From 32063c433915b8dddd143a951ad90ae901ac1b38 Mon Sep 17 00:00:00 2001 From: arpi Date: Sat, 30 Aug 2003 22:30:28 +0000 Subject: libfaad2 v2.0rc1 imported git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@10726 b3059339-0415-0410-9bf9-f77b7e298cf2 --- libfaad2/lt_predict.c | 146 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 146 insertions(+) create mode 100644 libfaad2/lt_predict.c (limited to 'libfaad2/lt_predict.c') diff --git a/libfaad2/lt_predict.c b/libfaad2/lt_predict.c new file mode 100644 index 0000000000..9393201cdf --- /dev/null +++ b/libfaad2/lt_predict.c @@ -0,0 +1,146 @@ +/* +** 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: lt_predict.c,v 1.11 2003/07/29 08:20:12 menno Exp $ +**/ + +#include "common.h" +#include "structs.h" + +#ifdef LTP_DEC + +#include +#include "syntax.h" +#include "lt_predict.h" +#include "filtbank.h" +#include "tns.h" + +static real_t codebook[8] = +{ + COEF_CONST(0.570829), + COEF_CONST(0.696616), + COEF_CONST(0.813004), + COEF_CONST(0.911304), + COEF_CONST(0.984900), + COEF_CONST(1.067894), + COEF_CONST(1.194601), + COEF_CONST(1.369533) +}; + +void lt_prediction(ic_stream *ics, ltp_info *ltp, real_t *spec, + real_t *lt_pred_stat, fb_info *fb, uint8_t win_shape, + uint8_t win_shape_prev, uint8_t sr_index, + uint8_t object_type, uint16_t frame_len) +{ + uint8_t sfb; + uint16_t bin, i, num_samples; + real_t *x_est; + real_t *X_est; + + if (ics->window_sequence != EIGHT_SHORT_SEQUENCE) + { + if (ltp->data_present) + { + num_samples = frame_len << 1; + + x_est = (real_t*)malloc(num_samples*sizeof(real_t)); + X_est = (real_t*)malloc(num_samples*sizeof(real_t)); + + for(i = 0; i < num_samples; i++) + { + /* The extra lookback M (N/2 for LD, 0 for LTP) is handled + in the buffer updating */ + x_est[i] = MUL_R_C(lt_pred_stat[num_samples + i - ltp->lag], + codebook[ltp->coef]); + } + + filter_bank_ltp(fb, ics->window_sequence, win_shape, win_shape_prev, + x_est, X_est, object_type, frame_len); + + tns_encode_frame(ics, &(ics->tns), sr_index, object_type, X_est, + frame_len); + + for (sfb = 0; sfb < ltp->last_band; sfb++) + { + if (ltp->long_used[sfb]) + { + uint16_t low = ics->swb_offset[sfb]; + uint16_t high = ics->swb_offset[sfb+1]; + + for (bin = low; bin < high; bin++) + { + spec[bin] += X_est[bin]; + } + } + } + + free(x_est); + free(X_est); + } + } +} + +void lt_update_state(real_t *lt_pred_stat, real_t *time, real_t *overlap, + uint16_t frame_len, uint8_t object_type) +{ + uint16_t i; + + /* + * The reference point for index i and the content of the buffer + * lt_pred_stat are arranged so that lt_pred_stat(0 ... N/2 - 1) contains the + * last aliased half window from the IMDCT, and lt_pred_stat(N/2 ... N-1) + * is always all zeros. The rest of lt_pred_stat (i<0) contains the previous + * fully reconstructed time domain samples, i.e., output of the decoder. + * + * These values are shifted up by N*2 to avoid (i<0) + * + * For the LD object type an extra 512 samples lookback is accomodated here. + */ +#ifdef LD_DEC + if (object_type == LD) + { + for (i = 0; i < frame_len; i++) + { + lt_pred_stat[i] /* extra 512 */ = lt_pred_stat[i + frame_len]; + lt_pred_stat[frame_len + i] = lt_pred_stat[i + (frame_len * 2)]; + lt_pred_stat[(frame_len * 2) + i] = time[i]; + lt_pred_stat[(frame_len * 3) + i] = overlap[i]; + } + } else { +#endif + for (i = 0; i < frame_len; i++) + { + lt_pred_stat[i] = lt_pred_stat[i + frame_len]; + lt_pred_stat[frame_len + i] = time[i]; + lt_pred_stat[(frame_len * 2) + i] = overlap[i]; +#if 0 /* set to zero once upon initialisation */ + lt_pred_stat[(frame_len * 3) + i] = 0; +#endif + } +#ifdef LD_DEC + } +#endif +} + +#endif -- cgit v1.2.3