From cc2160de5cc05dc3aa77f3a34358e66f6193c8c9 Mon Sep 17 00:00:00 2001 From: Michał Cichoń Date: Tue, 26 Jun 2012 20:35:30 +0200 Subject: Add support for AAC. --- faad2/src/libfaad/ic_predict.c | 271 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 271 insertions(+) create mode 100644 faad2/src/libfaad/ic_predict.c (limited to 'faad2/src/libfaad/ic_predict.c') diff --git a/faad2/src/libfaad/ic_predict.c b/faad2/src/libfaad/ic_predict.c new file mode 100644 index 0000000..f9e51bd --- /dev/null +++ b/faad2/src/libfaad/ic_predict.c @@ -0,0 +1,271 @@ +/* +** 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: ic_predict.c,v 1.28 2007/11/01 12:33:31 menno Exp $ +**/ + +#include "common.h" +#include "structs.h" + +#ifdef MAIN_DEC + +#include "syntax.h" +#include "ic_predict.h" +#include "pns.h" + + +static void flt_round(float32_t *pf) +{ + int32_t flg; + uint32_t tmp, tmp1, tmp2; + + tmp = *(uint32_t*)pf; + flg = tmp & (uint32_t)0x00008000; + tmp &= (uint32_t)0xffff0000; + tmp1 = tmp; + /* round 1/2 lsb toward infinity */ + if (flg) + { + tmp &= (uint32_t)0xff800000; /* extract exponent and sign */ + tmp |= (uint32_t)0x00010000; /* insert 1 lsb */ + tmp2 = tmp; /* add 1 lsb and elided one */ + tmp &= (uint32_t)0xff800000; /* extract exponent and sign */ + + *pf = *(float32_t*)&tmp1 + *(float32_t*)&tmp2 - *(float32_t*)&tmp; + } else { + *pf = *(float32_t*)&tmp; + } +} + +static int16_t quant_pred(float32_t x) +{ + int16_t q; + uint32_t *tmp = (uint32_t*)&x; + + q = (int16_t)(*tmp>>16); + + return q; +} + +static float32_t inv_quant_pred(int16_t q) +{ + float32_t x; + uint32_t *tmp = (uint32_t*)&x; + *tmp = ((uint32_t)q)<<16; + + return x; +} + +static void ic_predict(pred_state *state, real_t input, real_t *output, uint8_t pred) +{ + uint16_t tmp; + int16_t i, j; + real_t dr1; + float32_t predictedvalue; + real_t e0, e1; + real_t k1, k2; + + real_t r[2]; + real_t COR[2]; + real_t VAR[2]; + + r[0] = inv_quant_pred(state->r[0]); + r[1] = inv_quant_pred(state->r[1]); + COR[0] = inv_quant_pred(state->COR[0]); + COR[1] = inv_quant_pred(state->COR[1]); + VAR[0] = inv_quant_pred(state->VAR[0]); + VAR[1] = inv_quant_pred(state->VAR[1]); + + +#if 1 + tmp = state->VAR[0]; + j = (tmp >> 7); + i = tmp & 0x7f; + if (j >= 128) + { + j -= 128; + k1 = COR[0] * exp_table[j] * mnt_table[i]; + } else { + k1 = REAL_CONST(0); + } +#else + + { +#define B 0.953125 + real_t c = COR[0]; + real_t v = VAR[0]; + float32_t tmp; + if (c == 0 || v <= 1) + { + k1 = 0; + } else { + tmp = B / v; + flt_round(&tmp); + k1 = c * tmp; + } + } +#endif + + if (pred) + { +#if 1 + tmp = state->VAR[1]; + j = (tmp >> 7); + i = tmp & 0x7f; + if (j >= 128) + { + j -= 128; + k2 = COR[1] * exp_table[j] * mnt_table[i]; + } else { + k2 = REAL_CONST(0); + } +#else + +#define B 0.953125 + real_t c = COR[1]; + real_t v = VAR[1]; + float32_t tmp; + if (c == 0 || v <= 1) + { + k2 = 0; + } else { + tmp = B / v; + flt_round(&tmp); + k2 = c * tmp; + } +#endif + + predictedvalue = k1*r[0] + k2*r[1]; + flt_round(&predictedvalue); + *output = input + predictedvalue; + } + + /* calculate new state data */ + e0 = *output; + e1 = e0 - k1*r[0]; + dr1 = k1*e0; + + VAR[0] = ALPHA*VAR[0] + 0.5f * (r[0]*r[0] + e0*e0); + COR[0] = ALPHA*COR[0] + r[0]*e0; + VAR[1] = ALPHA*VAR[1] + 0.5f * (r[1]*r[1] + e1*e1); + COR[1] = ALPHA*COR[1] + r[1]*e1; + + r[1] = A * (r[0]-dr1); + r[0] = A * e0; + + state->r[0] = quant_pred(r[0]); + state->r[1] = quant_pred(r[1]); + state->COR[0] = quant_pred(COR[0]); + state->COR[1] = quant_pred(COR[1]); + state->VAR[0] = quant_pred(VAR[0]); + state->VAR[1] = quant_pred(VAR[1]); +} + +static void reset_pred_state(pred_state *state) +{ + state->r[0] = 0; + state->r[1] = 0; + state->COR[0] = 0; + state->COR[1] = 0; + state->VAR[0] = 0x3F80; + state->VAR[1] = 0x3F80; +} + +void pns_reset_pred_state(ic_stream *ics, pred_state *state) +{ + uint8_t sfb, g, b; + uint16_t i, offs, offs2; + + /* prediction only for long blocks */ + if (ics->window_sequence == EIGHT_SHORT_SEQUENCE) + return; + + for (g = 0; g < ics->num_window_groups; g++) + { + for (b = 0; b < ics->window_group_length[g]; b++) + { + for (sfb = 0; sfb < ics->max_sfb; sfb++) + { + if (is_noise(ics, g, sfb)) + { + offs = ics->swb_offset[sfb]; + offs2 = min(ics->swb_offset[sfb+1], ics->swb_offset_max); + + for (i = offs; i < offs2; i++) + reset_pred_state(&state[i]); + } + } + } + } +} + +void reset_all_predictors(pred_state *state, uint16_t frame_len) +{ + uint16_t i; + + for (i = 0; i < frame_len; i++) + reset_pred_state(&state[i]); +} + +/* intra channel prediction */ +void ic_prediction(ic_stream *ics, real_t *spec, pred_state *state, + uint16_t frame_len, uint8_t sf_index) +{ + uint8_t sfb; + uint16_t bin; + + if (ics->window_sequence == EIGHT_SHORT_SEQUENCE) + { + reset_all_predictors(state, frame_len); + } else { + for (sfb = 0; sfb < max_pred_sfb(sf_index); sfb++) + { + uint16_t low = ics->swb_offset[sfb]; + uint16_t high = min(ics->swb_offset[sfb+1], ics->swb_offset_max); + + for (bin = low; bin < high; bin++) + { + ic_predict(&state[bin], spec[bin], &spec[bin], + (ics->predictor_data_present && ics->pred.prediction_used[sfb])); + } + } + + if (ics->predictor_data_present) + { + if (ics->pred.predictor_reset) + { + for (bin = ics->pred.predictor_reset_group_number - 1; + bin < frame_len; bin += 30) + { + reset_pred_state(&state[bin]); + } + } + } + } +} + +#endif -- cgit v1.2.3