Filter aphasemeter
  Convert input audio to phase meter video output.
    Inputs:
       #0: default (audio)
    Outputs:
        dynamic (depending on the options)
aphasemeter AVOptions:
  rate              <video_rate> ..FV..... set video rate (default "25")
  r                 <video_rate> ..FV..... set video rate (default "25")
  size              <image_size> ..FV..... set video size (default "800x400")
  s                 <image_size> ..FV..... set video size (default "800x400")
  rc                <int>        ..FV..... set red contrast (from 0 to 255) (default 2)
  gc                <int>        ..FV..... set green contrast (from 0 to 255) (default 7)
  bc                <int>        ..FV..... set blue contrast (from 0 to 255) (default 1)
  mpc               <string>     ..FV..... set median phase color (default "none")
  video             <boolean>    ..FV..... set video output (default true)


