replaygain_synthesis.c

这是著名的TCPMP播放器在WINDWOWS,和WINCE下编译通过的源程序.笔者对其中的LIBMAD库做了针对ARM MPU的优化. 并增加了词幕功能.

/* replaygain_synthesis - Routines for applying ReplayGain to a signal
 * Copyright (C) 2002,2003,2004,2005  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

/* adjust for compilers that can't understand using LL suffix for int64_t literals */
#ifdef _MSC_VER
#define FLAC__I64L(x) x
#else
#define FLAC__I64L(x) x##LL
#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__replaygain_synthesis__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;
	d->ShapingType = (NoiseShaping)shapingtype;
	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 = 0.01f*default_dither[index] / (((FLAC__int64)1) << bits);
	d->LastHistoryIndex = 0;
}

/*