ref: 579fae4ab7d37423aee4d9cdf7a29f9d96c2b764
dir: /src/example4.c/
/* Simple example of using SoX libraries
*
* Copyright (c) 2009 robs@users.sourceforge.net
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* This program 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 General
* Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "sox.h"
#include <stdio.h>
/* Concatenate audio files. Note that the files must have the same number
* of channels and the same sample rate.
*
* Usage: example4 input-1 input-2 [... input-n] output
*/
#define check(x) do if (!(x)) { \
fprintf(stderr, "check failed: %s\n", #x); goto error; } while (0)
int main(int argc, char * argv[])
{
sox_format_t * output = NULL;
int i;
check(argc >= 1 + 2 + 1); /* Need at least 2 input files + 1 output file. */
check(sox_init() == SOX_SUCCESS);
/* Defer openning the output file as we want to set its characteristics
* based on those of the input files. */
for (i = 1; i < argc - 1; ++i) { /* For each input file... */
sox_format_t * input;
static sox_signalinfo_t signal; /* static quashes `uninitialised' warning.*/
/* The (maximum) number of samples that we shall read/write at a time;
* chosen as a rough match to typical operating system I/O buffer size: */
#define MAX_SAMPLES (size_t)2048
sox_sample_t samples[MAX_SAMPLES]; /* Temporary store whilst copying. */
size_t number_read;
/* Open this input file: */
check(input = sox_open_read(argv[i], NULL, NULL, NULL));
if (i == 1) { /* If this is the first input file... */
/* Open the output file using the same signal and encoding character-
* istics as the first input file. Note that here, input->signal.length
* will not be equal to the output file length so we are relying on
* libSoX to set the output length correctly (i.e. non-seekable output
* is not catered for); an alternative would be to first calculate the
* output length by summing the lengths of the input files and modifying
* the second parameter to sox_open_write accordingly. */
check(output = sox_open_write(argv[argc - 1],
&input->signal, &input->encoding, NULL, NULL, NULL));
/* Also, we'll store the signal characteristics of the first file
* so that we can check that these match those of the other inputs: */
signal = input->signal;
}
else { /* Second or subsequent input file... */
/* Check that this input file's signal matches that of the first file: */
check(input->signal.channels == signal.channels);
check(input->signal.rate == signal.rate);
}
/* Copy all of the audio from this input file to the output file: */
while ((number_read = sox_read(input, samples, MAX_SAMPLES)))
check(sox_write(output, samples, number_read) == number_read);
check(sox_close(input) == SOX_SUCCESS); /* Finished with this input file.*/
}
check(sox_close(output) == SOX_SUCCESS); /* Finished with the output file. */
output = NULL;
check(sox_quit() == SOX_SUCCESS);
return 0;
error: /* Truncate output file on error: */
if (output) {
FILE * f;
sox_close(output);
if ((f = fopen(argv[argc - 1], "w"))) fclose(f);
}
return 1;
}