Amstrad RGB (scart) to Component (YPbPr), how?

[emuola]

I was asked to provide retro computer(s) to a Twitch stream run by university students. The problem is, the "usb video grabber" only has the following inputs: compos(h)ite, Component  (YPbPr) and hdmi. I really don't want to use compos(h)ite, because it sucks. How could I easily? hook up the 6128+ with a rgb scart cable to the component inputs of the grabber? It seems it could be done, but what would you guys suggest? I'd really would not like to spend too much money on this because this might be the only time something like this is gonna happen.


Thx!

[Bryce]

I'm not aware of any hardware that converts RGB to YPbPr, or at least none that won't cost you a fortune and has been tested with the CPC. The cheapest way would be to buy a video grabber with S-Video and get an RGB to S-Video adapter, or buy a RGB to HDMI converter which might cost a bit more.

Bryce.

[emuola]

I'm not aware of any hardware that converts RGB to YPbPr, or at least none that won't cost you a fortune and has been tested with the CPC. The cheapest way would be to buy a video grabber with S-Video and get an RGB to S-Video adapter, or buy a RGB to HDMI converter which might cost a bit more.

Bryce.

Ok, thanks Bryce I just realised that as I have XRGB-mini Framemeister with scart-adapter cable, I can use just that How stupid of me not thinking straight 

[chinnyhill10]

I was asked to provide retro computer(s) to a Twitch stream run by university students. The problem is, the "usb video grabber" only has the following inputs: compos(h)ite, Component  (YPbPr) and hdmi. I really don't want to use compos(h)ite, because it sucks. How could I easily? hook up the 6128+ with a rgb scart cable to the component inputs of the grabber? It seems it could be done, but what would you guys suggest? I'd really would not like to spend too much money on this because this might be the only time something like this is gonna happen.


Thx!

Find a good quality DVD recorder. You'll be able to input RGB and output component live. This is exactly how ChinnyVision is captured. Although I am afraid it is trial and error what models of DVD recorder can do this well. Pioneers are good but hate the CPC signal for example. I have ended up buying 4 DVD recorders and currently use a Pioneer for most things and a Panasonic for some other machines (CPC included). A good recorder will also deinterlace for you and will let you tweak the picture and turn the AGC and noise reduction off (my Pioneer does).

[TotO]

My Scart to HDMI converter cost around 35$ and work fine.
It look like that. (not sure that I have the HDMI input on mine)

[chinnyhill10]

My Scart to HDMI converter cost around 35$ and work fine.
It look like that. (not sure that I have the HDMI input on mine)

I have one of those. Total rubbish best avoided unless you like an oversaturated, over sharpened image with a processing delay that renders many fast games unplayable.


Hang on, I need to sell mine........ er, they are great. Anyone want to buy one?

[TotO]

I use it with CPC, Megadrive, Saturn, CD32, ... Absolutly no problem like you describe.

[chinnyhill10]

I use it with CPC, Megadrive, Saturn, CD32, ... Absolutly no problem like you describe.

Perhaps you have a "good" unit. But others I've spoken to report exactly the same issues as I've found.

[TotO]

It is sade so...
My friend iXien own the same and no problem too. (bought 2 weeks after mine, 2 years ago)

[chinnyhill10]

It is sade so...
My friend iXien own the same and no problem too. (bought 2 weeks after mine, 2 years ago)

Perhaps I'm just over sensitive to a blurry image when moving and massive sharpening kicking in when the screen stops moving...... Fast moving 50fps scrolling games like Plok on the SNES looked horrible.

[gerald]

I use it with CPC, Megadrive, Saturn, CD32, ... Absolutly no problem like you describe.

How does it handle relentless scrolling ?

[chinnyhill10]

How does it handle relentless scrolling ?

Blurs all the time. It just looks soft until you hit pause or stop when it suddenly looks over sharpened. Very unimpressed with it. There are no internal pots to control the sharpening or saturation either. The Pioneer and Panasonic DVD recorders do a far better job. The Pioneer especially enables you to tweak very part of the signal including noise reduction, the deinterlacing, black levels, white levels, saturation and number of other parameters.

[TotO]

How does it handle relentless scrolling ?

Shaking on one DLP retroprojector.
Perfect on the Toshiba TV. (but, only during 5 seconds, then it display a blue screen with a sync signal problem message)
It cleary look that limitation is only related to the TV electronic "thinking" the signal is bad, but it is visually not. 

[TotO]

Perhaps I'm just over sensitive to a blurry image when moving and massive sharpening kicking in when the screen stops moving...... Fast moving 50fps scrolling games like Plok on the SNES looked horrible.

Sorry, but all 50/60Hz moves look perfect. You are not a bionic[nb]I see DLP rainbow problems, I am one?  [/nb] man. 

[SOS]

Sorry, but all 50/60Hz moves look perfect.

Hmm, this can't be the gift of the converter. The signal must be converted from 50fps to 60fps - a converter for 35$? A more expensive converter (framemeister) has problems with that.
Let me talk about your Toshiba-TV - does it support native 50HZ signals?

(ooops i promised some times ago  , to post a scrolling-demo-video on youtube with the framemeister -  ok, in one month i have vacation)

[TotO]

Hmm, this can't be the gift of the converter. The signal must be converted from 50fps to 60fps - a converter for 35$? A more expensive converter (framemeister) has problems with that. Let me talk about your Toshiba-TV - does it support native 50HZ signals?

The converter handle 50 and 60Hz. The TV handle 50 and 60Hz.
The TV is a Toshiba Regza series for the french market.

[Velktron]

Compared to YUV or YC, YCbCr is relatively easy to obtain from RGB signals because there are as many outputs as there are inputs, and there are no complex operations like multiplexing/heterodyning: if you can tolerate some color/luminosity imprecision, you can build a completely passive analog RGB to YCbCr converter that's also completely agnostic of the resolution or scan rates that you're using.


Check out the formulas:


YCbCr - Wikipedia, the free encyclopedia


Those can be implemented with a passive resistor network, if some signal loss or impedance mismatch is acceptable. Of course, you can add buffer circuits to enhance those characteristics, or use  a special IC like the SGM9116 video filter.


Also, in Analog Circuit Design Volume 2: Immersion in the Black Art of Analog Design
, there's a schematic for an active RGB/YPbPr converter that uses opamps to keep signal handling characteristics stable:


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