[FFmpeg-devel] [PATCH] doc/filters: add geq gradient examples

[Clément Bœsch]

On Mon, Sep 15, 2014 at 06:56:29PM -0800, Lou Logan wrote:
> 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
> +

You may mention @ref{vignette} filter here so people don't end up using it
verbatim.

> + 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

This filtergraph is complex and very input dependant; please provide a
complete command line as an example

> + at end example
>  @end itemize
>  
>  @section gradfun
> -- 
> 2.1.0
> 

-- 
Clément B.
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