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import audio
RATE = 8192
# Initialize the audio stuff
audio.setrate(3)
audio.setoutgain(100) # for speaker
play = audio.write
def samp(n):
savegain = audio.getoutgain()
try:
audio.setoutgain(0)
x = raw_input('Hit Enter to sample ' + `n` + ' seconds: ')
return audio.read(n*RATE)
finally:
audio.setoutgain(savegain)
def echo(s, delay, gain):
return s[:delay] + audio.add(s[delay:], audio.amplify(s, gain, gain))
def save(s, file):
f = open(file, 'w')
f.write(s)
def load(file):
return loadfp(open(file, 'r'))
def loadfp(fp):
s = ''
while 1:
buf = fp.read(16*1024)
if not buf: break
s = s + buf
return s
def unbias(s):
if not s: return s
a = audio.chr2num(s)
sum = 0
for i in a: sum = sum + i
bias = (sum + len(a)/2) / len(a)
print 'Bias value:', bias
if bias:
for i in range(len(a)):
a[i] = a[i] - bias
s = audio.num2chr(a)
return s
# Stretch by a/b.
# Think of this as converting the sampling rate from a samples/sec
# to b samples/sec. Or, if the input is a bytes long, the output
# will be b bytes long.
#
def stretch(s, a, b):
y = audio.chr2num(s)
m = len(y)
out = []
n = m * b / a
# i, j will walk through y and out (step 1)
# ib, ja are i*b, j*a and are kept as close together as possible
i, ib = 0, 0
j, ja = 0, 0
for j in range(n):
ja = ja+a
while ib < ja:
i = i+1
ib = ib+b
if i >= m:
break
if ib == ja:
out.append(y[i])
else:
out.append((y[i]*(ja-(ib-b)) + y[i-1]*(ib-ja)) / b)
return audio.num2chr(out)
def sinus(freq): # return a 1-second sine wave
from math import sin, pi
factor = 2.0*pi*float(freq)/float(RATE)
list = range(RATE)
for i in list:
list[i] = int(sin(float(i) * factor) * 127.0)
return audio.num2chr(list)
def softclip(s):
if '\177' not in s and '\200' not in s:
return s
num = audio.chr2num(s)
extremes = (-128, 127)
for i in range(1, len(num)-1):
if num[i] in extremes:
num[i] = (num[i-1] + num[i+1]) / 2
return audio.num2chr(num)
def demo():
gday = load('gday')[1000:6000]
save(gday, 'gday0')
gg = [gday]
for i in range(1, 10):
for g in gg: play(g)
g = stretch(gday, 10, 10-i)
save(g, 'gday' + `i`)
gg.append(g)
while 1:
for g in gg: play(g)
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