HDMI Scanline Generator

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Fudoh
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HDMI Scanline Generator

Post by Fudoh »

just saw this video by ETA Prime on YT: https://www.youtube.com/watch?v=SFSRGBv9enU
Ebay: https://www.ebay.com/itm/112689378389

Just wondering if anybody here tried one of these already ? From the video it sounds and looks horrible. It says that it rescales your video (to a resolution which wouldn't match the scanlines). Sounds silly to me, since 720p or 480p would be ideal to put scanlines on top of it.

I'm also surprised to see such a device mass produced like this without any community based projects predating it.
beharius
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Re: HDMI Scanline Generator

Post by beharius »

AFAIK, it first converts to VGA then adds scanlines and finally converts back to HDMI. So it's a 1:1 converter, not a scaler.
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bobrocks95
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Re: HDMI Scanline Generator

Post by bobrocks95 »

Oof those are really uneven scanlines.

The fact that they think you'd need a tint/color adjustment for a digital signal is a big red flag right from the start.
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Xyga
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Re: HDMI Scanline Generator

Post by Xyga »

Sucky design award (and sucky reviewer too, wth)
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Unseen
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Re: HDMI Scanline Generator

Post by Unseen »

Fudoh wrote:I'm also surprised to see such a device mass produced like this without any community based projects predating it.
Maybe there is noone in the community that would want their name associated with a device that takes the analog route to add scanlines to a digital signal?

If it weren't for that pesky 1080p resolution, a fully digital scanliner could probably be made with a Spartan 6 FPGA by reusing the HDMI rx/tx code from the NeTV. The original can do graphical overlays on top of an HDMI signal, but a pure scanline generator is much simpler.
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Fudoh
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Re: HDMI Scanline Generator

Post by Fudoh »

from the NeTV.
haha, yes. I have a NeTV here to try it exactly for that reason. Just didn't get around to look into the programming yet.
RGB0b
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Re: HDMI Scanline Generator

Post by RGB0b »

Wow, that looks pretty terrible. I wish there was a 4K scanline generator, as it should be enough resolution to mimic vertical scanlines as well. Probably not a 1000 TVL BVM, but maybe a 600-line? Horizontal scanlines can be great, but to get a more accurate look of a CRT, you'll need vertical scanlines too.
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Xer Xian
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Re: HDMI Scanline Generator

Post by Xer Xian »

retrorgb wrote:Horizontal scanlines can be great, but to get a more accurate look of a CRT, you'll need vertical scanlines too.
If one wants to emulate the look of high TVL monitors and go beyond a scanline overlay, adding a mask effect is not the 1st item in the list imho.

What simulated scanlines on fixed pixels displays really miss vs the real thing is the lack of phosphors blooming, or glow, or whatever it actually is. On a high TVL CRT, bright phosphors appear to bleed into the blank scanlines.

Camera shot of an 800 TVL CRT: http://image.ibb.co/jkcSRm/RGB_Native.jpg
Frame capture of OSSC's Line5x (chained to additional scaler, AR is a bit off): http://image.ibb.co/dVZP6m/1200p_SL.jpg
(click to enlarge)

Crops:

Image Image
Image Image

It's subtle, but it does make the result a bit less sterile imho. I don't think this can be easily implemented on fixed pixels displays though..

(the processed image is also lacking in contrast and color accuracy, but that must be down to my equipment)
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Xyga
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Re: HDMI Scanline Generator

Post by Xyga »

Ouch something's wrong with the OSSC capture here, there's been some rescaling applied somewhere.

Regarding the 'almond shape' and bleeding it is possible to imitate outside of emulation and shaders using the EE/DE of a VP50 Pro for instance, and playing on the blank line's intensity on the OSSC, but that's only static-cosmetic since brightness and contrast are fixed indeed, and well, the first issue to attend is motion anyway.
Scanlines simulation will never look really great as long as it's a static, lifeless thing plastered over a too-slow sample-and-hold panel.
I've almost completely lost interest in fake scanlines now, only selecting the most appropriate scaling/factors and smoothing per-game.
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Xer Xian
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Re: HDMI Scanline Generator

Post by Xer Xian »

Xyga wrote:Ouch something's wrong with the OSSC capture here, there's been some rescaling applied somewhere.
Yes, it's 1600x1200 rescaled to 1920x1080 with a bit of underscan due to limited AR controls. Other upscalers can probably get a cleaner/sharper image, but that's beyond the point.

By 'almond shape', are you referring to the rounded/smoothed edges of the scanlines? Yes, that's another relevant difference I forgot to mention. The outline of the ship (and the background next to it) are all blocky on the processed image, but nicely rounded out on the CRT.

Of course, these are clearly all subtleties that are difficult to notice while gaming, but they do help me rationalize buying CRTs in 2018 :)
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Xyga
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Re: HDMI Scanline Generator

Post by Xyga »

Xer Xian wrote:By 'almond shape', are you referring to the rounded/smoothed edges of the scanlines? Yes, that's another relevant difference I forgot to mention. The outline of the ship (and the background next to it) are all blocky on the processed image, but nicely rounded out on the CRT.
Well I'd rather call the OSSC's output unprocessed which is why it looks blocky, CRTs naturally smooth out everything thanks to the dots shaping with brightness intensity, but it's much less pronounced on high-TVL sets of course (check the vertical part of the hull's yellow outline, on a lower-TVL one they'd appear to be touching even on photo)
To get closer to that on the OSSC in x5 we'd need to add a hint of smoothing, just a tiny bit, but it'd be considerably better without having to use either a secondary processor or the monitor's own sharpness settings. I doubt the OSSC on its own can combine a 'filter' and scanlines though, or maybe with a dedicated firmware, dunno.

Back to the scanline generator in any case yeah if it can't even do what the basic SLG design does adding HDMI to the board won't make it better, agreed also one dedicated to 4K output bypassing any scaling and processing would be a much more useful thing for the future, but that's practically asking for a 4K OSSC. ^^
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DAVI22
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Re: HDMI Scanline Generator

Post by DAVI22 »

hi, is there any project to create a slg3000 on hdmi in the future?
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evil_ash_xero
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Re: HDMI Scanline Generator

Post by evil_ash_xero »

Has anything good come out since then? I have a Retrotink 2x Multi, and I like it pretty well. However, the scanlines just make everything too dark (too bad the 2x doesn't have a 50 percent scanline option). I'd like some kind of in between.
headlesshobbs
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Re: HDMI Scanline Generator

Post by headlesshobbs »

I don't think there's been anything too good for hdmi sourced material beyond what the ossc provides.

Not too shocking, but it's obviously where our newer content is going and we need good resources for it.
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evil_ash_xero
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Re: HDMI Scanline Generator

Post by evil_ash_xero »

headlesshobbs wrote:I don't think there's been anything too good for hdmi sourced material beyond what the ossc provides.

Not too shocking, but it's obviously where our newer content is going and we need good resources for it.
Hopefully some more devices will pop up in the next few years.
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mitsuruga
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Re: HDMI Scanline Generator

Post by mitsuruga »

Is there any good and lag free option by now? I am looking for a solution to use it with xbox 360 (HDMI) and Cave games. Any recommandations?

https://www.amazon.com/dp/B07JYW96Q2/?c ... _lig_dp_it -> This one seems to be a cheap option, but not sure if it is lag free.
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