GenPlus NTSC Filters

My personal favorite filter/shader combination is cgwg’s CRT shader together with blargg’s NTSC-RGB filter. Unfortunately, the available SNES version for RetroArch of the latter doesn’t work for cores with a different resolution, e.g. the GenPlus GX core. Compiling the core with the NTSC flag did not produce the result I wished for and resulted in scaling errors for some ROMs (e.g. the Genesis version of Addam’s Family).

To get the result I wanted, I ripped out the NTSC filters from the original GenPlus GX project (based on blargg’s library and modified by EkeEke) and created a set of separate filter DLLs for the monochrome, svideo, composite and rgb variations.

You can find the source code and compiled 32 and 64 bit binaries for Windows on the GitHub repository I created for it. I hope these are useful for others looking for Genesis and Master System filters.

These are pretty cool, although the Genesis version of composite isn’t bad enough. :stuck_out_tongue: But they do their job.

All joking aside, out of curiosity I tried them with PS1 games, and they actually work without fudging the aspect ratio, although with mixed results. The Genesis versions look really weird with them and produce strange color effects and behavior, while the Master System filters work much better with PS1, although I’m not sure the resulting colors are authentic, particularly darker ones. But hey, they were not written with PS1 in mind, so this doesn’t surprise me. Just thought I’d share this.

The next version of Genesis Plus GX libretro will have blargg’s NTSC filter built into the core and it will be a runtime option. You will be able to disable or enable it using RGUI or RMenu - you can also choose between monochrome, composite, S-video and RGB.