Chapter 8 - Video and audio decoding

Abstract

This chapter discusses the basic elements of the video/audio decoding part of a DVD player. The waveforms shown are a color bar display. Multiplexed PES packets from the radio frequencyprocessor are processed by the V/A decoder to reproduce the original digitized luminance Y and the two chrominance color difference components CR and CB. They are multiplexed on an 8 bit bus and fed into a digital PAL/NTSC encoder to produce analogue video signals, which may be used to picture reproduction on a television receiver. Three sets of video signals are produced by the PAL/NTSC encoder: Luminance Y and chrominance C, composite video, and R, G, and B. The first set is for the S-video output port, which provides the best quality video, and RGB and composite video second and third best, respectively. Audio packetized elementary streams (PES) are fed into their appropriate PES decoder: MPEG, AC-3, or linear PCM. DVD players support three audio encoding techniques, MPEG-2, Dolby Digital (AC-3), and Linear PCM, providing mono, stereo, and multichannel audio outputs. Downmixing involves matrixing the center and surround channels onto the main stereo channels.