The achievements of MPEG-1

The achievements of MPEG-1

Besides being an excellent set of pieces of technology, MPEG-1 is also a remarkable collection of “first ever” achievements. 

It was the first integrated audio-visual standard. This was a great achievement and did set an example to the media industry. For the first time a standard had been produced where the individual pieces were highly optimised because the best specialists in the field had developed them. Still the individual pieces fit well together, because during the 4 years it took to develop MPEG-1, countless “joint meetings” between the different groups had identified the issues that prevented smooth integration the three parts of the standard and smoothed out all the differences. This is a practice that continues to this day where at every MPEG meeting possibly tens of break-out groups and joint meetings involving two and sometimes more than two subgroups take place. MPEG-1 also set an organisational example for companies. Before MPEG-1, the audio and video groups in all standardisation bodies and most research institutions were usually allocated to different parts of the organisations, but today most of them are – as they should always have been – together from an organisational viewpoint. 

MPEG-1 was also the first standard that defined the receiver and not the transmitter. If the way information is encoded is undefined, obviously within the syntactic constraints of the standard, then the standard becomes a level play field where different manufacturers can compete and provide better and better encoding equipment. This will prolong the life span of the standard, whose obsolescence will be decreed only when the encoder optimisation scope will have been exhausted and a new, more powerful, standard can be produced using new research results. 

MPEG-1 was also the first standard designed to code the video signal independently of the video format (NTSC/PAL/SECAM). I do not claim that this was particularly relevant technical achievement, I only mention it because it was a policy decision of other Standard Developing Organisations (SDO) not have the foresight or – better – the courage to implement because of the highly political meaning attached to anything related to video formats. Indeed the digital version of these video formats has the same sample rate that can be generated by the same decoding device. The display issue is left out of the standard. 

MPEG-1 was also the first standard that was developed jointly by all industries with a current, or even expected, stake in the audio-visual business, overcoming their traditional entrenched interests.

MPEG-1 was also the first media-related standard that was developed entirely using software tools and also produced a reference software implementation of the standard.

Lastly, MPEG-1 was the first standard for which a quality performance was assessed at the completion of the work (actually, for MPEG-1 this was done only for the audio part). 

But next to the congratulations for the excellent technical work done and the number of records set, it is also important to make a dispassionate analysis of how the original business goals that the companies had with MPEG-1 have been achieved through the standard. 

The driving idea of MPEG-1 – interactive video applications on compact discs – was a very natural move. Jointly launched on the market 5 years before by Philips and Sony, CD Audio was (and still is, through its successors DVD and Blue-Ray) a roaring – if nowadays declining –

success. The specification of CD-ROM as a computer peripheral (ISO/IEC 9660) that enabled users to have hundreds of Mbytes accessible from their computers was already completed. This was something like a dream at a time when hard disks had a capacity of (very) few tens of Mbytes. Everybody believed that, if only digital video could be brought down to a bitrate that could fit in the 1.41 Mbit/s transfer rate of the CD (or 1.2 Mbit/s of the CD-ROM, single speed at that time!) and preserve a sufficiently high quality, great opportunities were waiting for CE devices, telecommunication terminals, PC peripherals, etc. The typical stand-alone device was what eventually became Compact Disc Interactive (CD-i), the interactive video device par excellence manufactured by Philips. 

With the addition of audio coding work in the MPEG work program, CD-i like devices could benefit from better audio (the original CD-i specification had quite a primitive form of audio), but exciting audio-only applications could be imagined as well. The first idea was to replace inexpensive audio-only analogue recording devices such as the Compact Cassette (CC) players with equally inexpensive analogue and digital recording devices that still used the CC mechanics as the recording medium. Eventually this idea became a product called Digital Compact Cassette (DCC), manufactured by Matsushita and Philips. The second idea was to introduce a new fully-digital audio broadcasting system, the target of Eureka 147 DAB that was eventually deployed in Europe, Canada and other countries. 

The reader who happens not to know any of these three acronyms – CD-i, DCC and DAB – should not feel embarrassed. The first product was discontinued several years ago. The reasons are manifold, but the primary one is that periodically the IT mermaid sings her interactive song and some companies get fancied by it. But when the mermaid achieves that, she casts them aside. The second product looked like a great idea: billions of compact cassettes used to be sold but the quality was not what ears, accustomed to compact disc, would want. What if we had a system where people could keep on using the same carrier – the cassette – as the old analogue device but also record and play back compressed digital music at a quality indistinguishable from the CD’s? No way, consumers did not buy it, and the reasons were not technical. The third, broadcasting of digitally compressed studio-quality sound, also looked like a new lease of life for good old radio. The reality of today, several years after the service has been launched, is that other forms of digital radio have taken hold, but DAB is not having a prosperous life. 

So much for the ability of industries to guess what consumers want and provide SDOs with precise directions about what standards they need. If MPEG had designed its MPEG-1 Video and Audio coding for those specific industry needs, probably the name MPEG, if still existing, would not be linked to the idea of products based on successful standards. If it does, it is because MPEG, while valuing industry inputs, made its best efforts to develop “generic” standards by abstracting its requirements from the specific industry requests of the time. 

MPEG-1 is a successful standard. Video Compact Disc (VCD) is a product that plays linear video recorded on a CD as MPEG-1 with a quality comparable to VHS’s. Hundreds of million VCD players have been sold, especially in the Far East and many billion VCDs have been printed. MPEG-1 was the first audio-visual format for the Personal Computer. Since Windows 95 all versions of Windows have had an embedded MPEG-1 software decoder. Even portable video cameras recording in MPEG-1 were manufactured. MPEG-1 Audio Layer II is used in hundreds of million digital television Set Top Box receivers. An entire new industry, the VLSI industry for digital audio and video was created by MPEG-1.

Lastly I must mention MPEG-1 Audio Layer III, aka MP3. Billions of people use it and it would probably require a big effort to identify all companies manufacturing hardware or software MP3 players. But MP3 is another story. Like Mark Twain, I am not going to tell you the story this time, but, unlike him, I will just keep it for a later page.

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