Fast Mode Decision Based on Mode Adaptation

This paper proposes an efficient algorithm for fast mode decision in H.264/advanced video coding by adaptively predicting the optimal mode for each macroblock (MB) to be coded. Firstly, encoding modes are projected as points onto a 2-D map, and an optimal 2-D point of the MB to be coded is predicted based on the encoding information of spatial-temporal neighboring blocks. Then, a priority-based mode candidate list with a descending order to be the best mode is constructed based on the optimal 2-D point. Finally, mode decision is performed according to the priority-based mode candidate list in the checking order, from the most important mode to the least one, with early termination conditions. Extensive experimental results demonstrate that the proposed algorithm is superior to three recent fast mode decision algorithms, with the entire encoding time being reduced by about 60% for quarter common intermediate format/common intermediate format/standard-definition sequences on average and the rate distortion performance being kept almost intact.