Extron vsc + rgb downscaling vs gbs downscaling

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Guile
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Extron vsc + rgb downscaling vs gbs downscaling

Post by Guile »

After trying out the gbs control downscaling I've gotten more interested in the idea. I read the Scanlines Demystified page that mentions using an Extron vsc with an rgb to get 240p.

I have a vsc 500 and an rgb109xi. So if I understand this correctly, I can connect anything to the vsc 500, use a bnc to vga cable to the 480i output, connect the vga 480i to the vga input on the 109xi, hit the ddsp switch, then connect component cables to the 109xi output to a tv with component?

That sounds kind of insane but would that work?

Is there any difference compared to just hooking up the gbs control downscaled output to a tv?
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Unseen
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Re: Extron vsc + rgb downscaling vs gbs downscaling

Post by Unseen »

Guile wrote:That sounds kind of insane but would that work?
No, if you feed the 109xi an RGB signal, it will output an RGB signal. Feeding that to a component input without any further conversion will give you either a black picture or completely wrong colors.
Guile
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Re: Extron vsc + rgb downscaling vs gbs downscaling

Post by Guile »

Unseen wrote:
Guile wrote:That sounds kind of insane but would that work?
No, if you feed the 109xi an RGB signal, it will output an RGB signal. Feeding that to a component input without any further conversion will give you either a black picture or completely wrong colors.
I have a Sony pvm and a consumer tv with component. Right now I'm just plugging in component ypbpr to the 3 RGB bnc inputs on the pvm and it works fine.

On the vsc 500 I connect hdmi or vga to the input and use svideo output. So if I use the RGBHV outputs with a bnc to vga cable, then connect that to the 109xi, I am inputting RGBHV to the 109xi?

At the last step, now I can use bnc cables to connect the RGBHV outputs on the 109xi to the same on the pvm and it should work? I don't have the 109xi at the moment to test.

It's not possible to just plug in the RGB from the 109xi to the component inputs on the consumer tv?

I saw someone comment that these rgb interfaces can output too strong of a signal that could potentially be harmful to a tv, is there any truth to that?
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Fudoh
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Re: Extron vsc + rgb downscaling vs gbs downscaling

Post by Fudoh »

You can set the VSC500 to output component (over three BNC jacks). You can route this through an RGB interface and it will be processed as component and output as component again. So no problems there.

But you have to understand what the RGB interface does. It doesn't downscale, but it it modifies the half line offset on top to make the CRT believe that it receives a 240p signal instead of a 480i one. So the monitor receives the exact same lines per field as it would with 480i, but instead of alternating between odd and even lines to display, it will display the fields on top of each other.

This doesn't work well with every signal.
Guile
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Re: Extron vsc + rgb downscaling vs gbs downscaling

Post by Guile »

Fudoh wrote:You can set the VSC500 to output component (over three BNC jacks). You can route this through an RGB interface and it will be processed as component and output as component again. So no problems there.

So the monitor receives the exact same lines per field as it would with 480i, but instead of alternating between odd and even lines to display, it will display the fields on top of each other.

This doesn't work well with every signal.
Ok, thank you for the explanation. I never had to change the output mode on the vsc so that's convenient to know that I can get component out of it easily.

I was mostly just curious to see what it looks like, I'll give it a try.

Does the rgb interface output a signal that is too strong and could cause damage or problems? I don't want to risk any of my displays just to experiment with this trick.
fernan1234
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Re: Extron vsc + rgb downscaling vs gbs downscaling

Post by fernan1234 »

Guile wrote:Does the rgb interface output a signal that is too strong and could cause damage or problems? I don't want to risk any of my displays just to experiment with this trick.
I don't know if the RGB interfaces simply output what they receive or they always output high level sync, but professional monitors like your PVM will be fine, it is only consumer TVs and some hardware like switches and converters that can be vulnerable.
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Re: Extron vsc + rgb downscaling vs gbs downscaling

Post by Guile »

fernan1234 wrote:
Guile wrote:
I don't know if the RGB interfaces simply output what they receive or they always output high level sync, but professional monitors like your PVM will be fine, it is only consumer TVs and some hardware like switches and converters that can be vulnerable.
Thanks, I'll try it on the pvm then.
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Re: Extron vsc + rgb downscaling vs gbs downscaling

Post by Guile »

I tried this out today, for 480i I noticed very little difference but it was a little smoother and less flickering. I actually couldn't think of many 240p native games that display in 480i to test.

Is there a good one to try this trick on?
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