Filter thistogram
  Compute and draw a temporal histogram.
    Inputs:
       #0: default (video)
    Outputs:
       #0: default (video)
thistogram AVOptions:
  width             <int>        ..FV...... set width (from 0 to 8192) (default 0)
  w                 <int>        ..FV...... set width (from 0 to 8192) (default 0)
  display_mode      <int>        ..FV...... set display mode (from 0 to 2) (default stack)
     overlay         0            ..FV......
     parade          1            ..FV......
     stack           2            ..FV......
  d                 <int>        ..FV...... set display mode (from 0 to 2) (default stack)
     overlay         0            ..FV......
     parade          1            ..FV......
     stack           2            ..FV......
  levels_mode       <int>        ..FV...... set levels mode (from 0 to 1) (default linear)
     linear          0            ..FV......
     logarithmic     1            ..FV......
  m                 <int>        ..FV...... set levels mode (from 0 to 1) (default linear)
     linear          0            ..FV......
     logarithmic     1            ..FV......
  components        <int>        ..FV...... set color components to display (from 1 to 15) (default 7)
  c                 <int>        ..FV...... set color components to display (from 1 to 15) (default 7)
  bgopacity         <float>      ..FV...... set background opacity (from 0 to 1) (default 0.9)
  b                 <float>      ..FV...... set background opacity (from 0 to 1) (default 0.9)
  envelope          <boolean>    ..FV...... display envelope (default false)
  e                 <boolean>    ..FV...... display envelope (default false)
  ecolor            <color>      ..FV...... set envelope color (default "gold")
  ec                <color>      ..FV...... set envelope color (default "gold")
  slide             <int>        ..FV...... set slide mode (from 0 to 4) (default replace)
     frame           0            ..FV...... draw new frames
     replace         1            ..FV...... replace old columns with new
     scroll          2            ..FV...... scroll from right to left
     rscroll         3            ..FV...... scroll from left to right
     picture         4            ..FV...... display graph in single frame


