This was required by vf_pp, which was just removed.
vf_dlopen has this stuff in its API. This API is considered stable, so
the related fields are not removed from it. But the fields are always 0
now, so there's no point in keeping the example program around.
vf_pullup.c did some extremely awkward passthrough of this information,
but didn't actually use it.
For quiet mode: ILDETECT_QUIET=1 ildetect.sh ...
Telecine decision (guess by ildetect.so) is verified by retrying the
ildetect run with the pullup filter inserted.
When the first frame of a telecine pattern did not generate an output
frame (because it is a 0 or a 1), this could lead to the first two
output frames getting equal pts values.
When the first frame of a telecine pattern generates exactly one output
frame (i.e. when the telecine pattern starts with 2 or 3), then the
output was correct before this comment, and still is unchanged.
When the first frame of a telecine pattern generates more than one
output frame (i.e. when it starts with 4 to 9), then output pts are
still broken. This is not really solvable without knowing the frame
duration, or delaying output by one frame.
This is done by requesting a buffer from the next filter in the chain, instead
of always allocating our own. This allows the next filter to e.g. ensure its
own preferred memory layout.
