[FFmpeg-devel] [PATCH] doc/filters: add geq gradient examples
Lou Logan
lou at lrcd.com
Tue Sep 16 04:56:29 CEST 2014
Radial gradient by Víctor Paesa.
Linear gradient by Paul Gentemann.
Also-by: Víctor Paesa <victorpaesa at googlemail.com>
Also-by: Paul Gentemann <beriukay at gmail.com>
Signed-off-by: Lou Logan <lou at lrcd.com>
---
doc/filters.texi | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/doc/filters.texi b/doc/filters.texi
index bb486ea..5a7ad58 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -5124,6 +5124,19 @@ Modify RGB components depending on pixel position:
@example
geq=r='X/W*r(X,Y)':g='(1-X/W)*g(X,Y)':b='(H-Y)/H*b(X,Y)'
@end example
+
+ at item
+Create a radial gradient that is the same size as the input:
+ at example
+geq=lum=255*gauss((X/W-0.5)*3)*gauss((Y/H-0.5)*3)/gauss(0)/gauss(0),format=gray
+ at end example
+
+ at item
+Create a linear gradient to use as a mask for another filter, then
+compose with @ref{overlay}:
+ at example
+geq=lum=255*(Y/H),format=gray[grad];[0:v]boxblur=4[blur];[blur][grad]alphamerge[alpha];[0:v][alpha]overlay
+ at end example
@end itemize
@section gradfun
--
2.1.0
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