CD+G (also known as CD-G, CD+Graphics and TV-Graphics) 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 utilize 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 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 (4-bit) graphics are displayed on a raster field which is 300×216 pixels in size.
- Dedicated Karaoke machines
- NEC TurboGrafx-CD (a CD-ROM peripheral for the TurboGrafx-16/PC Engine) and TurboDuo
- Philips CD-i
- Sega Saturn
- Sega Mega-CD
- JVC X'eye/Wondermega (a combined Mega Drive and Mega-CD sold by Victor (known as JVC outside Japan))
- 3DO Interactive Multiplayer
- Amiga CD32
- Commodore CDTV
- Atari Jaguar CD (an attachment for the Atari Jaguar).
- Some CD-ROM drives can also read this data. Since 2003, some standalone DVD players have supported the CD+G format.
Compact Disc + Extended Graphics (CD+EG, also known as CD+XG and Extended TV-Graphics) is an improved variant of the Compact Disc + Graphics (CD+G) format. Like CD+G, CD+EG utilizes basic audio CD features to display text and video information in addition to the music being played (288x192 pixels, 256 colors). This extra data is stored in the subcode channels R-W. Very few, if any, CD+EG discs have been published.
MP3+G is a karaoke file format that was created to allow CD+G karaoke to be played from a personal computer easily and quickly. MP3+G was created from the combination of the MP3 audio file (the CD audio is converted and compressed to MP3) and a raw CDG file which contains the RW subchannels from the CD+G track. It was first called MM+G in combination of various audio formats synchronized to a CDG file. MP3 and WMA became the most popular audio format used for karaoke and therefore MP3+G and WMA+G became the most popular formats used. Microsoft first unofficially adopted the WMA+G for use on the Xbox for the Xbox karaoke product.