Many of the video streaming applications in today's Internet involve the distribution of content from a CDN source to a large population of interested clients. However, widespread support of IP multicast is unavai...
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ISBN:
(纸本)9781479960361
Many of the video streaming applications in today's Internet involve the distribution of content from a CDN source to a large population of interested clients. However, widespread support of IP multicast is unavailable due to technical and economical reasons, leaving the floor to application layer multicast which introduces excessive delays for the clients and increased traffic load for the network. This paper is concerned with the introduction of an SDN-based framework that allows the network controller to not only deploy IP multicast between a source and subscribers, but also control, via a simple northbound interface, the distributed set of sources where multiple-description coded (MDC) video content is available. We observe that for medium to heavy network loads, relative to the state-of-the-art, the SDN-based streaming multicast video framework increases the PSNR of the received video significantly, from a level that is practically unwatchable to one that has good quality.
Based on compressed sensing (CS), a new multiple description coding method (CS-MDC) was presented. The new method is robust to packet loss or bit error, and has the advantages of simple structure and easy implementati...
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Based on compressed sensing (CS), a new multiple description coding method (CS-MDC) was presented. The new method is robust to packet loss or bit error, and has the advantages of simple structure and easy implementation. The method partitioned an-image into several blocks by interleaving extracting in the wavelet domain, and made random measurements of the image blocks, and then formed multipledescriptions after quantizing and packing. At the decoding end, it reconstructed the original image approximately or exactly with the received bit streams by solving an optimization problem. The proposed method can construct more descriptions with lower complexity because the process of random measuring is simple and easy to realize. Experimental results show that the proposed method exhibits its superiority over SPIHT-MDC with the same packet loss probability, and it can easily generate more descriptions.
This paper presents a quality evaluation of three-dimensional Colour-plus-Depth videos over error prone IP networks and illustrates an overall cloud architecture in which such an evaluation platform may reside. For ac...
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ISBN:
(纸本)9781479957255
This paper presents a quality evaluation of three-dimensional Colour-plus-Depth videos over error prone IP networks and illustrates an overall cloud architecture in which such an evaluation platform may reside. For achieving video transmission both scalable and multiple-descriptioncoding techniques are utilized. On evaluating the impact of packet loss to the perceived 3D video quality, asymmetric packet loss was used for characterizing path diversity. Mean Opinion Score (MOS) for the multipledescription scheme is affected by both the encoding parameters and the sensed packet loss rate at each 3D description. The effect of 3D video reconstruction through interpolation using a single yet reliably delivered description was compared against using the overall number of delivered descriptions. Throughout this experiment it was found that almost all subjects tend to rate the first group of reconstructed 3D videos with higher scores when the network delivery mechanism undergoes severe packet loss rate conditions.
As consumer-level cameras are becoming cheaper and cheaper, the scene of interest can now be captured by multiple cameras simultaneously from different viewpoints. By transmitting texture and depth maps of the views c...
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ISBN:
(纸本)9781479923588
As consumer-level cameras are becoming cheaper and cheaper, the scene of interest can now be captured by multiple cameras simultaneously from different viewpoints. By transmitting texture and depth maps of the views captured using two adjacent cameras, users can synthesize any view in between using depth image based rendering (DIBR) technique such as 3D-warping. This provides users with continuous view angles and is key technique for Free Viewpoint TV (FTV), etc. In this scenario, multiple views must be delivered through bandwidth-limited wireless networks, how to adaptive reduce the source coding rate to fit the bandwidth becomes an important issue. The standard multi-view video codec H.264 MVC explores the inter-view and intra-view correlation to reduce source encoding rate. But all views are required at the client side for decoding any single view, which is apparently not transmission efficient. A better solution is using H.264 to differentially encode the two adjacent views separately, but still this requires double-folder bandwidth comparing to the traditional video streaming. multiple description coding (MDC) encodes one view into multipledescriptions for robust transmission. This inspires another option: sending only part of each view. This can greatly reduce the source encoding rate, but interpolating skipped frames before synthesizing the middle view consumes mobile devices' precious battery life. Whether to send at a lower source encoding rate but with extra energy consumption or send at a high source encoding rate is non-trivial, and has not been studied in any formal way. In this paper, we investigated both source encoding rate reduction and energy consumption with the bandwidth constraint. We formulated the problem into an optimization problem, i.e., maximizing the system utility, which is defined as the received video quality minus the weighted energy consumption. Simulation results showed that our proposed scheme provides a significant advantage over
This paper studies the quality evaluation of three-dimensional colour-plus depth videos over error prone IP networks. Scalable and multiple-descriptioncoding techniques are utilized for transmission. In order to stud...
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ISBN:
(纸本)9781479947584
This paper studies the quality evaluation of three-dimensional colour-plus depth videos over error prone IP networks. Scalable and multiple-descriptioncoding techniques are utilized for transmission. In order to study the impact of packet losses to the perceived 3D video quality, path diversity is characterized by asymmetric packet losses. Mean Opinion Score (MOS) for the multipledescription scheme is affected by both the encoding parameters and the sensed packet loss rate at each 3D description. Moreover, the effect of 3D video reconstruction through interpolation using a single, reliably delivered description has been compared against using all delivered descriptions, and it is found out that subject's rate the 3D videos reconstructed using a single descriptions higher scores under severe packet loss rate conditions.
Peer-to-peer streaming is a well-known technology for the large-scale distribution of audio/video contents. Its widespread adoption derives from the possibility of having a good scalability without the need for the de...
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ISBN:
(纸本)9781479962488
Peer-to-peer streaming is a well-known technology for the large-scale distribution of audio/video contents. Its widespread adoption derives from the possibility of having a good scalability without the need for the deployment of expensive infrastructures such as Content Delivery Networks (CDNs). We think real-time streaming of lessons could open new interesting opportunities in e-learning systems by encouraging interactivity between teachers and learners. Delay requirements are very strict in interactive e-learning scenarios, where playback lag between the event in the real world and the received audio/video should not exceed a few seconds. Only a very short delay would allow students to ask questions during the lesson. At the same time, playback continuity is a key aspect too, since holes in the stream reproduction could seriously compromise the understanding of lectures. In this paper we compared some solutions that try to overcome the limitations of traditional mesh-based P2P systems, which are usually affected by long and unpredictable delays. We finally tried to outline which of the analyzed solutions appears the most suitable one to meet e-learning requirements.
This paper studies how to reconstruct pictures with the best possible quality upon receiving more than one description at the decoder side of a multiple description coding (MDC) system, assuming that an MDC encoder ha...
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This paper studies how to reconstruct pictures with the best possible quality upon receiving more than one description at the decoder side of a multiple description coding (MDC) system, assuming that an MDC encoder has been fixed at the encoder side to generate multipledescriptions. To this end, we formulate the problem into a total variation (TV) regularized optimization in which all received descriptions are regarded as targets to form multiple fidelity terms. Two solutions are then developed. First, we solve a standard Lagrange-type optimization involving multiple Lagrange multipliers, and this approach is applicable to any MDC encoder. Second, when multiple quantizers with different step-sizes or dead-zones are used to generate individual descriptions, we make use of the intersection of the overlapped quantization intervals (in the transform domain) in all received descriptions. Both solutions are demonstrated to offer a quality gain (subjective as well as objective) over what can be achieved in the existing methods. In particular, the second approach is found to offer the best gain consistently when a large number of descriptions are needed. (C) 2011 Elsevier B.V. All rights reserved.
In this paper, we incorporate Trellis Coded Quantization (TCQ) into a two-stage multiple description coding structure to obtain granular gain over two-stage multipledescription Scalar Quantizer (SQ). Analysis and exp...
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In this paper, we incorporate Trellis Coded Quantization (TCQ) into a two-stage multiple description coding structure to obtain granular gain over two-stage multipledescription Scalar Quantizer (SQ). Analysis and experiment on Gaussian signal show that the performance of the proposed scheme can achieve larger gain than that of the two-stage SQ scheme because of better performance of TCQ. The proposed scheme for image coding is shown to be more effective than other relevant multipledescription image coding schemes in terms of central-side-distortion rate performance.
As one of the focus areas of robust video coding and transmission, multipledescription video coding has attracted comprehensive attention. The low coding efficiency of multipledescription video coding is always the ...
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As one of the focus areas of robust video coding and transmission, multipledescription video coding has attracted comprehensive attention. The low coding efficiency of multipledescription video coding is always the major challenge in this field. In order to improve the performance of multipledescription 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%.
The objective of multiple description coding (MDC) is to solve the problem of unreliable channels by means of independent descriptions. This paper proposes an efficient two-description image coding scheme in the wavel...
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ISBN:
(纸本)9781424441303
The objective of multiple description coding (MDC) is to solve the problem of unreliable channels by means of independent descriptions. This paper proposes an efficient two-description image coding scheme in the wavelet domain. Here, the two-layered MDC method is adopted. First, we partition the low-frequency wavelet coefficients into two groups, and pairwise correlating transform (PCT) was applied on 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 subbands by adaptive down-sampling. And finally we use the Wavelet Domain Interpolation for tree Reconstruction (WDIR) to conceal coefficients loss in spatial orientation tree of wavelet when one enhanced description lost during transmission. Experimental results demonstrate that the proposed MDC scheme can achieve good coding performance.
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