/* * libmad - MPEG audio decoder library * Copyright (C) 2000-2004 Underbit Technologies, Inc. * * 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 * * $Id: synth.c,v 1.25 2004/01/23 09:41:33 rob Exp $ */#  define mad_f_mul(x, y)   ((x) * (y))# ifdef HAVE_CONFIG_H#  include "config.h"# endif# include "global.h"# include "fixed.h"# include "frame.h"# include "synth.h"/* * NAME:	synth->init() * DESCRIPTION:	initialize synth struct */void mad_synth_init(struct mad_synth *synth){  mad_synth_mute(synth);  synth->phase = 0;  synth->pcm.samplerate = 0;  synth->pcm.channels   = 0;  synth->pcm.length     = 0;}/* * NAME:	synth->mute() * DESCRIPTION:	zero all polyphase filterbank values, resetting synthesis */void mad_synth_mute(struct mad_synth *synth){  unsigned int ch, s, v;  for (ch = 0; ch < 2; ++ch) {    for (s = 0; s < 16; ++s) {      for (v = 0; v < 8; ++v) {	synth->filter[ch][0][0][s][v] = synth->filter[ch][0][1][s][v] =	synth->filter[ch][1][0][s][v] = synth->filter[ch][1][1][s][v] = 0;      }    }  }}/* * An optional optimization called here the Subband Synthesis Optimization * (SSO) improves the performance of subband synthesis at the expense of * accuracy. * * The idea is to simplify 32x32->64-bit multiplication to 32x32->32 such * that extra scaling and rounding are not necessary. This often allows the * compiler to use faster 32-bit multiply-accumulate instructions instead of * explicit 64-bit multiply, shift, and add instructions. * * SSO works like this: a full 32x32->64-bit multiply of two mad_fixed_t * values requires the result to be right-shifted 28 bits to be properly * scaled to the same fixed-point format. Right shifts can be applied at any * time to either operand or to the result, so the optimization involves * careful placement of these shifts to minimize the loss of accuracy. * * First, a 14-bit shift is applied with rounding at compile-time to the D[] * table of coefficients for the subband synthesis window. This only loses 2 * bits of accuracy because the lower 12 bits are always zero. A second * 12-bit shift occurs after the DCT calculation. This loses 12 bits of * accuracy. Finally, a third 2-bit shift occurs just before the sample is * saved in the PCM buffer. 14 + 12 + 2 == 28 bits. *//* FPM_DEFAULT without OPT_SSO will actually lose accuracy and performance */# if defined(FPM_DEFAULT) && !defined(OPT_SSO)#  define OPT_SSO# endif/* second SSO shift, with rounding */# if defined(OPT_SSO)#  define SHIFT(x)  (((x) + (1L << 11)) >> 12)# else#  define SHIFT(x)  (x)# endif/* possible DCT speed optimization */# if defined(OPT_SPEED) && defined(MAD_F_MLX)#  define OPT_DCTO#  define MUL(x, y)  \    ({ mad_fixed64hi_t hi;  \       mad_fixed64lo_t lo;  \       MAD_F_MLX(hi, lo, (x), (y));  \       hi << (32 - MAD_F_SCALEBITS - 3);  \    })# else#  undef OPT_DCTO#  define MUL(x, y)  mad_f_mul((x), (y))# endif/* * NAME:	dct32() * DESCRIPTION:	perform fast in[32]->out[32] DCT */staticvoid dct32(mad_fixed_t const in[32], unsigned int slot,	   mad_fixed_t lo[16][8], mad_fixed_t hi[16][8]){  mad_fixed_t t0,   t1,   t2,   t3,   t4,   t5,   t6,   t7;  mad_fixed_t t8,   t9,   t10,  t11,  t12,  t13,  t14,  t15;  mad_fixed_t t16,  t17,  t18,  t19,  t20,  t21,  t22,  t23;  mad_fixed_t t24,  t25,  t26,  t27,  t28,  t29,  t30,  t31;  mad_fixed_t t32,  t33,  t34,  t35,  t36,  t37,  t38,  t39;  mad_fixed_t t40,  t41,  t42,  t43,  t44,  t45,  t46,  t47;  mad_fixed_t t48,  t49,  t50,  t51,  t52,  t53,  t54,  t55;  mad_fixed_t t56,  t57,  t58,  t59,  t60,  t61,  t62,  t63;  mad_fixed_t t64,  t65,  t66,  t67,  t68,  t69,  t70,  t71;  mad_fixed_t t72,  t73,  t74,  t75,  t76,  t77,  t78,  t79;  mad_fixed_t t80,  t81,  t82,  t83,  t84,  t85,  t86,  t87;  mad_fixed_t t88,  t89,  t90,  t91,  t92,  t93,  t94,  t95;  mad_fixed_t t96,  t97,  t98,  t99,  t100, t101, t102, t103;  mad_fixed_t t104, t105, t106, t107, t108, t109, t110, t111;  mad_fixed_t t112, t113, t114, t115, t116, t117, t118, t119;  mad_fixed_t t120, t121, t122, t123, t124, t125, t126, t127;  mad_fixed_t t128, t129, t130, t131, t132, t133, t134, t135;  mad_fixed_t t136, t137, t138, t139, t140, t141, t142, t143;  mad_fixed_t t144, t145, t146, t147, t148, t149, t150, t151;  mad_fixed_t t152, t153, t154, t155, t156, t157, t158, t159;  mad_fixed_t t160, t161, t162, t163, t164, t165, t166, t167;  mad_fixed_t t168, t169, t170, t171, t172, t173, t174, t175;  mad_fixed_t t176;  /* costab[i] = cos(PI / (2 * 32) * i) */# if defined(OPT_DCTO)#  define costab1	MAD_F(0x7fd8878e)#  define costab2	MAD_F(0x7f62368f)#  define costab3	MAD_F(0x7e9d55fc)#  define costab4	MAD_F(0x7d8a5f40)#  define costab5	MAD_F(0x7c29fbee)#  define costab6	MAD_F(0x7a7d055b)#  define costab7	MAD_F(0x78848414)#  define costab8	MAD_F(0x7641af3d)#  define costab9	MAD_F(0x73b5ebd1)#  define costab10	MAD_F(0x70e2cbc6)#  define costab11	MAD_F(0x6dca0d14)#  define costab12	MAD_F(0x6a6d98a4)#  define costab13	MAD_F(0x66cf8120)#  define costab14	MAD_F(0x62f201ac)#  define costab15	MAD_F(0x5ed77c8a)#  define costab16	MAD_F(0x5a82799a)#  define costab17	MAD_F(0x55f5a4d2)#  define costab18	MAD_F(0x5133cc94)#  define costab19	MAD_F(0x4c3fdff4)#  define costab20	MAD_F(0x471cece7)#  define costab21	MAD_F(0x41ce1e65)#  define costab22	MAD_F(0x3c56ba70)#  define costab23	MAD_F(0x36ba2014)#  define costab24	MAD_F(0x30fbc54d)#  define costab25	MAD_F(0x2b1f34eb)#  define costab26	MAD_F(0x25280c5e)#  define costab27	MAD_F(0x1f19f97b)#  define costab28	MAD_F(0x18f8b83c)#  define costab29	MAD_F(0x12c8106f)#  define costab30	MAD_F(0x0c8bd35e)#  define costab31	MAD_F(0x0647d97c)# else#  define costab1	MAD_F(0x0ffb10f2)  /* 0.998795456 */#  define costab2	MAD_F(0x0fec46d2)  /* 0.995184727 */#  define costab3	MAD_F(0x0fd3aac0)  /* 0.989176510 */#  define costab4	MAD_F(0x0fb14be8)  /* 0.980785280 */#  define costab5	MAD_F(0x0f853f7e)  /* 0.970031253 */#  define costab6	MAD_F(0x0f4fa0ab)  /* 0.956940336 */#  define costab7	MAD_F(0x0f109082)  /* 0.941544065 */#  define costab8	MAD_F(0x0ec835e8)  /* 0.923879533 */#  define costab9	MAD_F(0x0e76bd7a)  /* 0.903989293 */#  define costab10	MAD_F(0x0e1c5979)  /* 0.881921264 */#  define costab11	MAD_F(0x0db941a3)  /* 0.857728610 */#  define costab12	MAD_F(0x0d4db315)  /* 0.831469612 */#  define costab13	MAD_F(0x0cd9f024)  /* 0.803207531 */#  define costab14	MAD_F(0x0c5e4036)  /* 0.773010453 */#  define costab15	MAD_F(0x0bdaef91)  /* 0.740951125 */#  define costab16	MAD_F(0x0b504f33)  /* 0.707106781 */#  define costab17	MAD_F(0x0abeb49a)  /* 0.671558955 */#  define costab18	MAD_F(0x0a267993)  /* 0.634393284 */#  define costab19	MAD_F(0x0987fbfe)  /* 0.595699304 */#  define costab20	MAD_F(0x08e39d9d)  /* 0.555570233 */#  define costab21	MAD_F(0x0839c3cd)  /* 0.514102744 */#  define costab22	MAD_F(0x078ad74e)  /* 0.471396737 */#  define costab23	MAD_F(0x06d74402)  /* 0.427555093 */#  define costab24	MAD_F(0x061f78aa)  /* 0.382683432 */#  define costab25	MAD_F(0x0563e69d)  /* 0.336889853 */#  define costab26	MAD_F(0x04a5018c)  /* 0.290284677 */#  define costab27	MAD_F(0x03e33f2f)  /* 0.242980180 */#  define costab28	MAD_F(0x031f1708)  /* 0.195090322 */#  define costab29	MAD_F(0x0259020e)  /* 0.146730474 */#  define costab30	MAD_F(0x01917a6c)  /* 0.098017140 */#  define costab31	MAD_F(0x00c8fb30)  /* 0.049067674 */# endif  t0   = in[0]  + in[31];  t16  = MUL(in[0]  - in[31], costab1);  t1   = in[15] + in[16];  t17  = MUL(in[15] - in[16], costab31);  t41  = t16 + t17;  t59  = MUL(t16 - t17, costab2);  t33  = t0  + t1;  t50  = MUL(t0  - t1,  costab2);  t2   = in[7]  + in[24];  t18  = MUL(in[7]  - in[24], costab15);  t3   = in[8]  + in[23];  t19  = MUL(in[8]  - in[23], costab17);  t42  = t18 + t19;  t60  = MUL(t18 - t19, costab30);  t34  = t2  + t3;  t51  = MUL(t2  - t3,  costab30);  t4   = in[3]  + in[28];  t20  = MUL(in[3]  - in[28], costab7);  t5   = in[12] + in[19];  t21  = MUL(in[12] - in[19], costab25);  t43  = t20 + t21;  t61  = MUL(t20 - t21, costab14);  t35  = t4  + t5;  t52  = MUL(t4  - t5,  costab14);  t6   = in[4]  + in[27];  t22  = MUL(in[4]  - in[27], costab9);  t7   = in[11] + in[20];  t23  = MUL(in[11] - in[20], costab23);  t44  = t22 + t23;  t62  = MUL(t22 - t23, costab18);  t36  = t6  + t7;  t53  = MUL(t6  - t7,  costab18);  t8   = in[1]  + in[30];  t24  = MUL(in[1]  - in[30], costab3);  t9   = in[14] + in[17];  t25  = MUL(in[14] - in[17], costab29);  t45  = t24 + t25;  t63  = MUL(t24 - t25, costab6);  t37  = t8  + t9;  t54  = MUL(t8  - t9,  costab6);  t10  = in[6]  + in[25];  t26  = MUL(in[6]  - in[25], costab13);  t11  = in[9]  + in[22];  t27  = MUL(in[9]  - in[22], costab19);  t46  = t26 + t27;  t64  = MUL(t26 - t27, costab26);  t38  = t10 + t11;  t55  = MUL(t10 - t11, costab26);  t12  = in[2]  + in[29];  t28  = MUL(in[2]  - in[29], costab5);  t13  = in[13] + in[18];  t29  = MUL(in[13] - in[18], costab27);  t47  = t28 + t29;  t65  = MUL(t28 - t29, costab10);  t39  = t12 + t13;  t56  = MUL(t12 - t13, costab10);  t14  = in[5]  + in[26];  t30  = MUL(in[5]  - in[26], costab11);  t15  = in[10] + in[21];  t31  = MUL(in[10] - in[21], costab21);  t48  = t30 + t31;  t66  = MUL(t30 - t31, costab22);  t40  = t14 + t15;  t57  = MUL(t14 - t15, costab22);  t69  = t33 + t34;  t89  = MUL(t33 - t34, costab4);  t70  = t35 + t36;  t90  = MUL(t35 - t36, costab28);  t71  = t37 + t38;  t91  = MUL(t37 - t38, costab12);  t72  = t39 + t40;  t92  = MUL(t39 - t40, costab20);  t73  = t41 + t42;  t94  = MUL(t41 - t42, costab4);  t74  = t43 + t44;  t95  = MUL(t43 - t44, costab28);  t75  = t45 + t46;  t96  = MUL(t45 - t46, costab12);  t76  = t47 + t48;  t97  = MUL(t47 - t48, costab20);  t78  = t50 + t51;  t100 = MUL(t50 - t51, costab4);  t79  = t52 + t53;  t101 = MUL(t52 - t53, costab28);  t80  = t54 + t55;  t102 = MUL(t54 - t55, costab12);  t81  = t56 + t57;  t103 = MUL(t56 - t57, costab20);  t83  = t59 + t60;  t106 = MUL(t59 - t60, costab4);  t84  = t61 + t62;  t107 = MUL(t61 - t62, costab28);  t85  = t63 + t64;  t108 = MUL(t63 - t64, costab12);  t86  = t65 + t66;  t109 = MUL(t65 - t66, costab20);  t113 = t69  + t70;  t114 = t71  + t72;  /*  0 */ hi[15][slot] = SHIFT(t113 + t114);  /* 16 */ lo[ 0][slot] = SHIFT(MUL(t113 - t114, costab16));  t115 = t73  + t74;  t116 = t75  + t76;  t32  = t115 + t116;  /*  1 */ hi[14][slot] = SHIFT(t32);  t118 = t78  + t79;  t119 = t80  + t81;  t58  = t118 + t119;  /*  2 */ hi[13][slot] = SHIFT(t58);  t121 = t83  + t84;  t122 = t85  + t86;  t67  = t121 + t122;  t49  = (t67 * 2) - t32;  /*  3 */ hi[12][slot] = SHIFT(t49);  t125 = t89  + t90;  t126 = t91  + t92;  t93  = t125 + t126;  /*  4 */ hi[11][slot] = SHIFT(t93);  t128 = t94  + t95;  t129 = t96  + t97;  t98  = t128 + t129;  t68  = (t98 * 2) - t49;  /*  5 */ hi[10][slot] = SHIFT(t68);  t132 = t100 + t101;  t133 = t102 + t103;  t104 = t132 + t133;  t82  = (t104 * 2) - t58;  /*  6 */ hi[ 9][slot] = SHIFT(t82);  t136 = t106 + t107;  t137 = t108 + t109;  t110 = t136 + t137;  t87  = (t110 * 2) - t67;  t77  = (t87 * 2) - t68;  /*  7 */ hi[ 8][slot] = SHIFT(t77);  t141 = MUL(t69 - t70, costab8);  t142 = MUL(t71 - t72, costab24);  t143 = t141 + t142;  /*  8 */ hi[ 7][slot] = SHIFT(t143);  /* 24 */ lo[ 8][slot] =	     SHIFT((MUL(t141 - t142, costab16) * 2) - t143);  t144 = MUL(t73 - t74, costab8);  t145 = MUL(t75 - t76, costab24);  t146 = t144 + t145;  t88  = (t146 * 2) - t77;  /*  9 */ hi[ 6][slot] = SHIFT(t88);  t148 = MUL(t78 - t79, costab8);  t149 = MUL(t80 - t81, costab24);  t150 = t148 + t149;  t105 = (t150 * 2) - t82;  /* 10 */ hi[ 5][slot] = SHIFT(t105);  t152 = MUL(t83 - t84, costab8);  t153 = MUL(t85 - t86, costab24);  t154 = t152 + t153;  t111 = (t154 * 2) - t87;  t99  = (t111 * 2) - t88;  /* 11 */ hi[ 4][slot] = SHIFT(t99);  t157 = MUL(t89 - t90, costab8);  t158 = MUL(t91 - t92, costab24);  t159 = t157 + t158;  t127 = (t159 * 2) - t93;  /* 12 */ hi[ 3][slot] = SHIFT(t127);  t160 = (MUL(t125 - t126, costab16) * 2) - t127;  /* 20 */ lo[ 4][slot] = SHIFT(t160);  /* 28 */ lo[12][slot] =	     SHIFT((((MUL(t157 - t158, costab16) * 2) - t159) * 2) - t160);  t161 = MUL(t94 - t95, costab8);  t162 = MUL(t96 - t97, costab24);  t163 = t161 + t162;  t130 = (t163 * 2) - t98;  t112 = (t130 * 2) - t99;  /* 13 */ hi[ 2][slot] = SHIFT(t112);  t164 = (MUL(t128 - t129, costab16) * 2) - t130;  t166 = MUL(t100 - t101, costab8);