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#include <stdlib.h>
#include <assert.h>
#include <samplerate.h>
#include "resampler.h"
#include "sconv.h"
struct resampler {
struct pa_sample_spec i_ss, o_ss;
float* i_buf, *o_buf;
unsigned i_alloc, o_alloc;
size_t i_sz, o_sz;
int channels;
convert_to_float32_func_t to_float32_func;
convert_from_float32_func_t from_float32_func;
SRC_STATE *src_state;
};
struct resampler* resampler_new(const struct pa_sample_spec *a, const struct pa_sample_spec *b) {
struct resampler *r;
int err;
assert(a && b && pa_sample_spec_valid(a) && pa_sample_spec_valid(b));
if (a->channels != b->channels && a->channels != 1 && b->channels != 1)
goto fail;
if (a->format == PA_SAMPLE_ALAW || a->format == PA_SAMPLE_ULAW || b->format == PA_SAMPLE_ALAW || b->format == PA_SAMPLE_ULAW)
goto fail;
r = malloc(sizeof(struct resampler));
assert(r);
r->channels = a->channels;
if (b->channels < r->channels)
r->channels = b->channels;
r->i_buf = r->o_buf = NULL;
r->i_alloc = r->o_alloc = 0;
if (a->rate != b->rate) {
r->src_state = src_new(SRC_SINC_FASTEST, r->channels, &err);
if (err != 0 || !r->src_state)
goto fail;
} else
r->src_state = NULL;
r->i_ss = *a;
r->o_ss = *b;
r->i_sz = pa_sample_size(a);
r->o_sz = pa_sample_size(b);
r->to_float32_func = get_convert_to_float32_function(a->format);
r->from_float32_func = get_convert_from_float32_function(b->format);
assert(r->to_float32_func && r->from_float32_func);
return r;
fail:
if (r)
free(r);
return NULL;
}
void resampler_free(struct resampler *r) {
assert(r);
if (r->src_state)
src_delete(r->src_state);
free(r->i_buf);
free(r->o_buf);
free(r);
}
size_t resampler_request(struct resampler *r, size_t out_length) {
assert(r && (out_length % r->o_sz) == 0);
return (((out_length / r->o_sz)*r->i_ss.rate)/r->o_ss.rate) * r->i_sz;
}
void resampler_run(struct resampler *r, const struct memchunk *in, struct memchunk *out) {
unsigned i_nchannels, o_nchannels, ins, ons, eff_ins, eff_ons;
float *cbuf;
assert(r && in && out && in->length && in->memblock && (in->length % r->i_sz) == 0);
/* How many input samples? */
ins = in->length/r->i_sz;
/* How much space for output samples? */
if (r->src_state)
ons = (ins*r->o_ss.rate/r->i_ss.rate)+1024;
else
ons = ins;
/* How many channels? */
if (r->i_ss.channels == r->o_ss.channels) {
i_nchannels = o_nchannels = 1;
eff_ins = ins*r->i_ss.channels; /* effective samples */
eff_ons = ons*r->o_ss.channels;
} else {
i_nchannels = r->i_ss.channels;
o_nchannels = r->o_ss.channels;
eff_ins = ins;
eff_ons = ons;
}
out->memblock = memblock_new(out->length = (ons*r->o_sz));
out->index = 0;
assert(out->memblock);
if (r->i_alloc < eff_ins)
r->i_buf = realloc(r->i_buf, sizeof(float) * (r->i_alloc = eff_ins));
assert(r->i_buf);
r->to_float32_func(eff_ins, in->memblock->data+in->index, i_nchannels, r->i_buf);
if (r->src_state) {
int ret;
SRC_DATA data;
if (r->o_alloc < eff_ons)
r->o_buf = realloc(r->o_buf, sizeof(float) * (r->o_alloc = eff_ons));
assert(r->o_buf);
data.data_in = r->i_buf;
data.input_frames = ins;
data.data_out = r->o_buf;
data.output_frames = ons;
data.src_ratio = (double) r->o_ss.rate / r->i_ss.rate;
data.end_of_input = 0;
ret = src_process(r->src_state, &data);
assert(ret == 0);
assert((unsigned) data.input_frames_used == ins);
cbuf = r->o_buf;
ons = data.output_frames_gen;
if (r->i_ss.channels == r->o_ss.channels)
eff_ons = ons*r->o_ss.channels;
else
eff_ons = ons;
} else
cbuf = r->i_buf;
r->from_float32_func(eff_ons, cbuf, out->memblock->data+out->index, o_nchannels);
out->length = ons*r->o_sz;
}
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