基于复杂度分析的HEVC帧内码率控制算法

INTRA RATE CONTROL ALGORITHM BASED ON COMPLEXITY ANALYSIS FOR HEVC

随着高清、超高清视频应用的快速发展,码率控制的作用越来越重要。在高效视频编码HEVC(High Efficient Video Coding)中,码率控制算法在码率输出的精度和效率上都取得不错的效果,但是算法并没有考虑到实际视频编码内容的复杂度。针对此问题,提出一种基于复杂度的HEVC帧内码率控制算法。首先利用梯度来表征复杂度,根据复杂度来合理分配码率,然后根据产生的实际比特和预分配比特自适应地更新平滑窗口,最后再结合基本单元层的码率控制算法及时调节码率,从而使输出码率尽可能与目标码率相等。实验结果表明,所提出的方法能够使输出码率更加接近目标码率,并且可以进一步提高视频质量。

With the rapid development of high-fidelity video,rate control plays a more and more important role in its applications. Rate control algorithm has achieved great performance on the rate of the output precision and coding efficiency in HEVC. However,rate control algorithm does not put the complexity of the actual content of video coding into consideration. Aiming at this problem,a rate control algorithm based on complexity analysis is proposed. First,the bit rate of frame layer is allocated according to the complexity which is represented by gradient. Then,the actual bits and pre-allocated bits are utilized to adaptively update the smooth window. Finally,combining with basic unit layer rate control algorithm,the bit rate is adjusted to make the output bit rate approaches the target bit rate. Experiment result shows that the method can not only maintain the output bit rate more accurate,but also improve the coding quality.