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 an expression and defaults to "1".
- H
-
Specify the hue angle as a number of radians. It accepts an expression, and defaults to "0".
- b
-
Specify the brightness in the [-10,10] range. It accepts an expression and defaults to "0".
h and H are mutually exclusive, and can’t be specified at the same time.
The b, h, H and s option values are expressions containing the following constants:
- n
-
frame count of the input frame starting from 0
- pts
-
presentation timestamp of the input frame expressed in time base units
- r
-
frame rate of the input video, NAN if the input frame rate is unknown
- t
-
timestamp expressed in seconds, NAN if the input timestamp is unknown
- tb
-
time base of the input video
Examples
-
Set the hue to 90 degrees and the saturation to 1.0:
hue=h=90:s=1
-
Same command but expressing the hue in radians:
hue=H=PI/2:s=1
-
Rotate hue and make the saturation swing between 0 and 2 over a period of 1 second:
hue="H=2*PI*t: s=sin(2*PI*t)+1"
-
Apply a 3 seconds saturation fade-in effect starting at 0:
hue="s=min(t/3\,1)"
The general fade-in expression can be written as:
hue="s=min(0\, max((t-START)/DURATION\, 1))"
-
Apply a 3 seconds saturation fade-out effect starting at 5 seconds:
hue="s=max(0\, min(1\, (8-t)/3))"
The general fade-out expression can be written as:
hue="s=max(0\, min(1\, (START+DURATION-t)/DURATION))"
Commands
This filter supports the following commands:
- b, s, h, H
-
Modify the hue and/or the saturation and/or brightness of the input video. The command accepts the same syntax of the corresponding option.
If the specified expression is not valid, it is kept at its current value.