Experiments show that the method of equally allocating bitrate may cause unmatching between the activity of the sub-picture and its bitrate.An allocating method is proposed based on activity analysis.

• 实验表明，平均分配码率存在着子图的码率分配与其活动性不匹配的弊病，为此，提出了一种基于活动性分析的码率分配方法。