OSSC Pro

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GK6475
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Re: OSSC Pro

Post by GK6475 »

I'm mostly having gamma and white temperature issues anyway, so 1D LUT functionality would be perfectly fine.
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VEGETA
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Re: OSSC Pro

Post by VEGETA »

I wanted to ask if such projects can be implemented on anything else than FPGAs? like very fast powerful MCUs or linux-capable processors.

since FPGA scene will not get better anytime soon if ever... having a B plan is always best.

one idea came to me was to use something like RPi to take pure digital 30-bit video then use its playing software like MPV to output it to HDMI. MPV is extremely fast, so bottleneck will be stages before.

looking to your opinion on this.
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Guspaz
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Re: OSSC Pro

Post by Guspaz »

marqs wrote:
GK6475 wrote:Would it be possible to implement 3D LUT profile applying at some point for the OSSC Pro? Would love to get some proper gamma/color correction on my CRT displays.
For 8bpc (bits per channel) a 3D LUT would need (2^8)^3=16.7M entries, thus it doesn't fit into FPGA block RAM. Storing it in external DRAM is neither feasible as that means a random access for every pixel which would be very inefficient and jam the interface especially on higher resolutions. I'm more towards a CMU approach which would have 3x1D LUT on both input and output side with a 3x3 CSC matrix in between.
AFAIK (and I might be wrong here), 3D LUTs almost always use interpolation from a dramatically smaller array. There are probably only thousands or tens of thousands of entries.
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jay_are
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Re: OSSC Pro

Post by jay_are »

Hey I'd like to hear more details about the composite output the OSSC Pro would have. (I know S-Video and everything else is cleaner but I want Composite for the specific look of it)

I've just learned today that there's actually nothing out there that has good enough quality over composite output to play games, except the Raspberry Pi!
And even then the Raspberry Pi is not entirely perfect. To me, it's consoles like the SNES, PS1 and PS2 that have the most perfect quality over composite, because they have a way of eliminating artifacts (or "rainbows" more specifically), where the Raspberry Pi is almost the same as those, except the "rainbows" or artifacts are more noticeable because they're static, where consoles kind of blend it between frames somehow.

There are converters out there that can take for example 240p (15khz) from component and convert to composite, and I've never used them but considering how all these consoles have their own way of handling composite, I always wondered how these converters look, though I didn't think they would be too different from at least one of the consoles most people played. But I read online that that's not the case at all! There's Mike Chi's VGA2NTSC device, which apparently "is not synchronized to the origin video clock resulting in more color fringe artifacts" (quoted from his page).
Someone uploaded a little video of the VGA2NTSC with composite and it looks like you can see artifacts while the image is still!! Kinda just like it was 480i.

Next I looked at Axuworks's RGB-2YC, and someone on reddit describes it like this: "The composite out from this is significantly softer than most consoles' original composite, perhaps only with the exception of a Sega Genesis which is really blurry and terrible originally, but even there the RGB-2YC's composite video has other slight visual artifacts in addition to the blurriness.".
(Not being as blurry as a Sega Genesis sounds good enough, but I'm worried about the other "slight" visual artifacts mentioned because I wouldn't want it to be worse than that console.)

So I'd like to know exactly what I can expect from an OSSC Pro or if there's anything else out there that can at least output a console-like composite signal (Even if it needs to be fed 15khz RGB because the Retrotink 5X already covers that, and I'd be willing to buy it for this.)

Thank you!
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bobrocks95
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Re: OSSC Pro

Post by bobrocks95 »

Unless it was talked about for a GPIO expansion module, the OSSC Pro only has plans for a composite input being added via expansion. If you're adamant about having a full composite setup you're either at the mercy of each individual console's DAC or picking up one of the converters you mentioned to put at the end of your chain. Scalers like the Retrotink 5x Pro of course have some composite-like filters you can add, though you might not be happy with them and I assume you're using an actual 240p/480i CRT (though you could get an HDMI to component converter).
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jay_are
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Re: OSSC Pro

Post by jay_are »

bobrocks95 wrote:Unless it was talked about for a GPIO expansion module, the OSSC Pro only has plans for a composite input being added via expansion. If you're adamant about having a full composite setup you're either at the mercy of each individual console's DAC or picking up one of the converters you mentioned to put at the end of your chain. Scalers like the Retrotink 5x Pro of course have some composite-like filters you can add, though you might not be happy with them and I assume you're using an actual 240p/480i CRT (though you could get an HDMI to component converter).
Man, I thought I was 100% sure this was confirmed to have a composite output expansion, but I looked through the thread and found nothing.
Could I have misunderstood something?
I can only find an older post where I confirmed to you with a link that it had downscaling haha.
Last edited by jay_are on Sat Mar 18, 2023 12:02 am, edited 1 time in total.
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bobrocks95
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Re: OSSC Pro

Post by bobrocks95 »

I definitely could have missed it, but I can't imagine it's a highly requested feature.

For the other converters you mentioned, since composite's quality is going to vary so much based both on your sources and the final display's comb filter, you'd probably have to buy each just to really see for yourself. Reviews mentioning "slight artifacts" isn't very helpful considering composite is full of very glaring artifacts to begin with- rainbow banding, dot crawl, etc. Converting to it is essentially going to add some degree of those artifacts regardless...

It also seems quite wasteful to me to buy a $4-500 upscaler so you can output 15kHz composite out of it, there has to be a cheaper solution that looks about as good. People on these forums have probably bought plenty of niche equipment just as overkill though.
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jay_are
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Re: OSSC Pro

Post by jay_are »

bobrocks95 wrote:I definitely could have missed it
Hehe if you missed it, I won't blame you, cause I can't find the posts that mentioned it. I'm starting to suspect I misunderstood the whole deal. As in, there will be composite "input" expansions, not "output", but maybe I just didn't realize the difference? I dunno.
bobrocks95 wrote:isn't very helpful considering composite is full of very glaring artifacts to begin with- rainbow banding, dot crawl, etc. Converting to it is essentially going to add some degree of those artifacts regardless...
Yeah I know it isn't very helpful, but if they're complaining, it must be because it just simply isn't as good as the output from a typical game console, which is what I'm looking for
I do understand that composite is gonna have artifacts regardless, that's what I want :mrgreen: just that it has to be exactly like what either an SNES, GameCube, Wii, PS1, PS2, Saturn or Dreamcast would do, either would work for me with pretty much every game I want to emulate since all of these actually handle artifacts very similarly, in ways that a Raspberry Pi or most converters don't seem to do. I can't believe it's not a highly requested feature considering how many TVs only had up to composite.
bobrocks95 wrote:there has to be a cheaper solution that looks about as good
I know right?? That's what I used to think too, believe me, I wish I could have just gone to walmart, buy a $20 VGA to Composite converter, and that it would have a 240p option that would look like the typical game console because presumably it would have just been made with the same parts or designs. It really did not ever seem this complicated at all.

BTW, I have an Extron Emotia since 2007 (God bless that SCANLINES DEMYSTIFIED article), but even these device's composite output look uglier than game consoles. I also found issues like inferior black level, a seemingly lower color depth (it would make some specific colors look like they're missing), and I heard that it would at least add a frame of lag or something. It affected S-video, too, only difference being that S-video had no dot crawl or rainbows, so I used to emulate games like this, but eventually the clean signal felt like it's missing something. It's always a lot more exciting and real to me when I see an SNES doing its own beautiful composite. (Although, as I type this, I'm starting to wonder how it S-Video would look with Blargg's Composite filter, but even if that looked great, that filter won't just be available for every application like PC games.)
bobrocks95 wrote:It also seems quite wasteful to me to buy a $4-500 upscaler so you can output 15kHz composite out of it
So with all of that being said, now you know why I'm willing to go the overkill route at this point if that's what it takes, can't be cheap if I'm too demanding, right? :wink: For something to have been bothering me since the early 2000's, clearly the money would be worth it.
The only thing left for me if the OSSC Pro can't do it, is to go even more overkill, win the lottery, hire people that could design the device that does what I'm expecting, mass produce, and sell it at Walmart or whatever like god intended.
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bobrocks95
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Re: OSSC Pro

Post by bobrocks95 »

What was the issue again with just using each console's original composite output?
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jay_are
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Re: OSSC Pro

Post by jay_are »

bobrocks95 wrote:What was the issue again with just using each console's original composite output?
Nothing wrong with the original consoles, but emulation is just a lot more convenient, fully featured, cost effective and green for the environment of game sales.
:shock: is it not the most amazing thing to make any modern device be able to output with the signal quality of a classic console?
Imagine someone with a massive gaming PC full of gaming rainbow parts, and then you attach an HDMI to Composite device to it and now it looks like an SNES on a TV. The thought is so silly that this alone makes it all worth it!
Not just that, but being able to do it to Nintendo's official mini consoles or even any console up to the PS5/XSX which contain classic games re-released on them. Also being able to play PC games that would fit inside the CRT res, or make my own games and play them through composite specifically (to force myself to design with the limits of composite in mind like most classics)
Being able to do this to all those SBC's that are like Raspberry Pis too. It's a bummer that the Raspberry Pi has to be the only one capable of Composite 240p output, and all just because no one made a simple HDMI converter that would have worked on everything and be future proof.
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marqs
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Re: OSSC Pro

Post by marqs »

Guspaz wrote:AFAIK (and I might be wrong here), 3D LUTs almost always use interpolation from a dramatically smaller array. There are probably only thousands or tens of thousands of entries.
Sure, that's possible if some loss of precision is acceptable.
VEGETA wrote:one idea came to me was to use something like RPi to take pure digital 30-bit video then use its playing software like MPV to output it to HDMI. MPV is extremely fast, so bottleneck will be stages before.

looking to your opinion on this.
Once you have properly formatted video frame(s) in RAM, CPU/GPU could certainly process it easlly from there. However, how were you planning to get data from video ADC there without any CPLD/FPGA in the chain? By using some off-the-shelf DCFIFO chip, fetching data from it via GPIO and spending tons of CPU cycles to process it into proper format?
jay_are wrote:Man, I thought I was 100% sure this was confirmed to have a composite output expansion, but I looked through the thread and found nothing.
Could I have misunderstood something?
I can only find an older post where I confirmed to you with a link that it had downscaling haha.
There is currently only an expansion card for analog RGBHV output, but you could modify it and and add RGB->composite/s-video encoder chip like BH7236AF in there.
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jay_are
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Re: OSSC Pro

Post by jay_are »

marqs wrote:
jay_are wrote:Man, I thought I was 100% sure this was confirmed to have a composite output expansion, but I looked through the thread and found nothing.
Could I have misunderstood something?
I can only find an older post where I confirmed to you with a link that it had downscaling haha.
There is currently only an expansion card for analog RGBHV output, but you could modify it and and add RGB->composite/s-video encoder chip like BH7236AF in there.
Wow, thank you for confirming! I am mind blown that this entire time I've been dreaming about something that was not even true. :oops:
Well hey, at least it can be modified! Although at that point it sounds like the result would be similar to the other converters, unless that chip in particular is special?
I guess I'll wait and see if this ever materializes and then if anyone mods it! In the meantime I'll try whatever converters I can find. Thanks again!
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Unseen
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Re: OSSC Pro

Post by Unseen »

marqs wrote:
Guspaz wrote:AFAIK (and I might be wrong here), 3D LUTs almost always use interpolation from a dramatically smaller array. There are probably only thousands or tens of thousands of entries.
Sure, that's possible if some loss of precision is acceptable.
IIRC older Lumagen scalers implemented just a 5x5x5 3D LUT for color correction and it seems that was already quite useful. Their current devices are 17x17x17, still far from the full 256^3.
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VEGETA
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Re: OSSC Pro

Post by VEGETA »

Once you have properly formatted video frame(s) in RAM, CPU/GPU could certainly process it easlly from there. However, how were you planning to get data from video ADC there without any CPLD/FPGA in the chain? By using some off-the-shelf DCFIFO chip, fetching data from it via GPIO and spending tons of CPU cycles to process it into proper format?

can't it just take the bits directly from the video adc via gpio with sync then do what it needs to be done? i mean pi or similar devices are becoming more and more powerful, worth investing on imo.
GK6475
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Re: OSSC Pro

Post by GK6475 »

Any updates on when the OSSC Pro is coming out?
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TooBeaucoup
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Re: OSSC Pro

Post by TooBeaucoup »

GK6475 wrote:Any updates on when the OSSC Pro is coming out?
I believe Marqs has mentioned that the end of 2023 looked better, but don't count on it.
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bobrocks95
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Re: OSSC Pro

Post by bobrocks95 »

I go poking around looking at FPGA manufacturing lead times whenever this comes up, and apparently Xilinx (Spartan series) FPGAs are finally improving rapidly, according to some sources https://info.fusionww.com/industry-insi ... %20supply.

Still see 52 week lead times on plenty of FPGAs though.
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marqs
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Re: OSSC Pro

Post by marqs »

bobrocks95 wrote:I go poking around looking at FPGA manufacturing lead times whenever this comes up, and apparently Xilinx (Spartan series) FPGAs are finally improving rapidly, according to some sources https://info.fusionww.com/industry-insi ... %20supply.

Still see 52 week lead times on plenty of FPGAs though.
The problem is that no supplier is able to give a solid date for availability. I've received such 52 week lead time estimates over 1.5 years ago with no sign of delivery yet. That was for cheaper Cyclone IV/10LP parts - no sane person would pay for expensive Cyclone V chips in advance without a guaranteed delivery date.
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bobrocks95
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Re: OSSC Pro

Post by bobrocks95 »

Yeah I take it "52 week lead time" is pretty much just shorthand for "absolutely no clue when this part will be available".

I still haven't been able to find out what industries are buying up all the FPGA supply (military?), or why both AMD and Intel seem to have been completely unable to ramp up production capacity in any way whatsoever. Or maybe I'm wrong in thinking that most tech sectors have recovered supply chain-wise? FPGAs seem to be the major outlier.
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kardus
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Re: OSSC Pro

Post by kardus »

Been out of the scene for a while, apart from the OSSC Pro is gbs-control only decent option for downscaling 480-1080p to 240p? I have an 203xi and I remember before I was considering using a VSC unit in tandem with it but if I recall that output was not really true 240p or flawed in some way. Can I downscale with OSSC dexx..?
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bobrocks95
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Re: OSSC Pro

Post by bobrocks95 »

RetroTink 5x Pro also offers downscaling from <= 720p input to 240p/480i output.
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marqs
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Re: OSSC Pro

Post by marqs »

VEGETA wrote:can't it just take the bits directly from the video adc via gpio with sync then do what it needs to be done? i mean pi or similar devices are becoming more and more powerful, worth investing on imo.
Unfortunately it's not that simple. If RPi etc. had dedicated HW block that could read clocked video data from GPIO and DMA it to RAM, then things were more feasible.
kardus wrote:Been out of the scene for a while, apart from the OSSC Pro is gbs-control only decent option for downscaling 480-1080p to 240p? I have an 203xi and I remember before I was considering using a VSC unit in tandem with it but if I recall that output was not really true 240p or flawed in some way. Can I downscale with OSSC dexx..?
OSSC Pro and DExx are capable of downscaling, but the latter officially supports only up to 110MHz sampling clock (1280x1024@60).
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VEGETA
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Re: OSSC Pro

Post by VEGETA »

well, another option would be a dedicated scaler IC like the new MDIN-620 which supports up to 4k60, better than all FPGA scalers. I know feature-wise could not be as flexible as FPGA but still doable. I got pricing for this IC to be just 31$, but the company requires you buying quantity in order to get support, which I could not do but maybe you can xD. these ICs are guaranteed to stay in market and be available for sure. No reason why they are not used in such projects but ultimately your choice and your decision.
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Re: OSSC Pro

Post by Konsolkongen »

Would such a chip be any good though? If it's just made for video material it could introduce all sorts of nastiness like edge ringing and add additional lag. The scaler chip in the XRGB-mini was pretty terrible.
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VEGETA
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Re: OSSC Pro

Post by VEGETA »

Konsolkongen wrote:Would such a chip be any good though? If it's just made for video material it could introduce all sorts of nastiness like edge ringing and add additional lag. The scaler chip in the XRGB-mini was pretty terrible.

this chip manufacturer and I-chips are top of the line manufacturers, their chips are not like any bad stuff so you can safely expect top performance. they do have dev boards available but as I mentioned, they require buying bulk chips for support and their dev boards are expensive. being an ASIC is one step already above FPGAs but performance wise testing is the real key.
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Re: OSSC Pro

Post by XtraSmiley »

It's been another few months, any update on supply chain? Still looking like late 2023 for when this might be available?
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marqs
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Re: OSSC Pro

Post by marqs »

XtraSmiley wrote:It's been another few months, any update on supply chain? Still looking like late 2023 for when this might be available?
A number of FPGAs are now on order for a modest pilot batch so in best case end of the year launch is possible, but early 2024 is more likely. Pricing and availability of FPGAs are still far from normal, but definitely better than half a year ago.
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Re: OSSC Pro

Post by vol.2 »

No doubt. Speaking from experience, it's mostly the big companies that have had large quantities of parts backordered for a long time that are starting to get up to speed
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VEGETA
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Re: OSSC Pro

Post by VEGETA »

well, you are getting intel fpgas right?

i believe intel, amd (xilinx) are on very high demand. besides lattice (who people always whine about) you probably should take a look at PolarFire FPGAs from Microchip. I don't see people talking much about them, probably worth a try.


+ I noticed for a while that main video ADC is now obsolete! with no replacement. probably you should get another one before releasing but it is up to you.
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Re: OSSC Pro

Post by Xenphor »

Does anyone know if the OSSC Pro will support Retro PCs in a more comprehensive way? With the current OSSC I'm able to do 640x480 up to 85hz on one of my monitors (1080p 240hz freesync). It can also do 320x200@70hz in DOS. Unfortunately my other monitor (1080p 360hz Gsync native) doesn't really play nice with the OSSC at all.

So I'm wondering, with the OSSC Pro being a proper scaler, if it will support resolutions above 640x480 at higher refresh rates while potentially being more compatible? I don't expect 120hz+ but maybe 800x600 or 1024x768 at up to 85hz which were common back in the day. At the very least, making 640x480 up to 85hz more compatible would be nice.
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