> > > OK, let me pose this question in relation to the above: does this mean that MAME > > > should also emulate the laserdisc players in their entirety for the games that > used > > > them? Digitised disc data could be fed to a virtual laser pickup, the VBI decoded > > > within the LD player virtual machine, and the appropriate frame data fed from the > > > virtual player's video output to MAME's framebuffer for display. > > > > Yes it should. And it should output the composite video so we can decode it in a > > programmable shader and provide a set of dynamic picture controls like you'd get > with > > a real system. > > > > > Granted, I am being slightly silly in asking that question, but not entirely. > Given > > > that we're talking about reproduction of an analogue medium in a digital format, > > > we're always going to be stuck with the 'how far do we go' and 'where do we stop' > > > questions. > > > > And people said storing home computer tape software as WAV files and emulating the > > front-end was silly (rather than just storing bytes), or emulating keyboard MCUs > and > > interface chips was silly (rather than just faking it at protocol level), and > > emulating CPS2 encryption was silly (rather than just using XOR files), or > requiring > > encrypted NeoGeo GFX ROM images was silly (rather than using pre-decrypted GFX like > > NeoRageX), yet here we are. > > Permit me another question? > > This seems to me to be crossing from emulation to simulation? > > The laserdisc is an analogue to a hard drive, so it feels to me like extending this > means that MAME should simulate the cylinders and head(s) of a hard drive, the IRQ's > generated, the ISA/PCI bus, memory controller, etc. The laserdisc player isn't really > that different from the hard drive as it is just the medium that reads out the bytes > stored on a "Storage platter". > > I feel like laserdiscs are being held to a higher standard than hard drives with > respect to being supported in MAME. Shouldn't the support requirements be the same > for both mediums? > > I completely get why we want to have the laserdisc itself converted into a series of > bits to represent the physical layout of data on the disc, I'm just wondering why the > laserdisc player itself isn't emulated? > > That requirement for the laserdisc player to be simulated seems to me to be the thing > preventing laserdisc inclusion in MAME as it seems to me to be setting an impossibly > high requirement. Though of course, since I've never been involved in MAMEDev > discussions I could be unaware of other requirements preventing it.
It is a higher standard because it is analogue. We need the best SQNRs that are practical. Even with good design every rip will be quite different and have a different fingerprint. This is because the data is left as is and is not quantized to discrete values. It contains the random variation caused by noise.