D3D12_HEAP_FLAG_CREATE_NOT_ZEROED flag was introduced as of
Windows 10 May 2020 Update, and older versions don't understand
the heap flag. Checks the feature support and enables the
D3D12_HEAP_FLAG_CREATE_NOT_ZEROED only if it's supported by OS
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/7573>
null event NT handle to ID3D12Fence::SetEventOnCompletion()
will block the calling CPU thread already, thus it has no point that
creating an event NT handle in order to immediate wait for fence at CPU-side.
Note that passing a valid event NT handle to the fence API might be useful
when we need to wait for the fence value later (or timeout is required),
or want to wait for multiple fences at once via WaitForMultipleObjects().
But it's not a considered use case for now.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/7176>
Since a buffer resource will occupy at least 64KB,
allocating upload resource per decoding command might not be
an optimal approach. Instead, use sub-region of a upload resource
for multiple decoding command if sub-regions are not overlapped
each other.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/7108>
Observed Intel GPU driver crash when multiple decoders are
configured in a process. It might be because of frequent
command queue alloc/free or too many in-flight decoding commands.
In order to make command queue persistent and limit the number of
in-flight command lists, holds global decoding command queue.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/7019>
Address below message reported by SDK debug layer.
ID3D12Device::CheckFeatureSupport: Unsupported Decode Profile Specified.
Use ID3D12VideoDevice::CheckFeatureSupport with D3D12_FEATURE_VIDEO_DECODE_PROFILES
to retrieve a list of supported profiles
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/6839>
A DPB buffer held by codec picture object may not be writable
at the moment, then gst_buffer_make_writable() will unref passed buffer.
Specifically, the use after free or double free can happen if:
* Crop meta of buffer copy is required because of non-zero
top-left crop position
* zero-copy is possible with crop meta
* A picture was duplicated, interlaced h264 stream for example
Interlaced h264 stream with non-zero top-left crop position
is not very common but it's possible configuration in theory.
Thus gst_buffer_make_writable() should be called with
GstVideoCodecFrame.output_buffer directly.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/6706>
In case of tier 1 decoder, always use reference-only picture to avoid
fixed-size pool limitation and output decoded picture without
copy even for negative rate. Also do not use copy queue for GPU to GPU
copy. Copy queue is specialized for upload/download and may occupy
PCIE bandwidth. Use direct queue as recommended by vendors.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/5877>
On flush event, baseclass will discard all pictures from DPB
but there can be still in-flight commands not finished yet.
Use our command queue, allocator and fence data helper objects
to keep resource available during command execution.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/5877>
Zero initialization would have overhead and it's not required
most cases except for textures. Use CREATE_NOT_ZEROED flag
in case of buffer resource or if a texture will be rendered without any
prior read operation.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/5875>
To achieve maximum throughput, waiting on command commit thread
is not ideal. And render-delay will introduce unwanted latency.
Best is to split thread and wait finished decoding job in a dedicated
output thread
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/5812>
