Introduction to VCD (VideoCD)
What is VCD?
Video CD is a specification for storing audio and video information on a normal compact disc. Up to 74 minutes can fit onto a standard disc or 80 minutes (or even slightly more using "over burning") on a high capacity disc.
Audio and video information is compressed using the MPEG-1 standard, giving video quality similar to that of VHS video and CD quality audio.
VCDs can be played on many standard DVD players. They can be created using PCs with a CD-R or CD-RW drive and suitable software, making them a versatile and convenient format for home use. You can transfer VHS video recordings onto VCD using a suitable capture card. Home movies shot using your DV camcorder can be edited and easily put onto VCD. Any video you have on your PC can also be transferred to VCD.
The original version 1.1 specification dates from 1993, with the 2.0 specification published a few years later adding features for displaying still picture and allowing more user interaction and PAL (25Hz) video. All modern VCD authoring software and DVD players should support the 2.0 standard.
XVCD is an extension of the VCD standard. It is not a standard in itself, and means a VCD that does not conform to the VCD specification, but is still playable on many VCD, SVCD and DVD players. This is possible since the hardware in many players is designed to play other formats as well. To do this it must support other display resolutions and higher bitrates. XVCDs take advantage of the fact that players are designed to be "fault tolerant", that is play discs that do not strictly adhere to the standard in the best way that they can.
The most common use of XVCD is to increase the bitrate of the video stream. Total bitrates (video + audio) can be doubled and still be playable on many SVCD players (SVCD bitrates can be up to double that of VCD, so players must support these bitrates in their MPEG decoder). Typically an SVCD player will play XVCDs with bitrates video bitrates up to 2500 kbps.
Technical Specifications of VideoCD 2.0