[FFmpeg-devel] [PATCH V3 3/5] libavutil/hwcontext_vulkan: Allocate vkFrame in one memory

[Lynne]

26 Nov 2021, 03:54 by wenbin.chen at intel.com:

> The vaapi can import external frame, but the planes of the external
> frames should be in the same drm object. A new option "contiguous_planes"
> is added to device. This flag tells device to allocate places in one
> memory. When device is derived from vaapi this flag will be enabled.
> A new flag frame_flag is also added to AVVulkanFramesContext. User
> can use this flag to force enable or disable this behaviour.
> A new variable "offset "is added to AVVKFrame. It describe describe the
> offset from the memory currently bound to the VkImage.
>
> Signed-off-by: Wenbin Chen <wenbin.chen at intel.com>
>

Why is a new offset variable needed?
vkGetImageSubresourceLayout is valid for DRM tiled images.
According to the specs,
"If the image’s tiling is VK_IMAGE_TILING_DRM_FORMAT_MODIFIER_EXT, then vkGetImageSubresourceLayout describes one memory plane of the image. If the image’s tiling is VK_IMAGE_TILING_DRM_FORMAT_MODIFIER_EXT and the image is non-linear, then the returned layout has an implementation-dependent meaning; the vendor of the image’s DRM format modifier may provide documentation that explains how to interpret the returned layout.".

Isn't this what you already have in the offset field?