The patch adds a serios of changes to support dynamic resolution
change and efficient utilization of resources.
Major changes:
-- Use MSDK's apis to retrieve the headers instead of only relying
on upsteram notification. For eg: avc decoder requires SEI header
information for dpb count calculation which we don't get from caps.
-- For all codecs other than VP9, we force the reset of decoder
if resoultion changes to fit with gstreamer flow. VP9 enfource
the hard reset only if the new resolution is bigger.
-- delay the src caps setting till msdk api's invokation in
handle_frame to avoid caching multiple configuration values
-- ensure pool negotiation is based on decoder's allocation_caps.
--dynamic resoluttion change use an explicit allocation_query
to reclaim the buffers before closing the decoder (thanks to v4l2dec)
--In case if we don't get upstream notification of res change (for eg,
this can can happen for vp9 frames with ivfheader where ivfparse
is not able to notify the dynamic changes), we handle the the case
based on MFX_ERR_INCOMPATIBLE_VIDEO_PARAM which is the return value
of MFXVideoDECODE_DecodeFrameAsync
-- calculate the minimum surfaces to be preallocated based on
msdk suggestion, downstream requirement, async depth and scratch surface
count for smooth display.
https://bugzilla.gnome.org/show_bug.cgi?id=796566
The new property "output-order" can be set to either "display" order
which is the default where frames will be outputting in display order,
or "decoded-order" which will be outputting the frames in decoded order.
The "decoded order" output is generally useful for debugging. But there
are few
customers who use it for low-latency streaming. For eg if the customer
already knows that the stream doesn't have b-frames (which means no
algorithm requires for display order calculation), then they can use
"decoded-order"
output to skip some of the DPB logic to avoid the frame accumulation at
start-up.
The root cause of the above issue is a bit of unclarity in h264 spec +
lazy implementation of many H264 encoders; This is well handled in
gstreamer-vaapi using "low-latency" property:
https://bugzilla.gnome.org/show_bug.cgi?id=762509https://bugzilla.gnome.org/show_bug.cgi?id=795783
The gst-msdk decoders prefer packetized streams as input
and in this case we can avoid unnecessary input bitstream copy
to mfxBitstream. This works fine for codecs like h264 where
we only support byte-stream with au alignment. Other format
conversions should be done thorugh parsers. But this won't work
for codecs like vc1 where we don't have an autoplugged parser.
Even the parser is not capable to do format conversions.
Packetizing through base decoders parse() routine will bring a
lot of uncecessary of complexities and codecparser libraray dependency.
So we just use an interal gst_adaper to keep track of bitstream
which is not consumed by msdk durig AsynchronusDecoding.
This adapter will get used only if subclass implementations
set the "is_packetized" to FALSE for msdk base encoder.
https://bugzilla.gnome.org/show_bug.cgi?id=792589
How to share/create GstMsdkcontext is the following:
- Search GstMsdkContext if there's in the pipeline.
- If found, check if it's decoder, encoder or vpp by job type.
- If it's same job type, it creates another instance of
GstMsdkContext
with joined-session.
- Otherwise just use the shared GstMsdkContext.
- If not found, just creates new instance of GstMsdkContext.
https://bugzilla.gnome.org/show_bug.cgi?id=790752
1\ In decide_allocation, it makes its own msdk bufferpool.
- If downstream supports video meta, it just replace it with the msdk
bufferpool.
- If not, it uses the msdk bufferpool as a side pool, which will be
decoded into.
and will copy it to downstream's bufferpool.
2\ Decide if using video memory or system memory.
- This is not completed in this patch.
- It might be decided in update_src_caps.
- But tested for both system memory and video memory cases.
https://bugzilla.gnome.org/show_bug.cgi?id=790752
Makes GstMsdkContext to be a descendant of GstObject so that
we could track the life-cycle of the session of the driver.
Also replaces MsdkContext with this one.
Keeps msdk_d3d.c alive for the future.
https://bugzilla.gnome.org/show_bug.cgi?id=790752
