From 1f75756c719442280590b97bf17f3eed7d6aa93d Mon Sep 17 00:00:00 2001 From: Lou Logan Date: Mon, 4 Jun 2018 16:38:20 -0800 Subject: [PATCH] doc/filters: mention required compile options for some filters Signed-off-by: Lou Logan --- doc/filters.texi | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/doc/filters.texi b/doc/filters.texi index 9f8fb74090..256ab42b00 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -3893,6 +3893,9 @@ not meant to be used directly. @section rubberband Apply time-stretching and pitch-shifting with librubberband. +To enable compilation of this filter, you need to configure FFmpeg with +@code{--enable-librubberband}. + The filter accepts the following options: @table @option @@ -11739,7 +11742,9 @@ Pass the video source unchanged to the output. @section ocr Optical Character Recognition -This filter uses Tesseract for optical character recognition. +This filter uses Tesseract for optical character recognition. To enable +compilation of this filter, you need to configure FFmpeg with +@code{--enable-libtesseract}. It accepts the following options: @@ -17143,7 +17148,8 @@ zoompan=z='min(max(zoom,pzoom)+0.0015,1.5)':d=1:x='iw/2-(iw/zoom/2)':y='ih/2-(ih @anchor{zscale} @section zscale Scale (resize) the input video, using the z.lib library: -https://github.com/sekrit-twc/zimg. +@url{https://github.com/sekrit-twc/zimg}. To enable compilation of this +filter, you need to configure FFmpeg with @code{--enable-libzimg}. The zscale filter forces the output display aspect ratio to be the same as the input, by changing the output sample aspect ratio.