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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. |