[FFmpeg-devel] [PATCH] doc/filters.texi: merge setdar and setsar documentation

Stefano Sabatini stefasab at gmail.com
Sat Jan 28 12:17:45 CET 2012


Most of the documentation is common to both filters, and I'm going to add
more shared docs. Factorize.
---
 doc/filters.texi |   60 +++++++++++++++++++++--------------------------------
 1 files changed, 24 insertions(+), 36 deletions(-)

diff --git a/doc/filters.texi b/doc/filters.texi
index 7d008bc..338632a 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -2323,10 +2323,10 @@ select='gte(t\,10)*lte(t\,20)*eq(pict_type\,I)'
 select='isnan(prev_selected_t)+gte(t-prev_selected_t\,10)'
 @end example
 
- at anchor{setdar}
- at section setdar
+ at section setdar, setsar
 
-Set the Display Aspect Ratio for the filter output video.
+The @code{setdar} filter sets the Display Aspect Ratio for the filter
+output video.
 
 This is done by changing the specified Sample (aka Pixel) Aspect
 Ratio, according to the following equation:
@@ -2337,12 +2337,23 @@ the video frame. Also the display aspect ratio set by this filter may
 be changed by later filters in the filterchain, e.g. in case of
 scaling or if another "setdar" or a "setsar" filter is applied.
 
-The filter accepts a parameter string which represents the wanted
-display aspect ratio.
-The parameter can be a floating point number string, or an expression
-of the form @var{num}:@var{den}, where @var{num} and @var{den} are the
-numerator and denominator of the aspect ratio.
-If the parameter is not specified, it is assumed the value "0:1".
+The @code{setsar} filter sets the Sample (aka Pixel) Aspect Ratio for
+the filter output video.
+
+Note that as a consequence of the application of this filter, the
+output display aspect ratio will change according to the equation
+above.
+
+Keep in mind that the sample aspect ratio set by this filter may be
+changed by later filters in the filterchain, e.g. if another "setsar"
+or a "setdar" filter is applied.
+
+The @code{setdar} and @code{setsar} filters accept a parameter string
+which represents the wanted display aspect ratio.  The parameter can
+be a floating point number string, or an expression of the form
+ at var{num}:@var{den}, where @var{num} and @var{den} are the numerator
+and denominator of the aspect ratio.  If the parameter is not
+specified, it is assumed the value "0:1".
 
 For example to change the display aspect ratio to 16:9, specify:
 @example
@@ -2351,7 +2362,10 @@ setdar=16:9
 setdar=1.77777
 @end example
 
-See also the @ref{setsar} filter documentation.
+For example to change the sample aspect ratio to 10:11, specify:
+ at example
+setsar=10:11
+ at end example
 
 @section setpts
 
@@ -2404,32 +2418,6 @@ setpts=N/(25*TB)
 setpts='1/(25*TB) * (N + 0.05 * sin(N*2*PI/25))'
 @end example
 
- at anchor{setsar}
- at section setsar
-
-Set the Sample (aka Pixel) Aspect Ratio for the filter output video.
-
-Note that as a consequence of the application of this filter, the
-output display aspect ratio will change according to the following
-equation:
- at math{DAR = HORIZONTAL_RESOLUTION / VERTICAL_RESOLUTION * SAR}
-
-Keep in mind that the sample aspect ratio set by this filter may be
-changed by later filters in the filterchain, e.g. if another "setsar"
-or a "setdar" filter is applied.
-
-The filter accepts a parameter string which represents the wanted
-sample aspect ratio.
-The parameter can be a floating point number string, or an expression
-of the form @var{num}:@var{den}, where @var{num} and @var{den} are the
-numerator and denominator of the aspect ratio.
-If the parameter is not specified, it is assumed the value "0:1".
-
-For example to change the sample aspect ratio to 10:11, specify:
- at example
-setsar=10:11
- at end example
-
 @section settb
 
 Set the timebase to use for the output frames timestamps.
-- 
1.7.5.4



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