GroovyMAME LCD Noob questions

[ABTmRw]

Bought a Vewlix cab and want to use GroovyMAME because it has low input lag AND support for HLSL.  I'm playing the Tetris The Grand Master series and low input lag is needed to be competitive, but I also want it to look close to what it would look like on a CRT monitor.

Was following this guide to setup GM: http://geedorah.com/eiusdemmodi/forum/viewtopic.php?id=433

For LCD use, do I need to install CRT Emudriver or anything else besides GM?

I have GM up and running with the monitor set to lcd, but haven't really changed anything else.  Anything else I should configure before proceeding onto HLSL?

Any help is appreciated! 

[schmerzkaufen]

For LCD use, do I need to install CRT Emudriver or anything else besides GM?

Only if you wish/need to run the games at their proper real refresh rates, like if you had Gsync or Freesync but without the name brands on your hardware. But that requires a compatible LCD (and not all of them are, only way to know is to test by creating a few custom resolutions like 55Hz, 56, 57 etc using nVidia/AMD control panel, and see if your monitor displays them fine and without forced buffering/conversion)

TGM is 60Hz, TGM2/p is 61.68Hz, so unless you absolutely want to play 2 at its exact refresh rate you don't need Emudriver.
You could just create a 61Hz mode (like its done in the nvidia/amd control panel) to get slightly closer if you want, that wouldn't be accurate but still not require Emudriver (would still require your LCD to accept 61Hz though)

Anything else I should configure before proceeding onto HLSL?

You can use Frame Delay (TAB > sliders menu) to further reduce lag, but on LCD that often means you may see tearing, and will have to use the vsync_offset setting in conjunction with frame delay.
Typically: create one gamename.ini per game, and set a value that will eliminate that tearing.

Note you should do this AFTER setting HLSL, otherwise it'll throw off your vsync_offset settings.

It's not complicated when you got how it works and if your PC is reasonably strong, because frame_delay and vsync_offset (as well as HLSL) all add their own CPU & GPU cost.

This is GroovyMAME's Achille's Heel when it comes to mainstream/lcd usage, as typically new users can't manage to make that frame_delay + vsync_offset duo thing work and they give up.

BUT even without Emudriver, without custom modes, without Frame Delay, Groovy still features smoother scrollings (for the games that aren't too far off 60Hz), and slightly lower lag than baseline MAME, all by default.
So even if you don't use any of the special features you still benefit.

PS and this is my last edit: you can also look into Portaudio to reduce audio lag, after all in many timing-critical games sound effects matter too. Of course Portaudio too spends its own share of CPU power.

[ABTmRw]

Thanks for all the info!  It has been very helpful!

I'm using my desktop monitor to setup my MAME PC, but once I have my Vewlix setup, I'll play around with my monitor to see what I can do.

[schmerzkaufen]

If you ever go as far as using Emudriver, would the vewlix's monitor allow it, then you'll need this guide, which you may already know about but here it is: http://geedorah.com/eiusdemmodi/forum/viewtopic.php?id=374
If the VLX's monitor isn't compatible, a monitor like mine is (check my sig), but it doesn't come 'ready to install' in a lcd cab, that's be too good. There are more ViewSonics like it btw, working with Emudriver.

That'd be alot of investment and effort just for playing TGM on a lcd cab, but I know some people take their Tetris very seriously. ^^

[ABTmRw]

If you ever go as far as using Emudriver, would the vewlix's monitor allow it, then you'll need this guide, which you may already know about but here it is: http://geedorah.com/eiusdemmodi/forum/viewtopic.php?id=374
If the VLX's monitor isn't compatible, a monitor like mine is (check my sig), but it doesn't come 'ready to install' in a lcd cab, that's be too good. There are more ViewSonics like it btw, working with Emudriver.

That'd be alot of investment and effort just for playing TGM on a lcd cab, but I know some people take their Tetris very seriously. ^^

The monitor I'm using is this one 32MA70HY-P.  This product allows people to install a lot of different monitors inside their Vewlix:

https://www.hadouken-arcade.com/product/pre-order-vewlix-universal-monitor-bracket-batch-2

If I knew the information you provided me, I would have looked for a monitor with G-Sync and a more powerful PC, so I could do Frame Delay 9, but as it is, the emulation seems pretty good with Frame Delay 4-5 with no screen tearing (or I can't see any).

Yes, I take my Tetris seriously! 

[schmerzkaufen]

https://www.hadouken-arcade.com/product/pre-order-vewlix-universal-monitor-bracket-batch-2

Oh, universal mounting, so convenient. ^^

If I knew the information you provided me, I would have looked for a monitor with G-Sync and a more powerful PC, so I could do Frame Delay 9,

If you have a G-Sync or FreeSync setup you don't need Frame Delay! 

Groovy produces no lag when in 'hands off' mode as I like to call it, that is when autosync (and any other sync option if you have to make sure) is turned off, which is what is required for Gsync or Freesync to work as intended.
Baseline MAME received the same ability recently wih the 'low latency' option (which means what I just explained: no lag when using a VRR setup), thanks to Calamity again.
Playing in VRR also doesn't spend any extra CPU/GPU resources, unlike frame delay.

Emudrivers and Frame Delay on LCD/flatpanels are meant for setups not officially supporting VRR like gsync or freesync, but still able to do something similar under certain conditions (like again some ViewSonic monitors and a unknown number of others on Earth), it is a very niche case scenario, more complex to set up than just firing Gsync/Freesync...it is a bit tricky 'home-made VRR' for free. 
(Calamity called that 'bleeding edge old tech' iirc)

but as it is, the emulation seems pretty good with Frame Delay 4-5 with no screen tearing (or I can't see any).

Yeah even modest frame_delay levels can make gameplay feel very responsive.

The matter of tearing though...[rant extension warning] well, it's always a stressful question. I can't tell anything without seeing your full configuration (generated log & mame.ini), and even if you showed both I'm not really the best person here to spot every possible issue that would be obvious to the handful of power-most users around, but in general when users in a LCD case scenario say "I can't see any tearing" I always can't help but first suspect something is wrong.
Why? because I have built a lot of experience using Groovy on flat panels so I'm kinda used to how the beast behaves in that particular niche area of use. Most Groovy users you'll meet, save for Calamity himself, only experienced on CRT 99% of the time. Rules for flat panel displays are in large parts similar but the forces weighing on the system definitely not the same league.

-There can be situations where a manner of vsync superseding Groovy's is forced over (misconfiguration, sync forced by OS in windowed or non-exclusive fullscreen), in which case the features intended by Groovy are not actually working.
-Or the settings are right and the intended autosync behaviour active, but the CPU+GPU combo powerful-enough and the monitor's resolution low-enough, like for instance a 720p TV instead of a 1440p monitor (= factors that matter a ton more than with CRTs), so that the tearing line is there but very small and you won't notice it, even less over HLSL with simulated scanlines that might hide the tear line, or not at all in a scrolling-less game (like Tetris) where vsync doesn't matter much.
-Another quite revealing case of smth being wrong is when people say they can easily push frame delay to 9 in every game (which btw isn't desirable because often counter-productive for lag), it either means Groovy is not working at all, or that they have stolen a supercomputer from NASA.
-Many casual users don't get the meaning of autosync and sync_refresh_tolerance relationship, and how important that is for the effectiveness of frame_delay. The default settings in Groovy make the main features like smooth sync and frame_delay work only for games that are natively between 58Hz and 62Hz, outside of that range a triplebuffer is used and neither smooth sync nor lag reduction will work anymore. You are not concerned with TGM games bu that's just another case to illustrate.
-etc yada yada
[end of rant extension] 

My advice if you don't mind unreasonable spending: get a Gsync of FreeSync setup: it is accuracy and laglessness without hassle.
It is a big expense if just for TGM2/P, but heh, a stronger CPU/GPU for getting higher frame_delay is expensive too. Pick your poison.
Note: beware of 4K monitors (or of any other resolution) that support gsync/freesync BUT are capped to 60Hz. Just avoid those, you want VRR that goes beyond 60Hz, like 75Hz at minimum, it is mandatory for 61+Hz games like TGM2/p.
I haven't looked into 32" options in a long time so I can't recommend models right now.

Realistically I am probably the only one around here or anywhere else using a fully-featured Groovy+Emudriver LCD setup, it's awesome and accuracy-wise wipes the floor with any other MAME build or other arcades emulator (don't even mention RetroArch), as long as gsync/freesync are not options, which was my situation.
But this unconventional 'path' currently is still only meant for power users who don't own/want to pay for fancy nVidia nor AMD techs.
Come back maybe in 2021 if you want a more user-friendly version of GroovyMAME that is AFAIK in development, and should make using LCDs/flatpanles much easier.

Yes, I take my Tetris seriously! 

[ABTmRw]

Thanks, that's very helpful.  What you say makes sense.  Luckily, TGM and TAP seem responsive enough with HLSL and Frame Delay.  My main goal is to be able to improve my Grand Master rank time.  If I feel like the hardware is holding me back, I may have to upgrade.

Come back maybe in 2021 if you want a more user-friendly version of GroovyMAME that is AFAIK in development, and should make using LCDs/flatpanles much easier.

Glad to hear it!  I may be buying more Vewlixs in the future so this is good to hear.

[schmerzkaufen]

Allow me a FREE MAD BONUS RANT on monitors, since I think I can get a flavour of A-P community here    (whenever ppl talk about lcd cabs in the english language it often converges towards their forums)

That community has for some time had a belief the LG 32MP58 is a good monitor to put in LCD cabs...but it is very inferior to the ViewSonic VX3211-mh I'm using (a.k.a VX3276-mhd in the US or VX3276-mhd-2 in other parts of the world with different looks and added DP input)

It's the same panel and same lag (3ms top bar Leo Bodnar*) but firmware/software-wise, compatibility and quality-wise they're quite different.
- the ViewSonic can display any native **.**Hz frequency between approx. 50~75Hz from a PC source, no lossy framerate conversion, it is compatible with Emudrivers which makes it ideal for MAME (reminder; as we discussed: understand in a situation where the owner doesn't want to upgrade to Gsync/Freesync, of course)
- it pairs fantastically with the OSSC not refusing any source nor output mode (even x5 displays pixel-perfect)
- features a never greyed out (rare!) overcan setting that can zoom the picture about 10% and therefore eliminate black bars/borders at any time with any source (not thru the VGA input tho, only HDMI/DP) so gone the annoying borders with a PS2, MD/Genesis or whatever other source that would display by default with borders. The aspect ratio settings also work fantastically anytime but the default setting is so good you don't need to touch them. Overscan option in the menus however is not easy to reach, if the monitor's trapped in an enclosure it might be a problem, but the option exists anyway and trust me it is a rare one on a monitor, typically only TVs feature that kind of zoom.
- accepts DOS 70Hz as well lol
- built-in scaling is good quality, pixel response is also good w/ mid-overdrive.
- VX3211-mh version is built sturdier, while the VX3276-mhd thin bezels look more fragile.

NB: don't mistake them for WQHD models that have '2K' in their name, nor assume these 2k or 4K variants are the same technically and performance-speaking. All I've said is valid only for the three Full-HD model variants I posted about. there are other VS monitors with similar abilities, but it'd be too long to talk about that here where my rants are long-enough already.

CLOSING POINT: the LG is an okay choice for ppl who will play only HD sources in their cab, but it fails at everything else. For anyone who also wants to play everything older than 480p/720p/1080p, for getting accurate emulation with Groovy+Emudrivers, or an excellent OSSC experience, then the ViewSonic's vastly superior in all aspects (assuming again no Gsync/Freesync purchase instead)
There may be more attractive 32" monitors these days featuring proprietary nVidia/AMD VRR but I haven't looked closely into the market, don't need to since the VS is such a rare kind and been a do-it-all blessing, all I know is what I just said about the LG and ViewSonic that I have tested myself, and for sure @ +/- 200 bucks going for the LG instead of the VS is silly.
It's not just at AP, there's a couple more arcades-related forums where I've noticed the LG 32MP58 word has spread, and when ppl get ONE bit of working info from someone they'll definitely stick to it forever, never trying to look elsewhere they'll ignore better alternatives until the product goes EOL. I think it was last year or end 2018 I've seen the VS sell as low as 175€, yet a couple dudes looking for a monitor for their cabs still went for the LG that was like 250€ at that same time. *sigh*





* Yes many ppl would measure 8~10ms like they did for the LG, but they'd wrong because no, the middle bar measurement they all look at is not the 'actual input lag period' contrary to the widespread - wrong - belief, it's really input lag PLUS the middle/halfway time of the frame being drawn, and whether on crts or lcds the amount of time that's part of the normal 16.6ms (@60Hz) expected drawing/scan time was never, ever, to qualify as lag/delay. If we listened to the middle bar advocates flawed logic then according to them all crts lag by 8.3ms @60Hz too!...they simply don't understand because they just mimic and repeat according to the most popular opinion. Anyway, just wanted to make that clear.
The LG and ViewSonics mentioned in this post are sub-3ms lag diplays, which is actually quite common these days even the lowest end models any name brand can be practically lagless.

[ABTmRw]

This info will definitely come in helpful for people who want as close to best as possible on their LCD monitors!   

[schmerzkaufen]

Had a look around current/newer available 32" monitors, choices are plenty, Full-HD with FreeSync in the ~200 don't break the bank.

Now quality and performance, and more importantly specs can make one fantastic and the other useless.

That's material for later investigation.