Research On Wireless Streaming Media Reliable Transport Scheme And Media Stream Multiplex Method

The combination of streaming media and wireless access technology has become one of the hotspots of present research and development because of the advantage in providing convenient and abundant multimedia information service for customer individually. However, the way of improving transport quality of wireless streaming media is an urgent and challenging problem due to the high bit error rate and instability of wireless channel. In order to strengthen core competency and independent development ability in national source coding standard area, Chinese government approved and founded digital audio video coding standard workgroup of China (AVS), main task of which is researching and formalizing AVS standard with own copyright. Supported by the national high technology research and development program of China (863 Program) "Digital audio video coding transport testing and application demo system"(No.2002AA119010), this dissertation introduce the work which focus on the research area tightly related to the two main object of the program, which are Joint source channel coding technology and distribute wireless streaming media application demo system. A new reliable transport scheme for wireless streaming media and the systems media stream multiplex method of AVS standard are proposed in this dissertation. Considering the disadvantage of traditional transport protocol, for example, the high design complexity of application layer and non-guarantee of QoS, and also with a analysis of wireless streaming media and current efficient coding and error control technology, a reliable transport scheme for wireless streaming media which support protection granularity differentiate and adjusting is proposed in this paper. Combining with the interweave and RS code, the Unequal Erase Protection (UEP) scheme is achieved based on distinguishing the data importance level; The scheme realize segment/assemble of data from application layer, support adaptive adjusting of protection granularity according to channel status, enhance the function of transport layer, simplify the design complexity of application layer, and improve QoS of wireless streaming media with flexible error protection. The scheme is compatible with current transport protocol that designed based on ALF principle. In Consideration of multi-factor like industrial realization and market influence, AVS standard decided to adopt the plan of audio and video stream multiplex which based on MPEG-2 systems standard to keep the compatibility of AVS with MPEG-2 systems standard. A related solution is given in this dissertation, in which some amendment is made based on analysis the multiplex mechanism of MPEG-2 systems standard, including adding a new video descriptor for AVS video stream and related stream type and descriptor tag definition. This scheme has been adopted by AVS standard and was verified by AVS standard prototype system, the result indicated that it has solved the compatibility problem efficiently.