Merge remote-tracking branch 'qatar/master'

* qatar/master:
  FATE: add a test for the interlace filter
  lavfi: new interlace filter

Conflicts:
	Changelog
	configure
	doc/filters.texi
	libavfilter/Makefile
	libavfilter/allfilters.c
	tests/fate/filter.mak

Merged-by: Michael Niedermayer <michaelni@gmx.at>

1 files changed, 30 insertions, 0 deletions

diff --git a/doc/filters.texi b/doc/filters.texi
index a10d2fc8aa..419b0f39be 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -3774,6 +3774,36 @@ Default value is @code{none}.
 Swap luma/chroma/alpha fields. Exchange even & odd lines. Default value is @code{0}.
 @end table
 
+@section interlace
+
+Simple interlacing filter from progressive contents. This interleaves upper (or
+lower) lines from odd frames with lower (or upper) lines from even frames,
+halving the frame rate and preserving image height.
+
+@example
+   Original        Original             New Frame
+   Frame 'j'      Frame 'j+1'             (tff)
+  ==========      ===========       ==================
+    Line 0  -------------------->    Frame 'j' Line 0
+    Line 1          Line 1  ---->   Frame 'j+1' Line 1
+    Line 2 --------------------->    Frame 'j' Line 2
+    Line 3          Line 3  ---->   Frame 'j+1' Line 3
+     ...             ...                   ...
+New Frame + 1 will be generated by Frame 'j+2' and Frame 'j+3' and so on
+@end example
+
+It accepts the following optional parameters:
+
+@table @option
+@item scan
+determines whether the interlaced frame is taken from the even (tff - default)
+or odd (bff) lines of the progressive frame.
+
+@item lowpass
+Enable (default) or disable the vertical lowpass filter to avoid twitter
+interlacing and reduce moire patterns.
+@end table
+
 @section kerndeint
 
 Deinterlace input video by applying Donald Graft's adaptive kernel