/* ***************************************************************************** * * GSM AMR-NB speech codec R98 Version 7.6.0 December 12, 2001 * R99 Version 3.3.0 * REL-4 Version 4.1.0 * ***************************************************************************** * * File : gc_pred.c * Purpose : codebook gain MA prediction * ***************************************************************************** */ /* ***************************************************************************** * MODULE INCLUDE FILE AND VERSION ID ***************************************************************************** */ #include "gc_pred.h" const char gc_pred_id[] = "@(#)$Id $" gc_pred_h; /* ***************************************************************************** * INCLUDE FILES ***************************************************************************** */ #include #include #include "typedef.h" #include "basic_op.h" #include "oper_32b.h" #include "cnst.h" #include "count.h" #include "log2.h" #include "copy.h" /* ***************************************************************************** * LOCAL VARIABLES AND TABLES ***************************************************************************** */ #define NPRED 4 /* number of prediction taps */ /* MA prediction coefficients (Q13) */ static const Word16 pred[NPRED] = {5571, 4751, 2785, 1556}; /* average innovation energy. */ /* MEAN_ENER = 36.0/constant, constant = 20*Log10(2) */ #define MEAN_ENER_MR122 783741L /* 36/(20*log10(2)) (Q17) */ /* MA prediction coefficients (Q6) */ static const Word16 pred_MR122[NPRED] = {44, 37, 22, 12}; /* minimum quantized energy: -14 dB */ #define MIN_ENERGY -14336 /* 14 Q10 */ #define MIN_ENERGY_MR122 -2381 /* 14 / (20*log10(2)) Q10 */ /* ***************************************************************************** * PUBLIC PROGRAM CODE ***************************************************************************** */ /************************************************************************* * * Function: qua_gain_init * Purpose: Allocates state memory and initializes state memory * ************************************************************************** */ int gc_pred_init (gc_predState **state) { gc_predState* s; if (state == (gc_predState **) NULL){ wfprintf(stderr, "gc_pred_init: invalid parameter\n"); return -1; } *state = NULL; /* allocate memory */ if ((s= (gc_predState *) wmalloc(sizeof(gc_predState))) == NULL){ wfprintf(stderr, "gc_pred_init: can not malloc state structure\n"); return -1; } gc_pred_reset(s); *state = s; return 0; } /************************************************************************* * * Function: gc_pred_reset * Purpose: Initializes state memory to zero * ************************************************************************** */ int gc_pred_reset (gc_predState *state) { Word16 i; if (state == (gc_predState *) NULL){ wfprintf(stderr, "gc_pred_reset: invalid parameter\n"); return -1; } for(i = 0; i < NPRED; i++) { state->past_qua_en[i] = MIN_ENERGY; state->past_qua_en_MR122[i] = MIN_ENERGY_MR122; } return 0; } /************************************************************************* * * Function: gc_pred_exit * Purpose: The memory used for state memory is freed * ************************************************************************** */ void gc_pred_exit (gc_predState **state) { if (state == NULL || *state == NULL) return; /* deallocate memory */ wfree(*state); *state = NULL; return; } /************************************************************************* * * FUNCTION: gc_pred_copy() * * PURPOSE: Copy MA predictor state variable * *************************************************************************/ void gc_pred_copy( gc_predState *st_src, /* i : State struct */ gc_predState *st_dest /* o : State struct */ ) { Copy (st_src->past_qua_en, st_dest->past_qua_en, NPRED); Copy (st_src->past_qua_en_MR122, st_dest->past_qua_en_MR122, NPRED); } /************************************************************************* * * FUNCTION: gc_pred() * * PURPOSE: MA prediction of the innovation energy * (in dB/(20*log10(2))) with mean removed). * *************************************************************************/ void gc_pred( gc_predState *st, /* i/o: State struct */ enum Mode mode, /* i : AMR mode */ Word16 *code, /* i : innovative codebook vector (L_SUBFR) */ /* MR122: Q12, other modes: Q13 */ Word16 *exp_gcode0, /* o : exponent of predicted gain factor, Q0 */ Word16 *frac_gcode0,/* o : fraction of predicted gain factor Q15 */ Word16 *exp_en, /* o : exponent of innovation energy, Q0 */ /* (only calculated for MR795) */ Word16 *frac_en /* o : fraction of innovation energy, Q15 */ /* (only calculated for MR795) */ ) { Word16 i; Word32 ener_code; Word16 exp, frac; /*-------------------------------------------------------------------* * energy of code: * * ~~~~~~~~~~~~~~~ * * ener_code = sum(code[i]^2) * *-------------------------------------------------------------------*/ ener_code = L_mac_ex((Word32) 0, code[0], code[0]); /* MR122: Q12*Q12 -> Q25 */ /* others: Q13*Q13 -> Q27 */ for (i = 1; i < L_SUBFR; i++) ener_code = L_mac_ex(ener_code, code[i], code[i]); test (); if (sub_ex (mode, MR122) == 0) { Word32 ener; /* ener_code = ener_code / lcode; lcode = 40; 1/40 = 26214 Q20 */ ener_code = L_mult_ex (round_ex (ener_code), 26214); /* Q9 * Q20 -> Q30 */ /*-------------------------------------------------------------------* * energy of code: * * ~~~~~~~~~~~~~~~ * * ener_code(Q17) = 10 * Log10(energy) / constant * * = 1/2 * Log2(energy) * * constant = 20*Log10(2) * *-------------------------------------------------------------------*/ /* ener_code = 1/2 * Log2(ener_code); Note: Log2=log2+30 */ Log2(ener_code, &exp, &frac); ener_code = L_Comp (sub_ex (exp, 30), frac); /* Q16 for log() */ /* ->Q17 for 1/2 log()*/ /*-------------------------------------------------------------------* * predicted energy: * * ~~~~~~~~~~~~~~~~~ * * ener(Q24) = (Emean + sum{pred[i]*past_en[i]})/constant * * = MEAN_ENER + sum(pred[i]*past_qua_en[i]) * * constant = 20*Log10(2) * *-------------------------------------------------------------------*/ ener = MEAN_ENER_MR122; move32 (); /* Q24 (Q17) */ for (i = 0; i < NPRED; i++) { ener = L_mac_ex (ener, st->past_qua_en_MR122[i], pred_MR122[i]); /* Q10 * Q13 -> Q24 */ /* Q10 * Q6 -> Q17 */ } /*-------------------------------------------------------------------* * predicted codebook gain * * ~~~~~~~~~~~~~~~~~~~~~~~ * * gc0 = Pow10( (ener*constant - ener_code*constant) / 20 ) * * = Pow2(ener-ener_code) * * = Pow2(int(d)+frac(d)) * * * * (store exp and frac for pow2()) * *-------------------------------------------------------------------*/ ener = L_shr_ex (L_sub_ex (ener, ener_code), 1); /* Q16 */ L_Extract(ener, exp_gcode0, frac_gcode0); } else /* all modes except 12.2 */ { Word32 L_tmp; Word16 exp_code, gcode0; /*-----------------------------------------------------------------* * Compute: means_ener - 10log10(ener_code/ L_sufr) * *-----------------------------------------------------------------*/ exp_code = norm_l_ex (ener_code); ener_code = L_shl_ex (ener_code, exp_code); /* Log2 = log2 + 27 */ Log2_norm (ener_code, exp_code, &exp, &frac); /* fact = 10/log2(10) = 3.01 = 24660 Q13 */ L_tmp = Mpy_32_16(exp, frac, -24660); /* Q0.Q15 * Q13 -> Q14 */ /* L_tmp = means_ener - 10log10(ener_code/L_SUBFR) * = means_ener - 10log10(ener_code) + 10log10(L_SUBFR) * = K - fact * Log2(ener_code) * = K - fact * log2(ener_code) - fact*27 * * ==> K = means_ener + fact*27 + 10log10(L_SUBFR) * * means_ener = 33 = 540672 Q14 (MR475, MR515, MR59) * means_ener = 28.75 = 471040 Q14 (MR67) * means_ener = 30 = 491520 Q14 (MR74) * means_ener = 36 = 589824 Q14 (MR795) * means_ener = 33 = 540672 Q14 (MR102) * 10log10(L_SUBFR) = 16.02 = 262481.51 Q14 * fact * 27 = 1331640 Q14 * ----------------------------------------- * (MR475, MR515, MR59) K = 2134793.51 Q14 ~= 16678 * 64 * 2 * (MR67) K = 2065161.51 Q14 ~= 32268 * 32 * 2 * (MR74) K = 2085641.51 Q14 ~= 32588 * 32 * 2 * (MR795) K = 2183945.51 Q14 ~= 17062 * 64 * 2 * (MR102) K = 2134793.51 Q14 ~= 16678 * 64 * 2 */ if (test (), sub_ex (mode, MR102) == 0) { /* mean = 33 dB */ L_tmp = L_mac_ex(L_tmp, 16678, 64); /* Q14 */ } else if (test (), sub_ex (mode, MR795) == 0) { /* ener_code = * 2^27*2^exp_code frac_en = ener_code / 2^16 = * 2^11*2^exp_code = *2^11*2^exp * 2^exp_en := frac_en * 2^exp_en ==> exp_en = -11-exp_code; */ *frac_en = extract_h_ex (ener_code); move16 (); *exp_en = sub_ex (-11, exp_code); move16 (); /* mean = 36 dB */ L_tmp = L_mac_ex(L_tmp, 17062, 64); /* Q14 */ } else if (test (), sub_ex (mode, MR74) == 0) { /* mean = 30 dB */ L_tmp = L_mac_ex(L_tmp, 32588, 32); /* Q14 */ } else if (test (), sub_ex (mode, MR67) == 0) { /* mean = 28.75 dB */ L_tmp = L_mac_ex(L_tmp, 32268, 32); /* Q14 */ } else /* MR59, MR515, MR475 */ { /* mean = 33 dB */ L_tmp = L_mac_ex(L_tmp, 16678, 64); /* Q14 */ } /*-----------------------------------------------------------------* * Compute gcode0. * * = Sum(i=0,3) pred[i]*past_qua_en[i] - ener_code + mean_ener * *-----------------------------------------------------------------*/ L_tmp = L_shl_ex(L_tmp, 10); /* Q24 */ for (i = 0; i < 4; i++) L_tmp = L_mac_ex(L_tmp, pred[i], st->past_qua_en[i]); /* Q13 * Q10 -> Q24 */ gcode0 = extract_h_ex(L_tmp); /* Q8 */ /*-----------------------------------------------------------------* * gcode0 = pow(10.0, gcode0/20) * * = pow(2, 3.3219*gcode0/20) * * = pow(2, 0.166*gcode0) * *-----------------------------------------------------------------*/ /* 5439 Q15 = 0.165985 */ /* (correct: 1/(20*log10(2)) 0.166096 = 5443 Q15) */ test (); if (sub_ex (mode, MR74) == 0) /* For IS641 bitexactness */ L_tmp = L_mult_ex(gcode0, 5439); /* Q8 * Q15 -> Q24 */ else L_tmp = L_mult_ex(gcode0, 5443); /* Q8 * Q15 -> Q24 */ L_tmp = L_shr_ex(L_tmp, 8); /* -> Q16 */ L_Extract(L_tmp, exp_gcode0, frac_gcode0); /* -> Q0.Q15 */ } } /************************************************************************* * * FUNCTION: gc_pred_update() * * PURPOSE: update MA predictor with last quantized energy * *************************************************************************/ void gc_pred_update( gc_predState *st, /* i/o: State struct */ Word16 qua_ener_MR122, /* i : quantized energy for update, Q10 */ /* (log2(qua_err)) */ Word16 qua_ener /* i : quantized energy for update, Q10 */ /* (20*log10(qua_err)) */ ) { Word16 i; for (i = 3; i > 0; i--) { st->past_qua_en[i] = st->past_qua_en[i - 1]; move16 (); st->past_qua_en_MR122[i] = st->past_qua_en_MR122[i - 1]; move16 (); } st->past_qua_en_MR122[0] = qua_ener_MR122; /* log2 (qua_err), Q10 */ move16 (); st->past_qua_en[0] = qua_ener; /* 20*log10(qua_err), Q10 */ move16 (); } /************************************************************************* * * FUNCTION: gc_pred_average_limited() * * PURPOSE: get average of MA predictor state values (with a lower limit) * [used in error concealment] * *************************************************************************/ void gc_pred_average_limited( gc_predState *st, /* i: State struct */ Word16 *ener_avg_MR122, /* o: everaged quantized energy, Q10 */ /* (log2(qua_err)) */ Word16 *ener_avg /* o: averaged quantized energy, Q10 */ /* (20*log10(qua_err)) */ ) { Word16 av_pred_en; Word16 i; /* do average in MR122 mode (log2() domain) */ av_pred_en = 0; move16 (); for (i = 0; i < NPRED; i++) { av_pred_en = add_ex (av_pred_en, st->past_qua_en_MR122[i]); } /* av_pred_en = 0.25*av_pred_en */ av_pred_en = mult_ex (av_pred_en, 8192); /* if (av_pred_en < -14/(20Log10(2))) av_pred_en = .. */ test (); if (sub_ex (av_pred_en, MIN_ENERGY_MR122) < 0) { av_pred_en = MIN_ENERGY_MR122; move16 (); } *ener_avg_MR122 = av_pred_en; move16 (); /* do average for other modes (20*log10() domain) */ av_pred_en = 0; move16 (); for (i = 0; i < NPRED; i++) { av_pred_en = add_ex (av_pred_en, st->past_qua_en[i]); } /* av_pred_en = 0.25*av_pred_en */ av_pred_en = mult_ex (av_pred_en, 8192); /* if (av_pred_en < -14) av_pred_en = .. */ test (); if (sub_ex (av_pred_en, MIN_ENERGY) < 0) { av_pred_en = MIN_ENERGY; move16 (); } *ener_avg = av_pred_en; move16 (); }