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| author | Michał Cichoń <michcic@gmail.com> | 2012-06-26 20:35:30 +0200 |
|---|---|---|
| committer | Michał Cichoń <michcic@gmail.com> | 2012-06-26 20:35:30 +0200 |
| commit | cc2160de5cc05dc3aa77f3a34358e66f6193c8c9 (patch) | |
| tree | b93dd2dbdf7ea5ca4d6647c58dbe504824ac419f /faad2/src/libfaad/tns.c | |
| parent | a9c5f408fdc10f9fd1da6e5cf6f6376f1f591e10 (diff) | |
| download | pianobar-windows-build-cc2160de5cc05dc3aa77f3a34358e66f6193c8c9.tar.gz pianobar-windows-build-cc2160de5cc05dc3aa77f3a34358e66f6193c8c9.tar.bz2 pianobar-windows-build-cc2160de5cc05dc3aa77f3a34358e66f6193c8c9.zip | |
Add support for AAC.
Diffstat (limited to 'faad2/src/libfaad/tns.c')
| -rw-r--r-- | faad2/src/libfaad/tns.c | 309 |
1 files changed, 309 insertions, 0 deletions
diff --git a/faad2/src/libfaad/tns.c b/faad2/src/libfaad/tns.c new file mode 100644 index 0000000..20538e3 --- /dev/null +++ b/faad2/src/libfaad/tns.c @@ -0,0 +1,309 @@ +/*
+** 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;
+ }
+}
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