OSSC (DIY video digitizer & scandoubler)

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Fudoh
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Re: DIY video digitizer & scandoubler

Post by Fudoh »

Plus if you live in Europe you can no longer avoid paying the import tax for anything coming from the US/Canada.
why's that ?
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Xyga
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Re: DIY video digitizer & scandoubler

Post by Xyga »

Looks like it's by default now. For a while I haven't been able to find anything sold and shipped from the US/Canada without added import tax.
It's not necessarily a bad thing since customs used to apply seemingly random and insane rates to some products like electronics devices.
A few years back I've payed 90€ of import tax for my vp30+abt, it would have been less if I had bought it today.

Still, there is no way around this tax now and it's inflating the total price, even the cheapest doubler I could find right now, an iScan Plus v2 costs 77€ if nobody comes with a higher bid, otherwise it's about 97€, and I don't think either price is worth.
There's also an iScan Pro for total 84€ from Spain, which is a bit over £60, it's not bad and certainly more desirable than your average Hd Box Pro, but as usual European sellers tend to sell for higher starting prices, and they're much less in numbers compared to US sellers.

Your best bet in Europe is either the UK or Germany, and NL a bit, but there aren't much units on sale and quite a few German sellers not having a PP account make things more difficult depending on your country's banking system (mine doesn't allow easy/online intl BT, unless you're a pro with a specific account).

I have to say whenever I encourage people on the French forums to buy something a bit better than the usual GBS or HDBP, they get discouraged by the scarcity, prices almost always higher than they were told, and sometimes difficult shipping/payment terms from the sellers.

So of course I believe cheap alternatives like a tweaked GBS or the BitBlitz or whatever could come out from the community would be awesome for tons of people.
I agree one can get good hardware with patience and effort, but to someone asking me the question I never say it's common to get decent doubling/scaling gear for cheap.
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ZellSF
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Re: DIY video digitizer & scandoubler

Post by ZellSF »

I think he's referring to eBay's new system? I buy stuff from Canada (outside of eBay) all the time and am not paying import taxes.

Anyway I did mean to specify a lag free line doubler, not the full on processing taking more than a frame that many alternatives do.
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Xyga
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Re: DIY video digitizer & scandoubler

Post by Xyga »

Yup sorry I forgot to mention that; I'm talking about eBay of course.
But this is the only option for many, many people.
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marqs
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Re: DIY video digitizer & scandoubler

Post by marqs »

ZellSF wrote:Do you have any plans of eventually mass manufacturing and selling this?

I want a linedoubler that's not XRGB3 prices already :(
It's still too early to say, but I've not ruled out that option yet. Making a sellable unit would require lots of extra work, including design of a proper user interface, case (or at least adding esd protection on the pcb), surveying pcb assembly services etc. Then there are obstacles like ridiculous HDMI licensing costs, so the HDMI TX would need to be replaced with a DVI/DP transmitter to avoid royalties. For now I'm concentrating on fixing the issues in current prototype, and then designing the next one.
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Fudoh
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Re: DIY video digitizer & scandoubler

Post by Fudoh »

Yup sorry I forgot to mention that; I'm talking about eBay of course.
you can still ask the seller to simply ship overseas by himself. The forwarding service ebay provides is really optional.
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Crafty+Mech
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Re: DIY video digitizer & scandoubler

Post by Crafty+Mech »

It's still too early to say, but I've not ruled out that option yet. Making a sellable unit would require lots of extra work, including design of a proper user interface, case (or at least adding esd protection on the pcb), surveying pcb assembly services etc. Then there are obstacles like ridiculous HDMI licensing costs, so the HDMI TX would need to be replaced with a DVI/DP transmitter to avoid royalties. For now I'm concentrating on fixing the issues in current prototype, and then designing the next one.
The HDMI licensing costs are indeed ridiculous. I'm really surprised that the audio market hasn't adopted a similar closed source digital signal standard. Or maybe they have, and I am just behind the curve. I love the HD quality, but I miss the analog days where the standards were open.

You can assemble your own pcbs with a little investment, and get nice results. For TQFP chips and smd parts, a solder mask + DIY reflow oven is a cheap solution that takes the pain out of SMD soldering. There are a couple different DIY reflow oven projects out there (one is on Kickstarter I believe) that basically are a custom controller board that replaces the stock controller in a toaster oven.
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Xyga
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Re: DIY video digitizer & scandoubler

Post by Xyga »

Why yes but you have to contact him beforehand and hope he agrees.
Don't know how it works for an auction but there's no button to remove the tax anyway, I guess you have to hold and ask the seller to redo an invoice.

Whatever, sorry for the redundancy here, but my point is it's not easy to get a decent scaler/doubler solution for as cheap as £50, such a low price really means luck. Except of course if you spend a lot of time lurking on the bay and forums and be the first to jump on the best possible offer.
Take just the iScan Pro or Ultra, you will need something like a scart>component solution to go along with it otherwise it's use will be very limited, and CSY-2100 clones sell somewhere in the £40-£50 already (maybe there's cheaper, idk).
Next thing to take RGB is an iScan HD I believe, or maybe one of the older Cinemateq or Vigatec ? There you are already easily over 100€ and it's mostly US and Germany.
Really I don't mean it's impossible but those are the common prices, cheaper opportunities are exceptions.

So... GO DIY HEROES ! :D
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marqs
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Re: DIY video digitizer & scandoubler

Post by marqs »

I've been quite busy with other things the last few weeks so there's been time only for few improvements and fixes. Since scandoubling and basic digitization have been working well for some time, I've been re-thinking about implementing 240p->720p conversion. I'm now quite confident it's possible to implement the feature on current hardware without requiring any aspect fix tricks from display. I calculated video mode parameters which would result if samplerate was set according to typical 256x240 and 320x240 modes, and tried corresponding modelines on a few displays using PC. If anybody is interested testing out a display's compatibilty, it's easy to set the custom 720p mode using Nvidia CPL (Windows) or by adding the following modeline in Xorg config (Linux):

Code: Select all

Modeline "1280x720_custom"  80.4078  1280 1370 1495 1705  720 732 741 786 -hsync -vsync
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bobrocks95
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Re: DIY video digitizer & scandoubler

Post by bobrocks95 »

Very glad to hear progress is still being made. I'll be much more invested when I get my FPGA board soon :)
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Re: DIY video digitizer & scandoubler

Post by Asbrandt »

I have a few questions, two for the sake of my own curiosity or knowledge;

1: The 240p <-> 480i switching is definitely fast from the video and shouldn't present any issues. Just for the sake of my curiosity though, where the black screens load transitions from the game itself, or are there any lost frames?
2: Is single field deinterlacing the same thing as field extension deinterlacing? Google wasn't being helpful in answering this question.

3: Does the 2-line lag time hold under an interlaced signal? If so, would a version that goes to VGA output be on the table after completion of this digital output version?
I suspect that may defeat much of the purpose of the project for you, but to my knowledge only the XRGB 2 and 3 have the fast-if-not-pretty deinterlacing option, and an alternative to those devices may be rather desired among CRT diehards.
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Re: DIY video digitizer & scandoubler

Post by undamned »

marqs wrote:I've been quite busy with other things the last few weeks so there's been time only for few improvements and fixes. Since scandoubling and basic digitization have been working well for some time, I've been re-thinking about implementing 240p->720p conversion. I'm now quite confident it's possible to implement the feature on current hardware without requiring any aspect fix tricks from display. I calculated video mode parameters which would result if samplerate was set according to typical 256x240 and 320x240 modes, and tried corresponding modelines on a few displays using PC. If anybody is interested testing out a display's compatibilty, it's easy to set the custom 720p mode using Nvidia CPL (Windows) or by adding the following modeline in Xorg config (Linux):

Code: Select all

Modeline "1280x720_custom"  80.4078  1280 1370 1495 1705  720 732 741 786 -hsync -vsync
Some progress is much better than no progress! :D My project time has been slowed to a crawl this year due to just everyday life stuff :? Keep it up!
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marqs
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Re: DIY video digitizer & scandoubler

Post by marqs »

Asbrandt wrote:I have a few questions, two for the sake of my own curiosity or knowledge;

1: The 240p <-> 480i switching is definitely fast from the video and shouldn't present any issues. Just for the sake of my curiosity though, where the black screens load transitions from the game itself, or are there any lost frames?
2: Is single field deinterlacing the same thing as field extension deinterlacing? Google wasn't being helpful in answering this question.

3: Does the 2-line lag time hold under an interlaced signal? If so, would a version that goes to VGA output be on the table after completion of this digital output version?
I suspect that may defeat much of the purpose of the project for you, but to my knowledge only the XRGB 2 and 3 have the fast-if-not-pretty deinterlacing option, and an alternative to those devices may be rather desired among CRT diehards.
1. There are a few blank frames during a mode switch. This is best shown in games where you have a normal<->hires -switch in a menu (e.g. some N64 games).
2. I think I got the term from Fudoh :) . Basically that is a improved version of bob/linedouble, where the other field is offset by one output line to reduce bobbing.
3. Yeah. With progressive signals the latency is around 1 input line, and offsetting the other field with interlaced material adds an extra half-line latency. I'm already using the VGA DAC on the FPGA board during testing, so it'd fairly easy to design a PCB with something similar. There's quite many possibilities one could do with similar setup - I'd be happy to see people expanding the design after the initial version is made public.
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Re: DIY video digitizer & scandoubler

Post by marqs »

240p->720p conversion is now implemented with 4 alternative sampling modes, which all produce similar output mode with 1280x720 active area. Based on initial testing, these seem to work great for displays which support the modeline I mentioned in an earlier post :)

The sampling modes are as follows:

M0: 1280 horizontal samples (of input line's active portion) - generic mode which produces 16:9 output
M1: 960 horizontal samples - generic mode which produces 4:3 output (160px wide black bars on both sides)
M2: 320 horizontal samples - pixel-perfect mode for 320x240 input (N64, PSX etc.), width tripled to 960 -> 4:3 output
M3: 256 horizontal samples - pixel-perfect mode for 256x240 input (NES, SNES etc.), width quadrupled to 1024 -> 5:4 output
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undamned
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Re: DIY video digitizer & scandoubler

Post by undamned »

This is exciting! :D
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marqs
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Re: DIY video digitizer & scandoubler

Post by marqs »

During a LAN party last weekend, I had a chance to test the current prototype with a few consoles I haven't tried connecting to it previously, e.g. a PS2:

Image
Guardian Heroes: Treasure Box running at 240p through component - output linetripled to 720p (total 263*3=789 lines) and scanlines added.

Image
Closeup (click for full-size img.).

The list of tested systems now include
  • Famicom (with Playchoice PPU): sync OK
    SNES: tested with US&PAL(+60hz mod) consoles, both have unstable sync at 60Hz, but 50Hz is OK
    PSX(PAL): sync OK both at 50Hz and 60Hz
    Saturn(JP): sync OK
    N64(US, RGB+region mod): sync OK both at 50Hz and 60Hz
    Gamecube(PAL) (via component): sync OK at 480i, 576i, 480p
    Wii(US) & WiiU(PAL) (via component): sync OK at all modes
    PS2(PAL, component/RGsB): sync OK at all modes
    XBOX(PAL with NTSC EEPROM): sync OK
    Dreamcast(VGA/640x480): sync OK
    Amiga 500(PAL): sync OK
    PC(up to 1280x1024@60Hz): sync OK
For some strange reason, SNES is the only machine so far which doesn't have a reliable sync. It seems like there's some variability in the hsync lengths/intervals as the PLL loses lock constantly, but I'll have to verify that with a scope. Does anybody know if there's something special in the sync signal of SNES (as far as I know, the timings should be pretty much identical to NES)? I've tried both csync and composite video but neither is stable...

Besides testing, I've been cleaning up the code as the most important features are now implemented (the last thing I added was support for masking borders). I'm planning to start design of the single-PCB prototype in a few weeks.
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Xyga
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Re: DIY video digitizer & scandoubler

Post by Xyga »

Looking GOOD ! :D
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Fudoh
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Re: DIY video digitizer & scandoubler

Post by Fudoh »

Actually looking GREAT!

Some versions of DVDO's FPGA versions had problems with the SNES's sync signal as well. I never had a chance to scope the signal though.
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undamned
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Re: DIY video digitizer & scandoubler

Post by undamned »

Looking super nice, sir! :D
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Re: DIY video digitizer & scandoubler

Post by emphatic »

Very nice indeed! 8)
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Re: DIY video digitizer & scandoubler

Post by fluxcore »

That's some very impressive news. I imagine using a sync stripper would make no difference to the 60Hz SNES results, if you tried CSYNC anyway... hrm.
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marqs
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Re: DIY video digitizer & scandoubler

Post by marqs »

I had a look at SNES csync signal with a scope:

Image
Horizontal sync pulses.

Image
Vertical sync pulse, lasts 3 lines. Equalizing pulses on 3 previous and 3 following lines.

Image
End of vsync zoomed in.

Image
Closeup of a rise/fall transition.

At least to my eye the signal looks quite normal without anything extraordinary - the transition edges perhaps aren't as sharp as they could be but not that bad either.

After further testing with the scope, I discovered that the sync loss originates from TVP7002's PLL losing lock a few lines after vsync, after which the PLL on FPGA naturally loses lock and output sync temporarily gets unstable. As with other video digitizers, TVP7002 uses a 'coast'-signal to freeze PLL frequency before vsync portion where proper hsync edges may not be available for reference. A couple lines after vsync, coast is disabled and PLL returns to normal operation. My guess is that PLL frequency drifts too much during the coast, which would explain the eventual PLL lock loss. I decreased the coast duration from the recommended values to minimize drift, after which TVP7002 PLL didn't lose lock anymore and output sync stabilized :). I still don't understand why none of the other consoles have this problem, though...
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Re: DIY video digitizer & scandoubler

Post by SmokeMonster »

Could you please also test the Turbografx16 or PC Engine's sync? It seems to be giving lots of people problems with certain scalers.
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marqs
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Re: DIY video digitizer & scandoubler

Post by marqs »

SmokeMonster wrote:Could you please also test the Turbografx16 or PC Engine's sync? It seems to be giving lots of people problems with certain scalers.
I'll test MD & PC Engine when I get a chance to play around with one, hopefully in near future.
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Re: DIY video digitizer & scandoubler

Post by viletim »

marqs,

The video from SNES has one less pixel every other field. This reduces composite video artefacts apparently. The NES does it too (both graphics systems were developed by the same company), though maybe not the Playchoice.

A good video game oriented scaler should be able to recover from a slightly mistimed pulse very quickly, ideally on the next line.

Also, only the leading edge of a sync pulse is used for timing. The trailing edge should be ignored.
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marqs
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Re: DIY video digitizer & scandoubler

Post by marqs »

viletim wrote:marqs,

The video from SNES has one less pixel every other field. This reduces composite video artefacts apparently. The NES does it too (both graphics systems were developed by the same company), though maybe not the Playchoice.

A good video game oriented scaler should be able to recover from a slightly mistimed pulse very quickly, ideally on the next line.

Also, only the leading edge of a sync pulse is used for timing. The trailing edge should be ignored.
Thanks for the info!

That probably explains why the issue only occurs with SNES, especially if Playchoice generates "normal" sync.

The video digitizer IC I'm using (TVP7002) has a register for adjusting line length tolerance, but perhaps it won't help if the missing pixel occurs during coast - I've tried increasing the tolerance and it didn't help by itself in this case. Luckily, reducing the coast duration did the trick and fixed the sync.

Unfortunately, there no setting to select which sync edge is used as the PLL reference. The chip is likely not designed with non-standard video signals in mind, but overall I'm quite satified with its operation and the amount of settings to tweak. The only major 'bug' I've noticed so far is the handling of noninterlaced signals which always indicate odd-field, but it seems that neither ADV7441A inside Framemeister handles that correctly.
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marqs
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Re: DIY video digitizer & scandoubler

Post by marqs »

The design files of the current board are now public and available here. They may be helpful for anyone with DE2-115 or similar FPGA board and interested in building a video scan converter. I'd be also interested to hear comments about the current design (rtl, software, pcb etc.) before finishing the pcb for follow-up standalone board.
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Re: DIY video digitizer & scandoubler

Post by fluxcore »

marqs wrote:The design files of the current board are now public and available here. They may be helpful for anyone with DE2-115 or similar FPGA board and interested in building a video scan converter. I'd be also interested to hear comments about the current design (rtl, software, pcb etc.) before finishing the pcb for follow-up standalone board.
Any idea for a rough target price for standalone? Looking at considerably more than an xrgb-mini for the dev board alone is a bit intimidating!
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marqs
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Re: DIY video digitizer & scandoubler

Post by marqs »

fluxcore wrote:
marqs wrote:The design files of the current board are now public and available here. They may be helpful for anyone with DE2-115 or similar FPGA board and interested in building a video scan converter. I'd be also interested to hear comments about the current design (rtl, software, pcb etc.) before finishing the pcb for follow-up standalone board.
Any idea for a rough target price for standalone? Looking at considerably more than an xrgb-mini for the dev board alone is a bit intimidating!
I wouldn't expect anyone to buy a dev board just for this, but there are also cheaper boards for which the design could be easily converted. For example, Cyclone V GX Starter Kit is "only" $179 and it has newer FPGA and on-board HDMI transmitter.

As for the standalone, it's still hard to give an estimate. Considering that the required extra ICs are not that expensive, I'd guess that you could buy all the necessary parts for yourself with around $50, plus perhaps $30 for the PCB. The prices would naturally go down with higher quantities, so if several people were interested building one, ordering the components and PCBs in a larger batch would be beneficial.
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undamned
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Re: DIY video digitizer & scandoubler

Post by undamned »

Super cool! :D
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