Convert input audio to a video output, representing the audio vector scope.

The filter is used to measure the difference between channels of stereo audio stream. A monoaural signal, consisting of identical left and right signal, results in straight vertical line. Any stereo separation is visible as a deviation from this line, creating a Lissajous figure. If the straight (or deviation from it) but horizontal line appears this indicates that the left and right channels are out of phase.

The filter accepts the following options:

mode, m

Set the vectorscope mode.

Available values are:

lissajous

Lissajous rotated by 45 degrees.

lissajous_xy

Same as above but not rotated.

polar

Shape resembling half of circle.

Default value is lissajous.

size, s

Set the video size for the output. For the syntax of this option, check the "Video size" section in the ffmpeg-utils manual. Default value is 400x400.

rate, r

Set the output frame rate. Default value is 25.

rc, gc, bc, ac

Specify the red, green, blue and alpha contrast. Default values are 40, 160, 80 and 255. Allowed range is [0, 255].

rf, gf, bf, af

Specify the red, green, blue and alpha fade. Default values are 15, 10, 5 and 5. Allowed range is [0, 255].

zoom

Set the zoom factor. Default value is 1. Allowed range is [1, 10].

draw

Set the vectorscope drawing mode.

Available values are:

dot

Draw dot for each sample.

line

Draw line between previous and current sample.

Default value is dot.