VCD

     Video CD or VCD, or Compact Disc digital video, is a standard digital format for storing video on a Compact Disc. View CDs, as VCDs are sometimes referred to, are playable in dedicated players, personal computers, and many DVD players.

     The VCD standard was created in 1993 by Sony, Philips, Matsushita, and JVC and is referred to as the White Book standard.

Technical specifications

     VCD display resolution is 352x240 pixels (NTSC) or 352x288 pixels (PAL), approximately one quarter of full TV resolution (720x480 for NTSC, 720x576 for PAL). VCD video is in MPEG-1 format; audio is encoded as MPEG Layer 2 (MP2); video is stored at 1150 kilobits per second, audio at 224 kbit/s. Overall picture quality is intended to be comparable to VHS video, though visual artifacts may be noticeable in some cases. Poorly compressed video in VCD tends to be blockier than VHS video.

     Since the overall bit rate of VCD is approximately equal to the bit rate of an ordinary audio CD, the length of video that can be stored is similar to that of a CD: a standard 74 minute CD can hold about 74 minutes of VCD-format video.

SVCD

     Super Video CD (Super Video Compact Disc or SVCD) is a format used for storing video on standard compact discs. SVCD falls between Video CD and DVD in terms of technical capability and picture quality.

     The VCD standard was created in 1993 by Sony, Philips, Matsushita, and JVC and is referred to as the White Book standard.

Technical specifications

     SVCD has two-thirds the resolution of DVD, and more than twice the resolution of VCD. Video is stored at 480x480 pixels for NTSC, and 480x576 pixels for PAL and SECAM. One CD-R disc can hold 35 to 60 minutes of SVCD-format video, at a picture quality roughly comparable to Laserdisc.

     Video is encoded as MPEG-2, and may have a variable bit rate up to 2.6 megabits per second. Audio is stored in MP2 format, with a bit rate varying from 128 to 384 kilobits per second.

     The SVCD standard supports several other features, including hyperlinks, karaoke lyric highlighting, overlay subtitles, and DVD-quality slide shows with resolution up to 704x480 (NTSC) or 704x576 (PAL). SVCDs may have two separate stereo audio tracks (for commentary or additional languages); audio may have up to 8 channels (in a 7.1 arrangement) using the MPEG Multichannel surround sound format (though space constraints and poor hardware support make it somewhat impractical).