diff options
Diffstat (limited to 'xtract/libxtract.h')
| -rw-r--r-- | xtract/libxtract.h | 55 |
1 files changed, 20 insertions, 35 deletions
diff --git a/xtract/libxtract.h b/xtract/libxtract.h index 960aa66..0e4f254 100644 --- a/xtract/libxtract.h +++ b/xtract/libxtract.h @@ -44,7 +44,6 @@ extern "C" { #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, @@ -90,7 +89,6 @@ enum features_ { }; /** \brief Enumeration of feature types */ - enum feature_types_ { SCALAR, VECTOR, @@ -98,14 +96,12 @@ enum feature_types_ { }; /** \brief Enumeration of mfcc types */ - enum mfcc_types_ { EQUAL_GAIN, EQUAL_AREA }; /** \brief Enumeration of return codes */ - enum return_codes_ { SUCCESS, MALLOC_FAILED, @@ -115,30 +111,18 @@ enum return_codes_ { /** * - * \brief Perform feature extraction - * - * \param - * - * In general functions in this library conform to the following prototpe: + * \brief An array of pointers to functions that perform the extraction * - * int xtract_featurename(float *data, int N, void *argv, float *result) + * \param *data: a pointer to the start of the input data (usually the first element in an array) * + * \param N: the number of elements to be processed * - * 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 + * \param *argv: an abitrary number of additional arguments, used to pass additional parameters to the function being called * + * \param *result: a pointer to the first element in 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 + * pointed to by *data. It is up to the calling function to ensure that the array is in the format expected by the function being called. * * For scalar and delta features, *result will point to a single value. * @@ -149,27 +133,28 @@ enum return_codes_ { * * All functions return an integer error code as descibed in the enumeration * return_codes_ - * - * */ - - -int(*xtract[XTRACT_FEATURES])(float *, int, void *, float *); - -/* Data structures */ + * + * example:<br> + * xtract[PEAKS](amplitude_spectrum, 512, threshold, peaks) + */ +int(*xtract[XTRACT_FEATURES])(float *data, int N, void *argv, float *result); +/** \brief A structure to store a set of n_filters Mel filters */ 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 */ +/** \brief A function to initialise a mel filter bank + * + * 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 */ +/** \brief A function to initialise bark filter bounds + * + * 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); |