iamaaditya · September 2, 2012 13:38 · Apr 18, 2010
diff --git a/specturm.py b/specturm.py
@@ -0,0 +1,57 @@
+import ossaudiodev as oss
+from numpy import fft
+import math
+import pygame
+import pygame.surfarray as surfarray
+
+
+d = oss.open('rw')
+d.setfmt(oss.AFMT_U16_LE)
+d.channels(1)
+d.speed (44100)
+
+buf_size = 4096
+bins = 256
+
+WIDTH = 500
+
+pygame.init()
+screen = pygame.display.set_mode((WIDTH, bins))
+surf = pygame.display.get_surface()
+px = surfarray.pixels2d(surf)
+
+
+def power(c):
+    return c.real * c.real + c.imag * c.imag
+
+X = 0
+
+while 1:
+    x = d.read(buf_size)
+    v = [-0.5 + (ord(x[2*i]) | ord(x[2*i+1])<<8) / 65536.0 for i in range(0,len(x)/2)]
+    f = fft.fft(v)
+    p = [power(c) for c in f]
+
+    b = [0] * bins
+    for i in range(0,bins):
+        for j in range(0,buf_size/(4*bins)):
+            b[i] += p[buf_size * i / (4*bins) + j]
+
+    Xn = (X+1) % WIDTH
+
+    for i in range(0,bins):
+        k = int(255 * math.log(b[i]+1))
+        if (k >= 255):
+            k = 255
+        px[X,bins-i-1] = k << 8
+        k = 64
+        px[Xn,bins-i-1] = (k<<16) | (k<<8) | k
+
+    surfarray.blit_array(surf, px)
+
+    pygame.display.flip()
+
+    X += 1
+    if (X >= WIDTH):
+        X = 0
+    d.write(x)