boo/soxr/examples/2-stream.C

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2016-03-23 05:33:14 +00:00
/* SoX Resampler Library Copyright (c) 2007-13 robs@users.sourceforge.net
* Licence for this file: LGPL v2.1 See LICENCE for details. */
/* Example 2: resample a raw, single-channel, floating-point data stream from
* stdin to stdout.
*
* The application uses the single function `soxr_process' for both input and
* output to/from the resampler; compared to the `input function' approach
* (illustrated in example 3) this requires that the application implements
* more logic, but one less function.
*
* Arguments are: INPUT-RATE OUTPUT-RATE
*/
#include <soxr.h>
#include "examples-common.h"
int main(int argc, char const * arg[])
{
double const irate = argc > 1? atof(arg[1]) : 96000.;
double const orate = argc > 2? atof(arg[2]) : 44100.;
/* Allocate resampling input and output buffers in proportion to the input
* and output rates: */
#define buf_total_len 15000 /* In samples. */
size_t const olen = (size_t)(orate * buf_total_len / (irate + orate) + .5);
size_t const ilen = buf_total_len - olen;
size_t const osize = sizeof(float), isize = osize;
void * obuf = malloc(osize * olen);
void * ibuf = malloc(isize * ilen);
size_t odone, written, need_input = 1;
soxr_error_t error;
/* Create a stream resampler: */
soxr_t soxr = soxr_create(
irate, orate, 1, /* Input rate, output rate, # of channels. */
&error, /* To report any error during creation. */
NULL, NULL, NULL); /* Use configuration defaults.*/
if (!error) { /* If all is well, run the resampler: */
USE_STD_STDIO;
/* Resample in blocks: */
do {
size_t ilen1 = 0;
if (need_input) {
/* Read one block into the buffer, ready to be resampled: */
ilen1 = fread(ibuf, isize, ilen, stdin);
if (!ilen1) { /* If the is no (more) input data available, */
free(ibuf); /* set ibuf to NULL, to indicate end-of-input */
ibuf = NULL; /* to the resampler. */
}
}
/* Copy data from the input buffer into the resampler, and resample
* to produce as much output as is possible to the given output buffer: */
error = soxr_process(soxr, ibuf, ilen1, NULL, obuf, olen, &odone);
written = fwrite(obuf, osize, odone, stdout); /* Consume output.*/
/* If the actual amount of data output is less than that requested, and
* we have not already reached the end of the input data, then supply some
* more input next time round the loop: */
need_input = odone < olen && ibuf;
} while (!error && (need_input || written));
}
/* Tidy up: */
soxr_delete(soxr);
free(obuf), free(ibuf);
/* Diagnostics: */
fprintf(stderr, "%-26s %s; I/O: %s\n", arg[0], soxr_strerror(error),
ferror(stdin) || ferror(stdout)? strerror(errno) : "no error");
return !!error;
}