more fft testing. still not happy with the results.

audio.py

@@ -12,13 +12,13 @@ import pyaudio
 import numpy as np
 
 class AudioVisualizer:
-    def __init__(self, g, f = 20, t = 60.0):
+    def __init__(self, g, f = 20, t = 60.0, fft = True):
         self.gui = g
         self.interval = 1.0 / f
         self.timeout = t
+        self.do_fft = fft
 
         self.chunk = 1024 * 2 # stereo
-        self.do_fft = False
 
         self.p = pyaudio.PyAudio()
         self.s = self.p.open(format=pyaudio.paInt16, channels=2, rate=44100, input=True)
@@ -37,11 +37,30 @@ class AudioVisualizer:
         h = int(val) / 32768.0 * self.gui.height / 2
         self.gui.set_pixel(x, y_off + (16 - h), (255, 255, 255))
 
-    def draw_bar(self, x, val, y_off):
-        h = int(val) / (32768.0 * 2) * (self.gui.height / 2)
+    def draw_bar(self, x, val, y_off, max_val):
+        if max_val <= 0.0:
+            max_val = 1.0
+        h = int(val) / float(max_val) * self.gui.height / 2
         for y in range(0, int(h)):
             self.gui.set_pixel(x, y_off + (32 - y), (255, 255, 255))
 
+    # stolen from https://github.com/aiXander/Realtime_PyAudio_FFT/blob/master/src/fft.py
+    def calc_fft(self, data):
+        data = data * np.hamming(len(data))
+        try:
+            fft = np.abs(np.fft.rfft(data)[1:])
+        except:
+            fft = np.fft.fft(data)
+            left, right = np.split(np.abs(fft), 2)
+            fft = np.add(left, right[::-1])
+
+        #try:
+        #    fft = np.multiply(20, np.log10(fft))
+        #except:
+        #    pass
+
+        return fft
+
     def draw(self):
         frames = self.s.read(self.chunk)
 
@@ -53,18 +72,23 @@ class AudioVisualizer:
 
         if self.do_fft:
             # FFT
-            left = np.fft.fft(left)
-            right = np.fft.fft(right)
+            left = self.calc_fft(left)
+            right = self.calc_fft(right)
 
         # average down to fit screen
         m = self.chunk / 2 / self.gui.width # stereo
+        if self.do_fft:
+            m = m / 2
         left = left.reshape(-1, int(m)).mean(axis=1)
         right = right.reshape(-1, int(m)).mean(axis=1)
 
+        l_max = max(left)
+        r_max = max(right)
+
         for x in range(0, self.gui.width):
             if self.do_fft:
-                self.draw_bar(x, left[x], 0)
-                self.draw_bar(x, right[x], self.gui.height / 2)
+                self.draw_bar(x, left[x], 0, l_max)
+                self.draw_bar(x, right[x], self.gui.height / 2, r_max)
             else:
                 self.draw_line(x, left[x], 0)
                 self.draw_line(x, right[x], self.gui.height / 2)