X 1080i, respectively. number is then normalized to a 1:1 display aspect ratio However, HDTV displays are technically defined as (dividing the number by 3/4 for a 4:3 display, or by 9/16 being capable of displaying a minimum of 720p or 1080i active scan lines. They also must be capable of displaying 16:9 content using a minimum of 540 progressive (540p) HORIZONTAL HORIZONTAL or 810 interlaced (810i) active scan lines. This enables VERTICAL SCANNING SCANNING SCANNING FIELD 1 FIELD 2 the manufacturing of CRT-based HDTVs with a 4:3 aspect ratio and LCD/plasma 16:9 aspect ratio displays with resolutions of 1024 X 1024p, 1280 X 768p, 1024 768p, and SO on, lowering costs. Audio and video compression The recent advances in consumer electronics, such as Figure 7.1-3 Interlaced displays "paint" first one-half of the digital television, DVD players and recorders, digital image (odd lines), then the other half (even lines). video recorders, and SO on, were made possible due to CHAPTER 7.1 Introduction to video CLOSED CAPTIONING, TELETEXT, WIDESCREEN VBI DATA SCALING BRIGHTNESS VIDEO NTSC / PAL, S-VIDEO CONTRAST GRAPHICS NTSC / PAL DECOMPRESS RGB/YPBPR OVERLAY VIDEO ENCODE DESCRAMBLE (MPEG 2) SATURATION SHARPNESS PROGRAM ELECTRONICS STREAM STEREO AUDIO AUDIO L DEMUX AUDIO AUDIO R DECOMPRESS (DOLBY DIGITAL AND DTS) DIGITAL AUDIO 5.1 DIGITAL AUDIO INTERFACE INPUT Figure 7.1-4 Simplified block diagram of a basic DVD player. audio and video compression based largely on MPEG-2 DVD players video with Dolby R Digital, DTS , MPEG-1, or MPEG-2 audio. Figure 7.1-4 is a simplified block diagram for a basic New audio and video codecs, such as MPEG-4 DVD player, showing the common blocks. Today, all of HE-AAC, MPEG-4.10 (H.264), and SMPTE 421M this is on a single low-cost chip. (VC-1), offer better compression than previous codecs In addition to playing DVDs (which are based on for the same quality. These advances are enabling new MPEG-2 video compression), DVD players are now ways of distributing content (both to consumers and expected 