Down conversion to 240p using DVDO machines

[SGGG2]

Okay, tried RGBHV BNC with component adapters / T-sync combiner with the HD+, but it didn't work. It sees the signal but the picture scrolls horizontally and blanks out. Tried H and V only and every sync type in the menu as well.

[Blair]

Okay, tried RGBHV BNC with component adapters / T-sync combiner with the HD+, but it didn't work. It sees the signal but the picture scrolls horizontally and blanks out. Tried H and V only and every sync type in the menu as well.

thank you for testing that.

I'll try to confirm on my end when the BNC converter Jack's get here.

I've made more progress with 384p-60hz settings on both DVDO units (do you think your XRGB3 could handle that resolution?) (its a Horizontal sync frequency of 24kHz)

(Games: Mars Matrix, Marvel Versus Capcom) (384p isn't stable on my PVM-20L5 so all these are from my Sony multiscan monitor)

all games play at a solid 60 fps, with no frame doubling! (RGB interface readout is: 59.41Hz)


(Sega Dreamcast VGA to RGBHV) (VP50 Pro) [overscan 0.5%]

[720x384p-60hz VP50 on Sony E400 monitor]

[720x384p-60hz VP50 on Sony E400 monitor]

[720x384p-60hz VP50 on Sony E400 monitor]

(Sega Dreamcast VGA to ‎YPbPr component) (Iscan HD+) [underscan 0.4%]

[720x384p-60hz HD+ on Sony E400 monitor]

[720x384p-60hz HD+ on Sony E400 monitor]

[720x384p-60hz HD+ on Sony E400 monitor]

384P timings

Code: Select all

H – size 720
H – front 32
H – sync 72
H – back 32 

V – size 384 
V – front 8 
V – sync 4
V – back 8

frame lock: 60hz

[Blair]

notes:

because of the extra 144 lines, some games might need slight ratio adjustments to appear correct.

the scanlines themselves can be moved by adjusting the "overscan" and "underscan" settings in the scaler, basically acting like the even/odd switch of an SLG. only with way more precision.

(the games look and play fantastic, and the monitor looks way better than anything at my local arcade)


(I apologize for any ghosting or bleeding you might see in these pictures, it's not really noticeable with the scanlines but... I needed a long VGA cable and the one I have is kind of crappy) (and the camera is just an LG cell phone)

[Fudoh]

384p isn't neccessarily best for scanlined low-res content. It's more interesting for real hi-res content on a dual-sync cab. This way it can replace an UVC unit. On a 15/24khz arcade monitor you hardly get any scanlines with 384p content, instead you get a very solid semi-hi-res image.

[Blair]

I know what you mean, and it's true the scanlines aren't as visible as 240p mode, but for now it's the best compromise I could make for the vp50, if I wanted a 60Hz refresh rate. (still trying to figure out those timings)

and I mainly tested it on the HD+ to see how it compared.

overall, it's a nice gimmick for anybody that has a MultiSync monitor.

[Blair]

Okay, tried RGBHV BNC with component adapters / T-sync combiner with the HD+, but it didn't work.

Hey SGGG2 and Fudoh, I was able to get RGBs working on the HD+ (check it out)

(Sega Dreamcast)



the way I did it was connecting the Dreamcast VGA into an RGB interface and connecting the RGB and Sync line (BNC out) into the corresponding ports on the HD+

the reason it didn't work before with RGBHV was probably because the T connector wasn't combining the sync (I'm guessing).

but it does work and it can accept above 15 kHz, so now we know that at least.

(just have to figure out how to do it without the RGB interface to further simplify the chain. Fudoh, do you have any idea why the physical connection isn't combining the H/V sync? (I also tried using a Y-adapter and got the same result of failure before using the interface).

this solution looks/works better than using the VGA to component transcoder I was using ( it would sometimes lose sync on bright white backgrounds)

this is also a good way of getting any PC or other RGB signals into the HD+ without transcoding (it will also make 240 downscaling better for my set-up)



(edit)

doing some more research I came upon this



it's an RGB cable with a sync combiner circuit built-in, using this would eliminate the RGB interface from the chain (I'm assuming) as it's only purpose (in my current setup scenario) is combining H and V into composite sync. anybody here have any experience using them? (does anybody know where I can purchase one of these?)

of course the RGB interface is also great as a VGA/RGB switch, so that might make it worth keeping as part of a video chain. ( but it's also nice to have less power cords and other cables around for different setups)

[Fudoh]

(just have to figure out how to do it without the RGB interface to further simplify the chain. Fudoh, do you have any idea why the physical connection isn't combining the H/V sync? (I also tried using a Y-adapter and got the same result of failure before using the interface).

that's a problem with the signal level. It can work (and does, on BVMs for example), but it's never guaranteed to.

it's an RGB cable with a sync combiner circuit built-in

I've been using this (self-made though) for a while to connect RGBHV sources to the Framemeister's RGBs input. Here's the circuit:
http://shmups.system11.org/viewtopic.ph ... 41#p992941

[BuckoA51]

Will you be doing a full write-up on this experiment Fudoh?

[Xyga]

So I can't get any picture out yet, the only thing showing the TV is actually receiving a signal is the [->] symbol that more or less reacts to the changes I make.

Here's my first attempt setup, with a VP30 to start;

DC running VGA compatible game > VP30 (RGBHV BNC input) -> Sony crt TV scart input (BNC RGBs > Scart, sync line wired from H out to scart pin 20... I think)

VP30 current settings;

OUTPUT
BNC
Format: User
- Hshift 55
- Hsize 640
- Hfront 21
- Hsync 62
- Hback 55
- Vshift 20
- Vsize 240
- Vfront 19
- Vsync 6
- Vback 20
Ratio: 4:3
Sync Type: Composite (tried others but either mess up or do nothing)
Color Space: RGB
Framerate: 60Hz 101.47Hz (wtf ? and I can't get it down)

[Fudoh]

Remember that DC through VGA on the VP30 was flawed to start with - usually only working if you add a RGB interface in between. You might be better off by using a standard 480p component input signal.

[Xyga]

I doubt that's the issue at the moment, I've tried with the VP50pro and switched the source to 360 @ 480p (HDMI), and still no picture at all.

Maybe the culprit is my BNC>Scart cable, I'll have to check how it's wired for real.

[Fudoh]

If you set the output to component, you can use the composite input on your monitor and try with just a single BNC/cinch cable.

[Blair]

hi Xyga

Framerate: 60Hz 101.47Hz (wtf ? and I can't get it down)

sounds like the same limitation I'm experiencing with the VP50 Pro (does your VP30 unit have the abit 102 upgrade card inside?)

what model of CRT is this? and what resolutions does it support? (it probably won't show a picture until you can get down to 60Hz)

so far I've only been able to get the VP50 stable at 240p 100hz+ and 384p 60hz (I have been able to get it down to 240p 60hz vertical refresh rate, but the horizontal refresh rate was still 27kHz it needs to be down to 16kHz to be stable on most CRTs)

have you checked out any of the calculator links?

Code: Select all

Modeline "720x240@60" 12.63 720 752 792 824 240 245 248 253

H – shift 56
H – size 720
H – front 32
H – sync 40
H – back 32 
H – Total 824

V – shift 10
V – size 240 
V – front 5
V – sync 3
V – back 5
V – Total 253

res 240@60 lines
Pixel clock frequency 12.63

But my readouts look like this...

RGB interface: H - 27.22k V - 53.4Hz

VP50 Pro: 107.93Hz

[Xyga]

If you set the output to component, you can use the composite input on your monitor and try with just a single BNC/cinch cable.

How do I set it to output component ? I can't select that anywhere, there's the option for color space but it doesn't change anything.

I'll build a single BNC>composite cable and give it a try, yep. Hope it's not limited to that.

what model of CRT is this? and what resolutions does it support? (it probably won't show a picture until you can get down to 60Hz)

It's a standard European crt tv, with rgb scart input: Sony Trinitron Wega kdl-29ls35b.
No idea about it's signal range specs, but it's a pure 15KHz set naturally, nothing like a monitor for pc/progressive signals.

My VP30 has the ABT102 card installed yes.

I've checked the calculator links but I have no idea where to start...

EDIT:

Maybe the culprit is my BNC>Scart cable, I'll have to check how it's wired for real.

So the sync line is wired like this:
- center: Pin 20 (composite video input / Sync input)
- outer: Pin 18 (composite video input ground / Sync input ground)

[Blair]

My VP30 has the ABT102 card installed yes.

my current running theory is that perhaps removing the upgrade card in a VP30 might make it easier to stabilize 240p 60hz (making it more like the HD+ and less like the VP50 Pro) (is there any danger in removing the upgrade card once it's been installed?)

that way you could use the timings for the HD+, instead of the VP50. (my theory might be wrong, but I think it's worth a try if it's safe for your hardware)

if it works the way I think it might, you could use your VP50 feeding into the VP30 as a supplement for the performance loss from removing the card.

I've checked the calculator links but I have no idea where to start...

sorry, I haven't been here very long so I've just been under the assumption that everybody here is a videophile capable of reading Modelines like a second language, lol (I'm still a novice myself) (I can type up small beginner's guide later today when I have time).

[Xyga]

My VP30 has the ABT102 card installed yes.

my current running theory is that perhaps removing the upgrade card in a VP30 might make it easier to stabilize 240p 60hz (making it more like the HD+ and less like the VP50 Pro) (is there any danger in removing the upgrade card once it's been installed?)

It's not harmful but without it installed the lag skyrockets.

I've checked the calculator links but I have no idea where to start...

sorry, I haven't been here very long so I've just been under the assumption that everybody here is a videophile capable of reading Modelines like a second language, lol (I'm still a novice myself)

I know more or less what modelines are as I've been modifying/creating some for my PC>CRT 15KHz setup before, but I don't know how they'll help me for that kind of particular setup now.

I'm used to see my crt tv take anything 15KHz so what I'm trying to do here is pretty unusual and confusing to me, I haven't figured what's going on yet.

[Fudoh]

How do I set it to output component ?

output color space setting.

I would also recommend to try it without the ABT102 (if you don't mind of course). Without the ABT the VP30 is technically very close to the HD+. [also I want to know since I would get another VP30 if it works]

[Blair]

It's not harmful but without it the lag skyrockets.

right, that's why I was thinking you could incorporate the VP50+30, and eliminate that bottleneck (use the 50 for all the processing and the 30 for downscaling) (not the most eloquent solution, but it's worth a shot)

but I don't know how they'll help me for that kind of particular setup now

first you use the mod line generator, then plug that string into the calculator. and use those settings as your baseline for adjusting the scaler.

[Fudoh]

right, that's why I was thinking you could incorporate the VP50+30, and eliminate that bottleneck (use the 50 for all the processing and the 30 for downscaling) (not the most eloquent solution, but it's worth a shot)

without the ABT the VP30 - just like the HD+ - has a fixed processing path, so lag is the same, no matter what kind of processing you do.

[Blair]

without the ABT the VP30 - just like the HD+ - has a fixed processing path, so lag is the same, no matter what kind of processing you do.

really?

I noticed a big difference in lag when I Fed the VP50 Pro or the Edge Green into the HD+

perhaps I was just noticing the difference because of the de-interlacing modes?

well, even if the leg isn't improved by much you still get the benefit of better de-interlacing (quality?) and more inputs by chaining those other processors together.

[Xyga]

@Fudoh; I've tried changing output color space to YPbPr already but it doesn't do anything.

I'll try the VP30 without ABT102 later but I'm sure I have to solve my 'absolutely no picture' issue first.
There is obviously something wrong with my setup, my cable seems right though...

I'm still using the 360 @ 480p on HDMI-1 input, but with only the VP's front lcd to work it's kind of hard to figure what's going on (if i press the info button i only get the VP's firmware version).
Sorry guys the whole thing seems so unnatural for me, I mean how's the VP's meant to output 15KHz signals from anywhere to begin ? So the thread's big news for me but I realize I don't get how it works at all...

[SGGG2]

Excellent work, Blair! It didn't occur to me that the T connector may not be combining sync. I can't find that cable for sale anywhere.



This is pretty much how I feel. A beginners guide on the modeline calculators would be most welcome.

[Blair]

So the thread's big news for me but I realize I don't get how it works at all...

don't worry, I know it's all kind of murky at this stage. It was for me at least. Back when I was first testing out my crazy idea's and reporting them to fudo.

in simple terms your vp30 can easily output 240p 120hz. Great if you want to play on a VGA monitor with real scan lines. But not so great for playing on a 60hz only TV.

that's why I was suggesting to try it without the upgrade card, making it more like the older model capable of outputting 240p 60hz (easily playable on any 15hkz)

Excellent work, Blair! It didn't occur to me that the T connector may not be combining sync

Thanks!

I had a feeling it was something to do with the sync being off.

makes me wonder if there's a similar issue keeping your XRGB3 from recognizing any signal from the HD+

[Xyga]

Well I probably misunderstood because in the thread's opening post Fudoh says;
"some DVDO machines with custom timing support are so flexible, that they even support 15khz 240p output."
"It should also work on VP50 and VP30 units"
But if I understand what you're saying the VP30/VP50pro actually can't do it on real 15KHz sets, except for the HD+ and VP30 (w/out ABT102) which leaves only the choice to play with high lag (the standalone VP30 produces an awful 50+ms or something IIRC).

Basically they're not replacing devices like the Emotia, do I get that right ?

[Blair]

that doesn't sound right, I'm definitely getting way less lag than that from my current setup

50ms lag? Maybe you're thinking of the Edge or VP 50 (non pro) and one of those bugs

Basically they're not replacing devices like the Emotia, do I get that right ?

Emotias and uvc units are still useful, this is just another option for people.

[Fudoh]

Well I probably misunderstood because in the thread's opening post Fudoh says;
"some DVDO machines with custom timing support are so flexible, that they even support 15khz 240p output."
"It should also work on VP50 and VP30 units"

unless I tried it myself, I can just speculate. The initial posting was done after I got Blair's screenshots. On the 50Pro it was likely false alarm as it seems limited to a 24khz timing. HD+ seems fine, leaves the others to be tested.

[Xyga]

I see. Well I've just tried the VP30 without ABT102 and it's exactly the same behavior.
Puzzling... I'll investigate every step of the chain.

[Blair]

Right, that was before I knew what was going on with the refresh rate increase on the 50pro

I did the first few tests on a multi sync monitor before moving on to my L5.

Recent testing on the 50pro has me hopeful as I was able to get an almost stable image with 280p at 60hz but I've been focussing on the HD+ for now.

[Blair]

I see. Well I've just tried the VP30 without ABT102 and it's exactly the same behavior.
Puzzling... I'll investigate every step of the chain.

Did you try useing my most recent HD+ timeings?

Code: Select all

H – shift 42
H – size 720
H – front 24
H – sync 84
H – back 42 

V – shift 13
V – size 240 
V – front 17 (10 for the 14m2u)
V – sync 1
V – back 22

What was the readout from framerate?

Do you have an rgb interface? I have not been able to get any of this to work without incorporating one (or more) into the chain. (This whole process seems to be very picky about sync signals).

[Xyga]

If you set the output to component, you can use the composite input on your monitor and try with just a single BNC/cinch cable.

Just tried that and again no picture...

I see. Well I've just tried the VP30 without ABT102 and it's exactly the same behavior.
Puzzling... I'll investigate every step of the chain.

Did you try useing my most recent HD+ timeings?
What was the readout from framerate?

Yup. Both on the VP30 and the VP50pro.
101.47Hz again in both cases.
EDIT: I can force it down to 92.36Hz on the VP30 w/out abt102.

Do you have an rgb interface? I have not been able to any of this to work without incorporating one (or more) into the chain.

Nope I don't sorry. Did you try removing the RGB interfaces afterwards and see if it still works ?