demo

py/playwav.py

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+#!/usr/bin/env python
+
+# Simple test script that plays (some) wav files
+
+from __future__ import print_function
+
+import sys
+import wave
+import getopt
+import alsaaudio
+
+def play(device, f):    
+
+    print('%d channels, %d sampling rate\n' % (f.getnchannels(),
+                                               f.getframerate()))
+    # Set attributes
+    device.setchannels(f.getnchannels())
+    device.setrate(f.getframerate())
+
+    # 8bit is unsigned in wav files
+    if f.getsampwidth() == 1:
+        device.setformat(alsaaudio.PCM_FORMAT_U8)
+    # Otherwise we assume signed data, little endian
+    elif f.getsampwidth() == 2:
+        device.setformat(alsaaudio.PCM_FORMAT_S16_LE)
+    elif f.getsampwidth() == 3:
+        device.setformat(alsaaudio.PCM_FORMAT_S24_3LE)
+    elif f.getsampwidth() == 4:
+        device.setformat(alsaaudio.PCM_FORMAT_S32_LE)
+    else:
+        raise ValueError('Unsupported format')
+
+    periodsize = f.getframerate() // 8
+
+    device.setperiodsize(periodsize)
+    
+    data = f.readframes(periodsize)
+    while data:
+        # Read data from stdin
+        device.write(data)
+        data = f.readframes(periodsize)
+
+
+def usage():
+    print('usage: playwav.py [-d <device>] <file>', file=sys.stderr)
+    sys.exit(2)
+
+if __name__ == '__main__':
+
+    device = 'default'
+
+    opts, args = getopt.getopt(sys.argv[1:], 'd:')
+    for o, a in opts:
+        if o == '-d':
+            device = a
+
+    if not args:
+        usage()
+        
+    f = wave.open(args[0], 'rb')
+    device = alsaaudio.PCM(device=device)
+
+    play(device, f)
+
+    f.close()