FORMAT_B8G8R8G8_422_UNORM is not available in newer drivers

Gaming and Visualization Technologies APIs Vulkan
1

We have noticed that FORMAT_B8G8R8G8_422_UNORM is unavailable with recent Nvidia drivers at least on the 1080 ti and 2080 ti. This is even reported with vulkaninfo.

The change was probably introduced between v561 and v565. There is nothing about dropping any formats in the official changelog. Is there anything that we miss?

2

PS: The problem also happens with a 5090 on v575

3

Here is some visualization of the problem: The support just seems to have stopped:
The first 2 rows are 550/561, the last three are 570/577/582. Rows 1/3 are Linux. Rows 2/4/5 are windows

grafik
grafik1380×241 21.1 KB

4

Here is the same for the 2080 ti. All Linux machines. Last row is 580. The other rows are 555/560.

grafik
grafik1445×260 26.2 KB

5

The changelog (https://developer.nvidia.com/vulkan-driver) has no entry between 553 and 570

6

Here is a small test program which shows if the format is available on the current machine. It might help to analyze the problem further:

main.cpp.txt (1.6 KB)

7

Thank you for bringing this to our attention. Support for the interleaved YCbCr formats VK_FORMAT_G8B8G8R8_422_UNORM and VK_FORMAT_B8G8R8G8_422_UNORM was intentionally disabled in recent drivers due to architectural changes that made these formats incompatible. We apologize for not communicating this earlier.

The Vulkan specification allows implementations to optionally support YCbCr formats. Applications should query format support at runtime via vkGetPhysicalDeviceFormatProperties and handle the case where a format is not available.

If these formats are required, applications can alternatively implement YCbCr color conversion in a shader. One approach is to store the interleaved data using VK_FORMAT_R8G8B8A8_UNORM at half width and perform the color conversion during shader processing.