Cheng, YunWang, ZhiyingDai, KuiGuo, JianjunN. Correia and J. Jorge and T. Chambel and Z. Pan2014-01-262014-01-2620043-905673-17-71812-7118https://doi.org/10.2312/EGMM/MM04/077-086H.264/AVC is a new international standard for video coding which has great advantage of coding efficiency com-pared with other standards. It can save about 50% bit-rate compared with that of the successful prior coding stan-dards under the same reconstructed picture quality. But the high coding efficiency is acquired by heavily computa-tion. In this paper, the coding mode and algorithm for mode decision are introduced firstly, then transform and quantization are analyzed and experiments on inter-frame coding with or without intra modes are performed. The experiment results illustrate that the encoding method without intra modes in inter-frame coding will decrease the encoding time from 76.03% to 50.09% compared with that of the standard encoding method, while the PSNR-Y will change from -0.45dB to +0.20dB (most cases are ±0.10dB) at the same bit-rates.