mirror of
https://github.com/mpv-player/mpv
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32063c4339
git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@10726 b3059339-0415-0410-9bf9-f77b7e298cf2
197 lines
5.3 KiB
C
197 lines
5.3 KiB
C
/*
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** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
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** Copyright (C) 2003 M. Bakker, Ahead Software AG, http://www.nero.com
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**
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** This program is free software; you can redistribute it and/or modify
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** it under the terms of the GNU General Public License as published by
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** the Free Software Foundation; either version 2 of the License, or
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** (at your option) any later version.
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**
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** This program is distributed in the hope that it will be useful,
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** but WITHOUT ANY WARRANTY; without even the implied warranty of
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** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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** GNU General Public License for more details.
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**
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** You should have received a copy of the GNU General Public License
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** along with this program; if not, write to the Free Software
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** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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**
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** Any non-GPL usage of this software or parts of this software is strictly
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** forbidden.
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**
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** Commercial non-GPL licensing of this software is possible.
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** For more info contact Ahead Software through Mpeg4AAClicense@nero.com.
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**
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** $Id: ic_predict.c,v 1.12 2003/07/29 08:20:12 menno Exp $
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**/
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#include "common.h"
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#include "structs.h"
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#ifdef MAIN_DEC
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#include "syntax.h"
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#include "ic_predict.h"
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#include "pns.h"
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static void flt_round(real_t *pf)
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{
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/* more stable version for clever compilers like gcc 3.x */
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int32_t flg;
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uint32_t tmp, tmp1, tmp2;
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tmp = *(uint32_t*)pf;
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flg = tmp & (uint32_t)0x00008000;
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tmp &= (uint32_t)0xffff0000;
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tmp1 = tmp;
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/* round 1/2 lsb toward infinity */
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if (flg)
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{
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tmp &= (uint32_t)0xff800000; /* extract exponent and sign */
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tmp |= (uint32_t)0x00010000; /* insert 1 lsb */
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tmp2 = tmp; /* add 1 lsb and elided one */
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tmp &= (uint32_t)0xff800000; /* extract exponent and sign */
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*pf = *(real_t*)&tmp1+*(real_t*)&tmp2-*(real_t*)&tmp;/* subtract elided one */
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} else {
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*pf = *(real_t*)&tmp;
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}
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}
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static void ic_predict(pred_state *state, real_t input, real_t *output, uint8_t pred)
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{
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real_t dr1, predictedvalue;
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real_t e0, e1;
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real_t k1, k2;
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real_t *r;
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real_t *KOR;
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real_t *VAR;
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r = state->r; /* delay elements */
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KOR = state->KOR; /* correlations */
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VAR = state->VAR; /* variances */
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if (VAR[0] <= 1)
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k1 = 0;
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else
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k1 = KOR[0]/VAR[0]*B;
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if (pred)
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{
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/* only needed for the actual predicted value, k1 is always needed */
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if (VAR[1] <= 1)
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k2 = 0;
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else
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k2 = KOR[1]/VAR[1]*B;
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predictedvalue = MUL(k1, r[0]) + MUL(k2, r[1]);
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flt_round(&predictedvalue);
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*output = input + predictedvalue;
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} else {
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*output = input;
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}
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/* calculate new state data */
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e0 = *output;
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e1 = e0 - MUL(k1, r[0]);
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dr1 = MUL(k1, e0);
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VAR[0] = MUL(ALPHA, VAR[0]) + MUL(REAL_CONST(0.5), (MUL(r[0], r[0]) + MUL(e0, e0)));
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KOR[0] = MUL(ALPHA, KOR[0]) + MUL(r[0], e0);
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VAR[1] = MUL(ALPHA, VAR[1]) + MUL(REAL_CONST(0.5), (MUL(r[1], r[1]) + MUL(e1, e1)));
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KOR[1] = MUL(ALPHA, KOR[1]) + MUL(r[1], e1);
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r[1] = MUL(A, (r[0]-dr1));
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r[0] = MUL(A, e0);
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}
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static void reset_pred_state(pred_state *state)
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{
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state->r[0] = 0;
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state->r[1] = 0;
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state->KOR[0] = 0;
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state->KOR[1] = 0;
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state->VAR[0] = REAL_CONST(1.0);
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state->VAR[1] = REAL_CONST(1.0);
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}
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void pns_reset_pred_state(ic_stream *ics, pred_state *state)
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{
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uint8_t sfb, g, b;
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uint16_t i, offs, offs2;
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/* prediction only for long blocks */
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if (ics->window_sequence == EIGHT_SHORT_SEQUENCE)
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return;
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for (g = 0; g < ics->num_window_groups; g++)
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{
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for (b = 0; b < ics->window_group_length[g]; b++)
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{
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for (sfb = 0; sfb < ics->max_sfb; sfb++)
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{
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if (is_noise(ics, g, sfb))
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{
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offs = ics->swb_offset[sfb];
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offs2 = ics->swb_offset[sfb+1];
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for (i = offs; i < offs2; i++)
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reset_pred_state(&state[i]);
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}
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}
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}
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}
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}
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void reset_all_predictors(pred_state *state, uint16_t frame_len)
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{
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uint16_t i;
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for (i = 0; i < frame_len; i++)
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reset_pred_state(&state[i]);
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}
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/* intra channel prediction */
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void ic_prediction(ic_stream *ics, real_t *spec, pred_state *state,
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uint16_t frame_len)
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{
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uint8_t sfb;
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uint16_t bin;
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if (ics->window_sequence == EIGHT_SHORT_SEQUENCE)
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{
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reset_all_predictors(state, frame_len);
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} else {
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for (sfb = 0; sfb < ics->pred.limit; sfb++)
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{
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uint16_t low = ics->swb_offset[sfb];
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uint16_t high = ics->swb_offset[sfb+1];
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for (bin = low; bin < high; bin++)
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{
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ic_predict(&state[bin], spec[bin], &spec[bin],
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(ics->predictor_data_present &&
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ics->pred.prediction_used[sfb]));
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}
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}
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if (ics->predictor_data_present)
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{
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if (ics->pred.predictor_reset)
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{
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for (bin = ics->pred.predictor_reset_group_number - 1;
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bin < frame_len; bin += 30)
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{
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reset_pred_state(&state[bin]);
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}
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}
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}
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}
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}
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#endif
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