pflags=klass()
function pflags:init(o)
 self.speed = o.speed or 15
 self.len = o.len or 32
 self.noiz = o.noiz or 0
 self.buzz = o.buzz or 0
 self.detune = o.detune or 0
 self.reverb = o.reverb or 0
 self.dampen = o.dampen or 0
 self.editormode = o.editormode or 1
end

function pflags:validate()
 local speed,len,noiz,buzz,detune,reverb,dampen,editormode
  =self.speed,self.len,self.noiz,self.buzz,
   self.detune,self.reverb,self.dampen,self.editormode
 
 assert_range(speed,1,255,"speed")
 assert_range(len,1,33,"len")
 assert_range(noiz,0,2,"noiz")
 assert_range(buzz,0,2,"buzz")
 assert_range(detune,0,3,"detune")
 assert_range(reverb,0,3,"reverb")
 assert_range(dampen,0,3,"dampen")
 assert_range(editormode,0,2,"editormode")
end

function pflags:encode()
 local speed,len,noiz,buzz,detune,reverb,dampen,editormode
  =self.speed,self.len,self.noiz,self.buzz,
   self.detune,self.reverb,self.dampen,self.editormode

 speed &= 0xffff
 len &= 0xffff
 noiz &= 0xffff
 buzz &= 0xffff
 detune &= 0xffff
 reverb &= 0xffff
 dampen &= 0xffff
 editormode &= 0xffff

 self:validate()
 local byte0 = (
  dampen*72 +
  reverb*24 +
  detune*8 +
  buzz*4 +
  noiz*2 +
  editormode  -- "in editor mode" flag
 )
 return len | speed>>8 | byte0 >>16
end