Research And Implementation Of Audio And Video Synchronization Based On Timeline Model

With the development of computer technology and the popularization of the stream media, traditional technology of multimedia is not suit for the development of internet anymore, especially the network available bandwidth is not enough, the transmission and synchronization of multimedia have become the hotspot of research. As a key technology in multimedia communications, because of the technology of media data collection, compression code and network transmission has been relative mature, this paper will mainly deals with the control of audio and video synchronization in receiver.This paper detailedly analyzes the existent synchronization methods at present, and investigates the suitable solution for this system, and then brings forward a relative time-stamp synchronization scheme based on feedback control without synchronous clock of whole power. This scheme puts all the media unit which are composed media object on a interrelated time scale, and the position of media unit determines its interrelated time-stamp, and then the media unit which has the same time-stamp will be displayed at the same time in order to achieve inter-media synchronization. Thus, this scheme just guarantees the time-stamp relative synchronization between the audio and video frame and dispenses with complex means getting exact time value corresponding to time-stamp, so it reduces the complexity of getting time synchronization message and the difficulty of maintaining public time axis. Besides, when played in receiver, audio is as primary media and video is as subsidiary media, by comparing to the time-stamp of audio and video frames and throwing away or repeating playing certain video frame to achieve inter-media synchronization. Furthermore, this paper implements the function of self-feedback-regulation, so it can avoid the phenomena of unable guaranteeing the quality of playing, because, if without the function of self-feedback-regulation, when the velocity of sending or playing is too fast or too slow , the burden of system would be over weight even congestion result as data lost. Addition, the architecture and the modules are implemented, and some flow charts and code are given in this paper. Software implemention are composed of two modules, one is the module of synchronization disposal in sender and the other is the module of synchronization disposal in receiver. Synchronization disposal in sender is composed of data collection, time-stamp s disposal and sender velocity s control, and synchronization disposal in receiver is explained from two aspects: intra-media synchronization and inter-media synchronization, and composed of following modules: getting rid of jitter, detecting, feedback-regulation, and synchronization playing, thereinto, inter-media synchronization is the emphases and difficulty part in synchronization disposal in receiver, and so in this paper is.