mpd/src/pcm_resample_libsamplerate.c
Max Kellermann fd81e7e3b6 libsamplerate: use g_ascii_strncasecmp() instead of strncasecmp()
strncasecmp() is locale dependent, making it a bad choice for internal
string comparisons.
2009-04-28 09:42:05 +02:00

238 lines
6.2 KiB
C

/*
* Copyright (C) 2003-2009 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 "pcm_resample_internal.h"
#include "conf.h"
#include "config.h"
#include <glib.h>
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#undef G_LOG_DOMAIN
#define G_LOG_DOMAIN "pcm"
void
pcm_resample_lsr_deinit(struct pcm_resample_state *state)
{
if (state->state != NULL)
state->state = src_delete(state->state);
pcm_buffer_deinit(&state->in);
pcm_buffer_deinit(&state->out);
pcm_buffer_deinit(&state->buffer);
}
static int pcm_resample_get_converter(void)
{
const char *conf = config_get_string(CONF_SAMPLERATE_CONVERTER, NULL);
long convalgo;
char *test;
const char *test2;
size_t len;
if (!conf) {
convalgo = SRC_SINC_FASTEST;
goto out;
}
convalgo = strtol(conf, &test, 10);
if (*test == '\0' && src_get_name(convalgo))
goto out;
len = strlen(conf);
for (convalgo = 0 ; ; convalgo++) {
test2 = src_get_name(convalgo);
if (!test2) {
convalgo = SRC_SINC_FASTEST;
break;
}
if (g_ascii_strncasecmp(test2, conf, len) == 0)
goto out;
}
g_warning("unknown samplerate converter \"%s\"", conf);
out:
g_debug("selecting samplerate converter \"%s\"",
src_get_name(convalgo));
return convalgo;
}
static void
pcm_resample_set(struct pcm_resample_state *state,
uint8_t channels, unsigned src_rate, unsigned dest_rate)
{
static int convalgo = -1;
int error;
SRC_DATA *data = &state->data;
if (convalgo < 0)
convalgo = pcm_resample_get_converter();
/* (re)set the state/ratio if the in or out format changed */
if (channels == state->prev.channels &&
src_rate == state->prev.src_rate &&
dest_rate == state->prev.dest_rate)
return;
state->error = false;
state->prev.channels = channels;
state->prev.src_rate = src_rate;
state->prev.dest_rate = dest_rate;
if (state->state)
state->state = src_delete(state->state);
state->state = src_new(convalgo, channels, &error);
if (!state->state) {
g_warning("cannot create new libsamplerate state: %s",
src_strerror(error));
state->error = true;
return;
}
data->src_ratio = (double)dest_rate / (double)src_rate;
g_debug("setting samplerate conversion ratio to %.2lf",
data->src_ratio);
src_set_ratio(state->state, data->src_ratio);
}
const int16_t *
pcm_resample_lsr_16(struct pcm_resample_state *state,
uint8_t channels,
unsigned src_rate,
const int16_t *src_buffer, size_t src_size,
unsigned dest_rate,
size_t *dest_size_r)
{
SRC_DATA *data = &state->data;
size_t data_in_size;
size_t data_out_size;
int error;
int16_t *dest_buffer;
assert((src_size % (sizeof(*src_buffer) * channels)) == 0);
pcm_resample_set(state, channels, src_rate, dest_rate);
/* there was an error previously, and nothing has changed */
if (state->error)
return NULL;
data->input_frames = src_size / sizeof(*src_buffer) / channels;
data_in_size = data->input_frames * sizeof(float) * channels;
data->data_in = pcm_buffer_get(&state->in, data_in_size);
data->output_frames = (src_size * dest_rate + src_rate - 1) / src_rate;
data_out_size = data->output_frames * sizeof(float) * channels;
data->data_out = pcm_buffer_get(&state->out, data_out_size);
src_short_to_float_array(src_buffer, data->data_in,
data->input_frames * channels);
error = src_process(state->state, data);
if (error) {
g_warning("error processing samples with libsamplerate: %s",
src_strerror(error));
state->error = true;
return NULL;
}
*dest_size_r = data->output_frames_gen *
sizeof(*dest_buffer) * channels;
dest_buffer = pcm_buffer_get(&state->buffer, *dest_size_r);
src_float_to_short_array(data->data_out, dest_buffer,
data->output_frames_gen * channels);
return dest_buffer;
}
#ifdef HAVE_LIBSAMPLERATE_NOINT
/* libsamplerate introduced these functions in v0.1.3 */
static void
src_int_to_float_array(const int *in, float *out, int len)
{
while (len-- > 0)
*out++ = *in++ / (float)(1 << (24 - 1));
}
static void
src_float_to_int_array (const float *in, int *out, int len)
{
while (len-- > 0)
*out++ = *in++ * (float)(1 << (24 - 1));
}
#endif
const int32_t *
pcm_resample_lsr_32(struct pcm_resample_state *state,
uint8_t channels,
unsigned src_rate,
const int32_t *src_buffer, size_t src_size,
unsigned dest_rate,
size_t *dest_size_r)
{
SRC_DATA *data = &state->data;
size_t data_in_size;
size_t data_out_size;
int error;
int32_t *dest_buffer;
assert((src_size % (sizeof(*src_buffer) * channels)) == 0);
pcm_resample_set(state, channels, src_rate, dest_rate);
/* there was an error previously, and nothing has changed */
if (state->error)
return NULL;
data->input_frames = src_size / sizeof(*src_buffer) / channels;
data_in_size = data->input_frames * sizeof(float) * channels;
data->data_in = pcm_buffer_get(&state->in, data_in_size);
data->output_frames = (src_size * dest_rate + src_rate - 1) / src_rate;
data_out_size = data->output_frames * sizeof(float) * channels;
data->data_out = pcm_buffer_get(&state->out, data_out_size);
src_int_to_float_array(src_buffer, data->data_in,
data->input_frames * channels);
error = src_process(state->state, data);
if (error) {
g_warning("error processing samples with libsamplerate: %s",
src_strerror(error));
state->error = true;
return NULL;
}
*dest_size_r = data->output_frames_gen *
sizeof(*dest_buffer) * channels;
dest_buffer = pcm_buffer_get(&state->buffer, *dest_size_r);
src_float_to_int_array(data->data_out, dest_buffer,
data->output_frames_gen * channels);
return dest_buffer;
}