CABAC is the entropy coding method adopted in H.264/AVC main profile

and the combination of RDO and CABAC can represent an improvement in bit rate of around 20%.However

the computational complexity increases drastically as well.Parallel algorithms are efficient ways to speed up the encoder.However

because of the adaptive characteristic of CABAC

there are strict data-dependencies between macro-blocks encoding

which makes it hard to exploit the parallelism of encoder.In this paper

an efficient parallel algorithm for H.264/AVC encoder with CABAC entropy coding is proposed based on the Macro-Block Region Partition(MBRP)parallel method and CABAC bit-rate estimation technique:the H.264 encoder is partitioned into the mode decision part and the bit-stream producing part with relationship of producer and consumer;CABAC in the RDO mode decision is replaced with bit-rate estimation

which removes the data-dependencies brought by CABAC;in the mode decision part

the MBRP parallel algorithm is adopted;the bit-stream producing part is performed in a single processor

and forms task pipelining with mode decision part.Simulation results on 4-processor simulator show that the proposed parallel algorithm can achieve speedups above 4.7 while maintaining the similar R-D performance.