DuplicateOutput doesn't convert format

Daniel Beneš 1

Hello.
I'm trying to get Desktop Duplication to work on HDR and 10bit displays. But for some reason DuplicateOutput function doesn't convert the output to R8G8B8A8.
If I do

IDXGIOutputDuplicationPtr duplication;   
const DXGI_FORMAT DesktopFormats[] = { DXGI_FORMAT_B8G8R8A8_UNORM };   
const unsigned DesktopFormatsCounts = ARRAYSIZE(DesktopFormats);   
hr = output6->DuplicateOutput1(device, 0, DesktopFormatsCounts, DesktopFormats, &duplication);   
  
DXGI_OUTDUPL_DESC duplDesc;   
duplication->GetDesc(&duplDesc);

And I look into the duplDesc, it say Format = R16G16B16A16_FLOAT (when I have enabled HDR in windows).
But from Remarks here it should convert the format: https://learn.microsoft.com/en-us/windows/win32/api/dxgi1_5/nf-dxgi1_5-idxgioutput5-duplicateoutput1

DXGI will pick one of the supplied formats and convert the fullscreen buffer to that format before returning from IDXGIOutputDuplication::AcquireNextFrame

Thanks

Rita Han - MSFT 2,161 Reputation points

2020-11-30T03:25:24.627+00:00

Hello @Daniel Beneš , the conversion happens when "the current fullscreen buffer format is not contained in the pSupportedFormats array". So what's your current fullscreen buffer format?
Daniel Beneš 1 Reputation point

2020-11-30T19:31:42.333+00:00

Hello.
Well now I will look like an idiot, but where should I look? :D
I'm totally new to this, the project is this: https://github.com/psieg/Lightpack/blob/3dae6479de97a4e8adc58d170ea18c91cd769ec8/Software/grab/DDuplGrabber.cpp
I'm trying to learn something "on the way" but I must say that this is pretty hard.

EDIT:
The dxgiSwapChainDesc.BufferDesc contain dxgiModeDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
Rita Han - MSFT 2,161 Reputation points

2020-12-01T09:51:12.893+00:00

I fail to reproduce this issue because I got DXGI_ERROR_UNSUPPORTED error when calling DxgiOutput5->DuplicateOutput1(). Could you share (via GitHub) a mini, complete and reproducible sample so I can do a further investigation? Please make sure your private date removed before sharing. Thanks.
Daniel Beneš 1 Reputation point

2020-12-01T10:42:56.113+00:00

Hello.
In this branch is updated DXGI to 1_6: https://github.com/Benik3/Lightpack/tree/dxgi+HDR_older
Daniel Beneš 1 Reputation point

2021-11-09T18:18:53.883+00:00

Hi. I added below updated Microsoft example of DDupl to test this behaviour...

1 answer

Daniel Beneš 1 Reputation point

2021-10-31T17:09:50.023+00:00

Hello.
Back to this problem after long time.
I updated the Microsoft example of Desktop duplication: https://github.com/Benik3/Windows-classic-samples/tree/ddupl_update/Samples/DXGIDesktopDuplication
When I switch setting of windows to HDR, m_DeskDupl->GetDesc(&duplDesc); will return format R16G16B16A16_FLOAT.
Even that I have set up DuplicateOutput1 formats to only B8G8R8
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Geoffrey McRae 0 Reputation points

2023-10-21T13:32:49.42+00:00

DXGI will pick one of the supplied formats and convert the fullscreen buffer to that format before returning from IDXGIOutputDuplication::AcquireNextFrame

The output description from DXGI DD is of the source format, not the converted format. Once you acquire a frame, the frame should be in the format you requested which can be confirmed via ID3DTexture2D::GetDesc.

Note though that the conversion that DXGI DD does is VERY poor, converting HDR16 to HDR10 yields a practically useless output, it's better to do this in a HLSL shader yourself.

David Spruill 0 Reputation points Microsoft Employee

2024-02-13T01:02:30.9066667+00:00

Agreed that the default conversion DXGI does in this case is very poor - you might consider using the D2D HDR tonemapper effect to get SDR 8 bit frames from the HDR captures.
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