Capture Card as a display input for a GSYNC monitor

[OUTferJUSTICE]

Hi guys! First time poster, long time lurker. I have recently moved into a tiny apartment and had to offload my PVM. The problem I'm having is that the only display device I have is a GSYNC computer monitor with only a single Display Port input. I still would like to play all my classic game systems, but the only options I have are to either use emulation, or try to play through the preview mode of a capture card.

My question is, is using a capture card a viable way to play classic games? Would the picture quality be acceptable, and would the input delay be acceptable? If so, what capture card would be the best route to go? I have RGB SCART cables for most of my classic systems and would love to continue using real hardware with the best PQ possible.

[Fudoh]

This isn't as easy as it sounds.

The theory on this fine and lag isn't a problem on native PCIe cards. The problem is compatibility though, especially when you're coming from classic systems that don't exactly output NTSC refresh rates. Also only a few models will allow you to accept 1080p60 at full specs. The Decklink Mini Recorder for example will only work with 720p and 1080i and the card is quite picky when it comes to refresh rates. For your older systems you would need an upscaler of course.

Fully equipped cards that also accept native 240p include Micomsoft's XCAPTURE-1 or the internal 512N1 card. Again, lag is no problem, but here the "live upscaling" quality isn't worth talking about.

A combo of a 512N1 along with a Framemeister could turn out quite nice though (but certainly pricey).

[Ed Oscuro]

G-SYNC monitors do have a scaler built-in - for VESA signals - but 240p support might not be a part of that. Given the DisplayPort-only nature, legacy support might be stripped. Aside from this, you need DisplayPort output on the capture card (or at least a converter).

Until somebody builds G-SYNC aware scaler, you're probably stuck with regular timings (and even then, basic resolution support - let alone anything fancier - might not come). Any system with unusual timings might not work well. I've had good success running a 55Hz game on my 60Hz-only monitor via VGA (31KHz RGBHV via XRGB2) but the "smart" Display Port implementation might foil that, and in any case my monitor offers more scaling options than usual.

nVidia's G-SYNC FAQ does mention something:

Q: Does G-SYNC work with FCAT?

A: FCAT requires a video capture card to catch the output graphics stream going to a monitor. Since G-SYNC is DP only and G-SYNC manipulates DP in new ways, it is very unlikely that existing capture cards will work. Fortunately, FRAPS is now an accurate reflection of the performance of a G-SYNC enabled system, and FRAPS output can be directly read by FCAT for comparative processing.

This might be misleading in certain ways, but the thing of interest is the possibility of incompatibility. The FAQ isn't too terribly old, but it seems the issue is unavailability of DisplayPort capture cards first, and secondly the differences between G-SYNC and the DisplayPort standards.

[Fudoh]

Aside from this, you need DisplayPort output on the capture card (or at least a converter).

the video is provided by the PC the capture card or box is running on. That's the point.

[Ed Oscuro]

Scary oversight, sorry.

We don't know the monitor (always give exact details, please!) but the Framemeister won't fully upscale the image for final viewing unless it's just a 1080p panel - this might lead to very ugly effects. It's also unclear to me whether live preview would retain the apparent requirement that the source be true fullscreen (multiple sources: ]#1, #2). At least some capture preview programs won't do this, and it looks like G-SYNC on the desktop is still being locked down (the intended behavior seems to be that it default to G-SYNC off on the desktop). Finally, that seems like a hell of a long input latency chain: console to (optional?) Framemeister, capture card, PC data system to PC graphics rendering system and from there the nearly lagless transition to the monitor - at some point either a hardware or software scaling from 1080p to 1440p or whatever the monitor runs at might be needed also. Guess that explains my brain bust earlier on the capture card display port thing. Maybe in the future some capture cards will implement a passthrough with G-SYNCed / FreeSync DisplayPort.

[OUTferJUSTICE]

Scary oversight, sorry.

We don't know the monitor (always give exact details, please!) but the Framemeister won't fully upscale the image for final viewing unless it's just a 1080p panel - this might lead to very ugly effects. It's also unclear to me whether live preview would retain the apparent requirement that the source be true fullscreen (multiple sources: ]#1, #2). At least some capture preview programs won't do this, and it looks like G-SYNC on the desktop is still being locked down (the intended behavior seems to be that it default to G-SYNC off on the desktop). Finally, that seems like a hell of a long input latency chain: console to (optional?) Framemeister, capture card, PC data system to PC graphics rendering system and from there the nearly lagless transition to the monitor - at some point either a hardware or software scaling from 1080p to 1440p or whatever the monitor runs at might be needed also. Guess that explains my brain bust earlier on the capture card display port thing. Maybe in the future some capture cards will implement a passthrough with G-SYNCed / FreeSync DisplayPort.

If I were to use something like the 512N1, why exactly would I need a scaler? I mean, the 512N1 accepts 240p signals, right? My PCs Video Card would handle all the scaling. Is there a problem with the actual picture quality in preview mode with the 512N1? Sorry if I am misunderstanding something :-\

[Ed Oscuro]

On second thought, the monitor might display your content fine (if the signal is close to 60Hz and in range for the monitor) - it just might not be displaying it in G-SYNC mode, and there could be tearing or some lag, but probably nothing fatal. It'd be ideal to get captured frames sent to the monitor with G-SYNC active, but I'm not seeing a clear indication this will work. G-SYNC is worth getting to work in this case, but perhaps not essential and the drivers and support seem to be in a state of development.

You ought to tell us which monitor you have - whether it's 1080p or not might matter. I don't think Fudoh's mention of the Framemeister is out of left field here - if your final resolution is 1080p it probably will give the best quality scaling, though unfortunately it serves no other real purpose here. Personally I'd hope for "decent" scaling in the monitor or in Windows, as it works sometimes, and save the cash (it's a lot).

Ultimately you'll have to decide whether you want to spend a bit of money to be a guinea pig (the capture card route isn't necessarily too expensive, but still nowhere near free). Some more notes on the capture card route here. Shame about not having room for a regular tube - of course you could always think again about finding a thin flat tube TV, or a small portable, or a projector, or maybe a cheap second LCD.

[OUTferJUSTICE]

On second thought, the monitor might display your content fine (if the signal is close to 60Hz and in range for the monitor) - it just might not be displaying it in G-SYNC mode, and there could be tearing or some lag, but probably nothing fatal. It'd be ideal to get captured frames sent to the monitor with G-SYNC active, but I'm not seeing a clear indication this will work. G-SYNC is worth getting to work in this case, but perhaps not essential and the drivers and support seem to be in a state of development.

From What I gather, G-Sync should work as long as there is a fullscreen mode in live preview and it is hardware accelerated using ddraw/direct3d/opengl. Do you happen to know if there are any live preview programs that can be hardware accelerated (real-time filters would be a plus, too)? If so, will it retain the original refresh rate of the source? For Example: if I capture an SNESs output using the SC-512N1, will it retain the original 60.098hz refresh rate? If the card's preview is fullscreen AND it retains the original refresh rate, there might be a chance gsync may actually work with it.

I have an Acer xb270hu @ 1440p btw, sorry I didn't mention before. I had all my old hardware in a closet because I didn't have a display for any of it. Recently set up GroovyMame... and having it work with gsync is a total revelation. Perfect scrolling with not stuttering, minimal input lag at original refresh rates is just awesome. R-Type and Mortal Kombat finally feel right playing on an LCD. My experience with GroovyMame is really the reason I started thinking about using this monitor for all my old stuff.

Thanks for the help btw, Fudoh and Ed.

[Ed Oscuro]

From What I gather, G-Sync should work as long as there is a fullscreen mode in live preview and it is hardware accelerated using ddraw/direct3d/opengl.

That agrees with what I've read.

Do you happen to know if there are any live preview programs that can be hardware accelerated (real-time filters would be a plus, too)?

Don't know, unfortunately, hence my ambivalence.

If so, will it retain the original refresh rate of the source?

Another open question, given the safe assumption up to now is that computers will run at 60Hz, or some other fixed rate, without flexibility to shift as suits content. I hope this isn't true in some software.

Sorry I can't help much more. Any real tests you do here are pretty helpful.

Have you tried the Blur Busters forum? That site has a lot of knowledgeable posters concerning adaptive sync use and probably video capture as well.

[OUTferJUSTICE]

Looks like I'm gonna have to experiment! Alright, I'm probably going to get the card and post my results here. I have some other needs that the card will cover, so if I fail I'd still have use for the card. If I succeed, this would essentially turn my PC into a scaler that displays at the sources original refresh rate, and would also lead to the possibility for some able programmers to incorporate some HLSL filters and other real-time post processing if that isn't already available. More updates when I receive the card.

[alamone]

You could try using Dscaler. It can stretch the preview to fullscreen and apply on-the-fly deinterlacing.
For capture cards, just get the Startech version of the Micomsoft card if you have a free PCIe slot.

Personally, I'd just get a separate monitor for your retro stuff, even if it's just a LCD, put it on a arm mount.

[Fudoh]

If I succeed, this would essentially turn my PC into a scaler that displays at the sources original refresh rate

I don't see it, but keep us updated!