Fraunhofer Institute for Integrated Circuits IIS
Fraunhofer Institute for Integrated Circuits IIS

Development

The story began at the end of the 1970s with the idea of sending music signals over telephone connections.

 

In 1987, the University of Erlangen-Nuremberg and Fraunhofer IIS joined forces in a research alliance as part of the EU-sponsored EU147 EUREKA project for Digital Audio Broadcasting (DAB). This yielded the first milestone: the LC-ATC codec (low complexity adaptive transform coding) that allowed for real-time encoding of stereo music.

Ernst Eberlein: “Before that LC-ATC existed only as a computer simulation, and it took high-performance computers hours of work  to test the technique. With the real-time codec, we were able to test LC-ATC under real conditions and make significant improvements to the algorithm.”

 

Developing the OCF algorithm (optimum coding in the frequency domain) was a further milestone . OCF already bore many of the hallmarks of the future mp3 codec. With a few enhancements, the basic structure of the OCF was made into a feasible technique.

Karlheinz Brandenburg: “The development of OCF in 1988 was an important milestone because it brought to fruition the 1970s vision of transmitting music over telephone connections. For the first time we were able to encode music in good quality at 64 kbit/s for a mono signal. OCF was the beginning of the road to MPEG standardization.”

 

In 1989, the Moving Picture Expert Group (MPEG), an international standardization organization, was planning to introduce an audio standard, and OCF was put forward. MPEG received a total of 14 audio coding proposals, and the participants were encouraged to combine their contributions. This resulted in a total of four potential candidates, two of which were MUSICAM from the Institute for Broadcasting Technology IRT and Philips, and ASPEC (adaptive spectral perceptual entropy coding). ASPEC was the result of further improvements to OCF by Fraunhofer IIS in addition to contributions from the University of Hanover, AT&T and Thomson. Following exhaustive testing, MPEG proposed combining MUSICAM and ASPEC in establishing a family of three coding techniques: layer 1 would be a low-complexity variant of MUSICAM; layer 2 would be a MUSICAM coder; and layer 3 (later called mp3) would be based on ASPEC. The technical development of the MPEG-1 standard was completed in December 1991.

Bernhard Grill: “The crucial success came in 1992, when our technology was incorporated into ISO MPEG standardization. In the face of international competition, we were able to demonstrate – with tests conducted by independent institutions – that our technique was technologically superior to all the rest. That was our one goal throughout, and we sacrificed many an evening and weekend to achieve it.”

Layer-3, which is the most efficient and complex of the three codecs, is integrated into commercial applications in the areas »musical transmission over ISDN telephone lines« and »voice announcement systems for local public transport«. The codec is also applied to pilot projects to save music on relatively small computer hard drives and transmit music data over the small computer modems with 28.8 kbit/s.

In 1995, mp3 received its current name after it was unanimously selected in an internal poll by Fraunhofer researchers.

The era of transportable mp3 players began in 1998 when MPMAN by Saehan Information Systems was introduced in Korea and Rio by Diamond Multimedia in the United States. The increasing popularity, decreasing costs for storage space and the proliferation of the Internet lead to dozens of companies creating and launching similar devices.

Heinz Gerhäuser: mp3 was a revolutionary technology at just the right time. Not long after the development of mp3, high-performance computers were launched, the price for storage space was decreasing and the Internet expanded. Thus, the technological predispositions for commercial success were there. Now all we had to do was demonstrate to the world what the new mp3 technology could be used for.

Heinz Gerhäuser: "mp3 was a revolutionary technology at just the right time. Not long after the development of mp3, high-performance computers were launched, the price for storage space was decreasing and the Internet expanded. Thus, the technological predispositions for commercial success were there. Now all we had to do was demonstrate to the world what the new mp3 technology could be used for."

From file extension to brand

In an internal survey conducted in 1995, Fraunhofer researchers unanimously agreed on “.mp3” as the file extension for MPEG Audio Layer 3. Here is the translation of the original text of the email with which the result of the poll was made public:

Date: Fri, 14 Jul 1995 12:29:49 +0200
Subject: File extension for Layer 3: .mp3

Hello,
In light of the overwhelming consensus of the survey participants, the file extension for ISO MPEG Audio Layer 3 is .mp3. That means we should take care to no longer use any .bit suffixes for upcoming www pages, shareware, demos etc.
There’s a good reason, believe me :-)