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view libtwamr/dtx_enc.c @ 509:b7ddcb178ef6 default tip
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author | Mychaela Falconia <falcon@freecalypso.org> |
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date | Sat, 17 Aug 2024 23:11:51 +0000 |
parents | 5a1d18542f8a |
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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_enc.c * Purpose : DTX mode computation of SID parameters * ******************************************************************************** */ /* ******************************************************************************** * MODULE INCLUDE FILE AND VERSION ID ******************************************************************************** */ #include "namespace.h" #include "dtx_enc.h" /* ******************************************************************************** * INCLUDE FILES ******************************************************************************** */ #include "tw_amr.h" #include "typedef.h" #include "basic_op.h" #include "oper_32b.h" #include "q_plsf.h" #include "memops.h" #include "log2.h" #include "lsp_lsf.h" #include "reorder.h" #include "no_count.h" #include "lsp_tab.h" /* ******************************************************************************** * PUBLIC PROGRAM CODE ******************************************************************************** */ /* ************************************************************************** * * Function : dtx_enc_reset * ************************************************************************** */ void dtx_enc_reset (dtx_encState *st) { Word16 i; st->hist_ptr = 0; st->log_en_index = 0; st->init_lsf_vq_index = 0; st->lsp_index[0] = 0; st->lsp_index[1] = 0; st->lsp_index[2] = 0; /* Init lsp_hist[] */ for(i = 0; i < DTX_HIST_SIZE; i++) { Copy(lsp_init_data, &st->lsp_hist[i * M], M); } /* Reset energy history */ Set_zero(st->log_en_hist, M); st->dtxHangoverCount = DTX_HANG_CONST; st->decAnaElapsedCount = 32767; } /* ************************************************************************** * * Function : dtx_enc * ************************************************************************** */ int dtx_enc(dtx_encState *st, /* i/o : State struct */ Word16 computeSidFlag, /* i : compute SID */ Q_plsfState *qSt, /* i/o : Qunatizer state struct */ gc_predState* predState, /* i/o : State struct */ Word16 **anap /* o : analysis parameters */ ) { Word16 i,j; Word16 log_en; Word16 lsf[M]; Word16 lsp[M]; Word16 lsp_q[M]; Word32 L_lsp[M]; /* VOX mode computation of SID parameters */ test (); test (); if ((computeSidFlag != 0)) { /* compute new SID frame if safe i.e don't * compute immediately after a talk spurt */ log_en = 0; move16 (); for (i = 0; i < M; i++) { L_lsp[i] = 0; move16 (); } /* average energy and lsp */ for (i = 0; i < DTX_HIST_SIZE; i++) { log_en = add(log_en, shr(st->log_en_hist[i],2)); for (j = 0; j < M; j++) { L_lsp[j] = L_add(L_lsp[j], L_deposit_l(st->lsp_hist[i * M + j])); } } log_en = shr(log_en, 1); for (j = 0; j < M; j++) { lsp[j] = extract_l(L_shr(L_lsp[j], 3)); /* divide by 8 */ } /* quantize logarithmic energy to 6 bits */ st->log_en_index = add(log_en, 2560); /* +2.5 in Q10 */ st->log_en_index = add(st->log_en_index, 128); /* add 0.5/4 in Q10 */ st->log_en_index = shr(st->log_en_index, 8); test (); if (sub(st->log_en_index, 63) > 0) { st->log_en_index = 63; move16 (); } test (); if (st->log_en_index < 0) { st->log_en_index = 0; move16 (); } /* update gain predictor memory */ log_en = shl(st->log_en_index, -2+10); /* Q11 and divide by 4 */ log_en = sub(log_en, 2560); /* add 2.5 in Q11 */ log_en = sub(log_en, 9000); test (); if (log_en > 0) { log_en = 0; move16 (); } test (); if (sub(log_en, -14436) < 0) { log_en = -14436; move16 (); } /* past_qua_en for other modes than MR122 */ predState->past_qua_en[0] = log_en; move16 (); predState->past_qua_en[1] = log_en; move16 (); predState->past_qua_en[2] = log_en; move16 (); predState->past_qua_en[3] = log_en; move16 (); /* scale down by factor 20*log10(2) in Q15 */ log_en = mult(5443, log_en); /* past_qua_en for mode MR122 */ predState->past_qua_en_MR122[0] = log_en; move16 (); predState->past_qua_en_MR122[1] = log_en; move16 (); predState->past_qua_en_MR122[2] = log_en; move16 (); predState->past_qua_en_MR122[3] = log_en; move16 (); /* make sure that LSP's are ordered */ Lsp_lsf(lsp, lsf, M); Reorder_lsf(lsf, LSF_GAP, M); Lsf_lsp(lsf, lsp, M); /* Quantize lsp and put on parameter list */ Q_plsf_3(qSt, MRDTX, lsp, lsp_q, st->lsp_index, &st->init_lsf_vq_index); } *(*anap)++ = st->init_lsf_vq_index; /* 3 bits */ move16 (); *(*anap)++ = st->lsp_index[0]; /* 8 bits */ move16 (); *(*anap)++ = st->lsp_index[1]; /* 9 bits */ move16 (); *(*anap)++ = st->lsp_index[2]; /* 9 bits */ move16 (); *(*anap)++ = st->log_en_index; /* 6 bits */ move16 (); /* = 35 bits */ return 0; } /* ************************************************************************** * * Function : dtx_buffer * Purpose : handles the DTX buffer * ************************************************************************** */ int dtx_buffer(dtx_encState *st, /* i/o : State struct */ Word16 lsp_new[], /* i : LSP vector */ Word16 speech[] /* i : speech samples */ ) { Word16 i; Word32 L_frame_en; Word16 log_en_e; Word16 log_en_m; Word16 log_en; /* update pointer to circular buffer */ st->hist_ptr = add(st->hist_ptr, 1); test (); if (sub(st->hist_ptr, DTX_HIST_SIZE) == 0) { st->hist_ptr = 0; move16 (); } /* copy lsp vector into buffer */ Copy(lsp_new, &st->lsp_hist[st->hist_ptr * M], 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, speech[i], speech[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, 8521); /* insert into log energy buffer with division by 2 */ log_en = shr(log_en, 1); st->log_en_hist[st->hist_ptr] = log_en; /* Q10 */ move16 (); return 0; } /* ************************************************************************** * * Function : tx_dtx_handler * Purpose : adds extra speech hangover to analyze speech on the decoding side. * ************************************************************************** */ Word16 tx_dtx_handler(dtx_encState *st, /* i/o : State struct */ Word16 vad_flag, /* i : vad decision */ enum Mode *usedMode /* i/o : mode changed or not */ ) { Word16 compute_new_sid_possible; /* this state machine is in synch with the GSMEFR txDtx machine */ st->decAnaElapsedCount = add(st->decAnaElapsedCount, 1); compute_new_sid_possible = 0; move16(); test(); if (vad_flag != 0) { st->dtxHangoverCount = DTX_HANG_CONST; move16(); } else { /* non-speech */ test(); if (st->dtxHangoverCount == 0) { /* out of decoder analysis hangover */ st->decAnaElapsedCount = 0; move16(); *usedMode = MRDTX; move16(); compute_new_sid_possible = 1; move16(); } else { /* in possible analysis hangover */ st->dtxHangoverCount = sub(st->dtxHangoverCount, 1); /* decAnaElapsedCount + dtxHangoverCount < DTX_ELAPSED_FRAMES_THRESH */ test (); if (sub(add(st->decAnaElapsedCount, st->dtxHangoverCount), DTX_ELAPSED_FRAMES_THRESH) < 0) { *usedMode = MRDTX; move16(); /* if short time since decoder update, do not add extra HO */ } /* else override VAD and stay in speech mode *usedMode and add extra hangover */ } } return compute_new_sid_possible; }