tst_cffa.c

#ifndef ARDUINO
// tst_cffa.c - test complex FIR-filterbank analysis

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <time.h>
#include <ctype.h>

#include <sigpro.h>
#include "chapro.h"

typedef struct {
    char *ifn, *ofn, cs, mat;
    double rate;
    float *iwav, *owav;
    int32_t *siz;
    int32_t iod, nwav, nsmp, mseg, nseg, oseg, pseg;
    void **out;
} I_O;

/***********************************************************/

// initialize io

static void
init_wav(I_O *io)
{
    /* impulse input */
    io->nwav = round(io->rate);
    io->iwav = (float *) calloc(io->nwav, sizeof(float));
    fprintf(stdout, "impulse response: \n");
    io->ofn = "test/tst_cffa.mat";
    io->iwav[0] = 1;
    io->nsmp = io->nwav;
    io->mseg = 1;
    io->nseg = 1;
}

static void
write_waves(I_O *io, CHA_PTR cp, int c)
{
    char *ft;
    float r[1], *x, *y;
    int   n;
    static VAR *vl;

    ft = "MAT";
    fprintf(stdout, "%s output: %s\n", ft, io->ofn);
    remove(io->ofn);
    n = io->nwav;
    x = io->iwav;
    y = io->owav;
    r[0] = (float) io->rate;
    vl = sp_var_alloc(3);
    sp_var_add(vl, "rate", r, 1, 1, "f4");
    sp_var_add(vl,    "x", x, n, 1, "f4");
    sp_var_add(vl,    "y", y, n, c, "f4c");
    sp_mat_save(io->ofn, vl);
    sp_var_clear(vl);
}

/***********************************************************/

// specify filterbank center frequecies and bandwidths

static int
cross_freq(double *cf, double sr)
{
    int i, nh, nc, nm = 5;
    double fmin = 250, fmid = 1000, bpo = 3;

    nh = (int) floor(log2((float)sr / 2000) * bpo);
    nc = nh + nm;
    for (i = 0; i < nm; i++) {
        cf[i] = fmin + i * (fmid - fmin)  / (nm - 0.5);
    }
    for (i = 0; i < nh; i++) {
        cf[i + nm] = fmid * pow(2.0, (i + 0.5) / bpo);
    }

    return (nc + 1); // return number of channels = crossovers + 1
}

/***********************************************************/

// prepare CFIR filterbank

static void
prepare_filterbank(CHA_PTR cp)
{
    double cf[32];
    int nc; 
    static double sr = 24000;   // sampling rate (Hz)
    static int    nw = 256;     // window size
    static int    cs = 32;      // chunk size
    static int    wt = 0;       // window type: 0=Hamming, 1=Blackman

    // prepare CFIRFB
    nc = cross_freq(cf, sr);
    cha_cfirfb_prepare(cp, cf, nc, sr, nw, wt, cs);
}

// prepare signal processing

static void
prepare(I_O *io, CHA_PTR cp)
{
    double fs;
    int nc, ns, nw;

    prepare_filterbank(cp);
    fs = CHA_DVAR[_fs];
    nc = CHA_IVAR[_nc];
    ns = CHA_IVAR[_ns];
    nw = CHA_IVAR[_nw];
    // initialize waveform
    io->rate = fs * 1000;
    init_wav(io);
    ns = io->nsmp;
    // output buffer
    io->owav = (float *) calloc(nc * ns * 2, sizeof(float));
    // report
    fprintf(stdout, "CHA cfirfb_analyze: sampling rate=%.1f kHz, ", fs);
    fprintf(stdout, "CFIRFB: nw=%d \n", nw);
}

// unscramble channel outputs
static void
unscramble_out(float *y, float *z, int nc, int ns, int cs, int j)
{
    int k;

    for (k = 0; k < nc; k++) {
        fcopy(y + j * cs + k * ns, z + k * cs, cs);
    }
}

// process signal

static void
process(I_O *io, CHA_PTR cp)
{
    float *x, *y, *z;
    int j, nc, cs, ns, nk;

    // initialize i/o pointers
    x = io->iwav;
    y = io->owav;
    z = CHA_CB;
    ns = io->nsmp;
    nc = CHA_IVAR[_nc];
    // process FIR filterbank
    cs = CHA_IVAR[_cs]; // chunk size
    nk = ns / cs;       // number of chunks
    for (j = 0; j < nk; j++) {
        cha_cfirfb_analyze(cp, x + j * cs, z, cs);
        unscramble_out(y, z, nc, ns * 2, cs * 2, j);
    }
}

// clean up io

static void
cleanup(I_O *io, CHA_PTR cp)
{
    write_waves(io, cp, CHA_IVAR[_nc]);
    cha_cleanup(cp);
}

/***********************************************************/

int
main(int ac, char *av[])
{
    static I_O io;
    static void *cp[NPTR] = {0};

    prepare(&io, cp);
    process(&io, cp);
    cleanup(&io, cp);
    return (0);
}
#endif