diff options
Diffstat (limited to 'faad2/src/libfaad/ic_predict.c')
| -rw-r--r-- | faad2/src/libfaad/ic_predict.c | 271 |
1 files changed, 271 insertions, 0 deletions
diff --git a/faad2/src/libfaad/ic_predict.c b/faad2/src/libfaad/ic_predict.c new file mode 100644 index 0000000..f9e51bd --- /dev/null +++ b/faad2/src/libfaad/ic_predict.c @@ -0,0 +1,271 @@ +/*
+** 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: ic_predict.c,v 1.28 2007/11/01 12:33:31 menno Exp $
+**/
+
+#include "common.h"
+#include "structs.h"
+
+#ifdef MAIN_DEC
+
+#include "syntax.h"
+#include "ic_predict.h"
+#include "pns.h"
+
+
+static void flt_round(float32_t *pf)
+{
+ int32_t flg;
+ uint32_t tmp, tmp1, tmp2;
+
+ tmp = *(uint32_t*)pf;
+ flg = tmp & (uint32_t)0x00008000;
+ tmp &= (uint32_t)0xffff0000;
+ tmp1 = tmp;
+ /* round 1/2 lsb toward infinity */
+ if (flg)
+ {
+ tmp &= (uint32_t)0xff800000; /* extract exponent and sign */
+ tmp |= (uint32_t)0x00010000; /* insert 1 lsb */
+ tmp2 = tmp; /* add 1 lsb and elided one */
+ tmp &= (uint32_t)0xff800000; /* extract exponent and sign */
+
+ *pf = *(float32_t*)&tmp1 + *(float32_t*)&tmp2 - *(float32_t*)&tmp;
+ } else {
+ *pf = *(float32_t*)&tmp;
+ }
+}
+
+static int16_t quant_pred(float32_t x)
+{
+ int16_t q;
+ uint32_t *tmp = (uint32_t*)&x;
+
+ q = (int16_t)(*tmp>>16);
+
+ return q;
+}
+
+static float32_t inv_quant_pred(int16_t q)
+{
+ float32_t x;
+ uint32_t *tmp = (uint32_t*)&x;
+ *tmp = ((uint32_t)q)<<16;
+
+ return x;
+}
+
+static void ic_predict(pred_state *state, real_t input, real_t *output, uint8_t pred)
+{
+ uint16_t tmp;
+ int16_t i, j;
+ real_t dr1;
+ float32_t predictedvalue;
+ real_t e0, e1;
+ real_t k1, k2;
+
+ real_t r[2];
+ real_t COR[2];
+ real_t VAR[2];
+
+ r[0] = inv_quant_pred(state->r[0]);
+ r[1] = inv_quant_pred(state->r[1]);
+ COR[0] = inv_quant_pred(state->COR[0]);
+ COR[1] = inv_quant_pred(state->COR[1]);
+ VAR[0] = inv_quant_pred(state->VAR[0]);
+ VAR[1] = inv_quant_pred(state->VAR[1]);
+
+
+#if 1
+ tmp = state->VAR[0];
+ j = (tmp >> 7);
+ i = tmp & 0x7f;
+ if (j >= 128)
+ {
+ j -= 128;
+ k1 = COR[0] * exp_table[j] * mnt_table[i];
+ } else {
+ k1 = REAL_CONST(0);
+ }
+#else
+
+ {
+#define B 0.953125
+ real_t c = COR[0];
+ real_t v = VAR[0];
+ float32_t tmp;
+ if (c == 0 || v <= 1)
+ {
+ k1 = 0;
+ } else {
+ tmp = B / v;
+ flt_round(&tmp);
+ k1 = c * tmp;
+ }
+ }
+#endif
+
+ if (pred)
+ {
+#if 1
+ tmp = state->VAR[1];
+ j = (tmp >> 7);
+ i = tmp & 0x7f;
+ if (j >= 128)
+ {
+ j -= 128;
+ k2 = COR[1] * exp_table[j] * mnt_table[i];
+ } else {
+ k2 = REAL_CONST(0);
+ }
+#else
+
+#define B 0.953125
+ real_t c = COR[1];
+ real_t v = VAR[1];
+ float32_t tmp;
+ if (c == 0 || v <= 1)
+ {
+ k2 = 0;
+ } else {
+ tmp = B / v;
+ flt_round(&tmp);
+ k2 = c * tmp;
+ }
+#endif
+
+ predictedvalue = k1*r[0] + k2*r[1];
+ flt_round(&predictedvalue);
+ *output = input + predictedvalue;
+ }
+
+ /* calculate new state data */
+ e0 = *output;
+ e1 = e0 - k1*r[0];
+ dr1 = k1*e0;
+
+ VAR[0] = ALPHA*VAR[0] + 0.5f * (r[0]*r[0] + e0*e0);
+ COR[0] = ALPHA*COR[0] + r[0]*e0;
+ VAR[1] = ALPHA*VAR[1] + 0.5f * (r[1]*r[1] + e1*e1);
+ COR[1] = ALPHA*COR[1] + r[1]*e1;
+
+ r[1] = A * (r[0]-dr1);
+ r[0] = A * e0;
+
+ state->r[0] = quant_pred(r[0]);
+ state->r[1] = quant_pred(r[1]);
+ state->COR[0] = quant_pred(COR[0]);
+ state->COR[1] = quant_pred(COR[1]);
+ state->VAR[0] = quant_pred(VAR[0]);
+ state->VAR[1] = quant_pred(VAR[1]);
+}
+
+static void reset_pred_state(pred_state *state)
+{
+ state->r[0] = 0;
+ state->r[1] = 0;
+ state->COR[0] = 0;
+ state->COR[1] = 0;
+ state->VAR[0] = 0x3F80;
+ state->VAR[1] = 0x3F80;
+}
+
+void pns_reset_pred_state(ic_stream *ics, pred_state *state)
+{
+ uint8_t sfb, g, b;
+ uint16_t i, offs, offs2;
+
+ /* prediction only for long blocks */
+ if (ics->window_sequence == EIGHT_SHORT_SEQUENCE)
+ return;
+
+ for (g = 0; g < ics->num_window_groups; g++)
+ {
+ for (b = 0; b < ics->window_group_length[g]; b++)
+ {
+ for (sfb = 0; sfb < ics->max_sfb; sfb++)
+ {
+ if (is_noise(ics, g, sfb))
+ {
+ offs = ics->swb_offset[sfb];
+ offs2 = min(ics->swb_offset[sfb+1], ics->swb_offset_max);
+
+ for (i = offs; i < offs2; i++)
+ reset_pred_state(&state[i]);
+ }
+ }
+ }
+ }
+}
+
+void reset_all_predictors(pred_state *state, uint16_t frame_len)
+{
+ uint16_t i;
+
+ for (i = 0; i < frame_len; i++)
+ reset_pred_state(&state[i]);
+}
+
+/* intra channel prediction */
+void ic_prediction(ic_stream *ics, real_t *spec, pred_state *state,
+ uint16_t frame_len, uint8_t sf_index)
+{
+ uint8_t sfb;
+ uint16_t bin;
+
+ if (ics->window_sequence == EIGHT_SHORT_SEQUENCE)
+ {
+ reset_all_predictors(state, frame_len);
+ } else {
+ for (sfb = 0; sfb < max_pred_sfb(sf_index); sfb++)
+ {
+ uint16_t low = ics->swb_offset[sfb];
+ uint16_t high = min(ics->swb_offset[sfb+1], ics->swb_offset_max);
+
+ for (bin = low; bin < high; bin++)
+ {
+ ic_predict(&state[bin], spec[bin], &spec[bin],
+ (ics->predictor_data_present && ics->pred.prediction_used[sfb]));
+ }
+ }
+
+ if (ics->predictor_data_present)
+ {
+ if (ics->pred.predictor_reset)
+ {
+ for (bin = ics->pred.predictor_reset_group_number - 1;
+ bin < frame_len; bin += 30)
+ {
+ reset_pred_state(&state[bin]);
+ }
+ }
+ }
+ }
+}
+
+#endif
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