[python] 讀取訊號

下面範例以聲音訊號為例，示範如何讀取與寫入二元制(binary)檔案。程式碼說明請參考 http://hcliao.twbbs.org/signal-processing-using-python/signal-processing-using-python/read-signal

import scipy.io.wavfile as wav

import numpy as np

import struct

from pylab import *

close('all')

# read .wav file using scipy.io.wavfile module

iWav = wav.read('../voxforgeivr-20070410-062052-1176186024.14/wav/vf3-06.wav')

figure(1)

subplot(2,1,1)

plot(iWav[1])

# write data in binary format to a file

fpBin = open('wav.pcm', 'wb')

for num in iWav[1]:

    data = struct.pack('i', num)

    fpBin.write(data)

fpBin.close()

# read binary data from the file

iResult = array([])

fpBin = open('wav.pcm', 'rb')

iSize = struct.calcsize('i')

while 1:

    data = fpBin.read(iSize)

    if data == '':

        break

    num = struct.unpack('i', data)

    iResult = np.append(iResult, num)

fpBin.close()

subplot(2,1,2)

plot(iResult)

show()