摘要
根据H.264视频流编码格式与视频传输实时性,提出一种基于传输控制协议(TCP)的双缓冲与双线程视频实时传输控制方法.考虑到实际情况下视频码率调整不能完全与网络带宽变化相同,重点阐述了处理视频传输过程中视频丢帧、视频码率上调与下调的三个主要控制策略:为了避免传输过程中视频"碎帧"出现,控制方法中设置一个帧地址数组实现视频数据按帧传输与丢弃;为了确保视频码率调整的正确性,控制方法采用时间为参数的线性加权累加方法来判断视频数据积累的变化趋势.给出了控制方法的具体步骤与测试情况,并与传统方法进行了比较.比较与测试结果表明:该控制方法能保证视频码率随网络带宽波动或在可变码率下随视频场景变化而自适应调整,可有效地应用于动态带宽网络环境下的实时视频监视.
A real-time video transmission control method using double buffers and double operation threads based on transmission control protocol （TCP） is proposed according to the characteristics of H. 264 video stream encoding and real-time video stream transmission. Considering the video bit rate adjustment can not be same completely with network bandwidth variation in actual fact, three key control strategies, which are video frames discarding, video bitrate increase and decrease, were elaborated. In these control strategies, a frame address array is set up to achieve video data transmission and discarding according to the frame unit in the control method in order to avoid the emergence of ＂broken frame＂. At the same time, a linear weighted summation method is used to judge the change trend of the accumulated video data in the control method in order to ensure the correctness of the video bitrate adjustment. The specific procedures, test cases and comparison with exiting traditional methods were given at last. The test result and the comparison show that the proposed control method can ensure the video bitrate adaptive adjustment according to the network bandwidth fluctuation or video scene change under variable bit control, utilize network variable bandwidth in the greatest extent for transmitting video to receiver by real-time and play back smoothly in receiver accordingly, and can be applied effectively to real-time video surveillance under the circumstances of variable bandwidth network.
出处
《浙江大学学报（工学版）》
EI
CAS
CSCD
北大核心
2012年第12期2146-2154,共9页
Journal of Zhejiang University：Engineering Science
基金
浙江省省级重点科技创新团队项目(2012R10009-06)
浙江省公益性技术应用研究计划资助项目(2011C21035)
浙江大学工业控制技术国家重点实验室开放课题基金资助项目(ICT1004)
关键词
H
264
实时传输
视频码率
网络带宽
视频丢帧
H. 264
real-time transmission
video bitrate
network bandwidth
discard video frames
