In [1]:

    

import math
import pyaudio


    

In [35]:

    

PyAudio = pyaudio.PyAudio

BITRATE = 24000 #number of frames per second/frameset.      
FREQUENCY = 261.6 #Hz, waves per second, 261.63=C4-note.
LENGTH = 1. #seconds to play sound

NUMBEROFFRAMES = int(BITRATE * LENGTH)
RESTFRAMES = NUMBEROFFRAMES % BITRATE
WAVEDATA = ''    

for x in xrange(NUMBEROFFRAMES):
 WAVEDATA = WAVEDATA+chr(int(math.sin(x/((BITRATE/FREQUENCY)/math.pi))*127+128))    

#fill remainder of frameset with silence
for x in xrange(RESTFRAMES): 
 WAVEDATA = WAVEDATA+chr(128)

p = PyAudio()
stream = p.open(format = p.get_format_from_width(1), 
                channels = 1, 
                rate = BITRATE, 
                output = True)
stream.write(WAVEDATA)
stream.stop_stream()
stream.close()
p.terminate()


    

In [38]:

    

import numpy as np
from matplotlib import pyplot as plt
%matplotlib inline


    

In [1]:

    

from struct import pack
from math import sin, pi


    

In [33]:

    

# create a sound file in AU format playing a sine wave
# of a given frequency, duration and volume
def au_file(name='test.au', freq=440, dur=1000, vol=0.5, lead=0, tail=0):
    """
    creates an AU format sine wave audio file
    of frequency freq (Hz)
    of duration dur (milliseconds)
    and volume vol (max is 1.0)
    """
    fout = open(name, 'wb')
    
    total = lead + dur + tail
    
    values = []
    
    # header needs size, encoding=2, sampling_rate=8000, channel=1
    fout.write(pack('>4s5L', '.snd'.encode("utf8"), 24, 8*total, 2, 8000, 1))
    factor = 2 * pi * freq/8000
    
    # write lead
    for seg in range(8 * lead):
        val = pack('b', 0)
        fout.write(val)
        values.append(0)
        
    # write data
    for seg in range(8 * dur):
        # sine wave calculations
        sin_seg = sin(seg * factor)
        v = vol * 127 * sin_seg
        val = pack('b', int(v))
        fout.write(val)
        values.append(v)
        
    # write tail
    for seg in range(8 * tail):
        val = pack('b', 0)
        fout.write(val)
        values.append(0)
        
    fout.close()
    print("File %s written" % name)
    
    return values


    

In [37]:

    

sound = au_file(name='sound440_2.au', freq=150, dur=500, vol=1.0, lead=500, tail=500)


    

    




File sound440_2.au written

In [39]:

    

plt.figure(figsize=(20,4))
plt.plot(sound)
plt.show()


    

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