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Let the Crowd be Heard - A Crowdsourcing-based Study on Video Coding
Zach, Ondřej
In this paper, we present a crowdsourcing-based study on video codec comparison. We compared the perceived quality of sequences encoded using H.264 and H.265 algorithms. The main advantage of the study is, that the users could watch the videos in their natural environment using their own equipment. The results show, that H.265 may not bring a significantly better quality in SD scenarios, however, in other scenarios, the use of H.265 might be preferred.
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Cross-platform performance testing of open source PBX FreeSWITCH
Melichar, Ondřej ; Kováč, Dominik (referee) ; Šilhavý, Pavel (advisor)
This bachelor’s thesis deals with the open source private branch exchange FreeSWITCH. The thesis describes the process of installation and consecutive configuration of the telephone system on various distributions of platforms Windows and Linux. Emphasis is placed on comparison of the performance between these systems and also the quality of calls as well as transcoding functionality. Specifically, the performance of the telephone system is tested while using the SIP protocol. Thesis also contains an introduction into the subject and a brief description of the FreeSWITCH architecture and its functions and capabilities.
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Methods for measurement of data network performance and quality parameters
Sukup, Luboš ; Zeman, Václav (referee) ; Novotný, Vít (advisor)
Master thesis involves the development of quality measurement issues and performance parameters in data networks. It describes the main technologies as they affect the quality and performance parameters and the effect of these parameters for voice, video and data services. Next are listed some methods for measuring parameters of the data network.In the practical part is selected one method of measuring network parameters and properties of this method are demonstrated by illustrative examples.
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Impact of resolution change on subjective QoE measurement of streaming video
Nevřelová, Monika ; Pokorný, Jiří (referee) ; Kováč, Dominik (advisor)
This thesis deals with the process of development of web application for subjective evaluation of streaming video. The thesis describes the adaptive streaming technique, streaming services and both subjective and objective evaluation of streaming video. Methods for measuring of subjective evaluation (namely laboratory method and crowdsourcing method) are described in more detail. A special web-based tool for subjective evaluation of streaming video was created with use of HTML, PHP and MySQL languages. To simulate the network changes, such as changes of the bandwidths, there´re created scenarios where the player selects the quality of the streamed video. The process of collecting data via Laboratory method and Crowdsourcing method is described in the thesis. Collected data are then analyzed.
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Android application for measuring user satisfaction with mobile data service
Kunc, Jaroslav ; Povoda, Lukáš (referee) ; Červenák, Rastislav (advisor)
The bachelor thesis focuses on user satisfaction with mobile data services. The thesis in this context explains the terms of Quality of Service, Quality of Experience and Crowdsourcing. An another part of a thesis is focusing on describing the development of applications for the Android platform, including the distribution and application testing. In the practical part of thesis, the application for the Android platform is created and it is predicting the user satisfaction with mobile data services on the basis of an analytical model for calculating MOS (Mean Opinion Score).
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SDN Routing According to Transmitted Content
Gavryliuk, Olga ; Franková, Barbora (referee) ; Holkovič, Martin (advisor)
This works main point of focus is routing in software defined networks, which allow routing based on transfered packets. For accomplishing this task it was necessary to create a detection mechanism, that finds the connection within the OS which needs priority handling. New connections are sent via a routing aplication which is running on the SDN controller POX. The controller divides applications based on two criteria: The application requiring the largest bandwidth and the application requiring the fastest route. For this purpose four algorithms for routing data based on application preferences were designed and implemented. The applications were implemented in the Python language and they were tested in the simulation tool Mininet.
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Web application for subjective evaluation of streamed video
Lipa, Matúš ; Červenák, Rastislav (referee) ; Kováč, Dominik (advisor)
This work deals with creating web application for subjective evaluation of streamed video and parts which are necessary. Streaming techniques are described from simple classical technique to adaptive bitrate streaming techniques. This work focus on adaptive bitrate streaming technology using MPEG - DASH and editing video source with tool FFmpeg. With using JavaScript is create a player who´s able to simulate changes in the network as a change in available bandwidth. It´s possible to create scenarios under which the player selects the video playback quality. The player is placed into a complex tool for evaluation of quality of experience.
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New video coding algorithms
Zach, Ondřej ; Počta,, Peter (referee) ; Fliegel, Karel (referee) ; Slanina, Martin (advisor)
Předložená dizertační práce se zabývá moderními algoritmy pro kódovaní videosekvencí, zejména algoritmem High Efficiency Video Coding, a jeho použítím v prostředí online streamování. Vzhledem k tomu, že chování koncových diváků směřuje ke sledování video obsahu kdykoli a kdekoli, způsob, jakým je obsah doručen k divákovi, se stává stejně důležitým, jakým je samotné kódování. V této práci se zaměřujeme na užití HEVC ve službách založených na HTTP adaptivním streamování, zejména ve službách využívajích DASH. Dále se zabýváme dalšími aspekty, které mají vliv na kvalitu zážitku (Quality of Experience) tak, jak jej vnímá koncový uživatel. Takovými jsou na příklad přítomnost reklamy či další systémové parametry. Abychom mohli sbírat názory uživatelů, pro naše experimenty často používáme crowdsourcing. Z tohoto důvodu je část této práce věnována samotnému crowdsourcingu a tomu, jak jej lze využít pro hodnocení kvality videa.
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Impact of rebuffering events on subjective QoE measurement of streaming video
Hůrek, Marek ; Pokorný, Jiří (referee) ; Kováč, Dominik (advisor)
This bachelor thesis mainly deals with the creation of a web-tool for subjective evaluation of quality of video in initial and repeated video loading and buffering. The simulation of adaptive streaming, focused on buffering, is performed on the basis of scenarios created in the database that are randomly generated and implemented into the aforementioned web-tool. The theoretical part of this thesis is focused on the analyzation of different types of streaming, streaming services and QoE service (subjective and objective evaluation). Two basic methods for the subjective evaluation (laboratory method and crowdsourcing) are described in more detail. At the end there are analyzed data received from measurement. Results are put into graphs with a description of subjective evaluation MOS.
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