initial import

6 files changed, 588 insertions, 0 deletions

diff --git a/src/plugin_common/defs.h b/src/plugin_common/defs.h
new file mode 100644
index 00000000..2ef5b9ad
--- /dev/null
+++ b/src/plugin_common/defs.h
@@ -0,0 +1,26 @@
+/* plugin_common - Routines common to several plugins
+ * Copyright (C) 2002  Josh Coalson
+ *
+ * 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__DEFS_H
+#define FLAC__PLUGIN_COMMON__DEFS_H
+
+#include "export.h"
+
+#define FLAC_PLUGIN__MAX_SUPPORTED_CHANNELS 2
+
+#endif
diff --git a/src/plugin_common/include/Makefile.am b/src/plugin_common/include/Makefile.am
new file mode 100644
index 00000000..71693e5c
--- /dev/null
+++ b/src/plugin_common/include/Makefile.am
@@ -0,0 +1,18 @@
+#  plugin_common - Routines common to several plugins
+#  Copyright (C) 2002  Josh Coalson
+# 
+#  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.
+
+SUBDIRS = private
diff --git a/src/plugin_common/include/private/Makefile.am b/src/plugin_common/include/private/Makefile.am
new file mode 100644
index 00000000..74389f4e
--- /dev/null
+++ b/src/plugin_common/include/private/Makefile.am
@@ -0,0 +1,19 @@
+#  plugin_common - Routines common to several plugins
+#  Copyright (C) 2002  Josh Coalson
+# 
+#  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.
+
+noinst_HEADERS = \
+	fast_float_math_hack.h
diff --git a/src/plugin_common/include/private/fast_float_math_hack.h b/src/plugin_common/include/private/fast_float_math_hack.h
new file mode 100644
index 00000000..d8608fc4
--- /dev/null
+++ b/src/plugin_common/include/private/fast_float_math_hack.h
@@ -0,0 +1,39 @@
+#   ifdef __ICL /* only Intel C compiler has fmath ??? */
+
+    #include <mathf.h>
+
+/* Nearest integer, absolute value, etc. */
+
+    #define ceil ceilf
+    #define fabs fabsf
+    #define floor floorf
+    #define fmod fmodf
+    #define rint rintf
+    #define hypot hypotf
+
+/* Power functions */
+
+    #define pow powf
+    #define sqrt sqrtf
+
+/* Exponential and logarithmic functions */
+
+    #define exp expf
+    #define log logf
+    #define log10 log10f
+
+/* Trigonometric functions */
+
+    #define acos acosf
+    #define asin asinf
+    #define atan atanf
+    #define cos cosf
+    #define sin sinf
+    #define tan tanf
+
+/* Hyperbolic functions */
+    #define cosh coshf
+    #define sinh sinhf
+    #define tanh tanhf
+
+#   endif
diff --git a/src/plugin_common/replaygain_synthesis.c b/src/plugin_common/replaygain_synthesis.c
new file mode 100644
index 00000000..dd1951e0
--- /dev/null
+++ b/src/plugin_common/replaygain_synthesis.c
@@ -0,0 +1,437 @@
+/* plugin_common - Routines common to several plugins
+ * Copyright (C) 2002  Josh Coalson
+ *
+ * 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.
+ */
+/*
+ * This is an aggregation of pieces of code from John Edwards' WaveGain
+ * program.  Mostly cosmetic changes were made; otherwise, the dithering
+ * code is almost untouched and the gain processing was converted from
+ * processing a whole file to processing chunks of samples.
+ *
+ * The original copyright notices for WaveGain's dither.c and wavegain.c
+ * appear below:
+ */
+/*
+ * (c) 2002 John Edwards
+ * mostly lifted from work by Frank Klemm
+ * random functions for dithering.
+ */
+/*
+ * Copyright (C) 2002 John Edwards
+ * Additional code by Magnus Holmgren and Gian-Carlo Pascutto
+ */
+
+#include <string.h> /* for memset() */
+#include <math.h>
+#include "private/fast_float_math_hack.h"
+#include "replaygain_synthesis.h"
+#include "FLAC/assert.h"
+
+#if defined _MSC_VER
+#define FLAC__INLINE __inline
+#else
+#define FLAC__INLINE
+#endif
+
+
+/*
+ * the following is based on parts of dither.c
+ */
+
+
+/*
+ *  This is a simple random number generator with good quality for audio purposes.
+ *  It consists of two polycounters with opposite rotation direction and different
+ *  periods. The periods are coprime, so the total period is the product of both.
+ *
+ *     -------------------------------------------------------------------------------------------------
+ * +-> |31:30:29:28:27:26:25:24:23:22:21:20:19:18:17:16:15:14:13:12:11:10: 9: 8: 7: 6: 5: 4: 3: 2: 1: 0|
+ * |   -------------------------------------------------------------------------------------------------
+ * |                                                                          |  |  |  |     |        |
+ * |                                                                          +--+--+--+-XOR-+--------+
+ * |                                                                                      |
+ * +--------------------------------------------------------------------------------------+
+ *
+ *     -------------------------------------------------------------------------------------------------
+ *     |31:30:29:28:27:26:25:24:23:22:21:20:19:18:17:16:15:14:13:12:11:10: 9: 8: 7: 6: 5: 4: 3: 2: 1: 0| <-+
+ *     -------------------------------------------------------------------------------------------------   |
+ *       |  |           |  |                                                                               |
+ *       +--+----XOR----+--+                                                                               |
+ *                |                                                                                        |
+ *                +----------------------------------------------------------------------------------------+
+ *
+ *
+ *  The first has an period of 3*5*17*257*65537, the second of 7*47*73*178481,
+ *  which gives a period of 18.410.713.077.675.721.215. The result is the
+ *  XORed values of both generators.
+ */
+
+static unsigned int random_int_()
+{
+	static const unsigned char parity_[256] = {
+		0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,
+		1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,
+		1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,
+		0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,
+		1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,
+		0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,
+		0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,
+		1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0
+	};
+	static unsigned int r1_ = 1;
+	static unsigned int r2_ = 1;
+
+	unsigned int t1, t2, t3, t4;
+
+	/* Parity calculation is done via table lookup, this is also available
+	 * on CPUs without parity, can be implemented in C and avoid unpredictable
+	 * jumps and slow rotate through the carry flag operations.
+	 */
+	t3   = t1 = r1_;    t4   = t2 = r2_;
+	t1  &= 0xF5;        t2 >>= 25;
+	t1   = parity_[t1]; t2  &= 0x63;
+	t1 <<= 31;          t2   = parity_[t2];
+
+	return (r1_ = (t3 >> 1) | t1 ) ^ (r2_ = (t4 + t4) | t2 );
+}
+
+/* gives a equal distributed random number */
+/* between -2^31*mult and +2^31*mult */
+static double random_equi_(double mult)
+{
+	return mult * (int) random_int_();
+}
+
+/* gives a triangular distributed random number */
+/* between -2^32*mult and +2^32*mult */
+static double random_triangular_(double mult)
+{
+	return mult * ( (double) (int) random_int_() + (double) (int) random_int_() );
+}
+
+
+static const float  F44_0 [16 + 32] = {
+	(float)0, (float)0, (float)0, (float)0, (float)0, (float)0, (float)0, (float)0,
+	(float)0, (float)0, (float)0, (float)0, (float)0, (float)0, (float)0, (float)0,
+
+	(float)0, (float)0, (float)0, (float)0, (float)0, (float)0, (float)0, (float)0,
+	(float)0, (float)0, (float)0, (float)0, (float)0, (float)0, (float)0, (float)0,
+
+	(float)0, (float)0, (float)0, (float)0, (float)0, (float)0, (float)0, (float)0,
+	(float)0, (float)0, (float)0, (float)0, (float)0, (float)0, (float)0, (float)0
+};
+
+
+static const float  F44_1 [16 + 32] = {  /* SNR(w) = 4.843163 dB, SNR = -3.192134 dB */
+	(float) 0.85018292704024355931, (float) 0.29089597350995344721, (float)-0.05021866022121039450, (float)-0.23545456294599161833,
+	(float)-0.58362726442227032096, (float)-0.67038978965193036429, (float)-0.38566861572833459221, (float)-0.15218663390367969967,
+	(float)-0.02577543084864530676, (float) 0.14119295297688728127, (float) 0.22398848581628781612, (float) 0.15401727203382084116,
+	(float) 0.05216161232906000929, (float)-0.00282237820999675451, (float)-0.03042794608323867363, (float)-0.03109780942998826024,
+
+	(float) 0.85018292704024355931, (float) 0.29089597350995344721, (float)-0.05021866022121039450, (float)-0.23545456294599161833,
+	(float)-0.58362726442227032096, (float)-0.67038978965193036429, (float)-0.38566861572833459221, (float)-0.15218663390367969967,
+	(float)-0.02577543084864530676, (float) 0.14119295297688728127, (float) 0.22398848581628781612, (float) 0.15401727203382084116,
+	(float) 0.05216161232906000929, (float)-0.00282237820999675451, (float)-0.03042794608323867363, (float)-0.03109780942998826024,
+
+	(float) 0.85018292704024355931, (float) 0.29089597350995344721, (float)-0.05021866022121039450, (float)-0.23545456294599161833,
+	(float)-0.58362726442227032096, (float)-0.67038978965193036429, (float)-0.38566861572833459221, (float)-0.15218663390367969967,
+	(float)-0.02577543084864530676, (float) 0.14119295297688728127, (float) 0.22398848581628781612, (float) 0.15401727203382084116,
+	(float) 0.05216161232906000929, (float)-0.00282237820999675451, (float)-0.03042794608323867363, (float)-0.03109780942998826024,
+};
+
+
+static const float  F44_2 [16 + 32] = {  /* SNR(w) = 10.060213 dB, SNR = -12.766730 dB */
+	(float) 1.78827593892108555290, (float) 0.95508210637394326553, (float)-0.18447626783899924429, (float)-0.44198126506275016437,
+	(float)-0.88404052492547413497, (float)-1.42218907262407452967, (float)-1.02037566838362314995, (float)-0.34861755756425577264,
+	(float)-0.11490230170431934434, (float) 0.12498899339968611803, (float) 0.38065885268563131927, (float) 0.31883491321310506562,
+	(float) 0.10486838686563442765, (float)-0.03105361685110374845, (float)-0.06450524884075370758, (float)-0.02939198261121969816,
+
+	(float) 1.78827593892108555290, (float) 0.95508210637394326553, (float)-0.18447626783899924429, (float)-0.44198126506275016437,
+	(float)-0.88404052492547413497, (float)-1.42218907262407452967, (float)-1.02037566838362314995, (float)-0.34861755756425577264,
+	(float)-0.11490230170431934434, (float) 0.12498899339968611803, (float) 0.38065885268563131927, (float) 0.31883491321310506562,
+	(float) 0.10486838686563442765, (float)-0.03105361685110374845, (float)-0.06450524884075370758, (float)-0.02939198261121969816,
+
+	(float) 1.78827593892108555290, (float) 0.95508210637394326553, (float)-0.18447626783899924429, (float)-0.44198126506275016437,
+	(float)-0.88404052492547413497, (float)-1.42218907262407452967, (float)-1.02037566838362314995, (float)-0.34861755756425577264,
+	(float)-0.11490230170431934434, (float) 0.12498899339968611803, (float) 0.38065885268563131927, (float) 0.31883491321310506562,
+	(float) 0.10486838686563442765, (float)-0.03105361685110374845, (float)-0.06450524884075370758, (float)-0.02939198261121969816,
+};
+
+
+static const float  F44_3 [16 + 32] = {  /* SNR(w) = 15.382598 dB, SNR = -29.402334 dB */
+	(float) 2.89072132015058161445, (float) 2.68932810943698754106, (float) 0.21083359339410251227, (float)-0.98385073324997617515,
+	(float)-1.11047823227097316719, (float)-2.18954076314139673147, (float)-2.36498032881953056225, (float)-0.95484132880101140785,
+	(float)-0.23924057925542965158, (float)-0.13865235703915925642, (float) 0.43587843191057992846, (float) 0.65903257226026665927,
+	(float) 0.24361815372443152787, (float)-0.00235974960154720097, (float) 0.01844166574603346289, (float) 0.01722945988740875099,
+
+	(float) 2.89072132015058161445, (float) 2.68932810943698754106, (float) 0.21083359339410251227, (float)-0.98385073324997617515,
+	(float)-1.11047823227097316719, (float)-2.18954076314139673147, (float)-2.36498032881953056225, (float)-0.95484132880101140785,
+	(float)-0.23924057925542965158, (float)-0.13865235703915925642, (float) 0.43587843191057992846, (float) 0.65903257226026665927,
+	(float) 0.24361815372443152787, (float)-0.00235974960154720097, (float) 0.01844166574603346289, (float) 0.01722945988740875099,
+
+	(float) 2.89072132015058161445, (float) 2.68932810943698754106, (float) 0.21083359339410251227, (float)-0.98385073324997617515,
+	(float)-1.11047823227097316719, (float)-2.18954076314139673147, (float)-2.36498032881953056225, (float)-0.95484132880101140785,
+	(float)-0.23924057925542965158, (float)-0.13865235703915925642, (float) 0.43587843191057992846, (float) 0.65903257226026665927,
+	(float) 0.24361815372443152787, (float)-0.00235974960154720097, (float) 0.01844166574603346289, (float) 0.01722945988740875099
+};
+
+
+static double scalar16_(const float* x, const float* y)
+{
+	return
+		x[ 0]*y[ 0] + x[ 1]*y[ 1] + x[ 2]*y[ 2] + x[ 3]*y[ 3] +
+		x[ 4]*y[ 4] + x[ 5]*y[ 5] + x[ 6]*y[ 6] + x[ 7]*y[ 7] +
+		x[ 8]*y[ 8] + x[ 9]*y[ 9] + x[10]*y[10] + x[11]*y[11] +
+		x[12]*y[12] + x[13]*y[13] + x[14]*y[14] + x[15]*y[15];
+}
+
+
+void FLAC__plugin_common__init_dither_context(DitherContext *d, int bits, int shapingtype)
+{
+	static unsigned char default_dither [] = { 92, 92, 88, 84, 81, 78, 74, 67,  0,  0 };
+	static const float*               F [] = { F44_0, F44_1, F44_2, F44_3 };
+
+	int index;
+
+	if (shapingtype < 0) shapingtype = 0;
+	if (shapingtype > 3) shapingtype = 3;
+	index = bits - 11 - shapingtype;
+	if (index < 0) index = 0;
+	if (index > 9) index = 9;
+
+	memset ( d->ErrorHistory , 0, sizeof (d->ErrorHistory ) );
+	memset ( d->DitherHistory, 0, sizeof (d->DitherHistory) );
+
+	d->FilterCoeff = F [shapingtype];
+	d->Mask   = ((FLAC__uint64)-1) << (32 - bits);
+	d->Add    = 0.5     * ((1L << (32 - bits)) - 1);
+	d->Dither = 0.01*default_dither[index] / (((FLAC__int64)1) << bits);
+}
+
+/*
+ * the following is based on parts of wavegain.c
+ */
+
+static FLAC__INLINE FLAC__int64 dither_output_(DitherContext *d, FLAC__bool noise_shaping, int shapingtype, int i, double Sum, int k)
+{
+	double doubletmp, Sum2;
+	FLAC__int64 val;
+
+#define ROUND64(x)   ( doubletmp = (x) + d->Add + (FLAC__int64)0x001FFFFD80000000L, *(FLAC__int64*)(&doubletmp) - (FLAC__int64)0x433FFFFD80000000L )
+
+	if(noise_shaping) {
+		if(shapingtype == 0) {
+			double  tmp = random_equi_(d->Dither);
+			Sum2 = tmp - d->LastRandomNumber [k];
+			d->LastRandomNumber [k] = tmp;
+			Sum2 = Sum += Sum2;
+			val = ROUND64(Sum2) & d->Mask;
+		}
+		else {
+			Sum2 = random_triangular_(d->Dither) - scalar16_(d->DitherHistory[k], d->FilterCoeff + i);
+			Sum += d->DitherHistory [k] [(-1-i)&15] = Sum2;
+			Sum2 = Sum + scalar16_(d->ErrorHistory [k], d->FilterCoeff + i);
+			val = ROUND64(Sum2) & d->Mask;
+			d->ErrorHistory [k] [(-1-i)&15] = (float)(Sum - val);
+		}
+		return val;
+	}
+	else
+		return ROUND64(Sum);
+
+#undef ROUND64
+}
+
+#if 0
+	Init_Dither (&dither_, settings->outbitwidth, settings->shapingtype)
+
+	float        peak = 0.f,
+	             new_peak,
+	             factor_clip
+	double       scale,
+	             dB;
+
+	...
+
+	peak is in the range -32768.0 .. 32767.0
+
+	/* calculate factors for ReplayGain and ClippingPrevention */
+	*track_gain = GetTitleGain() + settings->man_gain;
+	scale = (float) pow(10., *track_gain * 0.05);
+	if(settings->clip_prev) {
+		factor_clip  = (float) (32767./( peak + 1));
+		if(scale < factor_clip)
+			factor_clip = 1.f;
+		else
+			factor_clip /= scale;
+		scale *= factor_clip;
+	}
+	new_peak = (float) peak * scale;
+
+	dB = 20. * log10(scale);
+	*track_gain = (float) dB;
+
+ 	const double scale = (float) pow(10., (double)gain * 0.05); /*@@@@ why downcast pow() output to float? */
+#endif
+
+
+PLUGIN_COMMON_API int FLAC__plugin_common_apply_gain(FLAC__byte *data_out, FLAC__int32 *input, unsigned wide_samples, unsigned channels, const unsigned source_bps, const unsigned target_bps, const float scale, const FLAC__bool hard_limit, FLAC__bool do_dithering, NoiseShaping noise_shaping, DitherContext *dither_context)
+{
+	static const FLAC__int32 conv_factors_[33] = {
+		-1, /* 0 bits-per-sample (not supported) */
+		-1, /* 1 bits-per-sample (not supported) */
+		-1, /* 2 bits-per-sample (not supported) */
+		-1, /* 3 bits-per-sample (not supported) */
+		268435456, /* 4 bits-per-sample */
+		134217728, /* 5 bits-per-sample */
+		67108864, /* 6 bits-per-sample */
+		33554432, /* 7 bits-per-sample */
+		16777216, /* 8 bits-per-sample */
+		8388608, /* 9 bits-per-sample */
+		4194304, /* 10 bits-per-sample */
+		2097152, /* 11 bits-per-sample */
+		1048576, /* 12 bits-per-sample */
+		524288, /* 13 bits-per-sample */
+		262144, /* 14 bits-per-sample */
+		131072, /* 15 bits-per-sample */
+		65536, /* 16 bits-per-sample */
+		32768, /* 17 bits-per-sample */
+		16384, /* 18 bits-per-sample */
+		8192, /* 19 bits-per-sample */
+		4096, /* 20 bits-per-sample */
+		2048, /* 21 bits-per-sample */
+		1024, /* 22 bits-per-sample */
+		512, /* 23 bits-per-sample */
+		256, /* 24 bits-per-sample */
+		128, /* 25 bits-per-sample */
+		64, /* 26 bits-per-sample */
+		32, /* 27 bits-per-sample */
+		16, /* 28 bits-per-sample */
+		8, /* 29 bits-per-sample */
+		4, /* 30 bits-per-sample */
+		2, /* 31 bits-per-sample */
+		1 /* 32 bits-per-sample */
+	};
+	static const FLAC__int64 hard_clip_factors_[33] = {
+		0, /* 0 bits-per-sample (not supported) */
+		0, /* 1 bits-per-sample (not supported) */
+		0, /* 2 bits-per-sample (not supported) */
+		0, /* 3 bits-per-sample (not supported) */
+		-8, /* 4 bits-per-sample */
+		-16, /* 5 bits-per-sample */
+		-32, /* 6 bits-per-sample */
+		-64, /* 7 bits-per-sample */
+		-128, /* 8 bits-per-sample */
+		-256, /* 9 bits-per-sample */
+		-512, /* 10 bits-per-sample */
+		-1024, /* 11 bits-per-sample */
+		-2048, /* 12 bits-per-sample */
+		-4096, /* 13 bits-per-sample */
+		-8192, /* 14 bits-per-sample */
+		-16384, /* 15 bits-per-sample */
+		-32768, /* 16 bits-per-sample */
+		-65536, /* 17 bits-per-sample */
+		-131072, /* 18 bits-per-sample */
+		-262144, /* 19 bits-per-sample */
+		-524288, /* 20 bits-per-sample */
+		-1048576, /* 21 bits-per-sample */
+		-2097152, /* 22 bits-per-sample */
+		-4194304, /* 23 bits-per-sample */
+		-8388608, /* 24 bits-per-sample */
+		-16777216, /* 25 bits-per-sample */
+		-33554432, /* 26 bits-per-sample */
+		-67108864, /* 27 bits-per-sample */
+		-134217728, /* 28 bits-per-sample */
+		-268435456, /* 29 bits-per-sample */
+		-536870912, /* 30 bits-per-sample */
+		-1073741824, /* 31 bits-per-sample */
+		-2147483648ll /* 32 bits-per-sample */
+	};
+	const FLAC__int32 conv_factor = conv_factors_[source_bps];
+	const FLAC__int64 hard_clip_factor = hard_clip_factors_[source_bps];
+	/*
+	 * The integer input coming in has a varying range based on the
+	 * source_bps.  We want to normalize it to [-1.0, 1.0) so instead
+	 * of doing two multiplies on each sample, we just multiple
+	 * 'scale' by 1/(2^(source_bps-1))
+	 */
+	const double multi_scale = scale / (double)(1u << (source_bps-1));
+
+	FLAC__byte * const start = data_out;
+	const unsigned samples = wide_samples * channels;
+	const unsigned dither_twiggle = channels - 1;
+	unsigned dither_source = 0;
+	unsigned i;
+	int coeff;
+	double sample;
+
+	FLAC__ASSERT(FLAC_PLUGIN__MAX_SUPPORTED_CHANNELS == 2);
+	FLAC__ASSERT(channels > 0 && channels <= FLAC_PLUGIN__MAX_SUPPORTED_CHANNELS);
+	FLAC__ASSERT(source_bps >= 4);
+	FLAC__ASSERT(target_bps >= 4);
+	FLAC__ASSERT(source_bps <= 32);
+	FLAC__ASSERT(target_bps < 32);
+	FLAC__ASSERT((target_bps & 7) == 0);
+
+	coeff = 0;
+	for(i = 0; i < samples; i++, coeff++) {
+		sample = (double)input[i] * multi_scale;
+
+		if(hard_limit) {
+			/* hard 6dB limiting */
+			if(sample < -0.5)
+				sample = tanh((sample + 0.5) / (1-0.5)) * (1-0.5) - 0.5;
+			else if(sample > 0.5)
+				sample = tanh((sample - 0.5) / (1-0.5)) * (1-0.5) + 0.5;
+		}
+		sample *= 2147483647.f;
+
+		{
+			FLAC__int64 val64;
+			FLAC__int32 val32;
+
+			if(coeff >= (32<<dither_twiggle))
+				coeff = 0;
+
+			/* 'coeff>>dither_twiggle' is the same as 'coeff/channels' */
+			val64 = dither_output_(dither_context, do_dithering, noise_shaping, coeff>>dither_twiggle, sample, dither_source) / conv_factor;
+
+			dither_source ^= dither_twiggle;
+
+			val32 = (FLAC__int32)val64;
+			if(val64 >= -hard_clip_factor)
+				val32 = (FLAC__int32)(-(hard_clip_factor+1));
+			else if(val64 < hard_clip_factor)
+				val32 = (FLAC__int32)hard_clip_factor;
+
+			switch(target_bps) {
+				case 8:
+					data_out[0] = val32 ^ 0x80;
+					break;
+				case 24:
+					data_out[2] = (FLAC__byte)(val32 >> 16);
+					/* fall through */
+				case 16:
+					data_out[1] = (FLAC__byte)(val32 >> 8);
+					data_out[0] = (FLAC__byte)val32;
+			}
+		}
+
+		data_out += target_bps/8;
+	}
+
+	return data_out - start;
+}
diff --git a/src/plugin_common/replaygain_synthesis.h b/src/plugin_common/replaygain_synthesis.h
new file mode 100644
index 00000000..1db5fa8e
--- /dev/null
+++ b/src/plugin_common/replaygain_synthesis.h
@@ -0,0 +1,49 @@
+/* plugin_common - Routines common to several plugins
+ * Copyright (C) 2002  Josh Coalson
+ *
+ * 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__REPLAYGAIN_SYNTHESIS_H
+#define FLAC__PLUGIN_COMMON__REPLAYGAIN_SYNTHESIS_H
+
+#include "export.h"
+
+#include "defs.h"
+#include "FLAC/ordinals.h"
+
+typedef struct {
+	const float*  FilterCoeff;
+	FLAC__uint64  Mask;
+	double        Add;
+	float         Dither;
+	float         ErrorHistory     [FLAC_PLUGIN__MAX_SUPPORTED_CHANNELS] [16];  /* 16th order Noise shaping */
+	float         DitherHistory    [FLAC_PLUGIN__MAX_SUPPORTED_CHANNELS] [16];
+	int           LastRandomNumber [FLAC_PLUGIN__MAX_SUPPORTED_CHANNELS];
+} DitherContext;
+
+typedef enum {
+	NOISE_SHAPING_NONE = 0,
+	NOISE_SHAPING_LOW = 1,
+	NOISE_SHAPING_MEDUIM = 2,
+	NOISE_SHAPING_HIGH = 3
+} NoiseShaping;
+
+PLUGIN_COMMON_API void FLAC__plugin_common__init_dither_context(DitherContext *dither, int bits, int shapingtype);
+
+/* scale = (float) pow(10., (double)replaygain * 0.05); */
+PLUGIN_COMMON_API int FLAC__plugin_common_apply_gain(FLAC__byte *data_out, FLAC__int32 *input, unsigned wide_samples, unsigned channels, const unsigned source_bps, const unsigned target_bps, const float scale, const FLAC__bool hard_limit, FLAC__bool do_dithering, NoiseShaping noise_shaping, DitherContext *dither_context);
+
+#endif