共查询到18条相似文献，搜索用时 187 毫秒
1.
随着流媒体技术的发展,实时传输协议RTP被广泛用于各种多媒体传榆系统中,为实时应用提供端到端的传输。可伸缩视频编码（SVC）因其时域、空间和质量的可分级,能够为用户提供可分级性更强的视频流,满足不同终端设备用户的需求。本文针对SVC视频流应用于NS2网络传输仿真而设计了一套可伸缩视频编码的RTP卦装方案,并将其应用于NS2仿真环境,实现了真实视频流的实时调度与传输。实验结果验证了该RTP卦装方案的正确性和有效性。 相似文献
2.
《实验室研究与探索》2018,(12)
基于视频监控应用领域应用广泛,对视频监控的实时性已成为检验安防系统的重要标准,为此设计以TE6410开发板为硬件平台为核心基于Linux系统实现H. 264软件编码的实时监控系统。平台采用cmos摄像头基于V4L2接口采集视频,采用X264软件编码压缩,实现了视频的高度压缩比;基于RTP协议打包封装H. 264视频流经网络传输到VLC播放器,显示监控画面。经实验测试结果证明,系统监控图像清晰,播放流畅达到了实时监控的效果。 相似文献
3.
陈颖 《福建信息技术教育》2007,(4)
以H.264/AVC为代表的新一代视频编码技术,采用分层模式,不仅通过视频编码层改善了编码效率,而且通过网络提取层提高了网络传输适应性,并且在封装规范中体现了流媒体实时传输特性。 相似文献
4.
针对网络视频通信中对视频图像清晰度以及减少视频过多占用网络资源的双重要求,设计了一种基于OMAP3530视频处理芯片、H.264压缩技术、嵌入式Linux操作系统、RTP/RTCP网络传输协议的数字视频服务器,给出了系统的总体结构与软硬件模块,重点阐述了视频采集及处理的过程。客户端通过接收、解码及显示监控前端传送的H.264视频流,实时显示监控场景。实验表明,系统实时监测性能良好,图像解码清晰、稳定,具有很强的实用性和广阔的发展前景。 相似文献
5.
蔡高 《湖北广播电视大学学报》2003,20(1):59-66
桌面可视电话终端的软件实现应该包括视频和语音采集、视频和语音编解码、控制、复用、同步、实时传输等。本文的可视电话终端的视频模块采用经过改进的H.263视频编解码标准,语音模块采用G.723.1编解码,H.225.0协议实现呼叫及分组复用,H.245实现信道控制,RTP/RTCP实现实时传输。 相似文献
6.
随着网络的迅速发展，传统的TCP／IP协议在流媒体（音频流、视频流）的实时传输上受到了很大的挑战。因为该协议在网络上提供的是非实时的数据传输服务，并且其重传机制与拥塞控制机制也给实时传输带来较大困难。为了解决该问题提出了支持多媒体实时传输的协议RTP，主要论述了RTP协议及RTCP协议的基本原理，并以此为基础实现了在视频传输上的一个应用，提出了相应的拥塞控制策略，在百兆局域网上该应用获得了很好的效果。 相似文献
7.
曾欣 《深圳信息职业技术学院学报》2005,3(1):30-34
基于对网络摄像机这种特定应用的需求分析，指出了视频信号网络传输的特点在于实时性要求高，而可靠性要求相对较低，因此RTP（实时传输协议）和RTCP（实时传输控制协议）协议比TCP协议更适合应用于网络视频传输。同时针对嵌入式平台的特点，提出了硬件实现方案和软件处理流程，并且详细分析和解决了RTP和RTCP协议在实现过程中的关键问题。试验结果证明网络摄像机系统在实时性和可靠性上都达到了令人满意的结果。 相似文献
8.
H.264/SVC实现了对基本层的码率控制,但没有考虑到视频序列中场景切换对码率控制的影响。研究者们提出了多种场景切换算法来解决视频序列场景切换问题,但这些算法在计算复杂度、精度和实时检测等方面存在不足。结合H.264/SVC的分层B帧预测金子塔编码结构,提出了一种基于图像复杂度的场景切换实时检测算法RDSC_IC(Real time Detection algorithm for Scene Change base on Image Complexity)。该算法通过对相邻和多个编码单元的关键帧图像复杂度绝对差值和相应比值的计算,确定编码单元间的场景切换的有无和类型,实验结果表明RDSC_IC在实时性和精度方面检测效果好。 相似文献
9.
曾欣 《深圳信息职业技术学院学报》2005,(2)
基于对网络摄像机这种特定应用的需求分析,指出了视频信号网络传输的特点在于实时性要求高,而可靠性要求相对较低,因此RTP(实时传输协议)和RTCP(实时传输控制协议)协议比TCP协议更适合应用于网络视频传输.同时针对嵌入式平台的特点,提出了硬件实现方案和软件处理流程,并且详细分析和解决了RTP和RTCP协议在实现过程中的关键问题.试验结果证明网络摄像机系统在实时性和可靠性上都达到了令人满意的结果. 相似文献
10.
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, including the design criteria, use cases, signaling and payload structure. 相似文献
11.
In this work, we present an evaluation of the performance and error robustness of RTP-based broadcast streaming of high-quality high-definition (HD) H.264/AVC video. Using a fully controlled IP test bed (Hillestad et al., 2005), we broadcast high-definition video over RTP/UDP, and use an IP network emulator to introduce a varying amount of randomly distributed packet loss. A high-performance network interface monitoring card is used to capture the video packets into a trace file. Purpose-built software parses the trace file, analyzes the RTP stream and assembles the correctly received NAL units into an H.264/AVC Annex B byte stream file, which is subsequently decoded by JVT JM 10.1 reference software. The proposed measurement setup is a novel, practical and intuitive approach to perform error resilience testing of real-world H.264/AVC broadcast applications. Through a series of experiments, we evaluate some of the error resilience features of the H.264/AVC standard, and see how they perform at packet loss rates from 0.01 % to 5%. The results confirmed that an appropriate slice partitioning scheme is essential to have a graceful degradation in received quality in the case of packet loss. While flexible macroblock ordering reduces the compression efficiency about 1 dB for our test material, reconstructed video quality is improved for loss rates above 0.25%. 相似文献
12.
In this work, we present an evaluation of the performance and error robustness of RTP-based broadcast streaming of high-quality high-definition (HD) H.264/AVC video. Using a fully controlled IP test bed (Hillestad et al., 2005), we broadcast high-definition video over RTP/UDP, and use an IP network emulator to introduce a varying amount of randomly distributed packet loss. A high-performance network interface monitoring card is used to capture the video packets into a trace file. Purpose-built software parses the trace file, analyzes the RTP stream and assembles the correctly received NAL units into an H.264/AVC Annex B byte stream file, which is subsequently decoded by JVT JM 10.1 reference software. The proposed measurement setup is a novel, practical and intuitive approach to perform error resilience testing of real-world H.264/AVC broadcast applications. Through a series of experiments, we evaluate some of the error resilience features of the H.264/AVC standard, and see how they perform at packet loss rates from 0.01% to 5%. The results confirmed that an appropriate slice partitioning scheme is essential to have a graceful degradation in received quality in the case of packet loss. While flexible macroblock ordering reduces the compression efficiency about 1 dB for our test material, reconstructed video quality is improved for loss rates above 0.25%. 相似文献
13.
Frame loss error concealment for SVC 总被引：2，自引：0，他引：2
INTRODUCTION Real-time transmission of video data in network environments, such as wireless and Internet, is a challenging task, as it requires coding efficiency, network friendliness and error robustness. Scalability is a possible solution for network adaptive applica- tions. The Scalable Extension of H.264/AVC (SVC) (JVT of ISO/IEC MPEG & ITU-T VCEG, 2005b) aims at achieving both high compression performance and adaptivity for video delivery over heterogeneous networks. SVC… 相似文献
14.
INTRODUCTION Low latency video transmission is very de manding in terms of the performance of all layers i the protocol stack. Over the last decade, research ha focused on enhancements of each individual laye without considering cross-layer interactions. Adapt ing video coding to the channel/network condition and technologies (and vice versa) (Girod et al., 2002 via the cross-layer exchange of information has onl recently been investigated. van der Schaar et al.(200 developed a cross-laye… 相似文献
15.
秦秀贵 《山东教育学院学报》2008,23(5):95-97
H.264/MPEG-4 AVC定义了9种4×4亮度块的预测模式,在参考模型JM中所采用的RDO计算复杂度较高。本文提出了一种基于各向同性Sobel算子的H.264的快速帧内编码模式选择算法,降低预测的复杂度,提高编码速度。测试表明,此算法能够使编码速度提高将近75%。 相似文献
16.
INTRODUCTION In typical video transmission systems, a video signal is compressed, and the resulting bit stream is transmitted over an error-prone channel. The errors may consist of symbol errors caused by fading, as observed for wireless channels, or packet erasures caused by congestion, as observed in the Internet. If a received video packet contains errors, then the portion of the video signal contained in the packet is lost and must be concealed. Error concealment schemes alone cannot … 相似文献
17.
网络视频监控系统研究 总被引：2，自引：0，他引：2
视频监控系统是安全防范系统的组成部分，它是 一种防范能力较强的综合系统。视频监控系统在公 安、金融证券、银行、商店、宾馆、智能大厦以及重要部 门、社区的安全方面能起到重要的作用。目前，广泛应 用的监控系统采用模拟技术。近年来，随着计算机、 网络以及图像处理、传 相似文献