In certain cases, roundedcorners would negotiate to I420 even when user
supplied a non-zero border radius.
For example, the below pipeline leads to I420 being negotiated even
though a non-zero border radius was given. Ideally, this pipeline
should have failed at the negotiation stage.
```bash
gst-launch-1.0 -v \
videotestsrc num-buffers=1000 pattern=white ! \
video/x-raw,width=320,height=180 ! \
roundedcorners border-radius-px=10 ! videobox border-alpha=0 top=-10 left=-10 right=-10 bottom=-10 fill=yellow ! \
compositor name=comp sink_0::xpos=960 sink_0::ypos=0 sink_0::width=320 sink_0::height=180 sink_0::alpha=1.0 sink_1::xpos=960 sink_1::ypos=180 sink_1::width=320 sink_1::height=180 sink_1::alpha=1.0 \
sink_2::xpos=960 sink_2::ypos=360 sink_2::width=320 sink_2::height=180 sink_2::alpha=1.0 sink_3::xpos=0 sink_3::ypos=0 sink_3::width=960 sink_3::height=720 sink_3::alpha=1.0 ! \
video/x-raw,width=1280,height=720! x264enc ! mp4mux ! filesink location=test.mp4 \
videotestsrc num-buffers=1000 pattern=red ! \
video/x-raw,width=320,height=180 ! roundedcorners border-radius-px=10 ! comp. \
videotestsrc num-buffers=1000 pattern=blue ! \
video/x-raw,width=320,height=180 ! roundedcorners border-radius-px=10 ! comp. \
videotestsrc num-buffers=1000 pattern=green ! \
video/x-raw,width=960,height=720 ! roundedcorners border-radius-px=10 ! comp.
```
If border radius is non-zero, we should not really allow negotiation
to select I420. Fix this by returning only A420 for border-radius > 0
in `transform_caps` instead of returning both like earlier.
Another example of a simpler pipeline like below which would earlier work
```bash
gst-launch-1.0 videotestsrc pattern=red ! videoconvert ! video/x-raw,width=1923,height=1087,format=I420 ! roundedcorners border-radius-px=40 ! video/x-raw,format=I420 ! videoconvert ! gtksink
```
now fails with
```bash
WARNING: erroneous pipeline: could not link roundedcorners0 to videoconvert1, roundedcorners0 can't handle caps video/x-raw, format=(string)I420
```
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-rs/-/merge_requests/1216>
To avoid special characters getting de-duplicated by the decoder, we
insert no-op control commands after those. The no-op command must be
picked according to the mode we're in however, inserting
"resume_caption_loading" commands in roll-up mode caused obvious issues.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-rs/-/merge_requests/1161>
Allowed downstream caps might hold multiple structures, simply fixating
the first structure is not enough, tttocea608 must also create caps with
a single structure from there (or remove the remaining structures, but
new caps seems cleaner)
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-rs/-/merge_requests/1161>
When passthrough=false at construction and the transcription bin
is linked after receiving video caps (and not on state change),
there could be a race where transcription-bin was linked with
tee but state change of the transcription-bin was not finished.
If upstream pushed a buffer at that point, it got a flushing flow
return and stopped streaming.
This is the same issue and the same fix as 558656deb5
for the initial passthrough=false case.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-rs/-/merge_requests/1161>
Create a single, global GDK GL context and the corresponding GStreamer
GL display and wrapped GStreamer GL context when initializing the first
sink and continue using that for all further sinks.
Additionally, don't create a full GStreamer GL context inside the sink
but only distribute the wrapped GL context in the pipeline so that
elements that actually need a full GL context can create one that is
sharing with that one. The sink itself does not need a full GStreamer GL
context.
Then inside the sink check that any GL memory that arrives was created
by a GL context that can share with the wrapped GDK GL context and only
then use it.
And lastly, use the correct GL contexts for a) creating a sync point and
b) actually waiting on it.
Fixes https://gitlab.freedesktop.org/gstreamer/gst-plugins-rs/-/issues/318
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-rs/-/merge_requests/1101>
The first time might return `EAGAIN` if there are pending frames but
there is no decoded frame available yet. The second time it will
actually wait for frames to become available and only start returning
`EAGAIN` again once no more frames are left.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-rs/-/merge_requests/1086>
