Fast mode decision algorithms for inter/intra prediction in H.264 video coding

In this paper, we propose fast mode decision algorithms for both intra prediction and inter prediction in H.264. In order to select the candidate modes for intra4x4 and intra16x16 prediction efficiently, we have used the spatial correlation and directional information. We have also applied an early block size selection method to reduce the searching time further. The fast inter mode decision is achieved by an early SKIP mode decision method, and a fast mode decision method for 16x16 and P8x8 modes. Extensive simulations on different test sequences demonstrate a considerable speed up by saving the encoding time up to 82% for intra prediction and 77% for inter prediction on average, compared to the H.264 standard, respectively. This is achieved at the cost of negligible loss in PSNR values and small increase in bit rates.