diff --git a/doc/filters.texi b/doc/filters.texi index c64f899011..444949c660 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -2335,26 +2335,38 @@ select='gte(t\,10)*lte(t\,20)*eq(pict_type\,I)' select='isnan(prev_selected_t)+gte(t-prev_selected_t\,10)' @end example -@anchor{setdar} -@section setdar +@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: @math{DAR = HORIZONTAL_RESOLUTION / VERTICAL_RESOLUTION * SAR} -Keep in mind that this filter does not modify the pixel dimensions of -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. +Keep in mind that the @code{setdar} filter does not modify the pixel +dimensions of 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 the @code{setsar} +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 aspect ratio. The parameter can +be a floating point number string, an expression, or a string 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 display aspect ratio to 16:9, specify: @example @@ -2363,7 +2375,10 @@ setdar=16:9 setdar=1.77777 @end example -See also the @ref{setsar} filter documentation. +To change the sample aspect ratio to 10:11, specify: +@example +setsar=10:11 +@end example @section setpts @@ -2416,32 +2431,6 @@ setpts=N/(25*TB) setpts='1/(25*TB) * (N + 0.05 * sin(N*2*PI/25))' @end example -@anchor{setsar} -@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: -@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: -@example -setsar=10:11 -@end example - @section settb Set the timebase to use for the output frames timestamps.