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
and255
. Allowed range is[0, 255]
. - rf, gf, bf, af
-
Specify the red, green, blue and alpha fade. Default values are
15
,10
,5
and5
. Allowed range is[0, 255]
. - zoom
-
Set the zoom factor. Default value is
1
. Allowed range is[1, 10]
.
Examples
-
Complete example using ffplay:
ffplay -f lavfi 'amovie=input.mp3, asplit [a][out1]; [a] avectorscope=zoom=1.3:rc=2:gc=200:bc=10:rf=1:gf=8:bf=7 [out0]'