openh264dec: Fix input state handling and propagation of upstream caps fields
openh264enc: Don't set caps manually

This will break the order of events in GStreamer.
openh264dec: Remove invalid sprops-parameter-set handling

This only exists on RTP caps, not H264 caps.
openh264dec: Fix various crashes on ::stop()
openh264dec: Don't forget to unref the input state
openh264dec: Optimize frame copying a bit
openh264dec: Add support for GstVideoMeta

This will make operation with various sinks faster for free.
openh264enc: Add support for GstVideoMeta

This will allow upstream elements to work more efficiently.
openh264enc: Fix up caps and stride handling
openh264enc: We always get a single frame as output, not a NAL

No need to accumulate NALs.
openh264enc: Properly drain the encoder on ::finish()
openh264dec: Properly drain codec on ::finish()
openh264dec: As we require NAL alignment from upstream we don't need to parse anything
openh264dec: GstVideoDecoder works on frames, not sub-frames (e.g. NALs)

And we can just pass complete AUs to the decoder without problems.
openh264dec: Don't drop videocodec frames if we can't decode them *yet*

Fixes jittery playback of streams with B frames.
openh264dec: Try to handle frame reordering

As openh264 has no way to attach any IDs to input frames that we then get on
the output frames, we have to assume that the input has valid PTS. We just
take the frame with the oldest PTS, and if there is no PTS information we take
the one with the oldest DTS.
openh264: Add FIXME comment about missing API in openh264
openh264dec: On ::finish() stop trying if the decoder returned that no output is available
openh264dec: The codec can only do baseline so simplify the code a bit

and declare this also on the sinkpad caps.

With baseline profile there are no B-frames or frame reordering.
openh264enc: make denoise work

https://bugzilla.gnome.org/show_bug.cgi?id=737894