I've sent an email about this to RetroUSB support to see if they could explain what causes it, and also to request clearly labeled aspect ratios, which they said is in the works. I just wanted to know if this is happening to everyone, or just me, or if it's something someone can explain:

I've been enjoying the AVS a lot, but one thing that really bothers me is that the only pixel aspect setting which displays pixels evenly is the default setting. I've attached a close up picture of the AVS logo being displayed on my TV, on one of the non-default pixel aspect settings.



Basically, even though the portion of the AVS logo displayed is only supposed to be one pixel in width, diagonally, each of the pixels displays at a varying width creating an odd accordion effect. On the standard pixel aspect setting, pixels are displayed evenly at 6 bars wide, but in every other pixel aspect setting, they are displayed in various patterns of width. Here you have 4-5-6 4-5-4 6-5-4 repeating. I was hoping for a setting that would display them all at 5 bars wide, say, or 4.

Is this happening to anyone else with the AVS? Is it just me? Is this a concern for anyone else?

For the record, this is not a condemnation of the AVS, it's a wonderful piece of hardware, and I like it a lot. This isn't a deal breaker, I just want to know if this is supposed to be standard performance.

If that angle isn't set at 45°, could it be the off setting of the line due to it's angle?

Could you elaborate on what you mean? I have no idea what it is so I'm happy to try anything if anyone has any ideas about whether it's my TV or anything. I have another HD TV in the house that I could try hooking it up to, actually.

Edit: If you mean the angle of the picture taken, it should be nearly dead on, and the uneven pixel displaying is obvious at all viewing angles of the TV.

Sure! Even though it could be a HDTV stretch problem, it could also just very well be the angle to which the line is drawn. Example:



 
The line in the middle shows some mixed-matched pixels due to the angle of it. You can easily replicate this in MSPaint by selecting the line tool and looking at the pixels it draws in different angles.

I can't say this is the reason for certain, mainly because I don't have a 1:1 pixel screenshot of the AVS title screen logo. (If anyone has one, let me know!)

Now, if this is somehow happening to the games, then we probably can rule out the angles on which the lines are drawn as it could be something else. 
 

Oh, now I see what you mean! Yes, I think the angle on the AVS logo is meant to be exactly 45 degrees. Here is a shot of it at the default pixel aspect setting for some confirmation.



Here are also a couple pictures of the mountain in the background at the beginning of Super Mario Bros., which is of course a 45 degree line, for comparison:

Default:


1 notch below default:


This effect occurs on every setting but default, which I presume is 4:3. As the console supports 5:3 and 3:3 apparently, I thought maybe there would be a place on the slider where I would find another even display of pixels, but every notch on the slider aside from slap-bang in the middle produces uneven pixel output on my TV.

Edit: Actually upon another inspection I believe the default setting maybe closer to 5:3, as it's quite a bit wider than the image output by my Dreamcast at 4:3 when switching between the two video sources.

Yeah, then it's the ratio setting that, when displayed on your TV, sets each pixel to some strange bilinear setting just to fit within that screen's resolution. I think it's "filling in" extra uneven spots just to fit everything in correctly.

I think you're most likely right, but what concerns and confuses me is that none of the settings besides the default produce even pixel output, but when hooking my laptop via HDMI to my TV and setting an aspect ratio that is a multiple of 720p in FCEUX, pixel output is even. I anticipated that since AVS outputs at 720p, it should be able to do multiples of 720p without this uneven output, but that doesn't seem to be the case, though like you say, somehow it's probably related to my TV's handling of its output.

I think if it were a case of the line (pixel art) being drawn such that the border was "uneven" (i.e. not exactly 45 deg) then you couldn't possibly end up with 1-pixel-differences at 1080p or 720p, since your minimum pixel-difference on the system is 1 pixel at "240p" to start with.

So a one pixel difference at 240p becomes a 3-pixel-difference at 720p, and something else at 1080p, where the scaling math at that conversion is probably at the discretion of the TV manufacturer.


So I suspect the original image is a "perfect 45 deg" line.

Leaving it EITHER be a case of how the upconversion math was done on the AVS, OR (possibly more likely), a nuance of how the TV scaled from 720p to 1080p, since that isn't integer-math.
 

Is your TV 720p or 1080p?

Your laptop is going to generate native 1080p output via HDMI (so the emulator on-screen of the laptop is WYSIWYG) versus a 720p signal getting up-converted on the TV.

I doubt every TV manufacturer does exactly the same math to convert those signals, since they may have other approximations they do or corrections that are brand-specific.

 

I think this is probably it, and the question that I'm considering is, how can I avoid this issue? Currently my options for even pixel output are the stretched 5:3-ish looking default, or to set it to that and then have my TV squish that image to 4:3, which produces something more like a perfect square, which also isn't ideal.

Do they even make 720p to 1080p outside upscaler boxes that would do the upscaling for my TV to fix this? It's not a dealbreaker, as the AVS is still a fine piece of kit, but it's quite annoying.

I don't recall the exact discussion/thread, but I could have sworn that 5:3 was actually selected as the default, possibly for the issues you're running into.
(but it also had to do with "no true spec" for the exact "shape" of pixels on CRT televisions, so "4:3" is not necessarily an accurate shape on a pixel-size basis)

 

Yes I read some about using a Framemeister before I was introduced to the AVS and decided to plunge on it as it was cheaper (and cooler and fancier and less heretical than modifying my NES to output RGB), and I recall there was great debate about the "correct" output of pixel shapes, and some were saying even 4:3 is not accurate but more like 1.17:1 or something crazy like that.

I don't really care that much and usually just accept 4:3 as "good enough", but 5:3 is far too wide for my taste. I suspect I can probably just get used to it, but all my games look so... fat.
 
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Also, about this, I think I actually have my laptop outputting at 900p to the TV because I needed everything to be a bit larger to see from where I sit. Maybe if I have time later I'll change it to 720p output, run the emulator in full-screen at various aspect ratios and see what happens. If it produces the same output as the AVS, obviously that's the answer.

Edit: I didn't mean to double post, whoops.

Just to update some further experimentation, interestingly enough, setting FCEUX to output at 720p and then connecting to the TV via HDMI didn't reproduce uneven pixel output, when at 3:3, 4:3, or 5:3.

On the other hand, setting FCEUX to 4:3 produces an image comparable in width to the AVS default setting, so I suppose it is 4:3 after all, it just seems unusually wide.

Settings:


4:3


5:3


So, I'm quite baffled, as the output is perfectly even from FCEUX. Might it have something to do with the specific signal being output by the AVS?

Nevermind, I think I'm stupid and my entire problem has been solved by more careful comparison of FCEUX to the AVS output, and playing with the settings more.

I believe the pixel aspect slider of the AVS is actually moving from 3:3 to 5:3, with 4:3 being the default that's smack in the middle.

I think NOW I've identified what is a byproduct of upscaling to meet 1080p. Here are images of each of the 3 main aspect ratio settings available on the AVS, with the bar at 0, half, and full.

3:3 - As you can see, it's not perfect but it's a valiant effort at providing square pixels, varying in width between 4 and 5 bars a piece. I think this is a result of the upscaling.


4:3 - A perfect 6 bars in width on every pixel.


5:3 - Valiant but imperfect as with 3:3, here we're alternating between 6 and 7 bars a pixel.


None of this is so drastic and ugly as the inbetween settings, and now I feel much more at ease with the problem being identified.

Wow, it's like what's his butt was reincarnated. Wish I could remember his name.
I don't have an AVS, have no real use in it with my complex setups, but still want one.

When dealing with TVs, I like to think of logical and physical pixels. In this case, you have the physical pixels of your most likely 1920x1080 pixel screen. Everything must be stretched to this.
For logical pixels, you have the logical pixels the TV has, which if the AVS is outputting 1080p should match the AVS, and you have the internal nes logical pixels, 256x240. 1920/256 is 7.5 so the math there is a bit off. Part of that is because the nes kinda doesn't use 256 for the res, it's more of a 280 res, where you can only edit 256 pixels in the middle. And not even dead center in the middle. 1920/280 gives about 6.85, so you can see where matching up the signal is a pain.

Part of the issue, like I said, is the nes puts out 280 for the signal, but some of that is border\filler, only the 256 pixels are usable. And even then they have junk on the edge. And back in the day, TVs varied in aspect ratios. A LOT. Many TVs had over scann issues. But now we have nice, digital panels, with "hard coded" 1920x1080 panels, so there should be no overscan issues, right?

Wrong. TVs still have overscan problems. When you see a bunch of TVs playing in walmart, TV makers know if they put a bit of overscan on their TV, it'll make the picture bigger. If you watch a news cast on there, you'll generally be fooled into thinking the one with the announcer looking bigger would be the better TV. My plasma from 2004, while I loved it dearly, has overscan issues, 3%. My CRT has about 12%, I can't see life bars in Zelda 2. This overscan issue will also mess with pixel ratios like you're seeing, so you might want to check into that too.

AVS outputs 720p and relies on the TV to upscale from 720p to 1080p.
 

While I think that everyone's general idea is on point, I am curious as to why setting my laptop and FCEUX to the same resolution doesn't produce the same uneven ouput.

But that being said, I've decided I'm happy enough to just leave the AVS on 4:3 and not worry about uneven pixels (they're still slightly uneven vertically but it's hard to notice), especially since it handles input lag and vsync so much better than any emulators I've tried. I'm happy with it, overall, and think it's a preferable substitute for emulators.

There's a difference between your TV's pixels and the NES' pixels. These days they are both digital and there is no such thing as a non-square pixel. If your setting is not an exact integer multiple, then some will be wider than others BY NECESSITY. The correct aspect ratio to match the analog non-square pixels isn't even possible with integer scaling on standard HDTV native resolutions. That's just the nature of what you're asking for with displaying 240p on modern TVs. You couldn't scale it exactly on graph paper either.

Additionally, many TVs will process the image and cause similar artifacts even if scaling were perfect.

PCs have the same problem. It's why so many emulators have incorrect aspect ratios and screenshots are often not as wide as the stretched window. Analog VGA monitors and such can have non-square pixels and run games at a perfect multiple of their native resolution, but that hasn't been possible for standard PC monitors in a very long time. On the other hand, PCs generally have higher resolutions and have more native pixels to work with when doing the scaling so that they can be closer, but a 1080p PC monitor and a 1080p LCD will have the same problem with scaled 240p content.

If the AVS and Hi-Def NES supported 4K output then they'd have more pixels for the scaling to work with and it would be less noticeable. We're trying to fit a square peg in a non-square hole (or is it the other way around?).

Right, and I understand all that, but my question is, if I hook my laptop, running FCEUX, to the same TV the AVS is hooked up to and set it to 5:3 or 3:3 it produces pixels of even 8 pixel width or 4, respectively, while rendering at 720p output to the TV.

However when the 720p output from the AVS is processed by the TV, it creates alternating patterns of 4/5 and 7/8.

Those pixel widths are evenly divisible of 1920 and should be possible to display evenly as FCEUX does but the AVS output doesn't, but the outputs should be basically the same, right?

Displaying them "evenly" means displaying the entire image either squashed or stretched so that the collective aspect ratio will be wrong. It's either/or. I don't have an AVS but, if it is anything like the Hi-Def NES in that regard, then it has options to do integer scaling too. If the TV is screwing up the pixel shapes even when the AVS is outputting them with integer scales, well, it wouldn't be the only TV in the world to do that. A connected PC could be at a different refresh rate causing the TV to treat it differently (automatically full pixel/no overscan, for example).

If you can find an option to set the input to full pixel or 1:1 or no overscan, chose that and see if it helps.

Hi Lifeinsteps. Let me explain what's going on between your AVS and the HDTV. The AVS outputs a picture at 1280x720p. You have correctly concluded the AVS can only do integer scaling (or nearest neighbor). So NES native 256x240 pixels divides evenly into 1280x720 pixels an even 5x3 times, so 720p is ideally suited for upscaling the NES screen. Well 5x3 is a bit wide and doesn't look right, so we have 3x3 and 4x3 options to make the border skinnier.

Additionally, there is a scanline option that dims every third scanline, and depending on how good the scaler is on your HDTV display, can be the bee's knees or look like pants. An "ideal" display will be 1080p native with zero overscan. The result is that the display interpolates the pixel data by upscaling from 720p to 1080p, locking a 2:3 ratio. This means that NES scanline becomes 3 rows at 720p and 4.5 rows at 1080p. This creates a very clean look, especially with quality bilinear filtering.

Old mockups (4x3 mode 50% scanline intensity):
720p: http://sta.sh/02bb7cc9dt06...
1080p: http://sta.sh/03asg71xf25...

The best display to use for AVS, IMO, is a 1080p PC monitor, with audio bypass. PC monitors are designed for interaction (ultra low latency) never overscan, accept a wide range of resolutions and refresh rates, and have very little lag inducing post processing. I use a 1080p ASUS monitor for HD gaming. Another user posted in a thread that he used an ASUS and his display looked almost identical to my mockups.

What you see with your 1080p HDTV appears to be native 1.5x scaling. At 3x, NES pixels will be 4.5 pixels wide. At 4x, NES pixels will be 6 TV pixels wide, and at 5x, NES pixels will be 7.5 pixels wide. Squishing to 4:3 aspect will result in pixels that are 5.75 pixels wide.

Now some displays may not be 1080p native, or have overscan to various degrees. Oftentimes the OEM TV menu provides little to no adjustments for these issues. In the past, "720p" sets were available which only supported 720p or 1080i resolutions. These TVs were actually 1366x768 native and most such sets included overscan built in. The 2006 Sanyo in my living room is one example. I imagine AVS scanlines will look bad on it because each line will have varying amounts of overlap with adjacent lines in a non-uniform manner creating a varying width and intensity effect, but IDK as I have not recieved mine yet. Similar uneven issues may result from odd resolutions, 900p, 1080p native with overscan, etc, though I imagine a 1440p or 2160p (4k) widescreen monitor would be another "best" case. I would be leery of 4k HDTVs unless they are confirmed good on displaylag.com Also avoid anything advertised as "120Hz."

Hope this helps. HDTVs vary greatly even within brands, so do your homework before buying...
  Nope, I am still here. Now that NA mods have conveniently grouped all of the AVS related threads together, they are easier to find!  
 

The reasons TVs still simulate overscan is because some local broadcasts have garbage around the edges of the screen. Also, throwing out the edges gives the image processor some room to work with.
 

I find mine a bit more likely honestly, otherwise it would most likely be adjustable and set standard in the factory.