FreeCalypso > hg > gsm-codec-lib
view libtwamr/dtx_dec.c @ 417:f17e42c63058
libtwamr: integrate ol_ltp.c
author | Mychaela Falconia <falcon@freecalypso.org> |
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date | Tue, 07 May 2024 03:21:14 +0000 |
parents | 5a1d18542f8a |
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 : dtx_dec.c * Purpose : Decode comfort noise when in DTX * ***************************************************************************** */ /* ***************************************************************************** * MODULE INCLUDE FILE AND VERSION ID ***************************************************************************** */ #include "namespace.h" #include "dtx_dec.h" /* ***************************************************************************** * INCLUDE FILES ***************************************************************************** */ #include "tw_amr.h" #include "typedef.h" #include "basic_op.h" #include "oper_32b.h" #include "memops.h" #include "log2.h" #include "lsp_az.h" #include "pow2.h" #include "a_refl.h" #include "b_cn_cod.h" #include "syn_filt.h" #include "lsp_lsf.h" #include "reorder.h" #include "no_count.h" #include "q_plsf5_tab.h" #include "lsp_tab.h" /* ***************************************************************************** * LOCAL VARIABLES AND TABLES ***************************************************************************** */ #define PN_INITIAL_SEED 0x70816958L /* Pseudo noise generator seed value */ /*************************************************** * Scaling factors for the lsp variability operation * ***************************************************/ static const Word16 lsf_hist_mean_scale[M] = { 20000, 20000, 20000, 20000, 20000, 18000, 16384, 8192, 0, 0 }; /************************************************* * level adjustment for different modes Q11 * *************************************************/ static const Word16 dtx_log_en_adjust[9] = { -1023, /* MR475 */ -878, /* MR515 */ -732, /* MR59 */ -586, /* MR67 */ -440, /* MR74 */ -294, /* MR795 */ -148, /* MR102 */ 0, /* MR122 */ 0, /* MRDTX */ }; /* ***************************************************************************** * PUBLIC PROGRAM CODE ***************************************************************************** */ /* ************************************************************************** * * Function : dtx_dec_reset * ************************************************************************** */ void dtx_dec_reset (dtx_decState *st) { int i; st->since_last_sid = 0; st->true_sid_period_inv = (1 << 13); st->log_en = 3500; st->old_log_en = 3500; /* low level noise for better performance in DTX handover cases*/ st->L_pn_seed_rx = PN_INITIAL_SEED; /* Initialize state->lsp [] and state->lsp_old [] */ Copy(lsp_init_data, &st->lsp[0], M); Copy(lsp_init_data, &st->lsp_old[0], M); st->lsf_hist_ptr = 0; st->log_pg_mean = 0; st->log_en_hist_ptr = 0; /* initialize decoder lsf history */ Copy(mean_lsf, &st->lsf_hist[0], M); for (i = 1; i < DTX_HIST_SIZE; i++) { Copy(&st->lsf_hist[0], &st->lsf_hist[M*i], M); } Set_zero(st->lsf_hist_mean, M*DTX_HIST_SIZE); /* initialize decoder log frame energy */ for (i = 0; i < DTX_HIST_SIZE; i++) { st->log_en_hist[i] = st->log_en; } st->log_en_adjust = 0; st->dtxHangoverCount = DTX_HANG_CONST; st->decAnaElapsedCount = 32767; st->sid_frame = 0; st->valid_data = 0; st->dtxHangoverAdded = 0; st->dtxGlobalState = DTX; st->data_updated = 0; } /* ************************************************************************** * * Function : dtx_dec * ************************************************************************** */ int dtx_dec( dtx_decState *st, /* i/o : State struct */ Word16 mem_syn[], /* i/o : AMR decoder state */ D_plsfState* lsfState, /* i/o : decoder lsf states */ gc_predState* predState, /* i/o : prediction states */ Cb_gain_averageState* averState, /* i/o : CB gain average states */ enum DTXStateType new_state, /* i : new DTX state */ enum Mode mode, /* i : AMR mode */ Word16 parm[], /* i : Vector of synthesis parameters */ Word16 synth[], /* o : synthesised speech */ Word16 A_t[] /* o : decoded LP filter in 4 subframes*/ ) { Word16 log_en_index; Word16 i, j; Word16 int_fac; Word32 L_log_en_int; Word16 lsp_int[M]; Word16 log_en_int_e; Word16 log_en_int_m; Word16 level; Word16 acoeff[M + 1]; Word16 refl[M]; Word16 pred_err; Word16 ex[L_SUBFR]; Word16 ma_pred_init; Word16 log_pg_e, log_pg_m; Word16 log_pg; Flag negative; Word16 lsf_mean; Word32 L_lsf_mean; Word16 lsf_variab_index; Word16 lsf_variab_factor; Word16 lsf_int[M]; Word16 lsf_int_variab[M]; Word16 lsp_int_variab[M]; Word16 acoeff_variab[M + 1]; Word16 lsf[M]; Word32 L_lsf[M]; Word16 ptr; Word16 tmp_int_length; /* This function is called if synthesis state is not SPEECH * the globally passed inputs to this function are * st->sid_frame * st->valid_data * st->dtxHangoverAdded * new_state (SPEECH, DTX, DTX_MUTE) */ test(); test(); if ((st->dtxHangoverAdded != 0) && (st->sid_frame != 0)) { /* sid_first after dtx hangover period */ /* or sid_upd after dtxhangover */ /* set log_en_adjust to correct value */ st->log_en_adjust = dtx_log_en_adjust[mode]; ptr = add(st->lsf_hist_ptr, M); move16(); test(); if (sub(ptr, 80) == 0) { ptr = 0; move16(); } Copy( &st->lsf_hist[st->lsf_hist_ptr],&st->lsf_hist[ptr],M); ptr = add(st->log_en_hist_ptr,1); move16(); test(); if (sub(ptr, DTX_HIST_SIZE) == 0) { ptr = 0; move16(); } move16(); st->log_en_hist[ptr] = st->log_en_hist[st->log_en_hist_ptr]; /* Q11 */ /* compute mean log energy and lsp * * from decoded signal (SID_FIRST) */ st->log_en = 0; move16(); for (i = 0; i < M; i++) { L_lsf[i] = 0; move16(); } /* average energy and lsp */ for (i = 0; i < DTX_HIST_SIZE; i++) { st->log_en = add(st->log_en, shr(st->log_en_hist[i],3)); for (j = 0; j < M; j++) { L_lsf[j] = L_add(L_lsf[j], L_deposit_l(st->lsf_hist[i * M + j])); } } for (j = 0; j < M; j++) { lsf[j] = extract_l(L_shr(L_lsf[j],3)); /* divide by 8 */ move16(); } Lsf_lsp(lsf, st->lsp, M); /* make log_en speech coder mode independent */ /* added again later before synthesis */ st->log_en = sub(st->log_en, st->log_en_adjust); /* compute lsf variability vector */ Copy(st->lsf_hist, st->lsf_hist_mean, 80); for (i = 0; i < M; i++) { L_lsf_mean = 0; move32(); /* compute mean lsf */ for (j = 0; j < 8; j++) { L_lsf_mean = L_add(L_lsf_mean, L_deposit_l(st->lsf_hist_mean[i+j*M])); } lsf_mean = extract_l(L_shr(L_lsf_mean, 3)); move16(); /* subtract mean and limit to within reasonable limits * * moreover the upper lsf's are attenuated */ for (j = 0; j < 8; j++) { /* subtract mean */ st->lsf_hist_mean[i+j*M] = sub(st->lsf_hist_mean[i+j*M], lsf_mean); /* attenuate deviation from mean, especially for upper lsf's */ st->lsf_hist_mean[i+j*M] = mult(st->lsf_hist_mean[i+j*M], lsf_hist_mean_scale[i]); /* limit the deviation */ test(); if (st->lsf_hist_mean[i+j*M] < 0) { negative = 1; move16(); } else { negative = 0; move16(); } st->lsf_hist_mean[i+j*M] = abs_s(st->lsf_hist_mean[i+j*M]); /* apply soft limit */ test(); if (sub(st->lsf_hist_mean[i+j*M], 655) > 0) { st->lsf_hist_mean[i+j*M] = add(655, shr(sub(st->lsf_hist_mean[i+j*M], 655), 2)); } /* apply hard limit */ test(); if (sub(st->lsf_hist_mean[i+j*M], 1310) > 0) { st->lsf_hist_mean[i+j*M] = 1310; move16(); } test(); if (negative != 0) { st->lsf_hist_mean[i+j*M] = -st->lsf_hist_mean[i+j*M];move16(); } } } } test(); if (st->sid_frame != 0 ) { /* Set old SID parameters, always shift */ /* even if there is no new valid_data */ Copy(st->lsp, st->lsp_old, M); st->old_log_en = st->log_en; move16(); test(); if (st->valid_data != 0 ) /* new data available (no CRC) */ { /* Compute interpolation factor, since the division only works * * for values of since_last_sid < 32 we have to limit the * * interpolation to 32 frames */ tmp_int_length = st->since_last_sid; move16(); st->since_last_sid = 0; move16(); test(); if (sub(tmp_int_length, 32) > 0) { tmp_int_length = 32; move16(); } test(); if (sub(tmp_int_length, 2) >= 0) { move16(); st->true_sid_period_inv = div_s(1 << 10, shl(tmp_int_length, 10)); } else { st->true_sid_period_inv = 1 << 14; /* 0.5 it Q15 */ move16(); } Init_D_plsf_3(lsfState, parm[0]); /* temporay initialization */ D_plsf_3(lsfState, MRDTX, 0, &parm[1], st->lsp); Set_zero(lsfState->past_r_q, M); /* reset for next speech frame */ log_en_index = parm[4]; move16(); /* Q11 and divide by 4 */ st->log_en = shl(log_en_index, (11 - 2)); move16(); /* Subtract 2.5 in Q11 */ st->log_en = sub(st->log_en, (2560 * 2)); /* Index 0 is reserved for silence */ test(); if (log_en_index == 0) { st->log_en = MIN_16; move16(); } /* no interpolation at startup after coder reset */ /* or when SID_UPD has been received right after SPEECH */ test(); test(); if ((st->data_updated == 0) || (sub(st->dtxGlobalState, SPEECH) == 0) ) { Copy(st->lsp, st->lsp_old, M); st->old_log_en = st->log_en; move16(); } } /* endif valid_data */ /* initialize gain predictor memory of other modes */ ma_pred_init = sub(shr(st->log_en,1), 9000); move16(); test(); if (ma_pred_init > 0) { ma_pred_init = 0; move16(); } test(); if (sub(ma_pred_init, -14436) < 0) { ma_pred_init = -14436; move16(); } predState->past_qua_en[0] = ma_pred_init; move16(); predState->past_qua_en[1] = ma_pred_init; move16(); predState->past_qua_en[2] = ma_pred_init; move16(); predState->past_qua_en[3] = ma_pred_init; move16(); /* past_qua_en for other modes than MR122 */ ma_pred_init = mult(5443, ma_pred_init); /* scale down by factor 20*log10(2) in Q15 */ predState->past_qua_en_MR122[0] = ma_pred_init; move16(); predState->past_qua_en_MR122[1] = ma_pred_init; move16(); predState->past_qua_en_MR122[2] = ma_pred_init; move16(); predState->past_qua_en_MR122[3] = ma_pred_init; move16(); } /* endif sid_frame */ /* CN generation */ /* recompute level adjustment factor Q11 * * st->log_en_adjust = 0.9*st->log_en_adjust + * * 0.1*dtx_log_en_adjust[mode]); */ move16(); st->log_en_adjust = add(mult(st->log_en_adjust, 29491), shr(mult(shl(dtx_log_en_adjust[mode],5),3277),5)); /* Interpolate SID info */ int_fac = shl(add(1,st->since_last_sid), 10); /* Q10 */ move16(); int_fac = mult(int_fac, st->true_sid_period_inv); /* Q10 * Q15 -> Q10 */ /* Maximize to 1.0 in Q10 */ test(); if (sub(int_fac, 1024) > 0) { int_fac = 1024; move16(); } int_fac = shl(int_fac, 4); /* Q10 -> Q14 */ L_log_en_int = L_mult(int_fac, st->log_en); /* Q14 * Q11->Q26 */ move32(); for(i = 0; i < M; i++) { lsp_int[i] = mult(int_fac, st->lsp[i]);/* Q14 * Q15 -> Q14 */ move16(); } int_fac = sub(16384, int_fac); /* 1-k in Q14 */ move16(); /* (Q14 * Q11 -> Q26) + Q26 -> Q26 */ L_log_en_int = L_mac(L_log_en_int, int_fac, st->old_log_en); for(i = 0; i < M; i++) { /* Q14 + (Q14 * Q15 -> Q14) -> Q14 */ lsp_int[i] = add(lsp_int[i], mult(int_fac, st->lsp_old[i])); move16(); lsp_int[i] = shl(lsp_int[i], 1); /* Q14 -> Q15 */ move16(); } /* compute the amount of lsf variability */ lsf_variab_factor = sub(st->log_pg_mean,2457); /* -0.6 in Q12 */ move16(); /* *0.3 Q12*Q15 -> Q12 */ lsf_variab_factor = sub(4096, mult(lsf_variab_factor, 9830)); /* limit to values between 0..1 in Q12 */ test(); if (sub(lsf_variab_factor, 4096) > 0) { lsf_variab_factor = 4096; move16(); } test(); if (lsf_variab_factor < 0) { lsf_variab_factor = 0; move16(); } lsf_variab_factor = shl(lsf_variab_factor, 3); /* -> Q15 */ move16(); /* get index of vector to do variability with */ lsf_variab_index = pseudonoise(&st->L_pn_seed_rx, 3); move16(); /* convert to lsf */ Lsp_lsf(lsp_int, lsf_int, M); /* apply lsf variability */ Copy(lsf_int, lsf_int_variab, M); for(i = 0; i < M; i++) { move16(); lsf_int_variab[i] = add(lsf_int_variab[i], mult(lsf_variab_factor, st->lsf_hist_mean[i+lsf_variab_index*M])); } /* make sure that LSP's are ordered */ Reorder_lsf(lsf_int, LSF_GAP, M); Reorder_lsf(lsf_int_variab, LSF_GAP, M); /* copy lsf to speech decoders lsf state */ Copy(lsf_int, lsfState->past_lsf_q, M); /* convert to lsp */ Lsf_lsp(lsf_int, lsp_int, M); Lsf_lsp(lsf_int_variab, lsp_int_variab, M); /* Compute acoeffs Q12 acoeff is used for level * * normalization and postfilter, acoeff_variab is * * used for synthesis filter * * by doing this we make sure that the level * * in high frequenncies does not jump up and down */ Lsp_Az(lsp_int, acoeff); Lsp_Az(lsp_int_variab, acoeff_variab); /* For use in postfilter */ Copy(acoeff, &A_t[0], M + 1); Copy(acoeff, &A_t[M + 1], M + 1); Copy(acoeff, &A_t[2 * (M + 1)], M + 1); Copy(acoeff, &A_t[3 * (M + 1)], M + 1); /* Compute reflection coefficients Q15 */ A_Refl(&acoeff[1], refl); /* Compute prediction error in Q15 */ pred_err = MAX_16; /* 0.99997 in Q15 */ move16(); for (i = 0; i < M; i++) { pred_err = mult(pred_err, sub(MAX_16, mult(refl[i], refl[i]))); } /* compute logarithm of prediction gain */ Log2(L_deposit_l(pred_err), &log_pg_e, &log_pg_m); /* convert exponent and mantissa to Word16 Q12 */ log_pg = shl(sub(log_pg_e,15), 12); /* Q12 */ move16(); log_pg = shr(sub(0,add(log_pg, shr(log_pg_m, 15-12))), 1); move16(); st->log_pg_mean = add(mult(29491,st->log_pg_mean), mult(3277, log_pg)); move16(); /* Compute interpolated log energy */ L_log_en_int = L_shr(L_log_en_int, 10); /* Q26 -> Q16 */ move32(); /* Add 4 in Q16 */ L_log_en_int = L_add(L_log_en_int, 4 * 65536L); move32(); /* subtract prediction gain */ L_log_en_int = L_sub(L_log_en_int, L_shl(L_deposit_l(log_pg), 4));move32(); /* adjust level to speech coder mode */ L_log_en_int = L_add(L_log_en_int, L_shl(L_deposit_l(st->log_en_adjust), 5)); move32(); log_en_int_e = extract_h(L_log_en_int); move16(); move16(); log_en_int_m = extract_l(L_shr(L_sub(L_log_en_int, L_deposit_h(log_en_int_e)), 1)); level = extract_l(Pow2(log_en_int_e, log_en_int_m)); /* Q4 */ move16(); for (i = 0; i < 4; i++) { /* Compute innovation vector */ build_CN_code(&st->L_pn_seed_rx, ex); for (j = 0; j < L_SUBFR; j++) { ex[j] = mult(level, ex[j]); move16(); } /* Synthesize */ Syn_filt(acoeff_variab, ex, &synth[i * L_SUBFR], L_SUBFR, mem_syn, 1); } /* next i */ /* reset codebook averaging variables */ averState->hangVar = 20; move16(); averState->hangCount = 0; move16(); test(); if (sub(new_state, DTX_MUTE) == 0) { /* mute comfort noise as it has been quite a long time since * last SID update was performed */ tmp_int_length = st->since_last_sid; move16(); test(); if (sub(tmp_int_length, 32) > 0) { tmp_int_length = 32; move16(); } /* safety guard against division by zero */ test(); if(tmp_int_length <= 0) { tmp_int_length = 8; move16(); } move16(); st->true_sid_period_inv = div_s(1 << 10, shl(tmp_int_length, 10)); st->since_last_sid = 0; move16(); Copy(st->lsp, st->lsp_old, M); st->old_log_en = st->log_en; move16(); /* subtract 1/8 in Q11 i.e -6/8 dB */ st->log_en = sub(st->log_en, 256); move16(); } /* reset interpolation length timer * if data has been updated. */ test(); test(); test(); test(); if ((st->sid_frame != 0) && ((st->valid_data != 0) || ((st->valid_data == 0) && (st->dtxHangoverAdded) != 0))) { st->since_last_sid = 0; move16(); st->data_updated = 1; move16(); } return 0; } void dtx_dec_activity_update(dtx_decState *st, Word16 lsf[], Word16 frame[]) { Word16 i; Word32 L_frame_en; Word16 log_en_e, log_en_m, log_en; /* update lsp history */ st->lsf_hist_ptr = add(st->lsf_hist_ptr,M); move16(); test(); if (sub(st->lsf_hist_ptr, 80) == 0) { st->lsf_hist_ptr = 0; move16(); } Copy(lsf, &st->lsf_hist[st->lsf_hist_ptr], M); /* compute log energy based on frame energy */ L_frame_en = 0; /* Q0 */ move32(); for (i=0; i < L_FRAME; i++) { L_frame_en = L_mac(L_frame_en, frame[i], frame[i]); } Log2(L_frame_en, &log_en_e, &log_en_m); /* convert exponent and mantissa to Word16 Q10 */ log_en = shl(log_en_e, 10); /* Q10 */ log_en = add(log_en, shr(log_en_m, 15-10)); /* divide with L_FRAME i.e subtract with log2(L_FRAME) = 7.32193 */ log_en = sub(log_en, 7497+1024); /* insert into log energy buffer, no division by two as * * log_en in decoder is Q11 */ st->log_en_hist_ptr = add(st->log_en_hist_ptr, 1); test(); if (sub(st->log_en_hist_ptr, DTX_HIST_SIZE) == 0) { st->log_en_hist_ptr = 0; move16(); } st->log_en_hist[st->log_en_hist_ptr] = log_en; /* Q11 */ move16(); } /* Table of new SPD synthesis states | previous SPD_synthesis_state Incoming | frame_type | SPEECH | DTX | DTX_MUTE --------------------------------------------------------------- RX_SPEECH_GOOD , | | | RX_SPEECH_PR_DEGRADED | SPEECH | SPEECH | SPEECH ---------------------------------------------------------------- RX_SPEECH_BAD, | SPEECH | DTX | DTX_MUTE ---------------------------------------------------------------- RX_SID_FIRST, | DTX | DTX/(DTX_MUTE)| DTX_MUTE ---------------------------------------------------------------- RX_SID_UPDATE, | DTX | DTX | DTX ---------------------------------------------------------------- RX_SID_BAD, | DTX | DTX/(DTX_MUTE)| DTX_MUTE ---------------------------------------------------------------- RX_NO_DATA | SPEECH | DTX/(DTX_MUTE)| DTX_MUTE |(class2 garb.)| | ---------------------------------------------------------------- RX_ONSET | SPEECH | DTX/(DTX_MUTE)| DTX_MUTE |(class2 garb.)| | ---------------------------------------------------------------- */ enum DTXStateType rx_dtx_handler( dtx_decState *st, /* i/o : State struct */ enum RXFrameType frame_type /* i : Frame type */ ) { enum DTXStateType newState; enum DTXStateType encState; /* DTX if SID frame or previously in DTX{_MUTE} and (NO_RX OR BAD_SPEECH) */ test(); test(); test(); test(); test(); test(); test(); test(); if ((sub(frame_type, RX_SID_FIRST) == 0) || (sub(frame_type, RX_SID_UPDATE) == 0) || (sub(frame_type, RX_SID_BAD) == 0) || (((sub(st->dtxGlobalState, DTX) == 0) || (sub(st->dtxGlobalState, DTX_MUTE) == 0)) && ((sub(frame_type, RX_NO_DATA) == 0) || (sub(frame_type, RX_SPEECH_BAD) == 0) || (sub(frame_type, RX_ONSET) == 0)))) { newState = DTX; move16(); /* stay in mute for these input types */ test(); test(); test(); test(); test(); if ((sub(st->dtxGlobalState, DTX_MUTE) == 0) && ((sub(frame_type, RX_SID_BAD) == 0) || (sub(frame_type, RX_SID_FIRST) == 0) || (sub(frame_type, RX_ONSET) == 0) || (sub(frame_type, RX_NO_DATA) == 0))) { newState = DTX_MUTE; move16(); } /* evaluate if noise parameters are too old */ /* since_last_sid is reset when CN parameters have been updated */ st->since_last_sid = add(st->since_last_sid, 1); move16(); /* no update of sid parameters in DTX for a long while */ /* Due to the delayed update of st->since_last_sid counter SID_UPDATE frames need to be handled separately to avoid entering DTX_MUTE for late SID_UPDATE frames */ test(); test(); logic16(); if((sub(frame_type, RX_SID_UPDATE) != 0) && (sub(st->since_last_sid, DTX_MAX_EMPTY_THRESH) > 0)) { newState = DTX_MUTE; move16(); } } else { newState = SPEECH; move16(); st->since_last_sid = 0; move16(); } /* reset the decAnaElapsed Counter when receiving CNI data the first time, to robustify counter missmatch after handover this might delay the bwd CNI analysis in the new decoder slightly. */ test(); test(); if ((st->data_updated == 0) && (sub(frame_type, RX_SID_UPDATE) == 0)) { st->decAnaElapsedCount = 0; move16(); } /* update the SPE-SPD DTX hangover synchronization */ /* to know when SPE has added dtx hangover */ st->decAnaElapsedCount = add(st->decAnaElapsedCount, 1); move16(); st->dtxHangoverAdded = 0; move16(); test(); test(); test(); test(); test(); if ((sub(frame_type, RX_SID_FIRST) == 0) || (sub(frame_type, RX_SID_UPDATE) == 0) || (sub(frame_type, RX_SID_BAD) == 0) || (sub(frame_type, RX_ONSET) == 0) || (sub(frame_type, RX_NO_DATA) == 0)) { encState = DTX; move16(); /* In frame errors simulations RX_NO_DATA may occasionally mean that a speech packet was probably sent by the encoder, the assumed _encoder_ state should be SPEECH in such cases. */ test(); logic16(); if((sub(frame_type, RX_NO_DATA) == 0) && (sub(newState, SPEECH) == 0)) { encState = SPEECH; move16(); } /* Note on RX_ONSET operation differing from RX_NO_DATA operation: If a RX_ONSET is received in the decoder (by "accident") it is still most likely that the encoder state for the "ONSET frame" was DTX. */ } else { encState = SPEECH; move16(); } test(); if (sub(encState, SPEECH) == 0) { st->dtxHangoverCount = DTX_HANG_CONST; move16(); } else { test(); if (sub(st->decAnaElapsedCount, DTX_ELAPSED_FRAMES_THRESH) > 0) { st->dtxHangoverAdded = 1; move16(); st->decAnaElapsedCount = 0; move16(); st->dtxHangoverCount = 0; move16(); } else if (test(), st->dtxHangoverCount == 0) { st->decAnaElapsedCount = 0; move16(); } else { st->dtxHangoverCount = sub(st->dtxHangoverCount, 1); move16(); } } if (sub(newState, SPEECH) != 0) { /* DTX or DTX_MUTE * CN data is not in a first SID, first SIDs are marked as SID_BAD * but will do backwards analysis if a hangover period has been added * according to the state machine above */ st->sid_frame = 0; move16(); st->valid_data = 0; move16(); test(); if (sub(frame_type, RX_SID_FIRST) == 0) { st->sid_frame = 1; move16(); } else if (test(), sub(frame_type, RX_SID_UPDATE) == 0) { st->sid_frame = 1; move16(); st->valid_data = 1; move16(); } else if (test(), sub(frame_type, RX_SID_BAD) == 0) { st->sid_frame = 1; move16(); st->dtxHangoverAdded = 0; /* use old data */ move16(); } } return newState; /* newState is used by both SPEECH AND DTX synthesis routines */ }