7.3. Choosing Music File Formats
When it comes to storing their pictures, digital photographers have it easy. They snap a picture, toss the resulting JPG files (Section 6.4) onto their hard drive, and open the photo in any program. Sound files, by contrast, come stored in a dizzying array of formats: MP3, WMA, AAC, and on and on and on.
Part of the problem comes from a music file's bulk. With music files in raw form, a CD can hold only a dozen or so songs. And each of the different music file formats shrink these files down using a variety of different strategies. (You'll occasionally see the terms lossy , which refers to compressed audio, and lossless , which means the file hasn't been shrunk at all and contains the same fidelity as the file on the CD.)
Another problem comes from copy protection. When you snap a photo, you're creating a picture you want to share with your friends , so camera manufacturers make that task easy. Record companies, by contrast, want to stop you from sharing songs. So some formats feature built-in virtual locks that limit the number of times you can copy a file, or even restrict which devices you can play it on.
Normally, dealing with several different audio formats wouldn't be a big problem. Windows XP, for instance, can open a wide variety of files. But most portable digital music players like the iPod can open only two or three different formats. Here are the ones you encounter most frequently.
Tip: Dubbed the "Swiss army knife of audio," you can use the free dBpower MC (www.dbpoweramp.com) program to convert sound files from one format to another as well as to rip CDs. dBpower MC supports MP3, WMA, AAC, WAV, and many other music formats.
7.3.1. WAV (WAVeform audio file)
You may not have heard of this format, but you've certainly heard the music. Musicians record their songs as immense WAV files, which do a yeoman's work by preserving the full quality of the original music. The music then moves straight to CD without any compression, letting songs retain their full quality.
When displaying a CD's contents in My Computer and similar programs, Windows XP does something confusing. Instead of showing the CD's WAV files and pleasantly offering to convert them into the more versatile MP3 files, Windows simply lists the uncompressed songs as shortcuts called CDA files: Track01.cda, Track02.cda, Track03.cda, and so on.
Note: Macintosh computers refer to WAV files as AIFF (Audio Interchange File Format).
Unless you're a musician recording with a home studio, you probably won't be messing with WAV files. They're much too big for most portable players, anyway. To pack as much music on a portable player as possible, people turn to the compressed file formats, discussed next .
Note: Microsoft stores Windows XP's logon and log off music as WAV files. These files are located in the Media folder of your C drive's Windows folder.
7.3.2. MP3 (Moving Picture Experts Group Audio Stream, Layer III)
Thankfully shortened to the acronym MP3, this sound format began life in the early 90s, survived the wrath of the recording industry and lives on as the world's most popular music format. MP3 squishes a song's size by nearly 90 percent (compared to the original WAV file), letting you cram hundreds of songs onto your PC, iPod, or other portable music player. Best of all, MP3 files work on nearly every portable music player sold.
Windows Media Player plays MP3 files without a problem. But creating MP3 files in Media Player 9, the version included with Windows XP, costs money. Patent-holder Fraunhofer (www.iis.fraunhofer.de/amm/) charges licensing fees of around $10 per computer for its MP3 codec a small file holding the formula for stuffing music into an MP3 file. That leaves you two options for creating MP3 files:
Some people simply bypass Windows Media Player altogether: The LAME (Lame Ain't an MP3 Encoder) MP3 codec works with several competing programs to create MP3-compatible files for free. Download and install the LAME MP3 codec (http://lame. sourceforge .net/), along with any of the recommended free MP3 encoding programs listed on the site.
7.3.3. WMA (Windows Media Audio)
Instead of supporting MP3, Microsoft offers its competing WMA format for storing files. Windows Media Player plays and creates WMA files. Many newer music players (but not the iPod) also support WMA as well as MP3.
Finding a WMA-compatible player has grown so complicated that Microsoft created PlaysForSure (www.playsforsure.com), a sales and marketing site disguised as a service for matching compatible players with download services and music formats. (A search for iPod on the site brings up only a competing player that handles WMA files; iTunes isn't even mentioned.)
Windows Media Player adds copy protection to every WMA file you create, stopping you (or anyone ) from playing back that file on another computereven on other computers you own. To disable the copy protection in Media Player, choose Tools Options and turn off the "Copy protect music checkbox.
7.3.4. AAC (Advanced Audio Coding)
AAC became Apple's soldier in the music format wars when Apple chose it as the format for the iPod, Apple's wildly successful digital music player. Although a large group of companiesincluding Dolby, Fraunhofer (FhG), AT&T, Sony, and Nokiacreated AAC, few competing music players play it, making it impractical for all but the legions of iPod faithful (more than 10 million at last count).
The iPod also plays MP3 files; to help sway PC customers with huge libraries of WMA files, iTunes for Windows converts non- copy-protected WMA files to AAC.
Apple's iTunes software sells only songs in the AAC format, and it adds copy protection to keep the file from moving to more than five PCs.
7.3.5. MID (Musical Instrument Digital Interface)
Converting a music file from one format to anothera chore you encounter when moving music to a digital music playerusually takes a few clicks on a converter program like dBpower MC (www.dbpoweramp.com). Converting MIDI files isn't nearly as easy, as the files don't contain recorded music, but instructions for how a synthesizer should play back a piece of music. Depending on the synthesizer, a MIDI file can sound as cheesy as a children's toy or as beautiful as a harp in the park.
If you need to convert a MIDI file to MP3 for a ring tone, for instance, fire up Apple's free iTunes program (www.apple.com). It converts MIDI to MP3 by playing it through your PC's synthesizer, and then records the results as it plays. Consequently, the resulting MP3 file sounds only as good as the sound card on the computer you use to convert it.
As for converting MP3 files to MIDI, forget it. Some programs offer a conversion feature, but the resulting file sounds pretty awful .