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Green screen flickery film artifacts3/25/2023 ![]() ![]() The problem is simply because ATI drivers set 2D clocks too low (157Mhz Core,300Mhz memory). Late to the party, but it may prove useful: Of course, it could have just been a dodgy connector in the cable (I tried both graphics card outputs so nada there.) I do not understand enough about it to form a firm idea of why it might cause the problem. My flickering was worse in particular areas, with there seeming to be some correlation between a group of dark and light mixtures making a "flicker" more likely to happen. I have a suspicion that the somewhat non-random nature of the problem is somehow also related to the 8/10b encoding which tries to achieve DC balance in the signalling protocol. Now the kicker is that these errors will not be completely consistant due to the source sometimes managing the job and sometimes failing. Too many bit errors lead to a pixel error and thus the pixel gets the wrong value and appears to be the wrong colour. If the source is unable to completely and consistantly sink the current in the wire then by the time the destination is reading the bit pattern it may be that it reads a 1 where there should be a 0, causing a bit error. This is where my "weak graphics card" hypothesis comes into play. A longer (and lower quality) cable will have a higer resistance and thus mean that the source must work marginally harder to pull the line low. My wild guess is that due to the DC coupling at the destination the source must effectively "sink" the current out of the wire in order to produce a valid "0" on the line. ![]() TDMS, according to wikipedia, uses " current mode logic (CML), DC coupled and terminated to 3.3 Volts" The effective signal path between transmitter and receiver looks something like this: I've tried to look into what might have been causing this issue for me and so here's my disclaimer for the next bit: Here be dragons and wild guesses as to what is failing.ĭVI (and HDMI) use TMDS. I'm not completely sure why, but this completely got rid of my flickering pixels. I can only assume that due to the age of my graphics card and the questionable nature of the long cable that data signals for darker areas were somehow corrupted, perhaps something about weak signals and the 8/10b encoding. I tried a number of things including changing screen resolution, refresh rate, colour space (sRGB/CMYK as my graphics card supported both) and nothing at all would stop the flickering pixels.Įventually in frustration I purchased a simple DVI to HDMI adaptor and combined with a 1.5m HDMI cable and appeared to fix the problem for me. When moving windows around they seemed to "push" the flickering pixels around which I found aggravating. Like you the problem was highly dependant on what was on screen and seemed more prevalent with darker images. I managed to find a solution to this not that long ago on a brand new monitor that required me to buy a cheap 5m DVI to HDMI cable (I couldn't get anything else quickly). TLDR: My fix was using a much shorter and better quality cable. I'm not even sure if it's hardware or software.Īny ideas? (windows 7 laptop connected to LCD by DVI to HDMI cable) I can't find any info on anything like this. It happens rarely enough that it's not a big deal, but it's such a strange problem it bugs me. It seems to occur randomly, other than that it seems to only occur in areas of pure black, and it's always pure 100% green. but it happens in a wide range of applications. My first thought was to blame a trolling blogger cunningly uploading an animated gif that simulates a failing pixel. ![]() It seems that everyphysical pixel is fine, but somehow something interprets part of the image in a way that causes flickering green. I scroll the page, and the green flickering pixels move with the image. There might be a couple of green flashing pixels in that black that shouldn't be there. The crazy part is, unlike dead/stuck pixels, they are relative to content on the screen and move with it.įor example, I might be looking at a web page with a picture that has lots of black. Occasionally, on my LCD screen, pixels that should be black flicker rapidly and constantly between black and green, about 4 flickers a second. ![]()
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