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Discussion Starter · #1 ·
When watching the Blu-ray of The Dark Knight on my PC with MPC HC, I noticed curved moiré patterns appear on some buildings intermittently on a panning shot from 00:31:58 when using a refresh rate of either 23 or 24 Hz; there is no issue when using 60 Hz. I've tested this on MPC HC, using MPC HC's internal video decoder and the EVR (cust pres) renderer, on two different PCs; one using an ATI 3650, CCC v10.1, and the other an ATI 5770, CCC v10.10. Given that the movie's native refresh rate is 23.976 fps, wouldn't playback at 23 Hz eliminate such issues?


I have both PCs connected to a Samsung LE46C530 LCD TV directly via HDMI. The computers' resolution matches that of the TV, 1920 x 1080, and I've selected "Screen Fit" so that there is no overscan. I have not turned on any post processing options in CCC, e.g. edge-enhancement, de-noise etc.


I would appreciate any help with this; hopefully there's something small I'm missing.
 

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moiré is not a framerate issue. Is it visible when you pause? Or perhaps it's not moiré what you mean. Can you capture it on a picture (moiré can be captured this way most of the time), or if when you pause it shows, can you take a screenshot?
 

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Discussion Starter · #4 ·
Thanks for the reply Andy o. I thought it was a moiré issue, hence the title, but I guess it mustn't be after all. When paused, the issue doesn't appear, so I can't take a screenshot.


The reason I thought it was a moiré issue is because it looks very similar to the example of incorrect deinterlacing in this link towards the bottom of the page; I didn't think moiré was exclusive to deinterlacing issues. Given that the issue I'm experiencing seems to only occur on objects with lots of straight lines, i.e. the rows of windows on the buildings, moiré seemed to fit.


Do you have any idea what the issue could be if it's not moiré?
 

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Moiré is a byproduct of (usually) digital resolution, so it could be an issue with interlaced content, but it's not exclusive to deinterlacing issues, which is what that link is about. It can be visible in progressive video, and even on digital photos. But it is visible also when you pause.


Your source is 1080p, so it's not the same issue as on that link anyway. I don't know what it could be, but it's most likely some kind of motion artifact, less likely a decoding issue. Can you post a screenshot of that scene anyway, in full resolution?
 

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Discussion Starter · #6 ·
No problem; see below.




Additionally, when you click on the thumbnail above and are brought to the Imageshack wesbite, you can see the issue I'm referring to, coincidentally, on the smaller version of the image before you click to view the image in its original size; the white building towards the middle left of the image is where the issue is most pronounced.
 

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Yeah, the smaller pic shows moire all right, this is due to poor resampling usually, or poor anti-aliasing. But it shouldn't be different with 24p and 60p, that's weird. Especially if the full-size source picture doesn't have it.
 

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Discussion Starter · #8 ·
As I mentioned, it seems coincidental that the thumbnail on the Imageshack website shows the same issue I'm witnessing when watching that particular scene in the movie, but at least it gives you a good indication as to what I'm seeing.


I really don't know how this issue could be occurring, especially on two different computers, with two different GPUs and, which I didn't mention before, two different Oses; the 3650 GPU is used with Vista while the 5770 GPU is used with Windows 7. The only commonality between the two computers is the display, but I very much doubt that it is at fault; though I can't completely rule it out without further evidence.


There's definitely something going on here, but as to what, I haven't a clue.
 

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I can see it happening if the content is interlaced, as in the link you provided.


Another possibility is that your display is scaling differently for different refresh rates. Are you sure it's doing 1:1 pixel mapping on both 24p and 60p inputs? Mine has separate options for different input resolutions and refresh rates. Also, make sure the overscan option is set at 0% on the ATI CCC, both for 59/60 Hz and 23/24Hz output. Set it for one, change refresh rate, and look if it's still at 0%. If not, that was probably your problem


Also I just did a quick google at your display. It's a UK 50 Hz model, right? I don't think it does multiple of 24 Hz refresh or 60 Hz, does it?
 

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Discussion Starter · #10 ·

Quote:
Originally Posted by Andy o /forum/post/19654445


I can see it happening if the content is interlaced, as in the link you provided.


Another possibility is that your display is scaling differently for different refresh rates. Are you sure it's doing 1:1 pixel mapping on both 24p and 60p inputs? Mine has separate options for different input resolutions and refresh rates. Also, make sure the overscan option is set at 0% on the ATI CCC, both for 59/60 Hz and 23/24Hz output. Set it for one, change refresh rate, and look if it's still at 0%. If not, that was probably your problem


Also I just did a quick google at your display. It's a UK 50 Hz model, right? I don't think it does multiple of 24 Hz refresh or 60 Hz, does it?

I just checked it there and the "Screen Fit" option is still selected when the resolution is set to 24 Hz. I know the TV doesn't have a multiple of 24 Hz refresh rate, like the 72 Hz found on Pioneer plasmas, but from the reviews I've read, especially this one, it does display 24 Hz content without telecine judder, as stated in the "Benchmark Test Results" section in the aforementioned link, which would indicate that it is displaying 23.976 fps content accuaretly and correctly; as far as I can tell from all the information available.
 
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