jamie@1: /* libxtract feature extraction library
jamie@1:  *  
jamie@1:  * Copyright (C) 2006 Jamie Bullock
jamie@1:  *
jamie@1:  * This program is free software; you can redistribute it and/or modify
jamie@1:  * it under the terms of the GNU General Public License as published by
jamie@1:  * the Free Software Foundation; either version 2 of the License, or
jamie@1:  * (at your option) any later version.
jamie@1:  *
jamie@1:  * This program is distributed in the hope that it will be useful,
jamie@1:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
jamie@1:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
jamie@1:  * GNU General Public License for more details.
jamie@1:  *
jamie@1:  * You should have received a copy of the GNU General Public License
jamie@1:  * along with this program; if not, write to the Free Software
jamie@1:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
jamie@1:  * USA.
jamie@1:  */
jamie@1: 
jamie@1: /* xtract_delta.c: defines functions that extract a feature as a single value from more than one input vector */
jamie@1: 
jamie@106: #include <math.h>
jamie@106: 
jamie@38: #include "xtract/libxtract.h"
jamie@1: 
jamie@43: int xtract_flux(const float *data, const int N, const void *argv , float *result){
jamie@1: 
jamie@117:     /* FIX: don't be lazy -- take the lnorm of the difference vector! */
jamie@106:     return xtract_lnorm(data, N, argv, result);
jamie@105: 
jamie@106: }
jamie@106: 
jamie@106: int xtract_lnorm(const float *data, const int N, const void *argv , float *result){
jamie@106: 
jamie@107:     int n,
jamie@106:         type;
jamie@106: 
jamie@111:     float order;
jamie@106: 
jamie@106:     order = *(float *)argv;
jamie@111:     type = *((float *)argv+1);
jamie@106: 
jamie@108:     order = order > 0 ? order : 2.f;
jamie@106: 
jamie@111:     *result = 0.f;
jamie@111: 
jamie@106:     switch(type){
jamie@106: 
jamie@106:         case XTRACT_POSITIVE_SLOPE:
jamie@106:             for(n = 0; n < N; n++){
jamie@106:                 if(data[n] > 0)
jamie@111:                     *result += powf(data[n], order);
jamie@106:             }
jamie@106:             break;
jamie@106:         default:
jamie@106:             for(n = 0; n < N; n++)
jamie@106:                 *result += powf(data[n], order);
jamie@106:             break;
jamie@106: 
jamie@106:     }
jamie@106: 
jamie@106:     *result = powf(*result, 1.f / order);
jamie@106: 
jamie@106:     return XTRACT_SUCCESS;
jamie@1: 
jamie@1: }
jamie@1: 
jamie@43: int xtract_attack_time(const float *data, const int N, const void *argv , float *result){
jamie@1: 
jamie@56:     return XTRACT_FEATURE_NOT_IMPLEMENTED;
jamie@1: 
jamie@1: }
jamie@1: 
jamie@43: int xtract_decay_time(const float *data, const int N, const void *argv, float *result){
jamie@1: 
jamie@56:     return XTRACT_FEATURE_NOT_IMPLEMENTED;
jamie@1: 
jamie@1: }
jamie@1: 
jamie@106: int xtract_difference_vector(const float *data, const int N, const void *argv, float *result){
jamie@1: 
jamie@107:     const float *frame1,
jamie@106:           *frame2;
jamie@106: 
jamie@106:     int n;
jamie@106: 
jamie@106:     n = N >> 1;
jamie@106: 
jamie@106:     frame1 = data;
jamie@106:     frame2 = data + n;
jamie@106: 
jamie@106:     while(n--)
jamie@106:         result[n] = frame1[n] - frame2[n];
jamie@106: 
jamie@106:     return XTRACT_SUCCESS;
jamie@1: 
jamie@1: }