Down conversion to 240p using DVDO machines

[Blair]

Fudoh, my XRGB-3 loses the signal with these timings. Any suggestions?

try my improved timings, posted on page one. and tell us how it goes.

But when the VP50 goes below 330 lines the TV gives up with invalid signal. Using PS2 at 480i. Would be interested to see if it works with a real CRT TV. (which I don't have anymore).

Do you have framerate setting on "lock" or "unlock"? That can have an effect on stability of the timings below 330 lines.

What is the television's maximum refresh rate? And HDMI version? (My current posted timings for the VP50 in 240p need a monitor capable of at least 120Hz, your HDMI dongle might be 60Hz only)

It's possible but I won't be able to test that unfortunately. No cables, and the TV doesn't do 240p over component anyway.

Actually, it might (what brand is it?) My Samsung LCD does 240p over component but it has to be a resolution of at least 640x244 or 720x240.

right now I'm working on stable 384p 60hz (24khz) timings for the V50, but 240p 60hz also seems within reach. (try to get 720x384p 60hz working on your current setup).

[Unseen]

- the VP50Pro might have a DAC limitation and not be able to reach down to true 15khz

Have you tried 1280x240 instead of 720x240?

[SGGG2]

Hi Blair,

Your posts weren't there last night after I made mine, very strange. Thanks for the help, but so far the timings aren't working properly. With your first set the image is squashed in half vertically and adjusting scanlines on the XRGB has no effect:



With the second set, the XRGB looses sync when V - front is goes above 14 or 15. Unfortunately, I have a whole chain of devices but everything so far points to the issue being between the HD+ and XRGB itself. I imagine it's just an issue of figuring out the proper timings, but I'm out of my depth here.

[Blair]

Hello.

SGGG2,. what sync type is your HD+ outputting? (composite, H- V+, et cetera)

can you get a stable/good image with stock resolutions from the HD+ (480p, VGA, et cetera)

Have you tried other systems besides the Dreamcast?

[SGGG2]

VGA works fine. It's has the exact same issues with 480i from a PS2. I unlocked the output of the HD+. I'll see if I can check the rest when I get back from work tonight.

[Blair]

VGA works fine. It's has the exact same issues with 480i from a PS2. I unlocked the output of the HD+. I'll see if I can check the rest when I get back from work tonight.

have you also tried adjusting V-shift? (try to get the picture in the middle, and make sure its not just a centering problem)

also, what type of display are you using? (CRT, LCD, Plasma)

Does the XRGB have a Display or signal info readout? (if so, what does it say about the incoming signal?)

are you sure you have the HD+ set to 4:3 and not 16:9? (input and output) (make sure lens is "off")

does the xrgb have auto screen ratio modes? 720x240 would be considered a "wide" resolution. but a CRT will just display it as a normal 4:3 image...

hardware video scalers, like the XRGB would most likely see it as a Wide or 16:9 resolution, so you might have to adjust something in the XRGB)

Do you have any RGB interface Device?

this is the XRGB3, right? (how is it connected to your display?)

How are you connecting the HD+ to the XRGB? (i'm assuming its with a VGA cable) are we sure the XRGB can accept 240p signals on its VGA port? maybe try the D-terminal input or the JP21 port.

[SGGG2]

I doubt it's a centering issue, scanlines would work if the XRGB-3 recognized it as a proper 240p signal. When I enable 4:3 on the iScan the image becomes squished horizontally with bars on the side.

Signal chain is VGA to Component transcoder / iScan VGA / XRGB VGA / Gefen VGA to DVI Scaler Plus / LCD monitor. The XRGB says "No Signal" when it's losses sync, I don't remember otherwise. The Gefen hasn't lost sync with the XRGB once. I have an Extron RGB interface with readout display I can add between the HD+ and XRGB.

I'll have an hour or so to mess around sometime tonight.

[Blair]

I doubt it's a centering issue, scanlines would work if the XRGB-3 recognized it as a proper 240p signal.

but are we sure the XRGB3 can take a 240p source on its VGA port?

When I enable 4:3 on the iScan the image becomes squished horizontally with bars on the side.

you have to maintain a consistent aspect ratio, the Iscan HD+ should be set to 4:3 if you are using a 4:3 source. (use the XRGB ratio settings, or the 16:9 mode on your LCD TV to stretch the image if you want to fill the screen).

I have an Extron RGB interface with readout display that I can add between the HD+ and XRGB

the RGB interface should also help as a sync combiner, all my CRTs needed it to display a stable image. that might also be part of your issue.

also, please take larger photos (if possible).

thanks, and good luck.


(edit)

when you try your next attempt, make your settings exactly like mine (by the way, what firmware version is your HD+?...my unit is: v2.02-5.6-2.32)

Code: Select all

HD+ settings


[Aspect ratio]

Input AR - 4:3

Zoom - (hor - 100) ( ver - 100)

Pan -  (hor - 0) ( ver - 0)

Borders - (hor - 0) ( ver - 0)

[Input adjust]

Border level - 0

Overscan - 0

DVI input - auto

Film mode - off

Audio input - off

AV lip-synch - 0

[Picture control]

Sharp - off

Y/C delay - 0

CUE - correction - off

[Configuration]

HDCP Mode - off

[Output setup]

Analog/digital - VGA analog

Format - user

Aspect ratio - 4:3

Sync type - composite

Color space - RGB

Framerate - 60Hz lock


[end]

Video chain: ‎YPbPr video source = Iscan HD+ = VGA cable = RGB interface 203rxi (dip switches: DDSP: on) = RGBs cables = Sony PVM-20L5. [interface readout' H:16.61k V:59.9hz]

(Also try: DDSP: off as my 14m2u doesn't like it).

[SGGG2]

The XRGB-3 works swimmingly with 15Kz input via VGA, I've used it many times via my X-Select D4 (not currently part of the setup, getting recapped).

Looks like I have newer firmware: 2.02-6.7-2.91

Some of my aspect ratio options are different than what you described: http://imgur.com/a/zZ5rh
Extron readings with your (approximate) settings: H 16.22k V 59.9Hz

No luck yet.

[Fudoh]

@Blair:

the RGB interface should also help as a sync combiner, all my CRTs needed it to display a stable image. that might also be part of your issue.

you can set the iScan's RGB output to composite sync and remove the V-Sync connection completely. This way you can see if the chain behaves differently with the interface removed.

@SGGG2: The XGB-3 is not exactly the benchmark in connecting off-spec 15khz signals. What's your point eventually ?

[SGGG2]

Just want to scanline some Dreamcast games. Don't feel like tracking down an Emotia (I actually have one that's not powering up).

[Blair]

I have newer firmware: 2.02-6.7-2.91, some of my aspect ratio options are different than what you described

That's good to know, the principal should still pretty much work the same. [Active input AR] should be set to 1.33:1 (with the rest of my settings being still applicable).

Extron readings with your (approximate) settings: H 16.22k V 59.9Hz

How are you connecting the RGB interface to the XRGB? Are you using an RGBHV cable?

My tests indicate that it has to be from the Extron's BNC outputs, the "monitor-out" D-sub 15 doesn't work for combining sync when connecting to my CRT's

Also, do you have DDSP: on or off?

you can set the iScan's RGB output to composite sync and remove the V-Sync connection completely. This way you can see if the chain behaves differently with the interface removed.

I tried that with the 14m2u, it wouldn't display a stable image. I had to connect it to the 203vtg. All of my current RGB/VGA testing indicates that the Extron RGB interface is required for these current settings.

I'm going to try outputting component YPbPr directly from the HD+ into the CRT's and see if that changes anything. (I have the official DVDO component breakout cable).


(edit)

reading more about the XRGB3, it seems that it can actually output 320x240 on its own. has anyone tried 480p into an XRGB3, outputting at 320x240 into another XRGB3? (that should enable its scan-line engine).

has anyone tried connecting an XRGB3 outputting 320x240 to a CRT? (PVM?)

[Fudoh]

Just want to scanline some Dreamcast games

Add a SLG unit to the DC's VGA output. Much easier.

[BuckoA51]

reading more about the XRGB3, it seems that it can actually output 320x240 on its own. has anyone tried 480p into an XRGB3, outputting at 320x240 into another XRGB3? (that should enable its scan-line engine).

That's madness, just get a SLG3000 or similar. I think Fudoh tried the downscaling on the XRGB3 and said it was pretty poor?

[Fudoh]

I think Fudoh tried the downscaling on the XRGB3 and said it was pretty poor?

it's poor yes, but it wasn't me. Somebody with a cab - can't remember who.

[Blair]

That's madness, just get a SLG3000 or similar. I think Fudoh tried the downscaling on the XRGB3 and said it was pretty poor?

madness?

Spoiler

this is Sparta!

I agree that using an SLG might be an easier way of getting scanlines, but I'm assuming he wants to use the XRGB3 because the scanlines it can produce are much darker and sometimes more pleasing then what an SLG can achieve on its own.

it's poor yes, but it wasn't me. Somebody with a cab - can't remember who

that's interesting, I'd like to see the thread if anyone can remember the name of it. was it a very in-depth test of the downscaling ability?

because if he wasn't using properly divisible resolutions, that might've been why it looked bad. (same thing with my current testing of the DVDO units, if you're even just one pixel off with your calculation they can look terrible).

Have you tried 1280x240 instead of 720x240?

I've tried both 1440x240 and 1280x240 on the VP50 and it looks really nice.

No, sorry, you need to go VGA to component first.

actually I just realized something, after reading through some specs on the HD+ it says that the video inputs on the back can handle RGBs as well as component (YPbPr)

using a BNC4 cable with combined sync, or a BNC5 cable (and just combining sync with a Y-adapter) sounds like a better idea than transcoding VGA to component. like we're doing right now.

(I've noticed that the DVDO units can be a little finicky with transcoder's)

it would simplify the video chain, and take out another point of failure. (I'm going to try that when my next batch of BNC converter Jacks arrive)

[BuckoA51]

I agree that using an SLG might be an easier way of getting scanlines, but I'm assuming he wants to use the XRGB3 because the scanlines it can produce are much darker and sometimes more pleasing then what an SLG can achieve on its own.

They're really not, plus SLG3000 has an adjustable pot that can darken/lighten them to taste.

[Fudoh]

actually I just realized something, after reading through some specs on the HD+ it says that the video inputs on the back can handle RGBs as well as component (YPbPr)

yes, but RGBs on these inputs was meant for European DVD players, so 15khz. You have to try to find out if they can accept RGBs in 31khz as well.

[Fudoh]

scanlines it can produce are much darker and sometimes more pleasing then what an SLG can achieve on its own.

I never noticed this, but I think it can depend on the display. After all SLG emulation on a VGA signal is trickery at best. The signal level simply get decreased on every other line. If a display tries to compensate for this, it's possible that the brightness on the darkened lines gets visibly increased.

Let's not forget that I've seen machines completely eliminating the scanline effect from a MiniSLG or SLG3000.

[SGGG2]

To be honest, I didn't think it would be this complicated.

I have an SLG3000 already but one of the pots is bad, and I'm hesitant to buy another one. I wanted a dedicated downscaler -- Emotia's are really hard to find (and not cheap either), and it's probably useless, but I find the possibility of downscaling 720p content novel. I have a RGBs cable, just need some BNC adapters.

[Blair]

They're really not, plus SLG3000 has an adjustable pot that can darken/lighten them to taste.

I don't have an SLG 3000, but I do have a clone (probably based off t-slg) and even adjusting the pots to their maximum value still leaves noticeable gray lines. I've read a few other users complaining about the same problem with the SLG 3000.

it also probably depends on how far you can push the contrast ratio of your monitor.

yes, but RGBs on these inputs was meant for European DVD players, so 15khz. You have to try to find out if they can accept RGBs in 31khz as well.

that's interesting, it doesn't say anything about that in the literature I have. i'll keep digging.

thanks for the heads up.



on a side note, why would DVD players have a 15 kHz output? (aren't all DVDs 480i or 480p?)

my super VHS has a 240p output, but that's only for the setup menus. the actual content still plays out in 480i.

[Blair]

I have a RGBs cable, just need some BNC adapters.

you need to make sure that H-sync and V-sync are combined on the sync cable (I've read that a lot of RGBs cables just have H-sync)

it still might work but I'm not sure.

[Fudoh]

on a side note, why would DVD players have a 15 kHz output? (aren't all DVDs 480i or 480p?)

DVD is D1. That's classic NTSC/PAL, so 15khz in 480i for NTSC and 576i for NTSC. 480p from a DVD Player is always running through an internal linedoubling device, although it's possible to get native 480p from a DVD by working around the MPEG decoder, but that's not within the official specs.

[Blair]

that makes sense.

part of the feature list, says it can process above 480p on those inputs. but of course it doesn't really specify which connection standard its talking about. (I'll look through the service manual later)

[Fudoh]

you don't have to quote the specs. I know these machines. Still I can guarantee you that DVDO never tried any 31khz RGBs source, so you really gotta try it to be sure.

[Blair]

I never noticed this, but I think it can depend on the display. After all SLG emulation on a VGA signal is trickery at best.

(240p)

(slg)

(images best viewed if you take a step back from your monitor)

I took some pictures to help illustrate (both from my PVM-20L5), real scan-lines on my display are pure black, while the SLG produces gray contrast lines. it definitely makes graphics sharper ( especially games that were meant to be in 240p) but it doesn't have nearly the same effect as a real 240p signal.

I've seen videos of the XRGB scan-line effect and it gets remarkably close to pure black scanlines. (they probably are pure black on a CRT display). it looks much more realistic then any SLG I've ever seen.

it seems to me that xrgb3 produces superior scan-lines. (of course a real 240p signal on a CRT is probably best)
I know everybody has different personal preferences, not everybody likes pure black scan-lines (pure black is my preference).

but you see what I mean now, right?

(I also tested the SLG on the Sony E400 CRT, and the Asus VW 246H LCD, same result of gray lines no matter how high I push the contrast ratio)

*edit*

with the help of Fudoh, I was able to figure out why the SLG produced gray lines instead of the proper dark ones. it turns out that the analog output from (some) DVDO units is a little bit intense for an SLG to handle on its own, while connecting an SLG to the VGA output of a standard video card or a GBS-8200 works just fine. to mitigate this problem you have to put an Extron RGB interface (with level and peak controls) between the DVDO and the SLG. this allows you to adjust the video level manually to get the proper dark scanlines from an SLG when hooked up to the DVDO units.

thanks to Fudoh for helping me figure this out, here's a winning combination I use (if you don't want to do downscaling).

Video chain: Coaxial RGB Scart -> VP50pro ->RGB203 rxi vtg ->SLG (100% intensity) ->PC CRT (or any other monitor capable of displaying VGA/480p resolutions).

[Blair]

To be honest, I didn't think it would be this complicated.

for some reason, trying to get decent scanlines always adds more complexity to anything,

I think this method of downscaling also probably lends itself better to being displayed on a professional grade CRT, because they're a little more lenient with signals then digital devices. but then again I've never really used any of micomsoft products.

instead of using my timings (that have only proven to work on PVMs)

have you looked at these?


modline generator http://xtiming.sourceforge.net/cgi-bin/xtiming.pl

modline calculator http://www.epanorama.net/faq/vga2rgb/calc.html

the calculator has some prefab settings you might want to try.

I wanted a dedicated downscaler -- Emotia's are really hard to find (and not cheap either), and it's probably useless, but I find the possibility of downscaling 720p content novel. I have a RGBs cable, just need some BNC adapters.

I know how you feel, I think even some high-resolution content can be vastly improved by scanlines. (tons of Indy shooters, and retro style games like shovel night... I also like watching 80s movies in 240p. for some reason it just feels right, especially for Tron)

[Xyga]

Indeed all XRGB's that do fake scanlines internally produce black lines, when the SLG's own lines are grey whatever the strength.

[BuckoA51]

I still have a hard time believing that downscaling a signal and then linedoubling it again will make for better results than a simple SLG.

[Blair]

well, it's essentially because he's having to work around limitations of the XRGB3

I don't understand why they didn't allow scanlines to be enabled on 480i or 480p sources.