DVI Extender color issues

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Brandon Tan

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DVI Extender color issues

PostTue Oct 21, 2014 2:15 pm

I connected a Barco Imagepro DVI output (1920x1080@30) to the BMD DVI extender then to a SDI input of 12x12 Smart Videohub. Sent out a color bar and to my surprise the colors are different. The colorspace for the Barco output is RGB.

SMPTE color bar: gray, yellow, cyan, green, magenta, red, blue

What i got: gray, cyan, yellow, green, magenta, blue, red

please help me explain why the cyan, yellow, red and blue are in different order?
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Chad

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Re: DVI Extender color issues

PostTue Oct 21, 2014 7:59 pm

The DVI extender only supports YUV color space, not RGB when in video mode. Though you can switch it to "extender" mode which causes it to output a proprietary signal over the SDI cable that can only be read by the HDLink Pro or newer. That mode should support an RGB signal.
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Brandon Tan

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Re: DVI Extender color issues

PostWed Oct 22, 2014 3:36 am

Hi Chad,

So can I say that if i connect device to BMD DVI extender (extender mode) then to HDlink, can I output RGB colorspace from the HDLink's SDI output or the DVI output?

I dont understand how the DVI input of the BMD DVI extender will support YUV colorspace when most DVI devices are sending RGB colorspace. THe extenders work for me only when i send a HDMI to DVI source from a laptop and the color is correct.
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Chad

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Re: DVI Extender color issues

PostWed Oct 22, 2014 10:34 pm

1. Yes. That is the purpose of the HDLink box.

2. It's because HDMI supports both RGB and YUV (as do consumer TV's), while SDI only uses YUV color. The DVI extender (and any other HDMI/DVI device) sends a signal to the connected computer telling it what resolutions / formats it supports (called EDID) and if the graphics card is capable, it will send out a compatible signal.
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Tom_Bassford

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Re: DVI Extender color issues

PostThu Oct 23, 2014 8:19 am

You can adjust the colourspace on the image pro to be YUV (actually it is YCrCb but everyone says YUV) then your colours will be correct.



Cheers
Tom

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Brandon Tan

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Re: DVI Extender color issues

PostFri Oct 24, 2014 8:35 am

Hi Chad,

WIll i be able to send 1920x1080p@60 source to DVI extender then to HDlink Optical fiber then to DVI input of a projector?
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Brandon Tan

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Re: DVI Extender color issues

PostFri Oct 24, 2014 8:38 am

Tom_Bassford wrote:You can adjust the colourspace on the image pro to be YUV (actually it is YCrCb but everyone says YUV) then your colours will be correct.



Cheers
Tom

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Hi Tom,

From imageproHD DVI output to DVI extender, in YCrCb colorspace, i will get magenta colored background. In RGB colorspace i will get the correct colors except the colors are inverted. Yellow with Cyan. Red with blue.
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Tom_Bassford

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Re: DVI Extender color issues

PostFri Oct 24, 2014 5:48 pm

Your DVI extender is faulty then.

Just use the SDI out of the ImagePro.
http://www.atemuser.com
if it was easy it wouldn't be called engineering

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