针对视频帧中可能出现的大量场景切换,提出一种基于非连接点的场景切换检测算法,提高编码性能,该场景检测算法复杂度低,在运动估计的同时,完成视频场景切换检测。场景切换将导致GOP(group of pictures)长度的变化,并可能出现GOP长度太短的情况。提出改进的自适应GOP时域滤波技术,避免由于GOP太短引起的编码性能下降。针对视频场景切换检测分割出的不同长度的GOP,提出一种基于率失真模型的帧间码率控制算法,利用视频的失真与码率及视频帧复杂度的关系,对帧间码率分配进行优化,提高重构视频帧的总质量。实验结果表明,基于场景检测的自适应帧间码率控制算法能够获得较好的编码性能。

A scene change detection algorithm based on non-connected points is proposed to solve the problems of scene changes existed in videos, which can improve the coding performance. The complexity of the proposed algorithm is low and scene change detection is processing at the same time of the motion estimation. Scene changes can cause different GOP(group of pictures)sizes, which can result in GOP with a short size. We propose an improved adaptive GOP motion compensation temporal filtering, which can effectively avoid the short GOP problem resulting in a decline of coding perfor- mance. For each GOP generated by scene change detection, a frame-layer rate control algorithm based on a rate distortion model is proposed, using the relation between the distortion and the rate and the complexity of the video frame to optimize the rate distribution, aiming at improving the quality of the reconstructed video. The experimental results show that the proposed algorithm can achieve better performance than other rate control algorithms.