Mercurial > hg > libxtract
changeset 11:81eb5810a301
Added spectral centroid
| author | Jamie Bullock <jamie@postlude.co.uk> |
|---|---|
| date | Sun, 08 Oct 2006 15:31:40 +0000 |
| parents | 998623a98706 |
| children | 1aec087ddfca |
| files | examples/puredata/xtract~.c src/libxtract.c src/scalar.c xtract/libxtract.h xtract/xtract_scalar.h |
| diffstat | 5 files changed, 32 insertions(+), 1 deletions(-) [+] |
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--- a/examples/puredata/xtract~.c Sun Oct 08 15:05:02 2006 +0000 +++ b/examples/puredata/xtract~.c Sun Oct 08 15:31:40 2006 +0000 @@ -101,6 +101,7 @@ else if(tmp == gensym("average_deviation")) x->feature = AVERAGE_DEVIATION; else if(tmp == gensym("skewness")) x->feature = SKEWNESS; else if(tmp == gensym("kurtosis")) x->feature = KURTOSIS; + else if(tmp == gensym("centroid")) x->feature = CENTROID; else if(tmp == gensym("irregularity_k")) x->feature = IRREGULARITY_K; else if(tmp == gensym("irregularity_j")) x->feature = IRREGULARITY_J; else if(tmp == gensym("tristimulus_1")) x->feature = TRISTIMULUS_1;
--- a/src/libxtract.c Sun Oct 08 15:05:02 2006 +0000 +++ b/src/libxtract.c Sun Oct 08 15:31:40 2006 +0000 @@ -29,6 +29,7 @@ xtract_average_deviation, xtract_skewness, xtract_kurtosis, + xtract_centroid, xtract_irregularity_k, xtract_irregularity_j, xtract_tristimulus_1,
--- a/src/scalar.c Sun Oct 08 15:05:02 2006 +0000 +++ b/src/scalar.c Sun Oct 08 15:31:40 2006 +0000 @@ -84,6 +84,25 @@ } + +int xtract_centroid(float *data, int N, void *argv, float *result){ + + int n = N; + + float *freqs, *amps, FA, A; + + freqs = data; + amps = data + (N >> 1); + + while(n--){ + FA += freqs[n] * amps[n]; + A += amps[n]; + } + + *result = FA / A; + +} + int xtract_irregularity_k(float *data, int N, void *argv, float *result){ int n,
--- a/xtract/libxtract.h Sun Oct 08 15:05:02 2006 +0000 +++ b/xtract/libxtract.h Sun Oct 08 15:31:40 2006 +0000 @@ -38,7 +38,7 @@ #include "xtract_types.h" #include "xtract_macros.h" -#define XTRACT_FEATURES 42 +#define XTRACT_FEATURES 43 #define LOG_LIMIT 10e-10 #define VERY_BIG_NUMBER 2e10 #define SR_LIMIT 192000 @@ -52,6 +52,7 @@ AVERAGE_DEVIATION, SKEWNESS, KURTOSIS, + CENTROID, IRREGULARITY_K, IRREGULARITY_J, TRISTIMULUS_1,
--- a/xtract/xtract_scalar.h Sun Oct 08 15:05:02 2006 +0000 +++ b/xtract/xtract_scalar.h Sun Oct 08 15:31:40 2006 +0000 @@ -82,6 +82,15 @@ */ int xtract_kurtosis(float *data, int N, void *argv, float *result); +/** \brief Extract the kurtosis of an input vector + * + * \param *data: a pointer to the first element in an array of floats represeting a frequency spectrum of size N/2 and a magnitude peak spectrum of size N/2 (This is the output format of xtract_peaks) + * \param N: the number of elements to be considered + * \param *argv: a pointer to NULL + * \param *result: the centroid of the values pointed to by *data + */ +int xtract_centroid(float *data, int N, void *argv, float *result); + /** \brief Calculate the Irregularity of an input vector using a method described by Krimphoff (1994) * * \param *data: a pointer to the first element in an array of floats representing the magnitude spectrum of an audio vector