MPEG-4 had the ambition of bringing interactive 3D spaces to every home. Media objects such as audio, video, 2D graphics were an enticing notion in the mid-1990’s. The WWW had shown that it was possible to implement interactivity inexpensively and the extension to media interactivity looked like it would be the next step. Hence the official title of MPEG-4 Coding of audio-visual objects.
This vision did not become true and one could say that even today it is not entirely clear what is interactivity and what is the interactive media experience a user is seeking, assuming that just one exists.
Is this a signal that MPEG-4 was a failure?
- Yes, it was a failure, and so what? MPEG operates like a company. Its “audio-visual objects” product looked like a great idea, but the market thought differently.
- No, it was a success, because 6 years after MPEG-2, MPEG-4 Visual yielded some 30% improvement in terms of compression.
- Yes, it was a failure because a patent pool dealt a fatal blow with their “content fee” (i.e. “you pay royalties by the amount of time you stream”).
- No it was a success because MPEG-4 has 34 parts, the largest number ever achieved by MPEG in its standards, that include some of the most foundational and successful standards such as the AAC audio coding format, the MP4 File Format, the Open Font Format and, of course the still ubiquitous Advanced Video Coding AVC video coding format whose success was not dictated so much by the 20% more compression that it delivers compared to MPEG-4 Visual (always nice to have), but to the industry-friendly licence released by a patent pool. Most important, the development of most MPEG standards is driven by a vision. Therefore, users have available a packaged solution, but they can also take the pieces that they need.
Figure 53 – Model of the MPEG-4 standard
An overview of the entire MPEG-4 standard is available here. The standard is composed of 34 parts, some of which are
- Part 1 – Systems specifies the means to interactively and synchronously represent and deliver audio-visual content composed of various objects (link)
- Part 2 – Visual specifies the coded representation of visual information in the form of natural objects (video sequences of rectangular or arbitrarily shaped pictures) and synthetic visual objects (moving 2D meshes, animated 3D face and body models, and texture) (link).
- Part 3 – Audio specifies a multi-channel perceptual audio coder with transparent quality compression of Compact Disc music coded at 128 kb/s that made it the standard of choice for many streaming and downloading applications (link)
- Part 6 – Delivery Multimedia Integration Framework (DMIF) specifies interfaces to virtualise the network
- Part 9 – Reference hardware description specifies the VHDL representation of MPEG-4 Visual (link)
- Part 10 – Advanced Video Coding adds another 20% of performance to part 2 (link)
- Part 11 – Scene description and application engine provides a time dependent interactive 3D environment building on VRML (link)
- Part 12 – ISO base media file format specifies a file format that has been enriched with many functionalities over the years to satisfy the needs of the multiple MPEG client industries (link)
- Part 16 – Animation Framework eXtension (AFX) specifies a range of 3D Graphics technologies, including 3D mesh compression (link)
- Part 22 – Open Font Format (OFF) is the result of the MPEG effort that took over an industry initiative (OpenType font format specification), brought it under the folds of international standardisation and expanded/maintained it in response to evolving industry needs (link)
- Part 29 – Web video coding (WebVC) specifies the Constrained Baseline Profile of AVC in a separate document
- Part 30 – Timed text and other visual overlays in ISO base media file format supports applications that need to overlay other media to video (link)
- Part 31 – Video coding for browsers (VCB) specifies a video compression format (unpublished)
- Part 33 – Internet Video Coding (IVC) specifies a video compression format (link).
Parts 29, 31 and 33 are the results of 3 attempts made by MPEG to develop Option 1 Video Coding standards with a good performance. All did not reach the goal because ISO rules allow a company to make a patent declaration without specifying which is the patented technology that the declaring company alleges to be affected by a standard. The patented technologies could not be removed because MPEG did not have a clue about which were the allegedly infringing technologies.
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