Can anybody give me a hand with this ?
Recalbox 4.x on the Pi3 is quite capable. By default it offers two shaders: scanlines and retro. Scanlines look weird and it's still using some next neighbour scaling which causes scrolling artefacts. Retro is much better, but it's heavy on the CPU. For most systems it's fine with 720p output, but 1080p+retro already makes the PCE emu stutter and PSX is a no go.
Three things I would like to achieve: a) activate the pixellate.gls shader along with 1080p output, b) adjust or replace the scanline filter to look more like a FM with activated scanlines and c) lighten up the retro shader. The latter should be doable to removing the crt bloom portion of the shader.
UPDATE: ok, made a little progress already. Pixellate is in place. Runs fine in 720p, but the Pi3 is too slow to run it in 1080p (where it would really shine). Also the crt-caligari shader is ok, but I would like to increase the scanline opacity. Unfortunately Recalbox in general is missing the options to adjust the shaders. It just lets me access the raw gls code. If somebody could try the crt-caligari shader on a proper retroarch installation and find out which number is affected by the scanline density option I would appreciate it!