hamel@448: #!/usr/bin/env python
hamel@448: #
hamel@448: #  audio_example.py
hamel@448: #  
hamel@448: #
hamel@448: #  Created by Philippe Hamel (hamel.phil@gmail.com) on 11-01-05.
hamel@448: #
hamel@448: # methods to read and write aimc data files
hamel@448: 
hamel@448: from struct import *
hamel@448: import numpy as N
hamel@448: 
hamel@448: #int_size = calcsize('i')
hamel@448: #float_size =  calcsize('d')
hamel@448: 
hamel@448: def readbin(type,file) :
hamel@448:     """
hamel@448:     used to read binary data from a file
hamel@448:     """
hamel@448:     return unpack(type,file.read(calcsize(type)))
hamel@448: 
hamel@448: def read_aimc_data(filename):
hamel@448:     file = open(filename,'rb')
hamel@448:         
hamel@448:     nFrames = readbin('i',file)[0]
hamel@448:     period = readbin( 'f', file)[0] # Frame period in ms
hamel@448:     nChannels = readbin( 'i', file)[0] # vertical axis of an AI
hamel@448:     nSamples = readbin( 'i', file)[0] # horizontal axis of an AI
hamel@448:     sample_rate = readbin('f', file)[0] # sample rate of each channel in Hz
hamel@448:     
hamel@448:     print 'nFrames, period, nChannels, nSamples, sample_rate'
hamel@448:     print nFrames, period, nChannels, nSamples, sample_rate
hamel@448:     
hamel@448:     nData = nFrames * nChannels * nSamples
hamel@448:     print nData
hamel@448:     vec_data = readbin('%if'%nData,file)
hamel@448:     
hamel@448:     file.close()
hamel@448:     data = N.reshape(vec_data,(nFrames, nChannels, nSamples))
hamel@448:     return data, nFrames, period, nChannels, nSamples, sample_rate
hamel@448: 
hamel@450: def write_aimc_data(filename, data, sample_rate, period = 0.0):
hamel@450: 
hamel@450:     nFrames, nChannels, nSamples = data.shape
hamel@450:     
hamel@450:     file = open(filename,'wb')
hamel@450:     
hamel@450:     file.write(pack('i',nFrames))
hamel@450:     file.write(pack('f',period)) #Not correctly implemented yet
hamel@450:     file.write(pack('i',nChannels))
hamel@450:     file.write(pack('i',nSamples))
hamel@450:     file.write(pack('f',sample_rate))
hamel@450:     
hamel@450:     vec_data = data.flatten()
hamel@450:     for elem in vec_data:
hamel@450:         file.write(pack('f',elem))
hamel@450: 
hamel@451:     file.close()
hamel@450: