Possible to simulate NTSC dot crawl via filters?

[FeelsDuckMan]

Topic says it all. I'm curious if it's possible to replicate the NTSC dot crawl effect using Mister filters.

[darksakul]

The visual artifacts caused by noise and distortion?

Why?

The Entirety of the Retro Community been trying to get away from dot crawl and rainbow artifacts
Even the CRT Purists

[caad]

Yeah but many CRT purists love the *gaps* between scanlines, so emulating dot crawl isn't that crazy.

[FeelsDuckMan]

The visual artifacts caused by noise and distortion?

Why?

The Entirety of the Retro Community been trying to get away from dot crawl and rainbow artifacts
Even the CRT Purists

Why even reply if you don't know? Your entire reply contributes nothing and is flat out wrong. If this were the case, none of those composite blend and Gaussian blur filters would even exist on the Mister. I don't care if you don't like it, I just want to know if it's possible to implement.

[Fallon]

Just tried Reshade Retroarch CRT effects on MAME and it almost makes me think of selling my Mister. Totally atmospheric, it feels like gaming behind glass. I love all the crazy artefacts it can do. The rolling screen distortion is crazy!

[FeelsDuckMan]

Just tried Reshade Retroarch CRT effects on MAME and it almost makes me think of selling my Mister. Totally atmospheric, it feels like gaming behind glass. I love all the crazy artefacts it can do. The rolling screen distortion is crazy!

Yea, I'm guessing it won't be possible because the Mister doesn't use shaders to simulate the affect, just filters to post process the video image, it's not doing anything dynamically. Unfortunate, I'm grateful for what we are able to accomplish however, the Mister has come a long way.

[Swainy]

Why not just use a CRT?

[FeelsDuckMan]

Why not just use a CRT?

Why not just use real hardware?

[caad]

Scanline filter? Who needs one?

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[darksakul]

The visual artifacts caused by noise and distortion?

Why?

The Entirety of the Retro Community been trying to get away from dot crawl and rainbow artifacts
Even the CRT Purists

Why even reply if you don't know? Your entire reply contributes nothing and is flat out wrong. If this were the case, none of those composite blend and Gaussian blur filters would even exist on the Mister. I don't care if you don't like it, I just want to know if it's possible to implement.

The first question is rhetorical. But I guess that went over your head.
My reply addresses the ridiculous of your request.

Composite Blend and Gaussian blur isn't the same as dot crawl.
One simulates the color blending on a CRT, the other (what you asking) is noise on the line.

Just convert your video down to composite video and use a dollar store RCA cable if you want Dot crawl.

[green_onion]

I've been hoping that something like the blargg NTSC filters would make their way to console cores in MiSTer.

I've seen some arcade cores with an "old TV" setting that actually outputs through VGA as well, although they'd probably be even better suited for console cores rather than arcade ones.

The visual artifacts caused by noise and distortion?

Why?

The Entirety of the Retro Community been trying to get away from dot crawl and rainbow artifacts
Even the CRT Purists

I highly associate the dot crawl and rainbow artifacts with giving the NES/Famicom in particular a more complete look. Maybe it's the influence of nostalgia from the days of playing the system over RF or composite, but the cleaner you make an NES game look, the more sterile, more "artificial" it becomes. Raw pixel NES games simply don't look like NES games to my brain.

Even in Retroarch, blargg NTSC filters coupled with a decent CRT shader really helps sell a pretty convincing facsimile of playing NES games on a vintage TV.

I primarily use my MiSTer on a PVM over RGB, and in most cases, for most cores, I want the cleanest, sharpest output possible on a CRT. But for NES games I would absolutely use NTSC filters with my PVM.

[FeelsDuckMan]

The first question is rhetorical. But I guess that went over your head.
My reply addresses the ridiculous of your request.

Composite Blend and Gaussian blur isn't the same as dot crawl.
One simulates the color blending on a CRT, the other (what you asking) is noise on the line.

Just convert your video down to composite video and use a dollar store RCA cable if you want Dot crawl.

Again, I don't care about your thoughts and opinions, I wanted to know if it's possible.

[jlancaster86]

I wouldn't expect video filters to get much more sophisticated on the DE10-nano; it has no GPU.

Remember: the cores don't even support basic bezels/borders because they'd be too taxing.

[FeelsDuckMan]

I wouldn't expect video filters to get much more sophisticated on the DE10-nano; it has no GPU.

Remember: the cores don't even support basic bezels/borders because they'd be too taxing.

Yea, I began to realize this after making this thread and looking into how filter files were created. Unfortunate, but I'm still happy we're able to enjoy what we do have.

[jlancaster86]

I've already posted this in another thread, but a new retro gaming scaler with and HDMI input has been announced. I haven't seen any mention of specific MiSTer support, but features include slot masks and smoothing filters for HDMI-modded consoles. It could potentially offer more than the DE10-nano alone can.

[aberu]

Topic says it all. I'm curious if it's possible to replicate the NTSC dot crawl effect using Mister filters.

Possible? Sure.

Practical, worthwhile, desirable? No.

Sorry to be a bit brief, but I doubt this will ever be implemented, it's a waste of logic space and will increase the complexity of achieving timing upon compilation for basically zero benefit. Some cores are pushing the capabilities to the edge, and adding more things to the framework need to be very carefully considered.

[ericgus09]

It might be do-able with external hardware "ala those external scanline generators" you would see prior to them being generated by the mister itself, .. I dont know of any such devices right now but I can't see any technical reason one couldnt be created along the same lines as the external pass-thru scanline generators but do dot-crawl type effects ...

[darksakul]

Again, I don't care about your thoughts and opinions, I wanted to know if it's possible.

Theoretically sure, but you have to make major sacrifices. The DE 10 nano has no GPU, which means losing more critical features elsewhere.
The ARM CPU is only 800mhz do don't expect anything from that.

In Practicality, I am happy to say it's not worth the effort.

Plus I don't see any Dev that wants to spend the time doing something so stupid.

As I said again, you want Dot Craw get a old TV maybe convert the image back to RF while you are at it.

[darksakul]

I've already posted this in another thread, but a new retro gaming scaler with and HDMI input has been announced. I haven't seen any mention of specific MiSTer support, but features include slot masks and smoothing filters for HDMI-modded consoles. It could potentially offer more than the DE10-nano alone can.

I doubt PixelFX would waste time with Dot Crawl Artifacts.

[kalach.x]

Composite Blend and Gaussian blur isn't the same as dot crawl.
One simulates the color blending on a CRT, the other (what you asking) is noise on the line.

NTSC dot crawl has nothing to do with "noise on the line" (whatever that even means) but color encoding and its limitations.

One RCA cable would be perfectly able to support even 1080p with full chroma let alone 240p/480i with full chroma but the so called Composite video just carries the standard NTSC/PAL signals and with it inherits all the limitations which were imposed on these video/color encoding standards. It made sense to have these limitations in order to limit bandwidth of each video channel and then it made sense to not have two color encoding standards and ridiculously complex and expensive video decoders in TV sets but just to use the same video signal.

It has nothing to do with any noise. One doesn't even expect to pick up any noise with Composite connections unless maybe you use cheap cables which weren't even designed for audio, let alone high bandwidth video.

Just convert your video down to composite video and use a dollar store RCA cable if you want Dot crawl.

This should work. Convert RGB output from Mister to Composite and then use something like RetroTink to convert back to HDMI or use Composite input on CRT. Universal solution which should work with all 240p capable cores and give superior results. I mean nothing gives better NTSC chroma dots than encoding signal to NTSC

And while mentally tinkering with this Mister could be made to modulate signal to NTSC and if it had this ability then it could be made to demodulate such signal (even without it going outside digital domain!) and this would yield the same effect but with better fully digital quality

No need to use silly shaders and FPGA resource costs would be much lower. Not zero because of need to use LUTs to store sinuses and do filtering and whatnot but much less resources than having filter system enough to execute fancy shader effects. Besides these shaders look hardly like real NTSC anyways. They "wow" people because the kind of people who use these shaders and can be "wow"ed do not use real NTSC.

@green_onion
I have the same thing.
More modern systems, especially those which already have lots and lots of colors like Amiga, SNES, etc. seem just fine with RGB but for NES it just doesn't look right to have this sharp of an image. But it is not only NES, also other low color count systems like C64 look way too clean with RGB.

NES RGB issue I solved easily with Twin Famicom and Evedrive N8 Pro and did so even before getting Mister so NES core even with its fancy save state feature is not something I would actually use except maybe foir Dendy/PAL timings, up-scaler and to have reference for how RGB NES looks like. IF you do not own it I highly recommend getting NES/Famicom and Everdrive N8 Pro