Research On The Rate Control Algorithm Of H.264/SVC For Digital Home Multi-screen Sharing System

With the development of technology, a variety of smart appliances constantly enter millions of households, because these appliances can’t be interconnected, a large amount of storage resource is wasted. To solve the problem, people propose the digital home concept. As one of the typical applications of digital home, multi-screen sharing system aims at helping users to access their media resources stored on different appliances whenever necessary.So far, the multi-screen sharing system doesn’t has good the network adaptability and has long delay time, so the users always obtain poor experience. Rate control is an indispensable part of the video transmission system, and it makes the video transmission have dynamic adaptability and shorten the delay time. ITU-T/ISO develops the H.264/SVC based on the H.264/AVC. Because the H.264/SVC has the scalability mechanism, it can produce a bitstream which could support different frame rates, resolution and video qualities. Compared with H.264/AVC, H.264/SVC not only has high coding efficiency, but also has better network adaptability. But the rate control algorithm adopted by the H.264/SVC only applies to the base coding layer, and H.264/SVC doesn’t provide an effective rate control algorithm to apply to the enhancement coding layer. We improve the rate control algorithm for the H.264/SVC to make it apply to the enhancement coding layer. A multi-screen sharing system based on H.264/SVC is designed and implemented in paper.First, the features of temporal, spatial, quality scalability and the core coding tools in H.264/SVC are introduced briefly. And the classical rate control algorithm of the past coding standards and the rate control algorithm based on Lagrangian optimized algorithm in H.264/AVC are described.Second, the rate control algorithm in the reference software JSVM of the H.264/SVC is researched and analyzed. And the paper focuses on analyzing the key effect of the initial quantization parameter on the rate control algorithm. For multilayer coding structure of the H.264/SVC, a multilayer adaptive initial quantization parameter calculation method is proposed. The algorithm is based on the content of video and the network characteristic.In addition, the multi-screen sharing system platform based on H.264/SVC is designed and implemented on Android system. And the proposed algorithm is tested on the multi-screen sharing system platform based on H.264/SVC. Experimental results show that the proposed algorithm makes the video display smoother and the video picture have better quality.