When GstVideoMeta maps were used, the supporting functions incorrectly
used gst_buffer_get_memory() instead of gst_buffer_peek_memory(), thus
always increasing the associated GstMemory reference count and giving
zero chance to actually release that, and subsequently the VA display.
Reset the buffer pool allocator only if the config caps changed in a
sensible way: format or resolution change. i.e. don't bother with
other caps like colorimetry et al. as this doesn't affect the way to
allocate VA surfaces or images.
Enable read and write mappings only if direct-rendering is supported.
Otherwise, this means that we may need to download data from the VA
surface first for correctness, even if the VA surface doesn't need to
be read at all. i.e. sometimes, READWRITE mappings are meant for
surfaces that are written to first, and read afterwards for further
processing.
https://bugzilla.gnome.org/show_bug.cgi?id=704078
Fix check for direct-rendering if the creation of VA surfaces with
an explicit pixel format is not support, e.g. VA-API < 0.34.0, and
that we tried to allocate a VA surface based on the corresponding
chroma type. i.e. in that particular case, we have to make sure that
the derived image has actually the expected format.
Fix GstVaapiVideoBufferPool::reset_buffer() to reset the underlying
memory resources, and more particularly the VA surface proxy. Most
importantly, the GstVaapiVideoMeta is retained. Cached surface in
memory are released, thus triggering a new allocation the next time
we need to map the buffer.
Make sure GstVaapiVideoMemory allocates VA surface proxies from a
pool stored in the parent VA memory allocator.
This fixes the following scenario:
- VA video buffer 1 is allocated from a buffer pool
- Another video buffer is created, and inherits info from buffer 1
- Buffer 1 is released, thus pushing it back to the buffer pool
- New buffer alloc request comes it, this yields buffer 1 back
- At this stage, buffers 1 and 2 still share the same underlying VA
surface, but buffer 2 was already submitted downstream for further
processing, thus conflicting with additional processing we were
about to perform on buffer 1.
Maybe the core GstBufferPool implementation should have been fixed
instead to actually make sure that the returned GstBuffer memory we
found from the pool is writable?
Fix reference counting issue whereby gst_memory_init() does not hold
an extra reference to the GstAllocator. So, there could be situations
where the last instance of GstVaapiVideoAllocator gets released before
a dangling GstVaapiVideoMemory object, thus possibly leading to a crash.
Adapt GstVaapiVideoMemory allocator to support creation of VA surfaces
with an explicit pixel format. This allows for direct rendering to
VA surface memory from a software decoder.
Allow plain gst_buffer_map() interface to work with gstreamer-vaapi
video buffers, i.e. expose the underlying GstVaapiSurfaceProxy to the
caller. This is the only sensible enough thing to do in this mode as
the underlying surface pixels need to be extracted through an explicit
call to the gst_video_frame_map() function instead.
A possible use-case of this is to implement a "handoff" signal handler
to fakesink or identity element for further processing.
Fix gst_vaapi_video_allocator_new() to silently check for direct-rendering
mode support, and not trigger fatal-criticals if either test surface or
image could not be created. Typical case: pixel format mismatch, e.g. NV12
supported by most hardware vs. I420 supported by most software decoders.
On map, ensure we have GST_MAP_WRITE flags since this is only what we
support for now. Likewise, on unmap, make sure that the VA image is
unmapped for either read or write, while still committing it to the
VA surface if write was requested.
Implement GstVideoMeta::{,un}map() to support raw YUV buffer upload when
the last component is unmapped. Downloads are not supported yet. The aim
was to first support SW decoding + HW accelerated rendering (vaapisink).
e.g. for Wayland.
Add initial support for GstVaapiVideoMemory backed buffer pool. The memory
object currently holds a reference to GstVaapiVideoMeta.
Signed-off-by: Gwenole Beauchesne <gwenole.beauchesne@intel.com>
