| Alternatives
to Digital Audio by: Hans Dekker
Although MP3 is the most popular format for encoding
music, it is by no means the only one. There are two
basic methods for compressing audio lossless and
lossy, and for each of these methods there are many
formats.
Lossless compression means that none of the audio data is
removed during compression. Lossy compression means that
audio data is permanently removed from the audio file.
Lossy compression results in smaller files, but there is
no way to rebuild the audio data to its original format.
MP3 is an example of lossy compression.
Lossy Compression Formats
There are many alternatives to MP3 when it comes to
encoding audio files. Microsoft reportedly developed the
WMA format to avoid the licensing costs associated with
MP3. WMA files can be played with the Windows Media
Player that is included with the Windows operating system
as well as many other audio players. It features similar
encoding rates to MP3 and similar file sizes.
AAC (Advanced Audio Coding) is the format preferred by
Apple and is used for its popular iTunes and iPod
products. AAC files can be smaller than MP3 files because
it uses more efficient encoding technology. A 96 kpbs AAC
file is similar in sound quality to a 128 kbps MP3 file.
Ogg Vorbis is another type of lossy compression and uses
.OGG as the file extension. It is an open-source product
and unlike MP3, there are no patent restrictions on its
use.
Lossless Compression
For the audio purist who insists on the best quality
sound possible, lossless compression offers CD quality
sound. The tradeoff is larger files sizes while
MP3 can compress audio in the range of 80% - 90%,
lossless compression typically compresses the file by
half.
Popular lossless formats include FLAC, Monkeys
Audio, and SHN (Shorten). These formats are supported by
many audio players and are popular for archiving CD
collections as well as for trading music.
About the author:
Hans is editor of the Audio
Howto Section of the Selected
Audio Review Guide
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