Complexity Adaptive Mode Decision Algorithm Based On H.264

Based on the new generation video coding standard, H.264/AVC becomes very popular for its efficient performance in video compression and network applicability. However, the enhancement in coding efficiency of H.264 has been achieved at the cost of a considerable increase in computational complexity, and in the society with the fast development of information processing techniques, if it satisfies the requirement of high performance video business, it should balance the relation between video's broadcast performance and compute complexity to adapt to the circumstances of low bandwidth. The main solution is to produce low complexity video encoding algorithm, which can adjust the computational complexity adaptively according to different platforms, and achieved the prefect performance. At present, the research on fast coding algorithms and complexity for H.264 have been one of the hot spot issues in both industry and academia. The following studies are performed based on the two aspects.In this paper, firstly, intra and inter prediction modes for narrowing the range of prediction modes are decided and the macro block from the spatial domain and texture correlation is considered, which reduces the number of search modes, and improve the encoding speed under the premise of good video quality. During the course of analyzing typical H.264 intra and inter prediction coding algorithm, shortcomings of some typical algorithms are summarized, and then a new algorithm based on priority decision of prediction coding algorithm is proposed.Secondly, in this paper the research is focused on the complexity adaptively under the mobile platform, based on the hand-held mobile terminals with limited energy, the relationship between complexity and energy consumption is analyzed, the constraints factors, including rate, energy supply, and coding distortion are considered, and then a complexity-rate-distortion cost function model is put forward, which achieves the balance between the energy consumption and rate-distortion. Based on the research mentioned above, an optimized complexity distribution algorithm is proposed in this paper. it is the intra and inter prediction algorithm which can control the frame rate and complexity, allot complexity reasonablely according to the energy feedback. The algorithm can adjust the computational complexity adaptively according to the change of calculation capability or power consumption of terminal processor. Finally, the algorithm is simulated in the smart phone simulator on the thought of the calculation capability and energy consumption of smart phone, and the results validate the feasibility of the algorithm.