double blok::deviation(){
double total = std::accumulate(content.begin(), content.end(), 0);
double mean = total / content.size();
vector<unsigned int> zero_mean( content );
transform( zero_mean.begin(), zero_mean.end(), zero_mean.begin(),bind2nd( minus<double>(), mean ) );
double deviation = inner_product( zero_mean.begin(),zero_mean.end(), zero_mean.begin(), 0.0 );
deviation = sqrt( deviation / ( content.size() - 1 ) );
return deviation;
}
/*
* Get the MFCC feature for a raw voice data. You can get the sample from the
* wav filer header.
*
* @param data the raw data the wav file
* @param len the length of the wav raw data
* @param sample_rate sample frequency in Hz (8000 or 16000 or 22050 or 44000)
* @param mfcc mfcc (39 dimension, in the program)
* @param frame_time the time(in ms) you take it as a frame
* @param step_time the time(in ms) between two neighbor frame
*
*/
int array_to_mfcc(const double* data, const int len, int sample_rate,
double*** mfcc_data, double frame_time, double step_time) {
int i, j;
/* (frame size / sameple rate) * 1000 = frame time */
// int frame_size = sample_rate * frame_time / 1000;
// int move_size = sample_rate * step_time / 1000;
int frame_size = 240;
int move_size = 80;
int n = (len - frame_size) / move_size + 1; /* total number of frames */
int tmp = log(frame_size * 1.0) / log(2.0);
double** mfcc; /* temp data for storing mfcc */
double* tmp_data; /* temp data for storing each frame */
double* lo_chan;
double* lo_wt;
double* cep_win; /* weighted window for MFCC */
double* fbank; /* triangular bandpass filter */
int fft_n; /* */
if ((int)pow(2.0, tmp * 1.0) + 0.5 >= frame_size) {
fft_n = (int)pow(2.0, tmp) + 0.5;
} else {
fft_n = (int)pow(2.0, tmp + 1) + 0.5;
}
mfcc = (double**) calloc(n, sizeof(double*));
for (i = 0; i < n; ++i) {
mfcc[i] = (double*) calloc(MFCC_DIMENSION, sizeof(double));
}
tmp_data = (double*) calloc(fft_n, sizeof(double));
lo_chan = (double*) calloc(fft_n, sizeof(double));
lo_wt = (double*) calloc(fft_n, sizeof(double));
cep_win = (double*) calloc(12, sizeof(double));
fbank = (double*) calloc(27, sizeof(double));
gen_cep_win(cep_win, 22, 12);
for (i = 0; i < n; ++i) {
for (j = 0; j < frame_size; ++j) {
tmp_data[j] = data[i * move_size + j];
}
for (j = frame_size; j < fft_n; ++j) {
tmp_data[j] = 0.0;
}
mfcc[i][12] = cpt_energy(tmp_data, frame_size);
pre_emphasise(tmp_data, frame_size);
hamming(tmp_data, frame_size);
realft(tmp_data, fft_n);
init_mel(lo_chan, lo_wt, sample_rate, fft_n);
wave_to_fbank(tmp_data, fbank, lo_chan, lo_wt, fft_n);
fbank_to_mfcc(mfcc[i], fbank, 12);
weight_cep(mfcc[i], cep_win, 12);
}
get_delta_cep(mfcc, n, 13, 2);
zero_mean(mfcc, n, 12);
*mfcc_data = mfcc; /* */
free(tmp_data);
free(lo_chan);
free(lo_wt);
free(cep_win);
free(fbank);
return n;
}