borderless top-most style full screen mode support.
Basically fullscreen toggle mode is disabled by default. To enable it
use "fullscreen-toggle-mode" property to allow fullscreen mode change
by user input and/or property.
In some cases, rendering and dxgi (e.g., swapchain) APIs should be
called from window message pump thread, but current design (dedicated d3d11 thread)
make it impossible. To solve it, change concurrency model to locking based one
from single-thread model.
In earlier implementation of d3d11videosink where no shader was implemented,
the aspect ratio and render size were adjusted by manipulating the backbuffer size
with unintuitive formula. Since now we do color conversion and resize using
shader, we can remove the hack.
... and use SetParent() WIN32 API when external window is used.
Depending on DXGI swap effect, the external window might not be
reusable by another backend. To preserve the external window's property
and setting, drawing to internal window seems to be safer way.
If d3d11window does not convert format internally, shader resource view
is not required. Note that shader resource view is used for
color conversion using shader but when conversion is not required,
we just copy input input texture to backbuffer.
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.
Depending on selected feature level, d3d11 API usage can be different.
Instead of querying the selected feature level by user whenever required,
store it once by d3d11device.
Do not accept any GstD3D11Device context which has different adapter
index from the required one. For example, if a d3d11 element is expecting
d3d11 device with adapter 1 (i.e., the second GPU), any d3d11 device
context having different adapter could not be shared with
the d3d11 element.
