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Packet Video Workshop (PV), 2012 19th International

Date 10-11 May 2012

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Displaying Results 1 - 25 of 37
  • Author index

    Page(s): 190 - 192
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    Freely Available from IEEE
  • 2012 19th International Packet Video Workshop [Copyright notice]

    Page(s): 1
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  • [Front cover]

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  • A performance evaluation framework for video streaming

    Page(s): 19 - 24
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (442 KB) |  | HTML iconHTML  

    In this paper, we present a generic framework for performance evaluation of video streams. We embrace the perspective of a streaming application, and model the playback buffer level at given network and playback conditions. That way, our model enables flexible, adaptable evaluation of a wide variety of streaming methods and protocols. We test our model on HTML5 and Flash video as served by the YouTube web site. We find universal achievable limits in any streaming process, and explore quality trade-offs every application has to decide on. View full abstract»

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  • Subjective quality assessment of video conferences and telemeetings

    Page(s): 25 - 30
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (330 KB) |  | HTML iconHTML  

    Videoconferencing has become more popular in recent years. The conference situation can be very complex with several participants using different types of equipment. To ensure a good quality, agreed methods to quantify the subjective quality of telemeetings are needed. The development of such assessment methods is ongoing in ITU-T Study Group 12. This paper describes several subjective tests performed at Ericsson, both one-way and conversational tests. The purpose of these tests was to increase the knowledge on the perceived quality of different telemeeting scenarios and to develop test methodologies for quality evaluation of multiparty conversations. View full abstract»

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  • Seamless and efficient stream switching of multi-perspective videos

    Page(s): 31 - 36
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (407 KB) |  | HTML iconHTML  

    According to Cisco study, mobile video already makes up 50% of mobile data traffic and is expected to reach 66% in 2015. Nowadays, the video watching experience is being made more interactive to enhance the user experience. One way that users can enjoy better watching experience is to be able to switch between different perspectives in one video. Such multi-perspective events require an efficient streaming scheme that is both cost-efficient and user-friendly. Based on three popular video streaming methods (RTP/RTSP, HTTP Progressive Download and DASH), we propose three different solutions for streaming multi-perspective videos. Architectures and principles of each solution are discussed and implemented on an Android-platform-based smartphone. To compare the performance of our solutions, we design a framework for evaluation. The metrics we use to evaluate our solutions include bandwidth consumption and Quality of Service (QoS) parameters, such as switch delay and switch rendering. Our comparison shows that all three solutions can achieve acceptable performance for perspective switching. However, the DASH-based solution outperforms the remaining solutions at it provides shortest delay and seamless switching of perspectives for a given bandwidth. View full abstract»

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  • Compressed domain stitching of HEVC streams for video conferencing applications

    Page(s): 36 - 40
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (258 KB) |  | HTML iconHTML  

    We present a method for compressed domain stitching of streams coded according to the (draft) High Efficiency Video Coding (HEVC) specification for video conferencing applications. The main challenges for mixing of video streams in the compressed domain are elaborated and divided into pixel processing level, the level of syntax elements, and entropy coding level. A special focus is on the mechanisms of intra- and inter-prediction mismatch and the respective countermeasures. We propose a solution for mixing video streams on tile level enabling light-weight video stitching. This includes a novel approach for avoiding mismatch due to temporal prediction. The simulation results show a significant gain in compression efficiency and computational complexity over pixel domain stitching of video content. View full abstract»

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  • Online multipath convolutional coding for real-time transmission

    Page(s): 41 - 46
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (141 KB) |  | HTML iconHTML  

    Most of multipath multimedia streaming proposals use Forward Error Correction (FEC) approach to protect from packet losses. However, FEC does not sustain well burst of losses even when packets from a given FEC block are spread over multiple paths. In this article, we propose an online multipath convolutional coding for real-time multipath streaming based on an on-the-fly coding scheme called Tetrys. We evaluate the benefits brought out by this coding scheme inside an existing FEC multipath load splitting proposal known as Encoded Multipath Streaming (EMS). We demonstrate that Tetrys consistently outperforms FEC in both uniform and burst losses with EMS scheme. We also propose a modification of the standard EMS algorithm that greatly improves the performance in terms of packet recovery. Finally, we analyze different spreading policies of the Tetrys redundancy traffic between available paths and observe that the longer propagation delay path should be preferably used to carry repair packets. View full abstract»

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  • Virtual RTCP: A case study of monitoring and repair for UDP-based IPTV systems

    Page(s): 47 - 52
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (213 KB) |  | HTML iconHTML  

    IPTV systems have seen widespread deployment, but often lack robust mechanisms for monitoring the quality of experience. This makes it difficult for network operators to ensure that their services match the quality of traditional broadcast TV systems, leading to consumer dissatisfaction. We present a case study of virtual RTCP, a new framework for reception quality monitoring and reporting for UDP-encapsulated MPEG video delivered over IP multicast. We show that this allows incremental deployment of reporting infrastructure, coupled with effective retransmission-based packet loss repair. View full abstract»

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  • Mobile video transmission via Wyner-Ziv video coding and rate compatible modulation

    Page(s): 53 - 58
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (214 KB) |  | HTML iconHTML  

    This work refers to mobile video transmission at the physical layer. We develop a video communication system using transform-domain Wyner-Ziv video coding and rate compatible modulation. Because Wyner-Ziv video coding is employed, the encoder and transmitter of this system have low complexity and therefore are applicable to mobile devices. In addition, rate compatible modulation proves more efficient than the conventional adaptive modulation and coding, and thus achieves a significantly higher throughput. This increase of throughput leads to an improvement of the video quality by up to 1.5 dB in PSNR under the same bandwidth constraint and transmission channel state. Above all, the combination of Wyner-Ziv video coding and rate compatible modulation turns out to be a competitive candidate solution for mobile video communication with low encoding complexity. View full abstract»

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  • SDC: Scalable description coding for adaptive streaming media

    Page(s): 59 - 64
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (355 KB) |  | HTML iconHTML  

    Video compression techniques enable adaptive media streaming over heterogeneous links to end-devices. Scalable Video Coding (SVC) and Multiple Description Coding (MDC) represent well-known techniques for video compression with distinct characteristics in terms of bandwidth efficiency and resiliency to packet loss. In this paper, we present Scalable Description Coding (SDC), a technique to compromise the tradeoff between bandwidth efficiency and error resiliency without sacrificing user-perceived quality. Additionally, we propose a scheme that combines network coding and SDC to further improve the error resiliency. SDC yields upwards of 25% bandwidth savings over MDC. Additionally, our scheme features higher quality for longer durations even at high packet loss rates. View full abstract»

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  • Video adaptation proxy for wireless Dynamic Adaptive Streaming over HTTP

    Page(s): 65 - 70
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (437 KB) |  | HTML iconHTML  

    This research studies Dynamic Adaptive Streaming over HTTP (DASH) in cellular broadband access networks (e.g. HSDPA, HSPA+, LTE). We propose a wireless DASH (WiDASH) proxy to enhance the Quality-of-Experience (QoE) of wireless DASH. WiDASH proxy locates at the edge between Internet and wireless core networks. Different from conventional DASH, whose rate adaptation logics are either implemented locally in the user equipment or in the DASH server, WiDASH proxy is in charge of video adaptation, which makes it feasible to perform global optimization over multiple concurrent DASH flows. WiDASH proxy improves DASH QoE by three novel technologies. The first one is architecture level innovation. WiDASH simultaneously explores the potential of both split TCP and parallel TCP. It splits the original TCP connection from DASH server to a wireless user into one wired TCP and multiple wireless TCPs. This approach is able to increase video streams' average throughput without sacrificing inter user fairness. Second, WiDASH proxy employs video quality aware dynamic prioritization. Low bit rate video streams are entitled with high priority to guarantee minimum QoE for users with bad wireless channel quality. A video stream's priority is gradually dropped to normal state with the growth of its bit rate so that inter flow fairness between video streams and background best effort flows are still maintained. Third, we design a multiple-input multiple-output adaptive optimal controller, based on adaptive control theory. This rate controller minimizes a quadratic cost function which is defined as the weighted sum of multiple concurrent DASH videos' distortion, bit rate variation, and playback jitter. The solution of the optimization problem implicitly coordinates multiple DASH streams to improve overall streaming QoE. Simulation results verify that WiDASH proxy is able to improve QoE by providing smoother video streams with higher average visual quality for wireless HTTP video streamin- . View full abstract»

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  • Content aware delivery of visual attention based scalable multi-view video over P2P

    Page(s): 71 - 76
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    3D media applications have become widespread thanks to the intense research being conducted on 3D enabling technologies, commercial products being released and service providers. There is also a huge potential for IP network to become a major means for delivering 3D video services, being highly flexible and allowing much custom and scalable applications to take up. Peer-to-Peer (P2P) video streaming, which offers high scalability in the presence of many media consuming peers, is suitable for multi-view video applications with significantly higher bandwidth requirements. To exploit flexible streaming and also serve a range of displays, P2P networking should be combined with scalable coded multi-view video that offers a useful bit-rate and maximum viewpoint adaptation range. However, since maintaining users' Quality of Experience (QoE) is a primary target, scalable coded video should ensure that perceptually sensible visual data is delivered with high accuracy at all times to users, even under severe network conditions. Hence, content-based visual attention models provide a suitable means for letting salient video data be delivered at all times to users. With the utilization of appropriate adaptation decision making process in users' equipment, the P2P protocol can adaptively stream the scalable 3D media. Work presented in this paper explains such a delivery framework over P2P networks. View full abstract»

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  • Correlation-aware packet scheduling for multi-camera streaming

    Page(s): 77 - 82
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (869 KB) |  | HTML iconHTML  

    In multi-view applications, multiple cameras acquire the same scene from different perspectives, which results in correlated video streams. It becomes important to exploit this correlation at the acquisition side (i.e., in the source coding) or at the receiver side (i.e., during error-concealment). In this work, we propose a correlation-aware scheduling algorithm for multi-camera sets, in which information from all views need to be sent over a bottleneck channel to clients that decode the 3D scene captured by the cameras. Based on a novel rate-distortion model, that takes into account the correlation between sources, we propose a solution that minimizes the distortion in the scene reconstruction and adapts to temporal variations in the scene content. Simulation results show the gain of the scheduling algorithm when the correlation model is known in the optimization, compared to scheduling policies with no information about the correlation or with a priori camera selection algorithms. View full abstract»

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  • Mobile video sensitivity to packet loss and packet delay variation in terms of QoE

    Page(s): 83 - 88
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (549 KB) |  | HTML iconHTML  

    With the growth of the mobile internet, the popularity of multimedia services and applications have increased rapidly. As a result, end-users become quality-conscious. To fulfill the users' expectations, the study of quality of experience (QoE) is becoming very important for both researchers and service providers. This paper analyses the impact on perceived quality of received videos encoded with the H.264 baseline profile, which is suitable for mobile video, and streamed through an emulated network with packet loss and packet delay variation. To evaluate the video QoE, tests are conducted on a mobile device and on a laptop. The users' responses show that the baseline profile of H.264 is very sensitive to packet loss and packet delay variation. Moreover, there is no considerable impact on users' perception either test is conducted on the mobile device or on the laptop by playing the same resolution video. View full abstract»

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  • Distributed rate allocation in P2P networks with inter-session network coding

    Page(s): 89 - 94
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (232 KB) |  | HTML iconHTML  

    In this paper, we propose a distributed rate allocation algorithm for delay minimal data delivery in overlay networks where multiple sources compete simultaneously for the available network resources. In order to efficiently utilize the network resources, we propose to use inter-session network coding. We devise a distributed algorithm that allows peers to determine the optimal coding combinations and the packet rates for each type of combinations to be requested from the parent peers. The rate allocation problem is formulated as a decoding delay minimization problem, where every peer seeks the rates that minimize the average expected delay of the peer and its children peers. To solve this non-convex optimization problem, we introduce the concept of equivalent packet flows, which permits to estimate the expected number of packets that every peer needs to collect for decoding. We then decompose our original rate allocation problem into a set of convex subproblems, which we eventually combine to obtain the solution to the delay minimization problem. The results demonstrate that the proposed scheme eliminates effectively the bottlenecks and reduces the delay time experienced by users with limited resources. View full abstract»

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  • Near-optimal content replication for interactive multiview video streaming

    Page(s): 95 - 100
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (235 KB) |  | HTML iconHTML  

    In interactive multiview video streaming (IMVS), a client can watch the multiview video and interact with it by switching to different viewing angles at frozen moments. To provide scalable IMVS services, a content provider often deploys distributed content servers with heterogeneous storage capacities in order to collaboratively replicate video segments for their clients. IMVS presents a new challenge in content replication: which video segments to replicate to support interactive view-switching during an IMVS session. In this paper, we first formulate the content replication problem as an integer linear programming (ILP) problem, which is proven to be NP-hard. We then propose a fast algorithm to solve it with bounded approximation error. In this algorithm, we first solve the ILP problem as a relaxed LP problem, and then heuristically round the resulting fractional LP solution to integer towards ILP feasibility. Simulation results show that our replication strategy can substantially reduce access costs compared to a commonly used replication scheme and a state-of-the-art replication scheme. View full abstract»

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  • Joint optimization of flow allocation and data center placement in multi-service networks

    Page(s): 101 - 106
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (191 KB) |  | HTML iconHTML  

    We present a framework for jointly optimizing the data center placement and network flow allocation in multi-service networks. The optimization is derived within a cost-performance formulation that aims at minimizing the overall operating cost of the network over which the services are provided, given a set of end-user performance requirements. The problem formulation represents a linear programming that is efficiently solved via a convex optimization technique that we design to this end. The generality of the formulation allows its application to other important problems, such as green networking and transportation of hazardous materials. We introduce the concept of cost performance versus service requirements lower-convex hull that can be employed to study the operational efficiency of various data center location and network flow allocation configuration points. We investigate the performance of the optimization framework via simulation experiments and compare its efficiency against two heuristic reference schemes. We demonstrate substantial operational cost savings or conversely service performance advances, for the same overall operating cost. View full abstract»

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  • Scaling server-based channel-change acceleration to millions of IPTV subscribers

    Page(s): 107 - 112
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (203 KB) |  | HTML iconHTML  

    Channel-change times in multicast-based IPTV distribution networks are often slow compared to analog video networks where the channel change is almost instant. One way to overcome these relatively slower channel change is server-based channel-change acceleration based on the rapid acquisition method standardized by the IETF. Concerns about potentially large backbone traffic and bandwidth requirements, however, have prevented operators from deploying such a solution on a large scale. In this paper, we explain techniques to overcome this limit and present data from a real-life deployment. We show how this solution is deployed in a scalable way to almost a million of IPTV set-top boxes while limiting the required backbone traffic and server capacity. View full abstract»

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  • The effect of multi-generation encoding in broadcast contribution on the end-user video quality

    Page(s): 113 - 118
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1526 KB) |  | HTML iconHTML  

    In this paper, we consider the effect of multi generation encoding in broadcast contribution on the video quality of the end-user. We first discuss the broadcast chain consisting of a contribution link followed by the last mile IPTV MPEG-4/AVC. We then evaluate the suitability of JPEG2000 and MPEG-4/AVC for broadcast contribution in terms of video quality and latency. Furthermore, we discuss the influence of the contribution encoding on the end user emission quality. Our results indicate that JPEG2000 is an excellent solution for high quality contribution at high bit-rates and MPEG-4/AVC provides a complimentary solution to JPEG2000 when there is not enough bit-rate. View full abstract»

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  • Playout adaptation for peer-to-peer streaming systems under churn

    Page(s): 119 - 124
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (164 KB) |  | HTML iconHTML  

    We address the problem of playout adaptation in peer-to-peer streaming systems. We propose two algorithms for playout adaptation: one coordinated and one distributed. The algorithms dynamically adapt the playback delay of the peers so that the playout miss ratio is maintained within a predefined interval. We validate the algorithms and evaluate their performance through simulations under various churn models. We show that playout adaptation is essential in peer-to-peer systems when the system size changes. At the same time, our results show that distributed adaptation performs well only if the peers in the overlay have similar playback delays. Thus, some form of coordination among the peers is necessary for distributed playout adaptation in peer-to-peer streaming systems. View full abstract»

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  • RapidStream: P2P streaming on android

    Page(s): 125 - 130
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (406 KB) |  | HTML iconHTML  

    In this paper we present the architecture of the first mobile P2P streaming prototype for the operating system Android. At first, we discuss the application of P2P streaming in the scenario of mobile networking. Then, the system and software architecture of our prototypical implementation is elaborated. In addition, an initial field test to evaluate the feasibility of the proposed approach is presented. Finally, we report our insights arising from the practical experience with Android. View full abstract»

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  • Wireless video transmission with over-the-air packet mixing

    Page(s): 131 - 136
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    In this paper, we propose a system for wireless video transmission with a wireless physical layer (PHY) that supports cooperative forwarding of interfered/superimposed packets. Our system model considers multiple and independent unicast transmissions between network nodes while a number of them serve as relays of the interfered/superimposed packets. For this new PHY the average transmission rate that each node can achieve is estimated first. Next, we formulate a utility optimization framework for the video transmission problem and we show that it can be simplified due to the features of the new PHY. Simulation results reveal the system operating regions for which superimposing wireless packets is a better choice than a typical cooperative transmission. View full abstract»

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  • Dynamic scaling of VoD services into hybrid clouds with cost minimization and QoS guarantee

    Page(s): 137 - 142
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (257 KB) |  | HTML iconHTML  

    A large-scale video-on-demand (VoD) service demands huge server costs, to provision thousands of videos to millions of users with high streaming quality. As compared to the traditional practice of relying on large on-premise server clusters, the emerging platforms of geo-distributed public clouds promise a more economic solution: their on-demand resource provisioning can constitute ideal supplements of resources from on-premise servers, and effectively support dynamic scaling of the VoD service at different times. Promising though it is, significant technical challenges persist before it turns into reality: how shall the service provider dynamically replicate videos and dispatch user requests over the hybrid platform, such that the service quality and the minimization of overall cost can be guaranteed over the long run of the system? In this paper, we present a dynamic algorithm that optimally makes decisions on video replication and user request dispatching in a hybrid cloud of on-premise servers and geo-distributed cloud data centers, based on the Lyapunov optimization framework. We rigorously prove that this algorithm can nicely bound the streaming delays within the preset QoS target in cases of arbitrary request arrival patterns, and guarantee that the overall cost is within a small constant gap from the optimum achieved by a T-slot lookahead mechanism with known information into the future. We evaluate our algorithm with extensive simulations under realistic settings, and demonstrate that cost minimization and smooth playback can be achieved in cases of volatile user demands. View full abstract»

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  • Spatial and temporal prediction scheme for 3D holoscopic video coding based on H.264/AVC

    Page(s): 143 - 148
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1043 KB) |  | HTML iconHTML  

    Holoscopic imaging, also referred to as integral imaging, is an advantageous solution for glassless 3D which promises in the future to change the market for 3D video systems. In order to efficiently transmit this type of 3D video content over current and emerging networks, this paper proposes an improved spatial and temporal prediction scheme which attempts to exploit the particular spatial self-similarity of this type of content, as well as the high temporal correlation between successive frames, in order to achieve a better prediction and, consequently, improve the coding performance. Initially, this paper provides a brief presentation of the general concepts behind holoscopic imaging with special attention to the spatial correlations, which are inherent to this type of content, due to the micro-lens array used both for acquisition and display. This acquisition process generates a planar intensity distribution behind the micro-lens array that contains an array of micro-images in which a different perspective of the scene is shown. These micro-images exhibit a high correlation between them, which can be seen as a form of self-similarity within the holoscopic image. Experimental results based on a modified H.264/AVC video codec that can handle 3D holoscopic self-similarity estimation and compensation are presented and clearly show advantages over H.264/AVC, in terms of coding efficiency of using the proposed approach for full parallax 3D holoscopic content. View full abstract»

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