This thesis reports original work on hardware realization of symmetric video encryption using chaos-based continuous systems as pseudo-random number generators. The thesis also presents some of the serious degradations caused by digitally implementing chaotic systems. Subsequently, some techniques to eliminate such defects, including the ultimately adopted scheme are listed and explained in detail. Moreover, the thesis describes original work on the design of an encryption system to encrypt MPEG-2 video streams. Information about the MPEG-2 standard that fits this design context is presented. Then, the security of the proposed system is exhaustively analyzed and the performance is compared with other reported systems, showing superiority in performance and security. The thesis focuses more on the hardware and the circuit aspect of the system’s design. The system is realized on Xilinx Vetrix-4 FPGA with hardware parameters and throughput performance surpassing conventional encryption systems.

Gemeinsamer Workshop von Universitaetsrechenzentrum und Professur Rechnernetze und verteilte Systeme (Fakultaet fuer Informatik) der TU Chemnitz. Workshop-Thema: Infrastruktur der ¨Digitalen Universitaet¨

No transporte de vídeo e áudio para aplicações de TV digital com recepção em terminais móveis podem ser utilizadas redes de distribuição de conteúdo baseadas em pacotes. Essas redes tornam o transporte dos sinais mais flexível. Entretanto, podem adicionar atrasos e variações de atraso, prejudicando o sincronismo dos fluxos de informação e, conseqüentemente, a apresentação das mídias. Nesta dissertação foi proposto um framework para avaliação e testes de sincronismo, desenvolvido para estudar a influência das perturbações causadas por redes de dados ou por remultiplexações no sincronismo de programas MPEG2. O framework possibilita o controle dos parâmetros de QoS da rede de distribuição utilizada para transmitir pacotes de um fluxo de transporte (MPEG2 Transport Stream) e permite avaliar a influência desses parâmetros no sincronismo do fluxo. Adicionalmente, foram implementados mecanismos de ressincronização do fluxo de transporte no framework, de forma a minimizar os efeitos dessas perturbações na rede. Verificou-se que os métodos implementados reduzem os efeitos de variações de atraso da rede e ressincronizam o fluxo de transporte transmitido, de forma que a variação de atraso nas amostras da referência de tempo do fluxo (Program Clock Reference . PCR) volta aos níveis anteriores (sem aplicação de variação de atraso na rede). / Content distribution packet networks can be used in video and audio transport for TV applications with reception in mobile terminals. These networks make signal transport more flexible. Nevertheless, they may add delay and jitter, damaging the synchronism of the information streams and, consequently, the media presentation. In this dissertation, a framework was proposed for synchronism test and evaluation. It was developed to study the influence of disturbances caused by data networks or remultiplexations in the synchronism of MPEG2 programs. The framework enables the control of QoS parameters of the distribution network used to transmit packets from a MPEG2 transport stream and allows the evaluation of the influence of these parameters in the synchronism of the streams. Furthermore, transport stream resynchronization mechanisms were implemented in the framework, minimizing the effects of these disturbances in the network. It was observed that the methods implemented reduce the effects of jitter in the network and resynchronize the transport stream transmitted, in a way that the jitter in the time reference samples (Program Clock Reference . PCR) of the stream returns to previous levels (without applying jitter in the network).

No transporte de vídeo e áudio para aplicações de TV digital com recepção em terminais móveis podem ser utilizadas redes de distribuição de conteúdo baseadas em pacotes. Essas redes tornam o transporte dos sinais mais flexível. Entretanto, podem adicionar atrasos e variações de atraso, prejudicando o sincronismo dos fluxos de informação e, conseqüentemente, a apresentação das mídias. Nesta dissertação foi proposto um framework para avaliação e testes de sincronismo, desenvolvido para estudar a influência das perturbações causadas por redes de dados ou por remultiplexações no sincronismo de programas MPEG2. O framework possibilita o controle dos parâmetros de QoS da rede de distribuição utilizada para transmitir pacotes de um fluxo de transporte (MPEG2 Transport Stream) e permite avaliar a influência desses parâmetros no sincronismo do fluxo. Adicionalmente, foram implementados mecanismos de ressincronização do fluxo de transporte no framework, de forma a minimizar os efeitos dessas perturbações na rede. Verificou-se que os métodos implementados reduzem os efeitos de variações de atraso da rede e ressincronizam o fluxo de transporte transmitido, de forma que a variação de atraso nas amostras da referência de tempo do fluxo (Program Clock Reference . PCR) volta aos níveis anteriores (sem aplicação de variação de atraso na rede). / Content distribution packet networks can be used in video and audio transport for TV applications with reception in mobile terminals. These networks make signal transport more flexible. Nevertheless, they may add delay and jitter, damaging the synchronism of the information streams and, consequently, the media presentation. In this dissertation, a framework was proposed for synchronism test and evaluation. It was developed to study the influence of disturbances caused by data networks or remultiplexations in the synchronism of MPEG2 programs. The framework enables the control of QoS parameters of the distribution network used to transmit packets from a MPEG2 transport stream and allows the evaluation of the influence of these parameters in the synchronism of the streams. Furthermore, transport stream resynchronization mechanisms were implemented in the framework, minimizing the effects of these disturbances in the network. It was observed that the methods implemented reduce the effects of jitter in the network and resynchronize the transport stream transmitted, in a way that the jitter in the time reference samples (Program Clock Reference . PCR) of the stream returns to previous levels (without applying jitter in the network).

Gemeinsamer Workshop von Universitaetsrechenzentrum und Professur Rechnernetze und verteilte Systeme (Fakultaet fuer Informatik) der TU Chemnitz. Workshop-Thema: Infrastruktur der ¨Digitalen Universitaet¨

Error Correction and Concealment of Block Based, Motion-Compensated Temporal Prediction, Transform Coded Video David L. Robie 133 Pages Directed by Dr. Russell M. Mersereau The use of the Internet and wireless networks to bring multimedia to the consumer continues to expand. The transmission of these products is always subject to corruption due to errors such as bit errors or lost and ill-timed packets; however, in many cases, such as real time video transmission, retransmission request (ARQ) is not practical. Therefore receivers must be capable of recovering from corrupted data. Errors can be mitigated using forward error correction in the encoder or error concealment techniques in the decoder. This thesis investigates the use of forward error correction (FEC) techniques in the encoder and error concealment in the decoder in block-based, motion-compensated, temporal prediction, transform codecs. It will show improvement over standard FEC applications and improvements in error concealment relative to the Motion Picture Experts Group (MPEG) standard. To this end, this dissertation will describe the following contributions and proofs-of-concept in the area of error concealment and correction in block-based video transmission. A temporal error concealment algorithm which uses motion-compensated macroblocks from previous frames. A spatial error concealment algorithm which uses the Hough transform to detect edges in both foreground and background colors and using directional interpolation or directional filtering to provide improved edge reproduction. A codec which uses data hiding to transmit error correction information. An enhanced codec which builds upon the last by improving the performance of the codec in the error-free environment while maintaining excellent error recovery capabilities. A method to allocate Reed-Solomon (R-S) packet-based forward error correction that will decrease distortion (using a PSNR metric) at the receiver compared to standard FEC techniques. Finally, under the constraints of a constant bit rate, the tradeoff between traditional R-S FEC and alternate forward concealment information (FCI) is evaluated. Each of these developments is compared and contrasted to state of the art techniques and are able to show improvements using widely accepted metrics. The dissertation concludes with a discussion of future work.

<p>The progression of technical development has yielded practicable camera systems for the acquisition of so called depth maps, images with depth information. </p><p>Images and movies with depth information open the door for new types of applications in the area of computer graphics and vision. That implies that they will need to be processed in all increasing volumes.</p><p>Increased depth image processing puts forth the demand for a standardized data format for the exchange of image data with depth information, both still and animated. Software to convert acquired depth data to such videoformats is highly necessary. </p><p>This diploma thesis sheds light on many of the issues that come with this new task group. It spans from data acquisition over readily available software for the data encoding to possible future applications. </p><p>Further, a software architecture fulfilling all of the mentioned demands is presented. </p><p>The encoder is comprised of a collection of UNIX programs that generate MPEG Z/Alpha, an MPEG2 based video format. MPEG Z/Alpha contains beside MPEG2's standard data streams one extra data stream to store image depth information (and transparency). </p><p>The decoder suite, called TexMPEG, is a C library for the in-memory decompression of MPEG Z/Alpha. Much effort has been put into video decoder parallelization, and TexMPEG is now capable of decoding multiple video streams, not only in parallel internally, but also with inherent frame synchronization between parallely decoded MPEG videos.</p>

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.

The progression of technical development has yielded practicable camera systems for the acquisition of so called depth maps, images with depth information. Images and movies with depth information open the door for new types of applications in the area of computer graphics and vision. That implies that they will need to be processed in all increasing volumes. Increased depth image processing puts forth the demand for a standardized data format for the exchange of image data with depth information, both still and animated. Software to convert acquired depth data to such videoformats is highly necessary. This diploma thesis sheds light on many of the issues that come with this new task group. It spans from data acquisition over readily available software for the data encoding to possible future applications. Further, a software architecture fulfilling all of the mentioned demands is presented. The encoder is comprised of a collection of UNIX programs that generate MPEG Z/Alpha, an MPEG2 based video format. MPEG Z/Alpha contains beside MPEG2's standard data streams one extra data stream to store image depth information (and transparency). The decoder suite, called TexMPEG, is a C library for the in-memory decompression of MPEG Z/Alpha. Much effort has been put into video decoder parallelization, and TexMPEG is now capable of decoding multiple video streams, not only in parallel internally, but also with inherent frame synchronization between parallely decoded MPEG videos.

This master’s theses consists of theoretical introduction which includes basic search of referenced literature about digital television systems and picture quality classification. The results of signal character measurement of selected TV channels from satellites ASTRA 1E (DVB-S) and ASTRA 1L (DVB-S2) are provided. The energy budget calculation of downlink and results of 24-hour TS error rate measurement is included as well. The video quality by DVQL metric for each particular program of CS link stream was measured during full 24 hours.