Improvement Of Motion Compensated Prediction With Weighted Estimation In H.264

H.264/MPEG AVC is the international video coding standard including weighted prediction character (WP) and it is widely used in many kinds of video coding. There are WP both in the main profile and extended profile of white paper of H.264. When using motion-compensated estimating it is essential to multiply a weighted factor and add a supplemental amount. The paper provide the improvement of design feature of H.264 WP:the explicit mode in one direction of P frame, the implicit mode in two directions of B frames. In explicit mode, for each permitted reference picture index, weighted factor is inferred from the ratio of reference picture and current picture's corresponding vectors. Supplemental amount is computed from the difference of reference picture and current picture's corresponding vectors. Then they are coded in slice header. In implicit mode, weighted factor can be inferred from the relative order distance of the two reference picture and it is not stored in slice header, also supplemental amount is not used. Now in this paper, the WP character of H.264 standard is described, and two modes of weighted prediction:explicit mode and implicit mode is provided. There are C codes to implement the improving algorithym. The experimental result is to prove the improvement of coding picture SNR when using improving WP algorithym.