Lib/lib-stdwin/Soundogram.py

   1 # Module 'Soundogram'
   2
   3 import audio
   4 from Histogram import Histogram
   5
   6 class Soundogram(Histogram):
   7         #
   8         def define(self, win, chunk):
   9                 width, height = corner = win.getwinsize()
  10                 bounds = (0, 0), corner
  11                 self.chunk = chunk
  12                 self.step = (len(chunk)-1)/(width/2+1) + 1
  13                 ydata = _make_ydata(chunk, self.step)
  14                 return Histogram.define(self, (win, bounds, ydata, (0, 128)))
  15         #
  16         def setchunk(self, chunk):
  17                 self.chunk = chunk
  18                 self.recompute()
  19         #
  20         def recompute(self):
  21                 (left, top), (right, bottom) = self.bounds
  22                 width = right - left
  23                 self.step = (len(chunk)-1)/width + 1
  24                 ydata = _make_ydata(chunk, self.step)
  25                 self.setdata(ydata, (0, 128))
  26         #
  27
  28
  29 def _make_ydata(chunk, step):
  30         ydata = []
  31         for i in range(0, len(chunk), step):
  32                 piece = audio.chr2num(chunk[i:i+step])
  33                 mi, ma = min(piece), max(piece)
  34                 y = max(abs(mi), abs(ma))
  35                 ydata.append(y)
  36         return ydata