3,996 research outputs found
Scalable Video Streaming over the Internet
The objectives of this thesis are to investigate the challenges on video streaming, to explore and compare different video streaming mechanisms, and to develop video streaming algorithms that maximize visual quality. To achieve these objectives, we first investigate scalable video multicasting schemes by comparing layered video multicasting with replicated stream video multicasting. Even though it has been generally accepted that layered video multicasting is superior to replicated stream multicasting, this assumption is not based on a systematic and quantitative comparison. We argue that there are indeed scenarios where replicated stream multicasting is the preferred approach.
We also consider the problem of providing perceptually good quality of layered VBR video. This problem is challenging, because the dynamic behavior of the Internet's available bandwidth makes it difficult to provide good quality. Also a video encoded to provide a consistent quality exhibits significant data rate variability. We are, therefore, faced with the problem of accommodating the mismatch between the available bandwidth variability and the data rate variability of the encoded video. We propose an optimal quality adaptation algorithm that minimizes quality variation while at the same time increasing the utilization of the available bandwidth.
Finally, we investigate the transmission control protocol (TCP) for a transport layer protocol in streaming packetized media data. Our approach is to model a video streaming system and derive relationships under which the system employing the TCP protocol achieves desired performance. Both simulation results and the Internet experimental results validate this model and demonstrate the buffering delay requirements achieve desired video quality with high accuracy. Based on the relationships, we also develop realtime estimation algorithms of playout buffer requirements.Ph.D.Committee Chair: Mostafa H. Ammar; Committee Co-Chair: Yucel Altunbasak; Committee Member: Chuanyi Ji; Committee Member: George Riley; Committee Member: Henry Owen; Committee Member: Jack Brassi
Video streaming with quality adaption using collaborative active grid networks
Due to the services and demands of the end
users, Distributed Computing (Grid Technology,
Web Services, and Peer-to-Peer) has been
developedrapidJy in thelastyears. Theconvergence
of these architectures has been possible using
mechanisms such as Collaborative work and
Resources Sharing. Grid computing is a platform to
enable flexible, secure, controlled, scalable,
ubiquitous and heterogeneous services. On the
other hand, Video Streaming applications demand
a greater deployment over connected Internet users.
The present work uses the Acti ve Grid technology
as a fundamental platform to give a solution of
multimediacontentrecovery. This solution takes
into account the following key concepts:
collaborative work, multi-source recovery and
adapti ve quality. A new archi tecture is designed to
deliver video content over a Grid Network. The
acti ve and passi ve roles of the nodes are important
to guarantee a high quality and efficiency for the
video streaming system. The acti ve sender nodes
are the content suppliers, while the passive sender
nodes wiU perform the backup functions, based on
global resource control policies. The aim of the
backup node is minirnize the time to restore the
systemin caseoffailures. In this way, all participant
peers work in a collaborati ve manner following a
mul ti -source recovery scheme.
Furthermore, Video La yered Encoding is used
to manage the video data in a high scalable way,
di viding the video in multiple layers. This video
codification scheme enables thequality adaptation
according to the availability of system resources. In
addition, a buffer by sender peer and by layer is
needed for an effecti ve control ofthe video retrieve.
The QoS will fit considering the state of each buffer
and the measurement tools provide by the Acti ve
Grid on the network nodes. Ke ywords: Peer -to-Peer Grid Architecture,
Services for Active Grids, Streaming Media,
Layered Coding, Quality Adaptation, CoUaborative
Work.Peer Reviewe
Objective assessment of region of interest-aware adaptive multimedia streaming quality
Adaptive multimedia streaming relies on controlled
adjustment of content bitrate and consequent video quality variation in order to meet the bandwidth constraints of the communication
link used for content delivery to the end-user. The values of the easy to measure network-related Quality of Service metrics have no direct relationship with the way moving images are
perceived by the human viewer. Consequently variations in the video stream bitrate are not clearly linked to similar variation in the user perceived quality. This is especially true if some human visual system-based adaptation techniques are employed. As research has shown, there are certain image regions in each frame of a video sequence on which the users are more interested than in the others. This paper presents the Region of Interest-based Adaptive Scheme (ROIAS) which adjusts differently the regions within each frame of the streamed multimedia content based on the user interest in them. ROIAS is presented and discussed in terms of the adjustment algorithms employed and their impact on the human perceived video quality. Comparisons with existing approaches, including a constant quality adaptation scheme across the whole frame area, are performed employing two objective metrics which estimate user perceived video quality
Random Linear Network Coding for 5G Mobile Video Delivery
An exponential increase in mobile video delivery will continue with the
demand for higher resolution, multi-view and large-scale multicast video
services. Novel fifth generation (5G) 3GPP New Radio (NR) standard will bring a
number of new opportunities for optimizing video delivery across both 5G core
and radio access networks. One of the promising approaches for video quality
adaptation, throughput enhancement and erasure protection is the use of
packet-level random linear network coding (RLNC). In this review paper, we
discuss the integration of RLNC into the 5G NR standard, building upon the
ideas and opportunities identified in 4G LTE. We explicitly identify and
discuss in detail novel 5G NR features that provide support for RLNC-based
video delivery in 5G, thus pointing out to the promising avenues for future
research.Comment: Invited paper for Special Issue "Network and Rateless Coding for
Video Streaming" - MDPI Informatio
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