How to make Scanlines and CRT effects efficient ?

Andearoid

Hello,

I installed Batocera on a Thinkpad T61 (Core2 7100 + Intel 965 Express chispset) and anything works great except my favourite scanline filter to get CRT effect. To describe the issue, I don't see emulated scanlines on the screen but a mosaic effect. This means the filter is enabled but not working properly.

The LCD screen of this laptot is 1280x800. Perhaps the scanline filter doesn't support this resolution. So, is it possible to setup this filter ?

I also tried all CRT shaders, some of them have a very nice scanline rendering but the framerate slow down and games aren't playable. As example the Super Nintendo emulator run with the CRT Pi shader under 15 fps.

The laptop has a dual boot between Windows 10 (1803) and Ubuntu (18.04) and each one can run SNES9x with a very nice CRT effect at 60fps. Under Windows 10 the video engine use DirectX and under Linux it use OpenGL. This means hardware is competent. But I don't use .glslp files as shaders in SNES9X otherwise the framerate falls under 30 fps.

So is there any other method to filter the video into Batocera ? I'm running the 5.17 release with x64 support.

Andearoid

I didn't found solution for scanlines/CRT effect at now. I updated Batocera to 5.18 but it doesn't solve the shader issue on my Lenovo T61 computer. I suppose everyone use Batocera with a Raspberry Pi and an HD TV and everything works well with this hardware setup. So my question will stay orphan.

What shader effect are you using in RetroArch to get a more pleasant rendering on a slow computer ?

Andearoid

Finally I can get scanlines filter in Retroarch using Onscreen Overlay params. All games look better, retrieving their original graphics like their was made for by their games developpers. And it consumes 0% of CPU load instead of Shaders. It's not a CRT screen but it's a good compromise with a low CPU.

With Batocera you have to put your files (.png + .cfg) into :
/recalbox/share/system/.config/retroarch/overlay

The scanlines.cfg file content must be something like that :

overlays = 1
overlay0_overlay = scanlines.png
overlay0_full_screen = true
overlay0_descs = 0

And the .png file something like this :
http://i.imgur.com/rcaf5Tj.png

Perhaps you will have to scale or resize the scanlines.png file for your screen size. If it's not properly scaled, your scanlines rendering will looks ugly. So take your time.

Then to load the scanlines Overlay filter at startup you have to add this line to the config file :

input_overlay_enable = true
input_overlay = "/recalbox/share/system/.config/retroarch/overlay/scanlines/scanlines.cfg"
input_overlay_hide_in_menu = "false"
input_overlay_opacity = "1.0000000"
video_message_pos_x = "0.050000"
video_message_pos_y = "0.050000"

For example the Super Nintendo's emulator the path of its config file is :
/recalbox/share/system/.config/retroarch/config/Snes9x 2010/Snes9x 2010.cfg"

---- Additional tips ----

In Retroarch's options don't forget to enable "Reduce Slowdown" and "Reduce Flickering". And your Super Nintendo's games becomes just better than using the console's original hardware.

Andearoid

Hi,

I was looking about how to draw a pixel perfect scanlines overlay, and I fell on a thread about a CRT/LCD shaders specialy developed for the official SNES Mini (after hacked). Its hardware is much less powerfull than the Raspberry Pi 3 and the CRT Pi's shader slowdowns SNES games. Like my old computer.

So yesterday I tested this CRT/LCD shader called ZFast and it works pretty well. All my retro games runs at fullspeed. With this shader I can set scanlines blackness, blur/shine the pictures like a good old CRT television, fade pixels outlines. Take your time to set values and the result will be amazing.

You can download that shaders here :

https://github.com/ghogan42/common-shaders/tree/zfast_shaders

. zfast_crt_standard.glsl
. zfast_crt_standard_vertical.glsl
. zfast_lcd_standard.glsl

Denis, if you're reading this lines or able to read in my thoughts, you should use this shader as scanlines filter with Batocera instead of the default Retroarch Scanlines.glslp preset. Game designers were using this TV scanlines to give graphical/visual effects. So it's very important to get this filter working properly for a retrogaming operating system.