- How Digital Sampling Works
- Lossy Compressed Formats
- Lossless Compressed Formats
- Non-Compressed Formats
Lossless Compressed Formats
If you care about audio fidelity, lossy compression just doesn't cut it. No matter high the sampling rate or how good the compression algorithm, lossy files don't sound quite as good as the originals. (Remember that word "lossy"—you lose something in the translation!)
If you want to create a high fidelity digital archive, a better solution is to use a lossless compression format. These formats work more or less like ZIP compression; redundant bits are taken out to create the compressed file, which is then uncompressed for playback. So what you hear has exact fidelity to the original, while still being stored in a smaller-sized file.
Of course, a lossless compressed file isn't as near small as a file with lossy compression. While an MP3 file might be 10% the size of the original, uncompressed file, a file with lossless compression is typically about 50% the original's size. This is why lossless compression isn't recommended for portable music players, where storage space is limited. If you're storing your CD collection on hard disk, however, it works just fine—especially with today's cheap hard disk prices. You can easily store 1,000 CDs on a 300GB hard disk, using any lossless compression format.
What formats can you choose from? The list isn't quite as long as with lossy compression, nor or the formats quite as well known. Here's a short list:
- Apple Lossless Audio Codec (ALAC, M4A)—A lossless compression option available for use with Apple's iTunes and iPod.
- Free Lossless Codec (FLAC)—An open-source lossless format, embraced by many consumer electronics manufacturers and usable with all major operating systems, including both Windows and Linux.
- Monkey's Audio (APE)—A free lossless format, not widely used.
- Windows Media Audio Lossless (WMA), Microsoft's lossless compression format, available in Windows Media Player versions 9 and 10—probably the best option for lossless compression today. (Uses the same WMA file extension as normal Windows Media Audio files.)
- WavPack (WV, WVC)—An open-source lossless format, similar to FLAC, not yet widely used.