Multimedia networking
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The document discusses multimedia networking, defining multimedia and networked multimedia, and outlining important components such as data compression, quality of service, bandwidth, and interoperability. It categorizes multimedia applications into real-time and non-real-time types and emphasizes the critical requirements for successful multimedia communication. The document concludes by highlighting the challenges faced in current internet multimedia applications and references related literature.
![References
• Bloch, Pigneur, and Segev (1996). On the Road of
Electronic Commerce: a Business Value Framework,
Gaining Competitive Advantage and Some Research
Issues.
http://pages.stern.nyu.edu/~mbloch/docs/roadtoec/ec.ht
m [Accessed 22 June 2002].
• Clarke, R. (2000). Roger Clarke's Electronic Commerce
Pages.
http://www.anu.edu.au/people/Roger.Clarke/EC/.
[Accessed 22 June 2002]
Dr. Hamdan M. Al-Sabri, CCIS-KSU](https://image.slidesharecdn.com/multimedianetworking-170928185709/85/Multimedia-networking-42-320.jpg)
Multimedia networking
- 1. Multimedia Networking Dr. Hamdan M. AL-Sabri King Saud University College of Computer and Information Sciences Department of Information Systems
- 2. outlines • Introduction • What is the multimedia • Various Media Types • Networked Multimedia • Major Components of Multimedia Networking • Application of Multimedia Networking(Wimax) • Summery • References Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 3. Introduction • The term ‘multimedia’ refers to diverse classes of media employed to represent information. • The term ‘Networked Multimedia’ refers to the transmission and distribution of multimedia information on the network Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 4. Characteristics of multimedia • Digital – key concept • Integration of multiple media type, usually including video or/and audio • May be interactive or non-interactive Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 5. Multimedia Classification • Real Time: Require bounds on end-to-end packet delay & jitter. Subdivided into: • Discrete Media: MSN/Yahoo Messenger, Stock quotes • Continuous Media: Continuous message stream with inter-message dependency. Further divided into: • Delay Tolerant e.g Internet webcast • Delay Intolerant e.g. audio, video streams in conferencing systems • Non-Real Time: No strict delay constraints (e.g. text, image files) • May be highly sensitive to errors Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 6. Classification of Media Type Sound Video Image Animation Text Graphics Captured From real world Synthesized By computer Discrete Discrete Continuous Continuous Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 7. Key Components of Multimedia • Modality • Channel of communication • Medium Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 8. Modality • Modality: one of the sensory systems available to human beings • The five modalities include: Sense organSensoryModality SkinTouchingTactile TongueTastingGustatory EyesSeeingVisual EarsHearingAuditory NoseSmellingOlfactory Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 9. Channel of Communication (CoC) • Definition: A connection between an encoder and decoder such that information is encoded by the encoder, transmitted along the channel and decoded by the decoder to produce the same information at the other end of the channel. • There are various types of channels of communication • A channel of communication exists within a single modality, but one modality may include many channels of communication. Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 10. Medium • Medium: A set of co-ordinated channels spanning one or more modality which have come, by convention, to be referred to as a unitary whole, and which possess a cross-channel language of interpretation. • Examples: Television A book A radio A newspaper Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 11. Multimedia Requirements • Guarantees • Throughput and/or delay guarantees • Audio requires loss/delay guarantees • Interactive apps. require low delay • CBR & VBR • Variable bit rate places extra burden Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 12. Networked Multimedia • Local vs. networked multimedia • Local: storage and presentation of multimedia information in standalone computers • Sample applications: DVD • Networked: involve transmission and distribution of multimedia information on the network • Sample applications: videoconferencing, web video broadcasting, multimedia Email, etc. Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 13. Networked Multimedia Image server Internet Video server A scenario of multimedia networking Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 14. Major Components of Multimedia Networking 1. Data compression. 2. Quality of service . 3. Bandwidth. 4. Interoperability of the network. Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 15. Data compression • Can Multimedia Data Be Compressed? • The data compression (source encoding) of multimedia data sources (e.g., speech, audio, image, and video). For different end terminals to be able to decode a compressed bit stream, international standards for these data compression schemes have to be introduced for interoperability. Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 16. Quality of service • The second major component of multimedia networking, quality of service(QoS) issues which include packet delay, packet loss, jitter, etc. These issues can be dealt with either from the network infrastructure or from an application level Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 17. Bandwidth • In ensuring the effective dissemination of compressed multimedia data over IP-based wireless broadband networks, the main challenges result from the integration of wired and wireless heterogeneous networking systems; in the latter the QoS is further degraded by the dynamically changing end-to-end available bandwidth caused by the wireless fading or shadowing and link adaptation. Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 18. Interoperability of the network • The fourth major component of multimedia networking consists of ensuring that the multimedia- networked content is fully interoperable, with ease of management and standardized multimedia content adapted for interoperable delivery, as well as intellectual property management and protection (i.e., digital rights management, DRM), effectively incorporated in the system Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 19. Multimedia Applications • Video-on-demand • Near-video-on-demand • Travel/training videos • Interactive games • Teleconferencing • IP Telephony Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 20. Multimedia Networking Systems • Live media transmission system • Capture, compress, and transmit the media. • Send stored media across the network • Media is pre-compressed and stored at the server. This system delivers the stored media to one or multiple receivers. • Differences between the two systems • For live media delivery: • Real-time media capture, need hardware support • Real-time compression– speed is important • Compression procedure can be adjusted based on network conditions • For stored media delivery • Offline compression – better compression result is important • Compression can not be adjusted during transmission Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 21. MM Networking Applications Classes of MM applications: 1) Streaming stored audio and video 2) Streaming live audio and video 3) Real-time interactive audio and video Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 22. Streaming stored audio and video • audio or video stored in file • files transferred as HTTP object • received in entirety at client • then passed to player Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 23. Streaming Live Multimedia Examples: • Internet radio talk show • Live sporting event Streaming • playback buffer • playback can lag tens of seconds after transmission • still have timing constraint Interactivity • fast forward impossible • rewind, pause possible! Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 24. Example: Streaming Live Multimedia • How to stream to large numbers of clients? • Example: A popular sporting event • Use multicast/broadcast • What about client heterogeneity? • E.g., clients might have different available b/w • Use layered/scalable video Internet Video Server ADSL Dial-up High-speed AccessDr. Hamdan M. Al-Sabri, CCIS-KSU
- 25. Real-time interactive audio and video applications: IP telephony, video conference, distributed interactive worlds • end-end delay requirements: • audio: < 150 msec good, < 400 msec OK • includes application-level (packetization) and network delays • higher delays noticeable, impair interactivity • session initialization • how does callee advertise its IP address, port number, encoding algorithms? Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 26. Multimedia &Protocols :TCP vs. UDP • TCP • No loss • Retransmits all lost messages • Potentially large latency • UDP • Potentially unbounded loss • Does no retransmission • Minimal latency Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 27. Multimedia Delivery • Even when using UDP, applications should respond to congestion end-to-end. • Need to promote “nice” behavior or “TCP-friendly” behavior. • Emerging applications shouldn’t kill the performance of “nice” applications. Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 28. Solution: A Selective Retransmission Protocol • Balances the extremes of TCP and UDP • Tradeoff between loss and latency • Retransmits a percentage of lost packets • If end-to-end delay is large, may accept loss • If end-to-end delay is small, may always request retransmission • If loss rate is very high, may request retransmission • How to decide? Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 29. Sample SRP Session Data Block Time Client Server Request retransmission (Sequence Numbers) Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 30. QoS Infrastructure to Support Multimedia Communications • Principles • Policing • Scheduling • RSVP • Integrated and Differentiated Services Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 31. Components of Interactive Multimedia • Asset – an object which encapsulates a single piece of ‘media’ (e.g. video, sound clip, graphic) • Information – the collection of data by a particular encoding • Knowledge – the interpretation and understanding of information Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 32. Relationship between the Internet, Libraries and Multimedia Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 33. Internet Multimedia: bag of tricks • use UDP to avoid TCP congestion control (delays) for time-sensitive traffic • client-side adaptive playout delay: to compensate for delay • server side matches stream bandwidth to available client- to-server path bandwidth • chose among pre-encoded stream rates • dynamic server encoding rate • error recovery (on top of UDP) • FEC, interleaving • retransmissions, time permitting • conceal errors: repeat nearby dataDr. Hamdan M. Al-Sabri, CCIS-KSU
- 34. Multimedia on the Internet • The Media Player • Streaming through the Web • The Internet Phone Example Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 35. The Media Player • End-host application • Real Player, Windows Media Player • Needs to be pretty smart • Decompression (MPEG) • Jitter-removal (Buffering) • Error correction (Repair) • GUI with controls (HCI issues) • Volume, pause/play, sliders for jumpsDr. Hamdan M. Al-Sabri, CCIS-KSU
- 36. Streaming through a Web Browser Must download whole file first! Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 37. Streaming through a Plug-In Must still use TCP! Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 38. Challenges to the Current Internet • TCP/UDP/IP suite provides best-effort, no guarantees on expectation or variance of packet delay • Streaming applications delay of 5 to 10 seconds is typical and has been acceptable, but performance deteriorate if links are congested (transoceanic) • Real-Time Interactive requirements on delay and its jitter have been satisfied by over-provisioning (providing plenty of bandwidth), what will happen when the load increases?... Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 39. Challenges to the Current Internet • Most router implementations use only First-Come-First- Serve (FCFS) packet processing and transmission scheduling • To mitigate impact of “best-effort” protocols, we can: • Use UDP to avoid TCP and its slow-start phase… • Buffer content at client and control playback to remedy jitter • Adapt compression level to available bandwidth Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 40. Multimedia & Security • Integrity • Authenticity • Encryption • Intellectual rights protection • Digital watermarking techniques embed extra information into multimedia data • Imperceptible to normal user and irremovable Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 41. Summery • Multimedia is everywhere • multimedia applications and requirements • making the best of today’s best effort service • scheduling and policing mechanisms • next generation Internet: Intserv, RSVP, Diffserv • Exciting, industry relevant research topic • Multimedia is everywhereDr. Hamdan M. Al-Sabri, CCIS-KSU
- 42. References • Bloch, Pigneur, and Segev (1996). On the Road of Electronic Commerce: a Business Value Framework, Gaining Competitive Advantage and Some Research Issues. http://pages.stern.nyu.edu/~mbloch/docs/roadtoec/ec.ht m [Accessed 22 June 2002]. • Clarke, R. (2000). Roger Clarke's Electronic Commerce Pages. http://www.anu.edu.au/people/Roger.Clarke/EC/. [Accessed 22 June 2002] Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 43. References • Elsom-Cook, M. (2001). Principles of Interactive Multimedia. New York; London : McGraw-Hill. • http://sunsite.berkeley.edu/ARL/definition.html • Philip A. Chou, Mihaela van der Schaar University of California, Los Angeles, MULTIMEDIA OVER IP AND WIRELESS NETWORKS COMPRESSION, NETWORKING, AND SYSTEMS • Computer Networking: A Top Down Approach Featuring the Internet, 3rd edition. Jim Kurose, Keith Ross Addison-Wesley, July 2004. : Multimedia Networking Dr. Hamdan M. Al-Sabri, CCIS-KSU
- 44. References • Shashank Khanvilkar, Faisal Bashir, Dan Schonfeld, and Ashfaq Khokhar • Mike Piecuch, Ken French, George Oprica and Mark Claypool,Computer Science Department,Worcester Polytechnic Institute,Proceedings of SPIE Multimedia, Systems and Applications Conference Boston, November 2000 • Dr. Hamdan M. Al-Sabri, CCIS-KSU