With the asynchronous slice decoding, we only queue up to 2 slices
per frames. That side effect is that now we are dequeuing bitstream
buffers in both decoding and presentation order. This would lead to
a bitstream buffer from a previous frame being dequeued instead of
the expected last slice buffer and lead to us trying to queue an
already queued bitstream buffer.
We now fix this by tracking pending requests. As request are executed
in decoding order, we marking a request done, we can effectively
dequeue bitstream buffer from all previous request, as they have been
executed already.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1395>
The decoder is not being access from multiple threads, instead it is
always protected by the streaming lock. For this reason, a
GstAtomicQueue for the request pool is overkill and may even introduce
unneeded overhead. Use a GstQueueArray in replacement, the
GstQueueArray is a good fit since the number of item is predictable and
unlikely to vary at run-time.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1395>
In slice mode, we'll do one request per slice. In order to recycle
bitstream buffer, and not run-out, wait for the last pending
request to complete and mark it done.
We only wait after having queued the current slice in order to reduce
that potential driver starvation and maintain performance (using dual
buffering).
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1395>
A pipeline like this:
closedcaption/x-cea-708,format=cdp,framerate=30000/1001 ! ccconverter ! closedcaption/x-cea-708,format=cc_data
would produce a critical/assert:
GStreamer-CRITICAL **: 14:21:11.509: gst_util_fraction_multiply: assertion 'a_d != 0' failed
because there would be no framerate field on ccconverter's output.
Fixed by always fixating a framerate if the input has a framerate.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1393>
Unclear why hotdoc wants 'gstavtp' as the plugin name here,
that's just wrong.
Add since marker and mark private subclasses as plugin API
so hotdoc knows they belong to the plugin and aren't external.
Fix GstAvtpAafTstampMode get_type() function.
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>
There are some streams, with HRD, where the the calculated
max_dpb_frames is zero (max_dpb_mbs is less than size mb). In order to
get the dbp size it is required to rely on the VUI parameters if they
are present.
According to the spec Annex E.2.1
**max_dec_frame_buffering** specifies the required size of the HRD
decoded picture buffer (DPB) in units of frame buffers. It is a
requirement of bitstream conformance that the coded video sequence
shall not require a decoded picture buffer with size of more than
Max(1, max_dec_frame_buffering) frame buffers to enable the output of
decoded pictures at the output times specified by dpb_output_delay of
the picture timing SEI messages. The value of max_dec_frame_buffering
shall be greater than or equal to max_num_ref_frames. An upper bound
for the value of max_dec_frame_buffering is specified by the level
limits in clauses A.3.1, A.3.2, G.10.2.1, and H.10.2.
When the max_dec_frame_buffering syntax element is not present, the
value of max_dec_frame_buffering shall be inferred as follows:
– If profile_idc is equal to 44, 86, 100, 110, 122, or 244 and
constraint_set3_flag is equal to 1, the value of
max_dec_frame_buffering shall be inferred to be equal to 0.
– Otherwise (profile_idc is not equal to 44, 86, 100, 110, 122, or 244
or constraint_set3_flag is equal to 0), the value of
max_dec_frame_buffering shall be inferred to be equal to MaxDpbFrames.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1381>
