pcm_utils: moved conversion code to pcm_convert.c

All what's left in pcm_utils.h is the pcm_range() utility function,
which is only used internally by pcm_volume and pcm_mix.

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;
+}