Yes, it is possible. HDMI is - electronically speaking - a descendant of DVI-D, so it will work fine, unless there's some weird initialization quirk in the card's firmware. Early HDMI ports on GPUs were basically just a DVI-HDMI adapter built into the card itself or an actual adapter and that continues to this day, though DVI was replaced with DisplayPort, which incorporates the HDCP required for HDMI use in Windows.

RetroGamer4Ever wrote on 2022-05-25, 16:22:

Yes, it is possible. HDMI is - electronically speaking - a descendant of DVI-D, so it will work fine, unless there's some weird initialization quirk in the card's firmware. Early HDMI ports on GPUs were basically just a DVI-HDMI adapter built into the card itself or an actual adapter and that continues to this day, though DVI was replaced with DisplayPort, which incorporates the HDCP required for HDMI use in Windows.

Hrm, does that imply that the output quality also comes with the same issues as a cheap DVI->HDMI conversion?
I mean I guess at least it should hopefully not have troubles with displaying 70hz as some cheap converters. Or will it just show blank then?

It is a NATIVE HDMI card, which means it has an HDMI port on the card in place of a DVI or DisplayPort output. The GPU itself has two digital A/V outputs intended for DVI-D use and one of those is (usually) converted to HDMI or DisplayPort, depending on the choice of the card designer. Because HDMI and DisplayPort are signal-compatible with DVI-D, a simple physical conversion is all you need to replace one with the other.

RetroGamer4Ever wrote on 2022-05-25, 17:24:

It is a NATIVE HDMI card, which means it has an HDMI port on the card in place of a DVI or DisplayPort output. The GPU itself has two digital A/V outputs intended for DVI-D use and one of those is (usually) converted to HDMI or DisplayPort, depending on the choice of the card designer. Because HDMI and DisplayPort are signal-compatible with DVI-D, a simple physical conversion is all you need to replace one with the other.

I am not sure what the implications are.
The usual problem is: VGA Out, cheap converter converts that to HDMI, capture card fails as it cant handle 70Hz.

Does that mean that these graphics cards just output this HDMI signal as 70Hz as well, which also means that capture cards will fail?

Get a graphics card with a DVI output and use a passive adapter

keenmaster486 wrote on 2022-05-25, 17:37:

Get a graphics card with a DVI output and use a passive adapter

Hrm, I got one DVI card lying around, and got 2 passive adapters. I will test this. My impression was that VGA and DVI could just be converted to each other.
But the issue is that HDMI always fails with the 70Hz.

Will test this now, but somewhat doubt it'll work.

The video card will output whatever signal it outputs, from the GPU, as controlled by the software you are running and the firmware of the GPU. In order to use 70hz, the GPU has to be set to output 70hz and you need an HDMI cable that can handle a 70hz signal. For video capture, you need a capture device that also supports 70hz, otherwise, you stick with 60hz.

RetroGamer4Ever wrote on 2022-05-25, 17:45:

The video card will output whatever signal it outputs, from the GPU, as controlled by the software you are running and the firmware of the GPU. In order to use 70hz, the GPU has to be set to output 70hz and you need an HDMI cable that can handle a 70hz signal. For video capture, you need a capture device that also supports 70hz, otherwise, you stick with 60hz.

Yep, ok. Also just tested the other card with DVI->HDMI via passive adapter but as expected, capture card cant handle it. So unfortunately its back to square one. Unfortunately most HDMI capture devices cant go beyond 60Hz. I got two which don't work.

But in case I had one which did work: Is there any advantage/disadvantage from capturing hdmi over a VGA signal?
I mean this datapath visionrgb is over 1000€, so why wouldn't you just convert it to dvi and then to hdmi and capture that if its the same?

There are several cards that are in the VisionRGB line, so I can't say anything more than that, without knowing exactly what you have.

RetroGamer4Ever wrote on 2022-05-25, 18:22:

There are several cards that are in the VisionRGB line, so I can't say anything more than that, without knowing exactly what you have.

Afaik there is just two cards. VisionRGB E1s and E2s but they are essentially the same besides of having 2 or 1 input. They go for 1.239,00€ new or about 300€+ used.
But my question was just about why bother with it, if you could passively convert vga to hdmi and then capture it (if the capture device manages more than 60Hz).

I just need a way to capture a vga signal. I got the stuff to passively convert it to dvi and to convert dvi to hdmi. I also have 2 converters (passive) to convert VGA to hdmi.
I also have two capture cards which dont do more than 60Hz (elgato)

I use VGA to HDMI active adapter, because DVI/HDMI out on GPUs... is iffy with DOS.
As plan B, I have DVI to DP, and then DP to HDMI 😀 (works out much better than passive DVI to HDMI in my case).
As plan C I use a seperate VGA to DVI active adapter in combination with DVI to DP + DP to HDMI.

Upscale to 1080p 60Hz on adapter does "good enough job", for my really strict capture card to show image on DOS.
Also, with ATI cards you will need to install CCC to get rid of underscaling image on DVI/HDMI to HDMI capture input.

Re: VGA Capture Thread

The second image is from a video recorded from a PCI Voodoo3 outputting standard VGA text mode in real mode DOS .

This should work the same way for any VGA card in a PC running any version of DOS.

EDIT : Most DVI capable cards upscale their output, including DOS text mode . This can be manipulated, to a point, using an EDID emulator and/or patching the video card's BIOS . Re: 70Hz in pure DOS at 1600x1200 (or other) over DVI on an old card (FX5900) with modern monitor is possible

I am not quite sure what the OSSC implies (usually you would use it to bring it into a fitting resolution). But without OSSC, the Camlink 4k isn't doing anything if connected to a passive vga->hdmi converter unless its at 60Hz

Just did a few tests. Values are what is displayed by the monitor / visible in setup, decimal places in refresh rate are rounded.
DOS: 720x400 70hz does not work

with Duke Nukem 3D:
320x200 does not work. Monitor displays that its changed to 720x400, and it runs on 70Hz
VESA 320x200 does not work. Monitor displays that its changed to 720x400, and it runs on 70Hz
VESA 640x480 does work -> 60Hz
VESA 800x600 does work -> 60Hz

For all I know, a passive VGA -> DVI or HDMI convertor does not exist.

Kordanor, what is this passive vga->hdmi converter you are talking about ? photo, brand/model/type...

weedeewee wrote on 2022-05-26, 10:45:

For all I know, a passive VGA -> DVI or HDMI convertor does not exist.

Kordanor, what is this passive vga->hdmi converter you are talking about ? photo, brand/model/type...

Sure. Maybe they aren't all strictly passive. Not sure what the definition is.
The test mentioned above has been done by the one which is most likely considered as active with the USB for additional power. This one:

This one I only tested once before.

And lastly here is the DVI->HDMI Converter

I'm running a Matrox G450 with native DVI output in a 486. This card uses a PCI to AGP bridge chip.

However, since almost all 486 boards with Award 4.50 / 4.51 BIOS will not initialize the graphics chip because in the boot process PCI bridges are just initialised too late.
My 486 in a Shuttle HOT-433 seems to be an unicorn because mkarcher has developed a patch for the BIOS to initialize the bridge earlier.

My 486 UMC8886/8881 Project (Version 2.0)
Matrox G450 (with DVI outout) working on a HOT433 main board (UMC 8881)

Kordanor wrote on 2022-05-26, 11:00:

Sure. Maybe they aren't all strictly passive. Not sure what the definition is.
The test mentioned above has been done by the one which is most likely considered as active with the USB for additional power. This one:
vga-hdmi.JPG

active, VGA to HDMI .

This one I only tested once before.
vga-hdmi2.JPG

active, looks like a HDMI to VGA adapter

And lastly here is the DVI->HDMI Converter
dvi-hdmi.png

likely passive

boils down to this,
active means it has integrated circuits inside,
passive means it's just wires, maybe some resistors, capacitors and/or inductors.

Kordanor wrote on 2022-05-26, 11:00:

This one I only tested once before.
vga-hdmi2.JPG

If i'm reading that correctly, it's not vga-hdmi, but hdmi-vga. HDMI is the source, VGA is the output. AFAIK, HDMI can produce VGA signals. It does not work the other way around.

GigAHerZ wrote on 2022-05-26, 13:37:

If i'm reading that correctly, it's not vga-hdmi, but hdmi-vga. HDMI is the source, VGA is the output. AFAIK, HDMI can produce VGA signals. It does not work the other way around.

since HDMI = digital, and VGA = analog and there's more differences wrt the actual signals,
HDMI can NOT produce VGA signals
One should however be able to get VGA resolutions on HDMI, as in 640x480@70Hz, Though, support for displaying these will depend on the monitor or adapters being used.

To hook up an analog VGA monitor to a HDMI output of a graphics card you will always need an active adapter.