Draw a colored box on the input image.
This filter accepts the following options:
- x, y
-
The expressions which specify the top left corner coordinates of the box. Default to 0.
- width, w, height, h
-
The expressions which specify the width and height of the box, if 0 they are interpreted as the input width and height. Default to 0.
- color, c
-
Specify the color of the box to write. For the general syntax of this option, check the "Color" section in the ffmpeg-utils manual. If the special value
invert
is used, the box edge color is the same as the video with inverted luma. - thickness, t
-
The expression which sets the thickness of the box edge. Default value is
3
.See below for the list of accepted constants.
The parameters for x, y, w and h and t are expressions containing the following constants:
- dar
-
The input display aspect ratio, it is the same as (w / h) * sar.
- hsub, vsub
-
horizontal and vertical chroma subsample values. For example for the pixel format "yuv422p" hsub is 2 and vsub is 1.
- in_h, ih, in_w, iw
-
The input width and height.
- sar
-
The input sample aspect ratio.
- x, y
-
The x and y offset coordinates where the box is drawn.
- w, h
-
The width and height of the drawn box.
- t
-
The thickness of the drawn box.
These constants allow the x, y, w, h and t expressions to refer to each other, so you may for example specify
y=x/dar
orh=w/dar
.
Examples
-
Draw a black box around the edge of the input image:
drawbox
-
Draw a box with color red and an opacity of 50%:
drawbox=10:20:200:60:red@0.5
The previous example can be specified as:
drawbox=x=10:y=20:w=200:h=60:color=red@0.5
-
Fill the box with pink color:
drawbox=x=10:y=10:w=100:h=100:color=pink@0.5:t=max
-
Draw a 2-pixel red 2.40:1 mask:
drawbox=x=-t:y=0.5*(ih-iw/2.4)-t:w=iw+t*2:h=iw/2.4+t*2:t=2:c=red