Here's my take on the whole thing.retrorgb wrote: When you filter an already filtered signal, it softens the image. That's why the THS7314 looks so good on RGB monitors and through OSSC/Framemeister with the filters turned off, but people say it's "blurry" in other situations. The stock S-RGB chip does not have a filter either, so using the 7316 or 7374 (filter off) will produce the same type of output as original, unmodded 1CHIP's....same with other consoles. It would be hard to have a setup with one SNES having a filter on and the rest with no filter. In most scenarios, it's better to deal with that on the head-end.
Analog input devices (PVM):
- The unfiltered "noise" (as Tim W. put it) is very fast moving spikes, coupled into the video signal. These spikes are too fast for analog devices, and they just don't "see" them.
Scalars (OSSC/PVM):
- These sample the input analog signal. They sample the input at much higher frequency; they see these spikes and assume they are valid data. Hence you see jailbars in output. So we need to have a LPF before the analog sampler to remove these spikes.
- In the case of OSSC that's easy - the LPF is user controllable
- In the case of XRGB mini - it's not. The latest firmware DOES NOT allow one to turn on LPF without introducing other video processing (linear/bob deinterlace!) - GAME1 mode turns on the LPF in XRGB mini - it softens the picture to look worst than THS7314 based solutions!
Digital displays:
- I think this is a non-starter (unless you have a digital display that takes as input RGB signal). By the time the signal hits my LCD, it's already gone through the XRGB mini and been digitized. LPF does not apply.
Other consoles:
- N64RGB uses the THS7374 - the LPF is enabled by default
- NESRGB - I see no issues on XRGB in picture mode - I assume LPF is enabled on NESRGB
- NEC consoles - latest kits have switched to using THS7374 - what happens with 1CHIP can apply here as well
- SNES - see this thread.
- Sega Genesis & others - I don't see jailbars on XRGB mini - I assume there's some sort of LPF in console (could be wrong)
Dilema:
- XRGB mini in PICTURE mode is the "recommended" solution that most use (It's what FBX sets most his profiles to!)
- At this point, there are a lot more XRGB mini users than OSSC - a solution is needed that works for them
- Unless one can point to a way to turn only LPF in XRGB mini - turning off LPF in THS7374 is not a good option in my opinion