gistfile1.txt

#!/bin/python2

# Name: Kyle Holzinger

import readWave as rd
from math import atan, floor
from matplotlib import pyplot as plt

def pitch(name, start):
	# Skips first 2 seconds of file
	indata, params = rd.readwav(name)
	time = 0.05

	len_indata = len(indata)
	samples = int(time * params[2])
	W = 2205
	difference = []
	S = 88200 + start

	indata = indata[S:]

	# Difference function
	for lag in xrange(0,samples):
	    total = 0
	    for i in xrange(1, W):
	        total += (indata[i] - indata[i+lag]) ** 2
	    difference.append(total)

	dtp = [1]

	for lag in range(1, samples):
		denom = float(sum([difference[j] for j in xrange(1, lag+1)])) / lag
		dtp.append(difference[lag]/denom)

	dtp = [-el for el in dtp]

	# Valley Picking Algorithm
	for i in range(1,len(dtp)-1):
		if dtp[i] < dtp[i-1] and dtp[i] < dtp[i+1]:
			first_min = dtp.index(dtp[i])
			# print("First min at: %d"%first_min)
			break

	for i in range(first_min, len(dtp)-1):
		if dtp[i] > dtp[i-1] and dtp[i] > dtp[i+1]:
			max_x = dtp.index(dtp[i]) + 0.0
			# print("First max at: %d"%max_x)
			break

	return 1/(max_x / params[2])