The Optimization Of Wireless High-definition Video Compression Algorithm For Real-time Transmission

With the popularity of mobile terminals and the rapid development of wireless communication technology, "high-definition" and "wireless" has become a hot research technology currently. More and more high-definition multimedia devices connected by wireless channel, the layout of these equipments become more simple and convenient. But with the sharp increase of the data of HD video transmit in the wireless channel, video compression is essential,H.264/AVC is one of many efficient HD video compression standards. H.264/AVC can provide high quality video images in a variety of bit rate, has adaptive delay characteristics, supports a variety of video applications, has strong fault tolerance ability, the compressed video bit stream is suit for transmitting in the wireless channel. But the hardware resource and computing capacity of the mobile terminals is limited, and the bandwidth and transmission rate of the wireless channel is also limited, further optimization of the H.264/AVC algorithm to solve the above problem has important application value.Firstly this paper introduces several common wireless HD video real-time transmission systems, expounds the wireless transmission technology and the video compression technology used in these systems. In order to make the HD video can be efficiently compressed, realize the real-time transmission in wireless channel, in-depth study intra prediction and inter-mode selection these two key technologies of the H.264/AVC video coding standard, analyze the important of these two key techniques in H.264/AVC video coding standard and the deep reason why they have great computational complexity. Then beginning from these two key technologies,simplify framework of H.264/AVC and optimize its algorithm, to improve the coding efficiency and reduce the design difficulty, improve the real-time performance. For intra prediction,compared with intra full search algorithm, this paper puts forward a wireless HD video intra prediction algorithm based on the flatness of the images; For inter-mode selection, this paper proposes a fast inter-mode selection algorithm based on global and local residual complexity.Through the H.264/AVC standard test model JM18.4, do compression test for 8 video sequenceswith different motion vector, the results show that the PSNR and bit rate of the image encoded by the proposed algorithm basically unchanged, but the intra encoding time is reduced by 45%than the original model and the inter encoding time is reduced by 55% than the original model.The proposed algorithm improves the coding efficiency effectively, makes the encoded video stream transmission between the mobile terminal and the large screen television have better real-time performance.