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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
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THANG Truong Cong KIM Young Suk RO Yong Man KANG Jungwon KIM Jae-Gon 《浙江大学学报(A卷英文版)》2006,7(5):764-772
INTRODUCTION Scalable video coding (SVC) (Schwarz et al., 2004) is the most promising video format for appli- cations of collaborative communication. First, SVC format, which is extended from the latest advanced video coding (AVC), is appropriate for creating a wide variety of bitrates with high compression effi- ciency. Second, an original SVC bitstream can be easily truncated in different ways to meet various characteristics and variations of devices and connec- tions. The scalabil… 相似文献
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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。 相似文献
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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
5.
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
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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… 相似文献
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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
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This paper presents an efficient VLSI architecture of the contest-based adaptive variable length code (CAVLC) decoder with power optimized for the H.264/advanced video coding (AVC) standard. In the proposed design, according to the regularity of the codewords, the first one detector is used to solve the low efficiency and high power dissipation problem within the traditional method of table-searching. Considering the relevance of the data used in the process of runbefore’s decoding, arithmetic operation is combined with finite state machine (FSM), which achieves higher decoding efficiency. According to the CAVLC decoding flow, clock gating is employed in the module level and the register level respectively, which reduces 43% of the overall dynamic power dissipation. The proposed design can decode every syntax element in one clock cycle. When the proposed design is synthesized at the clock constraint of 100 MHz, the synthesis result shows that the design costs 11 300 gates under a 0.25 μm CMOS technology, which meets the demand of real time decoding in the H.264/AVC standard. 相似文献
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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… 相似文献
10.
H.264/MPEG-4 AVC standard appears highly competitive due to its high efficiency, flexibility and error resilience. In order to maintain universal multimedia access, statistical multiplexing, or adaptive video content delivery, etc., it induces an immense demand for converting a large volume of existing multimedia content from other formats into the H.264/AVC format and vice versa. In this work, we study the remultiplexing and resynchronization issue within system coding after transcoding, aiming to sustain the management and time information destroyed in transcoding and enable synchronized decoding of decoder buffers over a wide range of retrieval or receipt conditions. Given the common intention of multiplexing and synchronization mechanism in system coding of different standards, this paper takes the most widely used MPEG-2 transport stream (TS) as an example, and presents a software system and the key technologies to solve the time stamp mapping and relevant buffer management. The solution reuses previous information contained in the input streams to remultiplex and resynchronize the output information with the regulatory coding and composition structure. Experimental results showed that our solutions efficiently preserve the performance in multimedia presentation. 相似文献
11.
刘骋 《武汉职业技术学院学报》2005,4(1):52-55
H．264是新一代视频编码标准。本文分析了H．264的分层结构和主要编码技术，探讨了其在性能改进方面的研究成果，并展望了其在多个领域中的应用前景。 相似文献
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Asymmetric stereoscopic video coding can take advantage of binocular suppression in human vision by representing one of the two views in lower quality.This paper proposes a bit allocation strategy for asymmetric stereoscopic video coding.In order to improve the accuracy of bit allocation and rate control in the left view,a proportionalintegral-derivative controller is adopted.Meanwhile,to control the quality fluctuation between consecutive frames of the left view,a quality controller is adopted.Besides,a fuzzy controller is proposed to control the variation in quality between the left and right views by comparing the PSNR disparity of two views with a fixed threshold,which is used to quantize the binocular psycho-visual redundancy and adjust the quantization parameter (QP) of the right view correspondingly.The proposed algorithm has been implemented in H.264/AVC video codec,and the experimental results show its effectiveness in rate control while keeping a good quality for the left view,and fewer bits are allocated for the right view so that the overall bit rate is saved by 7.2% at most without the loss of subjective visual quality for stereoscopic video. 相似文献
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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%. 相似文献
14.
何书前 《海南师范学院学报》2006,19(3):229-233
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。 相似文献
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16.
分析了高职院校校园中进行视频监控的必要性,对整个视频监控系统的关键技术包括H。264/AVC视频编解码、移动流媒体技术等进行研究,设计了一种应用于手持智能终端的视频监控系统,详细阐述了其体系结构和客户端实现,为高职院校建设数字化校园视频监控提供了一种新的方案。 相似文献
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A fast motion estimation algorithm for mobile communications 总被引：1，自引：0，他引：1
CHEN Guo-bin 《浙江大学学报(A卷英文版)》2006,7(Z1)
The limitation of processing power, battery life and memory capacity of portable terminals requires reducing encoding complexity in mobile communications. Motion estimation (ME) is the most computationally intensive module in a typical video codec, which determines not only the encoder's performance but also the reconstructed video quality. In this paper, a fast ME algorithm for H.264/AVC baseline profile coding is proposed based on the analysis of motion vector field and error surface, and the statistical distributions of different type macroblocks (MBs). Simulation results showed that: in comparison with MVFAST, the proposed algorithm can decrease the computational load over 7.2% with no requirement of expanding memory capacity while maintaining the same video quality as MVFAST. Furthermore, its simplicity makes it easy to be implemented on hardware. 相似文献
18.
The H.264/AVC video coding standard uses an intra prediction mode with 4×4 and 16×16 blocks for luma and 8×8 blocks for chroma. This standard uses the rate distortion optimization （RDO） method to determine the best coding mode based on the compression performance and video quality. This method offers a large improvement in coding efficiency compared to other compression standards, but the computational complexity is greater due to the various intra prediction modes. This paper proposes a fast intra mode decision algorithm for real-time encoding of H.264/AVC based on the dominant edge direction （DED）. The DED is extracted using pixel value summation and subtraction in the horizontal and vertical directions. By using the DED, three modes instead of nine are chosen for RDO calculation to decide on the best mode in the 4×4 luma block. For the 16×16 luma and the 8 × 8 chroma, only two modes are chosen instead of four. Experimental results show that the entire encoding time saving of the proposed algorithm is about 67% compared to the full intra search method with negligible loss of quality. 相似文献
19.
勾占锋 《佳木斯教育学院学报》2012,(7):406-406
本文介绍了一种不同于其它软件算法实现H.264视频压缩技术的嵌入式网络视频服务器的设计方案,采用以硬件方式实现H.264视频压缩的双核处理器,配以音视频解码模块、以太网模块、存储模块、各种接口模块等,设计出真正实现H.264的网络视频服务器。 相似文献