Do not carry over segmentation flags from previous frames. The spec
says in 7.2.10 that the feature data carry over from previous frames
if not updated, but the flags do not.
Consider what would happen if a flag B is to depend on a flag A, and
B carries over as set from another frame. Further consider that A is
now not set in this particular frame. This leads to the invalid state
in which flag B is set but flag A isn't.
This might cause the bitstream to be rejected by accelerators down
the line.
Fix it.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/2203>
The default implementation was required when superframe parsing
was handled by vp9decoder. For instance, if a superframe consists
of multiple frames with show_existing_frame header, it was vague
that which GstVp9Picture should consume GstVideoCodecFrame.
After 1.18 release, we introduced vp9parse element and
superframe should be handled by upstream vp9parse elemenet now.
So, we don't need to care about the superframe at vp9decoder class
level anymore. Simply, a frame corresponding to show_existing_frame
can be dropped if subclass doesn't implement duplicate_picture().
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/2151>
Existing VP9 parser implementation doesn't provide information
required by other stateless decoding APIs (i.e., DXVA and NVDEC),
specifically loop filter and segmentation parameters might not exist
current frame. So parser needs to fill the information by using previously
parsed information.
We can update the gstvp9parser implementation so that it can provide
all information required by stateless decoding APIs with a huge API break,
or adding more ugly struct in it.
Instead doing as such, this commit introduce a new VP9 parser implementation.
What is different from existing one?
* All variables will follow the specification as much as possible:
VP9 Bitstream & Decoding Process Specification - v0.6 31st March 2016
* Parser will fill all the required information for decoding frame
to GstVp9FrameHeader struct. In case of old VP9 parser,
user needs to read additional data from parser's member variables.
* GstVp9StatefulParser object struct is completely completely opaque
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/2112>
In the current code, we call frame_unref only when the frame is
outputted. This is OK for normal playback, but when seek happens,
the frames stored in DPB is not outputted and causes some memory
leak.
The correct way is that we should call frame_unref every time we
finish the handle_frame(), which is also the behaviour of H264/H265
decoder.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/2014>
* Invoke GstH265DecoderClass::new_sequence() method per interlaced
stream status update so that subclass can update caps.
* Parse picture timing SEI and set buffer flags on GstH265Picture
object. Subclass can refer to it like that of our h264decoder
implementation.
* Remove pointless GstH265PictureField enum
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/2008>
Some decoding APIs support delayed output or a command for decoding
a frame doesn't need to be sequential to corresponding command for
getting decoded frame. For instance, subclass might be able to
request decoding for multiple frames and then get for one (oldest)
decoded frame or so.
If aforementioned case is supported by specific decoding API,
delayed output might show better throughput performance.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1925>
Spec says:
In a frame picture top_field_first being set to ‘1’ indicates that the
top field of the reconstructed frame is the first field output by the
decoding process. top_field_first being set to ‘0’ indicates that the
bottom field of the reconstructed frame is the first field output by
decoding process.
Here, the "output" should be interpreted just as the output order, not
including the decoding order. The field should be decoded as the order
they comes in the stream. Namely, no matter top_field_first is 0 or 1,
the first coming field is the first one to be decoded.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1929>
In case that "pic_order_cnt_type" is equal to zero, ref picture
list for B slice should not include non-existing picture
as per spec 8.2.4.2.3. And, the second field is not needed
for the process of frame picture reference list construction
since it needs to be frame unit, not field picture in that case.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1812>
We were trying to construct reference picture list even for
I slice before this commit. Reference list is required only for
P, SP and B slices. Also, if all existing reference pictures
are gap pictures, we don't need to construct lists.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1812>
Initial support for interlaced stream. Subclass should implement
new_field_picture() vfunc. Otherwise, baseclass will assume that
subclass doesn't support interlaced stream.
Restrictions:
* Reference picture modification process for interlaced stream
is not implemented yet
* PAFF (Picture Adaptive Frame Field) is not properly implemented.
* Field display ordering (e.g., top-field-first) decision should
be enhanced via picture timing SEI parsing
* Gap in field picture should be handled
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1534>
Managing reference picture type by using two variables
(ref and long_term) seems to be redundant and that can be
represented by using a single enum value.
This is to sync this implementation with gstreamer-vaapi so that
make comparison between this and gstreamer-vaapi easier and also
in order to minimize the change required for subclass to be able
to support interlaced.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1534>
