摘要
针对视频传输系统主要关注的两个因素:传输所用的总体带宽和终端最终的解码失真,提出带宽-失真(B-D)代价函数的概念,给出B-D关系定理及其证明.利用视频数据本身存在的时空相关的特点,进一步提出了基于最小化B-D代价的部分重传机制.实验结果及分析表明,相对于尽力而为ARQ机制,所提出的算法有如下几个特点:(1)在保持终端接收质量基本不变的前提下,能有效减少带宽(可达20%以上);(2)在低比特率情形下性能比高比特率下的性能要好,所以更适合于低比特应用;(3)对运动平缓和纹理平滑的视频序列更为有效.
There are two critical factors in error prone video transmission: the total usage of bandwidth and the distortion of reconstructed images at receiver side. Therefore, the concept of bandwidth-distortion(B-D) cost is proposed intuitively so as to evaluate a video transmission system more effectively. Further, B-D relationship is provided as a theorem, by which B-D cost function could be definitely made out. With these tools, a partial retransmission scheme based on minimal B-D cost is proposed based on the temporal and spatial correlation in video sequence. From the analytical analysis, it can be seen that B-D cost is more effective than bandwidth or distortion only when evaluating the performance of an error prone video transmission system, Besides, the proposed partial retransmission scheme can reduce the bandwidth usage effectively by the use of the temporal and spatial correlation in video sequence. Simulation results and discussions show that, compared to best effort ARQ scheme (BEARQ), the proposed scheme has the following features: (1) It can reduce the usage of bandwidth (maximally more than 20% on average) while keeping the quality of reconstructed images to be nearly unchanged; (2) It is preferable to be used in low bit rate since its B D performance is better in low bit rate than in high bit rate; (3) Similarly, it is preferable for the sequence in which motion and texture is relatively slow and smooth since in the case, its B-D performance is better.
出处
《计算机学报》
EI
CSCD
北大核心
2007年第2期212-224,共13页
Chinese Journal of Computers
基金
国家自然科学基金(60302028)资助
关键词
带宽-失真代价函数
部分重传
视频传输
B—D函数
bandwidth distortion cost
partial retransmission
video transmission
B-D relationship