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

In this work, a new method to deal with the unconnected pixels in motion compensated temporal filtering (MCTF) is presented, which is designed to improve the performance of 3D lifted wavelet coding. Furthermore, multiple description scalable coding (MDSC) is investigated, and novel MDSC schemes based on 3D wavelet coding are proposed, using the lifting imple- mentation of temporal filtering. The proposed MDSC schemes can avoid the mismatch problem in multiple description video coding, and have high scalability and robustness of video transmission. Experimental results showed that the proposed schemes are feasible and adequately effective.

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

Standard-compatible multiple description coding (MDC) and layered coding (LC) are efficient ways to ensure erasure resilient, scalable transmission of encoded multimedia sources via RTP, allowing a gradual degradation of the application quality with increasing packet loss rate and decreasing bandwidth/throughput on the network. In this paper we review the stan- dard-compatible framework proposed to IETF. Alternative techniques such as robust source coding and channel coding techniques (ARQ: automatic repeat request, FEC: forward error correction) are presented; their integration into the proposed framework is also discussed. The performances of MDC and LC either coupled with channel coding or not, are summarized by reference to current literature. Typical cases and examples are illustrated.

Multiple description coding with spatial-temporal hybrid interpolation for video streaming in peer-to-peer networks

In this paper, we present an innovative design of multiple description coding with spatial-temporal hybrid interpola- tion (MDC-STHI) for peer-to-peer (P2P) video streaming. MDC can be effective in P2P networks because the nature of overlay routing makes path diversity more feasible. However, most MDC schemes require a redesign of video coding systems and are not cost-effective for wide deployment. We base our work on multiple state video coding, a form of MDC that can utilize standard codecs. Two quarter-sized video bit streams are generated as redundancies and embedded in the original-sized streams. With MDC-STHI, the nodes in P2P network can adjust the streaming traffic to satisfy the constraints of their devices and network environment. By design, the redundancies are used to compensate for missing frames, and can also be streamed independently to fulfill certain needs of low rate, low resolution applications. For better error concealment, optimal weights for spatial and temporal interpolation are determined at the source, quantized, and included in redundancies.

Improved Multiple Descriptions Sinusoidal Coder Adaptive to Packet Loss Rate

To make the multiple descriptions codec adaptive to the packet loss rate, which can minimize the final distortion, a novel adaptive multiple descriptions sinusoidal coder （AMDSC） is proposed, which is based on a sinusoidal model and a noise model. Firstly, the sinusoidal parameters are extracted in the sinusoidal model, and ordered in a decrease manner. Odd indexed and even indexed parameters are divided into two descriptions. Secondly, the output vector from the noise model is split vector quantized. And the two sub-vectors are placed into two descriptions too. Finally, the number of the extracted parameters and the redundancy between the two descriptions are adjusted according to the packet loss rate of the network. Analytical and experimental resuits show that the proposed AMDSC outperforms existing MD speech coders by taking network loss characteristics into account. Therefore, it is very suitable for unreliable channels

Iterative Soft Decoding of Multiple Description Image over Wireless Channel

Motivated by recent results in multiple description image coding over wireless networks, we propose a scheme for transmission of multiple descriptions through hybrid packet loss and additive white Gaussian noise channel. Each description is coded into multiple bitstreams by applying SPIHT coding on wavelet trees along spatial orientations and each stream is further compressed using arithmetic code. Use of error resilient entropy coding (EREC) is proposed in literature for synchronization requirement of variable length codes, but EREC is not compatible with iterative soft-in soft-out decoding of arithmetic code at the receiver. We propose the application of EREC assisted by state and tail bits (ERECST) in conjunction with iterative decoding of arithmetic code at receiver for reconstructing the multiple description coded image over packet loss and Gaussian noise channel. Experimental results demonstrate that an additional gain of 7 dB in PSNR is obtained over existing scheme.

LOW-COMPLEXITY REDUNDANCY INSERTION IN MULTIPLE DESCRIPTION CODING

Multiple description coding has recently been proposed as a joint source and channel coding to solve the problem of robust image transmission over unreliable network, and it can offer a variety of tradeoff between signal redundancy and transmission robustness. In this letter, a novel pre- and post-processing method with flexible redundancy insertion for polyphase downsampling multiple de- scription coding is presented. The proposed method can be implemented as pre- and post-processing to all standards for image and video communications, with obvious advantages. Simulation results show that this approach can reduce the computational complexity while provide a flexible redundancy in- sertion to make the system robust for any packet loss situation over different networks.

M3FEC:Joint Multiple Description Coding and Forward Error Correction for Interactive Multimedia in Multiple Path Transmission

The best-effort internet has inherent limitations on the end-to-end performance for interactive multimedia communications. This paper presents a multiple description coding （MDC） and forward error correction （FEC） based multiple path transmission schemes for interactive multimedia （M3FEC）, which improves the end users’ experience by maximizing a rate-distortion （R-D） based optimization problem. The proposed model considers both the network diversity and the application’s stringent requirements, and combines the individual merits of the three promising technologies of multiple path overlay routing, MDC and FEC. Extensive numerical analysis and PlanetLab experiments demonstrate that M3FEC successfully combats packet losses, error propagation, and unpredictable network dynamics. This method also significantly increases distortion for interactive multimedia by over 10 dB than traditional IP-layer single path transmission in poor network environments, and outperforms the performance achieved by using MDC or FEC alone.

Robust multiple description distributed video coding using optimized zero-padding

Distributed video coding （DVC） arouses high interests due to its property of low-complexity encoding. This paper proposes a robust multiple description DVC （MDDVC） under the constraint of low-complexity encoding. In MDDVC, zeros are padded to each frame and the resulting big-size video is divided into multiple descriptions. Then, each description is compressed by s hybrid DVC （HDVC） codec and trans- mitted over different channel. When one channel does not work, the lost HDVC description is estimated by the received from other channel, which guarantees the robustness of the system; MDDVC moves the complex motion estimation totally to the decoder so it features low-complexity encoding. In the pre-processing, an optimized zero-padding is also proposed to improve the performance. Experimental results exhibit that the proposed MDDVC scheme achieves better rate-distortion performance and robustness than the referenced especially when packet-loss rate is high.

Chessboard-interpolation-based multiple description video coding

To enhance the robustness of video transmission over noisy channels, this paper presents a multiple description video coding algorithm based on chessboard-interpolation. In the algorithm, the input image is decomposed according to the chessboard pattern, and then interpolated to produce two approximate images with the same resolution. Consequently, the state-of-the-art DCT+MC (Discrete Cosine Transform + Motion Compensation) video codec is independently applied to the two approximate images to generate two descriptions of the original image. In this framework, a fairely good reconstructed image quality is obtained when two descriptions are received simultaneously, while an acceptable reconstructed image quality could be yielded if only one description is available. Moreover, the mismatch between the encoder and the decoder could be effectively controlled through partial coding of the difference signal between two descriptions. In bidirectional video communications, a drift control scheme is further proposed, in which the error drift could be eliminated after the encoder imitating the error concealment actions of the decoder. Since the inherent correlation among adjacent blocks of DCT+MC video coding is efficiently exploited, this algorithm has a better redundancy-rate-distortion (RRD) performance than other multiple description algorithms. Simulation results show that the proposed algorithm is fairly robust while preserves a high compression rate. A more constant reconstructed image quality is achieved over extremely noisy channels, compared with traditional single description coding. In addition, it is observed that the mismatch and the error drift are effectively controlled.

Efficient Multiple Description Scalable Video Coding Scheme Based on Weighted Signal Combinations

A simple, efficient multiple description coding （MDC） algorithm was developed based on weighted signal combinations. The scheme uses the standard video encoder with a pre-processing stage to generate multiple descriptions. The decoder then uses a post-processing algorithm to combine the descriptions to provide better image quality. A scalable codec in the MDC system allows the system to provide multiple descriptions and scalability at the same time. In addition, since the different scalable descriptions may have different qualities, a simple averaging process is not optimal. An optimal weighted combination of the two descriptions was developed based on the signal to noise ratios. Compared with the simple average combination, the algorithm significantly improved the video quality, especially with large quality differences between the two descriptions, with gains of up to 3.56 dB.

Multiple description video coding based on residuum compensation

As one of the focus areas of robust video coding and transmission, multiple description video coding has attracted comprehensive attention. The low coding efficiency of multiple description video coding is always the major challenge in this field. In order to improve the performance of multiple description video coding, this paper proposes a scheme based on residuum compensation. In this scheme, each original video frame is encoded with a traditional encoder first to get the first description. Then the error residuum of each coded frame is added up to the corresponding original frame and the resulting compensated frame is encoded by another traditional encoder to generate the second description suc- cessively. This work uses JM10.0 of H.264/AVC as video coding codec to conduct the experiments. The experimental results show that the proposed scheme has good coding performance. Compared to state of art traditional single description encoder, the efficiency can be as high as 90%, he. the redundancy is only 10% to 20%.

Multipath Routing of Multiple Description Coded Images in Wireless Networks

Multiple description coding （MDC） generates multiple decodable bitstreams for a source to combat informa- tion loss. In this paper, multipath routing problem for two-description coded images is investigated for traditional and coded wireless networks without and with coding capability at intermediate nodes, respectively. Firstly, we formulate an interference-aware MDC multipath routing for traditional networks by employing a time-division link scheduling method to eliminate wireless interference, and ultimately obtain an optimal path selection corresponding to the minimum achievable distortion. Secondly, for coded networks, we evaluate practical wireless network coding （NC） in delivering descriptions of multiple unicast sessions. While NC increases maximum supporting flow rate of MDC descriptions in wireless networks, possible undecodability of NC mixed information is alleviated by MDC. To minimize achievable distortion, a proposed interference-and-coding-aware MDC multipath routing strikes a good balance between minimizing side effect of wireless interference avoidance and maximizing NC opportunity. Simulation results validate the effectiveness of the two proposed schemes.

Complete Multiple Description Mesh-Based Video Coding Scheme and Its Performance

This paper proposes a multiple description (MD) mesh-based motion coding method, which generates two descriptions for mesh-based motion by subsampling the nodes of a right-angled triangular mesh and dividing them into two groups. Motion vectors associated with the mesh nodes in each group are transmitted over distinct channels. With the nodes in each group, two other regular triangular meshes besides the original one can be constructed, and three different prediction images can be reconstructed according to descriptions available. The proposed MD mesh-based motion coding method is then combined with the pairwise correlating transform (PCT), and a complete MD video coding scheme is proposed. Further measures are taken to reduce the mismatch between the encoder and decoder that occurs when only one description is received and the decoder reconstruction is different from the encoder. The performance of the proposed scheme is evaluated using computer simulations, and the results show, compared to Reibman's MD transform coding (MDTC) method, the proposed scheme achieves better redundancy rate distortion (RRD) performance. In packet loss scenario, the proposed scheme outperforms the MDTC method.

无线传感器网络MDC视频传输的跨层多径路由协议

将网络协议栈的跨层优化设计思想应用于多媒体无线传感器网络,提出一种基于视频编码峰值信噪比最优的跨层多径路由协议.在跨层多径路由模型中,以最大化应用层的多描述编码(MDC)峰值信噪比作为优化目标,通过物理层的丢包率测量和MDC层的信道容量估计联合确定网络层的多径路由属性,MDC的每个描述被映射到多条链路独立的路径上分别传输,最终在Sink节点进行汇聚.对随机生成的网络拓扑求取最小跳数节点的独立两路径路由和跨层多径路由,将Foreman视频分割成2个描述编码视频沿不同路由进行传输,仿真结果验证了跨层多径路由能够降低丢包率和提高平均PSNR.跨层多径路由协议能够提高MDC视频在无线传感器网络中的传输质量.

一种基于F-MDC的WMSN自适应算法

无线多媒体传感器网络中,相机结点采集的图像数据量非常大,而且还出现在随时变化的环境中,传输前需要对图像进行压缩,为了满足无线多媒体传感器网络应用的高图像质量、低耗能的需求,结合JPEG2000算法的R-D斜率优化,"T+2D"编码框架的开环运动补偿编码结构,MDC编码的多重描述的独立性,以及可分级编码的数据的优先级等特性,提出了一种自适应的多描述编码方案——F-MDC,实现了高图像质量,相对解决了编码低复杂度,低耗能的问题,又由分布式编码的低复杂度优点,提出了将自适应的多描述编码融入分布式编码中去的思想,以求更加适应无线传感器网络状况.

基于减格辅助线性预编码的MIMO图像MDC设计

为了解决实际的无线传输环境中由空间相关性的存在导致的MIMO MDC图像传输系统性能下降的问题,保证图像通信的质量,对基于SPIHT算法所形成的MDC各个码流采用RS码进行不等保护,利用ZF或MMSE减格辅助线性预编码处理,提出一种适宜4×4 MIMO相关信道的MDC传输方案,并在此基础上研究了其在信道确知和信道估计情况下的性能。实验结果表明,基于减格辅助预编码处理的MIMO MDC设计方案比MD-SPIHT方案在性能上有明显提升,因此,更适宜于MIMO空间相关信道。

一种基于FEC-MDC的多用户码流快速分割算法

基于前向纠错的多描述编码(FEC-MDC)是一种在包丢失严重的信道中传输可分级图像和视频数据的有效方法。本文针对单一信源多用户的网络应用模型,研究了在描述数N固定的情况下,根据各信道传输码率的不同,通过调整发送包的长度L实现最佳码流传输的问题,提出了一种码流快速优化分割的改进算法。该算法基于已计算出的参考信道码流分割方案,在期望失真最小的准则下,首先通过在各个目标码率的邻域进行搜索计算,将搜索域分割为低码率部分和高码率部分,然后在高码率部分进行粗的二次搜索,得到最终码流分割,这不仅减少了搜索次数,降低了计算的复杂度,而且保证搜索到在该码率情况下的最佳分割。实验结果表明,本文提出的改进算法与之前的方法相比能够得到相同的平均PSNR,但是总的运算时间减少了近40%。

MDC融合多径路由的无线图像传输方法

针对具有时间约束图像的无线网络传输中的数据出错和丢失问题,提出一种多重描述编码(multiple description coding,MDC)结合网状多径路由的图像传输方法。源节点利用MDC将图像帧分成多个等同重要的描述,利用提出的多径路由策略寻找多条边不相交路径,并选择合适的中间合并点对描述进行合并,利用链接错误信息对受损描述进行中间修复,目的节点利用2×2过滤器和像素错误概率权重进行解码,根据其空间邻居插补丢失或损坏的像素。实验结果表明,提出的方法能够有效提高无线信道的容错性能,实现高信噪比图像传输。

A Centralized Algorithm for Assigning MDC Video Application in Virtual Network

Providing services on demand is a major contributing factor to drive the increasingly development of the software defined network. However, it should supply all the current popular applications before it really attains widespread development. Multiple Description Coding(MDC) video applications, as a popular application in the current network, should be reasonably supported in this novel network virtualization environment. In this paper, we address this issue to assign MDC video application into virtual networks with an efficient centralized algorithm(CAMDV). Since this problem is an NP-hard problem, we design an algorithm that can effectively balance the user satisfaction and network resource cost. Previous work just builds a global multicast tree for each description to connect all the destination nodes by breadth-first search strategy or shortest path tree algorithm. But those methods could not achieve an optimal balance or a high-level user satisfaction. By introducing the hierarchical clustering scheme, our algorithm decomposes the whole mapping procedure into multicast tree construction and multipath description distribution. A serial of simulation experiments show that our centralized algorithm could achieve a better performance in balancing the user satisfaction and average mapping cost in comparison with its rivals.

An Improved MDC-Based ORB-DCT Method for Video Streaming over the Internet

One of the most interesting questions of video streaming over the Intemet is packet loss. Some error resilient technologies have been proposed to overcome quality decrease of reconsixucted video occurred due to packet loss, in which optimized reconstructionbased DCT （ORB-DCT） utilizes two-direction interleaving. An improved ORB-DCT （IORB-DCT）, which uses four-direction interleaving, is proposed in this paper. Experimental results are demonstrated to verify the effectiveness of the proposed IORB-DCT.