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