CD+G


CD+G is an extension of the compact disc standard that can present low-resolution graphics alongside the audio data on the disc when played on a compatible device. CD+G discs are often used for karaoke machines, which use this functionality to present on-screen lyrics for the song contained on the disc. The CD+G specifications were published by Philips and Sony in an updated revision of the Red Book specifications.
The first CD to be released with CD+G graphics was Eat or Be Eaten by Firesign Theatre in 1985. The CD+EG is a similar format that allows for better graphics, but has very rarely been implemented in releases.

Players

Along with dedicated karaoke machines, other consumer devices that play CD+G format CDs include the NEC TurboGrafx-CD and Turbo Duo, the Philips CD-i, the Sega CD, Sega Saturn, the JVC X'Eye, the 3DO Interactive Multiplayer, the Amiga CD32 and Commodore CDTV, and the Atari Jaguar CD. Some CD-ROM drives can also read this data. Pioneer's LaserActive player can also play CD+G discs, as long as either the PAC-S1/S-10 or PAC-N1/N10 game modules are installed.
Since 2003, some standalone DVD players have supported the CD+G format. Regular audio CD players will output only the audio tracks as if it was a normal music CD, unless otherwise designed to read the extra data.

Implementation

The CD+G format takes advantage of the subcode channels R through W, which are unused in standard audio CD formats. These six bits store graphics information.
In the CD+G system, 16-color graphics are displayed on a raster field which is 300×216 pixels in size, of which only the central 288×192 area is used with a flat-coloured border drawn around it.

Compact Disc + Extended Graphics

Compact Disc + Extended Graphics is an improved variant of the Compact Disc + Graphics format. Like CD+G, CD+EG utilizes basic audio CD features to display text and video information in addition to the music being played. This extra data is stored in the subcode channels R-W. Very few, if any, CD+EG discs have been published.

Specifications