Allows any samplerate and make it negotiable. Fixing a scenario
where transcriberbin is configured with passthrough enabled,
(and negotiated samplerate is not supported by transcriber)
and then setting passthrough=false later during playback.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-rs/-/merge_requests/1287>
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/1211>
If a basicna character is received, it will always have a channel of 0
even if it's directed at a different data channel. Fix by keeping track
of the last channel from other commands and using that when producing
text in the basicna subset.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-rs/-/merge_requests/1112>
With this, if the transcriber element in use supports "translation_src_"
request source pads, the user can now specify what languages to
translate to and how to map them to 608 channels (only CC1 and CC3 are
supported).
For instance, translation-languages="languages, CC3=transcript, CC1=fr"
will cause the original transcript to be muxed into the CC3 channel, and
the French translation to be muxed into the CC1 channel.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-rs/-/merge_requests/1149>
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/1147>
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/1146>
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/1142>
