shithub: soundpipe

ref: ffe16b59b7ae8c2e00dffa7bba7c9d7b9238c9f5
dir: /modules/ftbl.c/

#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifndef NO_LIBSNDFILE
#include <sndfile.h>
#endif
#include "soundpipe.h"
#include "kiss_fftr.h"

#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif

#define tpd360 0.0174532925199433

int sp_ftbl_init(sp_data *sp, sp_ftbl *ft, size_t size)
{
    ft->size = size;
    memset(ft->tbl, 0, sizeof(SPFLOAT) * size);
    return SP_OK;
}

int sp_ftbl_create(sp_data *sp, sp_ftbl **ft, size_t size)
{
    sp_ftbl *ftp;
    *ft = malloc(sizeof(sp_ftbl));
    ftp = *ft;
    ftp->tbl = calloc(1, sizeof(SPFLOAT) * (size + 1));
    sp_ftbl_init(sp, ftp, size);
    return SP_OK;
}

int sp_ftbl_destroy(sp_ftbl **ft)
{
    sp_ftbl *ftp = *ft;
    free(ftp->tbl);
    free(*ft);
    return SP_OK;
}

static char * tokenize(char **next, int *size)
{
    char *token;
    char *str;
    char *peak;

    if (*size <= 0) return NULL;
    token = *next;
    str = *next;

    peak = str + 1;

    while ((*size)--) {
        if (*str == ' ') {
            *str = 0;
            if (*peak != ' ') break;
        }
        str = str + 1;
        peak = str + 1;
    }
    *next = peak;
    return token;
}

int sp_gen_vals(sp_data *sp, sp_ftbl *ft, const char *string)
{
    int size;
    char *str;
    char *out;
    char *ptr;
    int j;

    size = strlen(string);
    str = malloc(sizeof(char) * size + 1);
    strcpy(str, string);
    ptr = str;
    j = 0;

    while (size > 0) {
        out = tokenize(&str, &size);
        if (ft->size < j + 1) {
            ft->tbl = realloc(ft->tbl, sizeof(SPFLOAT) * (ft->size + 2));
            /* zero out new tables */
            ft->tbl[ft->size] = 0;
            ft->tbl[ft->size + 1] = 0;
            ft->size++;
        }
        ft->tbl[j] = atof(out);
        j++;
    }
    free(ptr);
    return SP_OK;
}

int sp_gen_sine(sp_data *sp, sp_ftbl *ft)
{
    unsigned long i;
    SPFLOAT step = 2 * M_PI / ft->size;
    for (i = 0; i < ft->size; i++) {
        ft->tbl[i] = sin(i * step);
    }
    return SP_OK;
}

void sp_gen_triangle(sp_data *sp, sp_ftbl *ft)
{
    unsigned int i;
    unsigned int counter;
    SPFLOAT incr;
    int step;

    incr = 1.0f / (SPFLOAT)ft->size;
    incr *= 2;

    step = 1;

    counter = 0;

    for (i = 0; i < ft->size; i++) {
        if (i == ft->size / 2) {
            step = -1;
        }
        ft->tbl[i] = (2.f*(counter * incr) - 1.f);
        counter += step;
    }
}

void sp_gen_composite(sp_data *sp, sp_ftbl *ft, const char *argstring)
{
    SPFLOAT phs, inc, amp, dc, tpdlen;
    int i, n;
    sp_ftbl *args;

    sp_ftbl_create(sp, &args, 1);
    sp_gen_vals(sp, args, argstring);

    tpdlen = 2 * M_PI / (SPFLOAT) ft->size;

    for (n = 0; n < args->size; n += 4) {
        inc = args->tbl[n] * tpdlen;
        amp = args->tbl[n + 1];
        phs = args->tbl[n + 2] * tpd360;
        dc = args->tbl[n + 3];

        for (i = 0; i <ft->size ; i++) {
            ft->tbl[i] += (SPFLOAT) (sin(phs) * amp + dc);
            if ((phs += inc) >= 2 * M_PI) phs -= 2 * M_PI;
        }
    }

    sp_ftbl_destroy(&args);
}

void sp_gen_sinesum(sp_data *sp, sp_ftbl *ft, const char *argstring)
{
    sp_ftbl *args;
    int32_t phs;
    SPFLOAT amp;
    int32_t flen;
    SPFLOAT tpdlen;
    int32_t i, n;

    sp_ftbl_create(sp, &args, 1);
    sp_gen_vals(sp, args, argstring);
    flen = (int32_t)ft->size;
    tpdlen = 2.0 * M_PI / (SPFLOAT) flen;

    for (i = (int32_t)args->size; i > 0; i--) {
        amp = args->tbl[i - 1];
        if (amp != 0) {
            for (phs = 0, n = 0; n < ft->size; n++) {
                ft->tbl[n] += sin(phs * tpdlen) * amp;
                phs += i;
                phs %= flen;
            }
        }
    }
    sp_ftbl_destroy(&args);
}

void sp_ftbl_fftcut(sp_ftbl *ft, int cut)
{
    kiss_fftr_cfg fft, ifft;
    kiss_fft_cpx *tmp;
    int i;
    SPFLOAT scale;

    fft = kiss_fftr_alloc(ft->size, 0, NULL, NULL);
    ifft = kiss_fftr_alloc(ft->size, 1, NULL, NULL);
    tmp = malloc(sizeof(kiss_fft_cpx) * ft->size);

    kiss_fftr(fft, ft->tbl, tmp);

    for (i = cut; i < (ft->size / 2); i++) {
        tmp[i].r = 0;
        tmp[i].i = 0;
    }

    kiss_fftri(ifft, tmp, ft->tbl);

    scale = 1.0 / ft->size;
    for (i = 0; i < ft->size; i++) {
        ft->tbl[i] *= scale;
    }

    free(tmp);
    kiss_fftr_free(fft);
    kiss_fftr_free(ifft);
}