BitBlitz: 15k RGB -> VGA

[Fudoh]

(bit OT, but I don't think that the Vehda unit would do 31khz RBsB or RGBs).

[robbo43]

Ahh, thanks. I thought the blurb for the VP20 suggested it would accept 576p as RGBs /RGsB through the relevant phono inputs. Good to know.

Back on topic!

[Fudoh]

It does 576p in YPbPr (component) colorspace, but from the menu I don't think it can be set to RGB colorspace.

[orbus]

This brings me to the next question, have you decided on input/output connection options yet?

This was also going to be my question.

Also wondered if you'd made any decision about 480i, since my primary use case would probably be for PS2. Been thinking about buying a GBS, but this project caught my interest.

Keep up the good work, by the way.

[Fudoh]

With 480i you must really differentiate between a few arcade titles (let's say Sengoku Blade or Dragon Blaze) and anything else running in 480i (RPGs, 3D games etc). On the later ones you really want good deinterlacing with motion adaptive handling and proper interpolation - that's not what the RetroPix is intended for.

[Crafty+Mech]

At a minimum for inputs there will be a 6 pin header for accepting RGB, and H/V, or composite sync. Once I have the prototype board built I'll have a better idea about form factor and can look at what other input connectors to include (like the 5 pin Jamma video connector common on the latest wave of import harnesses).

As for 480i support, I will say not at this time. I'll take another look at that option after the initial release.

I'm squeezing in several nights a week working through the remaining design issues. I'm also working an IT contract right now that is in crunch mode, so my days are pretty full with my "real" job

[orbus]

Ah okay. Sounds like this might not be the way for me to go then. I've got a Panasonic LCD I'm feeding with component from the PS2, and it just doesn't come out looking very good. Hoping a scaler/deinterlacer feeding 480p into the TV might look better, but I guess this project isn't it.

Out of curiousity Fudoh, when you mention distinguishing between 480i on some arcade games and everything else, what would the difference be? I imagine you'd need more sophisticated handling for telecined content, or for games that are using interlacing to implement special effects (i.e. flickering shadows). Anything else? I'd think most games would be straight up interlaced - just sending half their fields each cycle.

[Fudoh]

The difference is "true interlaced" output on the games you wan't to play compared to 240p titles running in 480i by adding a field offset (= shifting down every other field by one line).

[orbus]

Interlacing's always confused me a bit, so bear with me. I live in NTSC land (60 Hz), so I guess my assumption would be most games would output at a (nominal) 30 frames per second, and each frame would be divided into two sets of fields. Then you'd just have to weave those two field sets back together to get 30 fps 480p.

I take it that's not the case, and there's no guarantee that the fields from one cycle will line up with the fields from the next cycle, leading to potential artifacts?

[Fudoh]

No, they actually output at nominal 60 frames and just just drop half the lines of each frame. And that's why you can can't weave, but you need proper pixel adaptive deinterlacing where static areas are weaved, but moving areas are interpolated instead (both within the same frame).

[orbus]

Ahhhh, okay. That makes sense then, thanks.

And yeah, I imagine any kind of intelligent deinterlacing with interpolation would require buffering at least a frame or two, which would get decidedly more complex to implement. Nevermind the complexity of the actual processing. At that point I guess you'd want an IC that could do it for you.

Crafty, I may still want to order a Mini SLG from you at some point. Still figuring out what I'm going to do.

[Fudoh]

If you still have VGA on your TV, then I would start by getting an iScan Pro, usually around $60-80. Component interlaced input and VGA 480p output. Full compatible with the MiniSLG as well.

[orbus]

I do have VGA. Will take a look around on ebay when I get a chance, thanks.

[Crafty+Mech]

If you still have VGA on your TV, then I would start by getting an iScan Pro, usually around $60-80. Component interlaced input and VGA 480p output. Full compatible with the MiniSLG as well.

A few of my users have used the iScan Pro + mini SLG combo and have been really pleased with the results.

[XianXi]

Awesome work so far. If it's possible, can you incorporate RGB pass through?

[ZellSF]

How did I not know that someone was making a cheap lag free line doubler?

But, by no 480i support do you mean 480i titles won't show anything at all, or will it just drop half resolution or something?

[Fudoh]

480i will most certainly show. It just doesn't look very nice if you apply the same 240p doubling without compensating for the line offsets. The XPC-4 does it this way. With a line compensation you can get quite easily to look it like a XRGB1/2/3.

[dieKatze88]

I honestly can't wait to see these available for sale, because this sounds like its going to be killer.

[Adderall]

Any update on this?

No rush, just wondering if it's still being worked on

[Crafty+Mech]

Still working on it! Some final pieces are starting to come together. I'm planning to get a new demo video posted soon.

I recently built an RGB cable for my NTSC SNES so I could test the RetroPix design with a 15k source that was not quite 240p. Worked pretty well, but also realized a couple design considerations that need to be a bit more robust.

Progress was slow over the summer, but I've been ramping back up recently. I'm really excited to bring everything together into a working product. As a one-man engineering team this effort has been quite a haul, but I have learned a lot along the way about analog signal processing.

In some ways I wish my degree/minor had been flipped from Computer Science/EET to EET/Computer Science, but 18 years of software development has been good to me. Still I'm hoping this product will have some success and allow me to pursue a side business outside of programming. The mini SLG is selling well, but I need to add more products if I want to be able to take CraftyMech seriously as a side business. So stay tuned!

[BitFaced]

Wow, this sounds really promising (scanlines, under $100 price tag which is less in pounds, etc.) I assume for RGB SCART sources you'd use a Sync Strike or something? And what exact upscaled resolution is it?
And is YUV Component feasible for 240p games, as they aren't supported on Component on the HD TV I'm using?

[panzeroceania]

looking forward to your next update! looking good.

[rtw]

What's the form factor you are aiming for ?

Would be nice to have a JAMMA interface board like the Reco with a VGA connector on the side of it.

[Crafty+Mech]

Wow, this sounds really promising (scanlines, under $100 price tag which is less in pounds, etc.) I assume for RGB SCART sources you'd use a Sync Strike or something? And what exact upscaled resolution is it?
And is YUV Component feasible for 240p games, as they aren't supported on Component on the HD TV I'm using?

I'm still debating including a basic sync stripper as an option on the input. In either case, a 6 pin header on the board will accept 15k RGB as either RGBs, or RGBhv.

The input is not upscaled, but rather line doubled. So the output vertical resolution will be twice the input.

I don't have plans at this time for YUV input, but once the product is launched that feature as well as a few others is on the list for future consideration.

Form factor wise I'm trying to keep the board as small as possible, more in line with the size of the GBS-8200. No plans for a JAMMA edge on the board, but I will include the 5 pin video connector that is popular with the cheap JAMMA harnesses (RGBs), in addition to the standard 6 pin header (RGBs, RGBhv). I'm also planning on providing a 15pin dsub (VGA style connector) for input as well. So between those three connectors, that should pretty much cover getting input into the board from various RGB sources.

[Fudoh]

I'm still debating including a basic sync stripper as an option on the input.

if it's required, then I would certainly include it. Sure, you're aiming at PCB users, but at least half your buyers will be console users and it doesn't make much sense to force them into using an additional piece of equipment.

[brownvim]

Good Luck with this project, I will definitely be interested in buying the final product for my consoles

[dieKatze88]

I'm still debating including a basic sync stripper as an option on the input.

if it's required, then I would certainly include it. Sure, you're aiming at PCB users, but at least half your buyers will be console users and it doesn't make much sense to force them into using an additional piece of equipment.

Although my purpose for this would not need one, I would certainly appreciate one for other uses.

[BitFaced]

I'm still debating including a basic sync stripper as an option on the input. In either case, a 6 pin header on the board will accept 15k RGB as either RGBs, or RGBhv.

The input is not upscaled, but rather line doubled. So the output vertical resolution will be twice the input.

I don't have plans at this time for YUV input, but once the product is launched that feature as well as a few others is on the list for future consideration.

Form factor wise I'm trying to keep the board as small as possible, more in line with the size of the GBS-8200. No plans for a JAMMA edge on the board, but I will include the 5 pin video connector that is popular with the cheap JAMMA harnesses (RGBs), in addition to the standard 6 pin header (RGBs, RGBhv). I'm also planning on providing a 15pin dsub (VGA style connector) for input as well. So between those three connectors, that should pretty much cover getting input into the board from various RGB sources.

Linedoubled sounds good, 480p I assume. Not HD but HD TV's 480p doesn't look that bad and it's being scanlined anyway.
I just sorta wonder if I'll have to wait for longer after it's done or if I'd be able to use firmware to update it with the newer features after release, but that already sounds unlikely. Thanks for the reply!

if it's required, then I would certainly include it. Sure, you're aiming at PCB users, but at least half your buyers will be console users and it doesn't make much sense to force them into using an additional piece of equipment.

Yeaaaaaaaaaaaaaah he didn't make us buy a scanline generator. :3

[rtw]

@Crafty+Mech

Thanks for the info on connectors!

I don't know if your design includes an FPGA or CPLD but if it does please include a pin header so that people with the right hardware can upgrade the board without having to return it.

[Crafty+Mech]

Based on the feedback I'm hearing, I will definitely include a sync splitting circuit in the design.

And speaking of scanlines, that will also be an option built into the board, so no need to buy a separate mini SLG

The actual signal conversion is powered by logic gates and a few specialized chips and has no firmware. There is firmware, it powers the OSD and a few other functions (Amtel MCU). The chip will be a socketed dip, so upgrading will be possible by re-programming with an MKII or similar AVR compatible device, or just ordering a replacement MCU for a few bucks.

The form factor will depend a lot on if the whole board is SMD. I've been looking into DIY reflow ovens and they seem to work fairly well.

Having boards assembled by someone else is a major contributor to cost, so I am aiming to avoid that option. For another project, I'm also trying out an overseas pcb fabricator who was recommended to me. Prices are about 50% of what I pay to have my boards done locally, so we'll see what the quality is like.

From the start my goal has been a quality, reliable, no-frills line doubler. So although I want to accommodate as many users as possible, the first release will be "lean & mean" so to speak. With the delays of the past few months I am really anxious to finish putting this project together and release it into the wild.