The AV1 codec needs to support the film grain feature. When the film
grain feature is enabled, we need two surfaces as the output of the
decoded picture, one without film grain effect and the other one with
it. The first one acts as the reference and is needed for later pictures'
reconstruction, and the second one is the real display output.
So we need to attach another aux surface to the gst buffer/mem and make
that aux surface as the target of vaBeginPicture.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1636>
Since GstVaDecodePicture is destroyed completely with its free() function and
it's used as destroy notify by codecs picture, there's no need to call
gst_va_decoder_destroy_buffers() externally, since the codecs base classes
destroy the codec picture when it's required.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1841>
The current way of GstVaDecodePicture's finalize will leak some
resource such as parameter buffers and slice data.
The current way deliberately leaves these resource releasing logic
to va decoder related function and trigger a warning if we free the
GstVaDecodePicture without releasing these resources.
But in practice, sometimes, you do not have the chance to release
these resource before picture is freed. For example, H264/Mpeg2
support multi slice NALs/Packets for one frame. It is possible that
we already succeed to parse and generate the first several slices
data by _decode_slice(), but then we get a wrong slice NAL/packet
and fail to parse it. We decide to discard the whole frame in the
decoder's base class, it just free the current picture and does not
trigger sub class's function again. In this kind of cases, we do
not have the chance to cleanup the resource, and the resource will
be leaked.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1841>
For the allocator to create surfaces with the correct chroma an
fourcc, it should use a surface format, not necessarily the negotiated
format.
Instead of the previous arbitrary extra formats list, the decoder
extracts the valid pixel formats from the given VA config, and pass
that list to the allocator which stores it (full transfer).
Then, when the allocator allocates a new surface, it looks for a
surface color format chroma-compatible with the negotiated image color
format.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1483>
New plugin with an element for H.264 decoding with VA-API. This novel
approach, different from gstreamer-vaapi, uses gstcodecs library for
state handling.
The code is expected to looks cleaner because it uses VA-API without
further layers or wrappers.
* It uses the first supported DRM device as default VA display (other
displays will be supported through user's GstContext)
* Requires libva >= 1.6
* No multiview/stereo profiles neither interlaced streams because
gstcodecs doesn't handle them yet
* It is incompatible with gstreamer-vaapi
* Even if memory:VAMemory is exposed, it is not handled yet by any
other element
* Caps templates are generated dynamically querying VAAPI, but YV12
and I420 are added for system memory caps because they seem to be
supported for all the drivers when downloading frames onto main
memory, as they are used by xvimagesink and others, avoiding color
conversion.
* Surfaces aren't bounded to context, so they can grow beyond the DBP
size, allowing smooth reverse playback.
* There isn't yet error handling and recovery.
* 10-bit H.264 streams aren't supported by libva.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1379>
