介绍DRTD系统中无线列调语音业务的音频回放技术。DRTD系统有线通信基于SIP协议和R T P流进行音频传输,通过混音、加窗语音检测、缓存、格式转换、信令控制等处理流程,将音频流在无线空口上进行传输,并最终在移动终端上实现语音波形回放...介绍DRTD系统中无线列调语音业务的音频回放技术。DRTD系统有线通信基于SIP协议和R T P流进行音频传输,通过混音、加窗语音检测、缓存、格式转换、信令控制等处理流程,将音频流在无线空口上进行传输,并最终在移动终端上实现语音波形回放,从而桥接无线列调中的有线通信和无线通信,为DRTD系统的核心业务提供支撑。展开更多
实时传输协议(real-time transport protocol,RTP)用于视频数据流的实时传输和质量监测。针对可伸缩编码(scalable video coding,SVC)视频数据经过差错信道后出现质量增强层数据丢失的问题,根据RTP封装报头判断丢失的质量增强层位置,采...实时传输协议(real-time transport protocol,RTP)用于视频数据流的实时传输和质量监测。针对可伸缩编码(scalable video coding,SVC)视频数据经过差错信道后出现质量增强层数据丢失的问题,根据RTP封装报头判断丢失的质量增强层位置,采取丢弃或拷贝补偿方法实现差错隐藏。实验结果证明了差错隐藏算法的有效性和标准兼容性。展开更多
随着电视系统由传统的串行数字接口(Serial Digital Interface,SDI)架构逐渐向网际互连协议(Internet Protocol,IP)架构转变,网络时钟协议(Network Time Protocol,NTP)、精确时间协议(Precision Time Protocol,PTP)、实时传输协议(Real-...随着电视系统由传统的串行数字接口(Serial Digital Interface,SDI)架构逐渐向网际互连协议(Internet Protocol,IP)架构转变,网络时钟协议(Network Time Protocol,NTP)、精确时间协议(Precision Time Protocol,PTP)、实时传输协议(Real-time Transport Protocol,RTP)时间戳(Timestamp)、电影和电视工程师协会(The Society of Motion Picture and Television Engineers,SMPTE)ST 2059等信号取代了传统SDI架构中的黑场(Black Burst,BB)信号,成为IP化电视系统的设备同步、流同步信号。基于此,详细介绍PTP的同步原理、RTP数据包的重要数据格式、RTP时间戳在视音频流同步中的原理及SMPTE ST 2059的定义及相关应用。展开更多
可伸缩视频编码(Scalable Video Coding,SVC)一般采用实时传输协议(Real-time TransportProtocol,RTP)保证视频数据流的实时传输和质量监测。本文在分析SVC码流结构和RTP协议的基础上实现了H.264/SVC视频数据的RTP封装算法,提出了一种...可伸缩视频编码(Scalable Video Coding,SVC)一般采用实时传输协议(Real-time TransportProtocol,RTP)保证视频数据流的实时传输和质量监测。本文在分析SVC码流结构和RTP协议的基础上实现了H.264/SVC视频数据的RTP封装算法,提出了一种基本层与增强层分离的灵活封装机制模拟SVC在不同差错信道中的传输,通过在H.264/SVC模拟测试环境中的实验证明RTP封装机制的有效性,标准兼容性和可扩展性。展开更多
The scalable extension of H.264/AVC, known as scalable video coding or SVC, is currently the main focus of the Joint Video Team’s work. In its present working draft, the higher level syntax of SVC follows the design ...The scalable extension of H.264/AVC, known as scalable video coding or SVC, is currently the main focus of the Joint Video Team’s work. In its present working draft, the higher level syntax of SVC follows the design principles of H.264/AVC. Self-contained network abstraction layer units (NAL units) form natural entities for packetization. The SVC specification is by no means finalized yet, but nevertheless the work towards an optimized RTP payload format has already started. RFC 3984, the RTP payload specification for H.264/AVC has been taken as a starting point, but it became quickly clear that the scalable features of SVC require adaptation in at least the areas of capability/operation point signaling and documentation of the extended NAL unit header. This paper first gives an overview of the history of scalable video coding, and then reviews the video coding layer (VCL) and NAL of the latest SVC draft specification. Finally, it discusses different aspects of the draft SVC RTP payload format, in- cluding the design criteria, use cases, signaling and payload structure.展开更多
This paper chiefly introduces the model of Video Conferencing System, H.323 standard of ITU- T and RTP/RTCP protocol, and realizes a WAN- Oriented Video Conferencing System—VCSW (Video Conferencing System on WAN). In...This paper chiefly introduces the model of Video Conferencing System, H.323 standard of ITU- T and RTP/RTCP protocol, and realizes a WAN- Oriented Video Conferencing System—VCSW (Video Conferencing System on WAN). In VCSW, RTP/RTCP pro- tocol is used for transporting media data and video conference on WAN can be established, so VCSW has abroad application scope. This paper stresses analyzing RTP/RTCP protocol, realizes it and modifies some details of it according to our device condition: re- duces some fields of RTP and RTCP header, removes some information managed by RTP/RTCP. Consequently in testing of lab, good effect is achieved.展开更多
文摘介绍DRTD系统中无线列调语音业务的音频回放技术。DRTD系统有线通信基于SIP协议和R T P流进行音频传输,通过混音、加窗语音检测、缓存、格式转换、信令控制等处理流程,将音频流在无线空口上进行传输,并最终在移动终端上实现语音波形回放,从而桥接无线列调中的有线通信和无线通信,为DRTD系统的核心业务提供支撑。
文摘实时传输协议(real-time transport protocol,RTP)用于视频数据流的实时传输和质量监测。针对可伸缩编码(scalable video coding,SVC)视频数据经过差错信道后出现质量增强层数据丢失的问题,根据RTP封装报头判断丢失的质量增强层位置,采取丢弃或拷贝补偿方法实现差错隐藏。实验结果证明了差错隐藏算法的有效性和标准兼容性。
文摘随着电视系统由传统的串行数字接口(Serial Digital Interface,SDI)架构逐渐向网际互连协议(Internet Protocol,IP)架构转变,网络时钟协议(Network Time Protocol,NTP)、精确时间协议(Precision Time Protocol,PTP)、实时传输协议(Real-time Transport Protocol,RTP)时间戳(Timestamp)、电影和电视工程师协会(The Society of Motion Picture and Television Engineers,SMPTE)ST 2059等信号取代了传统SDI架构中的黑场(Black Burst,BB)信号,成为IP化电视系统的设备同步、流同步信号。基于此,详细介绍PTP的同步原理、RTP数据包的重要数据格式、RTP时间戳在视音频流同步中的原理及SMPTE ST 2059的定义及相关应用。
文摘可伸缩视频编码(Scalable Video Coding,SVC)一般采用实时传输协议(Real-time TransportProtocol,RTP)保证视频数据流的实时传输和质量监测。本文在分析SVC码流结构和RTP协议的基础上实现了H.264/SVC视频数据的RTP封装算法,提出了一种基本层与增强层分离的灵活封装机制模拟SVC在不同差错信道中的传输,通过在H.264/SVC模拟测试环境中的实验证明RTP封装机制的有效性,标准兼容性和可扩展性。
文摘The scalable extension of H.264/AVC, known as scalable video coding or SVC, is currently the main focus of the Joint Video Team’s work. In its present working draft, the higher level syntax of SVC follows the design principles of H.264/AVC. Self-contained network abstraction layer units (NAL units) form natural entities for packetization. The SVC specification is by no means finalized yet, but nevertheless the work towards an optimized RTP payload format has already started. RFC 3984, the RTP payload specification for H.264/AVC has been taken as a starting point, but it became quickly clear that the scalable features of SVC require adaptation in at least the areas of capability/operation point signaling and documentation of the extended NAL unit header. This paper first gives an overview of the history of scalable video coding, and then reviews the video coding layer (VCL) and NAL of the latest SVC draft specification. Finally, it discusses different aspects of the draft SVC RTP payload format, in- cluding the design criteria, use cases, signaling and payload structure.
基金Approval No. of the National Natural ScienceFund: 60573182
文摘This paper chiefly introduces the model of Video Conferencing System, H.323 standard of ITU- T and RTP/RTCP protocol, and realizes a WAN- Oriented Video Conferencing System—VCSW (Video Conferencing System on WAN). In VCSW, RTP/RTCP pro- tocol is used for transporting media data and video conference on WAN can be established, so VCSW has abroad application scope. This paper stresses analyzing RTP/RTCP protocol, realizes it and modifies some details of it according to our device condition: re- duces some fields of RTP and RTCP header, removes some information managed by RTP/RTCP. Consequently in testing of lab, good effect is achieved.
