1 files changed, 263 insertions, 0 deletions

diff --git a/lib/rbcodec/codecs/libfaad/pns.c b/lib/rbcodec/codecs/libfaad/pns.c
new file mode 100644
index 0000000000..b75cf9f1ed
--- /dev/null
+++ b/lib/rbcodec/codecs/libfaad/pns.c
@@ -0,0 +1,263 @@
+/*
+** 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 "pns.h"
+
+
+/* static function declarations */
+static void gen_rand_vector(real_t *spec, int16_t scale_factor, uint16_t size,
+                            uint8_t sub);
+
+
+#ifdef FIXED_POINT
+
+#define step(shift) \
+    if ((0x40000000l >> shift) + root <= value)       \
+    {                                                 \
+        value -= (0x40000000l >> shift) + root;       \
+        root = (root >> 1) | (0x40000000l >> shift);  \
+    } else {                                          \
+        root = root >> 1;                             \
+    }
+
+/* fixed point square root approximation */
+/* !!!! ONLY WORKS FOR EVEN %REAL_BITS% !!!! */
+static real_t fp_sqrt(real_t value)
+{
+    real_t root = 0;
+
+    step( 0); step( 2); step( 4); step( 6);
+    step( 8); step(10); step(12); step(14);
+    step(16); step(18); step(20); step(22);
+    step(24); step(26); step(28); step(30);
+
+    if (root < value)
+        ++root;
+
+    root <<= (REAL_BITS/2);
+
+    return root;
+}
+
+static real_t pow2_table[] =
+{
+    COEF_CONST(1.0),
+    COEF_CONST(1.18920711500272),
+    COEF_CONST(1.41421356237310),
+    COEF_CONST(1.68179283050743)
+};
+#endif
+
+/* The function gen_rand_vector(addr, size) generates a vector of length
+   <size> with signed random values of average energy MEAN_NRG per random
+   value. A suitable random number generator can be realized using one
+   multiplication/accumulation per random value.
+*/
+static INLINE void gen_rand_vector(real_t *spec, int16_t scale_factor, uint16_t size,
+                                   uint8_t sub)
+{
+#ifndef FIXED_POINT
+    uint16_t i;
+    real_t energy = 0.0;
+
+    real_t scale = (real_t)1.0/(real_t)size;
+
+    for (i = 0; i < size; i++)
+    {
+        real_t tmp = scale*(real_t)(int32_t)random_int();
+        spec[i] = tmp;
+        energy += tmp*tmp;
+    }
+
+    scale = (real_t)1.0/(real_t)sqrt(energy);
+    scale *= (real_t)pow(2.0, 0.25 * scale_factor);
+    for (i = 0; i < size; i++)
+    {
+        spec[i] *= scale;
+    }
+#else
+    uint16_t i;
+    real_t energy = 0, scale;
+    int32_t exp, frac;
+
+    for (i = 0; i < size; i++)
+    {
+        /* this can be replaced by a 16 bit random generator!!!! */
+        real_t tmp = (int32_t)random_int();
+        if (tmp < 0)
+            tmp = -(tmp & ((1<<(REAL_BITS-1))-1));
+        else
+            tmp = (tmp & ((1<<(REAL_BITS-1))-1));
+
+        energy += MUL_R(tmp,tmp);
+
+        spec[i] = tmp;
+    }
+
+    energy = fp_sqrt(energy);
+    if (energy > 0)
+    {
+        scale = DIV_R(REAL_CONST(1), energy);
+
+        exp = scale_factor >> 2;
+        frac = scale_factor & 3;
+
+        /* IMDCT pre-scaling */
+        exp -= sub;
+
+        if (exp < 0)
+            scale >>= -exp;
+        else
+            scale <<= exp;
+
+        if (frac)
+            scale = MUL_C(scale, pow2_table[frac]);
+
+        for (i = 0; i < size; i++)
+        {
+            spec[i] = MUL_R(spec[i], scale);
+        }
+    }
+#endif
+}
+
+void pns_decode(ic_stream *ics_left, ic_stream *ics_right,
+                real_t *spec_left, real_t *spec_right, uint16_t frame_len,
+                uint8_t channel_pair, uint8_t object_type)
+{
+    uint8_t g, sfb, b;
+    uint16_t size, offs;
+
+    uint8_t group = 0;
+    uint16_t nshort = frame_len >> 3;
+
+    uint8_t sub = 0;
+
+#ifdef FIXED_POINT
+    /* IMDCT scaling */
+    if (object_type == LD)
+    {
+        sub = 9 /*9*/;
+    } else {
+        if (ics_left->window_sequence == EIGHT_SHORT_SEQUENCE)
+            sub = 7 /*7*/;
+        else
+            sub = 10 /*10*/;
+    }
+#endif
+
+    for (g = 0; g < ics_left->num_window_groups; g++)
+    {
+        /* Do perceptual noise substitution decoding */
+        for (b = 0; b < ics_left->window_group_length[g]; b++)
+        {
+            for (sfb = 0; sfb < ics_left->max_sfb; sfb++)
+            {
+                if (is_noise(ics_left, g, sfb))
+                {
+#ifdef LTP_DEC
+                    /* Simultaneous use of LTP and PNS is not prevented in the
+                       syntax. If both LTP, and PNS are enabled on the same
+                       scalefactor band, PNS takes precedence, and no prediction
+                       is applied to this band.
+                    */
+                    ics_left->ltp.long_used[sfb] = 0;
+                    ics_left->ltp2.long_used[sfb] = 0;
+#endif
+
+#ifdef MAIN_DEC
+                    /* For scalefactor bands coded using PNS the corresponding
+                       predictors are switched to "off".
+                    */
+                    ics_left->pred.prediction_used[sfb] = 0;
+#endif
+
+                    offs = ics_left->swb_offset[sfb];
+                    size = ics_left->swb_offset[sfb+1] - offs;
+
+                    /* Generate random vector */
+                    gen_rand_vector(&spec_left[(group*nshort)+offs],
+                        ics_left->scale_factors[g][sfb], size, sub);
+                }
+
+/* From the spec:
+   If the same scalefactor band and group is coded by perceptual noise
+   substitution in both channels of a channel pair, the correlation of
+   the noise signal can be controlled by means of the ms_used field: While
+   the default noise generation process works independently for each channel
+   (separate generation of random vectors), the same random vector is used
+   for both channels if ms_used[] is set for a particular scalefactor band
+   and group. In this case, no M/S stereo coding is carried out (because M/S
+   stereo coding and noise substitution coding are mutually exclusive).
+   If the same scalefactor band and group is coded by perceptual noise
+   substitution in only one channel of a channel pair the setting of ms_used[]
+   is not evaluated.
+*/
+                if (channel_pair)
+                {
+                    if (is_noise(ics_right, g, sfb))
+                    {
+                        if (((ics_left->ms_mask_present == 1) &&
+                            (ics_left->ms_used[g][sfb])) ||
+                            (ics_left->ms_mask_present == 2))
+                        {
+                            uint16_t c;
+
+                            offs = ics_right->swb_offset[sfb];
+                            size = ics_right->swb_offset[sfb+1] - offs;
+
+                            for (c = 0; c < size; c++)
+                            {
+                                spec_right[(group*nshort) + offs + c] =
+                                    spec_left[(group*nshort) + offs + c];
+                            }
+                        } else /*if (ics_left->ms_mask_present == 0)*/ {
+#ifdef LTP_DEC
+                            ics_right->ltp.long_used[sfb] = 0;
+                            ics_right->ltp2.long_used[sfb] = 0;
+#endif
+#ifdef MAIN_DEC
+                            ics_right->pred.prediction_used[sfb] = 0;
+#endif
+
+                            offs = ics_right->swb_offset[sfb];
+                            size = ics_right->swb_offset[sfb+1] - offs;
+
+                            /* Generate random vector */
+                            gen_rand_vector(&spec_right[(group*nshort)+offs],
+                                ics_right->scale_factors[g][sfb], size, sub);
+                        }
+                    }
+                }
+            } /* sfb */
+            group++;
+        } /* b */
+    } /* g */
+}