AVS1-P2 introduces several prediction modes for inter coding. In order to achieve the best coding efficiency

the rate distortion optimization is exploited to choose the most suitable predicting mode

but it is very computationally expensive. In this paper

according to the characteristics of AVS1-P2 integer transform

we propose a new fast inter mode decision algorithm to improve the encoder speed based on two criterions

early termination based on all zero block detection and the prediction of inter-mode size using texture characteristic of macroblock. Compared with the reference code

simulation results show that this method will reduce the computing complexity of encoder and improve the encoding efficiency of AVS1-P2 software encoder while bit-rate and video quality almost remain unchanged.