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-rw-r--r--libfaad2/tns.c303
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diff --git a/libfaad2/tns.c b/libfaad2/tns.c
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+++ b/libfaad2/tns.c
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+/*
+** 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: tns.c,v 1.21 2003/07/29 08:20:14 menno Exp $
+**/
+
+#include "common.h"
+#include "structs.h"
+
+#include "syntax.h"
+#include "tns.h"
+
+#ifdef FIXED_POINT
+static real_t tns_coef_0_3[] =
+{
+ 0x0, 0x6F13013, 0xC8261BA, 0xF994E02,
+ 0xF03E3A3A, 0xF224C28C, 0xF5B72457, 0xFA8715E3,
+ 0xF90ECFED, 0xF37D9E46, 0xF066B1FE, 0xF066B1FE,
+ 0xF03E3A3A, 0xF224C28C, 0xF5B72457, 0xFA8715E3
+};
+static real_t tns_coef_0_4[] =
+{
+ 0x0, 0x3539B35, 0x681FE48, 0x9679182,
+ 0xBE3EBD4, 0xDDB3D74, 0xF378709, 0xFE98FCA,
+ 0xF011790B, 0xF09C5CB7, 0xF1AD6942, 0xF33B524A,
+ 0xF5388AEB, 0xF793BBDF, 0xFA385AA9, 0xFD0F5CAB
+};
+static real_t tns_coef_1_3[] =
+{
+ 0x0, 0x6F13013, 0xF5B72457, 0xFA8715E3,
+ 0xF994E02, 0xC8261BA, 0xF5B72457, 0xFA8715E3,
+ 0xF90ECFED, 0xF37D9E46, 0xF5B72457, 0xFA8715E3,
+ 0xF37D9E46, 0xF90ECFED, 0xF5B72457, 0xFA8715E3
+};
+static real_t tns_coef_1_4[] =
+{
+ 0x0, 0x3539B35, 0x681FE48, 0x9679182,
+ 0xF5388AEB, 0xF793BBDF, 0xFA385AA9, 0xFD0F5CAB,
+ 0xFE98FCA, 0xF378709, 0xDDB3D74, 0xBE3EBD4,
+ 0xF5388AEB, 0xF793BBDF, 0xFA385AA9, 0xFD0F5CAB
+};
+#else
+#ifdef _MSC_VER
+#pragma warning(disable:4305)
+#pragma warning(disable:4244)
+#endif
+static real_t tns_coef_0_3[] =
+{
+ 0.0, 0.4338837391, 0.7818314825, 0.9749279122,
+ -0.9848077530, -0.8660254038, -0.6427876097, -0.3420201433,
+ -0.4338837391, -0.7818314825, -0.9749279122, -0.9749279122,
+ -0.9848077530, -0.8660254038, -0.6427876097, -0.3420201433
+};
+static real_t tns_coef_0_4[] =
+{
+ 0.0, 0.2079116908, 0.4067366431, 0.5877852523,
+ 0.7431448255, 0.8660254038, 0.9510565163, 0.9945218954,
+ -0.9957341763, -0.9618256432, -0.8951632914, -0.7980172273,
+ -0.6736956436, -0.5264321629, -0.3612416662, -0.1837495178
+};
+static real_t tns_coef_1_3[] =
+{
+ 0.0, 0.4338837391, -0.6427876097, -0.3420201433,
+ 0.9749279122, 0.7818314825, -0.6427876097, -0.3420201433,
+ -0.4338837391, -0.7818314825, -0.6427876097, -0.3420201433,
+ -0.7818314825, -0.4338837391, -0.6427876097, -0.3420201433
+};
+static real_t tns_coef_1_4[] =
+{
+ 0.0, 0.2079116908, 0.4067366431, 0.5877852523,
+ -0.6736956436, -0.5264321629, -0.3612416662, -0.1837495178,
+ 0.9945218954, 0.9510565163, 0.8660254038, 0.7431448255,
+ -0.6736956436, -0.5264321629, -0.3612416662, -0.1837495178
+};
+#endif
+
+
+/* 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;
+ uint16_t bottom, top, start, end, size;
+ 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 = ics->swb_offset[min(bottom, ics->max_sfb)];
+ end = ics->swb_offset[min(top, ics->max_sfb)];
+
+ if ((size = end - start) <= 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;
+ uint16_t bottom, top, start, end, size;
+ 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 = ics->swb_offset[min(bottom, ics->max_sfb)];
+ end = ics->swb_offset[min(top, ics->max_sfb)];
+
+ if ((size = end - start) <= 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_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[TNS_MAX_ORDER];
+
+ for (i = 0; i < order; i++)
+ state[i] = 0;
+
+ for (i = 0; i < size; i++)
+ {
+ y = *spectrum;
+
+ for (j = 0; j < order; j++)
+ y -= MUL_R_C(state[j], lpc[j+1]);
+
+ for (j = order-1; j > 0; j--)
+ state[j] = state[j-1];
+
+ state[0] = y;
+ *spectrum = y;
+ spectrum += inc;
+ }
+}
+
+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[TNS_MAX_ORDER];
+
+ for (i = 0; i < order; i++)
+ state[i] = REAL_CONST(0.0);
+
+ for (i = 0; i < size; i++)
+ {
+ y = *spectrum;
+
+ for (j = 0; j < order; j++)
+ y += MUL_R_C(state[j], lpc[j+1]);
+
+ for (j = order-1; j > 0; j--)
+ state[j] = state[j-1];
+
+ state[0] = *spectrum;
+ *spectrum = y;
+ spectrum += inc;
+ }
+}
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