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Video quality

About: Video quality is a research topic. Over the lifetime, 13143 publications have been published within this topic receiving 178307 citations.


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Journal ArticleDOI
TL;DR: This work proves that the formulated problem is NP-hard and proposes an optimal, two-step dynamic programming solution with pseudo-polynomial time complexity, which offers significant improvement on the video quality over a naive algorithm and an adapted greedy algorithm.
Abstract: Future mobile broadband networks are characterized with high data rate and improved coverage, which will enable real-time video multicast and broadcast services. Scalable video coding (SVC), combined with adaptive modulation and coding schemes (MCS) and wireless multicast, provides an excellent solution for streaming video to heterogeneous wireless devices. By choosing different MCSs for different video layers, SVC can provide good video quality to users in good channel conditions while maintaining basic video quality for users in bad channel conditions. A key issue to apply SVC to wireless multicast streaming is to choose appropriate MCS for each video layer and to determine the optimal resource allocation among multiple video sessions. We formulate this problem as total utility maximization, subject to the constraint of available radio resources. We prove that the formulated problem is NP-hard and propose an optimal, two-step dynamic programming solution with pseudo-polynomial time complexity. Simulation results show that our algorithm offers significant improvement on the video quality over a naive algorithm and an adapted greedy algorithm, especially in the scenarios with multiple real video sequences and limited radio resources.

79 citations

Proceedings ArticleDOI
19 Sep 2011
TL;DR: A novel joint-source channel code, that allows the sender to continuously transmit video bits, and the receiver to decode a video quality corresponding to the number of bits it receives and the instantaneous wireless channel quality, that outperforms state of the art graceful video delivery systems by nearly 6dB PSNR.
Abstract: Video streaming performance on wireless networks is choppy. The culprit is the unpredictable wireless medium, whose fluctuations results in fluctuating throughput and bit errors. Current video codecs are not equipped to handle such variations since they exhibit an all or nothing behavior. If the channel is strong and above a threshold, the video stream gets decoded perfectly. If not, typically nothing gets decoded. Thus, there is no graceful degradation with wireless conditions. In this paper, we present a new technique FlexCast, that delivers a video reconstruction whose quality automatically varies with the channel conditions. The key idea is a novel joint-source channel code, that allows the sender to continuously transmit video bits, and the receiver to decode a video quality corresponding to the number of bits it receives and the instantaneous wireless channel quality. We show via experimental evaluation that name performs almost as well as the optimal scheme, and outperforms the state of the art graceful video delivery systems by nearly 6dB PSNR.

79 citations

Book ChapterDOI
01 Jan 1997
TL;DR: A method of QoS mapping between user’s preference on video quality and a required bandwidth to transport the video across the network and the mapping method is investigated, which is quantified by MOS (Mean Opinion Score) evaluation.
Abstract: In this paper, we present a method of QoS mapping between user’s preference on video quality and a required bandwidth to transport the video across the network. We first investigate the mapping method from QoS parameters to the required bandwidth on the network. For this purpose, we assume that the underlying network supports some bandwidth allocation mechanism, such as DBR service class in ATM, RSVP, IPv6 and so on. Then, for given QoS parameters in terms of spatial, SNR, and timely resolutions, the required bandwidth to support the MPEG-2 video transmission is determined by analyzing the traced MPEG-2 streams. We next consider the mapping method between QoS parameters and the user’s perceived video quality, which is quantified by MOS (Mean Opinion Score) evaluation. Based on the above results, we discuss a systematic method to estimate the required bandwidth to guarantee user’s preference on video quality.

79 citations

Journal ArticleDOI
TL;DR: The proposed spatiotemporal pattern-based approach outperforms the state-of-the-art approaches in terms of mean average precision (MAP) and normalized detection cost rate (NDCR) on the testing datasets and can achieve high quality of near-duplicate video localization.
Abstract: With the exponential growth of web multimedia contents, the Internet is rife with near-duplicate videos, the video copies applied with visual/temporal transformations and/or post productions. Two critical issues, copyright infringement and search result redundancy, arise accordingly. To resolve these problems, this paper proposes a spatiotemporal pattern-based approach under the hierarchical filter-and-refine framework for efficient and effective near-duplicate video retrieval and localization . Firstly, non-near-duplicate videos are fast filtered out through a computationally efficient data structure, termed pattern -based index tree (PI-tree). Then, an m- pattern -based dynamic programming (mPDP) algorithm is designed to localize near-duplicate segments and to re-rank the videos retrieved. The influence of time shift misalignment can be alleviated by time-shift m-pattern similarity (TPS) measurement. Comprehensive experiments on the five datasets are conducted to verify the effectiveness, efficiency, robustness, and scalability of the proposed approach. Convincing results demonstrate that our proposed approach outperforms the state-of-the-art approaches in terms of mean average precision (MAP) and normalized detection cost rate (NDCR) on the testing datasets. Furthermore, the proposed approach can achieve high quality of near-duplicate video localization in terms of quality frames (QF) and mean F1.

79 citations

Proceedings ArticleDOI
11 Nov 2005
TL;DR: A rate-distortion model which predicts end-to-end video quality in throughput limited environments is presented and used to determine the over-provisioning necessary to avoid self-inflicted congestion.
Abstract: We study peer-to-peer multicast streaming, where a source distributes real-time video to a large population of hosts by making use of their forwarding capacity rather than relying on dedicated media servers. Hosts which may disconnect at any time, therefore a robust control protocol is needed to maintain connectivity among peers. This work presents a new peer-to-peer multicast protocol and analyzes the gains that video coding and prioritized packet scheduling at the application layer can bring to the overall streaming performance. A rate-distortion model which predicts end-to-end video quality in throughput limited environments is presented and used to determine the over-provisioning necessary to avoid self-inflicted congestion. The video stream transmitted by the source contains H.264 SP and SI frames, which are used to adaptively stop error propagation due to packet loss. Distortion-optimized retransmission requests are issued by receiving hosts to recover the most important missing packets while limiting the induced congestion. Experiments for several hundred hosts simulated in NS-2 illustrate the benefits of our system. We achieve typical end-to-end delays of 1 sec, and a stable video quality with less than 2.5% of frames lost to playout interruptions.

79 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023139
2022336
2021399
2020535
2019609
2018673