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An Adaptive Motion-Based Unequal Error Protection Approach for Real-Time Video Transport Over Wireless IP Networks 总被引:1,自引:0,他引:1
《Multimedia, IEEE Transactions on》2006,8(5):1033-1044
In this work, we consider the delivery of digital video over future 3G wireless IP networks and we propose a low-complexity adaptive motion-based unequal error protection (UEP) video coding and transmission system which efficiently combines three existing error-resilience techniques by exploiting knowledge of the source material as well as the channel operating conditions. Given this information, the proposed system can adaptively adjust the operating parameters of the video source encoder and the forward error correction (FEC) channel encoder to maximize the delivered video quality based upon both application-layer video motion estimates and link-layer channel estimates. We demonstrate the efficacy of this approach using the ITU-T H.264 video source coder. The results indicate that a significant performance improvement can be achieved with enhanced resilience to inaccurate channel feedback information and with substantially reduced computational complexity compared to competing approaches. 相似文献
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The motion-compensated temporal filtering (MCTF)-based scalable video coding (SVC) provides a full scalability including spatial, temporal and signal-to-noise ratio (SNR) scalability with fine granularity, each of which may result in different visual effect. This paper addresses a novel approach of two-dimensional unequal error protection (2D UEP) for the scalable video with a combined temporal and quality (SNR) scalability over packet-erasure channel. The bit-stream is divided into scalable subbitstreams based on the structure of MCTF. Each subbitstream is further divided into several quality layers. Unequal quantities of bits are allocated to protect different layers to obtain acceptable quality video with smooth degradation under different transmission error conditions. Experimental results are presented to show the advantage of the proposed 2D UEP scheme over the traditional one-dimensional unequal error protection (1D UEP) scheme. Comparing the proposed method with the 1D UEP scheme on SNR layers, our method gives up to 0.81-dB improvement for some video sequences 相似文献
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SVC在无线信道传输中的非均衡差错保护 总被引:1,自引:0,他引:1
针对H.264的可伸缩视频编码扩展标准(SVC)在噪声信道中的传输,采用低密度奇偶校验码(LDPC)提出一种非均衡差错保护的方案。在所提的方案中,根据时间、分辨率和质量把原视频序列按重要性分成不同的层。由于不同层的数据对错误的敏感性不同,对其进行不同码率的LDPC信道编码,实现非均衡差错保护。根据视频流中每一帧不同层的PSNR增量不同,和不同信道码率下正确解码的概率不同,反复计算每一帧所有码率组合的PSNR增量值并找出最大组,从而进行信道编码并传输。实验表明,在相同的平均码率条件下,提出的方案相比其他方案的PSNR值增加了2.8 dB,更适合无线信道的传输。 相似文献
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A new unequal error protection scheme based on FMO 总被引:1,自引:1,他引:0
This paper presents a novel scheme for video transmission over error-prone networks. The proposed scheme exploits the error
resilient features of H.264/AVC and employs an unequal error protection (UEP) approach to protect effectively the streams.
A novel algorithm is proposed to classify macroblocks into slice groups using the explicit mode of Flexible Macroblock Ordering
(FMO). A rate distortion optimized algorithm is used to assign unequal amounts of FEC protection to the resulting slice groups
according to their importance. In addition, a Converged Motion Estimation (CME) is proposed to further improve the proposed
UEP scheme. The idea behind the CME is to make the macroblocks be referenced in a skewed manner, such that highly important
macroblocks are converged on only a few and the use of redundancy for error protection is efficient. Simulation results show
the superiority of the proposed method over other approaches for transmission of H.264/AVC streams. 相似文献
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吴永娜 《数字社区&智能家居》2006,(12):59-61
简要介绍Philips公司的多媒体数字信号处理器PNX1500,重点阐述以PNX1500为核心实现可视电话终端的一种方案。本方案按照ITU-T制订的H.324系列标准协议,对输入音频和视频信息分别进行了基于G.723.1协议和H.263标准的信源编码,然后,根据信息分组复用H.223标准和通信控制规程H.245标准在PSTN或在ADSL上进行传输。 相似文献
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吴永娜 《数字社区&智能家居》2006,(35)
简要介绍Philips公司的多媒体数字信号处理器PNX1500,重点阐述以PNX1500为核心实现可视电话终端的一种方案。本方案按照ITU-T制订的H.324系列标准协议,对输入音频和视频信息分别进行了基于G.723.1协议和H.263标准的信源编码,然后,根据信息分组复用H.223标准和通信控制规程H.245标准在PSTN或在ADSL上进行传输。 相似文献
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《Computer Networks》1999,31(3):205-223
The Telecommunication Sector of the International Telecommunication Union (ITU-T) has developed a series of recommendations together comprising the H.323 system that provides for multimedia communications in packet-based (inter)networks. This series of recommendations describe the types and functions of H.323 terminals and other H.323 devices as well as their interactions. The H.323 series of recommendations includes audio, video and data streams, but an H.323 system minimally requires only an audio stream to be supported. Motivated by straightforward interoperability with the ISDN and PSTN networks and a variety of other protocols, the recommendation H.323 has been accepted as being the standard for IP telephony, developed by the ITU-T and broadly backed by the industry—which is also adopted by both the Voice over IP (VoIP) forum and the European Telecommunication Standards Institute (ETSI). This paper presents an overview of the H.323 system architecture with all its functional components and protocols and points out all the related specifications. 相似文献
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根据H.264标准的数据分类功能,提出一种数据的不平等保护策略。该策略利用信道的反馈信息预测信道丢包率,调整H.264视频码流各分类区的信道码率。实验结果表明,该策略能有效的提高视频码流的误码鲁棒性。 相似文献
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谢亮 《小型微型计算机系统》2006,27(8):1588-1591
针对多媒体无线通信的特点,提出了结合了自适应纠错技术与联合优化技术所提出的一种新策略.充分考虑了联合编码的自适应纠错特性和联合优化特性,在联合优化特性下分析了优化的信源编码算法和优化的信道编码算法.实验仿真的结果表明,该方法能够使图像数据在高码率下达到较好的抗噪性能. 相似文献
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提出了一种联合信源信道编码(JSCC)方案。首先,构造了一种具有重量递增奇偶校验矩阵的非规则LDPC码(WIPC-LDPC),实现非规则LDPC(Irregular LDPC)码比特节点按列重递增的顺序排列。然后,针对JPEG2000码流分层结构的特点,把不同质量层的JPEG2000码流成功地映射到WIPC-LDPC不同度数的比特节点上,以达到对不同重要级别码流的不等错误保护(UEP),从而达到优化重建图像质量和视觉效果的目的。仿真结果表明,与采用随机构造校验矩阵的非规则LDPC码进行等错误保护(EEP),以及采用RCPC、RS码进行不等错误保护的JPEG2000码流相比,JSCC方案提高了重建图像的PSNR,改善了重建图像的主观视觉效果。 相似文献
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针对差错信道下视频信源的不等差错保护问题,设计一个新的信道码码率分配策略,对一个图片组中不同位置的帧给予不同强度的保护。该策略考虑了视频信源的误码扩散问题,分析了差错掩盖方法与信道失真计算的关系,通过在编码端有效估计信道差错所引入的失真并建立最优码率分配问题,利用遗传算法快速得到最优的信道码码率分配方案。实验采用H.264视频编码标准,结果证明该策略能较好地提升视频传输系统性能。 相似文献
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介绍了一款基于富士通公司SoC芯片MB93461的宽带可视电话系统设计及实现。MB93461芯片采用VLIW结构,主频可达400MHz,内部集成媒体处理单元,可实现CIF大小的H.263/MPEG4视频实时编解码,通过集成视频IO,简化了外围电路设计。该系统兼容H.323/SIP协议栈,实现了视音频双向实时通信(每秒25帧H.263 CIF图像视频编解码;语音支持G.711和G.729标准)。该平台还实现了PSTN旁路功能,并运行uClinux操作系统。 相似文献
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根据H.264标准的数据分类功能,提出一种数据的不平等保护策略。该策略利用信道的反馈信息预测信道丢包率,调整H.264视频码流各分类区的信道码率。实验结果表明,该策略能有效的提高视频码流的误码鲁棒性。 相似文献
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Ruiz Reyes N. Vera Candeas P. 《IEEE transactions on audio, speech, and language processing》2010,18(3):447-460