e are several different versions of MPEG compression. They are described in the following sections. MPEG-1 MPEG-1 was created to solve the transmission and storage challenges associated with relatively low-bandwidth situations, such as PC to CD- ROM or low bit rate data circuits. MPEG-2, on the other hand, was designed to address much more sophisticated transmission schemes in the 6 to 40 megabit per second range. This positions it to handle such applications as broadcast television and HDTV, as well as variable bit rate video delivered over packet, Ethernet, and Token Ring networks. MPEG-2 The original MPEG-1 standard was optimized for CD-ROM applications at 1.5 Mbps. Video, one of the applications that users wanted to place on CD, was strictly noninterlaced format (progressive scan). Unfortunately, today's television pattern is interlaced. This created a problem; luckily MPEG-2 handles the conversion well. MPEG-2 initially gained the attention of both the telephone and the cable television industries as the near-term facilitator of video-on- demand services. Today, it is widely used in DVD production because it has the ability to achieve high compression levels without loss of quality, as well as in cable television, DBS, and HDTV. MPEG-2 has also found a home in corporate videos and training products because of its ability to achieve CD-compatible compression levels. MPEG-3 MPEG-3, also known as MP3, has become both famous and infamous of late and has made Napster and Metallica household names. MPEG layer 3 is a type of audio CODEC that delivers significant compression of as much as 12:1 of an audio signal with very little degradation of sound Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. Protocols Protocols quality. Higher compression levels can be achieved, but sound quality suffers. The standard bit rates used in MP3 CODECs are 128 a