Author Topic: RGB to HDMI?  (Read 459 times)

grahf

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RGB to HDMI?
« on: February 14, 2011, 03:31:22 AM »
Unfortunately the only TV I have access to over here is a plasma, with a terrible comb filter. It also has some weird noise reduction (I think) that makes the pixels flutter behind moving sprites. Uggg... I figured there was no point in s-video modding my new setup because my Super Famicom looks just as shitty with s-video. I figured i'd give one of those SCART to HDMI converters a try, and see how it looks hooked up to my PC monitor. I've seen some screenshots from the Megadrive forums, and they aren't too bad.
It's GOT to look better than the plasma, in any case.  :lol:

I went with a quick mini-din-8 mod (the one on mmmonkey's site). I also threw together an SCART cable with the 3-transistor amp inside the shell.
This is the converter I went with:
http://www.hdcable.co.uk/scart-hdmi-converter.html









SuperDeadite

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Re: RGB to HDMI?
« Reply #1 on: February 14, 2011, 03:36:58 AM »
Just pick up an XRGB.  They show up in Hard-Offs and the like for cheap.  I found a boxed XRGB-1 for 2,000yen. 
Wonderful device.
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Black Tiger

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Re: RGB to HDMI?
« Reply #2 on: February 14, 2011, 03:49:32 AM »
I bought an rgb modded Duo from that japanese eBay seller as well as a scart to hdmi converter. Unfortunately, I can't get a proper signal using either the hdmi converter or the scart to component converter I also bought. :(

The thing is, both converters work with my Sega and Neo Geo systems. The seller said that I'm pretty much SOL and that it must be the converters.

The image quality of the hdmi upscaler looks kinda like composite output from a classic console on a crt. The clarity and maybe even color looks nicer using only compisite or s-video on my 1080p lcd, but the upscaler eliminates the TV's filter that smoothes out all the jaggies and dithering.

I would prefer the upscaler's image, except that it doesn't send a 4:3 flag or whatever and my TV won't let me chose the perspective. So I basically gave up on ever playing on the lcd. :P
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grahf

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Re: RGB to HDMI?
« Reply #3 on: February 14, 2011, 12:04:20 PM »
Super Deadite, I forgot to mention it but my PC monitor is a 1080p LCD panel and only supports DVI/HDMI input. Doesn't that limit my choices to only the newest XRGB-3? That one is still a bit pricey.

Black Tiger, I hope the one I picked up works. I know that the csync might need some tweaking to work on SCART tvs, so maybe I'll have to do some playing around with it. You've got me worried about the aspect ratio though. I know some upconverters respect it, so I hope the one I got does.

Duo_R

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Re: RGB to HDMI?
« Reply #4 on: February 14, 2011, 12:30:44 PM »
i got a new receiver that upconverts component to HDMI. So tonight I am going to try out RGB > Component > HDMI

and see how that works on the LCD.
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kid_rondeau

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Re: RGB to HDMI?
« Reply #5 on: February 14, 2011, 12:44:43 PM »
The things you guys are capable of....it never ceases to amaze me. I'm really proud to be part of these forums.

Duo_R

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Re: RGB to HDMI?
« Reply #6 on: February 14, 2011, 12:47:15 PM »
Grahf haven't seen you on the boards for a while, glad to see you are still around. Looking forward to what you post.
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SuperDeadite

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Re: RGB to HDMI?
« Reply #7 on: February 14, 2011, 01:41:32 PM »
Yes that limits you to the 3 B0 mode (which sucks for games).  :(  Personally I'd recommend just getting
a nice 20'' Sony CRT from Hard-Off instead.  They accept pure RGB input, and look fantastic. :)
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Black Tiger

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Re: RGB to HDMI?
« Reply #8 on: February 14, 2011, 02:51:31 PM »
Just tried it out again. Set the TV to display "Dot by dot". The hdmi converter outputs 1080p. I then hooked up the Genesis using S-Video through an XMD-3 and then a Duo composite cable.

From top to bottom these pics are-

HDMI
S-VIDEO
COMPOSITE












It really looks like the scart RGB to hdmi converter is just taking a composite signal and upscaling it and removing the 4:3 flag. The jaggies are the clearest for low color sections like the mountains and clouds. Otherwise it's pretty much a sharper version of composite (with various distortions and all).

The S-Video image looks perfect, the way I expect RGB to appear. It also defaults to 4:3. But my TV's filter has smoothed things out a bit and I don't like that stuff. Again, check out the mountains and clouds where the jaggies should be.

The composite image also appears at first to have better color and less noise than the hdmi signal. But it has some of the same distortions and has the TV filtering a blurry picture. Still defaults to 4:3 though.


If I had to play a 240p console on this TV, I'd just go with s-video. It was worth experimenting though, since the hdmi converter only cost like $60 shipped. I won't bother posting a photo of the hdmi converter itself, since it looks different than the art on the box, which matched the one that the japanese PCE RGB modder uses.
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Duo_R

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Re: RGB to HDMI?
« Reply #9 on: February 14, 2011, 03:17:05 PM »
S-video isn't being supported as much anymore as most TVs don't have that input anymore. So another solution must be found.
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Black Tiger

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Re: RGB to HDMI?
« Reply #10 on: February 14, 2011, 03:24:55 PM »
S-video isn't being supported as much anymore as most TVs don't have that input anymore. So another solution must be found.

For me HDTVs aren't a solution. I'll only use them in extreme circumstances. It was actually very hard for me to find a decent CRT that accepts component (I inherited it from my brother) and S-Video is still the only way to go for non-professional capture cards.
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grahf

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Re: RGB to HDMI?
« Reply #11 on: February 14, 2011, 03:34:35 PM »
Black Tiger, the second and third pictures look like I would expect. That first picture looks strange.

The first picture is pure RGB fed directly into an HDMI upscaler, correct?
The upscaling process itself looks OK (besides the aspect ratio), with nicely defined pixels. It looks like the pixels themselves have noise in them. It could be that the upscaler just does a shitty job at the Analog to Digital conversion, but you might be able to clean up the picture by tweaking the RGB signal. I guess it's all pointless if you can't get 4:3.

Duo_R, yeah I just came back. Feels good to be home :D

SuperDeadite, you're right about a CRT. I just don't have the room for one right now. Or the money. I'll get a nice one after I'm done with my school stuff. In the meantime it's fun to mess with this newfangled HDMI stuff. At least my PC monitor doesn't have any wierd scaling to muck things up like a TV, so i'm hopeful to be able to get a usable picture.

incrediblehark

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Re: RGB to HDMI?
« Reply #12 on: February 14, 2011, 04:01:21 PM »
I bought an rgb modded Duo from that japanese eBay seller as well as a scart to hdmi converter. Unfortunately, I can't get a proper signal using either the hdmi converter or the scart to component converter I also bought. :(


japanese rgb and scart are are wired differently. you need to rewire the pins on your rgb cable to match euro scart standard then your converters will work with the duo you bought. Its actually pretty easy, here is a link to the different pinouts:

http://www.mmmonkey.co.uk/console/other/jrgb.htm

if you dont want to mess with the duo's rgb cable you can buy a female to male scart connector cable and rewire the female end to japanese rgb and it will act as a converter.

SignOfZeta

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Re: RGB to HDMI?
« Reply #13 on: February 15, 2011, 02:41:24 AM »
Just tried it out again. Set the TV to display "Dot by dot". The hdmi converter outputs 1080p. I then hooked up the Genesis using S-Video through an XMD-3 and then a Duo composite cable.

From top to bottom these pics are-

HDMI
S-VIDEO
COMPOSITE


f*cking A. Those pics are hideous.

In all seriousness, unless you have major space issues just buy a 90s tube. A medium to high end late 90s/early 2000s JVC, Sony, Samsung, or Toshiba are going you give you a better picture than ANY flat panel with ANY box hooked up to it and they cost as little as $0. My most recent score was a 27" Sampo/NetTV that I would have killed for 10 years ago (when it was $1300) but now only set me back $20.

If you live in central London (ie: a matchbox) obviously you don't have the space, but for most people, especially Americans, do yourself a favor and leave the LCDs and Plasmas to the newer systems and stop throwing away money on janky little boxes on eBay.

grahf

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Re: RGB to HDMI?
« Reply #14 on: February 15, 2011, 06:23:19 PM »
I'm living in Tokyo, which would definitely qualify me as having "major space issues" :D Plus it's just fun to mess around with this stuff. Sure it'll never be as good as a nice CRT, but It gets the job done.
Some of the boxes on ebay are surely janky, but they aren't as bad as those VGA boxes. I opened mine up and, surprisingly, the construction was quality. I was pretty surprised with my results after what you posted, Black Tiger. My conversion box outputs in either 720p or 1080p, but I couldn't tell any difference between them.

First picture is composite -> HDMI convertor -> Computer LCD panel. 
Second picture is RGB -> HDMI convertor -> Computer LCD panel.

Composite:


RGB (ignore the interference, I didn't have all the grounds hooked up yet)


Just using composite It looks a damn sight better than on my girlfriends plasma TV. The RGB signal is working for me, but it's having problems. I built in the 3-transistor amp into my SCART shell, but the picture looks a bit too bright. I'll try it without the transistors, or perhaps with some 75ohm resistors in-line. Also the picture is really shaky, probably because the composite-sync line does need a transistor. I'll do some tweaking when I have time. I'm probably going to have to just use composite for now, because I forgot something. The CD audio gets mixed inside the interface unit, so my clean mini-din 8 mod is worthless for audio #-o I'll probably just end up tapping RGB/Audio from within the interface unit and putting a plug on that somewhere. I kinda didn't want to mod it though.

Some other thoughts:
Mmmonkey's web site (and a lot of other ones) recommend putting 5v into SCART pin 8, so that's what I did. My  picture ended up at 16:9 like yours, Black Tiger. I checked the SCART specs, and pin 8 is supposed to be:
0v+  for TV select
5v+  for 16:9
12v+ for 4:3
Try disconnecting pin 8 and it may default to 4:3.