[FFmpeg-trac] #2495(documentation:new): Better filter help

[FFmpeg]

#2495: Better filter help
-------------------------------------+-------------------------------------
             Reporter:  jbvsmo       |                     Type:
               Status:  new          |  enhancement
            Component:               |                 Priority:  wish
  documentation                      |                  Version:  git-
             Keywords:               |  master
             Blocking:               |               Blocked By:
Analyzed by developer:  0            |  Reproduced by developer:  0
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 Is it possible to add default values of filters in the help option? Also,
 some data is missing, like ranges in options that accept expressions.


 This is the help for e.g. Hue filter:
 {{{
 hue AVOptions:
   h       <string>     ..FV.. set the hue angle degrees expression
   s       <string>     ..FV.. set the saturation expression
   H       <string>     ..FV.. set the hue angle radians expression
 }}}


 While this is the man page (despite not being updated and show "float"
 instead of "expression", it has the range information and default value):
 {{{

 hue
    Modify the hue and/or the saturation of the input.
    This filter accepts the following options:
    h   Specify the hue angle as a number of degrees. It accepts an
 expression, and defaults to "0".
    s   Specify the saturation in the [-10,10] range. It accepts a float
 number and defaults to "1".
    H   Specify the hue angle as a number of radians. It accepts a float
 number or an expression, and defaults to "0".
 }}}


 The filter options that take int or double do have the range, but not the
 default value. E.g:
 {{{
 c1_strength   <int>    ..FV.. set component #1 strength (from 0 to 100)
 }}}


 So, it would be nice to have these values in the help option because they
 will not suffer from code changes (because the values come from the code)
 and are easier to use. Example:

 {{{
 hue AVOptions:
   h    <string>   ..FV.. set the hue angle degrees expression (default: 0)
   s    <string>   ..FV.. set the saturation expression (from -10 to 10,
 default: 1)
   H    <string>   ..FV.. set the hue angle radians expression (default: 0)
 }}}

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/2495>
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