Changes

'''NTSC filters ''' replicate the analog signals that the consoles output to the TV. They vary in quality, with the lowest quality being RF, then composite, then s-video and RGB (SCART)/YPbPr (Component) being the highest quality. Many emulators have NTSC filters built into them. They can also be separately downloaded as filter plugins. These filters were developed by [blargg<ref>http://slack.net/~ant/libs/ntsc.html blargg] (Dead?)</ref> for specific consoles. Other NTSC shaders have been created which are different from Blarggblargg's implementation.

Encoding ''luminance '' (or ''luma'', the brightness component of the signal) and ''chrominance '' (or ''chroma'', the color component of the signal) into a single signal is what causes blur and artifacting because it's a lossy way of encoding an image. RF is has worse artifacting because it also encodes audio into the signal and is more prone to interference since the signal is the same as what was used TV broadcasts.

The level of blur in RF and composite signals are needed for [[dithering]] to blend on Genesis/Mega Drive. S-video, and RGB are too clean to blend dithering. Other shaders can be used to achieve the same level of blur.  Many SNES games were developed with the color distortion from these signals in mind, such as Chrono Trigger, with shifted values that make blacks look brown and borders look purple (this is due to TV color range being 16-235, as opposed to standard PC color range of 0-255), which would be output properly with NTSC colors, and Kirby's Dream Land 3, with vertical line patterns combined with high horizontal resolutions producing translucency effects when blended by the analog signal. Other games like Sonic used [[dithering]] patterns that would be blended on the Genesis/Mega Drive composite output, which is notably blurrier than NES or SNES composite video.

Higher quality than RF, but still blurry and with lots of color artifact and dot crawl due to crosstalk between luma (brightness component of the signal) and chroma (color component of the signal). This is what most systems used as default.

Much cleaner image due to luma and chroma being separate signals, though color blur still present and signal bandwidth chroma resolution is about the same as composite.

===Blargg blargg's NTSC===

Blargg'''blargg's NTSC shaders ''' filters are powerful and optimized, but they are very system specific. There is a version for NES, SNES, SMS, and Genesis/Mega Drive, and each is intended for that system only, expecting a certain size input resolution. Certain games on other systems than the intended one can still make use of them, but not without glitches. For instance, on certain [[PS1]] games that have multiple resolutions, some of the resolution modes will work properly with these filters, and some won't. This may mean the aspect ratio is horribly messed up for menus, but the main gameplay will look normal. These filters upscale the image wide horizontally, but don't touch the vertical scale, so 1:1 PAR may result in weird aspect ratios. The level of blur in RF and composite signals are needed for [[dithering]] to blend on Genesis/Mega Drive. S-video, and RGB are too clean to blend dithering.

['''Maister NTSC''' is a set of NTSC shaders<ref>https://github.com/libretro/common-shaders/tree/master/ntsc https:<//github.com/libretro/common-shaders/tree/master/ntsc] ref> created by Themaister created a set of NTSC shaders for use with various emulator cores in [[RetroArch]]. These try to be more "generic" than Blargg's filters, so they will work with any resolution without major glitching. There are several presets that cover different methods of generating composite and s-video signals.

Among the presets, there are Composite and S-video versions. Composite has all the fringing artifacts that oscillate every other frame, resulting in a slightly flickery image, while S-video simply has color bleed and blur. This shader lacks the sharpness filter that Blargg's NTSC filter has, so some may perceive it as blurrier, but it also lacks the ringing artifactscaused by a sharpening filter. There isn't much tweaking you can do besides changing gamma, since the effect is quite complex and difficult to understand. Increasing the horizontal scale of the output of the shader from 4x to 6x will decrease the intensity of the effects (which also increases sharpness). It does not have an RGB preset, though that's covered by another shader that emulates signal bandwidth. ===GTU=== '''GTU''' is a CRT shader<ref>https://github.com/libretro/common-shaders/tree/master/crt/shaders/gtu-v050</ref> by aliaspider that has options for emulating signal bandwidth in addition to the CRT scanlines effects. In addition to luminance (Y) signal resolution settings, enabling the "composite connection" option will allow tweaking the chrominance (I and Q) signal resolutions as well while emulating color bleed from low chroma resolutions.

There isn't much tweaking you Since the shader is multipass, the signal bandwidth emulation passes can do besides changing gamma, since be decoupled from the effect is quite complex CRT scanline emulation pass and difficult to understand. It does not have an RGB preset, though that's covered be used with other CRT shaders or by another shaderitself.

===Tvouttvout-tweaks===

['''tvout-tweaks''' is a shader<ref>https://github.com/libretro/common-shaders/blob/master/crt/shaders/tvout-tweaks.cg https:/</github.com/libretro/commonref> made by aliaspider, based off GTU, intended for processing emulator images for output to a CRT TV connected to PC via VGA-shaders/blob/master/crt/shaders/tvoutto-tweaksRGB adapter. This shader uses code from the GTU CRT shader to provide emulated signal bandwidth blur, as well as TV color level conversion. This shader is equivalent to the Blargg's NTSC filter RGB preset when the signal resolution is set to a high level and TV color levels are enabled. Works with any resolution without issues, lower signal resolutions result in blur that blends higher input resolutions, allowing dithering to be blended and SNES hi res translucency to work.cg]

A shader made by Aliaspider intended for processing emulator images for output to a CRT TV connected to PC via VGA===GTU-to-RGB adapter. This shader uses code from the GTU CRT shader to provide emulated signal bandwidth blur, as well as TV color level conversion. This shader is equivalent to the Blargg's NTSC filter RGB preset when the signal resolution is set to a high level and TV color levels are enabled. Works with any resolution without issues, lower signal resolutions result in blur that blends higher input resolutions, allowing dithering to be blended and SNES hi res translucency to work.Famicom===

'''GTU-Famicom''' is a variant<ref>https://github.com/libretro/common-shaders/tree/master/crt/shaders/GTU-famicom</ref> of the GTU CRT shader that emulates the NTSC NES/Famicom PPU. It requires the "raw" palette option in Nestopia and FCEUmm [[libretro]] cores, which outputs<ref name===Other==="nestopia_raw">https://github.com/rdanbrook/nestopia/commit/9d58851a22eb3baeee7b4fe28ae8ffaac7eaa599</ref> chroma, level, and emphasis as red, blue, and green color channels. GTU-Famicom takes that output and processes it as an NTSC signal, which the shader decodes into RGB colors for display. The shader also emulates the full effects of RF/composite NTSC video signals, complete with artifacts, fringing, and color bleed, and optionally RF signal noise. Like with the GTU shader, the various signal resolution paramaters can be tweaked so it can be made sharper, or made to have less color bleed by boosting chroma resolution.

* [https://github.com/libretro/commonAs with GTU, the GTU-Famicom shader is multipass so the Famicom NTSC emulation passes can be decoupled from the CRT scanline emulation pass and be used with other CRT shaders/blob/master/crt/shaders/snes-hires-blendor by itself.cg snes-hires-blend.cg]* [https://github.com/libretro/common-shaders/tree/master/dithering dithering shaders]

===Blargg blargg's NTSC===

Many The following emulators have them blargg's NTSC filter built -in. 

| style="text-align: center;"|✓| style="text-align: center;"|Win32 version has sliders.

| style="text-align: center;"|| style="text-align: center;"|Presets only.