FreeCalypso > hg > gsm-codec-lib
view libgsmefr/q_gains.c @ 489:f036e1de5b05
libgsmhr1: starting with API definition
author | Mychaela Falconia <falcon@freecalypso.org> |
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date | Sat, 15 Jun 2024 04:51:30 +0000 |
parents | 33487966077e |
children |
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/*--------------------------------------------------------------------------* * Function q_gain_pitch(), q_gain_code() * * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * * Scalar quantization of the pitch gain and the innovative codebook gain. * * * * MA prediction is performed on the innovation energy * * (in dB/(20*log10(2))) with mean removed. * *-------------------------------------------------------------------------*/ #include "gsm_efr.h" #include "typedef.h" #include "namespace.h" #include "basic_op.h" #include "oper_32b.h" #include "no_count.h" #include "sig_proc.h" #include "codec.h" #include "gains_tb.h" #include "cnst.h" #include "dtx.h" #include "enc_state.h" Word16 q_gain_pitch ( /* Return index of quantization */ Word16 *gain /* (i) : Pitch gain to quantize */ ) { Word16 i, index, gain_q14, err, err_min; gain_q14 = shl (*gain, 2); err_min = abs_s (sub (gain_q14, qua_gain_pitch[0])); index = 0; move16 (); for (i = 1; i < NB_QUA_PITCH; i++) { err = abs_s (sub (gain_q14, qua_gain_pitch[i])); test (); if (err < err_min) { err_min = err; move16 (); index = i; move16 (); } } *gain = shr (qua_gain_pitch[index], 2); move16 (); return index; } /* average innovation energy. */ /* MEAN_ENER = 36.0/constant, constant = 20*Log10(2) */ #define MEAN_ENER 783741L /* 36/(20*log10(2)) */ Word16 q_gain_code ( /* Return quantization index */ struct EFR_encoder_state *st, Word16 code[], /* (i) : fixed codebook excitation */ Word16 lcode, /* (i) : codevector size */ Word16 *gain, /* (i/o) : quantized fixed codebook gain */ Word16 txdtx_ctrl, Word16 i_subfr ) { Word16 i, index; Word16 gcode0, err, err_min, exp, frac; Word32 ener, ener_code; Word16 aver_gain; if ((txdtx_ctrl & TX_SP_FLAG) != 0) { /*-------------------------------------------------------------------* * energy of code: * * ~~~~~~~~~~~~~~~ * * ener_code(Q17) = 10 * Log10(energy/lcode) / constant * * = 1/2 * Log2(energy/lcode) * * constant = 20*Log10(2) * *-------------------------------------------------------------------*/ /* ener_code = log10(ener_code/lcode) / (20*log10(2)) */ ener_code = 0; move32 (); for (i = 0; i < lcode; i++) { ener_code = L_mac (ener_code, code[i], code[i]); } /* ener_code = ener_code / lcode */ ener_code = L_mult (round (ener_code), 26214); /* ener_code = 1/2 * Log2(ener_code) */ Log2 (ener_code, &exp, &frac); ener_code = L_Comp (sub (exp, 30), frac); /* predicted energy */ ener = MEAN_ENER; move32 (); for (i = 0; i < 4; i++) { ener = L_mac (ener, st->past_qua_en[i], st->pred[i]); } /*-------------------------------------------------------------------* * predicted codebook gain * * ~~~~~~~~~~~~~~~~~~~~~~~ * * gcode0(Qx) = Pow10( (ener*constant - ener_code*constant) / 20 ) * * = Pow2(ener-ener_code) * * constant = 20*Log10(2) * *-------------------------------------------------------------------*/ ener = L_shr (L_sub (ener, ener_code), 1); L_Extract (ener, &exp, &frac); gcode0 = extract_l (Pow2 (exp, frac)); /* predicted gain */ gcode0 = shl (gcode0, 4); /*-------------------------------------------------------------------* * Search for best quantizer * *-------------------------------------------------------------------*/ err_min = abs_s (sub (*gain, mult (gcode0, qua_gain_code[0]))); index = 0; move16 (); for (i = 1; i < NB_QUA_CODE; i++) { err = abs_s (sub (*gain, mult (gcode0, qua_gain_code[i]))); test (); if (err < err_min) { err_min = err; move16 (); index = i; move16 (); } } *gain = mult (gcode0, qua_gain_code[index]); move16 (); /*------------------------------------------------------------------* * update table of past quantized energies * * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * * past_qua_en(Q12) = 20 * Log10(qua_gain_code) / constant * * = Log2(qua_gain_code) * * constant = 20*Log10(2) * *------------------------------------------------------------------*/ for (i = 3; i > 0; i--) { st->past_qua_en[i] = st->past_qua_en[i - 1]; } Log2 (L_deposit_l (qua_gain_code[index]), &exp, &frac); st->past_qua_en[0] = shr (frac, 5); st->past_qua_en[0] = add (st->past_qua_en[0], shl (sub (exp, 11), 10)); update_gain_code_history_tx (st, *gain); } else { if ((txdtx_ctrl & TX_PREV_HANGOVER_ACTIVE) != 0 && (i_subfr == 0)) { st->gcode0_CN = update_gcode0_CN (st->gain_code_old_tx); st->gcode0_CN = shl (st->gcode0_CN, 4); } *gain = st->CN_excitation_gain; if ((txdtx_ctrl & TX_SID_UPDATE) != 0) { aver_gain = aver_gain_code_history (st->CN_excitation_gain, st->gain_code_old_tx); /*---------------------------------------------------------------* * Search for best quantizer * *---------------------------------------------------------------*/ err_min = abs_s (sub (aver_gain, mult (st->gcode0_CN, qua_gain_code[0]))); index = 0; for (i = 1; i < NB_QUA_CODE; i++) { err = abs_s (sub (aver_gain, mult (st->gcode0_CN, qua_gain_code[i]))); if (err < err_min) { err_min = err; move16 (); index = i; move16 (); } } } update_gain_code_history_tx (st, *gain); /*-------------------------------------------------------------------* * reset table of past quantized energies * * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * *-------------------------------------------------------------------*/ for (i = 0; i < 4; i++) { st->past_qua_en[i] = -2381; } } return index; }