Unfortunately the exact crossing occurs at different times for different GtG combinations, and at different temperatures (hotter = faster). Don't forget the frozen/cold LCD knowledge too. So you've got a big engineering challenge to make the zero crossing occur simultaneously for the whole screen. You'll need 3D or 4D buffers (X times Y times multiple refresh history), and probably thermosistors, to keep track of how much ghosting is occuring where, and compensate for that, as well as using temperature information to create such precise voltage/timing information, to aim the voltage crossing at correct times for all pixels simultaneously. Ugh. Precise control of a wide voltage range.HeLLoWorld wrote:Schemes where the desired value is deliberately overshooted (ie does not settle to correct value but higher), but is correct (but still rising) precisely at the moment of the flash, and with different target values for top and bottom of screen (even if already using accelerated scanout)
HeLLoWorld wrote:(ie, bottom pixels overshoot more, because they must rise faster, because they are commanded later than top pixels).
HeLLoWorld wrote:So the whole screen changes at different rates
HeLLoWorld wrote:I guess the overshooting algos (like overdrive probably is) must be complicated enough to additionnaly take in acccout the value of the desired color of the individual pixel and maybe the previous value can be a valuable information too.
Yep! The GPU can process overdrive, it's already been done by AMD years ago:HeLLoWorld wrote:Thank you very much. By the way I was not planning to modify the refresh process myself.
However, while discussing this the other day, the idea came out that the processing could be done by the gpu instead, and the panel stripped off of a bunch of things, if the panel can declare its properties. Can't decide if it's elegant or ugly
HeLLoWorld wrote:so that fastest possible accelerated scanout is desirable, even for continuous backlight
HeLLoWorld wrote:No, I mean it creates the curtain effect
HeLLoWorld wrote:Effect 1. Let's say you've got a crt. It refreshes top-down. If you track a fast moving object, your eyes move while it draws, so it might appear compressed on your eyes if it's moving vertically.
HeLLoWorld wrote:Effect 2. Your eyes track a background moving left to right. your eyes have moved between top refreshed and bottom refreshed, but the picture is from the same moment in time. This must cause distortion in your perceived image.
HeLLoWorld wrote:This doesnt appear with strobing.
HeLLoWorld wrote:Something similar must happen on lcds refreshing top-down as slow as a frame, although this effect is maybe washed out by the constant backlight already, maybe it's something subtle that becomes significant only when constant backlight problem is solved (example: crts)
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