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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/ffmpeg/avcodec.h"
#include <pulsecore/resampler.h>
struct ffmpeg_data { /* data specific to ffmpeg */
struct AVResampleContext *state;
};
static unsigned ffmpeg_resample(pa_resampler *r, const pa_memchunk *input, unsigned in_n_frames, pa_memchunk *output, unsigned *out_n_frames) {
unsigned used_frames = 0, c;
int previous_consumed_frames = -1;
struct ffmpeg_data *ffmpeg_data;
pa_assert(r);
pa_assert(input);
pa_assert(output);
pa_assert(out_n_frames);
ffmpeg_data = r->impl.data;
for (c = 0; c < r->work_channels; c++) {
unsigned u;
pa_memblock *b, *w;
int16_t *p, *t, *k, *q, *s;
int consumed_frames;
/* Allocate a new block */
b = pa_memblock_new(r->mempool, in_n_frames * sizeof(int16_t));
p = pa_memblock_acquire(b);
/* Now copy the input data, splitting up channels */
t = (int16_t*) pa_memblock_acquire_chunk(input) + c;
k = p;
for (u = 0; u < in_n_frames; u++) {
*k = *t;
t += r->work_channels;
k ++;
}
pa_memblock_release(input->memblock);
/* Allocate buffer for the result */
w = pa_memblock_new(r->mempool, *out_n_frames * sizeof(int16_t));
q = pa_memblock_acquire(w);
/* Now, resample */
used_frames = (unsigned) av_resample(ffmpeg_data->state,
q, p,
&consumed_frames,
(int) in_n_frames, (int) *out_n_frames,
c >= (unsigned) (r->work_channels-1));
pa_memblock_release(b);
pa_memblock_unref(b);
pa_assert(consumed_frames <= (int) in_n_frames);
pa_assert(previous_consumed_frames == -1 || consumed_frames == previous_consumed_frames);
previous_consumed_frames = consumed_frames;
/* And place the results in the output buffer */
s = (int16_t *) pa_memblock_acquire_chunk(output) + c;
for (u = 0; u < used_frames; u++) {
*s = *q;
q++;
s += r->work_channels;
}
pa_memblock_release(output->memblock);
pa_memblock_release(w);
pa_memblock_unref(w);
}
*out_n_frames = used_frames;
return in_n_frames - previous_consumed_frames;
}
static void ffmpeg_free(pa_resampler *r) {
struct ffmpeg_data *ffmpeg_data;
pa_assert(r);
ffmpeg_data = r->impl.data;
if (ffmpeg_data->state)
av_resample_close(ffmpeg_data->state);
}
int pa_resampler_ffmpeg_init(pa_resampler *r) {
struct ffmpeg_data *ffmpeg_data;
pa_assert(r);
ffmpeg_data = pa_xnew(struct ffmpeg_data, 1);
/* We could probably implement different quality levels by
* adjusting the filter parameters here. However, ffmpeg
* internally only uses these hardcoded values, so let's use them
* here for now as well until ffmpeg makes this configurable. */
if (!(ffmpeg_data->state = av_resample_init((int) r->o_ss.rate, (int) r->i_ss.rate, 16, 10, 0, 0.8))) {
pa_xfree(ffmpeg_data);
return -1;
}
r->impl.free = ffmpeg_free;
r->impl.resample = ffmpeg_resample;
r->impl.data = (void *) ffmpeg_data;
return 0;
}
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