Access links are often times the bottlenecks of wireless wide area networks (WWAN). The prevalent use of multimedia applications on mobile devices introduces an ever increasing traffic load on WWAN access links, leadi...
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Access links are often times the bottlenecks of wireless wide area networks (WWAN). The prevalent use of multimedia applications on mobile devices introduces an ever increasing traffic load on WWAN access links, leading to traffic congestion and unsatisfactory user experiences. In this paper, we introduce a mobile multipath cooperative network. In the system, multiple paths are dynamically established among cooperative devices over WWAN and WLAN so that multipledescriptions of a multimedia stream can be transported over distinct end-to-end paths between two mobiles. As a result, the capacities of multiple wireless access links can be utilized to enhance quality of experience of a multimedia application. We also introduce a MDC rate adaptation algorithm that jointly adapts the source coding rates among multiple paths. Our lab experiments show that real-time streaming with multiple description coding benefits significantly from the proposed cooperative network and subsequently enhance the quality of user experience for multimedia applications. (C) 2012 Elsevier B.V. All rights reserved.
In peer-to-peer video streaming, the robustness to peer and packet losses is regarded very important in order to enjoy a good quality of experience. multiple description coding (MDC) schemes are known to provide high ...
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In peer-to-peer video streaming, the robustness to peer and packet losses is regarded very important in order to enjoy a good quality of experience. multiple description coding (MDC) schemes are known to provide high robustness to packet losses. In peer-to-peer streaming in addition to high robustness, efficient controllability of data rate and redundancy among the data streams from peers is also vital. In this paper, a novel framework for scalable multiple description coding scheme for peer-to-peer video streaming is presented by addressing these requirements. The proposed MDC solution is based on the multipledescription scalar quantization (MDSQ) by addressing the joint decoding of unbalanced descriptions and addition of jointly decodable successive refinement layers to side descriptions. Firstly, the design conditions for MDSQ with constrained successive refinement to obtain scalable multipledescription streams where the bit streams can be truncated at any point to obtain lower quality spatial temporal descriptions are firstly proposed. Then the design conditions for joint decoding of two or more side descriptions from different multipledescription scalar quantizers, originating from various bin spread factors leading to controllable redundancy are proposed. These design conditions enable joint redundancy and data rate control for streams coming from different peers, thereby, enabling high robustness to packet losses as well as peer losses with the adaptability of redundancy levels and truncation of scalable streams. The proposed design constraints are used within the motion compensated temporal filtering (MCTF) framework to demonstrate its advancement in robust peer-to-peer video streaming. The results show significant improvements over conventional MDC based on simple MSDQ and over single description scalable video. (C) 2012 Elsevier B.V. All rights reserved.
Real-time data delivery over best-effort error-prone packet networks has invigorated the study of robust coding schemes, such as scalable multiple description coding (SMDC). In this context, the paper introduces a nov...
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Real-time data delivery over best-effort error-prone packet networks has invigorated the study of robust coding schemes, such as scalable multiple description coding (SMDC). In this context, the paper introduces a novel generic symmetric scalable multipledescription quantizer (SSMDSQ) which generates perfectly balanced source descriptions. Novel embedded index assignments are proposed which are used to realize high, as well as medium-to-low redundancy SSMDSQs. Compared to existing designs, it is shown that the proposed quantizer constructions exhibit superior distortion-rate (D-R) performance. Moreover, this paper describes an innovative extension of the Lloyd-Max algorithm in order to optimize symmetric and asymmetric scalable multipledescription quantizers. For a family of Generalized Gaussian (GG) source distributions, the proposed optimization algorithm yields on average a significant D-R performance gain over unoptimized quantizers. Furthermore, anchored in the designed SSMDSQs, an SMDC framework is established to realize packet-based transmission over erasure channels. In this framework, transmission strategies are determined for scenarios wherein the average packet loss rate over the transmission link is (a) unknown and (b) can be estimated at the encoder. For both scenarios, SMDC packetized transmission is simulated for a family of GG distributions. Experimental results confirm that, compared to contemporary schemes, the designed quantizer constructions (with or without optimization) account for a significant average gain in signal-to-noise ratio (SNR) for a wide range of packet loss rates.
It is known that in a peer-to-peer (P2P) network a peer node serves as both a receiver and a supplier, which enables uploading bandwidth of peer nodes to be utilized efficiently while relieving burden of the server no...
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It is known that in a peer-to-peer (P2P) network a peer node serves as both a receiver and a supplier, which enables uploading bandwidth of peer nodes to be utilized efficiently while relieving burden of the server node. This solves the scalability problem typically encountered in the traditional client-server model. However, frequent peer churn and varying bandwidth of peer nodes in P2P networks pose significant challenges for video streaming. These challenges can be addressed from both the P2P system design and the advanced video coding perspectives. In this paper, we first present a survey on the existing P2P video streaming systems that leverage the multiple description coding (MD coding or MDC) techniques, featured in providing strong error resilience for video delivery and supporting heterogeneity for peer nodes. Compared with layered coded video streaming, MD coded video streaming presents stronger robustness without requiring special provisions in P2P system design at a modest cost of compression efficiency, which is desirable in dynamic and error-prone P2P networks. In the MD coded video streaming, packet scheduling is critical to performance of mesh-based P2P systems. A new packet scheduling framework is formulated for receiver-driven MD coded video streaming, where a receiver collects peer nodes' information and generates a transmission schedule for MDC packets. In the proposed framework, a rate-distortion optimized packet selection scheme is developed to minimize the expected distortion subject to limited downloading bandwidth. Accordingly a rate-distortion based prioritized peer selection scheme is employed to choose an appropriate peer node for each of the selected packets. Simulation results validate the effectiveness of the proposed scheduling scheme and the advantage of MDC over layered coding in a network with frequent peer churn. (C) 2012 Elsevier B.V. All rights reserved.
multiple description coding (MDC) provides a means to combat erasure channels. Both rate and packet delay have significant contributions to end-to-end distortion of delay-sensitive sources. The previous works just con...
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multiple description coding (MDC) provides a means to combat erasure channels. Both rate and packet delay have significant contributions to end-to-end distortion of delay-sensitive sources. The previous works just considered exponential and fixed packet length distributions to evaluate the packet delay. In this letter, assuming a general (unknown) distribution with known average and variance of packet length, it is showed that average distortions of MDC and Single descriptioncoding (SDC) are upper bounded. Derived bounds are determined by encoding rate, packet arrival rate of network, acceptable delay threshold and first and second moments of packet length distribution.
When a vehicle requests a video streaming service from the Internet, it may not have enough bandwidth to receive good video quality. In order to resolve this problem, the vehicle is proposed to ask neighboring vehicle...
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When a vehicle requests a video streaming service from the Internet, it may not have enough bandwidth to receive good video quality. In order to resolve this problem, the vehicle is proposed to ask neighboring vehicles to help the video download process using a short-range wireless technique, i.e. Dedicated Short Range Communications (DSRCs). In this paper, this scenario is called cooperative streaming over vehicular networks. Since the topology of vehicular networks changes over time rapidly, three critical issues in the moving-vehicle-based cooperative streaming are: (i) how to form a cooperative group dynamically, (ii) how to schedule neighboring vehicles to help the video download process and (iii) how to estimate the possible change of network conditions. We propose corresponding control schemes to tackle the aforementioned issues in this paper. From the simulation results, we can find that different scheduling schemes are adaptive to different scenarios, and the proposed dynamic group formation scheme has better performance than that of periodic group formation scheme.
This paper proposes a novel and efficient two-description image coding scheme in the wavelet domain. Here, each description includes one basic description produced by pairwise correlating transform (PCT) and one enhan...
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ISBN:
(纸本)9781424421787
This paper proposes a novel and efficient two-description image coding scheme in the wavelet domain. Here, each description includes one basic description produced by pairwise correlating transform (PCT) and one enhanced description formed by quincunx sub-sampling. First, we partition the low-frequency wavelet coefficients into two groups. Then the PCT was applied between the two groups to generate two new correlated groups as two basic descriptions, which are coded and transmitted through two separate channels. Second, we can get two enhanced descriptions from the high-frequency wavelet coefficients of the highest-level decomposition by quincunx sub-sampling. And the Wavelet Domain Interpolation for tree Reconstruction (WDIR) is used to conceal coefficients loss in Wavelet-Trees when one enhanced description lost during transmission. Experimental results demonstrate that the proposed MDC scheme can achieve good coding performance.
In this paper a scalable multipledescription video coding approach based on embedded multipledescription scalar quantization (EMDSQ) is presented. The proposed approach enables the progressive transmission of video ...
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ISBN:
(纸本)9781424424221
In this paper a scalable multipledescription video coding approach based on embedded multipledescription scalar quantization (EMDSQ) is presented. The proposed approach enables the progressive transmission of video over unreliable channels with variable bandwidth. Experimental results show that in lossy transmission conditions the proposed embedded multiple description coding system yields better rate-distortion performance compared to single description video coding and can efficiently sustain 20% of losses.
A two-stage multipledescription predictive coding technique is proposed. A predictive encoder is used in the first stage of each description. The two encoders are designed to create staggered quantizers for the input...
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ISBN:
(纸本)9781424416424
A two-stage multipledescription predictive coding technique is proposed. A predictive encoder is used in the first stage of each description. The two encoders are designed to create staggered quantizers for the input, which allow further refinement of the joint reconstruction in the second stage. Theoretical analysis and simulation results show that this method is very efficient in the high rate multiple description coding of strongly correlated sources.
The development of an efficient and reliable multipledescriptions coding (MDC) scheme over lossy communication networks has been described. The advantage of MDC is that, if all the channels work, a high quality, poss...
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ISBN:
(纸本)9781424424085
The development of an efficient and reliable multipledescriptions coding (MDC) scheme over lossy communication networks has been described. The advantage of MDC is that, if all the channels work, a high quality, possibly lossless, reconstruction can be achieved from all the received descriptions. On the other hand, a lower but still acceptable quality can be achieved if some of the channels are not received at all. In this article, a general framework of an efficient multipledescription robust communication system with 2- and 4-channel cases is presented with a proposed block-based dc reallocation approach using intrinsic correlation. The peak signal-to-noise ratio (PSNR), mean squared error (MSE), bit rate, and entropy are calculated with the proposed method to analyze the reconstruction quality and the calculated results are compared with those of the other MDC methods. It is found that the proposed method, which uses an intrinsic correlation, gives comprehensive improvements over the other recently developed methods.
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