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General => Tech, Science, IT discussion & News => Topic started by: gameblabla on April 09, 2017, 06:14:49 PM

Title: 960i possible on the Gamecube/Wii ?
Post by: gameblabla on April 09, 2017, 06:14:49 PM
A year ago, the Dolphin team had announced that they even support 960i as an internal resolution, though they mentioned that
only a few homebrew supports it.
https://dolphin-emu.org/blog/2016/02/02/dolphin-progress-report-january-2016/ (https://dolphin-emu.org/blog/2016/02/02/dolphin-progress-report-january-2016/)

It went almost unnoticed until someone on reddit asked the question if this was actually true, since
it was known that the highest resolution possible on the GC/Wii is 576p on a PAL console.
960i would be 480p (640x480p) but with double the vertical resolution (640x960).

https://www.reddit.com/r/emulation/comments/43ttef/dolphin_progress_report_january_2016/ (https://www.reddit.com/r/emulation/comments/43ttef/dolphin_progress_report_january_2016/)

Anyway,  one developer called Extrems (who also worked on Not64) told JMC47 that yes, 960i is possible
but without mentioning which homebrew actually makes use of that resolution.

Then pĥire chimed in and said that triggering this mode is simple :
Use the 480p, and then "increase the vertical blank timing for each field by half a line".

A similar trick is actually used by official games (VC emulation) for 240p on the Wii :
it uses the 480i mode and they remove half-line offset.

But so far, no one has demonstrated the use of that mode.... not even a simple demo.
According to phire, such a mode would have a resolution of 720x960.
He even goes as far as saying that 720p (1164x720) is theoretically possible on the Wii,
although only at a refresh rate of 24hz. (12 frames per second)

Maybe @Streetwalrus has an idea, since he's interested in Gamecube stuff.
It would be very cool to be able to make use of 720x960 or even the theorical 720p low-refresh rate video mode !
Imagine high-def Visual Novel on it !
Your thoughts .
Title: Re: 960i possible on the Gamecube/Wii ?
Post by: novenary on April 09, 2017, 06:47:55 PM
Yes it's possible, Extrems has 720x960i and 1440x480i working on real hardware. It's non standard as hell though, and only works with a capture card or probably a CRT.

Also, for 240p, that's exactly what consoles have been doing since the dawn of times.
Title: Re: 960i possible on the Gamecube/Wii ?
Post by: gameblabla on April 10, 2017, 12:24:46 AM
Quote from: Streetwalrus on April 09, 2017, 06:47:55 PM
Yes it's possible, Extrems has 720x960i and 1440x480i working on real hardware. It's non standard as hell though, and only works with a capture card or probably a CRT.
Also, for 240p, that's exactly what consoles have been doing since the dawn of times.
Yeah, that's what i thought. Most retro gamers these days use their consoles over a framemeister or OSSC, though.
He said that 960i should work fine on a CRT that supports 480p. (but i'm not sure it will look that great, unless you use a PVM)

Has he released some code for 960i ? Could not find any sadly ;(
Title: Re: 960i possible on the Gamecube/Wii ?
Post by: novenary on April 10, 2017, 12:27:23 AM
It's in Swiss.

Also c the framecter. :P
Title: Re: 960i possible on the Gamecube/Wii ?
Post by: gameblabla on April 10, 2017, 06:44:40 PM
Quote from: Streetwalrus on April 10, 2017, 12:27:23 AM
It's in Swiss.
omg... you're right. There's even support for 1152i (720x1152, if i'm correct) goddammit !
Granted, that makes the game even less horizontal-hish but the TV/capture card can stretch the image if needed.
That is, unless you actually intend to play a shmup then this resolution is perfect lol.

I saw someone even suggested to the Nintendont team to add an option to force 960i/1152i to games,
similar to the option to force progressive scan on GC games.
The whole thing reminds how some PS2 games can be hacked to work at 1080i.
I wonder if the same is possible for GC games as well...
Title: Re: 960i possible on the Gamecube/Wii ?
Post by: aetios on April 10, 2017, 07:09:18 PM
That would be really cool, I'd like to try that :D
Title: Re: 960i possible on the Gamecube/Wii ?
Post by: Dream of Omnimaga on April 10, 2017, 07:12:21 PM
I would be definitively interested in seeing how some of the GC games, especially Zelda Twilight Princess and Windwaker, look like in 960i.
Title: Re: 960i possible on the Gamecube/Wii ?
Post by: novenary on April 10, 2017, 07:14:48 PM
These modes only affect the way the video controller outputs the signal, in official games it won't do much besides upscaling, but homebrew can take advantage of it more fully.
Title: Re: 960i possible on the Gamecube/Wii ?
Post by: gameblabla on April 10, 2017, 07:19:03 PM
Quote from: Streetwalrus on April 10, 2017, 07:14:48 PM
These modes only affect the way the video controller outputs the signal, in official games it won't do much besides upscaling, but homebrew can take advantage of it more fully.
So we would need to hack the official games as well to tell it to render it to a higher resolution as well ?
Or it's a little more tricky than that and can't be easily done ?

As for PAL Wiis, can we force games to force rendering to 576p instead ?
It's only slightly higher than 480p (640x480 versus 720x576p) but any increase in details is welcome on an original console.
Title: Re: 960i possible on the Gamecube/Wii ?
Post by: novenary on April 10, 2017, 07:33:23 PM
You can force any mode, but usually games just render a taller image, and then you're stuck at 50hz which is horrible because most games use framerate for timing.
Title: Re: 960i possible on the Gamecube/Wii ?
Post by: Dream of Omnimaga on April 10, 2017, 08:19:58 PM
Quote from: Streetwalrus on April 10, 2017, 07:14:48 PM
These modes only affect the way the video controller outputs the signal, in official games it won't do much besides upscaling, but homebrew can take advantage of it more fully.
Ah ok then. Still nice to know it's possible, though.
Title: Re: 960i possible on the Gamecube/Wii ?
Post by: JosJuice on April 11, 2017, 09:50:27 AM
Quote from: gameblabla on April 10, 2017, 07:19:03 PM
So we would need to hack the official games as well to tell it to render it to a higher resolution as well ?
Or it's a little more tricky than that and can't be easily done ?
It's trickier than that, because the GPU's internal framebuffer isn't big enough to handle those kinds of resolutions.
Title: Re: 960i possible on the Gamecube/Wii ?
Post by: novenary on April 11, 2017, 10:03:31 AM
Yeah, that's the other problem. But you can use the scissor box to render slices of the image and then put them together in software. As long as you only slice vertically, it's pretty inexpensive to do.

Also:
Quote from: #gc-forever23:15 <Extrems> Streetwal: The 960i patch in Swiss doesn't affect the video output yet, it's forcing field rendering for 960i resolution in 60 FPS games.
23:17 <Extrems> I've committed the preliminary timings from back then to libogc-rice.
23:23 <Extrems> They still seem weird to me, but looking at early HDTV specifications, 1152i seem ok?
23:24 <Extrems> I still have no idea if they work properly on a CRT.
23:24 <Extrems> And some halflines are corrupt.
Title: Re: 960i possible on the Gamecube/Wii ?
Post by: Dream of Omnimaga on April 11, 2017, 06:44:05 PM
There's also the issue that even if 960i is achieved on the user's end, he still needs to mod his Gamecube with HDMI support, right?
Title: Re: 960i possible on the Gamecube/Wii ?
Post by: novenary on April 11, 2017, 06:53:28 PM
Currently this has only been tested with the component cable which costs an arm and a leg, as for HDMI requiring mods, something's coming. Also remember that you need to mod the console to run homebrew, or use one of those Datel boot discs.