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diff --git a/audio_codec/libfaad/tns.c b/audio_codec/libfaad/tns.c new file mode 100644 index 0000000..a0718eb --- a/dev/null +++ b/audio_codec/libfaad/tns.c @@ -0,0 +1,304 @@ +/* +** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding +** Copyright (C) 2003-2005 M. Bakker, Nero 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. +** +** The "appropriate copyright message" mentioned in section 2c of the GPLv2 +** must read: "Code from FAAD2 is copyright (c) Nero AG, www.nero.com" +** +** Commercial non-GPL licensing of this software is possible. +** For more info contact Nero AG through Mpeg4AAClicense@nero.com. +** +** $Id: tns.c,v 1.40 2007/11/01 12:33:40 menno Exp $ +**/ + +#include "common.h" +#include "structs.h" + +#include "syntax.h" +#include "tns.h" + + +/* static function declarations */ +static void tns_decode_coef(uint8_t order, uint8_t coef_res_bits, uint8_t coef_compress, + uint8_t *coef, real_t *a); +static void tns_ar_filter(real_t *spectrum, uint16_t size, int8_t inc, real_t *lpc, + uint8_t order); +static void tns_ma_filter(real_t *spectrum, uint16_t size, int8_t inc, real_t *lpc, + uint8_t order); + + +#ifdef _MSC_VER +#pragma warning(disable:4305) +#pragma warning(disable:4244) +#endif +static real_t tns_coef_0_3[] = { + COEF_CONST(0.0), COEF_CONST(0.4338837391), COEF_CONST(0.7818314825), COEF_CONST(0.9749279122), + COEF_CONST(-0.9848077530), COEF_CONST(-0.8660254038), COEF_CONST(-0.6427876097), COEF_CONST(-0.3420201433), + COEF_CONST(-0.4338837391), COEF_CONST(-0.7818314825), COEF_CONST(-0.9749279122), COEF_CONST(-0.9749279122), + COEF_CONST(-0.9848077530), COEF_CONST(-0.8660254038), COEF_CONST(-0.6427876097), COEF_CONST(-0.3420201433) +}; +static real_t tns_coef_0_4[] = { + COEF_CONST(0.0), COEF_CONST(0.2079116908), COEF_CONST(0.4067366431), COEF_CONST(0.5877852523), + COEF_CONST(0.7431448255), COEF_CONST(0.8660254038), COEF_CONST(0.9510565163), COEF_CONST(0.9945218954), + COEF_CONST(-0.9957341763), COEF_CONST(-0.9618256432), COEF_CONST(-0.8951632914), COEF_CONST(-0.7980172273), + COEF_CONST(-0.6736956436), COEF_CONST(-0.5264321629), COEF_CONST(-0.3612416662), COEF_CONST(-0.1837495178) +}; +static real_t tns_coef_1_3[] = { + COEF_CONST(0.0), COEF_CONST(0.4338837391), COEF_CONST(-0.6427876097), COEF_CONST(-0.3420201433), + COEF_CONST(0.9749279122), COEF_CONST(0.7818314825), COEF_CONST(-0.6427876097), COEF_CONST(-0.3420201433), + COEF_CONST(-0.4338837391), COEF_CONST(-0.7818314825), COEF_CONST(-0.6427876097), COEF_CONST(-0.3420201433), + COEF_CONST(-0.7818314825), COEF_CONST(-0.4338837391), COEF_CONST(-0.6427876097), COEF_CONST(-0.3420201433) +}; +static real_t tns_coef_1_4[] = { + COEF_CONST(0.0), COEF_CONST(0.2079116908), COEF_CONST(0.4067366431), COEF_CONST(0.5877852523), + COEF_CONST(-0.6736956436), COEF_CONST(-0.5264321629), COEF_CONST(-0.3612416662), COEF_CONST(-0.1837495178), + COEF_CONST(0.9945218954), COEF_CONST(0.9510565163), COEF_CONST(0.8660254038), COEF_CONST(0.7431448255), + COEF_CONST(-0.6736956436), COEF_CONST(-0.5264321629), COEF_CONST(-0.3612416662), COEF_CONST(-0.1837495178) +}; + + +/* TNS decoding for one channel and frame */ +void tns_decode_frame(ic_stream *ics, tns_info *tns, uint8_t sr_index, + uint8_t object_type, real_t *spec, uint16_t frame_len) +{ + uint8_t w, f, tns_order; + int8_t inc; + int16_t size; + uint16_t bottom, top, start, end; + uint16_t nshort = frame_len / 8; + real_t lpc[TNS_MAX_ORDER + 1]; + + if (!ics->tns_data_present) { + return; + } + + for (w = 0; w < ics->num_windows; w++) { + bottom = ics->num_swb; + + for (f = 0; f < tns->n_filt[w]; f++) { + top = bottom; + bottom = max(top - tns->length[w][f], 0); + tns_order = min(tns->order[w][f], TNS_MAX_ORDER); + if (!tns_order) { + continue; + } + + tns_decode_coef(tns_order, tns->coef_res[w] + 3, + tns->coef_compress[w][f], tns->coef[w][f], lpc); + + start = min(bottom, max_tns_sfb(sr_index, object_type, (ics->window_sequence == EIGHT_SHORT_SEQUENCE))); + start = min(start, ics->max_sfb); + start = min(ics->swb_offset[start], ics->swb_offset_max); + + end = min(top, max_tns_sfb(sr_index, object_type, (ics->window_sequence == EIGHT_SHORT_SEQUENCE))); + end = min(end, ics->max_sfb); + end = min(ics->swb_offset[end], ics->swb_offset_max); + + size = end - start; + if (size <= 0) { + continue; + } + + if (tns->direction[w][f]) { + inc = -1; + start = end - 1; + } else { + inc = 1; + } + + tns_ar_filter(&spec[(w * nshort) + start], size, inc, lpc, tns_order); + } + } +} + +/* TNS encoding for one channel and frame */ +void tns_encode_frame(ic_stream *ics, tns_info *tns, uint8_t sr_index, + uint8_t object_type, real_t *spec, uint16_t frame_len) +{ + uint8_t w, f, tns_order; + int8_t inc; + int16_t size; + uint16_t bottom, top, start, end; + uint16_t nshort = frame_len / 8; + real_t lpc[TNS_MAX_ORDER + 1]; + + if (!ics->tns_data_present) { + return; + } + + for (w = 0; w < ics->num_windows; w++) { + bottom = ics->num_swb; + + for (f = 0; f < tns->n_filt[w]; f++) { + top = bottom; + bottom = max(top - tns->length[w][f], 0); + tns_order = min(tns->order[w][f], TNS_MAX_ORDER); + if (!tns_order) { + continue; + } + + tns_decode_coef(tns_order, tns->coef_res[w] + 3, + tns->coef_compress[w][f], tns->coef[w][f], lpc); + + start = min(bottom, max_tns_sfb(sr_index, object_type, (ics->window_sequence == EIGHT_SHORT_SEQUENCE))); + start = min(start, ics->max_sfb); + start = min(ics->swb_offset[start], ics->swb_offset_max); + + end = min(top, max_tns_sfb(sr_index, object_type, (ics->window_sequence == EIGHT_SHORT_SEQUENCE))); + end = min(end, ics->max_sfb); + end = min(ics->swb_offset[end], ics->swb_offset_max); + + size = end - start; + if (size <= 0) { + continue; + } + + if (tns->direction[w][f]) { + inc = -1; + start = end - 1; + } else { + inc = 1; + } + + tns_ma_filter(&spec[(w * nshort) + start], size, inc, lpc, tns_order); + } + } +} + +/* Decoder transmitted coefficients for one TNS filter */ +static void tns_decode_coef(uint8_t order, uint8_t coef_res_bits, uint8_t coef_compress, + uint8_t *coef, real_t *a) +{ + uint8_t i, m; + real_t tmp2[TNS_MAX_ORDER + 1], b[TNS_MAX_ORDER + 1]; + + /* Conversion to signed integer */ + for (i = 0; i < order; i++) { + if (coef_compress == 0) { + if (coef_res_bits == 3) { + tmp2[i] = tns_coef_0_3[coef[i]]; + } else { + tmp2[i] = tns_coef_0_4[coef[i]]; + } + } else { + if (coef_res_bits == 3) { + tmp2[i] = tns_coef_1_3[coef[i]]; + } else { + tmp2[i] = tns_coef_1_4[coef[i]]; + } + } + } + + /* Conversion to LPC coefficients */ + a[0] = COEF_CONST(1.0); + for (m = 1; m <= order; m++) { + for (i = 1; i < m; i++) { /* loop only while i<m */ + b[i] = a[i] + MUL_C(tmp2[m - 1], a[m - i]); + } + + for (i = 1; i < m; i++) { /* loop only while i<m */ + a[i] = b[i]; + } + + a[m] = tmp2[m - 1]; /* changed */ + } +} + +static void tns_ar_filter(real_t *spectrum, uint16_t size, int8_t inc, real_t *lpc, + uint8_t order) +{ + /* + - Simple all-pole filter of order "order" defined by + y(n) = x(n) - lpc[1]*y(n-1) - ... - lpc[order]*y(n-order) + - The state variables of the filter are initialized to zero every time + - The output data is written over the input data ("in-place operation") + - An input vector of "size" samples is processed and the index increment + to the next data sample is given by "inc" + */ + + uint8_t j; + uint16_t i; + real_t y; + /* state is stored as a double ringbuffer */ + real_t state[2 * TNS_MAX_ORDER] = {0}; + int8_t state_index = 0; + + for (i = 0; i < size; i++) { + y = *spectrum; + + for (j = 0; j < order; j++) { + y -= MUL_C(state[state_index + j], lpc[j + 1]); + } + + /* double ringbuffer state */ + state_index--; + if (state_index < 0) { + state_index = order - 1; + } + state[state_index] = state[state_index + order] = y; + + *spectrum = y; + spectrum += inc; + + //#define TNS_PRINT +#ifdef TNS_PRINT + //printf("%d\n", y); + printf("0x%.8X\n", y); +#endif + } +} + +static void tns_ma_filter(real_t *spectrum, uint16_t size, int8_t inc, real_t *lpc, + uint8_t order) +{ + /* + - Simple all-zero filter of order "order" defined by + y(n) = x(n) + a(2)*x(n-1) + ... + a(order+1)*x(n-order) + - The state variables of the filter are initialized to zero every time + - The output data is written over the input data ("in-place operation") + - An input vector of "size" samples is processed and the index increment + to the next data sample is given by "inc" + */ + + uint8_t j; + uint16_t i; + real_t y; + /* state is stored as a double ringbuffer */ + real_t state[2 * TNS_MAX_ORDER] = {0}; + int8_t state_index = 0; + + for (i = 0; i < size; i++) { + y = *spectrum; + + for (j = 0; j < order; j++) { + y += MUL_C(state[state_index + j], lpc[j + 1]); + } + + /* double ringbuffer state */ + state_index--; + if (state_index < 0) { + state_index = order - 1; + } + state[state_index] = state[state_index + order] = *spectrum; + + *spectrum = y; + spectrum += inc; + } +} |