On Tue, 16 Sep 2014 07:34:14 +0200, Clément Bœsch wrote: > On Mon, Sep 15, 2014 at 06:56:29PM -0800, Lou Logan wrote: > > +@item > > +Create a radial gradient that is the same size as the input: > > +@example > > +geq=lum=255*gauss((X/W-0.5)*3)*gauss((Y/H-0.5)*3)/gauss(0)/gauss(0),format=gray > > +@end example > > + > > You may mention @ref{vignette} filter here so people don't end up using it > verbatim.
Mentioned. > > +@item > > +Create a linear gradient to use as a mask for another filter, then > > +compose with @ref{overlay}: > > +@example > > +geq=lum=255*(Y/H),format=gray[grad];[0:v]boxblur=4[blur];[blur][grad]alphamerge[alpha];[0:v][alpha]overlay > > This filtergraph is complex and very input dependant; please provide a > complete command line as an example Added. I actually prefer complete examples. New version inserted below: From 3ec5557f7ffd4e2ce6ddc5c06d1e5d5d07013536 Mon Sep 17 00:00:00 2001 From: Lou Logan <l...@lrcd.com> Date: Mon, 15 Sep 2014 18:07:09 -0800 Subject: [PATCH] doc/filters: add geq gradient examples MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Radial gradient by Víctor Paesa. Linear gradient by Paul Gentemann. Also-by: Víctor Paesa <victorpa...@googlemail.com> Also-by: Paul Gentemann <beriu...@gmail.com> Signed-off-by: Lou Logan <l...@lrcd.com> --- doc/filters.texi | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/doc/filters.texi b/doc/filters.texi index bb486ea..1881b5c 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -5124,6 +5124,20 @@ 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 + +@item +Create a radial gradient that is the same size as the input (also see +the @ref{vignette} filter): +@example +geq=lum=255*gauss((X/W-0.5)*3)*gauss((Y/H-0.5)*3)/gauss(0)/gauss(0),format=gray +@end example + +@item +Create a linear gradient to use as a mask for another filter, then +compose with @ref{overlay}: +@example +ffmpeg -i input.mp4 -filter_complex "geq=lum=255*(Y/H),format=gray[grad];[0:v]boxblur=4[blur];[blur][grad]alphamerge[alpha];[0:v][alpha]overlay" output.mp4 +@end example @end itemize @section gradfun -- 2.1.0 _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel