On some hardware the first few frames are bogus and not very useful.
Their timestamps are off, they have no timecodes, or there are spurious
black frames / no-signal frames. After a few frames this stabilizes
though.
https://bugzilla.gnome.org/show_bug.cgi?id=774850
Based on this we calculate the actual capture time, which should get us
rid of any capturing jitter by averaging it out.
Also add a output-stream-time property which forces the elements to
output the stream time directly instead of doing any conversion to the
pipeline clock. Use with care.
https://bugzilla.gnome.org/show_bug.cgi?id=774850
The hardware timestamps have no relation to when frames were produced,
only when frames arrived somewhere in the hardware. Especially there is
no guarantee that audio and video will have the same hardware timestamps
although they belong together, and even more important: the rate with
which the hardware timestamps increase is completely unrelated to the
rate with which the frames are captured!
As such we can as well use the pipeline clock directly and stop doing
complicated calculations. Also as a side effect this allows now running
without any pipeline clock, by directly making use of the stream times
as reported by the driver.
https://bugzilla.gnome.org/show_bug.cgi?id=774850
When a frame is found to not have an associated input source (cable
unplugged, wrong mode selected), an element warning will be issued. When
the next frame in the stream is found to have an input source selected
(e.g. cable replugged), an element info will be issued.
https://bugzilla.gnome.org/show_bug.cgi?id=774629
