Editing Flicker fixer (section)

{{Short description|Video de-interlacer}}
{{Multiple issues|{{Confusing|date=February 2009}}
{{More citations needed|date=September 2024}}}}

[[File:Flickerfixer.jpg|thumbnail|External flicker fixer]]

A '''flicker fixer'''  or scan doubler is a piece of [[computer hardware]] that [[deinterlacing|de-interlaces]] an output video signal. The flicker fixer accomplishes this by adjusting the timing of the natively [[interlaced video]] signal to suit the needs of a progressive display for example a [[cathode-ray tube|CRT computer monitor]]. Flicker fixers in essence create a progressive frame of video from two interlaced fields of video.<ref>{{Cite web |date=2019-07-24 |title=AE display delay + UI flicker using dedicated GPU - Windows 10 |url=https://community.adobe.com/t5/after-effects-discussions/ae-display-delay-ui-flicker-using-dedicated-gpu-windows-10/td-p/10573170 |access-date=2024-09-11 |website=community.adobe.com |language=en}}</ref>

Flicker fixers [[sampling (signal processing)|sample]] the NTSC/PAL output from the output device and store each scan line from the field currently being displayed in [[Random access memory|RAM]] while simultaneously outputting the line alternately with the corresponding neighboring lines from the field stored previously (''[[Deinterlacing#Field combination deinterlacing|weaving]]''). Some more advanced flicker fixers integrated in add-on graphics cards use more sophisticated methods. Outputting the image at double scan rate essentially composes a progressive display with all lines from both fields at full vertical refresh rate. This promotes the horizontal [[frequency]] of the signal from 15.734&nbsp;kHz to 31.47&nbsp;kHz (in the NTSC case, numbers for PAL are slightly lower), which can be the used to drive a [[Video Graphics Array|VGA]] monitor from an output device.<ref>{{Cite web |title=Flicker Free Plugin : Deflicker Time Lapse, LED and Slow motion / High Frame Rate in HD and 4K :: Digital Anarchy |url=https://digitalanarchy.com/Flicker/main.html |access-date=2024-09-11 |website=digitalanarchy.com}}</ref><ref>{{Cite web |title=How to Fix a Flickering Screen with Intel&reg; Graphics |url=https://www.intel.com/content/www/us/en/support/articles/000026580/graphics.html |access-date=2024-09-11 |website=Intel |language=en}}</ref><ref>{{Cite web |date=2024-05-16 |title=Why is Your Screen Flickering and How to Fix it? |url=https://www.tesmart.com/blogs/news/why-is-your-screen-flickering-and-how-to-fix-it |access-date=2024-09-11 |website=TESmart |language=en}}</ref>