src/example6.c

   1 /* Simple example of using SoX libraries
   2  *
   3  * Copyright (c) 2007-14 robs@users.sourceforge.net
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License as published by the
   7  * Free Software Foundation; either version 2 of the License, or (at your
   8  * option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
  13  * Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18  */
  19
  20 #ifdef NDEBUG /* N.B. assert used with active statements so enable always. */
  21 #undef NDEBUG /* Must undef above assert.h or other that might include it. */
  22 #endif
  23
  24 #include "sox.h"
  25 #include "util.h"
  26 #include <stdio.h>
  27 #include <assert.h>
  28
  29 /*
  30  * Shows how to explicitly specify output file signal and encoding attributes.
  31  *
  32  * The example converts a given input file of any type to mono mu-law at 8kHz
  33  * sampling-rate (providing that this is supported by the given output file
  34  * type).
  35  *
  36  * For example:
  37  *
  38  *   sox -r 16k -n input.wav synth 8 sin 0:8k sin 8k:0 gain -1
  39  *   ./example6 input.wav output.wav
  40  *   soxi input.wav output.wav
  41  *
  42  * gives:
  43  *
  44  * Input File     : 'input.wav'
  45  * Channels       : 2
  46  * Sample Rate    : 16000
  47  * Precision      : 32-bit
  48  * Duration       : 00:00:08.00 = 128000 samples ~ 600 CDDA sectors
  49  * File Size      : 1.02M
  50  * Bit Rate       : 1.02M
  51  * Sample Encoding: 32-bit Signed Integer PCM
  52  *
  53  * Input File     : 'output.wav'
  54  * Channels       : 1
  55  * Sample Rate    : 8000
  56  * Precision      : 14-bit
  57  * Duration       : 00:00:08.00 = 64000 samples ~ 600 CDDA sectors
  58  * File Size      : 64.1k
  59  * Bit Rate       : 64.1k
  60  * Sample Encoding: 8-bit u-law
  61  */
  62
  63 int main(int argc, char * argv[])
  64 {
  65   static sox_format_t * in, * out; /* input and output files */
  66   sox_effects_chain_t * chain;
  67   sox_effect_t * e;
  68   char * args[10];
  69   sox_signalinfo_t interm_signal; /* @ intermediate points in the chain. */
  70   sox_encodinginfo_t out_encoding = {
  71     SOX_ENCODING_ULAW,
  72     8,
  73     0,
  74     sox_option_default,
  75     sox_option_default,
  76     sox_option_default,
  77     sox_false
  78   };
  79   sox_signalinfo_t out_signal = {
  80     8000,
  81     1,
  82     0,
  83     0,
  84     NULL
  85   };
  86
  87   assert(argc == 3);
  88   assert(sox_init() == SOX_SUCCESS);
  89   assert((in = sox_open_read(argv[1], NULL, NULL, NULL)));
  90   assert((out = sox_open_write(argv[2], &out_signal, &out_encoding, NULL, NULL, NULL)));
  91
  92   chain = sox_create_effects_chain(&in->encoding, &out->encoding);
  93
  94   interm_signal = in->signal; /* NB: deep copy */
  95
  96   e = sox_create_effect(sox_find_effect("input"));
  97   args[0] = (char *)in, assert(sox_effect_options(e, 1, args) == SOX_SUCCESS);
  98   assert(sox_add_effect(chain, e, &interm_signal, &in->signal) == SOX_SUCCESS);
  99   free(e);
 100
 101   if (in->signal.rate != out->signal.rate) {
 102     e = sox_create_effect(sox_find_effect("rate"));
 103     assert(sox_effect_options(e, 0, NULL) == SOX_SUCCESS);
 104     assert(sox_add_effect(chain, e, &interm_signal, &out->signal) == SOX_SUCCESS);
 105     free(e);
 106   }
 107
 108   if (in->signal.channels != out->signal.channels) {
 109     e = sox_create_effect(sox_find_effect("channels"));
 110     assert(sox_effect_options(e, 0, NULL) == SOX_SUCCESS);
 111     assert(sox_add_effect(chain, e, &interm_signal, &out->signal) == SOX_SUCCESS);
 112     free(e);
 113   }
 114
 115   e = sox_create_effect(sox_find_effect("output"));
 116   args[0] = (char *)out, assert(sox_effect_options(e, 1, args) == SOX_SUCCESS);
 117   assert(sox_add_effect(chain, e, &interm_signal, &out->signal) == SOX_SUCCESS);
 118   free(e);
 119
 120   sox_flow_effects(chain, NULL, NULL);
 121
 122   sox_delete_effects_chain(chain);
 123   sox_close(out);
 124   sox_close(in);
 125   sox_quit();
 126
 127   return 0;
 128 }