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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Atvirojo kodo vaizdo kodavimo H.264 realizacijų, aprašytų aparatūros aprašymo kalbomis, tyrimas / Research of open source H.264 video coding implementations described in hardware description languages

Kriščiūnas, Eugenijus 04 November 2013 (has links)
H.264/AVC yra pagrįstas tradicinėmis vaizdo kodavimo sąvokomis, bet palyginti su ankstesniais standartais, su svarbiais tam tikrais skirtumais.Reikšmingiausi skirtumai yra padidintas judėjimo apskaičiavimo pajėgumas, mažas bloko dydis su tikslia transformacija, adaptyvus blokų mažinimo filtras ir patobulinti entropijos kodavimo metodai. palygintų su MPEG-2. H.264/AVC pasiekia daugiau kaip 50 procentų, kodavimo prieaugį palyginus su MPEG-2 visuose PSNR situacijose. H.264/AVC standartas dirba žymiai geriau už visus ankstesnius standartus, dėl padidėjusio kodavimo lankstumo ir sudėtingumo. / Video coding is the entire process of compressing and decompressing of a digital video signal. Then the mainstream video compression tools developed in the past several years by both Video Coding Experts Group (VCEG) and Moving Picture Experts Group (MPEG) are briefly introduced. Since its invention from early 1990 modern digital video compression techniques have played an important role in the world of telecommunication and multimedia systems where bandwidth is still a valuable commodity. Evolution from the early MPEG-1/H.261 to the current H.264/AVC video codec gradually improves the coding efficiency at the cost of design complexity. Compared with its prior standards the H.264/AVC is able to achieve nearly doubled coding gain, while the encoder's and decoder's complexity increase 5 – 10 and 2 – 3 times respectively.
2

Hardware Implementation of a High Speed Deblocking Filter for the H.264 Video Codec

Dickey, Brian January 2012 (has links)
H.264/MPEG-4 part 10 or Advanced Video Coding (AVC) is a standard for video compression. MPEG-4 is currently one of the most widely used formats for recording, compression and distribution of high definition video. One feature of the AVC codec is the inclusion of an in-loop deblocking filter. The goal of the deblocking filter is to remove blocking artifacts that exist at macroblock boundaries. However, due to the complexity of the deblocking algorithm, the filter can easily account for one-third of the computational complexity of a decoder. In this thesis, a modification to the deblocking algorithm given in the AVC standard is presented. This modification allows the algorithm to finish the filtering of a macroblock to finish twenty clock cycles faster than previous single filter designs. This thesis also presents a hardware architecture of the H.264 deblocking filter to be used in the H.264 decoder. The developed architecture allows the filtering of videos streams using 4:2:2 chroma subsampling and 10-bit pixel precision in real-time. The filter was described in VHDL and synthesized for a Spartan-6 FPGA device. Timing analysis showed that is was capable of filtering a macroblock using 4:2:0 chroma subsampling in 124 clock cycles and 4:2:2 chroma subsampling streams in 162 clock cycles. The filter can also provide real-time deblocking of HDTV video (1920x1080) of up to 988 frames per second.
3

Hardware Implementation of a High Speed Deblocking Filter for the H.264 Video Codec

Dickey, Brian January 2012 (has links)
H.264/MPEG-4 part 10 or Advanced Video Coding (AVC) is a standard for video compression. MPEG-4 is currently one of the most widely used formats for recording, compression and distribution of high definition video. One feature of the AVC codec is the inclusion of an in-loop deblocking filter. The goal of the deblocking filter is to remove blocking artifacts that exist at macroblock boundaries. However, due to the complexity of the deblocking algorithm, the filter can easily account for one-third of the computational complexity of a decoder. In this thesis, a modification to the deblocking algorithm given in the AVC standard is presented. This modification allows the algorithm to finish the filtering of a macroblock to finish twenty clock cycles faster than previous single filter designs. This thesis also presents a hardware architecture of the H.264 deblocking filter to be used in the H.264 decoder. The developed architecture allows the filtering of videos streams using 4:2:2 chroma subsampling and 10-bit pixel precision in real-time. The filter was described in VHDL and synthesized for a Spartan-6 FPGA device. Timing analysis showed that is was capable of filtering a macroblock using 4:2:0 chroma subsampling in 124 clock cycles and 4:2:2 chroma subsampling streams in 162 clock cycles. The filter can also provide real-time deblocking of HDTV video (1920x1080) of up to 988 frames per second.
4

Optimisation conjointe source/canal d'une transmission vidéo H.264/AVC sur un lien sans fil

Bergeron, Cyril 24 January 2007 (has links) (PDF)
Dans le domaine des transmissions de données multimédia, de remarquables progrès ont été fait au cours des vingt dernières années permettant d'optimiser chaque module d'une chaîne de communication moderne. Mais en dépit de ces excellents résultats, une approche cloisonnée ou "séparée" a montré ses limites dans le cas des communications sans fil. Notre approche, qui suit celle du codage source/canal conjoint, a pour objectif de développer des stratégies où le codage de source et le codage canal sont déterminés conjointement tout en prenant en compte les paramètres du réseau et d'éventuelles contraintes utilisateurs. Cette approche offre la possibilité de faire converser le monde de l'application (codage source, chiffrement) et le monde des transmissions (codage canal) afin qu'ils optimisent conjointement l'usage du lien de communications sans fil de bout en bout. Trois axes de recherche sont traités dans ce mémoire de thèse qui permettent d'optimiser l'allocation des ressources de l'utilisateur et du réseau appliquée tout en assurant une compatibilité avec la norme de codage vidéo H.264. Tout d'abord, nous proposons d'utiliser la redondance résiduelle présente dans un flux binaire en sortie du codeur source afin d'améliorer les performances du décodage. Ensuite, nous introduisons une méthode proposant des propriétés de scalabilité temporelle compatible du standard H.264. Enfin, nous présentons une méthode d'optimisation conjointe de la répartition de débit entre le codeur de source et le codeur de canal au moyen d'un contrôleur applicatif estimant la distorsion globale introduite par ces différents codeurs grâce au calcul de la sensibilité des flux binaires considérés.
5

在WiMAX下以跨層設計改進自動重送要求以提升MPEG-4影像串流品質 / Adapt ARQ to Improve MPEG-4 Video Streaming Based on MAC-centric Cross Layer Design in WiMAX

盛鵬宇, Sheng, Peng Yu Unknown Date (has links)
網路使用率逐漸普及、傳輸技術的進步以及通訊網路蓬勃發展,提供人們許多生活上的便利,無線網路已經成為現代通訊市場上的新寵兒。其中,IEEE於1999年開始制定與修正WiMAX,此協定在無線網路的應用視為解決”最後一哩”接取問題的利器。然而,無線網路仍舊會遇到傳送訊號耗弱、通訊死角或是氣候干擾等種種原因造成傳輸失敗的問題。 MPEG-4編碼上,考慮影音封包具有不同重要性的意義,針對影音封包需制定不同的重傳機制,本研究先行改善WiMAX中ARQ(Auto Repeat Request)的流程,再利用跨層設計使得MAC層可以辨識影音封包資訊,確保GOP-tree中之"骨幹"節點穩定的抵達率,再利用Lagrange’s Method of Multiplier方法,針對GOP-tree中非骨幹部分提出合適的trade-off客製化。最後本研究藉由網路模擬器NS-2(Network Simulater ver. 2)與myEvalvid-NT的實驗架構,做不同效能的評比,並以PSNR值評估所提出之方法的有效性。 / The growing of network popularity, progressing of trasmission technology and development of communication network have facilitated our daily life these years. Wireless network has become a new favor at modern communication market. Among of them, IEEE has started to design and modify specification of WiMAX since 1999, which has been thought to be the solution toward “last mile”. But, there still exist problems such as Doppler effect, blind corner of communication and obstruction of weather condition, which cause the failure of communication. MPEG-4 coding would concern the different significances of distinct types of packets, we should define retransmission strategies for different multimedia packets, respectively. Firstly, we improve the process of ARQ(Auto Repeat reQuest). Secondly, we use MAC-centric design to distinguish multimedia packets and guarantee the arrival rate of packets in the “backbone nodes” of a group of pictures tree. Thirdly, Lagrange’s Method of Multiplier is used to customize the trade-off of “non-backbone node”. In the end, we have performance evaluations by NS-2(Network Simulator ver. 2) and myEvalvid-NT, to verify the efficiency of the proposed method using Peak Signal to Noise Ratio.
6

Přenos a zobrazení videa v prohlížeči pro záznam pracovní plochy / Processing and Streaming Video in Browser for Screen Recording

Svačina, Lukáš January 2016 (has links)
Aim of the thesis is to design and implement unique service based on the newest technologies in web apps fi eld which allows screen recording followed by P2P distribution between participating users using web browser only. Thesis deals with the analysis of modern and coming technologies which allow practical implementation of such a service. It involves obtaining access to the screen source data, its recording, transforming and transmission over the network followed by playing on the other side. Recorded videos are adapted for part by part use in a player with seeking capability. Distributed architecture for data exchange between peers using peer-to-peer connection based on hybrid P2P VoD network provides scalability of the solution. The player allows obtaining the necessary parts of the videos from the current watchers with smooth video playback experience during ongoing transmissions whilst allowing arbitrary video shifting. In consideration of early stages of development or experimental support for some of the APIs needed for this work, research into browsers' support with discussion on realistic applicability nowadays is always performed.
7

Untersuchen von internetbasierten Videostreamingverfahren und -techniken auf Verwendbarkeit für regionale Fernsehsender

Meixner, Christian 21 August 2007 (has links) (PDF)
Im Rahmen der vorliegenden Diplomarbeit werden browserbasierte Videoüber-tragungslösungen bezüglich ihrer Verwendbarkeit zur Übertragung des Fernsehprogramms regionaler Fernsehsender auf das Medium Internet untersucht, mit dem Ziel eine Prototypanwendung auf Basis der gemäß den Anforderungen der Regionalsender am besten geeigneten Technik zu implementieren. Grundlage der Untersuchung bildet eine Gegenüberstellung der am Markt be-findlichen Videosysteme mit Webbrowserunterstützung QuickTime, RealVideo, Windows Media, Adobe Flash und Java. Die Systeme werden bezüglich ihres Leistungsumfangs, der Flexibilität ihrer Einsatzmöglichkeiten, der Qualität der zugrundeliegenden Videocodecs und ihrer Verbreitung im Internet verglichen. Anhand der gemeinsam mit den Regionalsendern KabelJournal und Sachsenfernsehen ermittelten Anforderungen an ein Videosystem zur Übertragung ihres Programms im Internet, erweist sich Adobe Flash Video durch seine hohe Verbreitung, seine flexiblen Einsatzmöglichkeiten und seiner Unterstützung von Bewegtbild-, Standbild- und interaktiven Animationsmedien als am besten geeignet. Die im Rahmen dieser Arbeit erstellte Implementierung einer Web-TV Anwen-dung auf Basis von Adobe Flash zeigt bei der Ermittlung von konkreten Einsatzszenarien bei den Sendern KabelJournal und Sachsenfernsehen, dass durch die multimediale Auslegung, die flexiblen Medienkombinationsmöglichkeiten und die offene XML-Schnittstelle mehr als eine bloße Portierung des TV-Programms ins Internet mit gleichzeitig geringem Aufwand möglich ist. Die Web-TV Anwendung ist eine einfach einsetzbare aber höchst vielseitige Möglichkeit für Regionalsender neue Märkte zu erschließen. / Within the present diploma thesis, established web browser based video solu-tions are examined for their use as internet broadcasting system for local TV stations, with the intention of implementing a broadcasting solution based on the technique matching the requirements of local TV stations best. Basis of this examination is the comparison of the web video solutions Quick-Time, RealVideo, Windows Media, Adobe Flash and Java. These systems are compared by their multimedia support, flexibility of use, quality of the video co-decs they use and their market penetration. On the basis of the requirements of local TV stations, determined together with KabelJournal and Sachsenfernsehen, adobe flash is the most satisfying solution to build a Web TV application upon. Its market penetration, flexibility of use and its support for still images, videos and interactive animations match those requirements best. The implementation of the Web TV application based on adobe flash proofs its great flexibility, ease of use and its diverse variations in combining different me-dia, at the determination of concrete use cases together with KabelJournal and Sachsenfernsehen. It shows that this is an easy but high potential way to enter new markets for local TV stations.
8

Untersuchen von internetbasierten Videostreamingverfahren und -techniken auf Verwendbarkeit für regionale Fernsehsender

Meixner, Christian 02 July 2007 (has links)
Im Rahmen der vorliegenden Diplomarbeit werden browserbasierte Videoüber-tragungslösungen bezüglich ihrer Verwendbarkeit zur Übertragung des Fernsehprogramms regionaler Fernsehsender auf das Medium Internet untersucht, mit dem Ziel eine Prototypanwendung auf Basis der gemäß den Anforderungen der Regionalsender am besten geeigneten Technik zu implementieren. Grundlage der Untersuchung bildet eine Gegenüberstellung der am Markt be-findlichen Videosysteme mit Webbrowserunterstützung QuickTime, RealVideo, Windows Media, Adobe Flash und Java. Die Systeme werden bezüglich ihres Leistungsumfangs, der Flexibilität ihrer Einsatzmöglichkeiten, der Qualität der zugrundeliegenden Videocodecs und ihrer Verbreitung im Internet verglichen. Anhand der gemeinsam mit den Regionalsendern KabelJournal und Sachsenfernsehen ermittelten Anforderungen an ein Videosystem zur Übertragung ihres Programms im Internet, erweist sich Adobe Flash Video durch seine hohe Verbreitung, seine flexiblen Einsatzmöglichkeiten und seiner Unterstützung von Bewegtbild-, Standbild- und interaktiven Animationsmedien als am besten geeignet. Die im Rahmen dieser Arbeit erstellte Implementierung einer Web-TV Anwen-dung auf Basis von Adobe Flash zeigt bei der Ermittlung von konkreten Einsatzszenarien bei den Sendern KabelJournal und Sachsenfernsehen, dass durch die multimediale Auslegung, die flexiblen Medienkombinationsmöglichkeiten und die offene XML-Schnittstelle mehr als eine bloße Portierung des TV-Programms ins Internet mit gleichzeitig geringem Aufwand möglich ist. Die Web-TV Anwendung ist eine einfach einsetzbare aber höchst vielseitige Möglichkeit für Regionalsender neue Märkte zu erschließen. / Within the present diploma thesis, established web browser based video solu-tions are examined for their use as internet broadcasting system for local TV stations, with the intention of implementing a broadcasting solution based on the technique matching the requirements of local TV stations best. Basis of this examination is the comparison of the web video solutions Quick-Time, RealVideo, Windows Media, Adobe Flash and Java. These systems are compared by their multimedia support, flexibility of use, quality of the video co-decs they use and their market penetration. On the basis of the requirements of local TV stations, determined together with KabelJournal and Sachsenfernsehen, adobe flash is the most satisfying solution to build a Web TV application upon. Its market penetration, flexibility of use and its support for still images, videos and interactive animations match those requirements best. The implementation of the Web TV application based on adobe flash proofs its great flexibility, ease of use and its diverse variations in combining different me-dia, at the determination of concrete use cases together with KabelJournal and Sachsenfernsehen. It shows that this is an easy but high potential way to enter new markets for local TV stations.
9

無線多媒體傳輸技術發展對無線影音產業價值鏈的影響以歐特斯科技公司為例

葛葆華, Edward Ko Unknown Date (has links)
無線寬頻網路(Mobile Internet Broadband Network)的出現對於無線通訊產業、傳播媒體產業與影音內容產業產生了相當程度的影響,而數位化的科技發展更帶來通訊、傳播及平面媒體產業融合的可能性,無線寬頻影音串流(Mobile Internet Video Streaming)是一架構在此無線通訊媒體匯流後的新產物,透過觀察和分析它的演進發展,可以說明和解釋網路新媒體匯流造成傳統影音產業價值鏈的改變。 吾人將以無線通訊之影音播放技術之演進與發展,以及相對最先發生變化之影音產業經營環境,產生之影響,做產業價值鏈分析研究,進而了解產業經營環境之改變,新的價值創造流程及技術平台的關聯性。並藉由日本NTT DOCOMO之經驗,及對其供應商之觀察,了解台灣產業發展之可能趨勢,及策略建議藍圖。 本研究採P.W. Bane、S.P. Bradley & D.J. Collis (1998)三人提出之寬頻產業五層模式作為分析工具。五層模式分為內容(content)、包裝(package)、傳輸網路(transmission)、操作(manipulation) 及終端設備(terminal)五層架構。主要目的為以整體網路頻寬及技術演進的觀點進行分析五層間價值消長之關係,及整體網路之價值之改變。 我們發現在新的技術導入既有影音市場,由於網路之雙向特性,會產生網路效應及網路外部性,這些地方將產生新的價值所在,而擁有網路外部性的影音操作平台可獲得較高的價值。完整而消費者導向的影音操作平台,將首先累積產業之價值所在,影音操作平台的擁有者將成為產業的領導者,最終將成為標準的制定者。 影音內容的價值獲得來自網路外部性是經由更多人與內容來源(內容提供者)互動,造成下一次消費或其他使用者的外部性以及生產外部性,這樣的外部性是由虛擬連結產生.價值聚集於內容包裝層。 無線寬頻影音操作平台是服務成功的關鍵,有效的整合價值鏈及應用是必須在產業發展前完成,而完整的影音操作平台包含:內容製作壓縮平台、串流平台、訊息平台、及手機之用戶播放平台。 我們發現,新的技術導入市場,需要事先將價值鏈重新定義,整合出可行之新的商業模式,再依據新的價值鏈,新的服務流程去整合新的操作平台,投入服務後,由於是消費者導向的服務設計,可以降低消費者對新科技及新服務的學習門檻及進入障礙,而獲得市場認同。 / “Unlimited boundary & Ubiquitous content” Because of the improving the bandwidth & compression technology of mobile Internet, there are a very extremely industrial convergency in communication, broadcasting, & video audio content industry. There are several new technology including streaming, MPEG, multi media message, 3G which push the whole world going to a new Ubiquitous environment & totally change the old value chain of video audio industry, but we still have no ideal where it should go & what will happen next. We will try to research the technical evolution of video broadcasting which really influence our movie, TV industry. It will change the customer behavior of watching TV, or going to the movie. We especially want to find out where is the new value in the mobile Internet multi media industry. We will use the 5 liars analysis model of broadband industry (P.W. Bane、S.P. Bradley & D.J. Collis (1998))as our basic methodology to find out how the three vertical industries became a new 5 horizontal industries, which are content, package, transmission, manipulation, & terminal. We also want to know how they work internally & externally. We find that the video audio manipulation platform will become the key solution for this value chain, because of its network externality & network effect. The content providers also very important to provide the quality of contents to service the end customers. How to consolidate a new valuable services process & user friendly interface is the big issue here for whom will invest a large of money to creat the new mobile internet portal & new audio vedio manipulation platform. They must think not only the user interface of handset, but also the mechanism of profit sharing between these different providers who never work together in the history.

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