Staging texture is used for memory transfer between system and
gpu memory. Apart from d3d11{upload,download} elements, however,
it should happen very rarely.
Before this commit, d3d11bufferpool was allocating at least one
staging texture in order to calculate cpu accessible memory size,
and it wasn't freed for later use of the texture unconditionally.
But it will increase system memory usage. Although GstD3D11memory
object is implemented so that support CPU access, most memory
transfer will happen in d3d11{upload,download} elements.
By this commit, the initial staging texture will be freed immediately
once cpu accessible memory size is calculated.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1627>
Because the size of texture array cannot be updated dynamically,
allocator should block the allocation request. This cannot be
done at buffer pool side if this d3d11 memory is shared among
multiple buffer objects. Note that setting NO_SHARE flag to
d3d11 memory is very inefficient. It would cause most likey
copy of the d3d11 texture.
Use consistent memory layout between dxva and other shader use case.
For example, use DXGI_FORMAT_NV12 texture format instead of
two textures with DXGI_FORMAT_R8_UNORM and DXGI_FORMAT_R8G8_UNORM.
This reverts commit ddd13fc7c0
Dynamic usage can reduce the number of copy per frame but make
things complicated and the benefit seems to not significant.
Also since we don't provide _map() method for the dynamic usage,
application cannot read buffers which make "last-sample" property
unusable in case of d3d11videosink.
A ID3D11Texture2D memory can consist of multiple planes with array.
For array typed memory, GstD3D11Allocator will allocate new GstD3D11Memory
with increased reference count to the ID3D11Texture2D but different array index.
D3D11 dynamic texture is a special memory type, which is mainly used for
frequent CPU write access to the texture. For now, this texture type
does not support gst_memory_{map,unmap}
* Create staging texture only when the CPU access is requested.
Note that we should avoid the CPU access to d3d11 memory as mush as possible.
Incoming d3d11upload and d3d11download will take this GPU memory upload/download.
* Upload/Download texture memory from/to staging only if it needed, similar to
GstGL PBO implementation.
* Define more dxgi formats for future usage (e.g., color conversion, dxva2 decoder).
Because I420_* formats are not supported formats by dxgi, each plane should
be handled likewise GstGL separately, but NV12/P10 formats might be supported ones.
So we decide the number of d3d11memory per GstBuffer for video memory depending on
OS version and dxgi format. For instance, if NV12 is supported by OS,
only one d3d11memory with DXGI_FORMAT_NV12 texture can be allocated by this commit.
One use case of such texture is DXVA. In case DXVA decoder, it might need to produce decoded data
to one DXGI_FORMAT_NV12 instead of seperate Y and UV planes.
Such behavior will be controlled via configuration of GstD3D11BufferPool and
default configuration is separate resources per plane.
Direct3D11 was shipped as part of Windows7 and it's obviously
primary graphics API on Windows.
This plugin includes HDR10 rendering if following requirements are satisfied
* IDXGISwapChain4::SetHDRMetaData is available (decleared in dxgi1_5.h)
* Display can support DXGI_COLOR_SPACE_RGB_FULL_G2084_NONE_P2020 color space
* Upstream provides 10 bitdepth format with smpte-st 2084 static metadata
