Fuse has a series on video filters available - scaling/simulating the video output on a TV, etc. Try one of those filters (TV x2 seem to simulate a CRT scanline display).
Not sure of Zesarux has more advanced options, you could give it a try.
@sad_muso you didn't say what emulator you're using. afaik even simple shaders are often very system bus intensive, so they're constantly fighting for bandwidth with the GPU, CPU, etc. afair, lr-genesis-plus-gx really hammers the system bus, so try using lr-picodrive instead, if you're using the former.
Are they CPU/RAM intensive or both? Does the Pi 4 cope with shaders better than the 3 B?
first part answered above. pi 4 will cope better.
Do overlays cause any hit on performance, specifically when used in conjunction with shaders?
yes, for whatever reason they seem to.
What is the least expensive way to implement curve and scanlines that is currently in existence?
Regarding the 117Hz display, I'm not sure. That number is actually computed from pixel_frequency timings so maybe is dependent on the current GPU clock. Are you using a good power supply?
Regarding the flickering, I have zero experience on using the composite out and CRT, so can't help you much there. Sorry! But yes, it does seem like having 117Hz instead of steady 120Hz can be the issue as you gradually get out of sync for the black frame insertion.
i dont know what happend with this amazing emulator, but since some update it plays games with those disgusting scanlines which are completly gamebreaking for me. is there any way to turn this shitty scanlines off ? i cant see any option related to it in F12 menu.
thank you in advance
Assuming we're talking about the same visual affect, turning off Line Doubling in the Display section removed those scanlines for me.
I use HDMI to VGA at 640x480 too. Every emulator or even game can have its own resolution. I enabled the RunCommand launch menu and selected for each system (DMT-4 and 5 means 640x480). I don't know if I forgot something, but here it is.
RunCommand launch menu:
Select default video mode for "SYSTEMNAME" (DMT-4)
Select RetroArch render res for "SYSTEMNAME" (5)
Then you can disable the RunCommand. I also set the resolution of EmulationStation itself through the file
Ok, so after I wanted play some games now, I realized the bottom part of the lr-snes9x games are always black. I can't say how many rows, but maybe 10th. The other sides are all on the edge of screen and Emulation Station is shawn correct, lr-nestopia too. Is there a setting I miss? The strange thing is, in RetroArch menu the whole screen is used. The emulator makes the image of game smaller and shows a black bottom border only.
EDIT: Ok so, after quick testing, it happens also in PC Engine, but not the other emulators.
I also have the pi2scart ouputting on a 28 inch consumer crt from philips and dont have those "problems". I cant even take photos of my scanlines becaues they are so subtile. Would like them a bit more beefy to be honest but its not that easy to get a pro crt here sadly.