For reverse playback, we are always copying decoded
frame to downstream buffer. So the pool size can be
and need to be large enough.
In case that forward playback, however, we need to restrict
the max pool size for performance reason. Otherwise decoder
will keep copying decoded texture to downstream buffer pool
if decoding is faster than downstream throughput
performance and also there are queue element between them.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/2083>
Direct3D11 objects are COM, and most COM C APIs are verbose
(C++ is a little better). So, by using C++ APIs, we can make code
shorter and more readable.
Moreover, "ComPtr" helper class (which is C++ only) can be
utilized, that is very helpful for avoiding error-prone COM refcounting
issue/leak.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/2077>
Since our decoder DPB texture pool cannot be grown once it's
configured, we should pre-allocate sufficient number of textures
for zero-copy playback (but not too many).
The "min buffers" allocation query parameter can be a hint for
the number of required textures in addition to DPB size.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/2017>
Unlike other stateless decoder implementations (e.g., VA),
our DPB pool cannot be grown since we are using
texture array (pre-allocated, fixed-size d3d11 texture pool).
So, if there's no more available texture to use,
there's no way other than copying it to downstream's
d3d11 buffer pool. Otherwise deadlock will happen.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/2003>
Move d3d11 device, memory, buffer pool and minimal method
to gst-libs so that other plugins can access d3d11 resource.
Since Direct3D is primary graphics API on Windows, we need
this infrastructure for various plugins can share GPU resource
without downloading GPU memory.
Note that this implementation is public only for -bad scope
for now.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/464>
VP9 codec allows resizing reference frame by spec. Handling this case
is a bit tricky especially when the resizing happens on non-keyframe,
because pre-allocated decoder textures (i.e., dpb) have negotiated
resolution and to change resolution meanwhile decoding on non-keyframe,
each texture might need to be re-created, copied to new dpb somehow,
and re-negotiated with downstream.
Due to the complicated requirement of negotiation driven
resizing handling, this commit adds shader into d3d11decoder object
to resize only corresponding frames. Note that if the resolution change
is detected on keyframe, decoder will re-negotiate with downstream.
This implementation is similar to what we've done for nvcodec plugin.
Since supported resolution, profiles, and formats are device dependent ones,
single template caps cannot represent them, so this modification
will help autoplugging and fallback.
Note that the legacy gpu list and list of resolution to query were
taken from chromium's code.
Although the target platform of D3D11 decoding API are both desktop and UWP app,
DXVA header is blocked by "WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)"
which is meaning that that's only for desktop app.
To workaround this inconsistent annoyingness, we need to define WINAPI_PARTITION_DESKTOP
regardless of target WinAPI partition.
