Parallel Pipeline Hardware Design of Intra Rate-Distortion Optimization Prediction Mode in HEVC

In recent years, the resolution and frame rate of video have been continuously improved to meet people’ s increasing demand for video data. However, the compression encoding speed of real-time video sequence is often restricted by frame rate and resolution. The higher the frame rate and resolution are, the longer the encoding time will be. In order to achieve real-time compression encode for video sequences with higher resolution and frame rate, this paper designed a new parallel pipeline hardware architecture of intra rate-distortion optimization prediction mode, which supports intra prediction coding of up to 64×64 coding tree unit. Firstly, a parallel scheme with 9-way prediction mode was designed. Secondly, a pipeline hardware architecture was implemented based on a 4×4 block as the basic processing unit in a Z-shaped scanning order, and the prediction data of 32×32 prediction units were reused to replace the prediction data of 64×64 prediction units so as to reduce the amount of calculation. Lastly, a new Hadamard transform circuit was proposed based on this pipelined architecture for efficient pipelined processing. The experimental results show that: on the Altera Arria 10 series field programmable gate array, the 9-way mode parallel architecture only occupies 75 kb look up table and 55 kb register resources, the main frequency can reach 207 MHz, and it only takes 4096 clocks cycles to complete a 64×64 coding tree unit prediction and can support real-time encoding of 1080 P resolution 99 f/s full I-frame at most. Compared with the existing design scheme, the scheme designed in this paper can realize higher frame rate 1080 P real time video encoding with smaller circuit area.