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Apple Lossless Encoding can be used for audio from other sources, too.
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Al Fasoldt's reviews and commentaries, continuously available online since 1983
T h e R o a d L e s s T r a v e l e d
Apple's lossless compression makes iTunes an audiophile's delight
June 2, 2004
By Al Fasoldt
Copyright © 2004, Al Fasoldt
Copyright © 2004, The Post-Standard
I'd been disappointed for months with the sound quality of the music I've added to my iTunes collection from most of my audiophile CDs. The compressed audio wasn't as good as the original CD sound.
But my enthusiasm got a boost this spring when Apple introduced a new version of iTunes for both Mac OS X computers and Windows PCs. Almost hidden away in the improvements in the current version is a new, lossless method of compressing audio for your iTunes collection.
If you use the new method, called Apple Lossless Encoding, you can reduce the size of CD audio tracks by about 60 to 70 percent percent without any corresponding loss in sound quality. That's simply amazing.
Compressed lossless encoding isn't new. But doing it while the music is playing (so-called "real-time" compression and expansion) has been very difficult. The encode-decode (or "codec") system needed for such a sophisticated method requires a lot of computer power, too.
The only other lossless audio compression method, available for Windows, Mac OS, Mac OS X and Linux, is FLAC, which stands for "free lossless audio codec." FLAC is sometimes used by bands that want to release their music on the Internet but don't want to compromise on audio quality.
Apple avoided using FLAC in part because its own method would be able to maintain control over music copying if it were used for iTunes Music Store audiophile releases. (I'm just guessing, but I expect Apple to add lossless audiophile albums to the iTunes Store before long.)
I tested Apple Lossless Encoding using some of my favorite audiophile CDs, including a few from Reference Recordings, maker of some of the highest-quality CDs I've ever heard. I heard absolutely no difference in the sound of the CD vs. the sound of the iTunes compressed version using Apple Lossless Encoding.
When I made compressed (but not lossless) versions using MP3 and AAC encoding, the sound was sometimes very close to the audio quality of the original CDs, but this happened only when I raised the bitrate level (a measure of quality) to at least twice the 128 kilobits-per-second rate normally thought of as sufficient for high fidelity.
Apple Lossless Encoding can be used for audio from other sources, too. I transferred some of my early live digital recordings, made in the early 1980s, to my Macintosh using lossless encoding in iTunes. Unlike most CDs, my live digital recordings are unrelenting in their variations in loudness and quietness (I used no limiters), and the lossless encoding handled the wide dynamic range very well.
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