Gamecube Digital AV to direct HDMI / VGA mod...

[OzOnE]

It's a cheap board from China with an EP2C8Q208 (Cyc II). A bit like this one, but with ~8'000 logic elements and a FT245 USB FIFO...
http://www.ebay.co.uk/itm/Altera-Cyclon ... 25754d6042

(can't find my exact board atm?)

The design is fairly small though, and even with the SDRAM scan doubler it only needs around 45% of the EP2C8.

I still have the "new" US GC sitting here, and I've already installed the first Xeno chip into the PAL one, but I just have SO many other projects on the go at the same time.

I'm intending to work on this again soon, but need to sort out these other projects first (such as the DC IDE adapter).

I think the YCbCr stream is very close to the bt.601 / bt.656.
Well, I suppose the timings for interlaced modes are basically the same, it just needs the SAV / EAV flags to be injected?

As for the code itself, I simply used the info on gamesx and the GC patent to extract the YCbCr and "Flags" bytes.
The info in this post gives quite a lot to go on, but please let me know if you need further info...
viewtopic.php?p=18052#p18052

And here's the patent (pages 21 and 22 for the vid protocol)...
http://www.google.com/patents?id=Rk0NAA ... &q&f=false

I can't really post the full code atm, but don't mind giving help / suggestions.

The protocol simply gives the vert / horiz / blanking / burst signals directly, but the DAC itself must be adding the actual colour bursts.

I only know Verilog tbh (and still learning at that).
I can mostly read VHDL, but it's very ugly / verbose and I've never quite understood it's appeal.

If I find a chunk of VHDL I want to understand, I generally convert it to Verilog first (with X-HDL or Veritak).

OzOnE.

[Ashen]

OK I have added the extra two signals to the connector on the next pcb as well as a jumper for selecting GC mode (note this only provides the possibilty, the actual functionality doesn't exist)

http://forums.benheck.com/viewtopic.php ... &start=105

Lets keep our fingers crossed.

[MockyLock]

I'm following this thread since a long time now.
I cross my fingers too

[theclaw]

Me too. Someday no more DAC, let's harness that elusive YCbCr.

[tesla246]

OK I have added the extra two signals to the connector on the next pcb as well as a jumper for selecting GC mode (note this only provides the possibilty, the actual functionality doesn't exist)

http://forums.benheck.com/viewtopic.php ... &start=105

Lets keep our fingers crossed.

wow you are amazing marshallh! Some nice progress. I'd buy such an adapter in a heartbeat. Crosing my fingers I will able to buy one of those

[ShortFuse]

Hi!

I'm posting on behalf of the Melee competitive community. We are all currently using composite or SVideos connected to old CRTs at tournaments. The reason we do this is because CRTs have less latency than LCDs and going through the conversion process of DAC, deinterlacing and upscaling onto LCDs causes too much latency for competitive play.

This means we are always stuck on 480i at tournaments. I have a component cable and use it personally with a RGsB (Analog Component) to RGBHV (VGA) transcoder and have used it with a CRT monitor. It works great and I couldn't care less about the 15khz intro not displaying.

To be honest, we have a problem. CRTs are getting harder and harder to find. Also, they're extremely bulky and the computer monitors that display 480p are extremely heavy.. The fighting game community (Street Fighter 4, Persona4, KoF) has moved to LCDs because the PS3 natively outputs over HDMI.

We can't.

I'm wondering if you are interested in selling a transcode only, no deinterlacing HDMI/DVI-D cable for the GameCube. If it does include deinterlacing, I hope it doesn't affect 480p in any way.

We are a very large community as you might have seen at EVO2013 and you definitely will have support.

If you need anything at all, like cubes, cables, or games, let me know and I'm sure I can arrange it to be shipped free of charge. I just got myself a fully unmodded Panasonic Q with native Toslink out and even though it's hard for me to say it, I can part with it if it helps you achieve true digital out for the GameCube.

Thanks!

[BenoitRen]

Wouldn't it be easier to use Wii consoles with a VGA cable instead?

[pr0ton]

Wouldn't it be easier to use Wii consoles with a VGA cable instead?

How?
(OzOne still around btw?)

[OzOnE]

Hi, @ShortFuse,

I've just had a quick look at some tournaments on YouTube.
I can understand the need for decent digital output from these older consoles, especially since the official component cable costs a ridiculous amount.

Firstly - hang on to your Panasonic Q!!
It's not needed at all for work on the HDMI project, so keep hold of it. Don't even think about it!

I'll try to do what I can to get into this project again, but I'm always busy with other projects.
Most of these are retro computer related though, so the HDMI thing is something I still want to work on.

I do have the US GC now, and have added the Xeno chip to the PAL one.
But, I've yet to burn a disk which actually boots on the damned thing. lol

I'm sure the chip is installed correctly, as it boots into the menu when the various buttons are held down.

As for the HDMI project, I've just changed the scandoubler code from the hugely over-complex SDRAM version to a much simpler one.
This is likely similar to what Marshall was initially using on his first VGA board for the N64.
I sent the GC code to Marshall a few months ago, but he is also very busy with other projects etc.

(To be fair, the actual code which extracts the video and sync from the Digital port was the easy part, so sending the code to Marshall was merely an incentive to him to add GC support to his board. )

The scandoubler is what presents the biggest headaches, but also getting a custom PCB designed is not one of my strongest skills.
Although, I recently designed a board for a project and sent off to China for 20 PCB's. It just takes ages to finalize the design.

So, I'm hoping to try getting a 480p game booting on the PAL GC (the one with the Digital port soldered) and also see how the simple scandoubler works with 480i / 576i games.

The latency thing is interesting, because it's closely related to work being done on the Oculus Rift (finally have mine now)...

The Realtek scaler chip used on the Rift is quite common on those cheap controller boards / TFT kits from China.
There is very little latency in the scaler because it only needs to buffer a couple of lines and essentially does the scaling on-the-fly.

I've heard that some models of PC LCD monitor use similar chips, and so also have very low latency.
I'm not sure which monitors these were now, but maybe this is an option for you?

The simple scandoubler on the FPGA also only buffers one video line at a time, then simply displays it twice (with an extra Hsync pulse added).
So, as long as you can find an LCD with low latency, the lag should be virtually imperceptible. (CRT is still the Gold Standard ofc).

I'll see what I can do.

OzOnE.

[ShortFuse]

Thanks for responding!

I actually have a fully working US cube with a Viper GC installed and a few burned discs just sitting at home unused. Now that I have a Q and freeloader disc, I have less use for a third cube. (I have an unmodded one I take to tournaments).

I can sent it over if it helps.

As for the latency points, I'm assuming the line doubler will be inactive when a 480p signal is outputted. Or is the line doubler not related to deinterlacing?

Also, as for scaling, the XRGB+ which uses a Marvel Qdeo chip up scales from 480p to 1080p with about 2ms of latency. Being that the Qdeo has heavy processing, the Realtek shouldn't be any slower, I assume.

The act of frame buffering scares me a bit due to the fact that 16ms (1frame) is about the upper limit of latency before people start complaining. EVO used one specific monitor for all the games and it was the Asus VH236H at 8.3ms latency with HDMI in. Sometimes the Realtek scaling will be faster than the monitor and then sometimes it won't so maybe a hardware switch would could be useful.

As for using an LCD now, the difficulty is finding the required component cable to output at 480p, skipping deinterlace lag. Also, LCDs will take the analog YPbPr converter by the MX chip and reconvert it right back to digital RGB. The GameCube component cable was really meant for analog CRT sets with 480p and 1080i, not digital LCDs.

Thanks again! Let me know of you need anything at all!

[emu_kidid]

2ms latency monitors aren't that expensive these days

[ShortFuse]

2ms latency monitors aren't that expensive these days

2ms is just pixel response latency which helps eliminate ghosting. It's not the same as input lag. It's just a component, not the whole thing.

Also you have account for deinterlacing, scaling and DAC. Pure HDMI from the GC will just have to upscale 480p to 720p/768p/1080p and that isn't intensive at all.

Compare this to the PS3 which natively outputs (and sometimes renders) at 1080p already. All you have to do is fine a LCD screen with little to no post processing and a good pixel response.

[emu_kidid]

ah ok, that makes sense. Have you tried a HDMIKey on a Wii? I'm curious how slow that is?

[ShortFuse]

All Wii HDMI upscaler are basically YPbPr Analog Component to HDMI which is analog to digital conversion and sometimes upscaling. The Wii doesn't have digital outputs while GameCube does (as backwards as that sounds). It's basically a Component + RCA Audio to HDMI adapter.

The "new" thing is to use the Wii U's HDMI, hack the Wii and run a ISO of the game off the SD card. Too complicated for many and also of questionable nature in terms of piracy.

[emu_kidid]

You can run devolution which requires the original disc at least once... but yeah that would look a bit suspicious in a competition, and not to mention the loss of GameCube controller support which everyone would want.

[tueidj]

Then you get people complaining that the wireless controllers introduce lag... even though their latency is 10ms at most, shorter than a single frame when running at 60fps.

[BenoitRen]

Wouldn't it be easier to use Wii consoles with a VGA cable instead?

How?

What do you mean, "how"? Please be more specific.

[pr0ton]

What do you mean, "how"? Please be more specific.

I'd like to know how you get native VGA (RGB-HV) out of your Wii. Only can find these component to VGA cables online, not very satisfactory.

[BenoitRen]

A component to VGA cable gets you VGA. I have one myself and I'm very happy with it. The quality is really good.

[pr0ton]

offtopic much:
Btw, just found out 0z0ne is quite active in the Oculus Rift scene to get HDMI>MIPI done. As I'm looking for a DP>eDP board we are both contacting Rozsnyo (Daniel), small world, lol. Too bad these FHD 5-7" screens don't just use an eDP connection. Now eDP and MIPI are both in the race as a LVDS successor?

[OzOnE]

Yep!

Work still in progress on that.
Actually, I have an e-mail from Daniel waiting for my reply (should really get on to that).

Also, it sounds like Chalk Elec are still working on a MIPI board, but they're worried that the software won't output in portrait mode (1080x1920).
I see that mode has been added to the software, but it's something that's difficult to test, as no standard monitors / TV's will accept it.

Not sure exactly how I'm going to do the kits for the Rift, but I took the poor thing apart yesterday (looks even simpler when it's apart).

(sorry, back OT)...
I'll be away this weekend at an 80's festival, but I've been messing with the GC HDMI mod...

Having trouble with the scandoubler as usual.
It's FAR simpler than the SDRAM version though, and only needs the FPGA itself (uses internal RAM blocks to buffer the lines).

It does display on a monitor OK, but part of the image is missing.
I think that this is due to it being 50Hz (PAL GC), so the monitor doesn't like it much, or I'm over-running the FPGA buffer area?

(my TV doesn't accept 50Hz / 31KHz via VGA, but the monitor does)

Code is about a million times tidier now though.
I should be able to debug it much easier via JTAG / SignalTap.

This is only for interlaced though ofc, 576p / 480p stuff will bypass the scandoubler altogether.

I don't really want to try soldering everything to the new US GC, so I'll try burning a 480p game disk again.
Actually, I forgot that you can hold X down to force NTSC with the Xeno modchip, so I'll try that too.

Might have to wait until after the weekend though.

OzOnE.

[pr0ton]

Ok, kits, cool. I like the Rift hype very much, people creating their own huge VR devices is interesting and fun to follow. Hope to step in one day.

Do you by chance know how much latency is involved by HDMI>LVDS(or MIPI) switching? I think DP>eDP is close to, if not zero. Don't think it will be much more than 1ms anyway, since LVDS is still common in desktop monitors.

Also noted that tueidj is quite sceptic about latency ("wired controllers belong to the past decade or else die"). Don't think he is at EVO level, but would pro-players really notice if you gave them an extra 10ms .

[OzOnE]

I don't think there will be any noticeable latency involved in the HDMI to MIPI board.

AFAIK, chips like the SSD2828 don't contain a frame buffer, so it's pretty much a direct conversion to the new protocol.

I don't think they even need to buffer any lines, as the newer panels have similar timings for 1080p as with PC's (I think?).

If a wireless controller is designed properly, there shouldn't be any noticeable delays either.
But, from having used various wireless mice / keyboards / controllers over the years, I don't think many of them have perfected it yet.

I'm using this wireless keyboard / mouse right now (Gyration), and I can always feel / see the slight lag.

At competition level, I can see how it makes a difference, especially with rapid button pressing like in Melee.
As you know, many pro PC gamers would swear by a "proper" wired keyboard / mouse, and this has been tested against wireless many times.

I'm sure there are some very good wireless setups available, with imperceptible lag, but you have to pay the extra for it.

OzOnE.

[tueidj]

To repeatedly press a button faster than 10ms would mean you're pressing it over 100 times per second. Nobody is anywhere near that fast.

[emu_kidid]

perhaps it's not the frequency of how many times you can push a button but getting the button pressed within a 10ms window, like on the reaction of another player doing a certain move/etc in close combat.