H.264/AVC employs variable-size motion compensation with multiple reference frames that can significantly improve the coding performance compared with the previous video coding standards.
However, the computational complexity of the H.264/AVC encoder increases dramatically due to the various size modes used. One of the most challenging problems in implementing this encoder is mode decision. We propose a novel intermode decision algorithm (NIMDA) to reduce the candidate mode set, which utilizes two basic elements, the sum absolute difference (SAD) of each 4×4 block from the initial test of the inter-16×16 and the texture characteristic. Simulation results show that our proposed algorithm can save about 46% in computational complexity, with negligible loss of coding efficiency.