pcm_byteswap: move code to libutil

3 files changed, 199 insertions, 38 deletions

diff --git a/src/pcm_byteswap.c b/src/pcm_byteswap.c
index d56c3a87..0a7e2fbb 100644
--- a/src/pcm_byteswap.c
+++ b/src/pcm_byteswap.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2003-2011 The Music Player Daemon Project
+ * Copyright (C) 2003-2012 The Music Player Daemon Project
  * http://www.musicpd.org
  *
  * This program is free software; you can redistribute it and/or modify
@@ -20,14 +20,10 @@
 #include "config.h"
 #include "pcm_byteswap.h"
 #include "pcm_buffer.h"
-
-#include <glib.h>
+#include "util/byte_reverse.h"
 
 #include <assert.h>
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "pcm"
-
 const int16_t *pcm_byteswap_16(struct pcm_buffer *buffer,
 			       const int16_t *src, size_t len)
 {
@@ -35,13 +31,10 @@ const int16_t *pcm_byteswap_16(struct pcm_buffer *buffer,
 
 	assert(buf != NULL);
 
-	const int16_t *src_end = src + len / sizeof(*src);
-	int16_t *dest = buf;
-	while (src < src_end) {
-		const int16_t x = *src++;
-		*dest++ = GUINT16_SWAP_LE_BE(x);
-	}
+	const uint8_t *src8 = (const uint8_t *)src;
+	const void *src_end = src8 + len;
 
+	reverse_bytes_16((uint16_t *)buf, (const uint16_t *)src, src_end);
 	return buf;
 }
 
@@ -52,41 +45,31 @@ const int32_t *pcm_byteswap_32(struct pcm_buffer *buffer,
 
 	assert(buf != NULL);
 
-	const int32_t *src_end = src + len / sizeof(*src);
-	int32_t *dest = buf;
-	while (src < src_end) {
-		const int32_t x = *src++;
-		*dest++ = GUINT32_SWAP_LE_BE(x);
-	}
+	const uint8_t *src8 = (const uint8_t *)src;
+	const void *src_end = src8 + len;
 
+	reverse_bytes_32((uint32_t *)buf, (const uint32_t *)src, src_end);
 	return buf;
 }
 
 const void *
 pcm_byteswap(struct pcm_buffer *buffer, enum sample_format format,
-	     const void *src, size_t size)
+	     const void *_src, size_t size)
 {
-	switch (format) {
-	case SAMPLE_FORMAT_UNDEFINED:
-	case SAMPLE_FORMAT_S24:
-	case SAMPLE_FORMAT_FLOAT:
-	case SAMPLE_FORMAT_DSD_OVER_USB:
-		/* not implemented */
-		return NULL;
-
-	case SAMPLE_FORMAT_S8:
-	case SAMPLE_FORMAT_DSD:
+	const uint8_t *const src = _src;
+
+	if (size <= 1)
+		return src;
+
+	size_t sample_size = sample_format_size(format);
+	if (sample_size <= 1)
 		return src;
 
-	case SAMPLE_FORMAT_S16:
-		return pcm_byteswap_16(buffer, src, size);
+	assert(size % sample_size == 0);
 
-	case SAMPLE_FORMAT_S24_P32:
-	case SAMPLE_FORMAT_S32:
-		return pcm_byteswap_32(buffer, src, size);
-	}
+	uint8_t *dest = pcm_buffer_get(buffer, size);
+	assert(dest != NULL);
 
-	/* unreachable */
-	assert(false);
-	return NULL;
+	reverse_bytes(dest, src, src + size, sample_size);
+	return dest;
 }
diff --git a/src/util/byte_reverse.c b/src/util/byte_reverse.c
new file mode 100644
index 00000000..e96af14b
--- /dev/null
+++ b/src/util/byte_reverse.c
@@ -0,0 +1,123 @@
+/*
+ * Copyright (C) 2003-2012 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 "byte_reverse.h"
+
+#include <glib.h>
+#include <assert.h>
+
+void
+reverse_bytes_16(uint16_t *dest, const uint16_t *src, const uint16_t *src_end)
+{
+	assert(dest != NULL);
+	assert(src != NULL);
+	assert(src_end >= src);
+
+	while (src < src_end) {
+		const uint16_t x = *src++;
+		*dest++ = GUINT16_SWAP_LE_BE(x);
+	}
+}
+
+void
+reverse_bytes_32(uint32_t *dest, const uint32_t *src, const uint32_t *src_end)
+{
+	assert(dest != NULL);
+	assert(src != NULL);
+	assert(src_end >= src);
+
+	while (src < src_end) {
+		const uint32_t x = *src++;
+		*dest++ = GUINT32_SWAP_LE_BE(x);
+	}
+}
+
+void
+reverse_bytes_64(uint64_t *dest, const uint64_t *src, const uint64_t *src_end)
+{
+	assert(dest != NULL);
+	assert(src != NULL);
+	assert(src_end >= src);
+
+	while (src < src_end) {
+		const uint64_t x = *src++;
+		*dest++ = GUINT64_SWAP_LE_BE(x);
+	}
+}
+
+static void
+reverse_bytes_linear(uint8_t *dest, const uint8_t *src, size_t n)
+{
+	src += n;
+
+	while (n-- > 0)
+		*dest++ = *--src;
+}
+
+static void
+reverse_bytes_generic(uint8_t *dest,
+		      const uint8_t *src, const uint8_t *src_end,
+		      size_t frame_size)
+{
+	assert(dest != NULL);
+	assert(src != NULL);
+	assert(src_end >= src);
+	assert(frame_size > 0);
+	assert((src_end - src) % frame_size == 0);
+
+	while (src < src_end) {
+		reverse_bytes_linear(dest, src, frame_size);
+		dest += frame_size;
+		src += frame_size;
+	}
+}
+
+void
+reverse_bytes(uint8_t *dest, const uint8_t *src, const uint8_t *src_end,
+	      size_t frame_size)
+{
+	assert(dest != NULL);
+	assert(src != NULL);
+	assert(src_end >= src);
+	assert(frame_size > 0);
+	assert((src_end - src) % frame_size == 0);
+
+	switch (frame_size) {
+	case 2:
+		reverse_bytes_16((uint16_t *)dest,
+				 (const uint16_t *)src,
+				 (const uint16_t *)src_end);
+		break;
+
+	case 4:
+		reverse_bytes_32((uint32_t *)dest,
+				 (const uint32_t *)src,
+				 (const uint32_t *)src_end);
+		break;
+
+	case 8:
+		reverse_bytes_64((uint64_t *)dest,
+				 (const uint64_t *)src,
+				 (const uint64_t *)src_end);
+		break;
+
+	default:
+		reverse_bytes_generic(dest, src, src_end, frame_size);
+	}
+}
diff --git a/src/util/byte_reverse.h b/src/util/byte_reverse.h
new file mode 100644
index 00000000..63213d6c
--- /dev/null
+++ b/src/util/byte_reverse.h
@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2003-2012 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.
+ */
+
+#ifndef MPD_BYTE_REVERSE_H
+#define MPD_BYTE_REVERSE_H
+
+#include <stdint.h>
+#include <stddef.h>
+
+/**
+ * Reverse the bytes in each 16 bit "frame".  This function can be
+ * used for in-place operation.
+ */
+void
+reverse_bytes_16(uint16_t *dest, const uint16_t *src, const uint16_t *src_end);
+
+/**
+ * Reverse the bytes in each 32 bit "frame".  This function can be
+ * used for in-place operation.
+ */
+void
+reverse_bytes_32(uint32_t *dest, const uint32_t *src, const uint32_t *src_end);
+
+/**
+ * Reverse the bytes in each 64 bit "frame".  This function can be
+ * used for in-place operation.
+ */
+void
+reverse_bytes_64(uint64_t *dest, const uint64_t *src, const uint64_t *src_end);
+
+/**
+ * Reverse the bytes in each "frame".  This function cannot be used
+ * for in-place operation.
+ */
+void
+reverse_bytes(uint8_t *dest, const uint8_t *src, const uint8_t *src_end,
+	      size_t frame_size);
+
+#endif