#!/usr/bin/python

# Create a very stupid wav file (absolute silence)

import sys, wave, struct

try:
	duration_in_minutes = int(sys.argv[1])
except:
	print >>sys.stderr, 'usage: %s {duration_in_minutes}' % sys.argv[0]
	sys.exit(1)

# CD quality: two channels (stereo), 16 bit, sampling rate 44100 values per second
number_of_channels = 2
bytes_per_value    = 2
sampling_rate      = 44100

### Write header
w = wave.open('%d_minutes_of_silence.wav' % duration_in_minutes, 'wb')
w.setframerate(sampling_rate)
w.setnchannels(number_of_channels)
w.setsampwidth(bytes_per_value)

### Create one minute of sound.
### You may modify the following line in order to get more beautiful music.
one_second_of_silence = struct.pack('h',0) * sampling_rate * number_of_channels
one_minute_of_silence = one_second_of_silence * 60

### Write sound of one second at a time
for minute in xrange(1,duration_in_minutes+1):
	w.writeframes(one_minute_of_silence)
	if   minute %  5: sys.stdout.write('.')
	elif minute % 10: sys.stdout.write('+')
	else: sys.stdout.write(str(minute))
	sys.stdout.flush()

print '\nDone.'
w.close()