Alternatives to Digital Audio
Sunday, 06.24.2007, 11:09pm (GMT)
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, Monkey’s 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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