[FFmpeg-cvslog] doc/filters: add scale2ref example for proportional scaling

[Gyan Doshi]

ffmpeg | branch: master | Gyan Doshi <ffmpeg at gyani.pro> | Mon May 13 22:16:19 2019 +0530| [21832b93d53312fa43b40de73d44805bdacaab26] | committer: Gyan Doshi

doc/filters: add scale2ref example for proportional scaling

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=21832b93d53312fa43b40de73d44805bdacaab26
---

 doc/filters.texi | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/doc/filters.texi b/doc/filters.texi
index d231387d59..0683f7bff5 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -15316,6 +15316,12 @@ Scale a subtitle stream (b) to match the main video (a) in size before overlayin
 @example
 'scale2ref[b][a];[a][b]overlay'
 @end example
+
+ at item
+Scale a logo to 1/10th the height of a video, while preserving its display aspect ratio.
+ at example
+[logo-in][video-in]scale2ref=w=oh*mdar:h=ih/10[logo-out][video-out]
+ at end example
 @end itemize
 
 @anchor{selectivecolor}