> With all this said we have some choices: > > 1) Store the PWM signal > This is the most similar to how the disc is stored. It requires a lot of bandwidth, > and the emulator has to demodulate everything. > > 2) Store the FM signal > This is essentially the same as above but I don't think it can easily recreate the > original medium. It requires less bandwidth though. > > 3) Store the streams > This demodulates the audio and video but doesn't process the video signal. The > emulator has to do it. > > 4) Capture the video > This demodulates everything and also converts the video to some lossless format. You > also have to define a format for v-blank data.
Option 1 still seems like the logical choice, it's the closest we can get to a digital source, and offer the least amount of noise or distortion, disk space is cheap, it really doesn't matter if the disc image is the size of Blu-Ray rip, it's doesn't have to be the final format used by the emulator. We aren't trying to emulate the laserdisc player, just it's output (or at least at this point)
My thought is, that if we have as close to raw source copy as possible, all the demodulation and post processing can be done digitally, everything is a calculation and 100% repeatable. We can produce a near lossless and consistent image of disc contents that is also practical to use in MAME.
The other option, introduce more and more analogue noise, and by the time you get to option 4 you would be lucky if one frame matched out of a thousand captures of the same disc, every capture would different from the last, so you always missing something.
A raw option 1 rip is impractical as the final format, but offers the most control over the quality. It also makes capture to capture comparisons more practical, if your trying to eliminate variances, or to build a composite disc image from more than one copy of the same game, like if your dealing with bit rot.
I can see how the demodulated option are attractive, but they seem to come with a lot of compromises.
Again I'm no electrical engineer, this is just what I think would give the best results.