FreeCalypso > hg > gsm-codec-lib
view libtwamr/dec_amr.c @ 452:6e595f7d40e2
CHANGES: document changes for the upcoming release
author | Mychaela Falconia <falcon@freecalypso.org> |
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date | Fri, 10 May 2024 03:45:47 +0000 |
parents | 7bef001cd8b8 |
children |
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/************************************************************************* * * 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 : dec_amr.c * Purpose : Decoding of one speech frame using given codec mode * ***************************************************************************** */ /* ***************************************************************************** * MODULE INCLUDE FILE AND VERSION ID ***************************************************************************** */ #include "namespace.h" #include "dec_amr.h" #include "typedef.h" #include "basic_op.h" #include "no_count.h" #include "cnst.h" #include "memops.h" #include "syn_filt.h" #include "d_plsf.h" #include "agc.h" #include "int_lpc.h" #include "dec_gain.h" #include "dec_lag3.h" #include "dec_lag6.h" #include "d2_9pf.h" #include "d2_11pf.h" #include "d3_14pf.h" #include "d4_17pf.h" #include "d8_31pf.h" #include "d1035pf.h" #include "pred_lt.h" #include "d_gain_p.h" #include "d_gain_c.h" #include "dec_gain.h" #include "ec_gains.h" #include "ph_disp.h" #include "c_g_aver.h" #include "int_lsf.h" #include "lsp_lsf.h" #include "lsp_avg.h" #include "bgnscd.h" #include "ex_ctrl.h" #include "sqrt_l.h" #include "lsp_tab.h" #include "bitno.h" #include "b_cn_cod.h" /* ***************************************************************************** * LOCAL VARIABLES AND TABLES ***************************************************************************** */ /*-----------------------------------------------------------------* * Decoder constant parameters (defined in "cnst.h") * *-----------------------------------------------------------------* * L_FRAME : Frame size. * * L_FRAME_BY2 : Half the frame size. * * L_SUBFR : Sub-frame size. * * M : LPC order. * * MP1 : LPC order+1 * * PIT_MIN : Minimum pitch lag. * * PIT_MIN_MR122 : Minimum pitch lag for the MR122 mode. * * PIT_MAX : Maximum pitch lag. * * L_INTERPOL : Length of filter for interpolation * * PRM_SIZE : size of vector containing analysis parameters * *-----------------------------------------------------------------*/ /* ***************************************************************************** * PUBLIC PROGRAM CODE ***************************************************************************** */ /* ************************************************************************** * * Function : Decoder_amr_reset * Purpose : Resets state memory * ************************************************************************** */ void Decoder_amr_reset (Decoder_amrState *state, Flag dtx_partial_reset) { Word16 i; /* Initialize static pointer */ state->exc = state->old_exc + PIT_MAX + L_INTERPOL; /* Static vectors to zero */ Set_zero (state->old_exc, PIT_MAX + L_INTERPOL); if (!dtx_partial_reset) Set_zero (state->mem_syn, M); /* initialize pitch sharpening */ state->sharp = SHARPMIN; state->old_T0 = 40; /* Initialize state->lsp_old [] */ if (!dtx_partial_reset) { Copy(lsp_init_data, &state->lsp_old[0], M); } /* Initialize memories of bad frame handling */ state->prev_bf = 0; state->prev_pdf = 0; state->state = 0; state->T0_lagBuff = 40; state->inBackgroundNoise = 0; state->voicedHangover = 0; if (!dtx_partial_reset) { for (i=0;i<9;i++) state->excEnergyHist[i] = 0; } for (i = 0; i < 9; i++) state->ltpGainHistory[i] = 0; Cb_gain_average_reset(&state->Cb_gain_averState); if (!dtx_partial_reset) lsp_avg_reset(&state->lsp_avg_st); D_plsf_reset(&state->lsfState); ec_gain_pitch_reset(&state->ec_gain_p_st); ec_gain_code_reset(&state->ec_gain_c_st); if (!dtx_partial_reset) gc_pred_reset(&state->pred_state); Bgn_scd_reset(&state->background_state); state->nodataSeed = 21845; ph_disp_reset(&state->ph_disp_st); if (!dtx_partial_reset) dtx_dec_reset(&state->dtxDecoderState); } /* ************************************************************************** * * Function : Decoder_amr * Purpose : Speech decoder routine. * ************************************************************************** */ int Decoder_amr ( Decoder_amrState *st, /* i/o : State variables */ enum Mode mode, /* i : AMR mode */ Word16 parm[], /* i : vector of synthesis parameters (PRM_SIZE) */ enum RXFrameType frame_type, /* i : received frame type */ Word16 synth[], /* o : synthesis speech (L_FRAME) */ Word16 A_t[] /* o : decoded LP filter in 4 subframes (AZ_SIZE) */ ) { /* LPC coefficients */ Word16 *Az; /* Pointer on A_t */ /* LSPs */ Word16 lsp_new[M]; Word16 lsp_mid[M]; /* LSFs */ Word16 prev_lsf[M]; Word16 lsf_i[M]; /* Algebraic codevector */ Word16 code[L_SUBFR]; /* excitation */ Word16 excp[L_SUBFR]; Word16 exc_enhanced[L_SUBFR]; /* Scalars */ Word16 i, i_subfr; Word16 T0, T0_frac, index, index_mr475 = 0; Word16 gain_pit, gain_code, gain_code_mix, pit_sharp, pit_flag, pitch_fac; Word16 t0_min, t0_max; Word16 delta_frc_low, delta_frc_range; Word16 tmp_shift; Word16 temp; Word32 L_temp; Word16 flag4; Word16 carefulFlag; Word16 excEnergy; Word16 subfrNr; Word16 evenSubfr = 0; Word16 bfi = 0; /* bad frame indication flag */ Word16 pdfi = 0; /* potential degraded bad frame flag */ enum DTXStateType newDTXState; /* SPEECH , DTX, DTX_MUTE */ /* find the new DTX state SPEECH OR DTX */ newDTXState = rx_dtx_handler(&st->dtxDecoderState, frame_type); /* DTX actions */ if (sub(newDTXState, SPEECH) != 0 ) { Decoder_amr_reset (st, 1); dtx_dec(&st->dtxDecoderState, st->mem_syn, &st->lsfState, &st->pred_state, &st->Cb_gain_averState, newDTXState, mode, parm, synth, A_t); /* update average lsp */ Lsf_lsp(st->lsfState.past_lsf_q, st->lsp_old, M); lsp_avg(&st->lsp_avg_st, st->lsfState.past_lsf_q); goto the_end; } /* SPEECH action state machine */ if ((sub(frame_type, RX_SPEECH_BAD) == 0) || (sub(frame_type, RX_NO_DATA) == 0) || (sub(frame_type, RX_ONSET) == 0)) { bfi = 1; if ((sub(frame_type, RX_NO_DATA) == 0) || (sub(frame_type, RX_ONSET) == 0)) { build_CN_param(&st->nodataSeed, prmno[mode], bitno[mode], parm); } } else if (sub(frame_type, RX_SPEECH_DEGRADED) == 0) { pdfi = 1; } if (bfi != 0) { st->state = add (st->state, 1); } else if (sub (st->state, 6) == 0) { st->state = 5; move16 (); } else { st->state = 0; move16 (); } if (sub (st->state, 6) > 0) { st->state = 6; move16 (); } /* If this frame is the first speech frame after CNI period, */ /* set the BFH state machine to an appropriate state depending */ /* on whether there was DTX muting before start of speech or not */ /* If there was DTX muting, the first speech frame is muted. */ /* If there was no DTX muting, the first speech frame is not */ /* muted. The BFH state machine starts from state 5, however, to */ /* keep the audible noise resulting from a SID frame which is */ /* erroneously interpreted as a good speech frame as small as */ /* possible (the decoder output in this case is quickly muted) */ if (sub(st->dtxDecoderState.dtxGlobalState, DTX) == 0) { st->state = 5; st->prev_bf = 0; } else if (test (), sub(st->dtxDecoderState.dtxGlobalState, DTX_MUTE) == 0) { st->state = 5; st->prev_bf = 1; } /* save old LSFs for CB gain smoothing */ Copy (st->lsfState.past_lsf_q, prev_lsf, M); /* decode LSF parameters and generate interpolated lpc coefficients for the 4 subframes */ if (sub (mode, MR122) != 0) { D_plsf_3(&st->lsfState, mode, bfi, parm, lsp_new); /* Advance synthesis parameters pointer */ parm += 3; move16 (); Int_lpc_1to3(st->lsp_old, lsp_new, A_t); } else { D_plsf_5(&st->lsfState, bfi, parm, lsp_mid, lsp_new); /* Advance synthesis parameters pointer */ parm += 5; move16 (); Int_lpc_1and3(st->lsp_old, lsp_mid, lsp_new, A_t); } /* update the LSPs for the next frame */ for (i = 0; i < M; i++) { st->lsp_old[i] = lsp_new[i]; move16 (); } /*------------------------------------------------------------------------* * Loop for every subframe in the analysis frame * *------------------------------------------------------------------------* * The subframe size is L_SUBFR and the loop is repeated L_FRAME/L_SUBFR * * times * * - decode the pitch delay * * - decode algebraic code * * - decode pitch and codebook gains * * - find the excitation and compute synthesis speech * *------------------------------------------------------------------------*/ /* pointer to interpolated LPC parameters */ Az = A_t; move16 (); evenSubfr = 0; move16(); subfrNr = -1; move16(); for (i_subfr = 0; i_subfr < L_FRAME; i_subfr += L_SUBFR) { subfrNr = add(subfrNr, 1); evenSubfr = sub(1, evenSubfr); /* flag for first and 3th subframe */ pit_flag = i_subfr; move16 (); test(); if (sub (i_subfr, L_FRAME_BY2) == 0) { test(); test(); if (sub(mode, MR475) != 0 && sub(mode, MR515) != 0) { pit_flag = 0; move16 (); } } /* pitch index */ index = *parm++; move16 (); /*-------------------------------------------------------* * - decode pitch lag and find adaptive codebook vector. * *-------------------------------------------------------*/ test (); if (sub(mode, MR122) != 0) { /* flag4 indicates encoding with 4 bit resolution; */ /* this is needed for mode MR475, MR515, MR59 and MR67 */ flag4 = 0; move16 (); test (); test (); test (); test (); if ((sub (mode, MR475) == 0) || (sub (mode, MR515) == 0) || (sub (mode, MR59) == 0) || (sub (mode, MR67) == 0) ) { flag4 = 1; move16 (); } /*-------------------------------------------------------* * - get ranges for the t0_min and t0_max * * - only needed in delta decoding * *-------------------------------------------------------*/ delta_frc_low = 5; move16(); delta_frc_range = 9; move16(); test (); if ( sub(mode, MR795) == 0 ) { delta_frc_low = 10; move16(); delta_frc_range = 19; move16(); } t0_min = sub(st->old_T0, delta_frc_low); test (); if (sub(t0_min, PIT_MIN) < 0) { t0_min = PIT_MIN; move16(); } t0_max = add(t0_min, delta_frc_range); test (); if (sub(t0_max, PIT_MAX) > 0) { t0_max = PIT_MAX; move16(); t0_min = sub(t0_max, delta_frc_range); } Dec_lag3 (index, t0_min, t0_max, pit_flag, st->old_T0, &T0, &T0_frac, flag4); st->T0_lagBuff = T0; move16 (); test (); if (bfi != 0) { test (); if (sub (st->old_T0, PIT_MAX) < 0) { /* Graceful pitch */ st->old_T0 = add(st->old_T0, 1); /* degradation */ } T0 = st->old_T0; move16 (); T0_frac = 0; move16 (); test (); test (); test (); test (); test (); if ( st->inBackgroundNoise != 0 && sub(st->voicedHangover, 4) > 0 && ((sub(mode, MR475) == 0 ) || (sub(mode, MR515) == 0 ) || (sub(mode, MR59) == 0) ) ) { T0 = st->T0_lagBuff; move16 (); } } Pred_lt_3or6 (st->exc, T0, T0_frac, L_SUBFR, 1); } else { Dec_lag6 (index, PIT_MIN_MR122, PIT_MAX, pit_flag, &T0, &T0_frac); test (); test (); test (); if ( bfi == 0 && (pit_flag == 0 || sub (index, 61) < 0)) { } else { st->T0_lagBuff = T0; move16 (); T0 = st->old_T0; move16 (); T0_frac = 0; move16 (); } Pred_lt_3or6 (st->exc, T0, T0_frac, L_SUBFR, 0); } /*-------------------------------------------------------* * - (MR122 only: Decode pitch gain.) * * - Decode innovative codebook. * * - set pitch sharpening factor * *-------------------------------------------------------*/ if (sub (mode, MR475) == 0 || sub (mode, MR515) == 0) { /* MR475, MR515 */ index = *parm++; /* index of position */ move16 (); i = *parm++; /* signs */ move16 (); decode_2i40_9bits (subfrNr, i, index, code); pit_sharp = shl (st->sharp, 1); } else if (sub (mode, MR59) == 0) { /* MR59 */ test (); index = *parm++; /* index of position */ move16 (); i = *parm++; /* signs */ move16 (); decode_2i40_11bits (i, index, code); pit_sharp = shl (st->sharp, 1); } else if (sub (mode, MR67) == 0) { /* MR67 */ test (); test (); index = *parm++; /* index of position */ move16 (); i = *parm++; /* signs */ move16 (); decode_3i40_14bits (i, index, code); pit_sharp = shl (st->sharp, 1); } else if (sub (mode, MR795) <= 0) { /* MR74, MR795 */ test (); test (); test (); index = *parm++; /* index of position */ move16 (); i = *parm++; /* signs */ move16 (); decode_4i40_17bits (i, index, code); pit_sharp = shl (st->sharp, 1); } else if (sub (mode, MR102) == 0) { /* MR102 */ test (); test (); test (); dec_8i40_31bits (parm, code); parm += 7; move16 (); pit_sharp = shl (st->sharp, 1); } else { /* MR122 */ test (); test (); test (); index = *parm++; move16 (); test(); if (bfi != 0) { ec_gain_pitch (&st->ec_gain_p_st, st->state, &gain_pit); } else { gain_pit = d_gain_pitch (mode, index); move16 (); } ec_gain_pitch_update (&st->ec_gain_p_st, bfi, st->prev_bf, &gain_pit); dec_10i40_35bits (parm, code); parm += 10; move16 (); /* pit_sharp = gain_pit; */ /* if (pit_sharp > 1.0) pit_sharp = 1.0; */ pit_sharp = shl (gain_pit, 1); } /*-------------------------------------------------------* * - Add the pitch contribution to code[]. * *-------------------------------------------------------*/ for (i = T0; i < L_SUBFR; i++) { temp = mult (code[i - T0], pit_sharp); code[i] = add (code[i], temp); move16 (); } /*------------------------------------------------------------* * - Decode codebook gain (MR122) or both pitch * * gain and codebook gain (all others) * * - Update pitch sharpening "sharp" with quantized gain_pit * *------------------------------------------------------------*/ if (test(), sub (mode, MR475) == 0) { /* read and decode pitch and code gain */ test(); if (evenSubfr != 0) { index_mr475 = *parm++; move16 (); /* index of gain(s) */ } test(); if (bfi == 0) { Dec_gain(&st->pred_state, mode, index_mr475, code, evenSubfr, &gain_pit, &gain_code); } else { ec_gain_pitch (&st->ec_gain_p_st, st->state, &gain_pit); ec_gain_code (&st->ec_gain_c_st, &st->pred_state, st->state, &gain_code); } ec_gain_pitch_update (&st->ec_gain_p_st, bfi, st->prev_bf, &gain_pit); ec_gain_code_update (&st->ec_gain_c_st, bfi, st->prev_bf, &gain_code); pit_sharp = gain_pit; move16 (); test (); if (sub (pit_sharp, SHARPMAX) > 0) { pit_sharp = SHARPMAX; move16 (); } } else if (test(), test(), (sub (mode, MR74) <= 0) || (sub (mode, MR102) == 0)) { /* read and decode pitch and code gain */ index = *parm++; move16 (); /* index of gain(s) */ test(); if (bfi == 0) { Dec_gain(&st->pred_state, mode, index, code, evenSubfr, &gain_pit, &gain_code); } else { ec_gain_pitch (&st->ec_gain_p_st, st->state, &gain_pit); ec_gain_code (&st->ec_gain_c_st, &st->pred_state, st->state, &gain_code); } ec_gain_pitch_update (&st->ec_gain_p_st, bfi, st->prev_bf, &gain_pit); ec_gain_code_update (&st->ec_gain_c_st, bfi, st->prev_bf, &gain_code); pit_sharp = gain_pit; move16 (); test (); if (sub (pit_sharp, SHARPMAX) > 0) { pit_sharp = SHARPMAX; move16 (); } if (sub (mode, MR102) == 0) { if (sub (st->old_T0, add(L_SUBFR, 5)) > 0) { pit_sharp = shr(pit_sharp, 2); } } } else { /* read and decode pitch gain */ index = *parm++; move16 (); /* index of gain(s) */ test (); if (sub (mode, MR795) == 0) { /* decode pitch gain */ test(); if (bfi != 0) { ec_gain_pitch (&st->ec_gain_p_st, st->state, &gain_pit); } else { gain_pit = d_gain_pitch (mode, index); move16 (); } ec_gain_pitch_update (&st->ec_gain_p_st, bfi, st->prev_bf, &gain_pit); /* read and decode code gain */ index = *parm++; move16 (); test(); if (bfi == 0) { d_gain_code (&st->pred_state, mode, index, code, &gain_code); } else { ec_gain_code (&st->ec_gain_c_st, &st->pred_state, st->state, &gain_code); } ec_gain_code_update (&st->ec_gain_c_st, bfi, st->prev_bf, &gain_code); pit_sharp = gain_pit; move16 (); test (); if (sub (pit_sharp, SHARPMAX) > 0) { pit_sharp = SHARPMAX; move16 (); } } else { /* MR122 */ test(); if (bfi == 0) { d_gain_code (&st->pred_state, mode, index, code, &gain_code); } else { ec_gain_code (&st->ec_gain_c_st, &st->pred_state, st->state, &gain_code); } ec_gain_code_update (&st->ec_gain_c_st, bfi, st->prev_bf, &gain_code); pit_sharp = gain_pit; move16 (); } } /* store pitch sharpening for next subframe */ /* (for modes which use the previous pitch gain for pitch sharpening in the search phase) */ /* do not update sharpening in even subframes for MR475 */ test(); test(); if (sub(mode, MR475) != 0 || evenSubfr == 0) { st->sharp = gain_pit; move16 (); test (); if (sub (st->sharp, SHARPMAX) > 0) { st->sharp = SHARPMAX; move16 (); } } pit_sharp = shl (pit_sharp, 1); test (); if (sub (pit_sharp, 16384) > 0) { for (i = 0; i < L_SUBFR; i++) { temp = mult (st->exc[i], pit_sharp); L_temp = L_mult (temp, gain_pit); test (); if (sub(mode, MR122)==0) { L_temp = L_shr (L_temp, 1); } excp[i] = round (L_temp); move16 (); } } /*-------------------------------------------------------* * - Store list of LTP gains needed in the source * * characteristic detector (SCD) * *-------------------------------------------------------*/ test (); if ( bfi == 0 ) { for (i = 0; i < 8; i++) { st->ltpGainHistory[i] = st->ltpGainHistory[i+1]; move16 (); } st->ltpGainHistory[8] = gain_pit; move16 (); } /*-------------------------------------------------------* * - Limit gain_pit if in background noise and BFI * * for MR475, MR515, MR59 * *-------------------------------------------------------*/ test (); test (); test (); test (); test (); test (); if ( (st->prev_bf != 0 || bfi != 0) && st->inBackgroundNoise != 0 && ((sub(mode, MR475) == 0) || (sub(mode, MR515) == 0) || (sub(mode, MR59) == 0)) ) { test (); if ( sub (gain_pit, 12288) > 0) /* if (gain_pit > 0.75) in Q14*/ gain_pit = add( shr( sub(gain_pit, 12288), 1 ), 12288 ); /* gain_pit = (gain_pit-0.75)/2.0 + 0.75; */ test (); if ( sub (gain_pit, 14745) > 0) /* if (gain_pit > 0.90) in Q14*/ { gain_pit = 14745; move16 (); } } /*-------------------------------------------------------* * Calculate CB mixed gain * *-------------------------------------------------------*/ Int_lsf(prev_lsf, st->lsfState.past_lsf_q, i_subfr, lsf_i); gain_code_mix = Cb_gain_average( &st->Cb_gain_averState, mode, gain_code, lsf_i, st->lsp_avg_st.lsp_meanSave, bfi, st->prev_bf, pdfi, st->prev_pdf, st->inBackgroundNoise, st->voicedHangover); move16 (); /* make sure that MR74, MR795, MR122 have original code_gain*/ test(); if ((sub(mode, MR67) > 0) && (sub(mode, MR102) != 0) ) /* MR74, MR795, MR122 */ { gain_code_mix = gain_code; move16 (); } /*-------------------------------------------------------* * - Find the total excitation. * * - Find synthesis speech corresponding to st->exc[]. * *-------------------------------------------------------*/ test (); if (sub(mode, MR102) <= 0) /* MR475, MR515, MR59, MR67, MR74, MR795, MR102*/ { pitch_fac = gain_pit; move16 (); tmp_shift = 1; move16 (); } else /* MR122 */ { pitch_fac = shr (gain_pit, 1); move16 (); tmp_shift = 2; move16 (); } /* copy unscaled LTP excitation to exc_enhanced (used in phase * dispersion below) and compute total excitation for LTP feedback */ for (i = 0; i < L_SUBFR; i++) { exc_enhanced[i] = st->exc[i]; move16 (); /* st->exc[i] = gain_pit*st->exc[i] + gain_code*code[i]; */ L_temp = L_mult (st->exc[i], pitch_fac); /* 12.2: Q0 * Q13 */ /* 7.4: Q0 * Q14 */ L_temp = L_mac (L_temp, code[i], gain_code); /* 12.2: Q12 * Q1 */ /* 7.4: Q13 * Q1 */ L_temp = L_shl (L_temp, tmp_shift); /* Q16 */ st->exc[i] = round (L_temp); move16 (); } /*-------------------------------------------------------* * - Adaptive phase dispersion * *-------------------------------------------------------*/ ph_disp_release(&st->ph_disp_st); /* free phase dispersion adaption */ test (); test (); test (); test (); test (); test (); if ( ((sub(mode, MR475) == 0) || (sub(mode, MR515) == 0) || (sub(mode, MR59) == 0)) && sub(st->voicedHangover, 3) > 0 && st->inBackgroundNoise != 0 && bfi != 0 ) { ph_disp_lock(&st->ph_disp_st); /* Always Use full Phase Disp. */ } /* if error in bg noise */ /* apply phase dispersion to innovation (if enabled) and compute total excitation for synthesis part */ ph_disp(&st->ph_disp_st, mode, exc_enhanced, gain_code_mix, gain_pit, code, pitch_fac, tmp_shift); /*-------------------------------------------------------* * - The Excitation control module are active during BFI.* * - Conceal drops in signal energy if in bg noise. * *-------------------------------------------------------*/ L_temp = 0; move32 (); for (i = 0; i < L_SUBFR; i++) { L_temp = L_mac (L_temp, exc_enhanced[i], exc_enhanced[i] ); } L_temp = L_shr (L_temp, 1); /* excEnergy = sqrt(L_temp) in Q0 */ L_temp = sqrt_l_exp(L_temp, &temp); move32 (); /* function result */ L_temp = L_shr(L_temp, add( shr(temp, 1), 15)); L_temp = L_shr(L_temp, 2); /* To cope with 16-bit and */ excEnergy = extract_l(L_temp); /* scaling in ex_ctrl() */ test (); test (); test (); test (); test (); test (); test (); test (); test (); test (); if ( ((sub (mode, MR475) == 0) || (sub (mode, MR515) == 0) || (sub (mode, MR59) == 0)) && sub(st->voicedHangover, 5) > 0 && st->inBackgroundNoise != 0 && sub(st->state, 4) < 0 && ( (pdfi != 0 && st->prev_pdf != 0) || bfi != 0 || st->prev_bf != 0) ) { carefulFlag = 0; move32 (); test (); test (); if ( pdfi != 0 && bfi == 0 ) { carefulFlag = 1; move16 (); } Ex_ctrl(exc_enhanced, excEnergy, st->excEnergyHist, st->voicedHangover, st->prev_bf, carefulFlag); } test (); test (); test (); test (); if ( st->inBackgroundNoise != 0 && ( bfi != 0 || st->prev_bf != 0 ) && sub(st->state, 4) < 0 ) { ; /* do nothing! */ } else { /* Update energy history for all modes */ for (i = 0; i < 8; i++) { st->excEnergyHist[i] = st->excEnergyHist[i+1]; move16 (); } st->excEnergyHist[8] = excEnergy; move16 (); } /*-------------------------------------------------------* * Excitation control module end. * *-------------------------------------------------------*/ test (); if (sub (pit_sharp, 16384) > 0) { for (i = 0; i < L_SUBFR; i++) { excp[i] = add (excp[i], exc_enhanced[i]); move16 (); } agc2 (exc_enhanced, excp, L_SUBFR); Overflow = 0; move16 (); Syn_filt (Az, excp, &synth[i_subfr], L_SUBFR, st->mem_syn, 0); } else { Overflow = 0; move16 (); Syn_filt (Az, exc_enhanced, &synth[i_subfr], L_SUBFR, st->mem_syn, 0); } test (); if (Overflow != 0) /* Test for overflow */ { for (i = 0; i < PIT_MAX + L_INTERPOL + L_SUBFR; i++) { st->old_exc[i] = shr(st->old_exc[i], 2); move16 (); } for (i = 0; i < L_SUBFR; i++) { exc_enhanced[i] = shr(exc_enhanced[i], 2); move16 (); } Syn_filt(Az, exc_enhanced, &synth[i_subfr], L_SUBFR, st->mem_syn, 1); } else { Copy(&synth[i_subfr+L_SUBFR-M], st->mem_syn, M); } /*--------------------------------------------------* * Update signal for next frame. * * -> shift to the left by L_SUBFR st->exc[] * *--------------------------------------------------*/ Copy (&st->old_exc[L_SUBFR], &st->old_exc[0], PIT_MAX + L_INTERPOL); /* interpolated LPC parameters for next subframe */ Az += MP1; move16 (); /* store T0 for next subframe */ st->old_T0 = T0; move16 (); } /*-------------------------------------------------------* * Call the Source Characteristic Detector which updates * * st->inBackgroundNoise and st->voicedHangover. * *-------------------------------------------------------*/ st->inBackgroundNoise = Bgn_scd(&st->background_state, &(st->ltpGainHistory[0]), &(synth[0]), &(st->voicedHangover) ); dtx_dec_activity_update(&st->dtxDecoderState, st->lsfState.past_lsf_q, synth); /* store bfi for next subframe */ st->prev_bf = bfi; move16 (); st->prev_pdf = pdfi; move16 (); /*--------------------------------------------------* * Calculate the LSF averages on the eight * * previous frames * *--------------------------------------------------*/ lsp_avg(&st->lsp_avg_st, st->lsfState.past_lsf_q); the_end: st->dtxDecoderState.dtxGlobalState = newDTXState; return 0; }