/* Effect: fir filter from coefs   Copyright (c) 2009 robs@users.sourceforge.net * * This library is free software; you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation; either version 2.1 of the License, or (at * your option) any later version. * * This library 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 Lesser * General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this library; if not, write to the Free Software Foundation, * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA */ #include "sox_i.h"#include "dft_filter.h" typedef struct {  dft_filter_priv_t  base;  char const         * filename;  double             * h;  int                n;} priv_t; static int soxcreate(sox_effect_t * effp, int argc, char * * argv){  priv_t             * p = (priv_t *)effp->priv;  dft_filter_priv_t  * b = &p->base;  double             d;  char               c;   b->filter_ptr = &b->filter;  --argc, ++argv;  if (!argc)    p->filename = "-"; /* default to stdin */  else if (argc == 1)    p->filename = argv[0], --argc;  else for (; argc && sscanf(*argv, "%lf%c", &d, &c) == 1; --argc, ++argv) {    p->n++;    p->h = lsx_realloc(p->h, p->n * sizeof(*p->h));    p->h[p->n - 1] = d;  }  return argc? lsx_usage(effp) : SOX_SUCCESS;} static int start(sox_effect_t * effp){  priv_t        * p = (priv_t *)effp->priv;  dft_filter_t  * f = p->base.filter_ptr;  double        d;  char          c;  int           i;   if (!f->num_taps) {    if (!p->n && p->filename) {      FILE * file = lsx_open_input_file(effp, p->filename, sox_true);      if (!file)        return SOX_EOF;      while ((i = fscanf(file, " #%*[^\n]%c", &c)) >= 0) {        if (i >= 1) continue; /* found and skipped a comment */        if (fscanf(file, "%lf", &d) > 0) {          /* found a coefficient value */          p->n++;          p->h = lsx_realloc(p->h, p->n * sizeof(*p->h));          p->h[p->n - 1] = d;        } else break; /* either EOF, or something went wrong                         (read or syntax error) */      }      if (!feof(file)) {        lsx_fail("error reading coefficient file");        if (file != stdin) fclose(file);        return SOX_EOF;      }      if (file != stdin) fclose(file);    }    lsx_report("%i coefficients", p->n);    if (!p->n)      return SOX_EFF_NULL;    if (effp->global_info->plot != sox_plot_off) {      char title[100];      sprintf(title, "SoX effect: fir (%d coefficients)", p->n);      lsx_plot_fir(p->h, p->n, effp->in_signal.rate,          effp->global_info->plot, title, -30., 30.);      free(p->h);      return SOX_EOF;    }    lsx_set_dft_filter(f, p->h, p->n, p->n >> 1);  }  return lsx_dft_filter_effect_fn()->start(effp);} sox_effect_handler_t const * lsx_fir_effect_fn(void){  static sox_effect_handler_t handler;  handler = *lsx_dft_filter_effect_fn();  handler.name = "fir";  handler.usage = "[coef-file|coefs]";  handler.getopts = soxcreate;  handler.start = start;  handler.priv_size = sizeof(priv_t);  return &handler;}