avfilter: add displace video filter

Signed-off-by: Paul B Mahol <onemda@gmail.com>

1 files changed, 52 insertions, 0 deletions

diff --git a/doc/filters.texi b/doc/filters.texi
index 71f14567a1..47fd44d610 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -4750,6 +4750,58 @@ Flags to local 3x3 coordinates maps like this:
     6 7 8
 @end table
 
+@section displace
+
+Displace pixels as indicated by second and third input stream.
+
+It takes three input streams and outputs one stream, the first input is the
+source, and second and third input are displacement maps.
+
+The second input specifies how much to displace pixels along the
+x-axis, while the third input specifies how much to displace pixels
+along the y-axis.
+If one of displacement map streams terminates, last frame from that
+displacement map will be used.
+
+Note that once generated, displacements maps can be reused over and over again.
+
+A description of the accepted options follows.
+
+@table @option
+@item edge
+Set displace behavior for pixels that are out of range.
+
+Available values are:
+@table @samp
+@item blank
+Missing pixels are replaced by black pixels.
+
+@item smear
+Adjacent pixels will spread out to replace missing pixels.
+
+@item wrap
+Out of range pixels are wrapped so they point to pixels of other side.
+@end table
+Default is @samp{smear}.
+
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Add ripple effect to rgb input of video size hd720:
+@example
+ffmpeg -i INPUT -f lavfi -i nullsrc=s=hd720,lutrgb=128:128:128 -f lavfi -i nullsrc=s=hd720,geq='r=128+30*sin(2*PI*X/400+T):g=128+30*sin(2*PI*X/400+T):b=128+30*sin(2*PI*X/400+T)' -lavfi '[0][1][2]displace' OUTPUT
+@end example
+
+@item
+Add wave effect to rgb input of video size hd720:
+@example
+ffmpeg -i INPUT -f lavfi -i nullsrc=hd720,geq='r=128+80*(sin(sqrt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2))/220*2*PI+T)):g=128+80*(sin(sqrt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2))/220*2*PI+T)):b=128+80*(sin(sqrt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2))/220*2*PI+T))' -lavfi '[1]split[x][y],[0][x][y]displace' OUTPUT
+@end example
+@end itemize
+
 @section drawbox
 
 Draw a colored box on the input image.