Help loading GR, HGR, DGR AND DHGR image files in the Apple II

[joevt]

Are there any conversion programs that emulate a color composite display's NTSC interpretation of the Apple II's 14MHz square wave by emulating the analog circuitry or at least performing the same signal transformations?
https://codeandlife.com/2012/10/09/composite-video-decoding-theory-and-practice/
http://www.kreativekorp.com/miscpages/a2info/munafo.shtml

Found this:
https://www.reddit.com/r/software/comments/hh0pt8 which points to:
https://www.reenigne.org/misc/ntsc.zip
which exists on GitHub at:
https://github.com/reenigne/reenigne/tree/master/ntsc

It has two command line executables avi2ntsc.exe and ntsc2avi.exe.

ntsc2avi.exe converts 8 bit PCM 14.318MHz sampled composite video to AVI using FFTs, etc.

It should be simple enough to generate the source samples from the Apple II video buffers. I don't know how well it works or what the results look like.

I suppose you could use avi2ntsc.exe to create some test data for ntsc2avi.exe and to see what the source samples from the Apple II should look like (the sync and color burst parts - everything else comes directly from Apple II memory).

For an Apple II emulator, the ntsc2avi scan line code should probably be converted to a pixel shader.