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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).
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).
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.
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.
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 2001 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
2001.
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.
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.
Source:
LitexMedia Inc.
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