Aiming at the problem quasi-cyclic Low-Density Parity-Check(LDPC) code has an efficient encoding algorithm,the degree distribution of the code usually can not satisfy the optimal degree distribution.This paper disposes the distribution of unit cyclic shift matrix in check matrix,improves the method for constructing check matrix.Simulation results show that improved construction method has efficient encoding algorithm,makes the code with approximate optimal degree distribution,and the code has better performance under the condition of the same code length.

Aiming at the time-consuming problem of existing motion estimation in H.264/AVC encoder,this paper proposes a new fast motion estimation algorithm based on multi-template.It divides the current block as a quasi-stationary,slow motion,or fast motion block.According to the different motion block types,different search templates and strategies are employed.Experimental results demonstrate that this algorithm raises the encoding speed with about the same image quality.