Filter aiir
  Apply Infinite Impulse Response filter with supplied coefficients.
    slice threading supported
    Inputs:
       #0: default (audio)
    Outputs:
        dynamic (depending on the options)
aiir AVOptions:
  zeros             <string>     ..F.A..... set B/numerator/zeros/reflection coefficients (default "1+0i 1-0i")
  z                 <string>     ..F.A..... set B/numerator/zeros/reflection coefficients (default "1+0i 1-0i")
  poles             <string>     ..F.A..... set A/denominator/poles/ladder coefficients (default "1+0i 1-0i")
  p                 <string>     ..F.A..... set A/denominator/poles/ladder coefficients (default "1+0i 1-0i")
  gains             <string>     ..F.A..... set channels gains (default "1|1")
  k                 <string>     ..F.A..... set channels gains (default "1|1")
  dry               <double>     ..F.A..... set dry gain (from 0 to 1) (default 1)
  wet               <double>     ..F.A..... set wet gain (from 0 to 1) (default 1)
  format            <int>        ..F.A..... set coefficients format (from -2 to 4) (default zp)
     ll              -2           ..F.A..... lattice-ladder function
     sf              -1           ..F.A..... analog transfer function
     tf              0            ..F.A..... digital transfer function
     zp              1            ..F.A..... Z-plane zeros/poles
     pr              2            ..F.A..... Z-plane zeros/poles (polar radians)
     pd              3            ..F.A..... Z-plane zeros/poles (polar degrees)
     sp              4            ..F.A..... S-plane zeros/poles
  f                 <int>        ..F.A..... set coefficients format (from -2 to 4) (default zp)
     ll              -2           ..F.A..... lattice-ladder function
     sf              -1           ..F.A..... analog transfer function
     tf              0            ..F.A..... digital transfer function
     zp              1            ..F.A..... Z-plane zeros/poles
     pr              2            ..F.A..... Z-plane zeros/poles (polar radians)
     pd              3            ..F.A..... Z-plane zeros/poles (polar degrees)
     sp              4            ..F.A..... S-plane zeros/poles
  process           <int>        ..F.A..... set kind of processing (from 0 to 2) (default s)
     d               0            ..F.A..... direct
     s               1            ..F.A..... serial
     p               2            ..F.A..... parallel
  r                 <int>        ..F.A..... set kind of processing (from 0 to 2) (default s)
     d               0            ..F.A..... direct
     s               1            ..F.A..... serial
     p               2            ..F.A..... parallel
  precision         <int>        ..F.A..... set filtering precision (from 0 to 3) (default dbl)
     dbl             0            ..F.A..... double-precision floating-point
     flt             1            ..F.A..... single-precision floating-point
     i32             2            ..F.A..... 32-bit integers
     i16             3            ..F.A..... 16-bit integers
  e                 <int>        ..F.A..... set precision (from 0 to 3) (default dbl)
     dbl             0            ..F.A..... double-precision floating-point
     flt             1            ..F.A..... single-precision floating-point
     i32             2            ..F.A..... 32-bit integers
     i16             3            ..F.A..... 16-bit integers
  normalize         <boolean>    ..F.A..... normalize coefficients (default true)
  n                 <boolean>    ..F.A..... normalize coefficients (default true)
  mix               <double>     ..F.A..... set mix (from 0 to 1) (default 1)
  response          <boolean>    ..FV...... show IR frequency response (default false)
  channel           <int>        ..FV...... set IR channel to display frequency response (from 0 to 1024) (default 0)
  size              <image_size> ..FV...... set video size (default "hd720")
  rate              <video_rate> ..FV...... set video rate (default "25")


