Determining which swap chain formats are supported

Question

When calling IDXGIFactory1::CreateSwapChain with DXGI_FORMAT_B5G6R5_UNORM I get an error that this format isn't supported, specifically E_INVALIDARG One or more arguments are invalid. However, this works fine with a more standard format like DXGI_FORMAT_B8G8R8A8_UNORM.

I'm trying to understand how I can know which swap chain formats are supported. From digging around in the documentation, I can find lists of supported formats for "render targets", but this doesn't appear to be the same set of formats supported for swap chains. B5G6R5 does need 11.1 to have required support for most uses, but it's working as a render target.

As a test, I looped through all formats and attempted to create swap chains with each. Of the 118 formats, only 8 appear to be supported on my machine (RTX 2070):

DXGI_FORMAT_R16G16B16A16_FLOAT
DXGI_FORMAT_R10G10B10A2_UNORM
DXGI_FORMAT_R8G8B8A8_UNORM
DXGI_FORMAT_R8G8B8A8_UNORM_SRGB
DXGI_FORMAT_B8G8R8A8_UNORM
DXGI_FORMAT_B8G8R8A8_UNORM_SRGB
DXGI_FORMAT_NV12
DXGI_FORMAT_YUY2

What is the proper way to know which swap chain formats are supported?

For additional context, I'm doing off-screen rendering to a 16-bit (565) format. I have an optional "preview window" that I open occasionally to quickly see the rendering results. When I create the window I create a swap chain and do a copy from the real render target into the swap chain back buffer. I'm targeting DirectX 11 or 11.1. I'm able to render to the B5G6R5 format just fine, it's only the swap chain that complains. I'm running Windows 10 1909.

Here's a Gist with resource creation snippets and a full code sample. https://gist.github.com/akbyrd/c9d312048b49c5bd607ceba084d95bd0

This is documented here: docs.microsoft.com/en-us/previous-versions/windows/desktop/… . Not sure about DXGI_FORMAT_NV12 and DXGI_FORMAT_YUY2 — Simon Mourier

Chuck Walbourn Chuck Walbourn · Accepted Answer · 2020-07-30T21:18:31

For the swap-chain, it must be supported for "Display Scan-Out". If you need to check a format support at runtime, you can use:

UINT formatSupport = 0;
if (FAILED(device->CheckFormatSupport(backBufferFormat, &formatSupport)))
    formatSupport = 0;

UINT32 required = D3D11_FORMAT_SUPPORT_RENDER_TARGET | D3D11_FORMAT_SUPPORT_DISPLAY;
if ((formatSupport & required) != required)
{
    // Not supported
}

For all Direct3D Hardware Feature Levels devices, you can always count on DXGI_FORMAT_R8G8B8A8_UNORM working. Unless you are on Windows Vista or ancient WDDM 1.0 legacy drivers, you can also count on DXGI_FORMAT_B8G8R8A8_UNORM

For Direct3D Hardware Feature Level 10.0 or better devices, you can also count on DXGI_FORMAT_R16G16B16A16_FLOAT and DXGI_FORMAT_R10G10B10A2_UNORM being supported.

You can also count on all Direct3D Hardware Feature Level devices supporting DXGI_FORMAT_R8G8B8A8_UNORM_SRGB and DXGI_FORMAT_B8G8R8A8_UNORM_SRGB for swap-chains if you are using the 'legacy' swap effects. For modern swap effects which are required for DirectX 12 and recommended on Windows 10 for DirectX 11 (see this blog post), the swapchain buffer is not created with _SRGB but instead you create just the render target view with it.

See Anatomy of Direct3D 11 Create Device

Determining which swap chain formats are supported

1 Answers