jamie@141: /*
jamie@141:  * Copyright (C) 2012 Jamie Bullock
jamie@140:  *
jamie@141:  * Permission is hereby granted, free of charge, to any person obtaining a copy
jamie@141:  * of this software and associated documentation files (the "Software"), to
jamie@141:  * deal in the Software without restriction, including without limitation the
jamie@141:  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
jamie@141:  * sell copies of the Software, and to permit persons to whom the Software is
jamie@141:  * furnished to do so, subject to the following conditions:
jamie@107:  *
jamie@141:  * The above copyright notice and this permission notice shall be included in
jamie@141:  * all copies or substantial portions of the Software.
jamie@107:  *
jamie@141:  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
jamie@141:  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
jamie@141:  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
jamie@141:  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
jamie@141:  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
jamie@141:  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
jamie@141:  * IN THE SOFTWARE.
jamie@107:  *
jamie@107:  */
jamie@107: 
jamie@107: /* helper.c: helper functions. */
jamie@107: 
jamie@113: #include <stdio.h>
jamie@113: 
jamie@259: #include "xtract/libxtract.h"
jamie@107: 
jamie@113: #ifdef WORDS_BIGENDIAN
jamie@113: #define INDEX 0
jamie@113: #else
jamie@113: #define INDEX 1
jamie@113: #endif
jamie@113: 
jamie@146: int xtract_windowed(const double *data, const int N, const void *argv, double *result)
jamie@140: {
jamie@107: 
jamie@107:     int n;
jamie@146:     const double *window;
jamie@107: 
jamie@107:     n = N;
jamie@146:     window = (const double *)argv;
jamie@107: 
jamie@107:     while(n--)
jamie@107:         result[n] = data[n] * window[n];
jamie@107: 
jamie@107:     return XTRACT_SUCCESS;
jamie@107: 
jamie@107: }
jamie@107: 
jamie@146: int xtract_features_from_subframes(const double *data, const int N, const int feature, const void *argv, double *result)
jamie@140: {
jamie@107: 
jamie@146:     const double *frame1,
jamie@107:           *frame2;
jamie@146:     double *result1,
jamie@107:           *result2;
jamie@107: 
jamie@113:     int n, rv;
jamie@107: 
jamie@107:     n = N >> 1;
jamie@107: 
jamie@107:     frame1 = data;
jamie@107:     frame2 = data + n;
jamie@107:     result1 = result;
jamie@107:     result2 = result + n;
jamie@107: 
jamie@107:     rv = xtract[feature](frame1, n, argv, result1);
jamie@107: 
jamie@107:     if(rv == XTRACT_SUCCESS)
jamie@107:         rv = xtract[feature](frame2, n, argv, result2);
jamie@107: 
jamie@107:     return rv;
jamie@107: 
jamie@107: }
jamie@113: 
jamie@244: 
jamie@244: /*
jamie@244:  * Implements y[n] = k * x[n] + (1-k) * y[n-1]
jamie@244:  */
jamie@244: int xtract_smoothed(const double *data, const int N, const void *argv, double *result)
jamie@244: {
jamie@244:     double gain = *(double *)argv;
jamie@244:     double oneminusgain = 1.0 - gain;
jamie@244:     int i;
jamie@244:     
jamie@244:     // reverse filtering first
jamie@244:     for (i = N - 2; i >= 0; i--)
jamie@244:     {
jamie@244:         result[i] = gain * data[i] + oneminusgain * data[i+1];
jamie@244:     }
jamie@244:     
jamie@244:     // then forward filtering
jamie@244:     for (i = 1; i < N; i++)
jamie@244:     {
jamie@244:         result[i] = gain * result[i] + oneminusgain * result[i-1];
jamie@244:     }
jamie@244: 
jamie@244:     return XTRACT_SUCCESS;
jamie@244: }
jamie@244: 
jamie@244: 
andrea@211: //inline int xtract_is_denormal(double const d)
andrea@211: int xtract_is_denormal(double const d)
jamie@140: {
jamie@113:     if(sizeof(d) != 2 * sizeof(int))
jamie@113:         fprintf(stderr, "libxtract: Error: xtract_is_denormal() detects inconsistent wordlength for type 'double'\n");
jamie@113: 
jamie@113:     int l = ((int *)&d)[INDEX];
jamie@113:     return (l&0x7ff00000) == 0 && d!=0; //Check for 0 may not be necessary
jamie@113: }
jamie@113: 
andrea@211: //inline bool xtract_is_poweroftwo(unsigned int x)
andrea@211: bool xtract_is_poweroftwo(unsigned int x)
jamie@140: {
jamie@140:     return ((x != 0) && !(x & (x - 1)));
jamie@140: }
jamie@140: