Deadline-aware network coding for video on demand service over P2P networks

INTRODUCTION With the widespread deployment of broadband access, Video-on-Demand (VoD) streaming on the Internet has received increasing attention recently. In VoD service, video streams are delivered to asyn- chronous users with low delay and VCR-like opera- tion support (e.g., pause, fast-forward, and rewind). However, streaming to a large population of clients is very challenging due to the limited server capacity and little deployment of IP multicast in today’s Internet (Quinn a…     

Video over IP using standard-compatible multiple description coding: an IETF proposal

INTRODUCTION Communication networks are growing quickly. Throughput, delays and losses become unpredictable because of heterogeneity and congestion. This results in lack of quality of service. Today’s solution is based on standard video codecs (as MPEG-2) that do not allow scalability and yield low quality at low bit-rates, complex forward error correction (FEC) codes that are not easily used with time-varying channels and must be set to face the worst case, and automatic repeat re- q…     

Hybrid ants-like search algorithms for P2P media streaming distribution in ad hoc networks

Media streaming delivery in wireless ad hoc networks is challenging due to the stringent resource restrictions,po-tential high loss rate and the decentralized architecture. To support long and high-quality streams,one viable approach is that a media stream is partitioned into segments,and then the segments are replicated in a network and served in a peer-to-peer(P2P) fashion. However,the searching strategy for segments is one key problem with the approach. This paper proposes a hybrid ants-like search algorithm(HASA) for P2P media streaming distribution in ad hoc networks. It takes the advantages of random walks and ants-like algorithms for searching in unstructured P2P networks,such as low transmitting latency,less jitter times,and low unnecessary traffic. We quantify the performance of our scheme in terms of response time,jitter times,and network messages for media streaming distribution. Simulation results showed that it can effectively improve the search efficiency for P2P media streaming distribution in ad hoc networks.     

Rate-distortion optimized bitstream switching for peer-to-peer live streaming

Peer-to-peer （P2P） technology provides a cost-effective and scalable way to distribute video data. However, high heterogeneity of the P2P network, which rises not only from heterogeneous link capacity between peers but also from dynamic variation of available bandwidth, brings forward great challenge to video streaming. To attack this problem, an adaptive scheme based on rate-distortion optimization （RDO） is proposed in this paper. While low complexity RDO based frame dropping is exploited to shape bitrate into available bandwidth in peers, the streamed bitstream is dynamically switched among multiple available versions in an RDO way by the streaming server. Simulation results show that the proposed scheme based on RDO achieves great gain in overall perceived quality over simple heuristic schemes.     

基于P2P的校园网流媒体平台的设计与实现

传统流媒体平台对服务器性能,网络带宽等条件要求较高,对校园网的视频应用服务有一定的局限性。为解决此问题,设计了一种基于P2P架构的流媒体视频教学平台,将流媒体技术的实时性和P2P网络的分布性完美地结合起来,实现了视频直播和点播功能。     

基于JMF软件的音视频辅导平台的开发

结合我国目前网络带宽的特点和教学的实际需求,应用JMF软件和流媒体相关技术,采用P2P+C/S模式,开发了1个多人音视频辅导平台,解决了音视频网络传输时的带宽资源占用,音视频同步控制,用户及流媒体管理等关键问题,使师生可以进行在线音视频同步交流和讨论,提高了学生学习的兴趣和质量,满足了教学的实际需求。     

Streaming and congestion control using scalable video coding based on H.264/AVC

INTRODUCTION Streaming of multimedia data over the Internet has rapidly increased in recent years. All commercial applications and most research in video streaming use conventional hybrid video coding. To adapt the data transmission rate on the server to the varying bandwidth caused by congestion in the Internet or to different available bandwidths of different clients, the simulcast solution is widely applied (Balk et al., 2003; Feamster et al., 2001; Schierl and Wiegand, 2004). A larg…     

Multipoint videoconferencing with scalable video coding

INTRODUCTION Modern videoconferencing systems allow two o more participants to communicate with each other in real-time using both audio and video. Conventionally when more than two participants are present, a sta configuration is generally employed, wherein a Mul tipoint Conferencing Unit (MCU), or bridge, is util ized to connect to all participants and coordinat communications between them. The general archi tecture is shown in Fig.1. Fig.1 Multipoint videoconferencing system Network…     

Multiple description scalable video coding based on 3D lifted wavelet transform

INTRODUCTION With the expansion of multimedia applications, video transmission is becoming an important issue in the research area of communication. It is very im- portant to compress a large amount of video data effectively, which has already attracted considerable attention recently. To make source coders both er- ror-resilient and network-adaptive are two main challenges facing the video compression techniques. It is necessary to make the bitstreams temporal, spa- tial and SNR scalabl…     

High throughput bandwidth optimized VLSI design for motion compensation in AVS HDTV decoder

In this paper we present a motion compensation （MC） design for the newest Audio Video coding Standard （AVS） of China. Because of compression-efficient techniques of variable block size （VBS） and sub-pixel interpolation, intensive pixel calculation and huge memory access are required. We propose a parallel serial filtering mixed luma interpolation data flow and a three-stage multiplication free chroma interpolation scheme. Compared to the conventional designs, the integrated architecture supports about 2.7 times filtering throughput. The proposed MC design utilizes Vertical Z processing order for reference data re-use and saves up to 30% memory bandwidth. The whole design requires 44.3k gates when synthesized at 108 MHz clock frequency using 0.18-μm CMOS technology and can support up to 1920×1088@30 fps AVS HDTV video decoding.     

3G网络基础上移动视频监控系统平台的设计

该文对在3G网络下的图象压缩技术和视频编码技术进行了详细的阐述和分析,并设计出一套基于3G网络的移动视频监控系统平台模型,将3G移动网络争固网视频监控结合起来,实现两者优势互补,此平台模型能够弥补传统移动网络和固网的不足,对移动视频监控系统的设计具有一定的指导意义．     

基于P2P流媒体技术的远程教育系统的设计

随着网络及流媒体技术的发展,越来越多的远程教育系统开始采用流媒体作为主要的网络教学方式.它可以提高网络课堂的质量,增强网络课堂的交互性.而基于P2P的流媒体可以充分发挥众多客户机的作用,有效利用客户机闲置的计算和存储资源,使客户机完成部分服务器的功能,降低服务器的负载和对网络带宽的占用率.因此,基于P2P的流媒体技术在远程教育中的应用已成为一种必然的趋势.在传统流媒体技术的基础上提出混合式结构的P2P流媒体模式,以进一步优化远程教育系统.     

校园网的网络电视台规划与构建——以漳州某高校网络电视台为例

论述在漳州一高校校园网络,基于P2P流媒体技术的多频道网络电视台系统规划和构建,通过有效利用现有设备,整合网络、带宽、和计算机终端的基础,实现数千人并发的网络视频直播等多媒体综合应用,并采取简捷安全的管理方式和全方位的服务保障使得师生能够通过每台计算机终端流畅地收看本校的多频道网络电视,浏览和共享多媒体信息资源,满足校内不同访问人群的教学、工作、新闻、娱乐等需要,实现教学应用的多元化.     

基于JND和AR模型的感知视频编码方法(英文)

为了达到减少比特数同时保持画面质量的目的,提出了一种基于最小可视失真(JND)和自回归(AR)模型的感知视频编码方法.首先,设计了基于JND的纹理分割算法,建立了空时JND模型,以MB为基本单元,通过计算其JND能量并与阈值做比较,用以分割出视频序列中的纹理区域.然后,开发了AR模型来合成纹理区,在使用最小二乘法计算出AR模型的参数后,用相邻的前后参考帧对应像素的线性插值来生成重构像素.最后,为了检验所提方法的效果,将其与H.264/AVC视频编码系统做比较,用不同的视频序列实验来验证所提方法的有效性.实验结果显示,对于具有不同纹理特点的实验序列,所提方法可以在保持感知质量的同时将比特率减少15%～58%.     

Distributed media cooperation for enhanced video communication

INTRODUCTION According to yearly statistics the demand for multimedia traffic over computer networks is con- stantly on the increase (Nielsen//NetRatings, http:// www.nielsen-netratings.com/). Therefore, it is inevi- table that situations where different media streams will need to share communication resources will be- come commonplace. In such cases, it would be of interest to optimize the overall performance of the network. In other words, resources should be allo- cated across the com…     

P2P网络内容分发中心化的研究与实现

P2P作为一种与服务器/客户端对立的网络架构,其应用近些年来在互联网中发展十分迅速,新的P2P应用更是层出不穷.分析P2P网络内容分发中心化时流媒体服务器之间的数据传输,指出它们的优缺点,结合CDN和P2P关键技术在网络中的应用,提出了轻量级的P2P传输系统,对网络流量、资源分块和分段大小的控制,提高资源查找的效率,从而简化P2P资源的查找实现     

基于分块DCT的图像多描述编码研究

多描述编码(MDC)能有效提高数据在不可靠网络传输中的接收质量。结合JPEG编码原理,根据分块DCT系数的不同划分提出了两种图像MDC方法。该两种方法具有不同的应用特点,无论是单个描述还是两个描述的重构图均取得令人满意的效果。     

An Adaptive Quantization Algorithm for MPEG-2 Video Coding

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Joint routing and rate allocation for multiple video streams in ad-hoc wireless networks

INTRODUCTION Ad-hoc networks are attractive owing to their self-organizing nature and absence of a fixed infra- structure. They are particularly suited for communi- cation in disaster-affected areas, coordinating military operations, and sensing environmental conditions With the growing availability of supporting hardware and decreasing equipment cost, ad-hoc networking based applications are proliferating. Meshes of wire- less nodes are being deployed in cities and housing communities to…     

H．264预测编码关键技术的研究分析

H．264是目前最新的视频编码标准，相对于以前的ITU—T视频编码标准和mpeg序列标准具有更高的压缩效率．编码效率的提高主要归根于精确的帧间预测编码，其中包括多种块模式．多参考帧运动估计和分数像素精度3种新技术的采用，对这些帧间预测编码技术进行研究和分析．主要是分析这些技术与H．264基本配置之间的比较。