A Guide to MPEG Fundamentals and Protocol Analysis

1 mpeg TutorialA Guide to mpeg Fundamentals and Protocol Analysis (Including DVB and ATSC)A Guide to mpeg Fundamentalsand Protocol Analysis (Including DVB and ATSC)iiA Guide to mpeg Fundamentals and Protocol Guide to mpeg Fundamentals and Protocol 1 Introduction to mpeg Convergence Why Compression is Needed Applications of Compression Introduction to Video Compression Introduction to Audio Compression mpeg Signals Need for

2 Monitoring and Analysis Pitfalls of Compression 6 Section 2 Compression in Video Spatial or Temporal Coding? Spatial Coding Weighting Scanning Entropy Coding A Spatial Coder Temporal Coding Motion Compensation

3 Bidirectional Coding I, P, and B Pictures An mpeg Compressor Preprocessing Profiles and Levels Wavelets 22 Section 3 Audio Compression The Hearing Mechanism Subband Coding

4 mpeg Layer 1 mpeg Layer 2 Transform Coding mpeg Layer 3 AC-3 27 Section 4 Elementary Streams Video Elementary Stream Syntax Audio Elementary Streams 30 Contents A Guide to mpeg Fundamentals and Protocol AnalysisivSection 5 Packetized Elementary Streams (PES) PES Packets Time Stamps PTS/DTS 31 Section 6 Program Streams Recording vs.

5 Transmission Introduction to Program Streams 33 Section 7 Transport Streams The Job of a Transport Stream Packets Program Clock Reference (PCR) Packet Identification (PID) Program Specific Information (PSI) 37 Section 8 Introduction to DVB/ATSC An Overall View Remultiplexing Service Information (SI)

6 Error Correction Channel Coding Inner Coding Transmitting Digits 44 Section 9 mpeg Testing Testing Requirements Analyzing a Transport Stream Hierarchic View Interpreted View Syntax and CRC Analysis Filtering Timing Analysis Elementary Stream Testing Sarnoff Compliant Bit Streams Elementary Stream Analysis

7 Creating a Transport Stream Jitter Generation DVB Tests 53 Glossary 55A Guide to mpeg Fundamentals and Protocol Guide to mpeg Fundamentals and Protocol is one of the most popular audio/video compression techniques becauseit is not just a single standard. Instead, it is a range of standards suitable fordifferent applications but based on similar principles. mpeg is an acronym forthe Moving Picture Experts Group which was set up by the ISO (InternationalStandards Organization) to work on can be described as the interaction of acronyms.

8 As ETSI stated TheCAT is a pointer to enable the IRD to find the EMMs associated with the CAsystem(s) that it uses. If you can understand that sentence you don t need thisbook! ConvergenceDigital techniques have made rapid progress in audio and video for a numberof reasons. Digital information is more robust and can be coded to substantiallyeliminate error. This means that generation-loss in recording and losses intransmission are eliminated. The Compact Disc was the first consumer productto demonstrate the CD has an improved sound quality with respect to its vinyl predeces-sor, comparison of quality alone misses the point. The real point is that digitalrecording and transmission techniques allow content manipulation to a degreethat is impossible with analog. Once audio or video are digitized, they becomedata. Such data cannot be distinguished from any other kind of data; therefore,digital video and audio become the province of computer convergence of computers and audio/video is an inevitable consequence ofthe key inventions of computing and Pulse Code Modulation.

9 Digital media canstore any type of information, so it is easy to use a computer storage device fordigital video. The nonlinear workstation was the first example of an applicationof convergent technology that did not have an analog forerunner. Anotherexample, multimedia, mixed the storage of audio, video, graphics, text, anddata on the same medium. Multimedia is impossible in the analog Why Compression is NeededThe initial success of digital video was in post-production applications, wherethe high cost of digital video was offset by its limitless layering and effectscapability. However, production-standard digital video generates over 200megabits per second of data and this bit rate requires extensive capacity forstorage and wide bandwidth for transmission. Digital video could only be usedin wider applications if the storage and bandwidth requirements could beeased; easing these requirements is the purpose of is a way of expressing digital audio and video by using less has the following advantages:A smaller amount of storage is needed for a given amount of source high-density recording such as with tape, compression allows highly minia-turized equipment for consumer and Electronic News Gathering (ENG) use.

10 Theaccess time of tape improves with compression because less tape needs to beshuttled to skip over a given amount of program. With expensive storage mediasuch as RAM, compression makes new applications working in real time, compression reduces the bandwidth , compression allows faster-than-real-time transfer between media,for example, between tape and compressed recording format can afford a lower recording density and this canmake the recorder less sensitive to environmental factors and Applications of CompressionCompression has a long association with television. Interlace is a simple formof compression giving a 2:1 reduction in bandwidth. The use of color-differencesignals instead of GBR is another form of compression. Because the eye is lesssensitive to color detail, the color-difference signals need less bandwidth. Whencolor broadcasting was introduced, the channel structure of monochrome hadto be retained and composite video was developed.