diff xtract/libxtract.h @ 1:b8f2448f7207

Initial import

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/xtract/libxtract.h	Mon Oct 02 14:18:15 2006 +0000
@@ -0,0 +1,182 @@
+/* libxtract feature extraction library
+ *  
+ * Copyright (C) 2006 Jamie Bullock
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
+ * USA.
+ */
+
+#ifndef XTRACT_H
+#define XTRACT_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** 
+ * \file libxtract.h: main header file and API definition 
+ */
+
+#define VERSION "0.1"
+
+    
+#include "xtract_scalar.h"
+#include "xtract_vector.h"
+#include "xtract_delta.h"
+#include "xtract_types.h"
+#include "xtract_macros.h"
+
+#define XTRACT_FEATURES 40
+#define LOG_LIMIT 10e-10
+#define SR_LIMIT 192000
+#define BARK_BANDS 26
+
+/** \brief Enumeration of features, elements are used as indixes to an array of pointers to feature extracton functions */
+
+enum features_ {
+    MEAN,
+    VARIANCE,
+    STANDARD_DEVIATION,
+    AVERAGE_DEVIATION,
+    SKEWNESS,
+    KURTOSIS,
+    IRREGULARITY_K,
+    IRREGULARITY_J,
+    TRISTIMULUS_1,
+    TRISTIMULUS_2,
+    TRISTIMULUS_3,
+    SMOOTHNESS,
+    SPREAD,
+    ZCR,
+    ROLLOFF,
+    LOUDNESS,
+    FLATNESS,
+    TONALITY,
+    CREST,
+    NOISINESS,
+    RMS_AMPLITUDE,
+    INHARMONICITY,
+    POWER,
+    ODD_EVEN_RATIO,
+    SHARPNESS,
+    SLOPE,
+    F0,
+    HPS,
+    MAGNITUDE_SPECTRUM,
+    AUTOCORRELATION,
+    AUTOCORRELATION_FFT,
+    AMDF,
+    ASDF,
+    MFCC,
+    DCT,
+    BARK_COEFFICIENTS,
+    PEAKS,
+    FLUX,
+    ATTACK_TIME,
+    DECAY_TIME,
+    DELTA_FEATURE
+};
+
+/** \brief Enumeration of feature types */
+
+enum feature_types_ {
+    SCALAR,
+    VECTOR,
+    DELTA
+};
+
+/** \brief Enumeration of mfcc types */
+
+enum mfcc_types_ {
+    EQUAL_GAIN,
+    EQUAL_AREA
+};
+
+/** \brief Enumeration of return codes */
+
+enum return_codes_ {
+    SUCCESS,
+    MALLOC_FAILED,
+    BAD_ARGV,
+    BAD_VECTOR_SIZE
+};
+
+/**
+ *                                                                          
+ * \brief Perform feature extraction
+ *
+ * \param
+ *                                                                           
+ * In general functions in this library conform to the following prototpe:  
+ *                                                                          
+ * int xtract_featurename(float *data, int N, void *argv, float *result)    
+ *                                                                          
+ *                                                                          
+ *      float *data: a pointer to an array element                          
+ *                                                                          
+ *      int N: the number of elements to be processed by the function          
+ *                                                                          
+ *      void *argv: an abitrary number of additional arguments 
+ *                                                                          
+ *      float *result: a pointer to the result                              
+ *                                                                          
+ *                                                                          
+ * Each function will iterate over N array elements, the first of which is  
+ * pointed to by *data. It is therefore up to the caller to ensure that an  
+ * approriate range of data is provided. For example, if the function expects
+ * an array containing an harmonic spectrum, then they array pointed to by 
+ * *data must contain the amplitudes of harmonic frequencies in adjacent 
+ * elemets
+ *                                                                          
+ * For scalar and delta features, *result will point to a single value.     
+ *                                                                          
+ * For vector features it will point to the first element in an array.      
+ *                                                                          
+ * Memory for this array must be allocated and freed by the calling         
+ * function.                                                                
+ *  
+ *  All functions return an integer error code as descibed in the enumeration
+ *  return_codes_
+ *                                                                          
+ * */
+
+
+int(*xtract[XTRACT_FEATURES])(float *, int, void *, float *);
+
+/* Data structures */
+
+typedef struct xtract_mel_filter_ {
+    int n_filters;
+    float **filters;
+} xtract_mel_filter;
+
+
+/* Initialisation functions */
+/* xtract_init_mfcc */
+/* It is up to the caller to pass in a pointer to memory allocated for freq_bands arrays of length N. This function populates these arrays with magnitude coefficients representing the mel filterbank on a linear scale */
+int xtract_init_mfcc(int N, float nyquist, int style, float freq_max, float freq_min, int freq_bands, float **fft_tables);
+
+/* xtract_init_bark */
+/* A pointer to an array of BARK_BANDS ints most be passed in, and is populated with BARK_BANDS fft bin numbers representing the limits of each band */
+int xtract_init_bark(int N, float nyquist, int *band_limits);
+
+
+/* Free functions */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif