精确的码率控制是进行高效视频编码与传输的关键。针对现有码率控制技术的不足，提出了在视频编码中采用两个率失真模型进行码率预测的思想以提高码率控制的精度。对H.264的G012码率控制框架进行改进，给出一种基于双模预测的自适应码率控制方法。实验仿真结果显示，与传统的单模码率控制方法相比，基于双模预测的码率控制算法能保证在不影响编码质量的前提下有效地提高码率控制的精度。

Accurate rate control is a key technology for efficient video coding and transmission. In view of the drawbacks of existing rate control algorithms, a novel idea that implements rate control by using two rate-distortion models is introduced to enhance the rate-control precision. And a new double model based rate-control algorithm is proposed by adapting the G012 framework of H.264 standard. Experiments are conducted and the results reveal that, compared with the original G012 algorithm, the proposed algorithm can efficiently enhance the rate control precision without deteriorating the reconstructed video quality