aboutsummaryrefslogtreecommitdiffstats
path: root/src/pcm_resample_libsamplerate.c
diff options
context:
space:
mode:
authorMax Kellermann <max@duempel.org>2008-10-23 20:00:51 +0200
committerMax Kellermann <max@duempel.org>2008-10-23 20:00:51 +0200
commit6b1c54ef9646abddfbd4960c207b32426300a90c (patch)
tree5b3ae6bf5fc377cf9c705c85948ab5b85e31743c /src/pcm_resample_libsamplerate.c
parent098991f8e8a974d2eee39645fa23c43a4c8b06c1 (diff)
downloadmpd-6b1c54ef9646abddfbd4960c207b32426300a90c.tar.gz
mpd-6b1c54ef9646abddfbd4960c207b32426300a90c.tar.xz
mpd-6b1c54ef9646abddfbd4960c207b32426300a90c.zip
pcm_utils: moved code to pcm_resample.c
Separate the resampling code from the rest of pcm_utils.c. Create two sub-libraries: pcm_resample_libsamplerate.c and pcm_resample_fallback.c.
Diffstat (limited to '')
-rw-r--r--src/pcm_resample_libsamplerate.c140
1 files changed, 140 insertions, 0 deletions
diff --git a/src/pcm_resample_libsamplerate.c b/src/pcm_resample_libsamplerate.c
new file mode 100644
index 000000000..5321c0e0b
--- /dev/null
+++ b/src/pcm_resample_libsamplerate.c
@@ -0,0 +1,140 @@
+/* the Music Player Daemon (MPD)
+ * Copyright (C) 2003-2007 by Warren Dukes (warren.dukes@gmail.com)
+ * Copyright (C) 2008 Max Kellermann <max@duempel.org>
+ * This project's homepage is: 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include "pcm_resample.h"
+#include "conf.h"
+#include "log.h"
+#include "utils.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+static int pcm_resample_get_converter(void)
+{
+ const char *conf = getConfigParamValue(CONF_SAMPLERATE_CONVERTER);
+ 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 (strncasecmp(test2, conf, len) == 0)
+ goto out;
+ }
+
+ ERROR("unknown samplerate converter \"%s\"\n", conf);
+out:
+ DEBUG("selecting samplerate converter \"%s\"\n",
+ src_get_name(convalgo));
+
+ return convalgo;
+}
+
+size_t
+pcm_resample_16(uint8_t channels,
+ unsigned src_rate,
+ const int16_t *src_buffer, size_t src_size,
+ unsigned dest_rate,
+ int16_t *dest_buffer, size_t dest_size,
+ struct pcm_resample_state *state)
+{
+ static int convalgo = -1;
+ SRC_DATA *data = &state->data;
+ size_t data_in_size;
+ size_t data_out_size;
+ int error;
+
+ 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) {
+ 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) {
+ ERROR("cannot create new libsamplerate state: %s\n",
+ src_strerror(error));
+ state->error = true;
+ return 0;
+ }
+
+ data->src_ratio = (double)dest_rate / (double)src_rate;
+ DEBUG("setting samplerate conversion ratio to %.2lf\n",
+ data->src_ratio);
+ src_set_ratio(state->state, data->src_ratio);
+ }
+
+ /* there was an error previously, and nothing has changed */
+ if (state->error)
+ return 0;
+
+ data->input_frames = src_size / 2 / channels;
+ data_in_size = data->input_frames * sizeof(float) * channels;
+ if (data_in_size > state->data_in_size) {
+ state->data_in_size = data_in_size;
+ data->data_in = xrealloc(data->data_in, data_in_size);
+ }
+
+ data->output_frames = dest_size / 2 / channels;
+ data_out_size = data->output_frames * sizeof(float) * channels;
+ if (data_out_size > state->data_out_size) {
+ state->data_out_size = data_out_size;
+ data->data_out = xrealloc(data->data_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) {
+ ERROR("error processing samples with libsamplerate: %s\n",
+ src_strerror(error));
+ state->error = true;
+ return 0;
+ }
+
+ src_float_to_short_array(data->data_out, dest_buffer,
+ data->output_frames_gen * channels);
+
+ return data->output_frames_gen * 2 * channels;
+}