The Philips CD-i system is compatible with several CD standards besides CD-i: It also supports Photo CD, Video CD (VCD), BGM (Background Music) CD, Audio CD, and a couple of hybrid formats. How does CD-i Emulator handle these other formats? Would it in principle need several different emulators, one dedicated to each format? "I presume because Photo CD / VCD / CD-i use a lot of the same technology
that building an emulator with all three would be efficient compared to
three separate emulators even if more complicated", according to CD-i member Seventy7.
It would be nice to have an emulator that can emulate CD-i / VCD / Photo CD in different modes. "So for example if you're in VCD mode you don't see any CD-i menus and additional features. helps figure out which features belong to which spec of the disc." according to Seventy7. "Does a PhotoCD player display it differently than a CD-i player or does one of them offer differrent/additional features. Dedicated PhotoCD players do not run CD-RTOS." Retrostuff adds.
The current CD-i Emulator 0.53 beta 5 actually supports Photo CD's as well as VCD's, although we need to test more to build a compatibility list. The author, cdifan, adds: "To allow an emulator to behave like it's just a PhotoCD player (e.g. hide the CD-i player shell and perhaps emulator menu choices that relate to CD-i)? That does not sound very hard... Under water it would still be emulating CD-i, of course, unless you want it to be an actual PhotoCD player, which requires doing everything that the PhotoCD for CD-i application normally does... the PhotoCD spec is not that simple..."
If you want it to "really" do PhotoCD / VideoCD, not just the CD-i application thereof, then it would be different emulators. The current compatibility of PhotoCD and VCD on CD-i Emulator 0.6 is probably not terrific, "I don't think CD-XA (which is what both are) is correctly recognized. Should not be hard to fix, though; multi-session PhotoCD might be a problem. There is not much in common except the basic disc format (all CD-BRIDGE, e.g. XA based). Some CD-i technology might help for Video CD or BGM, but not for Photo CD... the quality on those discs is much better than what CD-i could render." according to cdifan.
[Thanks to the CD-i Community]