lavfi/hue: apply major simplifications, and switch to AVOption-based system

This also drops support for "flat syntax" and "reinit" command.

"reinit" command is not very robust and complicates the logic more than
necessary, since requires to reset all the options in the command.

*This is a syntax break*.

1 files changed, 20 insertions, 31 deletions

diff --git a/doc/filters.texi b/doc/filters.texi
index 34383083e2..ee44b5f632 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -3653,24 +3653,27 @@ a float number which specifies chroma temporal strength, defaults to
 
 Modify the hue and/or the saturation of the input.
 
-This filter accepts the following optional named options:
+This filter accepts the following options:
 
 @table @option
 @item h
-Specify the hue angle as a number of degrees. It accepts a float
-number or an expression, and defaults to 0.0.
-
-@item H
-Specify the hue angle as a number of radians. It accepts a float
-number or an expression, and defaults to 0.0.
+Specify the hue angle as a number of degrees. It accepts an expression,
+and defaults to "0".
 
 @item s
 Specify the saturation in the [-10,10] range. It accepts a float number and
-defaults to 1.0.
+defaults to "1".
+
+@item H
+Specify the hue angle as a number of radians. It accepts a float
+number or an expression, and defaults to "0".
 @end table
 
-The @var{h}, @var{H} and @var{s} parameters are expressions containing the
-following constants:
+@option{h} and @option{H} are mutually exclusive, and can't be
+specified at the same time.
+
+The @option{h}, @option{H} and @option{s} option values are
+expressions containing the following constants:
 
 @table @option
 @item n
@@ -3689,10 +3692,6 @@ timestamp expressed in seconds, NAN if the input timestamp is unknown
 time base of the input video
 @end table
 
-The options can also be set using the syntax: @var{hue}:@var{saturation}
-
-In this case @var{hue} is expressed in degrees.
-
 @subsection Examples
 
 @itemize
@@ -3709,19 +3708,6 @@ hue=H=PI/2:s=1
 @end example
 
 @item
-Same command without named options, hue must be expressed in degrees:
-@example
-hue=90:1
-@end example
-
-@item
-Note that "h:s" syntax does not support expressions for the values of
-h and s, so the following example will issue an error:
-@example
-hue=PI/2:1
-@end example
-
-@item
 Rotate hue and make the saturation swing between 0
 and 2 over a period of 1 second:
 @example
@@ -3756,12 +3742,15 @@ hue="s=max(0\, min(1\, (START+DURATION-t)/DURATION))"
 
 This filter supports the following command:
 @table @option
-@item reinit
+@item s
+@item h
+@item H
 Modify the hue and/or the saturation of the input video.
-The command accepts the same named options and syntax than when calling the
-filter from the command-line.
+The command accepts the same options and syntax of the corresponding
+options.
 
-If a parameter is omitted, it is kept at its current value.
+If the specified expression is not valid, it is kept at its current
+value.
 @end table
 
 @section idet