experiment with audio visualization

audio.py

@@ -0,0 +1,77 @@
+#!/usr/bin/env python3
+
+# ----------------------------------------------------------------------------
+# "THE BEER-WARE LICENSE" (Revision 42):
+# <xythobuz@xythobuz.de> wrote this file.  As long as you retain this notice
+# you can do whatever you want with this stuff. If we meet some day, and you
+# think this stuff is worth it, you can buy me a beer in return.   Thomas Buck
+# ----------------------------------------------------------------------------
+
+import time
+import pyaudio
+import numpy as np
+
+class AudioVisualizer:
+    def __init__(self, g, f = 20, t = 60.0):
+        self.gui = g
+        self.interval = 1.0 / f
+        self.timeout = t
+
+        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)
+        print(self.s)
+
+    def restart(self):
+        self.data = self.init()
+        self.start = time.time()
+
+    def finished(self):
+        if (time.time() - self.start) >= self.timeout:
+            return True
+        return FALSE
+
+    def draw_line(self, x, val, y_off):
+        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)
+        for y in range(0, int(h)):
+            self.gui.set_pixel(x, y_off + (32 - y), (255, 255, 255))
+
+    def draw(self):
+        frames = self.s.read(self.chunk)
+
+        left = frames[::4] # start from first left sample (index 0), skip 4 bytes (2 * 2, int16 and stereo)
+        left = np.frombuffer(left, dtype=np.int16)
+
+        right = frames[2::4] # start from first right sample (index 2), skip 4 bytes
+        right = np.frombuffer(right, dtype=np.int16)
+
+        if self.do_fft:
+            # FFT
+            left = np.fft.fft(left)
+            right = np.fft.fft(right)
+
+        # average down to fit screen
+        m = self.chunk / 2 / self.gui.width # stereo
+        left = left.reshape(-1, int(m)).mean(axis=1)
+        right = right.reshape(-1, int(m)).mean(axis=1)
+
+        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)
+            else:
+                self.draw_line(x, left[x], 0)
+                self.draw_line(x, right[x], self.gui.height / 2)
+
+if __name__ == "__main__":
+    import util
+    i = util.getInput()
+    t = util.getTarget(i)
+    a = AudioVisualizer(t)
+    util.loop(t, a.draw)