[FFmpeg-cvslog] doc/filters: itemize examples for pad filter, and fix a few typos
Stefano Sabatini
git at videolan.org
Wed Aug 22 01:05:55 CEST 2012
ffmpeg | branch: master | Stefano Sabatini <stefasab at gmail.com> | Tue Aug 21 12:34:10 2012 +0200| [4a32b30e0cd906523564e77e6db2f92aca37a10c] | committer: Stefano Sabatini
doc/filters: itemize examples for pad filter, and fix a few typos
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=4a32b30e0cd906523564e77e6db2f92aca37a10c
---
doc/filters.texi | 55 ++++++++++++++++++++++++++++++++++++++----------------
1 file changed, 39 insertions(+), 16 deletions(-)
diff --git a/doc/filters.texi b/doc/filters.texi
index a9dbaf5..41f2d22 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -2795,36 +2795,59 @@ The default value of @var{color} is "black".
@end table
-Some examples follow:
+ at section Examples
+ at itemize
+ at item
+Add paddings with color "violet" to the input video. Output video
+size is 640x480, the top-left corner of the input video is placed at
+column 0, row 40:
@example
-# Add paddings with color "violet" to the input video. Output video
-# size is 640x480, the top-left corner of the input video is placed at
-# column 0, row 40.
pad=640:480:0:40:violet
+ at end example
-# pad the input to get an output with dimensions increased bt 3/2,
-# and put the input video at the center of the padded area
+ at item
+Pad the input to get an output with dimensions increased by 3/2,
+and put the input video at the center of the padded area:
+ at example
pad="3/2*iw:3/2*ih:(ow-iw)/2:(oh-ih)/2"
+ at end example
-# pad the input to get a squared output with size equal to the maximum
-# value between the input width and height, and put the input video at
-# the center of the padded area
+ at item
+Pad the input to get a squared output with size equal to the maximum
+value between the input width and height, and put the input video at
+the center of the padded area:
+ at example
pad="max(iw\,ih):ow:(ow-iw)/2:(oh-ih)/2"
+ at end example
-# pad the input to get a final w/h ratio of 16:9
+ at item
+Pad the input to get a final w/h ratio of 16:9:
+ at example
pad="ih*16/9:ih:(ow-iw)/2:(oh-ih)/2"
+ at end example
+
+ at item
+In case of anamorphic video, in order to set the output display aspect
+correctly, it is necessary to use @var{sar} in the expression,
+according to the relation:
+ at example
+(ih * X / ih) * sar = output_dar
+X = output_dar / sar
+ at end example
-# for anamorphic video, in order to set the output display aspect ratio,
-# it is necessary to use sar in the expression, according to the relation:
-# (ih * X / ih) * sar = output_dar
-# X = output_dar / sar
+Thus the previous example needs to be modified to:
+ at example
pad="ih*16/9/sar:ih:(ow-iw)/2:(oh-ih)/2"
+ at end example
-# double output size and put the input video in the bottom-right
-# corner of the output padded area
+ at item
+Double output size and put the input video in the bottom-right
+corner of the output padded area:
+ at example
pad="2*iw:2*ih:ow-iw:oh-ih"
@end example
+ at end itemize
@section pixdesctest
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