Interface[s] Montréal

Mobility

Stéphane Coulombe

École de technologie supérieure(ets), Department of Software and IT Engineering

Multimedia adaptation and transcoding for mobile applications

View the presentation [In French]

Because of the fast pace of technology evolution and mobile terminal market segmentation (different models addressing different user needs), their characteristics are very diverse. They support different multimedia formats and have different amounts of memory, processing power, and screen resolution, etc. As a result, efficient access to multimedia content and interoperability between mobile terminals is seriously compromised. A solution to such problem is to adapt or transcode, most often in a server, the multimedia content, to meet the specific characteristics of each terminal. This presentation will provide an overview of the applications requiring adaptation. It will then present the architectural elements of an adaptation system and existing technologies available to develop such a system (e.g. UAProf and the Standard Transcoding Interface). Some highly efficient image and video transcoding algorithms are then presented. These algorithms perform transcoding in the DCT domain and provide significantly improved performance compared to the straightforward full decoding, processing and re-encoding. Finally, current research areas in the field of multimedia adaptation are presented.

Stéphane Coulombe is a Professor in the Department of Software and IT Engineering at École de technologie supérieure. He received a B.Eng. degree in electrical engineering from École Polytechnique de Montreal in 1991. He received a Ph.D. degree in telecommunications from INRS-Telecommunications in 1996. He received several awards including an Academic Medal of the Governor General of Canada. He worked for the Wireless Speech Processing group of Nortel Networks in Montréal as a member of the scientific staff where he implemented various speech components that are part of Nortel product portfolio for voice over IP. He joined the Nokia Research Center in 1999 (in the Audiovisual Systems Laboratory, Texas) where, as a program manager, he led the research and development activities related to media adaptation and transcoding for applications including MMS, SIP messaging, and browsing. His contributions are part of various Nokia products, including the MMSC.