Philips CD-i 1984 and it was first publicly announced in 1986. The first Philips CD-i player, released in 1991 and initially priced around US$1,000, was capable of playing interactive CD-i discs, Audio CDs, CD+G (CD+Graphics), Karaoke CDs, Photo CDs and Video CDs (VCDs), though the latter required an optional "Digital Video Card" to provide MPEG-1 decoding. Philips also licensed the CD-i format to other manufacturers for use, and there were also CD-i players by Sony under the "Intelligent Discman" brand. Philips marketed the CD-i as a "home entertainment system" in Europe, but more as a games and educational machine in the U.S.
Video CD audio frequency range is limited to those sounds most clearly heard by the human ear. The VCD standard also features the option of DVD-quality still images/slide shows with audio, at resolutions of 704×480 (NTSC) or 704×576 (PAL/SECAM). Version 2.0 also adds the playback control (PBC), featuring a simple menu like DVD-Video. Shortly before the advent of White Book VCD, Philips started releasing movies in the Green Book CD-i format, calling the subformat CD-i Digital Video (CD-i DV). While these used a similar format (MPEG-1), due to minor differences between the standards these discs are not compatible with VCD players. Philips'