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/*
* Copyright (C) 2003-2011 The Music Player Daemon Project
* http://www.musicpd.org
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "config.h"
#include "pcm_resample_internal.h"
#include <assert.h>
void
pcm_resample_fallback_init(struct pcm_resample_state *state)
{
pcm_buffer_init(&state->buffer);
}
void
pcm_resample_fallback_deinit(struct pcm_resample_state *state)
{
pcm_buffer_deinit(&state->buffer);
}
/* resampling code blatantly ripped from ESD */
const int16_t *
pcm_resample_fallback_16(struct pcm_resample_state *state,
unsigned channels,
unsigned src_rate,
const int16_t *src_buffer, size_t src_size,
unsigned dest_rate,
size_t *dest_size_r)
{
unsigned src_pos, dest_pos = 0;
unsigned src_frames = src_size / channels / sizeof(*src_buffer);
unsigned dest_frames =
(src_frames * dest_rate + src_rate - 1) / src_rate;
unsigned dest_samples = dest_frames * channels;
size_t dest_size = dest_samples * sizeof(*src_buffer);
int16_t *dest_buffer = pcm_buffer_get(&state->buffer, dest_size);
assert((src_size % (sizeof(*src_buffer) * channels)) == 0);
switch (channels) {
case 1:
while (dest_pos < dest_samples) {
src_pos = dest_pos * src_rate / dest_rate;
dest_buffer[dest_pos++] = src_buffer[src_pos];
}
break;
case 2:
while (dest_pos < dest_samples) {
src_pos = dest_pos * src_rate / dest_rate;
src_pos &= ~1;
dest_buffer[dest_pos++] = src_buffer[src_pos];
dest_buffer[dest_pos++] = src_buffer[src_pos + 1];
}
break;
}
*dest_size_r = dest_size;
return dest_buffer;
}
const int32_t *
pcm_resample_fallback_32(struct pcm_resample_state *state,
unsigned channels,
unsigned src_rate,
const int32_t *src_buffer, size_t src_size,
unsigned dest_rate,
size_t *dest_size_r)
{
unsigned src_pos, dest_pos = 0;
unsigned src_frames = src_size / channels / sizeof(*src_buffer);
unsigned dest_frames =
(src_frames * dest_rate + src_rate - 1) / src_rate;
unsigned dest_samples = dest_frames * channels;
size_t dest_size = dest_samples * sizeof(*src_buffer);
int32_t *dest_buffer = pcm_buffer_get(&state->buffer, dest_size);
assert((src_size % (sizeof(*src_buffer) * channels)) == 0);
switch (channels) {
case 1:
while (dest_pos < dest_samples) {
src_pos = dest_pos * src_rate / dest_rate;
dest_buffer[dest_pos++] = src_buffer[src_pos];
}
break;
case 2:
while (dest_pos < dest_samples) {
src_pos = dest_pos * src_rate / dest_rate;
src_pos &= ~1;
dest_buffer[dest_pos++] = src_buffer[src_pos];
dest_buffer[dest_pos++] = src_buffer[src_pos + 1];
}
break;
}
*dest_size_r = dest_size;
return dest_buffer;
}
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