1. M P E G A Presentation by Sebastian Graf and Thomas Winterscheid

2. Topics What is MPEG? Different MPEG Standards What is a movie? The MPEG video compression Conclusion

3. What is MPEG?

4. What is MPEG exactly? „Moving Picture Experts Group“ Established in 1988 The convener of the MPEG group is Dr. Leonardo Chiariglione Vice president of Multimedia Telecom Italia Lab http://leonardo.telecomitalialab.com/

5. What is MPEG exactly? Comission directed by ISO an IEC Develops standards for video and audio coding Nickname given to a family of international standards

6. Approved MPEG Standards MPEG-1 Nov. `92 MPEG-2 Nov. `94 MPEG-4 Version 1 Oct. `98 Version 2 Dec `99

7. Planned for the future... MPEG-4 Version 3,4 and 5 MPEG-7 MPEG-21

8. MPEG-1 Quality ~ VHS – video Originally for 1x CD-ROM drives (1,4 MBit/s) Constant datarate Standard for Video CDs

9. MPEG-2 HDTV (High Definition TeleVision) Premiere World (lower rates for more chan.) Still important for new digital TV norms DVD Variable datarates

10. MPEG-3 ? MPEG-3 standard was under construction, but never finished Was planned for newer HDTV Parts of technology and techniques are implemented in MPEG-2

11. Overview 1,4 Mbit/325x288 High Compression Audiocodec Assymetric compression Only in SIF Format Codec for Multimedia files on your PC 4 Mbit/325x288 15 Mbit/720x576 60 Mbit/1440x1152 80 Mbit/1920x1152 Different Formats Supports Dolby Surround Much more complicated as MPEG-1 Multimedia PC Digital TV Satellite TV MPEG-1 MPEG-2 Datarate/ Resolution AdvantagesDisadvantages Scope

12. The Future: MPEG-7 Planned to be released in fall 2001 Is formally called „Multimedia Content Description Interface“ Includes a new standard of handling DDL More easier to implement into multimedia Intends to be an allrounder for all multimedia formats

13. The Future: MPEG-7 MPEG 1-2-4 won`t be replaced by MPEG-7 Works indepentend of it`s predecessors Because of file description data query in special multimedia databank is possible Several search options will be included But this isn`t enough................

14. More Future: MPEG-21 Development is running, planned to be finished in 2003 Includes a new description language (DIDL) Universal player for all standards Multimedia files are more communicative And also there is to say...............

15. More Future: MPEG-21 The general goal of MPEG-21 activities is to describe an open framework which allows the integration of all components of a delivery chain necessary to generate, use, manipulate, manage, and deliver multimedia content across a wide range of networks and devices.http://ipsi.fhg.de/delite/Projects/MPEG7/Mpeg21.html

16. Topics What is MPEG? Different MPEG Standards What is a movie? The MPEG video compression Conclusion

17. What is a movie? video track audio track timecode

18. What is a movie? timecode

19. encode or decode? encoderdecoder 100111010011

20. MPEG video compression movie picture 1movie picture 2

21. MPEG video compression High similarity of 2 successive pictures => correlation Same pixel´s movement in Camera turns =>motion compensation DCT & quantization

22. MPEG video compression

23. The block layer Picture is divided in 8x8 blocks (JPEG) The blocks are processed independent from each other DCT Quantization

24. DCT & Quantization Very similar to the fourier transformation Information are transformed to a frequenz- exhibition (nearly no data loss) Matrix of DCT-coefficients Coefficients are divided by quantization values (given by the JPEG group) and then rounded to the next integer value

25. Discrete Cosinus Transformation 50 100 150 200 0 0 50 100 150 200 250 0 50 100 150 200 250 -503 -314 -125 65

26. The macro layer I – Frame, P – Frame or B – Frame?

27. The macro layer I – Frames: „intra coded image“ highest amount of data coding is very similar to a JPEG picture can be processed independent from other frames have a specified distance to the next I-Frame

28. The macro layer B – Frames: „bi-directionally interpolated image“ lowest amount of data most frequent type of frame depending on the previous or following P / I-Frame can also depend on the previous and following frame

29. The macro layer P – Frames: „predicted image“ medium amount of data difference to the previous I – Frame is stored have motion compensation ability

30. The macro layer Motion Compensation in P – Frames : I - FrameP - Frame

31. The slice layer Slices are a group of succesive macro- blocks There is no dependence of slices on each other

32. The picture layer IBBPBBP IPBBPBB Display Datastream

33. The „group of picture“ layer Unrestricted number of pictures in their natural sequence At least one I-Frame per GOP Quantization values can be different for each GOP

34. The sequence layer Union of GOPs Movie width Movie height Movie format (e.g. 4:3 / 16:9) Framerate (fps) Bit-rate

35. Conclusion MPEG is a very common standard Look forward to the new codec technologies Contains numerous new features New standards will be much more user friendly Many options to adjust the compression Even better techniques for even better quality

36. Any questions? leonardo.chiariglione@tilab.com

37. Thanks for your attention...