EBU • UER - Technical Review

EBU Technical Review : No. 281 (Autumn 1999)

Video coding

This book gives a clear and concise description of the techniques employed in digital video coding.

After an introductory chapter giving a brief history of video coding developments, Chapter 2 explains the basics of digital video signals. Digital video coding/decoding is basically a method of transforming component analogue video into a sequence of binary digits and vice versa. In fact, as Professor Ghanbari points out, 2/1 interlace is an analogue compression system which halves the required analogue bandwidth at the expense of reduced vertical resolution in the presence of vertical movement.

The derivation of CCIR-601 (nowadays called ITU-R Recommendation BT.601) is explained, since it defines the uncompressed digital video signal for standard television signals. Professor Ghanbari explains how the same bit-rate for 525-line and 625-line signals was achieved.

Chapter 3 provides a clear and concise explanation of the techniques employed to remove spatial, temporal, and statistical redundancy from the uncompressed digital video signal.

The following chapters are devoted to video compression standards that are used for various purposes, namely JPEG for high quality stills and some studio video systems, H.261 for video conferencing, MPEG-1 for medium-quality video transmission, MPEG-2 for professional-quality video transmission, plus the low bit-rate system H.263, object-orientated MPEG-4, and MPEG-7 for metadata and video indexing.

Scalability, which makes MPEG-2 flexible and future-proof, is especially well explained, probably because Professor Ghambari was involved in the development of this feature.

In conclusion, Professor Ghanbari's book provides an accurate and comprehensive introduction to video coding principles and the diverse standardized coding systems which are used for various applications.

This book can be recommended to television engineering students and to "analogue-trained" television engineers who need to update their know-how.

Video coding: an introduction to standard codecs
(IEE Telecommunications Series 42)
M. Ghanbari
Hardbound volume of 260 pages
The Institution of Electrical Engineers, UK, 1999
Ref: ISBN:0 85296 762 4. Price £39.00.

Brian Flowers

Speech and audio signal processing

This book covers a specialist area which is probably not of direct interest to the average broadcast engineer working the moment. However, audio coding systems based on analysis and synthezis of sounds, particularly speech, are already beginning to be used in specialist broadcast systems. Examples include traffic announcements that are language-independent and audio descriptors for the visually impaired.

The book is based on postgraduate courses and starts with a general introduction and historical background, starting from the work of pioneers whose technology could not match their theoretical concepts.

The book contains a general mathematical background to digital signal processing which is vital to any modern implementations of the subject matter. Specialist sections cover acoustics, auditory perception and the features of human speech that are used in speech recognition analysis, coding and synthezis. Other sections cover music synthezis and speaker recognition.

In short this book is probably too specialized for the busy broadcast engineer – but may be of value to specialists working on the new coding systems that are becoming more generally available.

Speech and Audio Signal Processing: Processing and perception of speech and music
B. Gold and N. Morgan
Hardbound volume of 537 pages
John Wiley and Sons, UK, 1999
WWW: htpp://www.wiley.com
Ref: ISBN 0-471-35154-7. Price £22.95.

Richard Chalmers