/*____________________________________________________________________________ FreeAmp - The Free MP3 Player MP3 Decoder originally Copyright (C) 1995-1997 Xing Technology Corp. http://www.xingtech.com Portions Copyright (C) 1998 EMusic.com 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., 675 Mass Ave, Cambridge, MA 02139, USA. $Id$ ____________________________________________________________________________*/ /**** tinit.c *************************************************** Layer III init tables ******************************************************************/ #include #include #include #include #include "L3.h" #include "mhead.h" #include "protos.h" /* get rid of precision loss warnings on conversion */ #ifdef _MSC_VER #pragma warning(disable:4244 4056) #endif static const float Ci[8] = { -0.6f, -0.535f, -0.33f, -0.185f, -0.095f, -0.041f, -0.0142f, -0.0037f}; void hwin_init(MPEG *m); /* hybrid windows -- */ void imdct_init(MPEG *m); typedef struct { float *w; float *w2; void *coef; } IMDCT_INIT_BLOCK; void msis_init(MPEG *m); void msis_init_MPEG2(MPEG *m); /*=============================================================*/ int L3table_init(MPEG *m) { int i; float *x; LS *ls; int scalefact_scale, preemp, scalefac; double tmp; PAIR *csa; /*================ quant ===============================*/ /* 8 bit plus 2 lookup x = pow(2.0, 0.25*(global_gain-210)) */ /* extra 2 for ms scaling by 1/sqrt(2) */ /* extra 4 for cvt to mono scaling by 1/2 */ x = quant_init_global_addr(m); for (i = 0; i < 256 + 2 + 4; i++) x[i] = (float) pow(2.0, 0.25 * ((i - (2 + 4)) - 210 + GLOBAL_GAIN_SCALE)); /* x = pow(2.0, -0.5*(1+scalefact_scale)*scalefac + preemp) */ ls = quant_init_scale_addr(m); for (scalefact_scale = 0; scalefact_scale < 2; scalefact_scale++) { for (preemp = 0; preemp < 4; preemp++) { for (scalefac = 0; scalefac < 32; scalefac++) { ls[scalefact_scale][preemp][scalefac] = (float) pow(2.0, -0.5 * (1 + scalefact_scale) * (scalefac + preemp)); } } } /*--- iSample**(4/3) lookup, -32<=i<=31 ---*/ x = quant_init_pow_addr(m); for (i = 0; i < 64; i++) { tmp = i - 32; x[i] = (float) (tmp * pow(fabs(tmp), (1.0 / 3.0))); } /*-- pow(2.0, -0.25*8.0*subblock_gain) 3 bits --*/ x = quant_init_subblock_addr(m); for (i = 0; i < 8; i++) { x[i] = (float) pow(2.0, 0.25 * -8.0 * i); } /*-------------------------*/ // quant_init_sf_band(sr_index); replaced by code in sup.c /*================ antialias ===============================*/ csa = alias_init_addr(m); for (i = 0; i < 8; i++) { csa[i][0] = (float) (1.0 / sqrt(1.0 + Ci[i] * Ci[i])); csa[i][1] = (float) (Ci[i] / sqrt(1.0 + Ci[i] * Ci[i])); } /*================ msis ===============================*/ msis_init(m); msis_init_MPEG2(m); /*================ imdct ===============================*/ imdct_init(m); /*--- hybrid windows ------------*/ hwin_init(m); return 0; } /*====================================================================*/ typedef float ARRAY36[36]; ARRAY36 *hwin_init_addr(); /*--------------------------------------------------------------------*/ void hwin_init(MPEG *m) { int i, j; double pi; ARRAY36 *win; win = hwin_init_addr(m); pi = 4.0 * atan(1.0); /* type 0 */ for (i = 0; i < 36; i++) win[0][i] = (float) sin(pi / 36 * (i + 0.5)); /* type 1 */ for (i = 0; i < 18; i++) win[1][i] = (float) sin(pi / 36 * (i + 0.5)); for (i = 18; i < 24; i++) win[1][i] = 1.0F; for (i = 24; i < 30; i++) win[1][i] = (float) sin(pi / 12 * (i + 0.5 - 18)); for (i = 30; i < 36; i++) win[1][i] = 0.0F; /* type 3 */ for (i = 0; i < 6; i++) win[3][i] = 0.0F; for (i = 6; i < 12; i++) win[3][i] = (float) sin(pi / 12 * (i + 0.5 - 6)); for (i = 12; i < 18; i++) win[3][i] = 1.0F; for (i = 18; i < 36; i++) win[3][i] = (float) sin(pi / 36 * (i + 0.5)); /* type 2 */ for (i = 0; i < 12; i++) win[2][i] = (float) sin(pi / 12 * (i + 0.5)); for (i = 12; i < 36; i++) win[2][i] = 0.0F; /*--- invert signs by region to match mdct 18pt --> 36pt mapping */ for (j = 0; j < 4; j++) { if (j == 2) continue; for (i = 9; i < 36; i++) win[j][i] = -win[j][i]; } /*-- invert signs for short blocks --*/ for (i = 3; i < 12; i++) win[2][i] = -win[2][i]; return; } /*=============================================================*/ typedef float ARRAY4[4]; IMDCT_INIT_BLOCK *imdct_init_addr_18(); IMDCT_INIT_BLOCK *imdct_init_addr_6(); /*-------------------------------------------------------------*/ void imdct_init(MPEG *m) { int k, p, n; double t, pi; IMDCT_INIT_BLOCK *addr; float *w, *w2; float *v, *v2, *coef87; ARRAY4 *coef; /*--- 18 point --*/ addr = imdct_init_addr_18(); w = addr->w; w2 = addr->w2; coef = addr->coef; /*----*/ n = 18; pi = 4.0 * atan(1.0); t = pi / (4 * n); for (p = 0; p < n; p++) w[p] = (float) (2.0 * cos(t * (2 * p + 1))); for (p = 0; p < 9; p++) w2[p] = (float) 2.0 *cos(2 * t * (2 * p + 1)); t = pi / (2 * n); for (k = 0; k < 9; k++) { for (p = 0; p < 4; p++) coef[k][p] = (float) cos(t * (2 * k) * (2 * p + 1)); } /*--- 6 point */ addr = imdct_init_addr_6(); v = addr->w; v2 = addr->w2; coef87 = addr->coef; /*----*/ n = 6; pi = 4.0 * atan(1.0); t = pi / (4 * n); for (p = 0; p < n; p++) v[p] = (float) 2.0 *cos(t * (2 * p + 1)); for (p = 0; p < 3; p++) v2[p] = (float) 2.0 *cos(2 * t * (2 * p + 1)); t = pi / (2 * n); k = 1; p = 0; *coef87 = (float) cos(t * (2 * k) * (2 * p + 1)); /* adjust scaling to save a few mults */ for (p = 0; p < 6; p++) v[p] = v[p] / 2.0f; *coef87 = (float) 2.0 *(*coef87); return; } /*===============================================================*/ typedef float ARRAY8_2[8][2]; ARRAY8_2 *msis_init_addr(MPEG *m); /*-------------------------------------------------------------*/ void msis_init(MPEG *m) { int i; double s, c; double pi; double t; ARRAY8_2 *lr; lr = msis_init_addr(m); pi = 4.0 * atan(1.0); t = pi / 12.0; for (i = 0; i < 7; i++) { s = sin(i * t); c = cos(i * t); /* ms_mode = 0 */ lr[0][i][0] = (float) (s / (s + c)); lr[0][i][1] = (float) (c / (s + c)); /* ms_mode = 1 */ lr[1][i][0] = (float) (sqrt(2.0) * (s / (s + c))); lr[1][i][1] = (float) (sqrt(2.0) * (c / (s + c))); } /* sf = 7 */ /* ms_mode = 0 */ lr[0][i][0] = 1.0f; lr[0][i][1] = 0.0f; /* ms_mode = 1, in is bands is routine does ms processing */ lr[1][i][0] = 1.0f; lr[1][i][1] = 1.0f; /*------- for(i=0;i<21;i++) nBand[0][i] = sfBandTable[sr_index].l[i+1] - sfBandTable[sr_index].l[i]; for(i=0;i<12;i++) nBand[1][i] = sfBandTable[sr_index].s[i+1] - sfBandTable[sr_index].s[i]; -------------*/ } /*-------------------------------------------------------------*/ /*===============================================================*/ typedef float ARRAY2_64_2[2][64][2]; ARRAY2_64_2 *msis_init_addr_MPEG2(MPEG *m); /*-------------------------------------------------------------*/ void msis_init_MPEG2(MPEG *m) { int k, n; double t; ARRAY2_64_2 *lr; int intensity_scale, ms_mode, sf, sflen; float ms_factor[2]; ms_factor[0] = 1.0; ms_factor[1] = (float) sqrt(2.0); lr = msis_init_addr_MPEG2(m); /* intensity stereo MPEG2 */ /* lr2[intensity_scale][ms_mode][sflen_offset+sf][left/right] */ for (intensity_scale = 0; intensity_scale < 2; intensity_scale++) { t = pow(2.0, -0.25 * (1 + intensity_scale)); for (ms_mode = 0; ms_mode < 2; ms_mode++) { n = 1; k = 0; for (sflen = 0; sflen < 6; sflen++) { for (sf = 0; sf < (n - 1); sf++, k++) { if (sf == 0) { lr[intensity_scale][ms_mode][k][0] = ms_factor[ms_mode] * 1.0f; lr[intensity_scale][ms_mode][k][1] = ms_factor[ms_mode] * 1.0f; } else if ((sf & 1)) { lr[intensity_scale][ms_mode][k][0] = (float) (ms_factor[ms_mode] * pow(t, (sf + 1) / 2)); lr[intensity_scale][ms_mode][k][1] = ms_factor[ms_mode] * 1.0f; } else { lr[intensity_scale][ms_mode][k][0] = ms_factor[ms_mode] * 1.0f; lr[intensity_scale][ms_mode][k][1] = (float) (ms_factor[ms_mode] * pow(t, sf / 2)); } } /* illegal is_pos used to do ms processing */ if (ms_mode == 0) { /* ms_mode = 0 */ lr[intensity_scale][ms_mode][k][0] = 1.0f; lr[intensity_scale][ms_mode][k][1] = 0.0f; } else { /* ms_mode = 1, in is bands is routine does ms processing */ lr[intensity_scale][ms_mode][k][0] = 1.0f; lr[intensity_scale][ms_mode][k][1] = 1.0f; } k++; n = n + n; } } } } /*-------------------------------------------------------------*/