In this paper, a comparison of a scalable multiple description coding (MDC) scheme and the forward error correction (FEC) coding using Raptor code for the scalable extension of H.264/AVC (SVC) is presented. Unequal an...
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ISBN:
(纸本)9781467345729
In this paper, a comparison of a scalable multiple description coding (MDC) scheme and the forward error correction (FEC) coding using Raptor code for the scalable extension of H.264/AVC (SVC) is presented. Unequal and equal protection of the base and enhancement layer with different amount of redundancy at the average burst lengths of 2, 5 and 20 are considered. The experimental results show that scalable MDC is generally preferable at the low redundancy rate and long average burst length, while FEC using Raptor code is favorite in case of high redundancy rate and the channel with short average burst length for the resilient delivery of scalable video.
The error free communication of video data over multi-hop wireless networks is a challenging research problem. multiple description coding has been proposed as a possible solution to leverage path diversity for error ...
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ISBN:
(纸本)9781467300469
The error free communication of video data over multi-hop wireless networks is a challenging research problem. multiple description coding has been proposed as a possible solution to leverage path diversity for error robustness. Forward error correction is an additional protection that can be provided to each description. Random linear codes have had renewed interest fostered by the multi-hop and multi-interface radio receivers. In this study, the descriptions are created using the encoding features of slicing and data partitioning for H.264/AVC video. The unequally protected video is protected with Expanding window-Random linear codes against channel errors. Fading channel error model is used to simulate real-world wireless channels. We also propose an adaptive scheme for video transmission over multiple paths. Such scheme may adapt to the varying channel conditions as is frequently the case in wireless transmission. The results show that the proposed scheme can be used for emerging wireless standards.
Federated learning (FL) generally suffers significant communication overhead from high-traffic gradient synchronization. The majority of existing studies on this problem aim at compressing gradients under the premise ...
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ISBN:
(纸本)9798350390155;9798350390162
Federated learning (FL) generally suffers significant communication overhead from high-traffic gradient synchronization. The majority of existing studies on this problem aim at compressing gradients under the premise of reliable transmission. While transmission reliability can be ensured via TCP by default, the notably increased latency and retransmitted packets are prohibitive for most clients in FL. To tackle this issue, we propose FedMDC, a retransmission-free compression framework for FL over packet lossy networks. Given clients' limited resources, FedMDC adopts multiple description coding to encode gradients into redundant descriptions for erasure resilience simply through multiplying an overcomplete matrix;and then quantizes these descriptions for compression. To further reduce quantization distortion and computational overhead, a reduced decoding algorithm is developed by decoding the aggregation of all clients' encodings in conjunction with a customized dither quantization design. Besides, FedMDC explicitly supports adaptive bitrates subject to clients' heterogeneous communication budgets, which maximize resource utilization to facilitate distortion reduction and accelerate model convergence. Theoretical analysis and experimental results both demonstrate the effectiveness of our scheme.
In this paper, we propose a novel multiple description coding method based on the Wyner-Ziv scheme for robust video transmission. In the proposed method, the motion vector (MV) field is encoded into two descriptions, ...
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ISBN:
(纸本)9781728123929
In this paper, we propose a novel multiple description coding method based on the Wyner-Ziv scheme for robust video transmission. In the proposed method, the motion vector (MV) field is encoded into two descriptions, which are transmitted over different paths to the decoder. Unlike the conventional methods, the correlation between descriptions in the proposed method is generated without using any additional redundant data since it can be estimated based on the high spatial correlation of MVs themselves in the MV field. At the decoder, this correlation is then employed as the side information in the Wyner-Ziv scheme to effectively improve the performance of the proposed method. Experimental results show that the proposed method can achieve a wide range of tradeoffs between coding efficiency and error resilience, and provide much better objective and subjective performance than other conventional MDC methods.
Broadband Internet access using ADSL or cable modems provides sufficient bandwidth for real-time video streaming. If television channels could be distributed on the Internet, each channel would get a world wide audien...
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ISBN:
(纸本)0780385667
Broadband Internet access using ADSL or cable modems provides sufficient bandwidth for real-time video streaming. If television channels could be distributed on the Internet, each channel would get a world wide audience. However television distribution from a single server does not scale and IP-level multicasting is complex and costly. We propose a solution based on application-level multicasting using a P2P network, called P2P-TV. Each peer receives a video stream and must also forward this stream to others. This paper presents an architecture for streaming video. Our P2P-TV proposal aims to solve three problems that are currently not addressed in other P2P streaming proposals, namely 1) maximizing the usage of all available peer bandwidth, 2) taking current network conditions into account (network awareness), and 3) the Freeriding problem. multiple description coding is an integral part of our solution. By splitting the video stream into smaller streams we can utilize all the bandwidth of a peer multiple streams allow more efficient adaptation of the multicast tree to current network conditions. Bittorrent-like bartering of content is also enabled by using multiple streams.
An analysis-based approach for unequal loss-protected multiple description coding (packetization) of the scalable (prioritized / progressive) source code streams is proposed. For a given number of packets (description...
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ISBN:
(纸本)9781424456536
An analysis-based approach for unequal loss-protected multiple description coding (packetization) of the scalable (prioritized / progressive) source code streams is proposed. For a given number of packets (descriptions) of the known size, unequal loss-protected packetization leads to segment the scalable code stream, such that the source can be reconstructed with the maximum possible fidelity at the decoder side. Here, we find an analytical relation between optimal sizes of any two consecutive segments. This idea yields a low-complexity progressive solution with a performance close to that of local search [1], which has been approved as an efficient method to solve the segmentation problem. Simulation results are used to confirm the efficiency of the proposed method as compared with the local search algorithm.
Layered coding (LC) and multiple description coding (MDC) have been proposed as two different kinds of "quality adaptation" schemes for video delivery over the current Internet or wireless networks. To combi...
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ISBN:
(纸本)0819448222
Layered coding (LC) and multiple description coding (MDC) have been proposed as two different kinds of "quality adaptation" schemes for video delivery over the current Internet or wireless networks. To combine the advantages of LC and MDC, we present a new approach - multipledescription Layered coding (MDLC), to provide reliable video communication over a wider range of network scenarios and application requirements. MDLC improves LC in that it introduces redundancy in each layer so that the chance of receiving at least one description of base layer is greatly enhanced. Though LC and MDC are each good in limit cases (e.g., long end-to-end delay for LC vs. short delay for MDC), the proposed MDLC system can address intermediate cases as well. Same as a LC system with retransmission, the MDLC system can have a feedback channel to indicate which descriptions have been correctly received. Thus a low redundancy MDLC system can be implemented with our proposed runtime packet scheduling system based on the feedback information. The goal of our scheduling algorithm is to find a proper on-line packet scheduling policy to maximize the playback quality at the decoder. Previous work on scheduling algorithms has not considered multiple decoding choices due to the redundancy between data units, because of the increase in complexity involved in considering alternate decoding paths. In this paper, we introduce a new model of Directed Acyclic HyperGraph (DAHG) to represent the data dependencies among frames and layers, as well as the data correlation between descriptions. The impact of each data unit to others is represented by messages passing along the graph with updates based on new information received. Experimental results show that the proposed system provides more robust and efficient video communication for real-time applications over lossy packet networks.
multiple description coding (MDC) is a technique where multiple streams from a source are generated, each individually decodable and mutually refinable. In this paper, a new Mixed Layer MDC (MLMDC) scheme is presented...
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ISBN:
(纸本)9781612843490
multiple description coding (MDC) is a technique where multiple streams from a source are generated, each individually decodable and mutually refinable. In this paper, a new Mixed Layer MDC (MLMDC) scheme is presented which achieves a higher side quality compared to conventional MDCs. The improved side performance leads to higher average video quality at the receiver in lossy networks. For each DCT coefficient, we generate two coefficients: Base Coefficient (BC) and Enhancement Coefficient (EC) which are combined together. When all descriptions are available, they are decomposed and decoded to achieve high quality video. When one description is not available, we use estimation to extract as much of the BC as possible from the received description. The algorithm is implemented in JM16.0 and its performance for two-description and four-descriptioncoding is verified by experiments.
multiple description coding has been studied as an approach for transmission of images over error Prone environments. The multiple description coding method proposed here takes into account the content of the image an...
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ISBN:
(纸本)076951507X
multiple description coding has been studied as an approach for transmission of images over error Prone environments. The multiple description coding method proposed here takes into account the content of the image and provides the least amount of degradation, caused by loss of descriptors, for those areas of the image which are of greater interest. This is achieved by employing a non-linear geometrical transform to odd redundancy mainly to the area of interest followed by a partitioning of the nonlinearly transformed image into sub-images which are coded and transmitted over separate channels, Simulations show that this approach yields exceptional performance even when only one descriptor is received. Moreover, the method proposed here can be implemented through pre- and post-processing of the image data, without modification to the source codecs (e.g., JPEG).
We derive a single-letter lower bound on the minimum sum rate of multiple description coding with symmetric distortion constraints. For the binary uniform source with the Hamming distortion measure, this lower bound c...
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ISBN:
(纸本)9781479913213
We derive a single-letter lower bound on the minimum sum rate of multiple description coding with symmetric distortion constraints. For the binary uniform source with the Hamming distortion measure, this lower bound can be evaluated with the aid of a certain minimax theorem. A similar minimax theorem is established in the quadratic Gaussian setting, which is further leveraged to analyze the special case where the minimum sum rate subject to two levels of distortion constraints (with the second level imposed on the complete set of descriptions) is attained;in particular, we determine the minimum achievable distortions at the intermediate levels.
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