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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.
11

Vaizdo duomenų srauto apsaugos metodas, pagrįstas MPEG-2 transporto srauto daliniu šifravimu / Video stream protection method, based on MPEG-2 transport stream partial encryption

Simanaitis, Vytautas 04 November 2013 (has links)
Video srauto šifravimas yra pagrindinis intelektinės nuosavybės užtikrinimo metodas šiuolaikinėse skaitmeninių teisių valdymo sistemose (DRM). Egzistuojantys šifravimo metodai užtikrina labai aukštą apsaugos lygį, bet tuo pat metu reikalauja labai didelių skaičiavimo resursų ir yra sunkiai pritaikomi ribotų skaičiavimo resursų mobiliems vartotojų įrenginiams. Šiame straipsnyje pristatomas dalinis MPEG-2 transporto srauto šifravimo metodas, kuris yra tinkamas tokiems ribotų resursų terminaliniams vartotojų įrenginiams. Siūlomo metodo eksperimentinio įvertinimo rezultatai rodo, kad šifravimo ir dešifravimo laikai, lyginant su standartiniu pilnu šifravimu, yra sumažinami apie 7 kartus, todėl šis metodas yra tinkamas ribotų skaičiavimo resursų dešifravimo įrenginiams. / Video stream encryption is the main method for the protection of intellectual property in modern digital rights management systems (DRM). Existing encryption methods ensure very high protection level of encrypted content, but at the same time are very resources demanding, making them hardly suitable for low processing power mobile end-user devices. This paper presents partial MPEG-2 transport stream encryption method, which is suitable for such low power user terminals. The experimental evaluation of proposed method show that encryption and decryption times, comparing with standard full encryption, are reduced about 7 times, making proposed method a good choice for low processing power decryption devices.
12

[en] FOUNTAIN CODES AND OTHER CHANNEL CODING SCHEMES FOR PROTECTION OF TRANSPORT STREAMS OVER IP NETWORKS WITH PACKET ERASURE / [pt] CÓDIGOS FONTANAIS E OUTROS ESQUEMAS DE CODIFICAÇÃO DE CANAL PARA PROTEÇÃO DE TRANSPORT STREAMS EM REDES IP COM APAGAMENTO DE PACOTES

CLAUDIO ALEJANDRO SZABAS 06 July 2011 (has links)
[pt] Há, nos dias atuais, uma crescente demanda pelo transporte de video sobre IP, i.e., para distribuição de conteúdo pela Internet, por serviços de IPTV em definição padrão e em alta definição e, mesmo para uso interno nas redes de emissoras tradicionais de televisão, que transportam contribuições de elevada qualidade para seus programas. Em tais aplicações, o conteúdo dos programas é transportado usando MPEG-2 ou MPEG-4, sob a forma de MPEG-2 Transport Streams, encapsulados com protocolos tais como RTP, UDP e IP. As redes IP, que são modelizadas como Redes com Apagamento de Pacotes (PEC) não foram, no entanto, concebidas para o transporte de mídias em tempo real, esbarra portanto em problemas comuns como perdas de pacotes e jitter, gerando perturbações que se refletem na recepção do conteúdo. Os métodos tradicionais para superar estas dificuldades, como por exemplo, os que se baseiam em retransmissões usando protocolos ARQ (Automatic Repeat on Request), não são uma solução eficiente para proteger a transmissão de multimídia em tempo real. A proteção de multimídia transmitida em tempo real via IP recorre, neste caso, aos códigos para canal. Há códigos para canal recomendados em RFC s e Padrões, usados amplamente pelos fabricantes de equipamento. Os modernos Códigos Fontanais, possuem características atraentes para o transporte de conteúdos multimídia em tempo real. Neste trabalho, simulações são realizadas, onde o conteúdo encapsulado em Transport Stream, é protegido com Códigos Fontanais antes do encapsulamento para o envio através da rede. A título de comparação, o experimento é realizado também usando outros códigos para canal recomendados. Para realizar a comparação são usadas medições padronizadas do Transport Stream, medições objetivas como artefatos de blocagem e finalmente uma análise subjetiva do conteúdo recebido é usada. O trabalho conclui com a proposta de um Codificador de canal adaptável para Transport Stream. / [en] There is a growing demand for the transport of video over IP today, i.e., for content distribution over the Internet, IPTV services in Standard and High Definition, or even inside traditional broadcasters networks, transporting broadcast quality contributions to the main program. In such applications, the source encoded MPEG-2 or -4 content is transported in the form of MPEG-2 Transport Streams, encapsulated over network protocols. However, IP networks, which can be modeled as Packet Erasure Networks (PEC), were not originally designed for the transport of real time media. There are problems, such as packet drops and jitter, which generate severe impairments in the content that is decoded at the reception. Traditional methods for overcoming these problems, as for example retransmissions performed by Automatic Repeat Request (ARQ) protocols, are not suitable for real-time multimedia protection. Channel coding is the solution of choice for protecting real-time multimedia over IP. There are channel coding schemes specified in open recommendations and Standards, widely adopted by equipment vendors today. Fountain Codes present very attractive characteristics for the transport of real-time multimedia. In the present work, simulations with a Fountain code, protecting Transport Stream contents prior to network encapsulation, are presented. The experiment if repeated with other channel coding techniques commonly employed today. In order to analyze the decoded contents and obtain comparative results, standardized Transport Stream measurements, objective Blocking Artifacts measurements and subjective analysis of the decoded samples are employed. This work is concluded with the proposal of a Transport Stream Adaptive channel encoder, that is explained in Appendix-B.
13

Módulo IP de um Demultiplexador para o Subsistema Fluxo de Transporte- MPEG-2-Aderente ao Sistema Brasileiro de TV Digital

Medeiros, Leonardo 04 March 2010 (has links)
Made available in DSpace on 2015-05-14T12:36:55Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2141642 bytes, checksum: c8c8d7a9c0ea40b4a1ad5f10de888b74 (MD5) Previous issue date: 2010-03-04 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In the Brazilian scenario, the development of hardware components through computational methodologies and tools, available at affordable costs to education and research centers have make it feasible to design blocks and integrated circuit modules up to intellectual property IP level, focusing strategic areas of industry, specially those dedicated to the components for the Brazilian Digital Television System (SBTVD). This work deals with the architectural proposal development and validation for the Transport Stream MPEG-2 TS Subsystem of SBTVD transport stream demultiplexer from its specification and high-level modeling to its technology mapping implementation. As specific results, the structural and functional requirements of Transport Stream Subsystem MPEG-2 TS are detailed, the development of a software model for the demultiplexer and of an environment containing MPEG-2 TS flows that can validate the compliance with the SBTVD specification of models, an RTL-level MPEG-2 TS demultiplexer IP conceptual proof implementation and validation and its prototyping with technology mapping for FPGA and an ASIC design kit , are also presented. / No cenário brasileiro, o desenvolvimento de componentes de hardware através de metodologias e ferramentas computacionais, disponibilizados a custos acessíveis a centros de ensino e pesquisa tornou factível a possibilidade de se projetar até o nível de propriedade intelectual IP, blocos e módulos de circuitos integrados para atender áreas estratégicas da indústria, em especial aquelas voltadas aos componentes de produtos aderentes ao Sistema Brasileiro de Televisão Digital (SBTVD). Este trabalho trata o desenvolvimento e validação de uma proposta arquitetural para o Subsistema de Fluxo de Transporte MPEG-2 TS demultiplexador de fluxo de transporte do SBTVD, desde sua especificação e modelagem em alto-nível, até sua implementação no nível de mapeamento tecnológico. Também estão apresentados resultados específicos como o detalhamento dos requisitos estruturais e funcionais do Subsistema de Fluxo de Transporte MPEG-2 TS, o desenvolvimento de um modelo em software para o demultiplexador e de um ambiente contendo fluxos MPEG-2 TS capazes de validar a conformidade dos modelos com a especificação do SBTVD, a implementação e validação de uma prova de conceito para um demultiplexador MPEG-2 TS no nível RTL e sua prototipagem com mapeamento tecnológico para FPGA e para um design kit de ASIC.
14

Digital videoväxel / Digital video switch

Länger, Henrik, Eriksson, Olle January 2004 (has links)
<p>This thesis discusses the possibilities to distribute digital video in a military vehicle. Today, an analogue system is used, which has a maximum capacity of eighteen video sources and the same number of monitors. The purpose of this thesis is to increase the systems capabilities regarding secure distribution and additional functions. </p><p>Both software and hardware tests are made to investigate the features of the digital video standard MPEG-2. Both the coding delay and the image quality are of great interest. Another digital video standard, DV, is considered as an alternative to MPEG-2. </p><p>Apart from different coding techniques, this work describes some distribution techniques like TCP/IP, DVB-C and USB.</p>
15

Bitefficient Coding Methods for Low Bitrate MPEG-1/MPEG-2 Encoders

Johansson, Andreas January 2002 (has links)
<p>The packing and coding of digital video is a part of science where much innovation has taken place during the last few decades. The MPEG standards of video encoding are some of the most well-known and used video coding standards today. Since MPEG defines exact requirements for the decoder, but not the encoder, encoders can be made in many different ways and levels of complexity, as long as they produce legal MPEG streams that can be viewed on any MPEG-conformant decoder. This thesis will examine the possible performance of MPEG, in particular MPEG-1/MPEG-2 full TV resolution (720*576), for coding video at bitrates significantly lower than the 2-15 Mb/s MPEG-2 originally was designed for. For this purpose, encoding methods previously proposed by various researchers are presented. Furthermore a few new algorithms, which can be used for MPEG coding in general, but was constructed with a low-bitrate encoder in mind, were developed. Finally objective video quality benchmarks were conducted and the results evaluated.</p>
16

Bitefficient Coding Methods for Low Bitrate MPEG-1/MPEG-2 Encoders

Johansson, Andreas January 2002 (has links)
The packing and coding of digital video is a part of science where much innovation has taken place during the last few decades. The MPEG standards of video encoding are some of the most well-known and used video coding standards today. Since MPEG defines exact requirements for the decoder, but not the encoder, encoders can be made in many different ways and levels of complexity, as long as they produce legal MPEG streams that can be viewed on any MPEG-conformant decoder. This thesis will examine the possible performance of MPEG, in particular MPEG-1/MPEG-2 full TV resolution (720*576), for coding video at bitrates significantly lower than the 2-15 Mb/s MPEG-2 originally was designed for. For this purpose, encoding methods previously proposed by various researchers are presented. Furthermore a few new algorithms, which can be used for MPEG coding in general, but was constructed with a low-bitrate encoder in mind, were developed. Finally objective video quality benchmarks were conducted and the results evaluated.
17

A Cost Shared Quantization Algorithm and its Implementation for Multi-Standard Video CODECS

2012 December 1900 (has links)
The current trend of digital convergence creates the need for the video encoder and decoder system, known as codec in short, that should support multiple video standards on a single platform. In a modern video codec, quantization is a key unit used for video compression. In this thesis, a generalized quantization algorithm and hardware implementation is presented to compute quantized coefficient for six different video codecs including the new developing codec High Efficiency Video Coding (HEVC). HEVC, successor to H.264/MPEG-4 AVC, aims to substantially improve coding efficiency compared to AVC High Profile. The thesis presents a high performance circuit shared architecture that can perform the quantization operation for HEVC, H.264/AVC, AVS, VC-1, MPEG- 2/4 and Motion JPEG (MJPEG). Since HEVC is still in drafting stage, the architecture was designed in such a way that any final changes can be accommodated into the design. The proposed quantizer architecture is completely division free as the division operation is replaced by multiplication, shift and addition operations. The design was implemented on FPGA and later synthesized in CMOS 0.18 μm technology. The results show that the proposed design satisfies the requirement of all codecs with a maximum decoding capability of 60 fps at 187.3 MHz for Xilinx Virtex4 LX60 FPGA of a 1080p HD video. The scheme is also suitable for low-cost implementation in modern multi-codec systems.
18

Digital videoväxel / Digital video switch

Länger, Henrik, Eriksson, Olle January 2004 (has links)
This thesis discusses the possibilities to distribute digital video in a military vehicle. Today, an analogue system is used, which has a maximum capacity of eighteen video sources and the same number of monitors. The purpose of this thesis is to increase the systems capabilities regarding secure distribution and additional functions. Both software and hardware tests are made to investigate the features of the digital video standard MPEG-2. Both the coding delay and the image quality are of great interest. Another digital video standard, DV, is considered as an alternative to MPEG-2. Apart from different coding techniques, this work describes some distribution techniques like TCP/IP, DVB-C and USB.
19

Correção o de PCR em processadores de fluxos de transporte MPEG-2

Avino, Heitor Judiss 25 September 2012 (has links)
Submitted by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-02-18T18:50:03Z No. of bitstreams: 1 Dissertação - Heitor Judiss Savino.pdf: 12604505 bytes, checksum: fb1bcd22abe6766240e85da3ba2e5109 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-02-18T19:37:30Z (GMT) No. of bitstreams: 1 Dissertação - Heitor Judiss Savino.pdf: 12604505 bytes, checksum: fb1bcd22abe6766240e85da3ba2e5109 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-02-18T19:37:54Z (GMT) No. of bitstreams: 1 Dissertação - Heitor Judiss Savino.pdf: 12604505 bytes, checksum: fb1bcd22abe6766240e85da3ba2e5109 (MD5) / Made available in DSpace on 2016-02-18T19:37:54Z (GMT). No. of bitstreams: 1 Dissertação - Heitor Judiss Savino.pdf: 12604505 bytes, checksum: fb1bcd22abe6766240e85da3ba2e5109 (MD5) Previous issue date: 2012-09-25 / Não informada / Currently, the MPEG-2 transport stream is widely used as multiplexing system for sending audio, video, and data, in digital television networks. The transmitted infor- mation is divided into xed-length pa kets, whi h are multiplexed in time and then sent to the re eiver. In order to ensure the orre t presentation of data related to a given program (e.g., audio and video), the transport stream an provide time bases, whi h are used for syn hronizing the re eption system. However, that information, whi h is known as Program Clo k Referen e (PCR) and is also periodi ally embedded in the multiplexed data stream, may su er from ina ura ies, due to the pro essing hain between transmitter and re eiver, whi h an be per eived in the form of jitter. In order to prevent that errors aused by the transport stream pro essing hain, whi h ompromises the proper presentation of the transmitted information, PCR orre tion methods are normally employed. This work presents a review of the PCR orre - tion methods ommonly used in the literature and introdu es two new ontributions. The rst one onsists of a shared a ess stru ture for the orre tion blo k, whi h has the potential to provide a redu ed omputational omplexity (in terms of arithmeti operations) and hardware requirements, when used with traditional PCR orre tion methods. The se ond one devises an intelligent method for PCR orre tion, whose main feature lies on the redu tion of the jitter aused by the orre tion pro ess. Its ar hite ture is based on the ooperative operation of the main modules involved in this pro ess: the rate adapter and the PCR orre tor. In spite of presenting a higher om- plexity, its superior performan e favors the syn hronization pro ess, performed by the re eiver, whi h makes it suitable for pre ise time-bases demanding systems. The pro- posed methodologies are ombined, whi h provides a omplete and e ient framework for pro essing MPEG-2 transport streams. / Atualmente, o fluxo de transporte MPEG-2 é amplamente utilizado como chamada de transporte para a multiplexação de programas que arregam áudio, vídeo e dados, em redes de televisão digital. As informações transmitidas são divididas em pa otes de tamanho xo, multiplexadas no tempo e então enviadas ao re eptor. Para que os da- dos de um mesmo programa sejam apresentados orretamente e em sin ronismo (e.g. áudio e vídeo), o uxo de transporte permite a in orporação de bases de tempo, que são utilizadas na sin ronização do sistema de re epção. Entretanto, essa informação, onhe ida omo Program Clo k Referen e (PCR) e inserida periodi amente no feixe multiplexado, pode sofrer erros, observados na forma de jitter, devido à adeia de pro- essamento entre transmissor e re eptor. Dessa forma, para se evitar que o erro inserido pelo pro essamento do uxo de transporte prejudique a apresentação da informação enviada, métodos de orreção de PCR são geralmente utilizados. Este trabalho apre- senta um estudo sobre os métodos de orreção de PCR mais utilizados na literatura e introduz duas novas ontribuições. A primeira onsiste em uma estrutura de a esso ompartilhado para o blo o de orreção, que tem o poten ial de propor ionar ara terís- ti as reduzidas de omplexidade omputa ional (quantidade de operações aritméti as) e requisitos de hardware, quando utilizada em onjunto om métodos tradi ionais de orreção de PCR. A segunda onsiste em um método inteligente para a orreção de PCR, uja prin ipal ara terísti a é a redução do erro inserido pelo pro esso de orre- ção. A sua arquitetura é baseada na operação ooperativa dos dois prin ipais agentes envolvidos nesse pro esso: os módulos de adaptação de taxa e de orreção de PCR. Apesar de apresentar maior omplexidade omputa ional, o seu desempenho superior fa ilita o pro esso de sin ronização, exe utado pelo re eptor, o que o torna bastante adequado a sistemas que exigem bases de tempo pre isas. As metodologias propostas são utilizadas em onjunto, propor ionando um esquema integrado e e iente para o pro essamento de uxos de transporte MPEG-2.
20

A HTTP Streaming Video Server with Dynamic Advertisement Splicing

Islam, Md. Safiqul January 2010 (has links)
The Internet today is experiencing a large growth in the amount of traffic due to the number of users consuming streaming media. For both the operator and content providers, streaming of media generates most of its revenue through advertisements inserted in the content. One common approach is to pre-stitched (i.e. insert) advertisements into the content. Another approach is dynamic advertisement insertion, which inserts advertisements at run-time while the media is being streamed. Dynamic advertisement insertion gives operators the flexibility to insert advertisements based on context, such as the user's geographic location or the user's preferences. Developing a technique to successfully insert advertisements dynamically into the streaming media has several challenges, such as maintaining synchronization of the media, choosing the appropriate transport format for media delivery, and finding a splicing boundary that starts with a key frame. The details of these challenges are detailed in this thesis. We carried out extensive research to find the best transport format for delivery of media and we studied prior work in an effort to find an appropriate streaming solution to perform dynamic advertisement insertion. Based upon this research and our study of prior work we identify the best transport format for delivery of media chunks, then propose, implement, and evaluate a technique for advertisement insertion. / Idag har internet mycket trafik på grund av att alltfler servrar erbjuder högkvalitativa videon som strömmas till internetanvändare. Både för operatörer och leverantörer av sådan innehåll genererar direktuppspelning mest intäkter genom annonser som lagts till i videon. Det är väldigt vanligt att lägga till annonser i videon genom att sy in dem i videofiler. En annan metod är att lägga till annonser dynamiskt. Det betyder att resulterande videofilen genereras medan den blir strömmad till användare. Att sätta in annonser dynamiskt har som fördel för operatörer att välja reklam beroende på kontexten, såsom användarens position eller preferenser. Det är utmanande att utveckla den teknik som krävs för att kunna sätta in annonser dynamiskt i strömmade videofiler. Till exempel är det viktigt att tänka på följande: synkronisering av strömmad innehåll, val av lämplig transportformat för videoleveransen och gränsen för skarvning (så kallad splicing boundary). Detaljerna kring denna teknik finns i denna avhandling. Vi har forskat på att hitta det bästa transportformatet för videoleverans och vi har studerat relevant arbete som gjorts tidigare för att hitta en lämplig mekanism för dynamisk annonsinsättning. Baserat på vår forskning och studerande av tidigare arbeten har vi klassificerat det bästa formatet för leveransen av videostycken, implementerat och evaluerat en teknik för annonsinlägg.

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