Filter afir
  Apply Finite Impulse Response filter with supplied coefficients in additional stream(s).
    slice threading supported
    Inputs:
        dynamic (depending on the options)
    Outputs:
        dynamic (depending on the options)
afir AVOptions:
  dry               <float>      ..F.A..... set dry gain (from 0 to 10) (default 1)
  wet               <float>      ..F.A..... set wet gain (from 0 to 10) (default 1)
  length            <float>      ..F.A..... set IR length (from 0 to 1) (default 1)
  gtype             <int>        ..F.A..... set IR auto gain type (from -1 to 2) (default peak)
     none            -1           ..F.A..... without auto gain
     peak            0            ..F.A..... peak gain
     dc              1            ..F.A..... DC gain
     gn              2            ..F.A..... gain to noise
  irgain            <float>      ..F.A..... set IR gain (from 0 to 1) (default 1)
  irfmt             <int>        ..F.A..... set IR format (from 0 to 1) (default input)
     mono            0            ..F.A..... single channel
     input           1            ..F.A..... same as input
  maxir             <float>      ..F.A..... set max IR length (from 0.1 to 60) (default 30)
  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")
  minp              <int>        ..F.A..... set min partition size (from 1 to 32768) (default 8192)
  maxp              <int>        ..F.A..... set max partition size (from 8 to 32768) (default 8192)
  nbirs             <int>        ..F.A..... set number of input IRs (from 1 to 32) (default 1)
  ir                <int>        ..F.A....T select IR (from 0 to 31) (default 0)


