H.264-based Fgs Video Coding Algorithm

With the development of multimedia network, the goal of video coding have been changed from storage-based to transmission-based, it put forward a great challenge for current video coding technology and network transmission technology, among them, the fluctuation of network bandwidth is a fundamental problem need to be solved. The traditional scalable video coding mathod used to solve the problem are Broadcast and Streaming-conversion, but the bitrate of these two methods are restricted in several specific bitrate, and difficult to switch it dynamic during the transmissing, so it couldn't match the change of network bandwidth very well. To solve these problems, fine granularity scalable video coding technology arises at the historic moment. The video which coded by FGS technology can match the change of network bandwidth very well, but this will reduce the coding efficiency.To improve the efficiency of FGS video coding, three methods are put forword in this paper. First, analysed the relative merits of one-loop arithmetic, and in the base of keep the information of enhance layer add to the base layer which can increase the coding efficiency through use the higher quality patulous base layer, we put forward two methods to increase the coding efficiency of ROI(region of interested) and improve the subjective quality. Using the effective channel resources and stream resources, we proposed the methods of introducting skin-color choice algorithm and macroblock segmentation algorithm to selective the region of interest adaptive to increase the coding efficiency of ROI and improve the subjective quality by upgrading the bit-panle,preferred coding and transmission the ROI at the same time. Secondly, analysed the relative merits of two-loops arithmetic, and in the base of keep the loop of motion compensation to increase the efficiency of enhence layer, we proposed the method of improvement of FGS which based on the two-loops, in this method, we merge the module of motion estimation of the enhance layer and base layer to reduce the coding complexity, coding time and introduct the enhance layer information which can decode correctly to base layer to increase the coding efficiency and improve the subjective quality of video through use the higher quality patulous base layer. From the simulation results of the PC machine, we can know that the methods proposed in this paper can not noly increase the coding efficiency of FGS, but also can improve the subjective quality of video.