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/***
This file is part of PulseAudio.
Copyright 2004-2006 Lennart Poettering
PulseAudio is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published
by the Free Software Foundation; either version 2.1 of the License,
or (at your option) any later version.
PulseAudio 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 Lesser General Public License
along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
***/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <pulse/xmalloc.h>
#include <pulsecore/resampler.h>
struct trivial_data { /* data specific to the trivial resampler */
unsigned o_counter;
unsigned i_counter;
};
static unsigned trivial_resample(pa_resampler *r, const pa_memchunk *input, unsigned in_n_frames, pa_memchunk *output, unsigned *out_n_frames) {
unsigned i_index, o_index;
void *src, *dst;
struct trivial_data *trivial_data;
pa_assert(r);
pa_assert(input);
pa_assert(output);
pa_assert(out_n_frames);
trivial_data = r->impl.data;
src = pa_memblock_acquire_chunk(input);
dst = pa_memblock_acquire_chunk(output);
for (o_index = 0;; o_index++, trivial_data->o_counter++) {
i_index = ((uint64_t) trivial_data->o_counter * r->i_ss.rate) / r->o_ss.rate;
i_index = i_index > trivial_data->i_counter ? i_index - trivial_data->i_counter : 0;
if (i_index >= in_n_frames)
break;
pa_assert_fp(o_index * r->w_fz < pa_memblock_get_length(output->memblock));
memcpy((uint8_t*) dst + r->w_fz * o_index, (uint8_t*) src + r->w_fz * i_index, (int) r->w_fz);
}
pa_memblock_release(input->memblock);
pa_memblock_release(output->memblock);
*out_n_frames = o_index;
trivial_data->i_counter += in_n_frames;
/* Normalize counters */
while (trivial_data->i_counter >= r->i_ss.rate) {
pa_assert(trivial_data->o_counter >= r->o_ss.rate);
trivial_data->i_counter -= r->i_ss.rate;
trivial_data->o_counter -= r->o_ss.rate;
}
return 0;
}
static void trivial_update_rates_or_reset(pa_resampler *r) {
struct trivial_data *trivial_data;
pa_assert(r);
trivial_data = r->impl.data;
trivial_data->i_counter = 0;
trivial_data->o_counter = 0;
}
int pa_resampler_trivial_init(pa_resampler *r) {
struct trivial_data *trivial_data;
pa_assert(r);
trivial_data = pa_xnew0(struct trivial_data, 1);
r->impl.resample = trivial_resample;
r->impl.update_rates = trivial_update_rates_or_reset;
r->impl.reset = trivial_update_rates_or_reset;
r->impl.data = trivial_data;
return 0;
}
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