About MP3s and the Development of MP3s

The encoding of the MPEG-1 Audio Layer 2 began as the Digital Audio Broadcast (DAB). The project was managed by Egon Meier-Engelen of the DFVLR in Germany, which was later known as DLR (Deutsche Luft und Raumfahrt = German Aerospace Agency). Egon Meier-Engelens project was financed by the European Union as part of the EUREKA program, which was commonly known as EU-147. EU-147 which ran from 1987 to 1994.

There were two proposals available in 1991: ASPEC (Adaptive Spectral Perceptual Entropy Coding) and Musicam (Which was known as Layer 2). The Musicam system, as projected by Philips (The Netherlands), CCETT (France), IRT (Germany) was selected due to its straightforwardness, as well as its low computational authority which linked to the encoding of high quality compressed audio. The Musicam system which was based on the sub-band coding was the key to settle the basis of the MPEG Audio compression format because of its excellent sampling rates, structure frames, outstanding headers and its number of samples per frame.

All the results and technologies of the Musicam ideas were fully included into the definition of the ISO MPEG Audio Layer 1 and 2 and then further on to the Layer 3 or better known as MP3 format. Under the watchful eye of Professor Mussmann from The University of Hannover, the control of the standard was made under the responsibilities of L. van de Kerkhof (Layer I) and G. Stoll (Layer II).

Later on a few men including J.D Johnston (U.S.), Yves-Franois Dehery (France), Karlheinz Brandenburg (Germany) and Gerhard Stoll (Germany) took some ideas from ASPEC and Musicam, added some of their own ideas and created what we know today as MP3, which was designed to deliver the same quality of 128 kbit/s as Mp2 at 192 kbit/s.

The finalizing of all algorithms took place in 1992 as part of the MPEG-1, the first standard set-up by MPEG, resulting in the international standard ISO/IEC 11 172-3, which was published for the first time in 1993. Later in 1994 work on Mpeg audio was finalized as part of the second set-up of MPEG standards, MPEG-2, which was more formally known as the ISO/IEC 13818-3, originally published for the first time in 1995.

Compression effectiveness of encoders are normally specified by the bit rate because the compression rate depends on the bit depth and the sampling rate of the input signal. However, there are often published compression rates that use the CD parameters as orientations (44.1 kHz, 2 channels at 16 bits per channel or 2×16 bit). From time to time the Digital Audio Tape (DAT) SP parameters are used (48 kHz, 2×16 bit). Compression ratios with this reference are higher, which shows the difficulty of the term compression ratio for lossy encoders.

A CD recording of Suzanne Vegas song, Toms Diner, was used by Karlheinz Brandenburg to assess the MP3 compression algorithm. This particular recording was chosen by Karlheinz because of the songs softness and simplicity, which made it easier for them to hear any defects in the compression format during playbacks.