Use-case: with AMD hardware, we want to decode NV12 buffers via VA-API, then directly display them via KMS. This works fine if the KMS planes aren't rotated, but fails when we try to rotate them.
The reason is that VA-API gives us some LINEAR buffers and AMD display hardware can't rotate LINEAR buffers. We need tiled buffers.
To fix this, it would be nice to be able to provide a list of DRM modifiers when creating a VASurface. The driver would only be allowed to pick a modifier from this list.
This is how other APIs handle this: both GBM and Vulkan let users pass a list of modifiers when allocating memory.
We could add VASurfaceAttribDRMFormatModifiers, with a pointer to a list of modifiers.
Use-case: with AMD hardware, we want to decode NV12 buffers via VA-API, then directly display them via KMS. This works fine if the KMS planes aren't rotated, but fails when we try to rotate them.
The reason is that VA-API gives us some LINEAR buffers and AMD display hardware can't rotate LINEAR buffers. We need tiled buffers.
To fix this, it would be nice to be able to provide a list of DRM modifiers when creating a VASurface. The driver would only be allowed to pick a modifier from this list.
This is how other APIs handle this: both GBM and Vulkan let users pass a list of modifiers when allocating memory.
We could add
VASurfaceAttribDRMFormatModifiers, with a pointer to a list of modifiers.