initial import

src/plugin_common/Makefile.am

@@ -0,0 +1,27 @@
+## Process this file with automake to produce Makefile.in
+
+AUTOMAKE_OPTIONS = foreign
+
+INCLUDES = -I$(top_srcdir)/include
+
+noinst_LIBRARIES = libplugin-common.a
+
+noinst_HEADERS = \
+	all.h \
+	canonical_tag.h \
+	dither.h
+
+libplugin_common_a_SOURCES = \
+	canonical_tag.c \
+	dither.c
+
+EXTRA_DIST = \
+	Makefile.lite \
+	Makefile.vc \
+	README
+
+debug:
+	$(MAKE) all CFLAGS="@DEBUG@"
+
+profile:
+	$(MAKE) all CFLAGS="@PROFILE@"

src/plugin_common/Makefile.lite

@@ -0,0 +1,14 @@
+#
+# GNU makefile
+#
+
+LIB_NAME = libplugin-common
+INCLUDES = -I../../include
+
+OBJS = \
+	canonical_tag.o \
+	dither.o
+
+include ../../build/lib.mk
+
+# DO NOT DELETE THIS LINE -- make depend depends on it.

src/plugin_common/Makefile.vc

@@ -0,0 +1,24 @@
+!include <win32.mak>
+
+!IFDEF DEBUG
+.c.obj:
+	$(cc) /D "_LIB" /GX $(cdebug) $(cflags) /I "..\..\include" -DSTRICT -YX /Od /D "_DEBUG" $<
+!else
+.c.obj:
+	$(cc) /D "_LIB" /O2 $(crelease) $(cflags) /I "..\..\include" -DSTRICT -YX -DNODEBUG $<
+!endif
+
+C_FILES= \
+	canonical_tag.c \
+	dither.c
+
+OBJS= $(C_FILES:.c=.obj)
+
+all: plugin-common.lib
+
+plugin-common.lib: $(OBJS)
+	link.exe -lib /nodefaultlib -out:../../obj/lib/$*.lib $(OBJS)
+
+clean:
+	-del *.obj *.pch
+	-del ..\..\obj\lib\plugin-common.lib ..\..\obj\lib\plugin-common.pdb

src/plugin_common/README

@@ -0,0 +1,2 @@
+This directory contains a convenience library of routines that are
+common to the plugins.

src/plugin_common/all.h

@@ -0,0 +1,29 @@
+/* plugin_common - Routines common to several plugins
+ * Copyright (C) 2002  Josh Coalson
+ *
+ * dithering routine derived from (other GPLed source):
+ * mad - MPEG audio decoder
+ * Copyright (C) 2000-2001 Robert Leslie
+ *
+ * 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.
+ */
+
+#ifndef FLAC__PLUGIN_COMMON__ALL_H
+#define FLAC__PLUGIN_COMMON__ALL_H
+
+#include "canonical_tag.h"
+#include "dither.h"
+
+#endif

src/plugin_common/canonical_tag.c

@@ -0,0 +1,24 @@
+/* plugin_common - Routines common to several plugins
+ * Copyright (C) 2002  Josh Coalson
+ *
+ * dithering routine derived from (other GPLed source):
+ * mad - MPEG audio decoder
+ * Copyright (C) 2000-2001 Robert Leslie
+ *
+ * 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 "canonical_tag.h"
+#include "FLAC/assert.h"

src/plugin_common/canonical_tag.h

@@ -0,0 +1,26 @@
+/* plugin_common - Routines common to several plugins
+ * Copyright (C) 2002  Josh Coalson
+ *
+ * dithering routine derived from (other GPLed source):
+ * mad - MPEG audio decoder
+ * Copyright (C) 2000-2001 Robert Leslie
+ *
+ * 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.
+ */
+
+#ifndef FLAC__PLUGIN_COMMON__CANONICAL_TAG_H
+#define FLAC__PLUGIN_COMMON__CANONICAL_TAG_H
+
+#endif

src/plugin_common/dither.c

@@ -0,0 +1,168 @@
+/* plugin_common - Routines common to several plugins
+ * Copyright (C) 2002  Josh Coalson
+ *
+ * dithering routine derived from (other GPLed source):
+ * mad - MPEG audio decoder
+ * Copyright (C) 2000-2001 Robert Leslie
+ *
+ * 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 "dither.h"
+#include "FLAC/assert.h"
+
+#ifdef max
+#undef max
+#endif
+#define max(a,b) ((a)>(b)?(a):(b))
+
+
+#define FLAC__DO_DITHER
+
+#define MAX_SUPPORTED_CHANNELS 2
+
+#if defined _MSC_VER || defined __MINGW32__
+#define FLAC__INLINE __inline
+#else
+#define FLAC__INLINE
+#endif
+
+/* 32-bit pseudo-random number generator */
+static FLAC__INLINE FLAC__uint32 prng(FLAC__uint32 state)
+{
+	return (state * 0x0019660dL + 0x3c6ef35fL) & 0xffffffffL;
+}
+
+/* dither routine derived from MAD winamp plugin */
+
+typedef struct {
+	FLAC__int32 error[3];
+	FLAC__int32 random;
+} dither_state;
+
+static FLAC__INLINE FLAC__int32 linear_dither(unsigned source_bps, unsigned target_bps, FLAC__int32 sample, dither_state *dither, const FLAC__int32 MIN, const FLAC__int32 MAX)
+{
+	unsigned scalebits;
+	FLAC__int32 output, mask, random;
+
+	FLAC__ASSERT(source_bps < 32);
+	FLAC__ASSERT(target_bps <= 24);
+	FLAC__ASSERT(target_bps <= source_bps);
+
+	/* noise shape */
+	sample += dither->error[0] - dither->error[1] + dither->error[2];
+
+	dither->error[2] = dither->error[1];
+	dither->error[1] = dither->error[0] / 2;
+
+	/* bias */
+	output = sample + (1L << (source_bps - target_bps - 1));
+
+	scalebits = source_bps - target_bps;
+	mask = (1L << scalebits) - 1;
+
+	/* dither */
+	random = (FLAC__int32)prng(dither->random);
+	output += (random & mask) - (dither->random & mask);
+
+	dither->random = random;
+
+	/* clip */
+	if(output > MAX) {
+		output = MAX;
+
+		if(sample > MAX)
+			sample = MAX;
+	}
+	else if(output < MIN) {
+		output = MIN;
+
+		if(sample < MIN)
+			sample = MIN;
+	}
+
+	/* quantize */
+	output &= ~mask;
+
+	/* error feedback */
+	dither->error[0] = sample - output;
+
+	/* scale */
+	return output >> scalebits;
+}
+
+unsigned FLAC__plugin_common__pack_pcm(FLAC__byte *data, FLAC__int32 *input, unsigned wide_samples, unsigned channels, unsigned source_bps, unsigned target_bps)
+{
+	static dither_state dither[MAX_SUPPORTED_CHANNELS];
+	FLAC__byte * const start = data;
+	FLAC__int32 sample;
+	unsigned samples = wide_samples * channels;
+	const unsigned bytes_per_sample = target_bps / 8;
+
+	FLAC__ASSERT(MAX_SUPPORTED_CHANNELS == 2);
+	FLAC__ASSERT(channels > 0 && channels <= MAX_SUPPORTED_CHANNELS);
+	FLAC__ASSERT(source_bps < 32);
+	FLAC__ASSERT(target_bps <= 24);
+	FLAC__ASSERT(target_bps <= source_bps);
+	FLAC__ASSERT((source_bps & 7) == 0);
+	FLAC__ASSERT((target_bps & 7) == 0);
+
+	if(source_bps != target_bps) {
+		const FLAC__int32 MIN = -(1L << source_bps);
+		const FLAC__int32 MAX = ~MIN; /*(1L << (source_bps-1)) - 1 */
+		const unsigned dither_twiggle = channels - 1;
+		unsigned dither_source = 0;
+
+		while(samples--) {
+			sample = linear_dither(source_bps, target_bps, *input++, &dither[dither_source], MIN, MAX);
+			dither_source ^= dither_twiggle;
+
+			switch(target_bps) {
+				case 8:
+					data[0] = sample ^ 0x80;
+					break;
+				case 24:
+					data[2] = (FLAC__byte)(sample >> 16);
+					/* fall through */
+				case 16:
+					data[1] = (FLAC__byte)(sample >> 8);
+					data[0] = (FLAC__byte)sample;
+			}
+
+			data += bytes_per_sample;
+		}
+	}
+	else {
+		while(samples--) {
+			sample = *input++;
+
+			switch(target_bps) {
+				case 8:
+					data[0] = sample ^ 0x80;
+					break;
+				case 24:
+					data[2] = (FLAC__byte)(sample >> 16);
+					/* fall through */
+				case 16:
+					data[1] = (FLAC__byte)(sample >> 8);
+					data[0] = (FLAC__byte)sample;
+			}
+
+			data += bytes_per_sample;
+		}
+	}
+
+	return data - start;
+}

src/plugin_common/dither.h

@@ -0,0 +1,30 @@
+/* plugin_common - Routines common to several plugins
+ * Copyright (C) 2002  Josh Coalson
+ *
+ * dithering routine derived from (other GPLed source):
+ * mad - MPEG audio decoder
+ * Copyright (C) 2000-2001 Robert Leslie
+ *
+ * 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.
+ */
+
+#ifndef FLAC__PLUGIN_COMMON__DITHER_H
+#define FLAC__PLUGIN_COMMON__DITHER_H
+
+#include "FLAC/ordinals.h"
+
+unsigned FLAC__plugin_common__pack_pcm(FLAC__byte *data, FLAC__int32 *input, unsigned wide_samples, unsigned channels, unsigned source_bps, unsigned target_bps);
+
+#endif