awe444
@awe444
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In a very limited sense, yes, you can already kind of do it. You can already with the OSSC change the scanlines on a 480p input from 10101010 pattern to 11001100 which can make pre-linedoubled content useable with scanlines.
It would be nice though to do a 10001000 pattern (thin scanlines), and furthermore there is no such functionality for pre-linetripled content input as 720p (we’d need option to mask every third line in the output). The prescaling done by RT5X solves all of this by first downscaling and then allowing full use of the already existing scaling features, rather than having many small edge-case scanline options for prelinemultiped content.
January 1, 2022 at 1:10 AM in reply to: can we expect some new firmware for the “normal” OSSC ? #50948Still would love to see this scanline feature: https://videogameperfection.com/forums/topic/option-to-only-draw-every-other-scanline/
Just realized that for the desired use case with 3x prescaled content (usually a 720p signal), there’d need to be an option to draw a scanline on every third line.
Another way to regard this functionality would be a downscale followed by an upscale (different upscale/downscale factors of course), with scanlines applied to the final output. If the OSSC Pro can accomplish that “chain” of processing, it would give the same end result.
While it’s a legitimate feature request for sure, just want to make sure you’re aware of the hotkey profile-loading method: press the “10+” button on the lower left of the remote control followed by the number button corresponding to the profile you want to load. Doing it that way makes it unnecessary to use the “load profile” function in the settings menu entirely, avoiding your stated issue. That said, I’ve also ran into the opposite problem that you had: loading a profile when meant to save one, losing all the customized settings I had just tweaked. So I agree it’d be a useful safety measure. Maybe a “press 1 to confirm” when saving and a “press 2 to confirm” when loading.
Another great use case for this feature would be with the Game Boy Interface outputting its OSSC-specific 360p mode. Since that’s a pre-linedoubled image, even-only (or odd-only) scanlines would make for a nice overlay. Same idea with horiz+vertical (grid pattern), it’d look awesome if the every-other-on option were possible.
@videogameperfectionrocks: Keep up the useful work you’re doing here!
As you go through tuning the OSSC for your PCBs, please share (here in this thread or elsewhere) the OSSC-reported line counts and frame rates of the various boards, as well as the optimized sample rates you discover. The MAME drivers are often incomplete or imprecise when it comes to those parameters (e.g., many drivers just assume an exact 60Hz output). I’m sure these measurements will aid the community in many ways for years.
+1 for this feature request!
Your math is correct assuming the rendered anamorphic image is 640px wide inside the 720px active horizontal width.
However, I’ve observed that, when set to widescreen mode, the Wii actually seems to render content across the full 720 active pixels, or at least much closer to the full 720 than to 640 (some content has more blank padding than others). In contrast, when the Wii is set to 4:3 mode, it instead renders 640 pixels wide as expected (though at the same 858 total dots/line as in widescreen mode).
I invite others to confirm/refute the above stated observations, but assuming the unstretched anamorphic image (not including horizontal blanks) is indeed 720×480, the desired horizontal scaling (to end at 853.333×480 nonsquare pixels) is 32/27 = 1.185185…, whereas for 640×480 the stretch factor would be 4/3 = 1.333…
Regardless of it being a 4/3 or 32/27 scaling that’s needed to properly display the anamorphic image at 16:9, the OSSC’s means of doing the “stretching” should ideally be via horizontal integer scaling as opposed to interpolation. Basically just like how the OSSC already can “stretch” a 256×240 image to a 4:3 ratio via a 5x horizontal scaling with a 4x vertical scaling. That kind of solution for this situation with the Wii would require at a minimum doing line3x for the 480p Wii output (1440p), which isn’t an option on the OSSC hardware but maybe its successor?
An advanced scanline setting (in addition to current “Off”, “Auto”, “Manual”) with the ability to independently set intensities of mask lines 1-5 (from 0 to 100%) would fulfill the wishes I suppose. It’s not too much work so the feature could make its way to upcoming fw releases soon.
Hope this independent mask lines feature can make it into firmware 0.82. The hybrid/multiplicative scanline functionality introduced in 0.81 will be very fun to play with in the meantime!
While I don’t have an X68000 to share experience with, I do often use an XPC-4 in the chain after my OSSC, solely for the ability to framebuffer its 4x240p or 2x480p output into a pixel-perfect-scaled 1080p frame. It’s a very good combo that I feel is overlooked compared to using DVDO or other scalers for the buffering. I’d be quite interested in having (and contributing to) a section on the wiki about the OSSC/XPC-4 combo
Very useful and interesting to know, thanks for the explanation!
Reviving this one for a different reason:
I’ve got a 800×600 PC signal with a 800×480 image centered (letterboxed) inside of it. Using a V active of 480, the current V backporch upper limit of 64 prevents me from being able to properly vertically center the image. A higher upper limit of 128 or 255 would easily be adequate, is such a change possible? Thanks
August 23, 2017 at 12:56 AM in reply to: 1920 lines horizontal sampling/output for all inputs + aspect ratio controls #14685@marqs yes, I can confirm the 800 dots/line value for 480p directly from observations with the OSSC. It was an RGsB signal and I was using “VESA” sampling setting on the OSSC at the time (not the “DTV” setting). Also worth noting that I was using the GSM forced mode with “VGA” in the label (as opposed to the mode with “HDTV” in the label). Hence it is quite possible there’s a 858-dots/line mode for 480p as well.
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