A compression balancing act
FLAC stands for Free Lossless Audio Codec, a format that strikes a harmonic balance between low quality lossy compression and its overweight lossless brethren. The trick to FLAC is that it does not remove any vital information from the audio stream itself, which is a surprising accomplishment considering that it is considered an appropriate way of playing back the average file while also providing excellent archiving duties.
As a result of its healthy balance between the two format spheres, FLAC is well supported by a number of software and hardware developers. The Xiph.org foundation, which is responsible for many of the advancements in Ogg Vorbis, announced its support of FLAC in January of 2003. Since this announcement the lossless format has grown exponentially.
In case you're wondering, the "free" in FLAC does indeed mean that the audio format makes a concerted effort to avoid copy prevention features. Although Xiph.org reserves the right to set some specifications for FLAC and ensure compliance, the basic creation of the audio format was based on the principal of giving freedom to amateurs by avoiding any accompanying patent for the software.
Perhaps the lossless compression device most comparable to FLAC is the old stand-by, ZIP. However, such a match-up is quite unfair, with ZIP achieving 10-20% compression and FLAC bounding forward with an impressive 30-50% compression rate.
While FLAC's compression rates do sound impressive compared with other popular lossless formats, it still trails the lossy competition by a wide margin. If the compression procedure were a cycling marathon, lossy compression formats like MP3 would be snapping the ribbon at the finish line while FLAC collapsed on an uphill climb miles behind. By comparison, most lossy compression-based codecs can reduce the size of their files by up to 80%.
However, those quick little devils might just have that grin wiped from their face. Like most international cycling events, the first few finishers are found to have taken more steroids than a horse. The internal problem with lossy compression, as we've seen, is that the procedure cheats the music file it is reducing in size. In many cases the original product loses a little bit of its overall quality through the compression and decompression process, making lossless technology like FLAC an attractive tool.