diff options
Diffstat (limited to 'src/libfaad/ic_predict.c')
| -rw-r--r-- | src/libfaad/ic_predict.c | 177 |
1 files changed, 140 insertions, 37 deletions
diff --git a/src/libfaad/ic_predict.c b/src/libfaad/ic_predict.c index 997b2c654..31ae5d668 100644 --- a/src/libfaad/ic_predict.c +++ b/src/libfaad/ic_predict.c @@ -1,6 +1,6 @@ /* -** FAAD - Freeware Advanced Audio Decoder -** Copyright (C) 2002 M. Bakker +** 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 @@ -16,7 +16,13 @@ ** along with this program; if not, write to the Free Software ** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. ** -** $Id: ic_predict.c,v 1.2 2002/12/16 19:00:14 miguelfreitas Exp $ +** 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: ic_predict.c,v 1.3 2003/12/30 02:00:10 miguelfreitas Exp $ **/ #include "common.h" @@ -28,63 +34,161 @@ #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, predictedvalue; real_t e0, e1; real_t k1, k2; - real_t *r; - real_t *KOR; - real_t *VAR; + real_t r[2]; + real_t COR[2]; + real_t VAR[2]; - r = state->r; /* delay elements */ - KOR = state->KOR; /* correlations */ - VAR = state->VAR; /* variances */ + 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 (VAR[0] == 0) - k1 = 0; - else - k1 = KOR[0]/VAR[0]*B; + +#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]; + real_t tmp; + if (c == 0 || v <= 1) + { + k1 = 0; + } else { + tmp = B / v; + flt_round(&tmp); + k1 = c * tmp; + } + } +#endif if (pred) { - /* only needed for the actual predicted value, k1 is always needed */ - if (VAR[1] == 0) - k2 = 0; - else - k2 = KOR[1]/VAR[1]*B; +#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 - predictedvalue = MUL(k1, r[0]) + MUL(k2, r[1]); +#define B 0.953125 + real_t c = COR[1]; + real_t v = VAR[1]; + real_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; - } else { - *output = input; } /* calculate new state data */ e0 = *output; - e1 = e0 - MUL(k1, r[0]); + e1 = e0 - k1*r[0]; + dr1 = k1*e0; - dr1 = MUL(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; - VAR[0] = MUL(ALPHA, VAR[0]) + MUL(REAL_CONST(0.5), (MUL(r[0], r[0]) + MUL(e0, e0))); - KOR[0] = MUL(ALPHA, KOR[0]) + MUL(r[0], e0); - VAR[1] = MUL(ALPHA, VAR[1]) + MUL(REAL_CONST(0.5), (MUL(r[1], r[1]) + MUL(e1, e1))); - KOR[1] = MUL(ALPHA, KOR[1]) + MUL(r[1], e1); + r[1] = A * (r[0]-dr1); + r[0] = A * e0; - r[1] = MUL(A, (r[0]-dr1)); - r[0] = MUL(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->KOR[0] = 0; - state->KOR[1] = 0; - state->VAR[0] = REAL_CONST(1.0); - state->VAR[1] = REAL_CONST(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) @@ -125,7 +229,7 @@ void reset_all_predictors(pred_state *state, uint16_t frame_len) /* intra channel prediction */ void ic_prediction(ic_stream *ics, real_t *spec, pred_state *state, - uint16_t frame_len) + uint16_t frame_len, uint8_t sf_index) { uint8_t sfb; uint16_t bin; @@ -134,7 +238,7 @@ void ic_prediction(ic_stream *ics, real_t *spec, pred_state *state, { reset_all_predictors(state, frame_len); } else { - for (sfb = 0; sfb < ics->pred.limit; sfb++) + for (sfb = 0; sfb < max_pred_sfb(sf_index); sfb++) { uint16_t low = ics->swb_offset[sfb]; uint16_t high = ics->swb_offset[sfb+1]; @@ -142,8 +246,7 @@ void ic_prediction(ic_stream *ics, real_t *spec, pred_state *state, for (bin = low; bin < high; bin++) { ic_predict(&state[bin], spec[bin], &spec[bin], - (ics->predictor_data_present && - ics->pred.prediction_used[sfb])); + (ics->predictor_data_present && ics->pred.prediction_used[sfb])); } } |