Nvidia DSR, any use for emulators ?

[akumajo]

Hi there,

DSR : http://www.geforce.com/hardware/technol ... technology

Was testing this on Dark Souls 2 (4K) on my projector (1080p) and I like it.

Does anyone tested this already on MAME or any other emulator, it should works as long as it use DirectX/OpenGL ?

Maybe it's a bad idea, who knows .

Thanks.

[Ed Oscuro]

I don't think this would be any better than traditional scaling methods for 2D content. Its main advantage is in reducing aliasing and improving other details.

[Lord of Pirates]

The only use I've found for DSR so far is taking higher resolution screenshots.

[Fudoh]

I would certainly like to see some HLSL comparisons. 1080p often times isn't enough for nice raster image effects, so I could image that rendering internally at something like 1600p would help to improve the end results. On the other hand I don't know how good NVIDIA's downscaling really is - but it shouldn't be too hard to do a quick comparison.

[Xyga]

I could be wrong but it seems to me the algorithm is tuned to apply to 3D polygonal stuff already rendered in high-res then (video)downscaled.
I'm having a hard time picturing this working wonders on a single flat scanlined image... the engine better be close to miraculous.

[Ed Oscuro]

I think it's just using a traditional fast downsampling algorithm on the large initial 2D render.

If the only option for scaling we had was nearest neighbor, this might be something, but there are other options out there. Basically it seems to me that the entire first step is unnecessary, and the second step (downscaling) would just give similar results to scaling up.

But we'll see...with downscaling you don't get as many opportunities for interpolation-derived artifacts, so maybe it's not so bad.

Also it seems safe to say that with any Maxwell card (even the 750 ti, if that supports this), fill rate for old arcade games will not be a problem, nor will rendering that content be a big drain on the card. Even the lower end cards should have the pixel fillrate to support high resolutions at framerates far above 60Hz, so basically any arcade game you can think of will be easily supported.

[akumajo]

DSR was enabled for older GTX (5xx/6xx/7xx) with recent drivers.

Some faq I found online : http://forums.guru3d.com/showthread.php?p=4939341

I will try this week end.

[ZellSF]

It would obviously only be useful for 3D emulators that don't already support downsampling by themselves (I'm pretty sure Dolphin/PPSSPP/PCSX2 already do) and support arbitary 3D rendering resolutions (probably ruling out MAME, pSX, SSF, XEBRA).

I don't see it having many uses.

For 2D, upscaling a 240p image to 4K then downscaling it to 1080p (just an example) makes no logical sense. No matter what scaling method, you never upscale an image just to downscale it again. It doesn't give advanced shaders more room to work with since the end target resolution is still the same.

[Ed Oscuro]

For 2D, upscaling a 240p image to 4K then downscaling it to 1080p (just an example) makes no logical sense.

I agree (just with this short statement) except for uncritical use of the term 240p. For many emulators the output resolution isn't limited to 240p, and besides, what is 240p? It should be 4:3 but the actual number of horizontal pixel transitions might lead emulator authors to create any number of horizontal resolutions. So right away we should realize that a good modern emulator design does not tie the output resolution to some "correct" output resolution and only integer multiples for scaling, because on square pixel displays this often results in incorrect aspect ratios and in any case the sharp pixel transitions are essentially fantastic (though you could certainly approach the look with a high-end CRT).

"Upscaling only to downscale" is against the spirit of DSR, which is about downsampling from higher resolution source files. So yeah, any emulator which only outputs to something in the vicinity of 320x240, 640x480, etc. is clearly inadequate. However, MAME allows output at whatever your screen resolution is, which is much more useful most of the time.

Generally speaking, the limited resolution of 240p sources means that I don't see that it would be especially useful compared to good scaling algorithms. However sampling theory says that working from larger source is reasonable, but there's nothing that says you are guaranteed to get good details out of upscaling, which is what any non-downscaling method (short of the original raster display method) has to do. Interpolation is almost the reverse of sampling in this case. There's nothing that says that DSR-like methods are tied to rendered 3D content only - the files it works on are entirely 2D and these methods have been known for a very long time in entirely 2D contexts.