diff options
Diffstat (limited to 'libfaad2/specrec.c')
-rw-r--r-- | libfaad2/specrec.c | 626 |
1 files changed, 626 insertions, 0 deletions
diff --git a/libfaad2/specrec.c b/libfaad2/specrec.c new file mode 100644 index 0000000000..8f3b8e6d9f --- /dev/null +++ b/libfaad2/specrec.c @@ -0,0 +1,626 @@ +/* +** 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 1.23 2003/07/29 08:20:13 menno Exp $ +**/ + +/* + Spectral reconstruction: + - grouping/sectioning + - inverse quantization + - applying scalefactors +*/ + +#include "common.h" +#include "structs.h" + +#include <string.h> +#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; + real_t *start_inptr, *start_win_ptr, *win_ptr; + + real_t tmp_spec[1024]; + real_t *tmp_spec_ptr, *spec_ptr; + + tmp_spec_ptr = tmp_spec; + memset(tmp_spec_ptr, 0, frame_len*sizeof(real_t)); + + spec_ptr = spec_data; + tmp_spec_ptr = tmp_spec; + start_win_ptr = tmp_spec_ptr; + + for (g = 0; g < ics->num_window_groups; g++) + { + uint16_t j = 0; + uint16_t win_inc = 0; + + start_inptr = spec_ptr; + + 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]; + + win_ptr = start_win_ptr; + + for (win = 0; win < ics->window_group_length[g]; win++) + { + tmp_spec_ptr = win_ptr + j; + + for (bin = 0; bin < width; bin += 4) + { + tmp_spec_ptr[0] = spec_ptr[0]; + tmp_spec_ptr[1] = spec_ptr[1]; + tmp_spec_ptr[2] = spec_ptr[2]; + tmp_spec_ptr[3] = spec_ptr[3]; + tmp_spec_ptr += 4; + spec_ptr += 4; + } + + win_ptr += win_inc; + } + j += width; + } + start_win_ptr += (spec_ptr - start_inptr); + } + + spec_ptr = spec_data; + tmp_spec_ptr = tmp_spec; + + memcpy(spec_ptr, tmp_spec_ptr, 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) +{ + 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>>3] * 16; + + return sgn * tab[q]; +} + +void inverse_quantization(real_t *x_invquant, int16_t *x_quant, uint16_t frame_len) +{ + int16_t i; + int16_t *in_ptr = x_quant; + real_t *out_ptr = x_invquant; + real_t *tab = iq_table; + + for(i = frame_len/4-1; i >= 0; --i) + { + out_ptr[0] = iquant(in_ptr[0], tab); + out_ptr[1] = iquant(in_ptr[1], tab); + out_ptr[2] = iquant(in_ptr[2], tab); + out_ptr[3] = iquant(in_ptr[3], tab); + out_ptr += 4; + in_ptr += 4; + } +} + +#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 + +#ifdef FIXED_POINT +void apply_scalefactors(faacDecHandle hDecoder, ic_stream *ics, real_t *x_invquant, + uint16_t frame_len) +#else +void apply_scalefactors(ic_stream *ics, real_t *x_invquant, real_t *pow2_table, + uint16_t frame_len) +#endif +{ + uint8_t g, sfb; + uint16_t top; + real_t *fp; +#ifndef FIXED_POINT + real_t scale; +#else + int32_t exp, frac; +#endif + uint8_t groups = 0; + uint16_t nshort = frame_len/8; + + for (g = 0; g < ics->num_window_groups; g++) + { + uint16_t k = 0; + + /* using this 128*groups doesn't hurt long blocks, because + long blocks only have 1 group, so that means 'groups' is + always 0 for long blocks + */ + fp = x_invquant + (groups*nshort); + + 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], pow2_table); +#else + exp = (ics->scale_factors[g][sfb] - 100) / 4; + frac = (ics->scale_factors[g][sfb] - 100) % 4; + + 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 + fp[0] = fp[0] * scale; + fp[1] = fp[1] * scale; + fp[2] = fp[2] * scale; + fp[3] = fp[3] * scale; +#else + if (exp < 0) + { + fp[0] >>= -exp; + fp[1] >>= -exp; + fp[2] >>= -exp; + fp[3] >>= -exp; + } else { + fp[0] <<= exp; + fp[1] <<= exp; + fp[2] <<= exp; + fp[3] <<= exp; + } + + if (frac) + { + fp[0] = MUL_R_C(fp[0],pow2_table[frac + 3]); + fp[1] = MUL_R_C(fp[1],pow2_table[frac + 3]); + fp[2] = MUL_R_C(fp[2],pow2_table[frac + 3]); + fp[3] = MUL_R_C(fp[3],pow2_table[frac + 3]); + } +#endif + fp += 4; + } + } + groups += ics->window_group_length[g]; + } +} |