HDTV Forum

My 5 year old Samsung 56" DLP has one DVI input. My D*TV DVR, and the Toshiba A-2 HD-DVD Player as well as the Samsung BP1400 Blu-ray all use HDMI out for best performance, of course. I am having issues with conversion of HDMI to DVI. Has anyone found a device that converts the video signal properly across various devices? I had an old Gefen 2x1 that worked reasonably well, but now I need 3 HDMI inputs and maybe more down the road.

You could upgrade your receiver to one with 3 HDMI inputs, then use the HDMI-DVI converter on the monitor feed.

Thank you. To solve the multiple input issue, I have actually tried a couple of switchers combined with a converter. Octavia and Psyclone switchers have not worked well. Hope to year of someone with actual experience with a specific product or set up that works well to switch as well as convert.

You are treading down the wrong path...

The conversion problem is from the source. HDMI puts us in a native YPbPr digital component world and that is what manufacturers design and test for. Conversion to digital DVI RGB video is a second thought with the only requirement being that it work and that does not mean it will work right, just that you get pictures. The type and amount of error will vary from product to product so it requires more than a one size fits all solution.

The only way to fix your problem is replace the display with current HDMI enabled product or put a Lumagen external scaler in the signal chain which has all the tools to fix such errors provided you have the knowledge and equipment to adjust them and it will have to be done for every DVI source. You are in ISF calibrator territory...

ISF and HAA - The Expression of Art using Science
viewtopic.php?t=4450

http://www.lumagen.com/

Another potential method is an HD Fury...
viewtopic.php?t=8497
... which will keep your HDMI in YPbPr format and convert to RGB but the output is VGA. If your display has a VGA input you would need to test or find out if it will provide the same HD support you get with the other inputs on the display.

If you don't have a VGA then you would need to convert the output of the Fury back to YPbPr or back to digital DVI RGB.

For my clients we would go with either replacing the display or the scaler only if they are seeking HD audio codecs from either of the HD disc formats. If not, the easy, inexpensive and viable performance solution is use component since it's not like you can use the 1080p60 or 1080p24 capability anyway.

Thank you, Richard. This gives me insight into the causes and possible solutions.

Thanks again.

Situations like this are so complex...

If you need the HDCP of DVI/HDMI for HD audio another solution is to calibrate the settings for that input. Can't tell you if both players will match up though... then you would need different settings for each player.

A calibration disc for HD DVD...
http://www.hdtvmagazine.com/hdstore/pro ... 104&page=1

HDMI is backwards compatible with DVI - so all you need is a passive HDMI-to-DVI cable. This also means that you can drive the DVI input of your display from a 3-to-1 switch with HDMI ins and outs (i.e. you don't need a switch with a DVI output). Again, you just need to use the right cable.

HDMI follows the CEA-861 standard, which requires all devices to support RGB color space, by default. Note that DVI only supports RGB, because there is no reverse (InfoFrame) channel to announce a change in color space (e.g. from RGB to YCbCr). YCbCr is optional (according to CEA-861) and must be negotiated for by handshake. So if YCbCr is not supported by the display, then the HDMI source will automatically default to RGB. HDMI sources must look at the display's EDID and, if an HDMI Vendor Specific Data Block is not found, are obliged to provide RGB space.

As far as audio goes, an HDMI AVR with 3-to-1 switch would make things easy. You could also split-off the audio and mix/switch the analog or SPDIF output of the sources using a no-video audio amplifier, but that would be more difficult to control.

HDMI follows the CEA-861 standard, which requires all devices to support RGB color space, by default.

It works and is supported. There is nothing beyond that requiring a manufacturer to align or calibrate that output to video standards except for pride in their own products, money to pay someone to do that and a market that cares about such things.

The lack of standards and/or willingness to follow them has been horrid for decades in both video and audio...