A TMO-based approach to tolerance of transmission jitters in tele-audio services

One of the key issues in multimedia processing, especially, in distributed processing of multimedia data streams on a network of computing platforms, is still the accurate maintenance of the temporal relationship among data elements of various media types [Aya01, Bla96, Cel00, Her98, Hun01, Ste96, Bla96, KSK02]. Moreover, the amount of effort consumed by the designer and the programmer in the specification of such temporal relationship and programming of the processing steps to maintain the relationship among the processed data elements has become a major issue confronting the community engaged in multimedia software technology research [Aky96, Bat99, Bai98, Gib95, Kas01, KDH02, Lia01, Ste96, Xie99, Zan95]. A multimedia data stream transferred from a source node to one or more sink nodes consists of consecutive logical data units (LDUs). In the case of an audio stream, LDUs are periodically captured individual samples or blocks of samples transferred together from a source to a sink(s). The data elements in a stream must be presented, i.e., replayed, at a sink node in a manner exhibiting the same temporal relationship which existed among the data elements when they were captured at the source node. Timing the movement (or play) of each data element to maintain a desirable temporal relationship among the data elements in a single data stream is called the intra-stream synchro n i z a t i o n [Jef95, Kad96, Kan01,Moo98, Ram94, Sre00]. The temporal relationship maintenance must also be applied to related data streams. One of the most commonly encountered situations where such a requirement is evident, is the simultaneous playback of audio and video with the l i p s y n c h r o n i z a t i o n [Liu96, Owe99, Xie99]. If both media are not played with good synchronization, the result will not be of acceptable high quality. In general the inter-stream syn -