/* ** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding ** Copyright (C) 2003 M. Bakker, Ahead Software AG, http://www.nero.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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. ** ** Any non-GPL usage of this software or parts of this software is strictly ** forbidden. ** ** Commercial non-GPL licensing of this software is possible. ** For more info contact Ahead Software through Mpeg4AAClicense@nero.com. ** ** $Id: specrec.c,v 1.27 2003/09/30 12:43:05 menno Exp $ **/ /* Spectral reconstruction: - grouping/sectioning - inverse quantization - applying scalefactors */ #include "common.h" #include "structs.h" #include #include "specrec.h" #include "syntax.h" #include "iq_table.h" #ifdef LD_DEC static uint8_t num_swb_512_window[] = { 0, 0, 0, 36, 36, 37, 31, 31, 0, 0, 0, 0 }; static uint8_t num_swb_480_window[] = { 0, 0, 0, 35, 35, 37, 30, 30, 0, 0, 0, 0 }; #endif static uint8_t num_swb_960_window[] = { 40, 40, 45, 49, 49, 49, 46, 46, 42, 42, 42, 40 }; static uint8_t num_swb_1024_window[] = { 41, 41, 47, 49, 49, 51, 47, 47, 43, 43, 43, 40 }; static uint8_t num_swb_128_window[] = { 12, 12, 12, 14, 14, 14, 15, 15, 15, 15, 15, 15 }; static uint16_t swb_offset_1024_96[] = { 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 64, 72, 80, 88, 96, 108, 120, 132, 144, 156, 172, 188, 212, 240, 276, 320, 384, 448, 512, 576, 640, 704, 768, 832, 896, 960, 1024 }; static uint16_t swb_offset_128_96[] = { 0, 4, 8, 12, 16, 20, 24, 32, 40, 48, 64, 92, 128 }; static uint16_t swb_offset_1024_64[] = { 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 64, 72, 80, 88, 100, 112, 124, 140, 156, 172, 192, 216, 240, 268, 304, 344, 384, 424, 464, 504, 544, 584, 624, 664, 704, 744, 784, 824, 864, 904, 944, 984, 1024 }; static uint16_t swb_offset_128_64[] = { 0, 4, 8, 12, 16, 20, 24, 32, 40, 48, 64, 92, 128 }; static uint16_t swb_offset_1024_48[] = { 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 48, 56, 64, 72, 80, 88, 96, 108, 120, 132, 144, 160, 176, 196, 216, 240, 264, 292, 320, 352, 384, 416, 448, 480, 512, 544, 576, 608, 640, 672, 704, 736, 768, 800, 832, 864, 896, 928, 1024 }; #ifdef LD_DEC static uint16_t swb_offset_512_48[] = { 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 60, 68, 76, 84, 92, 100, 112, 124, 136, 148, 164, 184, 208, 236, 268, 300, 332, 364, 396, 428, 460, 512 }; static uint16_t swb_offset_480_48[] = { 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 64, 72 ,80 ,88, 96, 108, 120, 132, 144, 156, 172, 188, 212, 240, 272, 304, 336, 368, 400, 432, 480 }; #endif static uint16_t swb_offset_128_48[] = { 0, 4, 8, 12, 16, 20, 28, 36, 44, 56, 68, 80, 96, 112, 128 }; static uint16_t swb_offset_1024_32[] = { 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 48, 56, 64, 72, 80, 88, 96, 108, 120, 132, 144, 160, 176, 196, 216, 240, 264, 292, 320, 352, 384, 416, 448, 480, 512, 544, 576, 608, 640, 672, 704, 736, 768, 800, 832, 864, 896, 928, 960, 992, 1024 }; #ifdef LD_DEC static uint16_t swb_offset_512_32[] = { 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 64, 72, 80, 88, 96, 108, 120, 132, 144, 160, 176, 192, 212, 236, 260, 288, 320, 352, 384, 416, 448, 480, 512 }; static uint16_t swb_offset_480_32[] = { 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 60, 64, 72, 80, 88, 96, 104, 112, 124, 136, 148, 164, 180, 200, 224, 256, 288, 320, 352, 384, 416, 448, 480 }; #endif static uint16_t swb_offset_1024_24[] = { 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 52, 60, 68, 76, 84, 92, 100, 108, 116, 124, 136, 148, 160, 172, 188, 204, 220, 240, 260, 284, 308, 336, 364, 396, 432, 468, 508, 552, 600, 652, 704, 768, 832, 896, 960, 1024 }; #ifdef LD_DEC static uint16_t swb_offset_512_24[] = { 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 52, 60, 68, 80, 92, 104, 120, 140, 164, 192, 224, 256, 288, 320, 352, 384, 416, 448, 480, 512 }; static uint16_t swb_offset_480_24[] = { 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 52, 60, 68, 80, 92, 104, 120, 140, 164, 192, 224, 256, 288, 320, 352, 384, 416, 448, 480 }; #endif static uint16_t swb_offset_128_24[] = { 0, 4, 8, 12, 16, 20, 24, 28, 36, 44, 52, 64, 76, 92, 108, 128 }; static uint16_t swb_offset_1024_16[] = { 0, 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 100, 112, 124, 136, 148, 160, 172, 184, 196, 212, 228, 244, 260, 280, 300, 320, 344, 368, 396, 424, 456, 492, 532, 572, 616, 664, 716, 772, 832, 896, 960, 1024 }; static uint16_t swb_offset_128_16[] = { 0, 4, 8, 12, 16, 20, 24, 28, 32, 40, 48, 60, 72, 88, 108, 128 }; static uint16_t swb_offset_1024_8[] = { 0, 12, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 172, 188, 204, 220, 236, 252, 268, 288, 308, 328, 348, 372, 396, 420, 448, 476, 508, 544, 580, 620, 664, 712, 764, 820, 880, 944, 1024 }; static uint16_t swb_offset_128_8[] = { 0, 4, 8, 12, 16, 20, 24, 28, 36, 44, 52, 60, 72, 88, 108, 128 }; static uint16_t *swb_offset_1024_window[] = { swb_offset_1024_96, /* 96000 */ swb_offset_1024_96, /* 88200 */ swb_offset_1024_64, /* 64000 */ swb_offset_1024_48, /* 48000 */ swb_offset_1024_48, /* 44100 */ swb_offset_1024_32, /* 32000 */ swb_offset_1024_24, /* 24000 */ swb_offset_1024_24, /* 22050 */ swb_offset_1024_16, /* 16000 */ swb_offset_1024_16, /* 12000 */ swb_offset_1024_16, /* 11025 */ swb_offset_1024_8 /* 8000 */ }; #ifdef LD_DEC static uint16_t *swb_offset_512_window[] = { 0, /* 96000 */ 0, /* 88200 */ 0, /* 64000 */ swb_offset_512_48, /* 48000 */ swb_offset_512_48, /* 44100 */ swb_offset_512_32, /* 32000 */ swb_offset_512_24, /* 24000 */ swb_offset_512_24, /* 22050 */ 0, /* 16000 */ 0, /* 12000 */ 0, /* 11025 */ 0 /* 8000 */ }; static uint16_t *swb_offset_480_window[] = { 0, /* 96000 */ 0, /* 88200 */ 0, /* 64000 */ swb_offset_480_48, /* 48000 */ swb_offset_480_48, /* 44100 */ swb_offset_480_32, /* 32000 */ swb_offset_480_24, /* 24000 */ swb_offset_480_24, /* 22050 */ 0, /* 16000 */ 0, /* 12000 */ 0, /* 11025 */ 0 /* 8000 */ }; #endif static uint16_t *swb_offset_128_window[] = { swb_offset_128_96, /* 96000 */ swb_offset_128_96, /* 88200 */ swb_offset_128_64, /* 64000 */ swb_offset_128_48, /* 48000 */ swb_offset_128_48, /* 44100 */ swb_offset_128_48, /* 32000 */ swb_offset_128_24, /* 24000 */ swb_offset_128_24, /* 22050 */ swb_offset_128_16, /* 16000 */ swb_offset_128_16, /* 12000 */ swb_offset_128_16, /* 11025 */ swb_offset_128_8 /* 8000 */ }; #define bit_set(A, B) ((A) & (1<<(B))) /* 4.5.2.3.4 */ /* - determine the number of windows in a window_sequence named num_windows - determine the number of window_groups named num_window_groups - determine the number of windows in each group named window_group_length[g] - determine the total number of scalefactor window bands named num_swb for the actual window type - determine swb_offset[swb], the offset of the first coefficient in scalefactor window band named swb of the window actually used - determine sect_sfb_offset[g][section],the offset of the first coefficient in section named section. This offset depends on window_sequence and scale_factor_grouping and is needed to decode the spectral_data(). */ uint8_t window_grouping_info(faacDecHandle hDecoder, ic_stream *ics) { uint8_t i, g; uint8_t sf_index = hDecoder->sf_index; switch (ics->window_sequence) { case ONLY_LONG_SEQUENCE: case LONG_START_SEQUENCE: case LONG_STOP_SEQUENCE: ics->num_windows = 1; ics->num_window_groups = 1; ics->window_group_length[ics->num_window_groups-1] = 1; #ifdef LD_DEC if (hDecoder->object_type == LD) { if (hDecoder->frameLength == 512) ics->num_swb = num_swb_512_window[sf_index]; else /* if (hDecoder->frameLength == 480) */ ics->num_swb = num_swb_480_window[sf_index]; } else { #endif if (hDecoder->frameLength == 1024) ics->num_swb = num_swb_1024_window[sf_index]; else /* if (hDecoder->frameLength == 960) */ ics->num_swb = num_swb_960_window[sf_index]; #ifdef LD_DEC } #endif /* preparation of sect_sfb_offset for long blocks */ /* also copy the last value! */ #ifdef LD_DEC if (hDecoder->object_type == LD) { if (hDecoder->frameLength == 512) { for (i = 0; i < ics->num_swb; i++) { ics->sect_sfb_offset[0][i] = swb_offset_512_window[sf_index][i]; ics->swb_offset[i] = swb_offset_512_window[sf_index][i]; } } else /* if (hDecoder->frameLength == 480) */ { for (i = 0; i < ics->num_swb; i++) { ics->sect_sfb_offset[0][i] = swb_offset_480_window[sf_index][i]; ics->swb_offset[i] = swb_offset_480_window[sf_index][i]; } } ics->sect_sfb_offset[0][ics->num_swb] = hDecoder->frameLength; ics->swb_offset[ics->num_swb] = hDecoder->frameLength; } else { #endif for (i = 0; i < ics->num_swb; i++) { ics->sect_sfb_offset[0][i] = swb_offset_1024_window[sf_index][i]; ics->swb_offset[i] = swb_offset_1024_window[sf_index][i]; } ics->sect_sfb_offset[0][ics->num_swb] = hDecoder->frameLength; ics->swb_offset[ics->num_swb] = hDecoder->frameLength; #ifdef LD_DEC } #endif return 0; case EIGHT_SHORT_SEQUENCE: ics->num_windows = 8; ics->num_window_groups = 1; ics->window_group_length[ics->num_window_groups-1] = 1; ics->num_swb = num_swb_128_window[sf_index]; for (i = 0; i < ics->num_swb; i++) ics->swb_offset[i] = swb_offset_128_window[sf_index][i]; ics->swb_offset[ics->num_swb] = hDecoder->frameLength/8; for (i = 0; i < ics->num_windows-1; i++) { if (bit_set(ics->scale_factor_grouping, 6-i) == 0) { ics->num_window_groups += 1; ics->window_group_length[ics->num_window_groups-1] = 1; } else { ics->window_group_length[ics->num_window_groups-1] += 1; } } /* preparation of sect_sfb_offset for short blocks */ for (g = 0; g < ics->num_window_groups; g++) { uint16_t width; uint8_t sect_sfb = 0; uint16_t offset = 0; for (i = 0; i < ics->num_swb; i++) { if (i+1 == ics->num_swb) { width = (hDecoder->frameLength/8) - swb_offset_128_window[sf_index][i]; } else { width = swb_offset_128_window[sf_index][i+1] - swb_offset_128_window[sf_index][i]; } width *= ics->window_group_length[g]; ics->sect_sfb_offset[g][sect_sfb++] = offset; offset += width; } ics->sect_sfb_offset[g][sect_sfb] = offset; } return 0; default: return 1; } } /* For ONLY_LONG_SEQUENCE windows (num_window_groups = 1, window_group_length[0] = 1) the spectral data is in ascending spectral order. For the EIGHT_SHORT_SEQUENCE window, the spectral order depends on the grouping in the following manner: - Groups are ordered sequentially - Within a group, a scalefactor band consists of the spectral data of all grouped SHORT_WINDOWs for the associated scalefactor window band. To clarify via example, the length of a group is in the range of one to eight SHORT_WINDOWs. - If there are eight groups each with length one (num_window_groups = 8, window_group_length[0..7] = 1), the result is a sequence of eight spectra, each in ascending spectral order. - If there is only one group with length eight (num_window_groups = 1, window_group_length[0] = 8), the result is that spectral data of all eight SHORT_WINDOWs is interleaved by scalefactor window bands. - Within a scalefactor window band, the coefficients are in ascending spectral order. */ void quant_to_spec(ic_stream *ics, real_t *spec_data, uint16_t frame_len) { uint8_t g, sfb, win; uint16_t width, bin, k, gindex; real_t tmp_spec[1024]; memset(tmp_spec, 0, frame_len*sizeof(real_t)); k = 0; gindex = 0; for (g = 0; g < ics->num_window_groups; g++) { uint16_t j = 0; uint16_t gincrease = 0; uint16_t win_inc = ics->swb_offset[ics->num_swb]; for (sfb = 0; sfb < ics->num_swb; sfb++) { width = ics->swb_offset[sfb+1] - ics->swb_offset[sfb]; for (win = 0; win < ics->window_group_length[g]; win++) { for (bin = 0; bin < width; bin += 4) { tmp_spec[gindex+(win*win_inc)+j+bin+0] = spec_data[k+0]; tmp_spec[gindex+(win*win_inc)+j+bin+1] = spec_data[k+1]; tmp_spec[gindex+(win*win_inc)+j+bin+2] = spec_data[k+2]; tmp_spec[gindex+(win*win_inc)+j+bin+3] = spec_data[k+3]; gincrease += 4; k += 4; } } j += width; } gindex += gincrease; } memcpy(spec_data, tmp_spec, frame_len*sizeof(real_t)); } #ifndef FIXED_POINT void build_tables(real_t *pow2_table) { uint16_t i; /* build pow(2, 0.25*x) table for scalefactors */ for(i = 0; i < POW_TABLE_SIZE; i++) { pow2_table[i] = REAL_CONST(pow(2.0, 0.25 * (i-100))); } } #endif static INLINE real_t iquant(int16_t q, real_t *tab) { #ifdef FIXED_POINT int16_t sgn = 1; if (q == 0) return 0; if (q < 0) { q = -q; sgn = -1; } if (q >= IQ_TABLE_SIZE) return 0; /* sgn * tab[q>>3] * 16; */ return sgn * tab[q]; #else int16_t sgn = 1; if (q == 0) return 0; if (q < 0) { q = -q; sgn = -1; } if (q < IQ_TABLE_SIZE) return sgn * tab[q]; return sgn * pow(q, 4./3.); #endif } void inverse_quantization(real_t *x_invquant, int16_t *x_quant, uint16_t frame_len) { int16_t i; real_t *tab = iq_table; for(i = 0; i < frame_len; i+=4) { x_invquant[i] = iquant(x_quant[i], tab); x_invquant[i+1] = iquant(x_quant[i+1], tab); x_invquant[i+2] = iquant(x_quant[i+2], tab); x_invquant[i+3] = iquant(x_quant[i+3], tab); } } #ifndef FIXED_POINT static INLINE real_t get_scale_factor_gain(uint16_t scale_factor, real_t *pow2_table) { if (scale_factor < POW_TABLE_SIZE) return pow2_table[scale_factor]; else return REAL_CONST(pow(2.0, 0.25 * (scale_factor - 100))); } #else static real_t pow2_table[] = { COEF_CONST(0.59460355750136), COEF_CONST(0.70710678118655), COEF_CONST(0.84089641525371), COEF_CONST(1.0), COEF_CONST(1.18920711500272), COEF_CONST(1.41421356237310), COEF_CONST(1.68179283050743) }; #endif void apply_scalefactors(faacDecHandle hDecoder, ic_stream *ics, real_t *x_invquant, uint16_t frame_len) { uint8_t g, sfb; uint16_t top; #ifndef FIXED_POINT real_t scale; #else int32_t exp, frac; #endif uint8_t groups = 0; uint16_t nshort = frame_len/8; static real_t max_fp = 0; static real_t max_exp = 0; static real_t max_frac = 0; for (g = 0; g < ics->num_window_groups; g++) { uint16_t k = 0; /* using this nshort*groups doesn't hurt long blocks, because long blocks only have 1 group, so that means 'groups' is always 0 for long blocks */ for (sfb = 0; sfb < ics->max_sfb; sfb++) { top = ics->sect_sfb_offset[g][sfb+1]; #ifndef FIXED_POINT scale = get_scale_factor_gain(ics->scale_factors[g][sfb], hDecoder->pow2_table); #else exp = (ics->scale_factors[g][sfb] - 100) / 4; frac = (ics->scale_factors[g][sfb] - 100) % 4; /* IMDCT pre-scaling */ if (hDecoder->object_type == LD) { exp -= 6 /*9*/; } else { if (ics->window_sequence == EIGHT_SHORT_SEQUENCE) exp -= 4 /*7*/; else exp -= 7 /*10*/; } #endif /* minimum size of a sf band is 4 and always a multiple of 4 */ for ( ; k < top; k += 4) { #ifndef FIXED_POINT x_invquant[k+(groups*nshort)] = x_invquant[k+(groups*nshort)] * scale; x_invquant[k+(groups*nshort)+1] = x_invquant[k+(groups*nshort)+1] * scale; x_invquant[k+(groups*nshort)+2] = x_invquant[k+(groups*nshort)+2] * scale; x_invquant[k+(groups*nshort)+3] = x_invquant[k+(groups*nshort)+3] * scale; #else if (exp < 0) { x_invquant[k+(groups*nshort)] >>= -exp; x_invquant[k+(groups*nshort)+1] >>= -exp; x_invquant[k+(groups*nshort)+2] >>= -exp; x_invquant[k+(groups*nshort)+3] >>= -exp; } else { x_invquant[k+(groups*nshort)] <<= exp; x_invquant[k+(groups*nshort)+1] <<= exp; x_invquant[k+(groups*nshort)+2] <<= exp; x_invquant[k+(groups*nshort)+3] <<= exp; } if (frac) { x_invquant[k+(groups*nshort)] = MUL_R_C(x_invquant[k+(groups*nshort)],pow2_table[frac + 3]); x_invquant[k+(groups*nshort)+1] = MUL_R_C(x_invquant[k+(groups*nshort)+1],pow2_table[frac + 3]); x_invquant[k+(groups*nshort)+2] = MUL_R_C(x_invquant[k+(groups*nshort)+2],pow2_table[frac + 3]); x_invquant[k+(groups*nshort)+3] = MUL_R_C(x_invquant[k+(groups*nshort)+3],pow2_table[frac + 3]); } #endif } } groups += ics->window_group_length[g]; } }