From 85225bb1292d1885e0261fb5109d18ecd584c267 Mon Sep 17 00:00:00 2001
From: Andre Noll <maan@systemlinux.org>
Date: Fri, 30 Mar 2007 17:14:04 +0200
Subject: [PATCH 1/1] fix compress filter for big endian machines

This was broken since day one as it depended on little-endianness. Fix
it by checking the byte sex in configure and let the decoders
produce host endian 16 bit audio output by using the new
write_int16_host_endian() inline function in filter.h

This allows to omit the ugly byte-swapping in osx_write we've had
before.
---
 aacdec.c     |  4 ++--
 configure.ac |  2 ++
 filter.h     | 16 ++++++++++++++++
 mp3dec.c     |  9 ++++-----
 oggdec.c     |  4 ++++
 osx_write.c  |  8 +-------
 6 files changed, 29 insertions(+), 14 deletions(-)

diff --git a/aacdec.c b/aacdec.c
index 9ed12012..c860a3b7 100644
--- a/aacdec.c
+++ b/aacdec.c
@@ -154,8 +154,8 @@ static ssize_t aacdec(char *input_buffer, size_t len, struct filter_node *fn)
 		goto out;
 	for (i = 0; i < padd->frame_info.samples; i++) {
 		short *s = (short *)outbuffer;
-		fn->buf[fn->loaded++] = s[i] & 0xff;
-		fn->buf[fn->loaded++] = (s[i] >> 8) & 0xff;
+		write_int16_host_endian(fn->buf + fn->loaded, s);
+		fn->loaded += 2;
 	}
 success:
 	ret = consumed;
diff --git a/configure.ac b/configure.ac
index aeb6f8d4..316f95c7 100644
--- a/configure.ac
+++ b/configure.ac
@@ -15,6 +15,8 @@ AC_MSG_CHECKING(os type)
 OSTYPE="`$UNAMEPATH -s`"
 AC_MSG_RESULT("$OSTYPE")
 
+AC_C_BIGENDIAN()
+
 AC_PROG_CC
 AC_PROG_CPP
 AC_PROG_INSTALL
diff --git a/filter.h b/filter.h
index 321d763c..06d727f5 100644
--- a/filter.h
+++ b/filter.h
@@ -299,6 +299,20 @@ void (*print_help)(void);
  */
 void *(*parse_config)(int argc, char **argv);
 };
+
+
+static inline void write_int16_host_endian(char *buf, int16_t val)
+{
+#ifndef BIGENDIAN
+	*buf = val >> 8;
+	*(buf + 1) = val & 0xff;
+#else
+	*buf = val & 0xff;
+	*(buf + 1) = val >> 8;
+#endif
+}
+
+
 /** \cond */
 extern struct filter filters[];
 #define DECLARE_EXTERN_FILTER_INIT(name) \
@@ -348,3 +362,5 @@ DECLARE_EXTERN_FILTER_INIT(oggdec);
 	AACDEC_FILTER \
 	OGGDEC_FILTER \
 	{ .name = NULL } };
+
+
diff --git a/mp3dec.c b/mp3dec.c
index 401a03c5..a1374b73 100644
--- a/mp3dec.c
+++ b/mp3dec.c
@@ -74,14 +74,13 @@ next_frame:
 	mad_synth_frame(&pmd->synth, &pmd->frame);
 
 	for (i = 0; i < pmd->synth.pcm.length; i++) {
-		/* output format: unsigned 16 bit little endian */
 		signed short s = MAD_TO_SHORT(pmd->synth.pcm.samples[0][i]);
-		fn->buf[fn->loaded++] = s & 0xff;
-		fn->buf[fn->loaded++] = s >> 8;
+		write_int16_host_endian(fn->buf + fn->loaded, s);
+		fn->loaded += 2;
 		if (MAD_NCHANNELS(&pmd->frame.header) == 2) { /* stereo */
 			s = MAD_TO_SHORT(pmd->synth.pcm.samples[1][i]);
-			fn->buf[fn->loaded++] = s & 0xff;
-			fn->buf[fn->loaded++] = s >> 8;
+			write_int16_host_endian(fn->buf + fn->loaded, s);
+			fn->loaded += 2;
 		}
 		if (fn->loaded != fn->bufsize) /* output buffer not full */
 			continue;
diff --git a/oggdec.c b/oggdec.c
index 929e2ecc..2ec13d8d 100644
--- a/oggdec.c
+++ b/oggdec.c
@@ -31,7 +31,11 @@
 
 /** \cond some internal constants */
 #define BITS 16
+#ifdef BIGENDIAN
 #define ENDIAN 0
+#else
+#define ENDIAN 1
+#endif
 #define SIGN 1
 /** \endcond */
 
diff --git a/osx_write.c b/osx_write.c
index 107746c7..f13ec6e1 100644
--- a/osx_write.c
+++ b/osx_write.c
@@ -111,14 +111,8 @@ static void fill_buffer(struct osx_buffer *b, short *source, long size)
 		b->size = size;
 	}
 	dest = b->buffer;
-	while (size--) {
-		char *tmp = (char *)source;
-		char c = *tmp;
-		*tmp = *(tmp + 1);
-		*(tmp + 1) = c;
-		/* *dest++ = ((*source++) + 32768) / 65536.0; */
+	while (size--)
 		*dest++ = (*source++) / 32768.0;
-	}
 	b->ptr = b->buffer;
 	b->remaining = b->size;
 }
-- 
2.39.2