# -*- coding: utf-8 -*-
"""
Inicialização para o 1º trabalho de laboratório de Sinais e Sistemas

Created on Wed Feb 26 18:38:20 2014

@author: lba
"""

def sistema1(x):
	sx = size(x)
	delay = floor(.25 * samplingrate)		# Delay of 0.5s, measured in samples
	y = zeros(sx+delay)					# Reserve enough space for the delayed signal
	y[0:sx] = x
	y[delay : sx+delay] += x / 2
	y = append(zeros(delay), y)
	return y

def u(t):
	return float_(t>=0)          # float_ is the numpy standard function for conversion to float (equivalent to float64)

def tplot(x):
	duration = (size(x) - 1) / samplingrate
	t = timevar(duration)						# Time variable local to this function
	plot(t,x)

def timevar(duration):
	tlim = duration / 2
	t = arange(-tlim * samplingrate, tlim * samplingrate + .1, 1) / samplingrate    # This gives exact values for integer values of t
	return t
	
def play(x):
	x = clip(x, -1, 1)									# If |x|>1 this would give a strong distortion
	wavwrite('play.wav', samplingrate, (32767*x).astype(int16))
	PlaySound('play.wav',0)								# Set the second argument to 1 to returm immediately to the calling program
	removefile('play.wav')

def seqsin(*arg):
	"""Generate a sequence of sinusoids with specified frequencies and durations.
	"""
	if mod(len(arg),2) != 0:
		print('seqsin: Number of arguments must be even')
		return
	t1 = .001 * samplingrate							# Duration, in samples, of the initial taper
	t2 = .01 * samplingrate							# Duration, in samples, of the final taper
	y = zeros(0)									# Initialize output array
	pos = 0										# Initialize position in which we are in the output array
	for nseg in range(int(len(arg) / 2)):
		freq = arg[2*nseg]
		duration = arg[2*nseg+1] * samplingrate			# Duration of this segment, in samples
		i = arange(t1)
		y = append(y, .5 * (1 + cos(pi / t1 * (i - t1))) * sin(2 * pi * freq / samplingrate * i))
		i = arange(t1, duration-t2)
		y = append(y, sin(2 * pi * freq / samplingrate * i))
		i = arange(duration-t2, duration)
		y = append(y, .5 * (1 + cos(pi / t2 * (i - duration + t2 + 1))) * sin(2 * pi * freq / samplingrate * i))
		pos += duration
	return y
		
	
# import pdb				

from numpy import *
from matplotlib.pyplot import plot
from os import remove as removefile
from scipy.io.wavfile import write as wavwrite
from scipy.io.wavfile import read as wavread
#from winsound import PlaySound
from soundapi import *

from sistema2 import *

samplingrate = 16000

x = wavread('fala.wav')
fala = array(x[1]) / 32767		# x[0] contains the sampling rate of the wav file, which is 16000 for this file
del x

print("\n\nSinais e Sistemas - 1º trabalho de laboratório: inicialização concluída.\n")