Convert input audio to a video output, displaying the audio phase.

The filter accepts the following options:

rate, r

Set the output frame rate. Default value is 25.

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 800x400.

rc, gc, bc

Specify the red, green, blue contrast. Default values are 2, 7 and 1. Allowed range is [0, 255].

mpc

Set color which will be used for drawing median phase. If color is none which is default, no median phase value will be drawn.

The filter also exports the frame metadata lavfi.aphasemeter.phase which represents mean phase of current audio frame. Value is in range [-1, 1]. The -1 means left and right channels are completely out of phase and 1 means channels are in phase.