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VCD (also called video CD, video compact disc or "disc") is a compact disk format based on CD-ROM XA that is specifically designed to hold MPEG-1 video data and to include interactive capabilities. VCD has a resolution similar to that of VHS, which is far short of the resolution of DVD. Each VCD disk holds 72-74 minutes of video and has a data transfer rate of 1.44 Mbps. VCDs can be played on a VCD player connected to a television set (in the same way that video cassettes can on a VCR) or computer, on a CD-i player, on some CD-ROM drives, and some DVD players.
VCD was introduced in 1993 by JVC, Philips, SONY and Matsushita and is described in detail in the White Book specifications. Video data is demanding in terms of storage capacity; it requires approximately 5 MB of storage per second of video, which would translate to about two minutes of video on a 680 MB CD. In order to store video information on a CD in a practical fashion, the data must be compressed for storage and then decompressed for replay in real time. MPEG-1 compresses data at ratios of up to 200:1. MPEG is an international standard, and can be used by any manufacturer to create hardware for use with MPEG video. MPEG video can also be recorded on any CD. VCD formatting removes unnecessary information from MPEG-1 data, and adds specialized video authoring capabilities through inclusion of a CD-i (CD- Interactive) runtime application.
VCD variations include: VCD 2.0, which was introduced in 1995 and adds hi-resolution stills, fast-forward, and rewind functions to the original specifications; VCD-ROM, which was introduced in 1997 and enables the creation of hybrid VCD/CD-ROM disck; VCD-Internet, which was introduced in 1997 and is a standardized means of linking video and Internet data; and SuperVCD, which uses either high bit rate MPEG-1 or variable bit rate MPEG-2 for the use of CD-R drives instead of DVD drives.
VCD is more common in Asia than it is in North America, where the VCR had already cornered the home video market by the time that VCD was introduced. Because of the ease with which VCDs can be pirated, they are creating the same kind of problem for the movie industry that MP3 caused for the music industry. Thieves may record movies from a movie screen with a camcorder, or may copy them from laserdiscs or DVDs. With the advent of recordable CDs (such as the CD-R and CD-RW), it became possible for the home user to create VCDs on some CD recorders.
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Last updated on: Jul 27, 2001
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