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_scalar.h: declares functions that extract a feature as a vector from an input vector */
jamie@1: 
jamie@1: #ifndef XTRACT_VECTOR
jamie@1: #define XTRACT_VECTOR
jamie@1: 
jamie@1: #ifdef __cplusplus
jamie@1: extern "C" {
jamie@1: #endif
jamie@20: 	
jamie@20: /**
jamie@20:   * \defgroup vector extraction functions
jamie@20:   *
jamie@20:   * Defines vectorr extraction functions, and their parameters.
jamie@20:   * @{
jamie@20:   */
jamie@1: 
jamie@2: /** \brief Extract normalized (0-1) frequency domain magnitude spectrum from time domain signal 
jamie@2:  * 
jamie@2:  * \param *data: a pointer to the first element in an array of floats representing an audio vector
jamie@2:  * \param N: the number of array elements to be considered
jamie@2:  * \param *argv: a pointer to NULL 
jamie@2:  * \param *result: the magnitude spectrum of N values from the array pointed to by *data 
jamie@2:  */
jamie@1: int xtract_magnitude_spectrum(float *data, int N, void *argv, float *result);
jamie@1: 
jamie@1: 
jamie@2: /** \brief Extract autocorrelation from time domain signal using time-domain autocorrelation technique 
jamie@2:  * 
jamie@2:  * \param *data: a pointer to the first element in an array of floats representing an audio vector
jamie@2:  * \param N: the number of array elements to be considered
jamie@2:  * \param *argv: a pointer to NULL 
jamie@2:  * \param *result: the autocorrelation of N values from the array pointed to by *data 
jamie@2:  */
jamie@1: int xtract_autocorrelation(float *data, int N, void *argv, float *result);
jamie@1: 
jamie@2: /** \brief Extract autocorrelation from time domain signal using FFT based method
jamie@2:  * 
jamie@2:  * \param *data: a pointer to the first element in an array of floats representing an audio vector
jamie@2:  * \param N: the number of array elements to be considered
jamie@2:  * \param *argv: a pointer to NULL 
jamie@2:  * \param *result: the autocorrelation of N values from the array pointed to by *data 
jamie@2:  */
jamie@1: int xtract_autocorrelation_fft(float *data, int N, void *argv, float *result);
jamie@1: 
jamie@2: /** \brief Extract Average Magnitude Difference Function from time domain signal 
jamie@2:  * 
jamie@2:  * \param *data: a pointer to the first element in an array of floats
jamie@2:  * \param N: the number of array elements to be considered
jamie@2:  * \param *argv: a pointer to NULL 
jamie@2:  * \param *result: the AMDF of N values from the array pointed to by *data 
jamie@2:  */
jamie@1: int xtract_amdf(float *data, int N, void *argv, float *result);
jamie@1:     
jamie@2: /** \brief Extract Average Squared Difference Function from time domain signal 
jamie@2:  * 
jamie@2:  * \param *data: a pointer to the first element in an array of floats representing an audio vector
jamie@2:  * \param N: the number of array elements to be considered
jamie@2:  * \param *argv: a pointer to NULL 
jamie@2:  * \param *result: the ASDF of N values from the array pointed to by *data 
jamie@2:  */
jamie@1: int xtract_asdf(float *data, int N, void *argv, float *result);
jamie@1:     
jamie@2: /** \brief Extract Mel Frequency Cepstral Coefficients based on a method described by Rabiner
jamie@2:  * 
jamie@2:  * \param *data: a pointer to the first element in an array of floats
jamie@2:  * \param N: the number of array elements to be considered
jamie@2:  * \param *argv: a pointer to a data structure of type xtract_mel_filter, containing n_filters coefficient tables to make up a mel-spaced filterbank
jamie@2:  * \param *result: a pointer to an array containing the resultant MFCC
jamie@2:  * 
jamie@2:  * The data structure pointed to by *argv must be obtained by first calling xtract_init_mfcc
jamie@2:  */
jamie@1: int xtract_mfcc(float *data, int N, void *argv, float *result);
jamie@1: 
jamie@2: /** \brief Extract Bark band coefficients based on a method   
jamie@2:  * \param *data: a pointer to the first element in an array of floats representing the magnitude spectrum of an audio vector
jamie@2:  * \param N: the number of array elements to be considered
jamie@2:  * \param *argv: a pointer to an array of ints representing the limits of each bark band
jamie@2:  * \param *result: a pointer to an array containing resultant bark coefficients
jamie@2:  *
jamie@2:  * The limits array pointed to by *argv must be obtained by first calling xtract_init_bark
jamie@2:  * 
jamie@2:  */
jamie@1: int xtract_bark_coefficients(float *data, int N, void *argv, float *result);
jamie@1: 
jamie@2: /** \brief Extract the Discrete Cosine transform of a time domain signal
jamie@2:  * \param *data: a pointer to the first element in an array of floats representing an audio vector
jamie@2:  * \param N: the number of array elements to be considered
jamie@2:  * \param *argv: a pointer to NULL 
jamie@2:  * \param *result: a pointer to an array containing resultant dct coefficients
jamie@2:  */
jamie@1: int xtract_dct(float *data, int N, void *argv, float *result);
jamie@1: 
jamie@2: /** \brief Extract the frequency and amplitude of spectral peaks from a of a magnitude spectrum
jamie@2:  * \param *data: a pointer to the first element in an array of floats representing the magnitude spectrum of an audio vector
jamie@2:  * \param N: the number of array elements to be considered
jamie@2:  * \param *argv: a pointer to an array containing peak threshold as percentage below max peak, and sample rate 
jamie@2:  * \param *result: a pointer to an array of size N, containing N/2 freqs and N/2 amplitudes, amplitudes are on a decibel scale with dbFS = 0 
jamie@2:  */
jamie@1: int xtract_peaks(float *data, int N, void *argv, float *result);
jamie@20: 
jamie@20: /** @} */
jamie@20: 
jamie@1: #ifdef __cplusplus
jamie@1: }
jamie@1: #endif
jamie@1: 
jamie@1: #endif