1 files changed, 77 insertions, 0 deletions
diff --git a/src/pcm/pcm_pack.c b/src/pcm/pcm_pack.c
new file mode 100644
index 000000000..921d880c0
--- /dev/null
+++ b/src/pcm/pcm_pack.c
@@ -0,0 +1,77 @@
+/*
+ * 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 "pcm_pack.h"
+
+#include <glib.h>
+
+static void
+pack_sample(uint8_t *dest, const int32_t *src0)
+{
+	const uint8_t *src = (const uint8_t *)src0;
+
+	if (G_BYTE_ORDER == G_BIG_ENDIAN)
+		++src;
+
+	*dest++ = *src++;
+	*dest++ = *src++;
+	*dest++ = *src++;
+}
+
+void
+pcm_pack_24(uint8_t *dest, const int32_t *src, const int32_t *src_end)
+{
+	/* duplicate loop to help the compiler's optimizer (constant
+	   parameter to the pack_sample() inline function) */
+
+	while (src < src_end) {
+		pack_sample(dest, src++);
+		dest += 3;
+	}
+}
+
+static void
+unpack_sample(int32_t *dest0, const uint8_t *src)
+{
+	uint8_t *dest = (uint8_t *)dest0;
+
+	if (G_BYTE_ORDER == G_BIG_ENDIAN)
+		/* extend the sign bit to the most fourth byte */
+		*dest++ = *src & 0x80 ? 0xff : 0x00;
+
+	*dest++ = *src++;
+	*dest++ = *src++;
+	*dest++ = *src;
+
+	if (G_BYTE_ORDER == G_LITTLE_ENDIAN)
+		/* extend the sign bit to the most fourth byte */
+		*dest++ = *src & 0x80 ? 0xff : 0x00;
+}
+
+void
+pcm_unpack_24(int32_t *dest, const uint8_t *src, const uint8_t *src_end)
+{
+	/* duplicate loop to help the compiler's optimizer (constant
+	   parameter to the unpack_sample() inline function) */
+
+	while (src < src_end) {
+		unpack_sample(dest++, src);
+		src += 3;
+	}
+}