VGA Capture Thread

Discussion about old graphics cards, monitors and video related things.

Re: VGA Capture Thread

Postby arncht » 2019-8-21 @ 05:22

It could be i interesting to us, compared to the actual scale filters.

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Re: VGA Capture Thread

Postby appiah4 » 2019-8-21 @ 06:54

Now THAT is a nice scaling algorithm..
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Re: VGA Capture Thread

Postby elianda » 2019-8-21 @ 09:21

Actual use for capturing seems limited:

- works only on Turing
- an application must use a resolution < desktop resolution
- It must be possible to set the lower resolution

So one would need to capture a viewer application in fullscreen mode. All frame sync information is lost.

Also the current implementation does not distinguish between resolution and aspect ratio:

So one can either upscale the original resolution assuming square pixels to the same aspect ratio in the desktop resolution
or
upscale the original resolution to the desktop resolution at the aspect ratio of the desktop resolution.

So if I have as original resolution 720x400 at a 4:3 aspect I can not scale it to e.g. 1440x1080. It would scale instead to 1920x1067.
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Re: VGA Capture Thread

Postby imi » 2019-8-21 @ 23:40

does anyone know if there is a way of applying one of the many CRT shaders that are out there to an actual hardware capture?

I can find tons of information on emulators of all kinds and their respective shaders... but nothing whatsoever on applying CRT shaders to actual captured footage from real hardware after the fact.
there is a "shaderfilter" plugin for OBS, that lets you apply shaders, but the information around it is really lacking unfortunately... any tutorial is really only focusing on how to use and apply shaders, not on how to actually create them, of course none of the CRT shaders that are around "just work" in there ootb, and I can't unfortunately find any programming reference on how to actually translate any of the shaders to work in OBS, I wouldn't know where to start... I figured it needs to be in HLSL? but there is probably some critera that needs to be met for a shader to actually work in the OBS plugin.

It would be awesome if anyone knows anything about that, thanks in advance :)
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Re: VGA Capture Thread

Postby elianda » 2019-8-22 @ 09:34

If you target OBS, then you have to write an effect using the API: https://obsproject.com/docs/reference-l ... fects.html
There you can include the CRT shader.

While OBS is good for live streaming it has its drawbacks for capturing because it does not lock the capture frame rate to the source frame rate. Actually it is not intended by design as you can combine multiple sources to one output stream.

So it would probably be more useful to put the CRT shader in some post processing filter of a video editor program.
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Re: VGA Capture Thread

Postby imi » 2019-8-22 @ 12:04

elianda wrote:If you target OBS, then you have to write an effect using the API: https://obsproject.com/docs/reference-l ... fects.html
There you can include the CRT shader.


thank you for that link, going to look into that in the evening, I do actually want to use it for streaming, that's why I was asking for OBS :)

the main issue I had with all the shaders I found was that I think they were referencing specific things from the programs/emulators they were written for and I really didn't know how to translate that for use in OBS.
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Re: VGA Capture Thread

Postby leileilol » 2019-8-22 @ 12:33

The thing about CRT shaders is that they'll only look best when they know about the source resolution they're working with (like 320x200 to a CRT'd up 1280x960). Typical CRT shaders applied on something like reshade or whatever would mess it up and be super moirey (or even worse, like force a 'retro' resolution by doing a bit of imprecise pixelation)
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Re: VGA Capture Thread

Postby imi » 2019-8-22 @ 13:26

shouldn't an emulated shadow mask always be the same "size", independent of the actual input resolution?

my primary goal is to distort the image and emulate a shadow mask like in CRT-Geom
I read that shadow mask would only look good on 4k, but I watched a few videos of it on youtube in lower resolutions and it looked quite pleasing imo.
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Re: VGA Capture Thread

Postby arncht » 2019-8-22 @ 19:49

i am afraid, you can create just a “zoomed” shadow mask, because the pixel size difference is not big enough between an old 14 inch 0.28 display, and a modern 4k, but much bigger screen.

Eg 4k 27” 0.1481mm dot pitch
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Re: VGA Capture Thread

Postby Uplinkpro » 2019-9-08 @ 08:34

So is there a definitive way to capture VGA with an E1S ? Im assuming a vga>dvi connector will not suffice.
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Re: VGA Capture Thread

Postby havli » 2019-9-08 @ 12:26

E1S has DVI-I connector and supports both analog and digital input... So yes, VGA->DVI adapter will work.
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