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-rw-r--r--src/pcm_convert.c157
1 files changed, 157 insertions, 0 deletions
diff --git a/src/pcm_convert.c b/src/pcm_convert.c
new file mode 100644
index 000000000..283befd8c
--- /dev/null
+++ b/src/pcm_convert.c
@@ -0,0 +1,157 @@
+/*
+ * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include "pcm_convert.h"
+#include "pcm_channels.h"
+#include "pcm_format.h"
+#include "audio_format.h"
+
+#include <assert.h>
+#include <string.h>
+#include <math.h>
+#include <glib.h>
+
+#undef G_LOG_DOMAIN
+#define G_LOG_DOMAIN "pcm"
+
+void pcm_convert_init(struct pcm_convert_state *state)
+{
+ memset(state, 0, sizeof(*state));
+
+ pcm_resample_init(&state->resample);
+ pcm_dither_24_init(&state->dither);
+}
+
+static size_t
+pcm_convert_16(const struct audio_format *src_format,
+ const void *src_buffer, size_t src_size,
+ const struct audio_format *dest_format,
+ int16_t *dest_buffer,
+ struct pcm_convert_state *state)
+{
+ const int16_t *buf;
+ size_t len;
+ size_t dest_size = pcm_convert_size(src_format, src_size, dest_format);
+
+ assert(dest_format->bits == 16);
+
+ buf = pcm_convert_to_16(&state->dither, src_format->bits,
+ src_buffer, src_size, &len);
+ if (!buf)
+ g_error("pcm_convert_to_16() failed");
+
+ if (src_format->channels != dest_format->channels) {
+ buf = pcm_convert_channels_16(dest_format->channels,
+ src_format->channels,
+ buf, len, &len);
+ if (!buf)
+ g_error("pcm_convert_channels_16() failed");
+ }
+
+ if (src_format->sample_rate == dest_format->sample_rate) {
+ assert(dest_size >= len);
+ memcpy(dest_buffer, buf, len);
+ } else {
+ len = pcm_resample_16(dest_format->channels,
+ src_format->sample_rate, buf, len,
+ dest_format->sample_rate,
+ dest_buffer, dest_size,
+ &state->resample);
+ }
+
+ return len;
+}
+
+static size_t
+pcm_convert_24(const struct audio_format *src_format,
+ const void *src_buffer, size_t src_size,
+ const struct audio_format *dest_format,
+ int32_t *dest_buffer,
+ struct pcm_convert_state *state)
+{
+ const int32_t *buf;
+ size_t len;
+ size_t dest_size = pcm_convert_size(src_format, src_size, dest_format);
+
+ assert(dest_format->bits == 24);
+
+ buf = pcm_convert_to_24(src_format->bits,
+ src_buffer, src_size, &len);
+ if (!buf)
+ g_error("pcm_convert_to_24() failed");
+
+ if (src_format->channels != dest_format->channels) {
+ buf = pcm_convert_channels_24(dest_format->channels,
+ src_format->channels,
+ buf, len, &len);
+ if (!buf)
+ g_error("pcm_convert_channels_24() failed");
+ }
+
+ if (src_format->sample_rate == dest_format->sample_rate) {
+ assert(dest_size >= len);
+ memcpy(dest_buffer, buf, len);
+ } else {
+ len = pcm_resample_24(dest_format->channels,
+ src_format->sample_rate, buf, len,
+ dest_format->sample_rate,
+ (int32_t*)dest_buffer, dest_size,
+ &state->resample);
+ }
+
+ return len;
+}
+
+/* outFormat bits must be 16 and channels must be 1 or 2! */
+size_t pcm_convert(const struct audio_format *inFormat,
+ const char *src, size_t src_size,
+ const struct audio_format *outFormat,
+ char *outBuffer,
+ struct pcm_convert_state *convState)
+{
+ switch (outFormat->bits) {
+ case 16:
+ return pcm_convert_16(inFormat, src, src_size,
+ outFormat, (int16_t*)outBuffer,
+ convState);
+ case 24:
+ return pcm_convert_24(inFormat, src, src_size,
+ outFormat, (int32_t*)outBuffer,
+ convState);
+
+ default:
+ g_error("cannot convert to %u bit\n", outFormat->bits);
+ }
+}
+
+size_t pcm_convert_size(const struct audio_format *inFormat, size_t src_size,
+ const struct audio_format *outFormat)
+{
+ const double ratio = (double)outFormat->sample_rate /
+ (double)inFormat->sample_rate;
+ size_t dest_size = src_size;
+
+ /* no partial frames allowed */
+ assert((src_size % audio_format_frame_size(inFormat)) == 0);
+
+ dest_size /= audio_format_frame_size(inFormat);
+ dest_size = ceil((double)dest_size * ratio);
+ dest_size *= audio_format_frame_size(outFormat);
+
+ return dest_size;
+}