doc/filters.texi: merge setdar and setsar documentation

Most of the documentation is common to both filters, and I'm going to add
more shared docs. Factorize.
This commit is contained in:
Stefano Sabatini 2012-01-24 23:28:26 +01:00
parent 70ffda3217
commit 3fa9ace3d8

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@ -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.