ADAPTIVE PRUNED 4 × 4 DCT ALGORITHM FOR H.264

A new integer 4×4 transform is adopted in the new video coding standard H.264/AVC. To reduce the computation load of the new transform, the SSAVT model for 8×8 transform is applied into H.264 4×4 transform with some modifications. Then, three classes of pruned block are defined and the corresponding simplified butterfly computation processes are designed. Furthermore, a fast DCT algorithm is proposed, with which we can identify the class of pruned block, so as to adopt simplified computation, with the help of modified model for 4×4 transform. Simulation results show that the proposed DCT algorithm saves about average 55% computation of DCT compared with full computation.