Much the same question as in that Apple II thread. There are many Commodore 64 emulators around but few seem to concern themselves with highly accurate video, or do much beyond a 1:1 pixel mapping using the 16 "hard" colors.
I recently came across Micro64, which kinda breaks the mold - it's basically a demoscene product in itself, and as such a huge amount of effort was put into video: it combines pixel-clock-exact VIC-II emulation with fully featured PAL decoding, and the resulting image reproduction is more faithful than any other C64 emulator I've seen (so far).
The configurable features range from impressive (a curved CRT surface with visible retrace flicker, shadow mask and so on) to silly (simulated daylight reflection from an open window). But all the bells and whistles can just be turned off, which gives a clean, quality image that looks about as accurate as it gets.
To me, it's definitely something we could use for screenshots here at MG... here's an example (with the borders cropped away). Any thoughts? Would this type of screenshot be accepted?
(Edited by joyvalley (131430), Dec 26, 2012)Re: C64 emulator screenshots
joyvalley (131430), Dec 26, 2012
The ones i did, i always made with VICE or CCS64, and when you do them without all the options for quality improvement, you should get no trouble with approvers, with or without borders, as long as they come as close as possible to the original hardware and with the native 320x200 resolution (those users wanting higher resolution can setup their preferences: Automatically enlarge smaller screenshots (320x200, etc.)), not the double-sized example you used here, they should be fine, C64 is normally never a problem when it comes to contributing shots here to Moby.
I realize that native resolutions are normally preferred, that's another reason why I'm asking here first. I didn't double the size of this screenshot - the emulator generated it this way, and for good reason, because this allows for more precision. It doesn't just take the underlying pixels and doubles them - it uses the extra horizontal resolution to more accurately reproduce an analog video signal.
The output of composite or Y/C video signals doesn't really conform to the sharp horizontal pixel boundaries of digital RGB... so a 1:1 pixel image (using native resolution) cannot really capture it accurately; there are sub-pixel transitions that get lost in the process. Rendering at double the horizontal resolution (640 pixels in this case) can compensate for that, and vertical resolution is then doubled for the sake of aspect ratio.
1:1 images may look adequate in many cases, but aren't really optimal - thankfully emulation has improved, and more recent emulators get better results for systems like the C64, Apple II or composite CGA (always by rendering at double the horizontal resolution). So we might as well take advantage of that. Any fancy "special effects" for eye-candy should always be disabled, of course.
I just tried the emulator. (First impression - totally not user friendly.). Was bilinear interpolation activated in the image example and perhaps even scanlines turned off?
Looking at the example, my initial impression was that there are differences, but they seem subtile to compared to what my browser does with Moby native images when I'm not logged in. Like a fancier blur , still without much of the CRT-look I'm used to, not comparable to the effect of NTSC AppleWin. I'm writing this as someone who hasn't looked directly at actual C64 output for over a decade, but still..
I definitely set interpolation to "none" - turned off the scanlines as well, since that stuff doesn't belong in MG screenshots. I used the "full GPU" PAL emulation mode, by the way. You can enable the whole range CRT-like special effects under "PAL full emulation options" (radial distortion, noise, shadow mask etc.), but for Moby-purposes I disabled all of those as well.
The most obvious effect of NTSC AppleWin is the color-fringing artifacts - those are inherent to NTSC, but the very nature of PAL works to cancel them out, so they shouldn't be expected in this case. A byproduct of PAL is how saturation is slightly different between alternating scanlines, and how the color information of each scanline "bleeds" somewhat into the next one down - this can be seen in the above image (though I guess you'd have to look pretty closely).
But there's no interpolation on the image; all of that just accurate emulation of VIC-II PAL output. It's possible that I somehow introduced a kind of "blur" elsewhere in that gigantic heap of settings... will see later if I can eliminate that.
No. That looks awful. I know a real C64 screen can look awful, but it's a filter I can emulate in my brain even when presented with a clear screenshot. We basically want the pixels, not the noise, in emulated screens. Otherwise, we'd just use a videograbber.
The Apple II is a different case, since so many games make use of the problems in the video system. That's not the case with the C64.
there's also the factor in that the NTSC C64 appeared more bright and colorful, and that emulator (like all commodore emulators) neglect to cover the NTSC CRT emulation. Maintaining screenshot consistency between PAL and NTSC would be a bitch.