78 research outputs found
Robust P2P Live Streaming
Projecte fet en col.laboració amb la Fundació i2CATThe provisioning of robust real-time communication services (voice, video, etc.) or media contents through the Internet in a distributed manner is an important challenge,
which will strongly influence in current and future Internet evolution. Aware of this, we
are developing a project named Trilogy leaded by the i2CAT Foundation, which has as
main pillar the study, development and evaluation of Peer-to-Peer (P2P) Live
streaming architectures for the distribution of high-quality media contents. In this
context, this work concretely covers media coding aspects and proposes the use of
Multiple Description Coding (MDC) as a flexible solution for providing robust and
scalable live streaming over P2P networks. This work describes current state of the art
in media coding techniques and P2P streaming architectures, presents the
implemented prototype as well as its simulation and validation results
Robust P2P Live Streaming
Projecte fet en col.laboració amb la Fundació i2CATThe provisioning of robust real-time communication services (voice, video, etc.) or media contents through the Internet in a distributed manner is an important challenge,
which will strongly influence in current and future Internet evolution. Aware of this, we
are developing a project named Trilogy leaded by the i2CAT Foundation, which has as
main pillar the study, development and evaluation of Peer-to-Peer (P2P) Live
streaming architectures for the distribution of high-quality media contents. In this
context, this work concretely covers media coding aspects and proposes the use of
Multiple Description Coding (MDC) as a flexible solution for providing robust and
scalable live streaming over P2P networks. This work describes current state of the art
in media coding techniques and P2P streaming architectures, presents the
implemented prototype as well as its simulation and validation results
Platforms for handling and development of audiovisual data
Estágio realizado na MOG Solutions e orientado por Vítor TeixeiraTese de mestrado integrado. Engenharia Informátca e Computação. Faculdade de Engenharia. Universidade do Porto. 200
MediaSync: Handbook on Multimedia Synchronization
This book provides an approachable overview of the most recent advances in the fascinating field of media synchronization (mediasync), gathering contributions from the most representative and influential experts. Understanding the challenges of this field in the current multi-sensory, multi-device, and multi-protocol world is not an easy task. The book revisits the foundations of mediasync, including theoretical frameworks and models, highlights ongoing research efforts, like hybrid broadband broadcast (HBB) delivery and users' perception modeling (i.e., Quality of Experience or QoE), and paves the way for the future (e.g., towards the deployment of multi-sensory and ultra-realistic experiences). Although many advances around mediasync have been devised and deployed, this area of research is getting renewed attention to overcome remaining challenges in the next-generation (heterogeneous and ubiquitous) media ecosystem. Given the significant advances in this research area, its current relevance and the multiple disciplines it involves, the availability of a reference book on mediasync becomes necessary. This book fills the gap in this context. In particular, it addresses key aspects and reviews the most relevant contributions within the mediasync research space, from different perspectives. Mediasync: Handbook on Multimedia Synchronization is the perfect companion for scholars and practitioners that want to acquire strong knowledge about this research area, and also approach the challenges behind ensuring the best mediated experiences, by providing the adequate synchronization between the media elements that constitute these experiences
Data Processing and Fusion For Multi-Source Wireless Systems
The constant evolution of the telecommunication technologies is one fundamental aspect that characterizes the modern era. In the context of healthcare and security, different scenarios are characterized by the presence of multiple sources of information that can support a large number of innovative services. For example, in emergency scenarios, reliable transmission of heterogeneous information (health conditions, ambient and diagnostic videos) can be a valid support for managing the first-aid operations. The presence of multiple sources of information requires a careful communication management, especially in case of limited transmission resource availability. The objective of my Ph.D. activity is to develop new optimization techniques for multimedia communications, considering emergency scenarios characterized by wireless connectivity. Different criteria are defined in order to prioritize the available heterogeneous information before transmission. The proposed solutions are based on the modern concept of content/context awareness: the transmission parameters are optimized taking into account the informative content of the data and the general context in which the information sources are located. To this purpose, novel cross-layer adaptation strategies are proposed for multiple SVC videos delivered over wireless channel. The objective is to optimize the resource allocation dynamically adjusting the overall transmitted throughput to meet the actual available bandwidth. After introducing a realistic camera network, some numerical results obtained with the proposed techniques are showed. In addition, through numerical simulations the benefits are showed, in terms of QoE, introduced by the proposed adaptive aggregation and transmission strategies applied in the context of emergency scenarios. The proposed solution is fully integrated in European research activities, including the FP7 ICT project CONCERTO. To implement, validate and demonstrate the functionalities of the proposed solutions, extensive transmission simulation campaigns are performed. Hence, the presented solutions are integrated on a common system simulator which is been developed within the CONCERTO project
Understanding the performance of Internet video over residential networks
Video streaming applications are now commonplace among home Internet users, who typically access the Internet using DSL or Cable technologies.
However, the effect of these technologies on video performance, in terms of degradations in video quality, is not well understood.
To enable continued deployment of applications with improved quality of experience for home users, it is essential to understand the nature of network impairments and develop means to overcome them.
In this dissertation, I demonstrate the type of network conditions experienced by Internet video traffic, by presenting a new dataset of the packet level performance of real-time streaming to residential Internet users.
Then, I use these packet level traces to evaluate the performance of commonly used models for packet loss simulation, and finding the models to be insufficient, present a new type of model that more accurately captures the loss behaviour.
Finally, to demonstrate how a better understanding of the network can improve video quality in a real application scenario, I evaluate the performance of forward error correction schemes for Internet video using the measurements.
I show that performance can be poor, devise a new metric to predict performance of error recovery from the characteristics of the input, and validate that the new packet loss model allows more realistic simulations.
For the effective deployment of Internet video systems to users of residential access networks, a firm understanding of these networks is required.
This dissertation provides insights into the packet level characteristics that can be expected from such networks, and techniques to realistically simulate their behaviour, promoting development of future video applications
Real-time video streaming using peer-to-peer for video distribution
The growth of the Internet has led to research and development of several new and useful applications including video streaming. Commercial experiments are underway to determine the feasibility of multimedia broadcasting using packet based data networks alongside traditional over-the-air broadcasting. Broadcasting companies are offering low cost or free versions of video content online to both guage and at the same time generate popularity. In addition to television broadcasting, video streaming is used in a number of application areas including video conferencing, telecommuting and long distance education. Large scale video streaming has not become as widespread or widely deployed as could be expected. The reason for this is the high bandwidth requirement (and thus high cost) associated with video data. Provision of a constant stream of video data on a medium to large scale typically consumes a significant amount of bandwidth. An effect of this is that encoding bit rates are lowered and consequently video quality is degraded resulting in even slower uptake rates for video streaming services. The aim of this dissertation is to investigate peer-to-peer streaming as a potential solution to this bandwidth problem. The proposed peer-to-peer based solution relies on end user co-operation for video data distribution. This approach is highly effective in reducing the outgoing bandwidth requirement for the video streaming server. End users redistribute received video chunks amongst their respective peers and in so doing increase the potential capacity of the entire network for supporting more clients. A secondary effect of such a system is that encoding capabilities (including higher encoding bit rates or encoding of additional sub-channels) can be enhanced. Peer-to-peer distribution enables any regular user to stream video to large streaming networks with many viewers. This research includes a detailed overview of the fields of video streaming and peer-to-peer networking. Techniques for optimal video preparation and data distribution were investigated. A variety of academic and commercial peer-to-peer based multimedia broadcasting systems were analysed as a means to further define and place the proposed implementation in context with respect to other peercasting implementations. A proof-of-concept of the proposed implementation was developed, mathematically analyzed and simulated in a typical deployment scenario. Analysis was carried out to predict simulation performance and as a form of design evaluation and verification. The analysis highlighted some critical areas which resulted in adaptations to the initial design as well as conditions under which performance can be guaranteed. A simulation of the proof-of-concept system was used to determine the extent of bandwidth savings for the video server. The aim of the simulations was to show that it is possible to encode and deliver video data in real time over a peer-to-peer network. The proposed system achieved expectations and showed significant bandwidth savings for a sustantially large video streaming audience. The implementation was able to encode video in real time and continually stream video packets on time to connected peers while continually supporting network growth by connecting additional peers (or stream viewers). The system performed well and showed good performance under typical real world restrictions on available bandwith capacity.Dissertation (MEng)--University of Pretoria, 2009.Electrical, Electronic and Computer Engineeringunrestricte
Eine Netzwerkarchitektur zum Einsatz des Material Exchange Formats für Live-Produktionen im professionellen Fernsehstudio
Der Bereich der Liveproduktion im Fernsehstudio ist geprägt von hohen
Anforderungen an Qualität, Zeitverhalten und Zuverlässigkeit bei der
Erstellung von Audio- und Videomaterial zur Distribution über
Broadcastkanäle. In der Vergangenheit konnten diese Anforderungen nur mit
spezieller und damit kostenintensiver Gerätetechnik bewältigt werden. Mit
der Entwicklung auf dem Elektroniksektor ist heute einerseits eine Vielzahl
von zusätzlichen Distributionswegen mit Inhalten zu versorgen. Andererseits
stehen leistungsfähige Geräte auf Basis von Standard-IT-Technologien zur
Verfügung, die senderseitig zur Produktion von Material eingesetzt werden
können und zusätzlich Datenverarbeitung leisten, welche Produktionsabläufe
effizienter gestaltet.Die vorliegende Dissertation beschäftigt sich vor
diesem Hintergrund mit der Anwendung von Standard-IT-Technologien im
echtzeitkritischen Bereich der Fernsehstudioproduktion. Dabei besteht
insbesondere das Ziel der Integration von Metadatenverarbeitung. Die Arbeit
kombiniert dazu Standard-IT-Technologien und ergänzt diese um Konzepte, die
die besonderen Anforderungen einer Liveproduktion im
Fernsehproduktionsstudio berücksichtigen. Im Rahmen dieser Arbeit wird eine
Übertragungstechnologie zum Datenaustausch im Studio aus
Standardkomponenten modelliert. Parameter zur Bewertung der
Netzwerkleistung und Strategien zur Ressourcenteilung werden diskutiert. Im
weiteren Verlauf der Arbeit werden Prozessoren zur Verarbeitung von
Essenzdaten verglichen und über die PC-Plattform in eine universelle
Einheit zur Datenverarbeitung integriert. Die Analyse von Komponenten und
Abläufen führt zu einer feingranularen Latenzbetrachtung, die eine
Grundlage für Optimierungsstrategien mit dem Ziel einer latenzarmen
Implementierung darstellt. Das Ziel der Metadatenintegration wird mit dem
Einbinden des Material Exchange Formats erreicht, das die synchronisierte
Übertragung von Essenz- und Metadaten erlaubt. Die Arbeit identifiziert
weiterhin Anwendungsszenarien, in denen Metadaten auch in
echtzeitkritischen Live-Produktionen genutzt werden können. Eine
prototypische Implementierung bildet abschließend die Grundlage zur
Verifikation getroffener Aussagen
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