A Survey on Video Transmission Techniques <s> A. Introduction <s> This article focuses on the compressed representations of pictures. The representation does not affect how many bits get from the Web server to the laptop, but it determines the usefulness of the bits that arrive. Many different representations are possible, and there is more involved in their choice than merely selecting a compression ratio. The techniques presented represent a single information source with several chunks of data ("descriptions") so that the source can be approximated from any subset of the chunks. By allowing image reconstruction to continue even after a packet is lost, this type of representation can prevent a Web browser from becoming dormant. <s> BIB001 </s> A Survey on Video Transmission Techniques <s> A. Introduction <s> A novel error concealment algorithm based on a stochastic modeling approach is proposed as a post-processing tool at the decoder side for recovering the lost information incurred during the transmission of encoded digital video bitstreams. In our proposed scheme, both the spatial and the temporal contextual features in video signals are separately modeled using the multiscale Markov random field (MMRF). The lost information is then estimated using maximum a posteriori (MAP) probabilistic approach based on the spatial and temporal MMRF models; hence, a unified MMRF-MAP framework. To preserve the high frequency information (in particular, the edges) of the damaged video frames through iterative optimization, a new adaptive potential function is also introduced in this paper. Comparing to the existing MRF-based schemes and other traditional concealment algorithms, the proposed dual MMRF (DMMRF) modeling method offers significant improvement on both objective peak signal-to-noise ratio (PSNR) measurement and subjective visual quality of restored video sequence. <s> BIB002 </s> A Survey on Video Transmission Techniques <s> A. Introduction <s> The problem of concealment in video communication is becoming increasingly important because of the growing interest in video delivery over unreliable channels such as wireless networks and the Internet. This paper reviews the necessity of error concealment, current error concealment techniques. These techniques are described in two categories according to temporal concealment methods and spatial errorconcealment methods.Lastly, the paper tries to analyze the direction of the development of error concealment. <s> BIB003 </s> A Survey on Video Transmission Techniques <s> A. Introduction <s> An algorithm combining source statistics and network congestion control for robust video transmission over wireless network is proposed in this paper.Based on scene modeling and characteristic analyzing,all layers generated by scalable coding are classified into several types and two queuing are made respectively according to their contribution to network congestion and to the quality of reconstructed video.Then the source rate,unequal error protection level and congestion control strategy are dynamically adjusted according to different network status in which the packet loss is caused by network congestion or by unreliable transmission in wireless channel.The simulation results show that the proposed method can achieve better results than MPEG-4 video source coding with fixed rate Turbo coding and than the one which dynamically adjusting source coding and channel coding rates and using network congestion control method of selectively dropping I,B or P packets. <s> BIB004 </s> A Survey on Video Transmission Techniques <s> A. Introduction <s> A novel three-dimension data interleaving method is proposed for video data transmission over wireless OFDM channels,where the three-dimensional interleaving includes interleavings in the spatial domain,frequency domain and temporal domain.The interleaving in the spatial domain is to uniformly disperse the burst bit-errors over the picture area.The frequency domain interleaving is to transmit adjacent slices over spaced sub-channels,which facilitates temporal or spatial error concealment.Temporal interleaving is to transport different slices in one OFDM sub-carrier in changed time intervals.It can provide credible reference picture for inter-frame prediction coding,and thus the error propagation over frames can be avoided,and the error concealment can be exploited too.System integrating the three-dimension data interleaving method with the multi-reference picture selection(RPS) and error concealment can efficiently improve the quality of the reconstructed video transmitted over wireless OFDM channels.Simulation results show that the proposed method can increase the PSNR of reconstructed video transmitted over OFDM wireless channels by over 4dB under different channel conditions. <s> BIB005 </s> A Survey on Video Transmission Techniques <s> A. Introduction <s> In this paper, we propose an optimal strategy for the transmission of scalable video over packet-based multiple-input multiple-output (MIMO) systems. The scalable extension of H.264/AVC that provides a combined temporal, quality and spatial scalability is used. For given channel conditions, we develop a method for the estimation of the distortion of the received video and propose different error concealment schemes. We show the accuracy of our distortion estimation algorithm in comparison with simulated wireless video transmission with packet errors. In the proposed MIMO system, we employ orthogonal space-time block codes (O-STBC) that guarantee independent transmission of different symbols within the block code. In the proposed constrained bandwidth allocation framework, we use the estimated end-to-end decoder distortion to optimally select the application layer parameters, i.e., quantization parameter (QP) and group of pictures (GOP) size, and physical layer parameters, i.e., rate-compatible turbo (RCPT) code rate and symbol constellation. Results show the substantial performance gain by using different symbol constellations across the scalable layers as compared to a fixed constellation. <s> BIB006 </s> A Survey on Video Transmission Techniques <s> A. Introduction <s> We propose a novel solution to the problem of robust, low-latency video transmission over lossy channels. Predictive video codecs, such as MPEG and H.26x, are very susceptible to prediction mismatch between encoder and decoder or ldquodriftrdquo when there are packet losses. These mismatches lead to a significant degradation in the decoded quality. To address this problem, we propose an auxiliary codec system that sends additional information alongside an MPEG or H.26x compressed video stream to correct for errors in decoded frames and mitigate drift. The proposed system is based on the principles of distributed source coding and uses the (possibly erroneous) MPEG/H.26x decoder reconstruction as side information at the auxiliary decoder. The distributed source coding framework depends upon knowing the statistical dependency (or correlation) between the source and the side information. We propose a recursive algorithm to analytically track the correlation between the original source frame and the erroneous MPEG/H.26x decoded frame. Finally, we propose a rate-distortion optimization scheme to allocate the rate used by the auxiliary encoder among the encoding blocks within a video frame. We implement the proposed system and present extensive simulation results that demonstrate significant gains in performance both visually and objectively (on the order of 2 dB in PSNR over forward error correction based solutions and 1.5 dB in PSNR over intrarefresh based solutions for typical scenarios) under tight latency constraints. <s> BIB007 </s> A Survey on Video Transmission Techniques <s> A. Introduction <s> As the demand for network video surveillance equipment,this paper designed and realized the wireless video surveillance system based on 3G and H.264 technology.The system integrated video compression,embedded systems and wireless communications and related technologies.As the rate control algorithm of H.264 emphasis too much on versatility without taking into account about the high error rate of wireless networks,and with limited processing power of embedded terminals,the system optimized rate control algorithm of H.264 to fit these conditions.Experimental results show that there is no significant increase in the coded bits,but the image PSNR value has increased,and thus achieves a better rate control effect. <s> BIB008
As we all know, the current Internet only provides 'best effort' service at network layer to simplify network implementation, i.e., it is only responsible for sending in network rather than paying attention to whether packets can arrive accurately according to related order within specified time or packets are lost or not, that is, it cannot provide quality of service (QoS) for packet transmission  . This transmission mechanism is appropriate for abrupt data transmission in network  . Aiming at the foregoing problems, researchers propose different video transmission plans, such as classification method BIB004 BIB006 : it classifies code stream and transmits different types of video data dynamically according to current status of network. Supplementary information method BIB007 BIB001 : when data are sent, extraneous information needed by encoding and decoding is also sent to solve the QoS problem of video transmission. Environmental adaptation method  BIB005 : according to different network environment, different transmission modes are utilized to carry out video transmission; and data partitioning method  BIB002 : data are partitioned according to their features and then transmitted. When traditional video analysis system does work like analysis and recognition of video content, such work needs to be realized by people. Since its workload and labor intensity are large and faults may be caused easily when analysis are carried out artificially, intelligentization is becoming a development direction of video analysis. One of the most important problems of the field of video intelligent analysis is how to find and analyze useful information automatically from a large number of video images BIB008 . It is essential for the video intelligent analysis to have the following functions, such as recognizing objects automatically, perceiving changes in target objects and having the ability to realize timely and alarm automatically when abnormal conditions appear. When real-time video data are transmitted on network, the frame rate of correct decoding of the receiving end will be much lower than the sending frame rate of the sending end if video data frames are sent under the situation that bandwidth is not enough or packet loss probability is high for impacts of factors like bandwidth and packet loss probability. Two types of errors BIB003 may be caused when videos are transmitted: erasable errors and random order ones. Erasable errors are caused by burst error of packets in network, which are short-term system errors. Random order errors results from defects existing in physical channels (such as order insertion, deletion or reversal). Since most of video coding techniques adopt variable-length encoding (VLC) technique, the two types of errors do not have much difference f or video transmission. To realize detection of errors and error concealment, redundancy processing is often needed. Generally speaking, redundancy may exist in source encoder, entropy encoder and channel encoder.