Specifications

CD-i FAQ 2000 Edition Revised February 21, 2001
Latest version and more CD-i info: http://www.icdia.org
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second) x 384 bits = approx. 3.6 Kbyte per second. Due to this low bit rate, only very simple
graphics can be stored. CD+Graphics can show 16 colors at one time on the screen, from a palet
of 4096 colors in a resolution of 288x192 pixels. Any font that is used has to be encoded in the
graphics stream as a graphical element. CD+G allows for the change of colors used on the
screen, so that words can be highlighted for singalong purposes. CD+G is mainly used in Japan
for karaoke-applications, and never gained much popularity outside this country. However, in
Japan quite a few CDs were enhanced with CD+Graphics.
CD+G can be played on CD-Audio players with a Digital Output connected to a CD+G decoder,
on most game consoles (like CDTV and 3DO) and on dedicated CD+G players. Although
CD+Graphics is technically not related to CD-i, Philips included CD+G playback in all of its
consumer CD-i players (CD+G playback is not included in the professional players CDI 180 and
CDI 6xx series, except CDI 615). Note that also a very rare variant of CD+G exists, called
CD+Enhanced Graphics. The extended graphics cannot be shown on a CD-i player, however the
system is downwards compatible with CD+G.
A tool to create CD-Audio discs with CD+Graphics can be found on the Other CD-i tools page in
the PC/Windows download section at www.icdia.org. With this tool, you can define a
background picture for each track.
5.5 What is CD-BGM?
CD-BGM or CD-BackGround Music is a type of CD defined by Philips, Sanyo and Shinano-
Kenshi in the mid 80s. Sometimes the system is being refered to as BMS (Background Music
System). CD-BGM is used to store up to 10 hours of audio to use a background music in stores,
shopping malls, etc. CD-BGM uses ADPCM level B mono audio to accomplish this. The music
was stored in 8 tracks, all of which were devided in titles. Usually there were about 15 titles per
track, resulting in about 120 songs per disc (about 8 hours). Although dedicated professional CD-
BGM players were made available to play the discs (of which the Philips BMS 3000 was the most
well-known), every CD-BGM disc also needs to include a CD-i application to allow for playback
on a CD-i player.
It is not defined what features this application should include, as long it allows for the music to be
reproduced on a CD-i player. This is why the early CD-BGM discs from Sanyo showed a screen
devided in two halfs, with the upper half displaying 'start', and the lower half displaying 'stop'!
Actually, these discs were the first commercially released discs for CD-i ever. Fortunately, Philips
put some more attention to its CD-i application for CD-BGM. It show a list of all tracks that are
available on the disc, which can then be selected for playback. Several hundreds of CD-BGM
titles were made by Philips alone. Note: you cannot buy CD-BGM discs, they could only be
'rented' by professional users from selected Philips partners.
An article describing the history of CD-BGM and the features of Philips' CD-i application for CD-
BGM discs is available in the Related Technologies section at www.icdia.org.
5.6 What is a CD-i Bridge disc?
A CD-i Bridge disc is a CD-ROM/XA disc which includes a CD-i application for playback on a CD-i
player. A CD-i Bridge disc is based on the ISO-9660 file system to allow for the usage on other
platforms like PCs or Macintoshes. It is not obligated to store applications for other platforms, but
they may be included on the disc. Usually, audio and video are encoded using CD-i encoding
techniques like ADPCM for audio or MPEG for video.
Well-known examples of CD-i Bridge discs are Photo-CD, Karaoke-CD and Video-CD, but it is
also allowed to use the CD-i Bridge disc 'specification' to make a dedicated disc type, as long as
the disc is based on the ISO-9660 filesystem and it includes an application for playback on a CD-i
player.