avfilter/vf_scdet: add filter to detect scene change

Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Limin Wang <lance.lmwang@gmail.com>

1 files changed, 35 insertions, 0 deletions

diff --git a/doc/filters.texi b/doc/filters.texi
index d19fd346ae..a3e78b1d20 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -16578,6 +16578,41 @@ Set the horizontal scrolling speed.
 Set the vertical scrolling speed.
 @end table
 
+@anchor{scdet}
+@section scdet
+
+Detect video scene change.
+
+This filter sets frame metadata with mafd between frame, the scene score, and
+forward the frame to the next filter, so they can use these metadata to detect
+scene change or others.
+
+In addition, this filter logs a message and sets frame metadata when it detects
+a scene change by @option{threshold}.
+
+@code{lavfi.scd.mafd} metadata keys are set with mafd for every frame.
+
+@code{lavfi.scd.score} metadata keys are set with scene change score for every frame
+to detect scene change.
+
+@code{lavfi.scd.time} metadata keys are set with current filtered frame time which
+detect scene change with @option{threshold}.
+
+The filter accepts the following options:
+
+@table @option
+@item threshold, t
+Set the scene change detection threshold as a percentage of maximum change. Good
+values are in the @code{[8.0, 14.0]} range. The range for @option{threshold} is
+@code{[0., 100.]}.
+
+Default value is @code{10.}.
+
+@item sc_pass, s
+Set the flag to pass scene change frames to the next filter. Default value is @code{0}
+You can enable it if you want to get snapshot of scene change frames only.
+@end table
+
 @anchor{selectivecolor}
 @section selectivecolor