Convergence of Real-Time Audio and Video Streaming Technologies
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Die approbierte Originalversion dieser Dissertation ist an der Hauptbibliothek der Technischen Universität Wien aufgestellt (http://www.ub.tuwien.ac.at). The approved original version of this thesis is available at the main library of the Vienna University of Technology (http://www.ub.tuwien.ac.at/englweb/). DISSERTATION Convergence of Real-time Audio and Video Streaming Technologies ausgeführt zum Zwecke der Erlangung des akademischen Grades eines Doktors der technischen Wissenschaften unter der Leitung von o. Univ. Prof. Dipl.-Ing. Dr. techn. Dietmar Dietrich, Institut für Computertechnik Technische Universität Wien und Prof. Dr. Gerhard P. Hancke Department of Electrical, Electronic and Computer Engineering University of Pretoria eingereicht an der Technischen Universität Wien Fakultät für Elektrotechnik und Informationstechnik von Dipl.-Ing. Manfred Weihs Matrikel-Nr. 9525662 Babogasse 3, 2020 Hollabrunn Wien, Oktober 2006 Kurzfassung Die digitale Vernetzung von elektronischen Geräten im Heimbereich gewinnt immer mehr an Be- deutung. In einem typischen Haus werden viele verschiedene Arten von Netzwerken installiert, die für unterschiedliche Zwecke optimiert sind. Einige davon können zur Echtzeit-Übertragung von Audio-/Video-Daten verwendet werden. Gleiches gilt für den Automobil-Bereich. Diese Arbeit beschreibt Konzepte zur Echtzeit-Übertragung von Multimedia-Daten im Heim- und Automobilbereich, geht auf die notwendigen Voraussetzungen ein und erläutert Möglichkeiten, die Grenzen zwischen verschiedenen Netzwerken zu überwinden. Aufgrund der Anzahl an verschiedenen Netzwerken in diesen Umgebungen, die auch für Audio-/Video-Streaming eingesetzt werden, kann eine Verbindung dieser Netzwerke den Nutzen der angeschlossenen Geräte erhöhen. Es werden Möglichkeiten aufgezeigt, verschiedene Netze zu koppeln, um Quellen und Senken dieser Ströme in unterschiedlichen Arten von Netzwerken zu verbinden. Das Design eines Gateways wird erarbeitet, wobei besonderer Wert darauf gelegt wird, dass dieses möglichst universell ist und an verschiedene Netzwerke und Protokolle angepasst werden kann. Das Gateway führt so geringe Modifikationen wie möglich an dem Multimedia-Datenstrom durch, sodass die Qualität der Wiedergabe möglichst wenig unter der Umsetzung zwischen den verschiedenen Netzwerken leidet. Die Datenübertragung erfolgt auf allen beteiligten Netzwerken gemäß offenen Standards, um einer maximalen Anzahl von Geräten die Teilnahme daran zu ermöglichen. Proprietäre Protokolle werden vermieden. Im Rahmen von Beispiel-Implementierungen werden Teilaspekte der Problemstellung gelöst und somit die Funktionalität des gewählten Ansatzes nachgewiesen. Spezielle Probleme, die berücksichtigt werden müssen, wie insbesondere das korrekte Zeitverhalten, werden aufgezeigt und Lösungsmöglichkeiten vorgestellt. Es wird gezeigt, wie verschiedene Netzwerke über ein universelles Gateway für Echtzeit-Multimedia-Datenströme gekoppelt werden können. ii Abstract Networking between electronic devices within the home becomes more and more common. In a typical house, there are many different kinds of network that are optimised for dedicated applications. Some can be used for real-time transmission of audio/video data. The same applies to the automotive sector. This work describes concepts for real-time transmission of multimedia data within the home and vehicles, specifies the requirements and outlines how to overcome the borders between the networks with respect to audio/video streaming. Due to the number of different networks that are used for audio and video streaming in these environments, interconnection between these networks can add benefit to the attached devices. Possibilities for coupling of different networks are examined to connect sources and sinks of these streams in various kinds of network. The design of a gateway is developed. Special attention is paid to make it as universal as possible and allow adaptation for different networks and protocols. The gateway modifies the multimedia data stream as little as possible in order to minimise the degradation of the presentation quality. Data transmission is performed according to open standards on all networks in order to enable as many devices as possible to take part. Proprietary protocols are avoided. Example implementations demonstrate the solutions to different parts of the problem and prove the functionality of the chosen concept. Special problems that have to be carefully con- sidered, particularly timing issues, are explained, and solutions are proposed. It is shown how different networks can be coupled via a universal gateway for real-time multimedia streaming. iii Preface Multimedia streaming and the IEEE 1394 bus (FireWire) have been one of my major fields of interest already during my diploma studies. My diploma thesis was about reception of digital TV programs as MPEG-2 transport streams over IEEE1394, decoding them in software and presenting them on an ordinary PC. So I have been in touch with all the protocols involved in real-time transmission of audio and video on IEEE 1394 since the year 2000. After finishing my diploma studies, I became member of the Institute of Computer Technology (ICT) of Vienna University of Technology. During my first year at the ICT, I was involved in the EU funded project InHoMNet, in which a home network concept based on IEEE1394 was developed. The task of the team at the ICT was to develop an intelligent external tuner receiving digital TV via satellite and transmitting it on IEEE 1394. In particular, the hardware of the system and the software for a HAVi protocol stack had to be developed. At this time I already realised that real-time streaming of multimedia in home networks is a very interesting research topic. IEEE 1394 would not be the only network in the home that comprises sources and sinks of multimedia data. So it became obvious that coupling of different networks could add a significant benefit for the users. As it turned out, relaying a real-time multimedia data stream from one network into another one causes a bunch of unsolved problem, especially with regard to correct timing. This was my motivation to study this topic in-depth and start writing my dissertation about it. After the InHoMNet project, I founded the spin-off company “dmn Software-Entwicklung GmbH” together with four colleagues, which focused in developing and marketing of a HAVi protocol stack used for control of audio and video devices on an IEEE1394 bus. I also got involved into a second EU funded project called HOME-PLANET. We had to provide the HAVi stack and a graphical user interface. In addition, we had to manage streaming connections on IEEE 1394 and decode received audio/video streams. So I stayed in touch with multimedia streaming and, in particular, the protocols used on IEEE 1394 throughout my employment at the ICT and could use many results for this dissertation. I want to thank the head of ICT, Prof. Dietmar Dietrich, not only for giving me the op- portunity to work and perform my doctoral studies at this institute, but also for support and advice concerning this thesis. I thank him and Prof. Gerhard P. Hancke from University of Pretoria for reviewing this dissertation. I have to express my gratitude to the members of the former “IEEE 1394 multimedia group” at the ICT. Together with Peter Skiczuk, who shared my room for several years and gave me an excellent working atmosphere, Michael Ziehensack, Christian Gillesberger, and René Bauer, I had the pleasure to be part of a very good team. We had many interesting discussions, did efficient and good development, and we founded the company “dmn Software-Entwicklung GmbH”. I also have to thank the members of the teams at the ICT I joined after the IEEE 1394 multi- media group had been closed, specifically Peter Palensky, Brigitte Lorenz, Maxim Lobashov, and Friederich Kupzog. All of them gave me valuable suggestions for this dissertation, regarding content, formal aspects, or procedure, and formed teams I enjoyed to be part of. iv Special thanks go to Patrick Loschmidt. We already did most of our diploma studies together, and also during the doctoral studies, he always gave me advice when it was needed. I am indebted to him for proof-reading major parts of this work. I am grateful to all my students who did their diploma theses or practical courses under my supervision. Some results were valuable input for the work on this dissertation. Last, but not least, I express my sincere thanks to my family, in particular to my parents, for supporting me and providing me an environment in which academic studies can be carried out. v Contents 1 Introduction 1 1.1 Kinds of Multimedia Streaming . 2 1.2 ProblemDescription ................................. 4 2 Network Requirements for Real-time Multimedia Streaming 7 2.1 QualityofService................................... 7 2.2 ResourceManagement ............................... 10 2.3 Multicast ....................................... 12 2.4 EnvironmentalRequirements . .. 13 3 State of the Art 14 3.1 DataTypesandFormats.............................. 14 3.1.1 AudioPCM.................................. 14 3.1.2 FLAC and Other Lossless Audio Codecs . 15 3.1.3 CELP,Speex,GSMandOtherSpeechCodecs. 16 3.1.4 MPEGAudioandVorbis .......................... 16 3.1.5 VideoUncompressed............................. 18 3.1.6 M-JPEG,DV................................. 19 3.1.7 MPEGCompressedVideo.......................... 20 3.1.8 ITU Recommendations H.261, H.262, H.263, H.264 . 23 3.1.9 MultiplexStreams .............................