Function probe_vulkan_encode 

pub fn probe_vulkan_encode(
    device: &AVHWDeviceContext,
    width: u32,
    height: u32,
) -> Result<VulkanEncodeProbe, EncodeError>

Opens h264_vulkan against device and encodes one pool frame.

The frame is left as the pool allocated it: this answers whether the session can be created and driven on this device, not what the picture looks like.

Errors

Returns an adapter failure when the encoder is absent, the pool cannot be created, the session cannot open, or no packet is produced.