Initial check-in of unmodified libfaad (part of the FAAD2 project). This is the last version of libfaad available under the GPL - the state of FAAD2 CVS at midnight on 2005-02-01

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@7699 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 306 insertions, 0 deletions

diff --git a/apps/codecs/libfaad/tns.c b/apps/codecs/libfaad/tns.c
new file mode 100644
index 0000000000..fa33e57a14
--- /dev/null
+++ b/apps/codecs/libfaad/tns.c
@@ -0,0 +1,306 @@
+/*
+** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
+** Copyright (C) 2003-2004 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.
+**
+** $Id$
+**/
+
+#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 = ics->swb_offset[start];
+
+            end = min(top, max_tns_sfb(sr_index, object_type, (ics->window_sequence == EIGHT_SHORT_SEQUENCE)));
+            end = min(end, ics->max_sfb);
+            end = ics->swb_offset[end];
+
+            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 = ics->swb_offset[start];
+
+            end = min(top, max_tns_sfb(sr_index, object_type, (ics->window_sequence == EIGHT_SHORT_SEQUENCE)));
+            end = min(end, ics->max_sfb);
+            end = ics->swb_offset[end];
+
+            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[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;
+    }
+}