Saturday, February 24, 2007

Multimedia Communication for Universal Media Access (UMA)


Universal (Multi-)Media Access (UMA) is a buzzword which is well known within the respective community since about 1999 when J.R.Smith brought it up in one of the first arcticels of IEEE Transactions on Multimedia. With the InfoPyramid a concept was born which allows one to provide different versions or even modalities of the same multimedia content for different end user terminals, network characteristics, or user preferences.

UMA's slogan is to "provide access to advanced multimedia content anywhere, anytime, and with any kind of device".

The aim of this blog is to provide news, trends, and relevant information regarding multimedia communication and related standardarization actitivities, e.g., IETF, W3C, and MPEG.

Adaptation: Why and How?

Given the amount of multimedia formats, heterogeneous network infrastructure, and the plethora of devices gaining access to multimedia content encoded by using these formats, it becomes naturally that some kind of mechanism is required which provides a solution to accomplish this mismatch. This mechanism or concept is referred to as adaptation.

The Concept of UMA

The adaptation paradigms that evolved during the last decade can be clustered into three categories:

  • Adaptation by Selection uses pre-stored versions of different qualities and/or modalities of the same multimedia content and delivers the most suitable version depending on the usage environment where the content is going to be consumed.
  • Adaptation by Transcoding/Transmoding provides an "on-the-fly adapted" version of the original multimedia content according to the different contexts of multimedia consumption.
  • Adaptation by Transformation facilitates scalable coding formats and bitstream syntax descriptions enabling the adaptation of the multimedia content by performing simple truncation operations and minor update operations in a coding format-independet way.

The above paradigms have, of course, their pros and cons and those who are further interested should check out the articels and links in the next section.

Further reading and links:

[1] R. Mohan, J.R. Smith and C.-S. Li,, "Adapting Multimedia Internet Content for Universal Access," IEEE Trans. Multimedia, vol. 1, no. 1, pp. 104-114, March 1999.

[2] C. Timmerer and H. Hellwagner, "MPEG Standards enabling Universal Multimedia Access", 1st International Conference on Automated Production of Cross Media Content for Multi-channel Distribution, Florence, Italy, November/December, 2005.

[3] C. Timmerer and H. Hellwagner, "Interoperable Adaptive Multimedia Communication, IEEE Multimedia Magazine", vol. 12, no. 1, pp. 74-79, January-March 2005.

[4] IEEE MultiMedia Magazine

[5] IEEE Transactions on Multimedia

[6] IEEE Transactions on Circuits and Systems for Video Technology

[7] ACM Multimedia Systems

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