Research Of Scene Change Rate Control Algorithm Based On H.264/AVC

H.264/AVC video coding standard was developed jointly by the ITU-T and ISO/IEC. By adopting various advanced coding techniques, H.264/AVC gains a significant improvement in compression performance and network transmission while comparing to other ever existing standards before. So this standard obtains great attention from academic and industrial fields. And this standard, so as to others, only defined the main framework, many detail problems still need to be solved.When transmit compressed video data, network condition and bandwidth should be considered. The aim of rate control is to regulate the coded bit stream to satisfy the channel condition and improve the reconstructed video quality.In this dissertation, the coding strategy and techniques in H.264/AVC are explained. Research focus on rate control algorithm in scene change condition.Scene change happens frequently in video. Based on several classic scene change detection methods, a method by estimating the absolute sum of DCT coefficient to determine where scene change happens is proposed. In experiment the entire scene change frames have been found out.Based on the research of key technology and typical algorithms of rate control, as the rate control algorithm of H.264 lacks corresponding treatment in scene change condition, a rate control algorithm with scene change detection in frame level by estimating the absolute sum of DCT coefficient and corresponding adjustment after detection is proposed. This algorithm is implemented in JM86 (H.264/AVC),according to the test results, by using the improved algorithm, the average PSNR and actual bit rate of the test sequences is improved.