[FFmpeg-devel] [PATCH] documentation: extend documentation for ffmpeg -aspect option

[Stefano Sabatini]

---
 doc/ffmpeg.texi |   13 ++++++++++++-
 1 files changed, 12 insertions(+), 1 deletions(-)

diff --git a/doc/ffmpeg.texi b/doc/ffmpeg.texi
index 47ed58b..9146297 100644
--- a/doc/ffmpeg.texi
+++ b/doc/ffmpeg.texi
@@ -232,7 +232,18 @@ The following abbreviations are recognized:
 @end table
 
 @item -aspect @var{aspect}
-Set aspect ratio (4:3, 16:9 or 1.3333, 1.7777).
+Set display aspect ratio for the output video.
+
+This option accepts in input a string of the form @var{num}:@var{den},
+where @var{num} and @var{den} are numerator and denominator of the
+wanted display aspect ratio, or @var{float}, where @var{float} is a
+floating number. For example "4:3", "16:9", "1.3333", or "1.7777" are
+valid values.
+
+If video filtering is enabled, the value set by the @code{-aspect}
+option overrides the display aspect ratio set at the end of the
+filterchain.
+
 @item -croptop @var{size}
 @item -cropbottom @var{size}
 @item -cropleft @var{size}
-- 
1.7.2.3