crack down on illegal trading of software and digital video. See http://www.usdoj.gov/opa/pr/2001/December/01_crm_643.htm for a press release on a December 11 2001 crackdown.


Subject: [3-40] Should I erase or format a disc? How?

First and foremost: you do not need to format a disc unless you're using a packet writing program like DirectCD. If you're running a program to create a CD, chances are good that you don't need to format it. If you're using "drive letter access", i.e. treating the CD-R or CD-RW like a big floppy disk, then you do need to format it.

Simple rule of thumb: don't format it. Most software that needs a formatted disc will format it for you as needed.

Formatting and erasing are different things. Formatting prepares a disc for recording. On a CD-R it writes a few basic things, on CD-RW it may write to most of the disc. The fixed-packet formatting that DirectCD does for CD-RW discs takes about 50 minutes on a 2x-speed rewritable drive.

Erasing, which can only be done to CD-RW media, restores the disc to a pristine state. If you want to erase a disc, use the software that came with your CD-ReWritable drive. Somewhere in the army of applications and mountain of menus is the command you're looking for.

The difference between "erase" and "quick erase" is that the former erases the entire disc, while the latter just stomps on the Table of Contents (TOC). It's like erasing the directory off of a floppy disk. The file data is still there, but since there's nothing pointing to it, the disc appears empty. (Some people have asked if it's possible to recover data from a quick-erased disc. Acodisc can do this; see section (4-35).)

The difference between "format" and "fast format" (such as is offered on the HP8100/Sony CRX100) is of a different nature. Both format the entire disc, and both operate at the same speed, but the "fast" format allows you to use the drive before formatting has completed. After a few minutes, you are allowed to access the drive while the formatting process continues in the background.

Incidentally, most conventional (pre-mastering) software will refuse to record on a disc that has been formatted for packet writing. In some cases the error message may be a confusing remark that insists the disc isn't writable.


Subject: [3-41] How do I equalize the volume for tracks from different sources?

A common problem when creating an audio CD compiled from many different sources is that the sound is at different volume levels. This can be slight or, after you've cranked up the volume to hear the first track, very much the opposite of slight.

There are actually two issues that determine how loud the music sounds. The first is the signal amplitude. Put simply, if you open a WAV file, this is how close to maximum the squiggly line gets. You can adjust the WAV file so that the highest amplitude is at maximum with the "normalize peak" function of a sound editor. Some programs, such as Roxio's Spin Doctor, may even do this for you automatically.

The second major issue is the dynamic range compression. This differs from data rate compression in that it doesn't make the WAV file smaller. Instead, it can make the quiet parts louder and the loud parts quieter.

A CD-DA has a dynamic range of about 96dB. If a symphony is recorded with a range of more than 110dB, it has to be compressed to fit on a CD-DA. In practice, you don't want whispers to be inaudible and shouts to be deafening, so the audio is often squeezed into an even narrower range. Radio stations often compress their broadcasts "up" so that music can be heard more clearly by listeners in cars or work environments.

(According to Ken Pohlmann's _Principles of Digital Audio_, 4th edition, page 35, ideal 16-bit quantization of a sinusoidal waveform is 6.02n+1.76 decibels, or 98.08dB. Using "dithering" techniques, it's possible to extend the effective resolution well beyond this, because of the way the ear perceives sound. There is an *excellent* introductory article at http://www.digido.com/ditheressay.html. Compression is more often employed on pop music recordings, where louder is better, than something like classical music, where accurate reproduction is desirable.)

To make a CD that sounds like it has equal volume across all tracks, you need to have the average sound level uniform across all tracks and have the peak volume be about the same on all tracks. One program that does essentially this is Audiograbber v1.40 and later, available as shareware from http://www.audiograbber.com-us.net/. (As of v1.41, you went into "Normalize Settings" and hit the "Advanced" button.) The tool is a little clumsy for serious audio mastering, but should do fine for preparing a "mix" CD that you'll be listening to in your car.

Another tool is "WAV file leveller", at http://www.plompy.co.uk/software.

Some programs approximate compression by letting you normalize against average RMS power. In this case, you are using a value that more closely matches the apparent loudness of the recording.

If you aren't dissuaded yet, http://www.digido.com/compression.html has an excellent article on compression, intended primarily for the budding recording artist but a good general reference nonetheless. Cool Edit 2000, available as shareware (section (6-2-14)), can do different kinds of compression, and is fun to play with.

Sidebar: "dB" is the abbreviation for "decibel", a signal strength ratio measured on a logarithmic scale. In a WAV editor like Cool Edit, which can show the sound level in dB, the loudness doubles every time you add 6dB. This is different from signal power levels, which double every 3dB (what you see in a WAV editor is analogous to voltage, not power). Detailed information is available from the Acoustics FAQ at http://www.Point-and-Click.com/Campanella_Acoustics/faq/faq.htm. See also http://www.ews64.com/mcdecibels.html and http://www.modrec.com/about/excerpt.php.


Subject: [3-42] How do I make a bit-for-bit copy of a disc?

A commonly posed question from the newsgroups: "what software can do bit-for-bit copies?" The expectation is software that can make an exact copy of the original.

There isn't any. If it helps to have a (convenient albeit somewhat inaccurate) mental image, picture a long string of bits arranged in a spiral. There are bits at the start of the spiral that you can't copy (the lead-in area), there are bits outside the spiral that you can usually copy if you request them ("raw" MODE-1 CD-ROM ECC and sector goop), and there are bits *under* the spiral that are blurry and hard to see (the subcode data).

What's more, there are copy protection features, such as *physically* damaged blocks, that a recorder isn't generally capable of writing. Other tricks, such as out-of-specification track lengths, can't be duplicated by most CD recorders because the firmware refuses to write them.

In no event can you guarantee an exact duplicate of the level 1 ECC (CIRC) encoding. In practice this doesn't matter, since no CD-ROM drive provides an interface for reading it directly.

Making a "bit-for-bit" copy of a disc would require reading the data at the lowest possible level, something that no production CD-ROM drive is capable of doing. Even if it were possible, there aren't any CD recorders that can write that sort of data.

Because of these limitations, you have to read a sector of data as a sector of data, not as a collection of frames scattered over half the circumference of the disc. The best you can do currently is "raw DAO-96" (section (3-51)), which reads the subcode data along with the the sector data.

Bear in mind that CD-ROM drives and CD recorders were designed for people who want to read and write data, not decipher arcane standards documents and perform their own error correction. Creating exact one-off copies was not a major consideration of the original design.

In general, however, you don't *need* a "bit-perfect" duplicate of the original. If what you're copying is a simple MODE-1 CD-ROM, you can make an "identical" copy by reading the sectors off the original and writing them to a duplicate. For most situations this is good enough: you have copied the bits that matter.

On the other hand, if it's a copy-protected CD-ROM with index markers in strange places, you have to use software and hardware that can see the "blurry bits" reliably and copy them.

See also sections (2-43), (3-1-1), (3-18), (3-39), and (6-1-49).


Subject: [3-43] How do I put punctuation or lower case in CD-ROM volume labels?

The name of a CD-ROM is determined by the CD-ROM volume label. This determines how the disc shows up on the Mac or Windows.

The ISO-9660 standard limits the characters in the volume name to the same set of characters allowed in a filename, namely A-Z, 0-9, '.', and '_'. Some programs enforce strict adherence to the standard, while others are more relaxed.

For example, if you wanted to create a disc with Nero that had a hyphen in the volume name, you would go into the "file options" and change the Character Set to "ASCII". Nero will then allow a broader range of characters. Other programs may or may not have similar features.

Remember that standards are guidelines, not laws enforced by threat of punishment. You are welcome to create discs that deviate from the standard in any way you choose. The only price you will pay is that, if you stray too far from the standard, your disc may not be readable by everyone. For the specific case of a volume label, deviations are pretty harmless.


Subject: [3-44] How do I extract audio tracks from an "enhanced" CD on the Mac?

Applications like "Toast" insist on showing the data track only. You can play the audio tracks, but you can't seem to extract them.

SoundJam MP from http://www.soundjam.com/ is reported to do the trick. The CD-ROM toolkit from FWB (http://www.fwb.com/) might also be of use.


Subject: [3-45] How do I disable DirectCD for Windows?

There are two basic approaches: (1) run the uninstall program, or (2) make changes to several entries in the Windows registry.

You CANNOT disable it by killing a task.
You CANNOT disable it by un-checking it in msconfig.
You CANNOT disable it by removing it from the system StartUp list.
All these really do is stop the DirectCD control interface from running. The icon is gone from the system tray, but DirectCD itself is still active, which you can verify by inserting an unfinalized packet-written disc. If DirectCD were actually disabled, the disc would be unreadable.

Writing data to such a disc without the user interface component active can lead to data corruption, because some of the safeguards are no longer in place. It's like you've taken the steering wheel off the car while it's still rolling.

If you do choose to use one of the "easy" methods, you will probably be okay so long as you don't try to write to a disc with packet writing.

DirectCD puts some drivers in C:\Windows\System\Iosubsys\. The set appears to be CDUDFRW.VXD, CDUDF.VXD, CDRPWD.VXD, and CDR4VSD.VXD. If you are having trouble un-installing DirectCD, check for the presence of these files, and rename the extension to ".VX_" if found.


NOTE: the DirectCD icon in the system tray is different from and independent of the "Create CD" icon that Easy CD Creator 4 adds to the system tray. You can get rid of that by right-clicking on it and telling it not to load.


Subject: [3-46] How do I specify the order of files (e.g. sorting) on ISO-9660?

You don't. The ISO-9660 specification requires that the files appear sorted.

Most modern OSs sort directories anyway, so unless you're greatly concerned about the appearance under DOS, there's little value here anyway.


Subject: [3-47] How do I put a password on a CD-ROM?

Encrypt the data on it. See section (3-19) for options.


Subject: [3-48] Can I record an audio CD a few tracks at a time?

That depends on what you're trying to accomplish. There are two issues that complicate matters:

  1. Most audio CD players only play tracks from the first session on the disc. (Most CD-ROM drives will play all sessions.)
  2. Most audio CD players only play tracks from a closed session. (In general, only a CD recorder can play from an open session.)
Suppose you record three tracks onto an audio CD, using track-at-once recording. If you don't close the session, you can add more tracks, but you can't play the disc. If you close the session, you can play the disc, but you can't add more tracks.

Some people have CD players that will play songs from every session. If you do, and compatibility with other players isn't important, you can write each group of tracks into its own session. The down side of this approach is that there is an appreciable amount of overhead when opening a new session (23MB for the first and 14MB for each additional one).

If your hard drive has enough space, you can just keep the WAV files on the drive, and burn the disc all at once. If it doesn't, you can write the tracks to a CD-R or CD-RW disc as WAV files on CD-ROM, and record from there. Write a new CD-R or CD-RW every time you get more tracks. (The advantage to using CD-ROM is that additional error correction is used.)


Subject: [3-49] How do I copy DVDs onto CD-R?

It isn't possible to take the contents of a DVD-Video or DVD-ROM and record the whole thing onto a CD-R, unless the DVD is nearly empty. The capacity of DVD discs is considerably greater. Generally speaking, you can't play DVD content from a CD-R disc anyway, because the DVD drive needs to read encryption keys from outside the filesystem area.

You could, of course, capture the video from a DVD-Video disc with a video capture board, re-encode it with MPEG-1, and write that as a VideoCD. The quality would be VHS-grade though. (You can get better results with MP3 audio and MPEG-4 video, but the process is a little convoluted. See http://www.digital-digest.com/dvd/support/dvd2mpeg4.html.) The next section talks about some ads you might have seen for products that do this.

You may have heard of DivX (sometimes "DivX ;-)"). Originally the name for a limited-playback DVD system, it now usually refers to MPEG-4 encoding of DVD video. See http://www.divx-digest.com/help.html for more details.

If you're only interested in the audio portion of a DVD-Video, you can extract the AC3 audio directly from the .VOB file, using some freely available utilities (notably "ac3dec" and the elusive "DeCSS"). You will need to convert the audio from 48KHz to 44.1KHz. You can also capture it under Windows with Total Recorder (6-2-19).

The story is the same with DVD-ROM: you can probably copy it to a CD-R if it will fit. If the contents only took up about 650MB, though, it probably wouldn't have been shipped on a DVD-ROM.


Subject: [3-49-1] I heard about software that copies DVDs with a CD recorder!

I'm guessing you've also heard of ways to get rich by sending money to other people, legal ways to get your bad credit history erased, and drug-free side-effect-free low-cost super cures made from all natural ingredients on distant tropical islands.

They're all nonsense. I can't help you if you believe in the above, but I can speak to copying DVDs with a CD recorder. Here's a piece from a message that was spammed at me (spelling and grammar errors left uncorrected):

COPY ANY DVD MOVIE
With our revolutionary software you can copy virtually any DVD Movie
using your existing equiptment! Conventional DVD copying
equiptment can cost thousands of $$$
Our revolutionary software cost less than the price of 2 DVD Movies!
If you go to the web site, it goes on to say:

Learn How To Burn DVD's onto Regular CD-R Discs and watch your new
movies on Any DVD Player, not just the computer DVD.
[...]
No DVD Drive Required!!!
Another, possibly unrelated, site says:

With detailed, easy to follow, step-by-step instructions, you can
BURN your own DVD Video using nothing more than our software and
your CD-R.
[...]
o No DVD Burner Required
o Superior Reproduction Quality
It has a link for their "frequently asked questions" document, but you have to give them your e-mail address to get it. Any company that refuses to give you information until you submit to their spam list is best avoided.

Let's start with the facts:

  1. You can't read a DVD in a CD-ROM drive. DVD requires a laser at a different wavelength; the disc has a different physical format; the disc has a different logical format. A firmware update is not going to make this work, so don't expect that installing new software is going to help.
  2. You can't put a full DVD on a CD-R disc. DVD movies are typically around 8GB, which is roughly 11x as much as you can put on a CD-R.
  3. Many DVD players can't read CD-R discs. This is because of the different laser wavelength. DVD player manufacturers have found several ways around this, but many players just can't handle CD-R.
  4. You can't easily duplicate the blocks with the security keys. They live outside the filesystem area. The only way to get the MPEG video off in a playable format is to strip the CSS encryption, and software that can do that is illegal to write, sell, or use in the USA (DMCA law).
Products like "DVD Wizard" and "DVD-Copy 2.1" cannot possibly do all that they claim. The best they can do is transcode the video into a lesser format. This requires ripping the MPEG-2 video off the DVD using a DVD-ROM drive, stripping the encryption, re-encoding the video in MPEG-1, and writing it to CD-R as a VideoCD. You will be going from 720x480 video recorded at up to 10.08Mbits/sec down to 352x200 video recorded at 1.5Mbits/sec. Instead of Dolby 5.1 you will have low-bit-rate stereo. On an 80 minute disc, you can store about 80 minutes of MPEG-1 video, so nearly all movies will require two or more discs.

This software will let you create a movie that could be played back in computers or *some* DVD players -- not all DVD players support CD-R media, and not all will play VideoCD -- but at roughly VHS quality, and without any of the features that make DVDs special. Most notably, you will lose all of the menus, audio options, and special features. You will not be burning "DVD Video", and in some parts of the world (most notably the USA) you will be breaking the law even if the copy is for personal use.

Software that does this sort of thing can be found, for free, on various sites on the Internet. (Because of the legal issues, it isn't always available in one place for long.) If you really want low-quality MPEG editions, save your money and search the web for DVD copiers or converters, and download the software for free instead of giving money to spammers. (The previous section has a couple of links that might be useful.)


Subject: [3-50] How do I copy Mac, UNIX, or "hybrid" CD-ROMs from Windows?

A program that copies the entire disc as an image should work. Don't try to copy it as a collection of files.

You can create a hybrid HFS (Mac), Rock Ridge (UNIX), and Joliet (Windows) CD-ROM with "mkhybrid" in section (6-1-32). The output of the program is a simple ISO-9660 image file. It stands to reason that you should be able to copy such discs as easily as you can create them.

The same applies to copying arbitrary discs from the Mac, or any other platform -- just copy it as a disc, and you should be fine.

If you're trying to copy a game, and it doesn't work, see (3-39).


Subject: [3-51] How do I copy something in "RAW" mode? What's DAO-96?

A sector on an audio CD holds 2352 bytes, enough for 1/75 of a second of stereo sound. A sector on a MODE-1 CD-ROM holds 2048 bytes of data. The 304 "lost" bytes are used for sector addressing, synchronization, and error correction.

If you read a MODE-1 CD-ROM sector in "cooked" mode, you get 2048 bytes of data. When you write that to a CD-R or CD-RW, the error correction bytes are reconstructed. If you read that sector in "raw" mode, you get all 2352 bytes of data. If you simply wrote those bytes to a CD-R, any errors that slipped past the CIRC encoding while reading would be propagated, and could result in generation loss (see sections (2-17) and (3-18)).

There are times when you don't *want* to have the error correction reconstructed. For example, some games deliberately distort the error correction bytes as a form of copy protection. See section (2-4).

The recording software has the option of error-correcting the 2048 bytes of CD-ROM data and even regenerating the ECC data. Doing either reduces the risk of generation loss; doing both eliminates the risk by effectively doing a "cooked" read and write. (Apparently some drives will error-correct CD-ROM data for you even in "raw" mode.)

To copy a disc in "raw" mode, you need the right reader, the right writer, and the right software. Programs like CloneCD specialize in "raw" copies, but require that the CD-ROM drive used to read discs and the recorder used to write them support "raw" reads and writes. The web page for CloneCD (6-1-49) is a good place to look for a list of capable hardware.

"RAW DAO-96" refers to a method for writing "raw" 2352 byte sectors with 96 bytes of associated P-W subcode channel data (section (2-6)). This is useful for copying discs with CD+G, CD-Text, and certain forms of copy protection. "DAO" refers to its use in combination with disc-at-once recording.

There's also "RAW DAO-94", which is the same as DAO-96 except that the two bytes of Q channel CRC data are always generated by the recorder, and "RAW DAO-16", which includes only the P-Q subcode channels.


Subject: [3-52] How do I do cross-fades between audio tracks?

A "cross-fade" is a smooth transition from one track into another. If done properly, with compatible music, the tracks appear to blend into one another.

Some of the fancier recording applications, such as Sound Forge (http://www.sonicfoundry.com/) and Waveburner (6-1-55), will do cross-fades. An "Advanced CrossFading" plug-in for Winamp can do them; set the output device to a file on disc (with a "disk writer plug-in"?), and play the music you want to record.

It's important to use disc-at-once recording when writing the tracks to avoid having two-second gaps inserted. See section (3-26).


Subject: [3-53] How do I create a CD with my favorite songs on it?

If you want to create a CD that includes songs from several other CDs, there are two basic approaches:

  1. Use a program, like Easy CD Creator Deluxe (6-1-26), that allows you to select tracks from multiple CDs on the layout screen. The "wizard" can walk you through the process.
  2. Extract the tracks you want to your hard drive, perhaps with a program like Exact Audio Copy (6-2-12), and then write them all at once.
The former is a little easier, and requires less disk space. The latter allows you to use disc-at-once recording, which prevents the recorder from inserting a two-second gap between each track.


Subject: [3-54] How do I record directly onto CD from a microphone?
(2001/03/02)

If you have a stand-alone audio CD recorder, this should be straightforward. Either you have a microphone input or you don't.

On a computer, you probably don't want to do this. The greatest advantage of using a computer-attached recorder is that you can edit the result before recording it. CD-R is write-once media, so if you make a mistake, you can't fix it later.

If you're determined to do this, Roxio's Spin Doctor (part of Easy CD Creator) can do what you want. Connect the microphone to the input on the PC sound card, start up the software, and record when ready.

The situation on non-PC platforms is similar: you can do it if your software supports it.


Subject: [3-55] Is it okay to record a CD from MP3?

Yes, though the quality won't be as good as if you had recorded directly from the original CD.

MP3 is a "lossy" compression format, meaning that it gets its exceptional compression ratios by throwing some of the data away. (MP3 can get a 10:1 reduction with hardly any degradation in audible quality; "lossless" compression is hard-pressed to do better than 2:1 on 16-bit samples.) The clever part about MP3 is the way it figures out what parts of the audio to throw away and what to keep, based on a model of human hearing.

Because it's a lossy format, every time you compress something you lose some of the quality forever. The smaller you compress it, the more you lose. The loss is more easily audible on some music than others, and if your equipment (or your ears) aren't very good you may not notice it at all.

If you like to copy CDs by ripping them into MP3 format and then recording them to MP3, be aware that your copies aren't quite as good as your originals. At 160Kbps it's going to be hard to notice, but at 64Kbps it should be easy to tell the difference between the original and the copy.

(Side note: if you want to do a double-blind test, play the original and the duplicate in random order for somebody else, and ask them if they can identify the original music. The test isn't to tell that the discs sound *different*, but rather to figure out which disc sounds *better*.)

For more information about lossy and lossless audio compression, see:

For some tutorials on converting between MP3 and other formats, see section (3-27).


Subject: [3-56] How can I test a disc image before recording?

You have a few options.

You can do a trivial check of an ISO disc image with WinImage. See section (6-2-2).

Under Linux, you can mount it via the "loopback" filesystem, e.g.: "mount ./cdimg.iso /mnt/test -t iso9660 -o loop".

Under DOS/Windows, you can "SUBST" a directory to make it look like a drive, e.g. "SUBST J: \goodies\NewCD" will make the contents of "\goodies\NewCD" appear to be mounted on the J: drive. This is a useful way to test autorun.inf files.

A more robust approach under Windows is to use a CD emulator. These programs usually use their own proprietary disc formats, but some converters are available (e.g. http://www.bluebitter.de/), and some can mount ISO images directly. Examples include Microtest Virtual CD (http://www.virtualcd-online.com/), Paragon CD Emulator (http://www.cdrom-emulator.com/), and Daemon Tools (http://www.daemon-tools.com/).


Subject: [3-57] How do I clear the "read-only" flag under Windows?

If you write files to a CD-R with conventional recording and then try to copy them back, under Windows the files will all have their "read only" flags set. This can be annoying for documents you want to update.

The files aren't written to the disc as "read only". There isn't any such permission flag in the filesystem. They're simply presented that way by Microsoft operating systems. Mac OS deals with this in a nicer way, showing unlocked files on write-protected media, rather than the dopey Microsoft approach of showing write-protected files on unlocked media.

You can avoid this situation entirely by using packet writing (where you just copy files to the disc like a big floppy, e.g. with DirectCD), which preserves the file attributes, or by using backup software, which will restore the files to their original state. Stuffing the files into a ZIP archive works too, but may be less convenient than other approaches.

If you've already got the read-only files, changing them back to read-write isn't too hard. Some approaches:

From a DOS prompt, run "ATTRIB -R *.* /S" on every subdirectory with read-only files in it.

If you prefer a Windows application, try "ReadOnly" from http://www.sente.co.uk/downloads.htm. They also have a more sophisticated application called "FlagRASH".

If you can boot into Linux, su to root, mount the volume as vfat, cd to the directory in question, and do "find . -print | xargs chmod +w" to enable write permission for all files in the current directory and in all subdirectories. If you've got the GNU utilities, use "find . -print0 | xargs -0 chmod +w" instead, because it'll work correctly on files with spaces in the names. (Of course, if you're a Linux user, you could just use mkisofs with the appropriate options and have Rock Ridge file permissions that match the originals, but this is a Windows question.)


Subject: [3-58] How do I share a CD recorder across a network?

There is no general way to access a CD recorder on a remote machine. You need to have software running on the machine with the recorder. This might be something as simple as DirectCD, to provide a filesystem that Windows can write files directly to, or something fancy that accepts disc images and queues them for recording.

Ahead's NeroNET (http://www.nero.com/) provides a client/server model for sharing CD recorders. See also CD Studio+ (section (6-1-6)).