/* libSoX effect: Input audio from a file   (c) 2008 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" typedef struct {sox_format_t * file;} priv_t; static int getopts(sox_effect_t * effp, int argc, char * * argv){  priv_t * p = (priv_t *)effp->priv;  if (argc != 2 || !(p->file = (sox_format_t *)argv[1]) || p->file->mode != 'r')    return SOX_EOF;  return SOX_SUCCESS;} static int drain(    sox_effect_t * effp, sox_sample_t * obuf, size_t * osamp){  priv_t * p = (priv_t *)effp->priv;   /* ensure that *osamp is a multiple of the number of channels. */  *osamp -= *osamp % effp->out_signal.channels;   /* Read up to *osamp samples into obuf; store the actual number read   * back to *osamp */  *osamp = sox_read(p->file, obuf, *osamp);   /* sox_read may return a number that is less than was requested; only if   * 0 samples is returned does it indicate that end-of-file has been reached   * or an error has occurred */  if (!*osamp && p->file->sox_errno)    lsx_fail("%s: %s", p->file->filename, p->file->sox_errstr);  return *osamp? SOX_SUCCESS : SOX_EOF;} sox_effect_handler_t const * lsx_input_effect_fn(void){  static sox_effect_handler_t handler = {    "input", NULL, SOX_EFF_MCHAN | SOX_EFF_LENGTH | SOX_EFF_INTERNAL,    getopts, NULL, NULL, drain, NULL, NULL, sizeof(priv_t)  };  return &handler;}