[Feature request] Aspect ratio options

[Shady Guy Jose]

So, I've noticed that the "Force 4:3" option doesn't really force 4:3. It forces a weird aspect ratio that's closer to 6:5 than 4:3 (it renders as 1748×1440 on my phone). After some digging, I found out that this matches the square-pixel aspect ratio of the GameCube (640×528 internal resolution — 40:33). However, most games I play are optimized for 4:3 stretching on SD CRT TVs, so circles show up as vertical ellipses. Is it somehow possible to rename this aspect ratio option as "Original", "Pixel-perfect", or something, and add an actual 4:3 option? Most NES/SNES emulators can do this, since those consoles output 8:7 (256×224) internally, which is then stretched to 10:7 (4:3 — 320×240 — with 8-pixel tall black bars on the top and bottom). From what I can see, this actually applies to the Windows version as well, but I mostly play on Android, so I'm posting this here. I'd just like to see my games as they originally looked.

[MayImilae]

GameCube and Wii games are never exactly 4:3, they are always slightly off. This is just a side effect of supporting CRTs, they just didn't need to care as CRT's overscan would cut a lot of it out anyway. In this past we stretched the output to match 4:3 or 16:9, that is where you saw those ovals. But today, in Dolphin by default we show all the pixels the consoles render without distortion, regardless of the aspect ratio. This leads to small black bars but a distortion free image. However you can turn on Crop to fill the entire 4:3 and 16:9 canvas without distortion, but at the cost of losing some pixels the game is rendering. But that's fine as that more or less recreates overscan, which the game devs designed around. We avoid stretching as much as we can, hence the force 4:3 option not stretching it to 4:3 - you still need Crop to be enabled for it to fill the 4:3 frame completely. And we're not about to add stretching back, it's awful.

As for Android, Crop should be there as well. So that should give you want you want by enabling it.

After some digging, I found out that this matches the square-pixel aspect ratio of the GameCube (640×528 internal resolution — 40:33).

That is incorrect. Few games rendered in the full resolution available to them, the higher pixel size was more for better region compatibility than anything. It makes sense if you think about it - what game dev (making an NTSC version) would waste GPU resources they could invest elsewhere into rendering a bunch of pixels no one (in NTSC) would see? So the NTSC version would render in 640x480ish and not use the whole framebuffer. For PAL it is a bit more complicated but I'll just leave it at that.

[Shady Guy Jose]

GameCube and Wii games are never exactly 4:3, they are always slightly off. This is just a side effect of supporting CRTs, they just didn't need to care as CRT's overscan would cut a lot of it out anyway. In this past we stretched the output to match 4:3 or 16:9, that is where you saw those ovals. But today, in Dolphin by default we show all the pixels the consoles render regardless of the aspect ratio, so there will be some small black bars. However you can turn on Crop to force exactly 4:3 and 16:9 without stretching, more or less recreating the intended look of the game with overscan on a CRT. We do not allow stretching at all, hence the force 4:3 option not stretching it to 4:3 - you still need Crop to be enabled for it to fill the 4:3 frame completely. And we're not about to add stretching back, it's awful.

On Android, I believe it also has crop. So that should give you want you want by enabling it.


That is incorrect. Few games rendered in the full resolution available to them, the higher pixel size was more for better region compatibility than anything. It makes sense if you think about it - what game dev (making an NTSC version) would waste GPU resources they could invest elsewhere into rendering a bunch of pixels no one (in NTSC) would see? So the NTSC version would render in 640x480ish and not use the whole framebuffer. For PAL it is a bit more complicated but I'll just leave it at that.

I get what you mean, but the fact remains that I've tested 2 different games and the 4:3 option gives me ovals, not circles. And I actually took a ruler to measure it and the size matches the 40:33 aspect ratio of the 640×528 resolution. I'll attach the screenshots for reference. I'll play around with the crop option if it's present on Android, but it doesn't seem like a perfect solution, since I imagine that'll make me lose content.
   
   
The menu options in Sonic Adventure 2: Battle and the A button prompt's surrounding white circle in Medabots Infinity look like circles on my 4:3 CRT, but not here. I'm sure a lot of people would prefer this to 4:3 stretching, but would it be harmful to just have both options, as most NES/SNES emulators do?

[Shady Guy Jose]

GameCube and Wii games are never exactly 4:3, they are always slightly off. This is just a side effect of supporting CRTs, they just didn't need to care as CRT's overscan would cut a lot of it out anyway. In this past we stretched the output to match 4:3 or 16:9, that is where you saw those ovals. But today, in Dolphin by default we show all the pixels the consoles render without distortion, regardless of the aspect ratio. This leads to small black bars but a distortion free image. However you can turn on Crop to fill the entire 4:3 and 16:9 canvas without distortion, but at the cost of losing some pixels the game is rendering. But that's fine as that more or less recreates overscan, which the game devs designed around. We avoid stretching as much as we can, hence the force 4:3 option not stretching it to 4:3 - you still need Crop to be enabled for it to fill the 4:3 frame completely. And we're not about to add stretching back, it's awful.

As for Android, Crop should be there as well. So that should give you want you want by enabling it.


That is incorrect. Few games rendered in the full resolution available to them, the higher pixel size was more for better region compatibility than anything. It makes sense if you think about it - what game dev (making an NTSC version) would waste GPU resources they could invest elsewhere into rendering a bunch of pixels no one (in NTSC) would see? So the NTSC version would render in 640x480ish and not use the whole framebuffer. For PAL it is a bit more complicated but I'll just leave it at that.

Follow-up:
I have looked around for the crop option and I haven't found it on Android. I have also tested more games and it seems that circles are consistently squashed. Screenshot for reference:
[attachment=19659]

[Shady Guy Jose]

Sorry for triple posting, but I have further confirmation. I tried another game (Timesplitters 2), and that one actually renders at 640×480, and hence a perfect 4:3! So I guess the other 3 games I tried are actually rendering at 640×528. Is there really no way to stretch those to 4:3? Having the option wouldn't hurt anyone, I think...

[vlad54rus]

Indeed, Sonic Adventure 2 has squashed aspect ratio, but only in 60 Hz mode (NTSC and PAL60). PAL doesn't have such issue.

Spoiler:

[Shady Guy Jose]

GameCube and Wii games are never exactly 4:3, they are always slightly off. This is just a side effect of supporting CRTs, they just didn't need to care as CRT's overscan would cut a lot of it out anyway. In this past we stretched the output to match 4:3 or 16:9, that is where you saw those ovals. But today, in Dolphin by default we show all the pixels the consoles render without distortion, regardless of the aspect ratio. This leads to small black bars but a distortion free image. However you can turn on Crop to fill the entire 4:3 and 16:9 canvas without distortion, but at the cost of losing some pixels the game is rendering. But that's fine as that more or less recreates overscan, which the game devs designed around. We avoid stretching as much as we can, hence the force 4:3 option not stretching it to 4:3 - you still need Crop to be enabled for it to fill the 4:3 frame completely. And we're not about to add stretching back, it's awful.

As for Android, Crop should be there as well. So that should give you want you want by enabling it.


That is incorrect. Few games rendered in the full resolution available to them, the higher pixel size was more for better region compatibility than anything. It makes sense if you think about it - what game dev (making an NTSC version) would waste GPU resources they could invest elsewhere into rendering a bunch of pixels no one (in NTSC) would see? So the NTSC version would render in 640x480ish and not use the whole framebuffer. For PAL it is a bit more complicated but I'll just leave it at that.

@MayImilae have you had a chance to look at the replies? I believe we've provided enough evidence that some games are indeed distorted at native aspect ratio (at least if you can see the attachments — I can't on my desktop browser, but I can on mobile, for some reason). Cropping isn't available on Android, but it wouldn't solve the issue anyway. I get that stretching to 4:3 makes some games look bad, but some desperately need it to look the way they are supposed to (I have found at least 3 examples). There's already a "stretch to 16:9" option and a "stretch to screen" one. Would it really hurt to add a 4:3 one (keeping the current — native — one intact for people who prefer it, of course)?

[MayImilae]

Honestly I'm not convinced. We're following what the game is asking the console to output. If the UI has ovals there, it probably had ovals on console to. Whether that is deliberately trying to compensate for crappy screens that distort the image or just laziness on behalf of the developers when porting between regions, I can't say. Plus, just because a UI in one spot is squished doesn't mean -the game- is squished. The game may be fine and the dev just didn't care about it for the UI. There's a lot of possible answers here.

If you want to pursue this further, you'll need to back this up with console capture. Prove to us that this is a Dolphin issue and not a game issue.

[mbc07]

Follow-up:
I have looked around for the crop option and I haven't found it on Android.

Although not currently exposed in the Android GUI, you can still enable it. With a text editor of your preference, open Internal Storage => dolphin-emu => Config => GFX.ini and add Crop = True under the [Settings] section. To disable it, change to Crop = False or delete the line, then save the file again...

[Shady Guy Jose]

Honestly I'm not convinced. We're following what the game is asking the console to output. If the UI has ovals there, it probably had ovals on console to. Whether that is deliberately trying to compensate for crappy screens that distort the image or just laziness on behalf of the developers when porting between regions, I can't say. Plus, just because a UI in one spot is squished doesn't mean -the game- is squished. The game may be fine and the dev just didn't care about it for the UI. There's a lot of possible answers here.

If you want to pursue this further, you'll need to back this up with console capture. Prove to us that this is a Dolphin issue and not a game issue.

I don't have a capture card, but I do have a 4:3 camera, so I'll make do. Here's the best proof I can provide.
This picture shows 3 different scenarios:

1. Original game running on a GameCube at 480i on a CRT, photo downscaled to 640×480
   
2. Same ISO running in Dolphin. Downscaled to 480p with the aspect ratio preserved.
   
3. PC port running at a 4:3 resolution (1280×960), downscaled to 640×480
   

Now, you could argue that the differences I see are due to the slight overscan my CRT has, but, while present, it isn't relevant here. I ask that you please direct your attention to the copyright symbol in the lower left corner. Out of all three screenshots, Dolphin's is the only one that squishes it to a vertical oval. It looks like a small difference, but, while by no means game-breaking, it's noticeable in gameplay. And, as shown, it does not occur in original hardware. I hope you find this evidence satisfactory.

   
Picture link in case the attachment doesn't show up in your browser

I believe I can explain why this is the case. In the age of CRTs, as you probably know, signals had no declared/discrete horizontal resolution, so each line would always be stretched to the full width of a 4:3 panel. This meant that devs could get away with using resolutions that were slightly off, as long as they compensated for it in actual rendering (which they did very often in the SNES days, for example). What I'm asking for is the option to replicate this CRT stretching to 4:3 in Dolphin, in the same way we already can for 16:9.

However! All this talk of cropping has also reminded me of one thing. In order to perfectly replicate the original picture, aside from stretching, it may be necessary to crop a few lines from the top/bottom in games that render more than 480 of those. This is hard to tell because of overscan (we never know which lines are thown away entirely and which are lost to overscan), so it would require testing, which I'd be happy to do and get back to you if the stretching option ever does get added.