Overview

In this chapter the principles of video compression are explored, leading to descriptions of MPEG-1, MPEG-2 MPEG-4. MPEG-4 Part 10, also known as H.264 or AVC, is also covered, and for simplicity it will be referred to throughout as AVC.

MPEG-1 supports only progressively scanned images, whereas MPEG-2 and MPEG-4 support both progressive and interlaced scan. MPEG uses the term 'picture' to mean a full-screen image of any kind at one point on the time axis. This could be a field or a frame in interlaced systems but only a frame in non-interlaced systems. The terms field and frame will be used only when the distinction is important. MPEG-4 introduces object coding that can handle entities that may not fill the screen. In MPEG-4 the picture becomes a plane in which one or more video objects can be displayed, hence the term video object plane (VOP).