This is release 0.4; it was tested with python2.5 and python3.0 (rc2 &

3)


git-svn-id: svn://svn.code.sf.net/p/pyalsaaudio/code/trunk@29 ec2f30ec-7544-0410-870e-f70ca00c83f0

recordtest.py

@@ -1,3 +1,5 @@
+#!/usr/bin/env python
+
 ## recordtest.py
 ##
 ## This is an example of a simple sound capture script.
@@ -7,39 +9,62 @@
 ## writing the data to standard out.
 ##
 ## To test it out do the following:
-## python recordtest.py > out.raw # talk to the microphone
+## python recordtest.py out.raw # talk to the microphone
 ## aplay -r 8000 -f S16_LE -c 1 out.raw
 
-import alsaaudio
+
+# Footnote: I'd normally use print instead of sys.std(out|err).write,
+# but we're in the middle of the conversion between python 2 and 3
+# and this code runs on both versions without conversion
+
 import sys
 import time
+import getopt
+import alsaaudio
 
-# Open the device in nonblocking capture mode. The last argument could
-# just as well have been zero for blocking mode. Then we could have
-# left out the sleep call in the bottom of the loop
-inp = alsaaudio.PCM(alsaaudio.PCM_CAPTURE,alsaaudio.PCM_NONBLOCK)
+def usage():
+    sys.stderr.write('usage: recordtest.py [-c <card>] <file>\n')
+    sys.exit(2)
 
-# Set attributes: Mono, 8000 Hz, 16 bit little endian samples
-inp.setchannels(1)
-inp.setrate(8000)
-inp.setformat(alsaaudio.PCM_FORMAT_S16_LE)
+if __name__ == '__main__':
 
-# The period size controls the internal number of frames per period.
-# The significance of this parameter is documented in the ALSA api.
-# For our purposes, it is suficcient to know that reads from the device
-# will return this many frames. Each frame being 2 bytes long.
-# This means that the reads below will return either 320 bytes of data
-# or 0 bytes of data. The latter is possible because we are in nonblocking
-# mode.
-inp.setperiodsize(160)
+    card = 'default'
 
-loops = 1000000
-while loops > 0:
-  loops -= 1
-  # Read data from device
-  l,data = inp.read()
-  
-  if l:
-    # actual data read. Write it to stdout
-    sys.stdout.write(data)
-  time.sleep(.001)
+    opts, args = getopt.getopt(sys.argv[1:], 'c:')
+    for o, a in opts:
+        if o == '-c':
+            card = a
+
+    if not args:
+        usage()
+
+    f = open(args[0], 'wb')
+
+    # Open the device in nonblocking capture mode. The last argument could
+    # just as well have been zero for blocking mode. Then we could have
+    # left out the sleep call in the bottom of the loop
+    inp = alsaaudio.PCM(alsaaudio.PCM_CAPTURE, alsaaudio.PCM_NONBLOCK, card)
+
+    # Set attributes: Mono, 44100 Hz, 16 bit little endian samples
+    inp.setchannels(1)
+    inp.setrate(44100)
+    inp.setformat(alsaaudio.PCM_FORMAT_S16_LE)
+
+    # The period size controls the internal number of frames per period.
+    # The significance of this parameter is documented in the ALSA api.
+    # For our purposes, it is suficcient to know that reads from the device
+    # will return this many frames. Each frame being 2 bytes long.
+    # This means that the reads below will return either 320 bytes of data
+    # or 0 bytes of data. The latter is possible because we are in nonblocking
+    # mode.
+    inp.setperiodsize(160)
+    
+    loops = 1000000
+    while loops > 0:
+        loops -= 1
+        # Read data from device
+        l, data = inp.read()
+      
+        if l:
+            f.write(data)
+            time.sleep(.001)