摘要
视频帧类型决策是影响视频编码效率的关键因素之一。为提升x265视频编码器的编码性能,该文提出基于局部亮度直方图的自适应视频帧类型决策算法。首先,在64×64大小的编码树单元(CTU)级别上统计各帧局部亮度直方图,用帧间局部亮度直方图差异表征帧间场景变换程度;其次,引入帧内编码帧(I帧)检测窗,在检测窗内通过比较帧间场景变换程度自适应确定I帧;最后,根据帧间场景变换程度与迷你图像组(MiniGOP)大小之间的相关性确定MiniGOP大小,从而自适应确定普通P和B帧(GPB帧)及双向预测编码帧(B帧)。实验结果表明,与x265标准中的相关算法相比,所提算法能够有效降低x265的编码复杂度,可在减少近5%编码时间的前提下,实现视频I帧、GPB帧和B帧的高效自适应决策。
The video frame type decision is one of the key factors affecting the efficiency of video coding. This paper proposes an adaptive video frame type decision algorithm based on local luminance histogram to improve the x265 encoding performance. Firstly, the local luminance histograms of frames are calculated at the level of64×64 Coding Tree Unit(CTU), and the difference of local luminance histogram between frames is used to represent the degree of scene variation between frames. Secondly, Intra-coded picture(I-frame) detection window is introduced. I-frame is determined by comparing the degree of scene variation between frames.Finally, the Mini Group Of Picture(MiniGOP) size is determined according to the correlation between the degree of scene variation and MiniGOP size, so as to determine adaptively Generalized P and B picture(GPBframe) and Bidirectionally predicted picture(B-frame). Experimental results show that compared with the relevant algorithms in x265, the proposed algorithm can effectively reduce the coding complexity of x265, and decide I/GPB/B-frame efficiently and adaptively with nearly 5% less coding time.
作者
刘鹏宇
张悦
贾克斌
段堃
刘畅
孙萱
崔腾鹤
LIU Pengyu;ZHANG Yue;JIA Kebin;DUAN Kun;LIU Chang;SUN Xuan;CUI Tenghe(The Information Department,Beijing University of Technology,Beijing 100124,China;Advanced Information Network Beijing Laboratory,Beijing 100124,China;Computational Intelligence and Intelligent Systems Beijing Key Laboratory,Beijing 100124,China)
出处
《电子与信息学报》
EI
CSCD
北大核心
2023年第1期300-307,共8页
Journal of Electronics & Information Technology
基金
国家重点研发计划(2018YFF01010100)
北京自然科学基金(4212001)
青海省重点研发与转化计划(2022-QY-205)。
