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MP3 - MPEG-1 Layer III (or MPEG Audio Layer III)
MP3 was introduced as a part of the official
MPEG-1 standard in 1992 and until today it is the most
successful audio-standard since WAV. The german Fraunhofer
Gesellschaft (FhG), which has developed this audio-compression
still holds the key patents the MP3-techology inherits.
The development started back in 1987 at the Fraunhofer
Institut Integrierte Schaltungen as project EUREKA
EU147. The final compression algorithm became later
known as MP3. In April 1989 Fraunhofer applied patent
on MP3 in Germany and it became part of the MPEG-1 standard
in 1992. It was in january 1995 when Fraunhofer applied
patent on MP3 in America as well and it was granted
in November 1996. Using MP3-compression PC-users were
able to compress an ordinary music-CD to one tenth of
it's original size - thus 12 hours of music could be
stored on a recordable CD that on the other hand could
be played by a MP3-CD-player or an ordinary PC. What
made MP3 that popular in the end was the online peer-to-peer
program named Napster. Millions of songs were exchanged
every day via the popular program. That was solely possible
by MP3, because conventional formats such as WAV or
AU were way to big in size with similar quality. MP3
also offered like WMA later the big advantage of being
streamingable (not all of the file has to be downloaded
to listen to it).
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WMA - Windows Media Audio
Microsoft's respond to MP3, the Windows Media
Audio-standard. As it is part of the Windows Media package,
Windows Media Audio 8 was presented in early December
2000 and it is until now the best Windows Media product.
Windows Media Audio among other things is firmly integrated
in Microsoft's Windows Media Player.
Microsoft promises with this version almost CD-quality
with just a third of the source-file's size.
Above all WMA offers the advantage that copyright-protected
songs cannot be published any further (Digital Rights
Management). That's not the only reason why many music-
and movie-corporations meanwhile decided in favour of
WMA instead of MP3. Like MP3 WMA is almost predestined
for the internet by offering streaming capabilities
(see MP3 for details) both with WMA and WMV (Windows
Media Video).
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OGG
The development of the OGG standard began in
1993, then known as "Squish". OGG was right from the
start an open source project and hence is free of any
patents. It was designed as a substitute for MP3 and
WMA and by now it is almost as popular and well known
as MP3. Above all, the algorithm is still being developed
what is mainly due to its flexibility. Although the
sound-quality gets better with every further development
the files are backwards compatible and can be played
with older players as well. Like MP3 OGG offers encoding
at variable bitrates. Using this compression parts of
the song are encoded with a higher compression than
others what depends on the source. Most times, this
compression goes along with squishy noises or even small
interruptions. OGG is also one of the very few formats
that support multi-channel compression. Surround-files
could theoretically be compressed with more than two
channels. OGG is, like it's predecessors, streamingable
and although the used player has to support this feature,
it's one of many good reasons for OGG.
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VQF
It was back in 2000 when another audio-standard
was "given birth" and since then struggles for the users'
favour. VQF however suffers mainly of two things: first
it is hardly known anywhere and second it takes the
PC about three to four times longer to convert a song
in VQF than in any other format.
At a bitrate of 80 kbps VQF promises the same quality
MP3 does at 128 kbps - this would mean that VQF-files
would take 30 % less space. Unfortunately it takes twice
the CPU-capacity to play VQF than MP3.
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mp3PRO
mp3PRO is the next generation of MP3. A divison
of the Fraunhofer Institute is working on this
together with Thomson multimedia. mp3PRO is said
to offer the same quality of MP3 at half the file size.
This is achieved by a further compression of a tone's
high frequencies. This SBR (Spectral Band Replication)
is believed to be almost loss-less and represents the
PRO in the name. Sooner or later mp3PRO will take the
place of MP3 as a common standard. Like WMA mp3PRO is
backwards compatible, that means mp3PRO-files can be
played with common MP3-players. These files however
sound very dull and rustled. In 2005 the new format
was first presented to the public - now like WMA equipped
with a watermark for copyright-protected files. Whether
mp3PRO is to take the place of the worthwhile proven
MP3 - no one knows; it's advantages to portable MP3-players
are obvious. Streaming capabilities surely prepare mp3PRO
for the internet as well.
This format is still being developed. A final release
is expected for the end of 2005.
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AAC - Advanced Audio Coding
After MP3's marvelous success especially with
the internet-users, the limits of this new format unveiled
quite soon: in lower bitrates MP3 rapidly lost quality
although the file size was reduced remarkably. This
is where AAC comes in. Also developed by the Fraunhofer
Institut the format was meant to be MP3's successor.
However the aim was not achieved, even at 96 kbps a
heavy loss of quality is noticable. Maybe that's why
AAC is hardly known anywhere, although it was introduced
in 1999. Above all there are hardly any software-players
that support AAC.
Due to these restrictions AAC was not considered in
these test. Some helpful homepage-links dealing with
AAC can be found in the links-column.
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WAV
One of the first audio-standards; WAVE-files
are virtually of the same quality as data on audio-CDs
and therefore offer the best quality. At the same time
these files are very large (10 MB / min.), that's why
they are unsuitable for everyday exchange via the internet.
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