Reducing the number of tested modes for inter mode decision in H.264/AVC and accelerating with multithreading

Mode decision at the encoder processing of H.264 is a bottleneck due to its time complexity. In this paper, we propose a new method to reduce the original 7 inter modes to 3. In particular, we identify the smallest 2 light-weight costs of inter modes, and check if they are neighbors or not, to determine whether to save or discard some of the modes. We also parallelize a part of the code to speed up the executing time. The experimental results demonstrate that the proposed methods improve the performance in terms of executing time, regardless of the video types in consideration, and still keep almost the same video quality with almost no change in encoded video size.