一种新的H.264自适应帧层码率控制算法

A Novel Adaptive Rate Control Algorithm for H.264 Frame Layer

现存的H.264帧层码率控制算法没有考虑到视频序列编码复杂度和可用信道带宽之间的关系.针对这一问题,提出了一种新的H.264帧层码率控制算法.首先将视频序列划分成不同的场景;然后使用信道带宽充裕度来描述各场景的编码复杂度与可用信道带宽之间的关系;最后根据信道带宽充裕度和基于宏块级亮度直方图差异的相对复杂度对帧层目标比特和量化参数进行调整.仿真结果表明,和JVT-G012相比,在不同信道带宽充裕度下,文中提出的算法能够在压缩后图像质量、可用信道带宽和编码器缓冲区占用度之间做出更好的平衡.

As the existing rate control algorithms for H. 264 frame layer do not consider the relationship between the encoding complexity of video sequence and the available channel bandwidth, a novel rate control algorithm is proposed. In this algorithm, each video sequence is divided into several scenes, and the channel bandwidth sufficiency is introduced to describe the relationship between the encoding complexity of each scene and the available channel bandwidth. Moreover, the target bit and the quantization parameter are adjusted according to the channel bandwidth sufficiency and the relative encoding complexity measurement based on block histogram. Simulated results show that, as compared with JVT-G012, the proposed algorithm can achieve better trade-off among compressed video quality, available channel bandwidth and encoder buffer fullness under different channel bandwidth sufficiencies.