98 lines
4.3 KiB
C
98 lines
4.3 KiB
C
/* SoX Resampler Library Copyright (c) 2007-12 robs@users.sourceforge.net
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* Licence for this file: LGPL v2.1 See LICENCE for details. */
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/* Example 3: extends example 2 with multiple channels, multiple datatypes,
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* and other options.
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*
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* The application provides an input function, called on demand by libsoxr, in
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* response to calls to soxr_output(); compared to the `process' approach
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* (illustrated in example 2) this requires that the application implements
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* less logic, but one more function.
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*
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* The eight arguments (which are optional, from last to first) are:
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* INPUT-RATE As example 2
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* OUTPUT-RATE Ditto
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* NUM-CHANNELS Number of interleaved channels
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* IN-DATATYPE# 0:float32 1:float64 2:int32 3:int16
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* OUT-DATATYPE# Ditto
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* Q-RECIPE Quality recipe (in hex) See soxr.h
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* Q-FLAGS Quality flags (in hex) See soxr.h
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* USE-THREADS 1 to use multi-threading (where available)
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*/
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#include <soxr.h>
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#include "examples-common.h"
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typedef struct {void * ibuf; size_t isize;} input_context_t;
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static size_t input_fn(input_context_t * p, soxr_cbuf_t * buf, size_t len)
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{
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/* Read one block into the buffer, ready to be input to the resampler: */
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len = fread(p->ibuf, p->isize, len, stdin); /* Actual len read may be less. */
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/* Inform the resampler of the data's whereabouts (which could be anywhere, in
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* a freshly malloc'd buffer, for example): */
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*buf = (!len && ferror(stdin))? NULL : p->ibuf; /* NULL if error occurred. */
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return len; /* # of samples per channel to input. */
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}
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int main(int n, char const * arg[])
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{
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char const * const arg0 = n? --n, *arg++ : "";
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double const irate = n? --n, atof(*arg++) : 96000.;
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double const orate = n? --n, atof(*arg++) : 44100.;
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unsigned const chans = n? --n, (unsigned)atoi(*arg++) : 1;
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soxr_datatype_t const itype = n? --n, (soxr_datatype_t)atoi(*arg++) : 0;
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soxr_datatype_t const otype = n? --n, (soxr_datatype_t)atoi(*arg++) : 0;
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unsigned long const q_recipe= n? --n, strtoul(*arg++, 0, 16) : SOXR_HQ;
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unsigned long const q_flags = n? --n, strtoul(*arg++, 0, 16) : 0;
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int const use_threads = n? --n, atoi(*arg++) : 1;
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soxr_quality_spec_t const q_spec = soxr_quality_spec(q_recipe, q_flags);
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soxr_io_spec_t const io_spec = soxr_io_spec(itype, otype);
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soxr_runtime_spec_t const runtime_spec = soxr_runtime_spec(!use_threads);
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/* Allocate resampling input and output buffers in proportion to the input
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* and output rates: */
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#define buf_total_len 15000 /* In samples per channel. */
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size_t const osize = soxr_datatype_size(otype) * chans;
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size_t const isize = soxr_datatype_size(itype) * chans;
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size_t const olen = (size_t)(orate * buf_total_len / (irate + orate) + .5);
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size_t const ilen = buf_total_len - olen;
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void * const obuf = malloc(osize * olen);
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void * const ibuf = malloc(isize * ilen);
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input_context_t icontext;
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size_t odone, clips = 0;
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soxr_error_t error;
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/* Create a stream resampler: */
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soxr_t soxr = soxr_create(
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irate, orate, chans, /* Input rate, output rate, # of channels. */
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&error, /* To report any error during creation. */
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&io_spec, &q_spec, &runtime_spec);
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if (!error) { /* Register input_fn with the resampler: */
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icontext.ibuf = ibuf, icontext.isize = isize;
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error = soxr_set_input_fn(soxr, (soxr_input_fn_t)input_fn, &icontext, ilen);
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}
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if (!error) { /* If all is well, run the resampler: */
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USE_STD_STDIO;
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/* Resample in blocks: */
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do odone = soxr_output(soxr, obuf, olen);
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while (fwrite(obuf, osize, odone, stdout)); /* Consume output. */
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error = soxr_error(soxr); /* Check if any soxr error occurred. */
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clips = *soxr_num_clips(soxr); /* Can occur only with integer output. */
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}
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/* Tidy up: */
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soxr_delete(soxr);
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free(obuf), free(ibuf);
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/* Diagnostics: */
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fprintf(stderr, "%-26s %s; %lu clips; I/O: %s\n", arg0, soxr_strerror(error),
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(long unsigned)clips, errno? strerror(errno) : "no error");
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return error || errno;
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}
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