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185
EvalVid - A Framework for Video Transmission and Quality Evaluation
- In Proc. of the 13th International Conference on Modelling Techniques and Tools for Computer Performance Evaluation
, 2003
"... With EvalVid we present a complete framework and tool-set for evaluation of the quality of video transmitted over a real or simulated communication network. Besides measuring QoS parameters of the underlying network, like loss rates, delays, and jitter, we support also a subjective video quali ..."
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Cited by 161 (2 self)
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With EvalVid we present a complete framework and tool-set for evaluation of the quality of video transmitted over a real or simulated communication network. Besides measuring QoS parameters of the underlying network, like loss rates, delays, and jitter, we support also a subjective video quality evaluation of the received video based on the frame-by-frame PSNR calculation. The tool-set has a modular construction, making it possible to exchange both the network and the codec. We present here its application for MPEG-4 as example. EvalVid is targeted for researchers who want to evaluate their network designs or setups in terms of user perceived video quality. The tool-set is publicly available [11].
Quality-Adaptive Media Streaming by Priority Drop
- Proc. 13th International Workshop on Network and Operating Systems Support for Digital Audio and Video (NOSSDAV 2003
, 2003
"... This paper presents a general design strategy for streaming media applications in best effort computing and networking environments. Our target application is video on demand using personal computers and the Internet. In this scenario, where resource reservations and admission control mechanisms are ..."
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Cited by 62 (7 self)
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This paper presents a general design strategy for streaming media applications in best effort computing and networking environments. Our target application is video on demand using personal computers and the Internet. In this scenario, where resource reservations and admission control mechanisms are not generally available, effective streaming must be able to adapt in a responsive and graceful manner. The design strategy we propose is based on a single simple idea, priority data dropping, or priority drop for short. We evaluate the efficacy of priority drop as an adaptation tool in the video and networking domains. We show how common video compression formats can be extended to support priority drop, thereby becoming streaming friendly. In particular, we demonstrate that priority-drop video allows adaptation over a wide range of rates and with fine granularity, and the adaptation is tailorable through declarative adaptationpolicy specifications. Our technical contribution with respect to video is to show how to express adaptation policies and how to do priority-mapping, an automatic translation from adaptation policies to priority assignments on the basic units of video. For the networking domain, we present priority-progress streaming, a real-time best-effort streaming protocol. We have implemented and released a prototype video streaming system that incorporates prioritydrop video, priority mapping, and priority-progress streaming. The system has the following advantages: it maintains timeliness of the stream in the face of rate fluctuations in the network, it attempts to utilize available bandwidth fully so as to maximize the average video quality, it starts video display quickly after the user initiates the stream, and it limits the number of quality changes that occur. In summary, we will show that priority-drop is very effective: a single video source can be streamed across a wide range of network bandwidths, on networks saturated with competing
Layered coding vs. multiple descriptions for video streaming over multiple paths
- In Proc. of ACM Multimedia
, 2003
"... In this paper, we examine the performance of specific implementations of multiple description coding and of layered coding for video streaming over error-prone packet switched networks. We compare their performance using different transmission schemes with and without network path diversity. It is s ..."
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Cited by 54 (0 self)
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In this paper, we examine the performance of specific implementations of multiple description coding and of layered coding for video streaming over error-prone packet switched networks. We compare their performance using different transmission schemes with and without network path diversity. It is shown that given the specific implementations there is a large variation in relative performance between multiple description coding and layered coding depending on the employed transmission scheme. For scenarios where the packet transmission schedules can be optimized in a ratedistortion sense, layered coding provides a better performance. The converse is true for scenarios where the packet schedules are not rate-distortion optimized.
The Case for Streaming Multimedia with TCP
- In 8th International Workshop on Interactive Distributed Multimedia Systems (iDMS 2001
, 2001
"... In this paper, we revisit and challenge the dogma that TCP is an undesirable choice for streaming multimedia, video in particular. For some time, the common view held that neither TCP nor UDP, the Internet's main transport protocols, are adequate for video applications. UDP's service model ..."
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Cited by 43 (5 self)
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In this paper, we revisit and challenge the dogma that TCP is an undesirable choice for streaming multimedia, video in particular. For some time, the common view held that neither TCP nor UDP, the Internet's main transport protocols, are adequate for video applications. UDP's service model doesn't provide enough support to the application while TCP's provides too much. Consequently, numerous research works proposed new transport protocols with alternate service-models as more suitable for video. For example, such service models might provide higher reliability than UDP but not the full-reliability of TCP. More recently, study of Internet dynamics has shown that TCP's stature as the predominant protocol persists. Through some combination of accident and design, TCP's congestion avoidance mechanism seems essential to the Internet's scalability and stability. Research on modeling TCP dynamics in order to e#ectively define the notion of TCP-friendly congestion avoidance is very active. Meanwhile, proposals for video-oriented transport protocols continue to appear, but they now generally include TCPfriendly congestion avoidance. Our concern is over the marginal benefit of changing TCP's service model, given the presence of congestion avoidance. As a position paper, our contribution will not be in the form of final answers, but our hope is to convince the reader of the merit in reexamining the question: do applications need a replacement for TCP in order to do streaming video? 1
Segmentation of Moving Objects in Video Sequences
, 2001
"... various content-based functionalities for multimedia applications. To support such functionalities, as well as to improve coding efficiency, MPEG-4 relies on a decomposition of each frame of an image sequence into video object planes (VOPs). Each VOP corresponds to a single moving object in the scen ..."
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Cited by 41 (0 self)
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various content-based functionalities for multimedia applications. To support such functionalities, as well as to improve coding efficiency, MPEG-4 relies on a decomposition of each frame of an image sequence into video object planes (VOPs). Each VOP corresponds to a single moving object in the scene. This paper presents a new method for automatic segmentation of moving objects in image sequences for VOP extraction. We formulate the problem as graph labeling over a region adjacency graph (RAG), based on motion information. The label field is modeled as a Markov random field (MRF). An initial spatial partition of each frame is obtained by a fast, floating-point based implementation of the watershed algorithm. The motion of each region is estimated by hierarchical region matching. To avoid inaccuracies in occlusion areas, a novel motion validation scheme is presented. A dynamic memory, based on object tracking, is incorporated into the segmentation process to maintain temporal coherence of the segmentation. Finally, a labeling is obtained by maximization of the a posteriori probability of the MRF using motion information, spatial information and the memory. The optimization is carried out by highest confidence first (HCF). Experimental results for several video sequences demonstrate the effectiveness of the proposed approach. Index Terms—Markov random fields, MPEG-4, video segmentation, VOP extraction, watershed segmentation. I.
Three-Dimensional Wavelet Coding of Video with Global Motion Compensation
, 1999
"... Three-dimensional (2D+T) wavelet coding of video using SPIHT has been shown to outperform standard predictive video coders on complex high-motion sequences, and is competitive with standard predictive video coders on simple low-motion sequences. However, on a number of typical moderate-motion seq ..."
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Cited by 37 (8 self)
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Three-dimensional (2D+T) wavelet coding of video using SPIHT has been shown to outperform standard predictive video coders on complex high-motion sequences, and is competitive with standard predictive video coders on simple low-motion sequences. However, on a number of typical moderate-motion sequences characterized by largely rigid motions, 3D SPIHT performs several dB worse than motion-compensated predictive coders, because it is does not take advantage of the real physical motion underlying the scene. In this paper, we introduce global motion compensation for 3D subband video coders, and find .5--2 dB gain on sequences with dominant background motion. Our approach is a hybrid of video coding based on sprites, or mosaics, and subband coding. 1 Introduction Motion compensated predictive video coders have been highly successful since their introduction in the '70s. Today they are quickly being deployed commercially in the form of the standards H.261/3 and MPEG-1/2/4. However...
Reconfigurable Instruction Set Processors: A survey
- IEEE Transactions on Software Engineering
, 2000
"... Future interactive multimedia applications are characterized by a large variety of compression algorithms with highly parallel nested loops. It will not be efficient to design custom processors suitable for this wide range of applications due to the uncertainty on what is going to be executed. Inste ..."
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Cited by 31 (3 self)
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Future interactive multimedia applications are characterized by a large variety of compression algorithms with highly parallel nested loops. It will not be efficient to design custom processors suitable for this wide range of applications due to the uncertainty on what is going to be executed. Instead, we must find ways to cope with such dynamic and compute intensive tasks. Reconfigurable instruction set processors can cope with this dynamism by specializing the hardware to the algorithm at hand at runtime. They achieve this thanks to a flexible fabric of coarse-grained processing elements that can be reconfigured to perform different complex algorithms. This paper analyzes the performance improvements obtained by such programmable structures and discusses some of the critical issues, such as reconfiguration times. 1
Scalable internet video using MPEG-4
- Signal Processing: Image Communication
, 1999
"... Real-time streaming of audio-visual content over Internet Protocol (IP) based networks has enabled a wide range of multimedia applications. An Internet streaming solution has to provide real-time delivery and presentation of a continuous media content while compensating for the lack of Quality-of-Se ..."
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Cited by 23 (2 self)
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Real-time streaming of audio-visual content over Internet Protocol (IP) based networks has enabled a wide range of multimedia applications. An Internet streaming solution has to provide real-time delivery and presentation of a continuous media content while compensating for the lack of Quality-of-Service (QoS) guarantees over the Internet. Due to the variation and unpredictability of bandwidth and other performance parameters (e.g. packet loss rate) over IP networks, in general, most of the proposed streaming solutions are based on some type of a data loss handling method and a layered video coding scheme. In this paper, we describe a real-time streaming solution suitable for non-delay-sensitive video applications such as video-on-demand and live TV viewing. The main aspects of our proposed streaming solution are: 1. An MPEG-4 based scalable video coding method using both a prediction-based base layer and a "ne-granular enhancement layer; 2. An integrated transport-decoder bu!er model with priority re-transmission for the recovery of lost packets, and continuous decoding and presentation of video. In addition to describing the above two aspects of our system, we also give an overview of a recent activity within MPEG-4 video on the development of a "ne-granular-scalability coding tool for streaming applications. Results for the performance of our scalable video coding scheme and the re-transmission mechanism are also presented. The latter results are based on actual testing conducted over Internet sessions used for streaming MPEG-4 video in realtime.
Utilitybased network adaptation for mpeg-4 systems
- in Proc. of NOSSDAV, Basking
, 1999
"... Abstract — In this paper, we present the design, implementation and evaluation of a utility-based network adaptation system for the delivery of MPEG-4 video over time-varying networks such as wireless networks. The system comprises a number of algorithms that can be programmed to support application ..."
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Cited by 17 (4 self)
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Abstract — In this paper, we present the design, implementation and evaluation of a utility-based network adaptation system for the delivery of MPEG-4 video over time-varying networks such as wireless networks. The system comprises a number of algorithms that can be programmed to support application-specific adaptation in the network or at its edges. By exploiting video content and user preferences, an online utility generator can dynamically formulate bandwidth utility functions and scaling profiles that capture applicationspecific adaptation. The utility generator employs a video content classification algorithm to speedup processing and an adaptive prediction algorithm to keep dynamically generated utility functions meaningful over network adaptation timescales. Network adaptation is based on a utility-fair bandwidth renegotiation algorithm that realizes profile-based media scaling. The signaling system efficiently delivers utility functions and scaling profiles to network adaptation agents.
