FreeCalypso > hg > gsm-codec-lib
view libgsmefr/d_plsf_5.c @ 467:ad032051166a
doc: AMR-EFR-hybrid-emu new article
author | Mychaela Falconia <falcon@freecalypso.org> |
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date | Sun, 12 May 2024 23:54:43 +0000 |
parents | cc08498ed21b |
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/************************************************************************* * * FUNCTION: D_plsf_5() * * PURPOSE: Decodes the 2 sets of LSP parameters in a frame using the * received quantization indices. * * DESCRIPTION: * The two sets of LSFs are quantized using split by 5 matrix * quantization (split-MQ) with 1st order MA prediction. * * See "q_plsf_5.c" for more details about the quantization procedure * *************************************************************************/ #include "gsm_efr.h" #include "typedef.h" #include "namespace.h" #include "basic_op.h" #include "no_count.h" #include "codec.h" #include "sig_proc.h" #include "memops.h" #include "q_plsf5_tab.h" /* Codebooks of LSF prediction residual */ #include "cnst.h" #include "dtx.h" #include "dec_state.h" /* M ->order of linear prediction filter */ /* LSF_GAP -> Minimum distance between LSF after quantization */ /* 50 Hz = 205 */ /* PRED_FAC -> Prediction factor = 0.65 */ /* ALPHA -> 0.9 */ /* ONE_ALPHA-> (1.0-ALPHA) */ #define M 10 #define LSF_GAP 205 #define PRED_FAC 21299 #define ALPHA 31128 #define ONE_ALPHA 1639 void D_plsf_5 ( struct EFR_decoder_state *st, const Word16 *indice, /* input : quantization indices of 5 submatrices */ Word16 *lsp1_q, /* output: quantized 1st LSP vector */ Word16 *lsp2_q, /* output: quantized 2nd LSP vector */ Word16 bfi, /* input : bad frame indicator (set to 1 if a bad frame is received) */ Word16 rxdtx_ctrl, /* input : RX DTX control word */ Word16 rx_dtx_state /* input : state of the comfort noise insertion period */ ) { Word16 i; const Word16 *p_dico; Word16 temp, sign; Word16 lsf1_r[M], lsf2_r[M]; Word16 lsf1_q[M], lsf2_q[M]; /* Update comfort noise LSF quantizer memory */ if ((rxdtx_ctrl & RX_UPD_SID_QUANT_MEM) != 0) { update_lsf_p_CN (st->lsf_old_rx, st->lsf_p_CN); } /* Handle cases of comfort noise LSF decoding in which past valid SID frames are repeated */ if (((rxdtx_ctrl & RX_NO_TRANSMISSION) != 0) || ((rxdtx_ctrl & RX_INVALID_SID_FRAME) != 0) || ((rxdtx_ctrl & RX_LOST_SID_FRAME) != 0)) { if ((rxdtx_ctrl & RX_NO_TRANSMISSION) != 0) { /* DTX active: no transmission. Interpolate LSF values in memory */ interpolate_CN_lsf (st->lsf_old_CN, st->lsf_new_CN, lsf2_q, rx_dtx_state); } else { /* Invalid or lost SID frame: use LSFs from last good SID frame */ for (i = 0; i < M; i++) { st->lsf_old_CN[i] = st->lsf_new_CN[i]; lsf2_q[i] = st->lsf_new_CN[i]; st->past_r2_q[i] = 0; } } for (i = 0; i < M; i++) { st->past_lsf_q[i] = lsf2_q[i]; } /* convert LSFs to the cosine domain */ Lsf_lsp (lsf2_q, lsp2_q, M); return; } if (bfi != 0) /* if bad frame */ { /* use the past LSFs slightly shifted towards their mean */ for (i = 0; i < M; i++) { /* lsfi_q[i] = ALPHA*past_lsf_q[i] + ONE_ALPHA*mean_lsf[i]; */ lsf1_q[i] = add (mult (st->past_lsf_q[i], ALPHA), mult (mean_lsf[i], ONE_ALPHA)); lsf2_q[i] = lsf1_q[i]; } /* estimate past quantized residual to be used in next frame */ for (i = 0; i < M; i++) { /* temp = mean_lsf[i] + past_r2_q[i] * PRED_FAC; */ temp = add (mean_lsf[i], mult (st->past_r2_q[i], PRED_FAC)); st->past_r2_q[i] = sub (lsf2_q[i], temp); } } else /* if good LSFs received */ { /* decode prediction residuals from 5 received indices */ p_dico = &dico1_lsf[shl (indice[0], 2)]; lsf1_r[0] = *p_dico++; move16 (); lsf1_r[1] = *p_dico++; move16 (); lsf2_r[0] = *p_dico++; move16 (); lsf2_r[1] = *p_dico++; move16 (); p_dico = &dico2_lsf[shl (indice[1], 2)]; lsf1_r[2] = *p_dico++; move16 (); lsf1_r[3] = *p_dico++; move16 (); lsf2_r[2] = *p_dico++; move16 (); lsf2_r[3] = *p_dico++; move16 (); sign = indice[2] & 1; logic16 (); i = shr (indice[2], 1); p_dico = &dico3_lsf[shl (i, 2)]; move16 (); test (); if (sign == 0) { lsf1_r[4] = *p_dico++; move16 (); lsf1_r[5] = *p_dico++; move16 (); lsf2_r[4] = *p_dico++; move16 (); lsf2_r[5] = *p_dico++; move16 (); } else { lsf1_r[4] = negate (*p_dico++); move16 (); lsf1_r[5] = negate (*p_dico++); move16 (); lsf2_r[4] = negate (*p_dico++); move16 (); lsf2_r[5] = negate (*p_dico++); move16 (); } p_dico = &dico4_lsf[shl (indice[3], 2)];move16 (); lsf1_r[6] = *p_dico++; move16 (); lsf1_r[7] = *p_dico++; move16 (); lsf2_r[6] = *p_dico++; move16 (); lsf2_r[7] = *p_dico++; move16 (); p_dico = &dico5_lsf[shl (indice[4], 2)];move16 (); lsf1_r[8] = *p_dico++; move16 (); lsf1_r[9] = *p_dico++; move16 (); lsf2_r[8] = *p_dico++; move16 (); lsf2_r[9] = *p_dico++; move16 (); /* Compute quantized LSFs and update the past quantized residual */ /* Use lsf_p_CN as predicted LSF vector in case of no speech activity */ if ((rxdtx_ctrl & RX_SP_FLAG) != 0) { for (i = 0; i < M; i++) { temp = add (mean_lsf[i], mult (st->past_r2_q[i], PRED_FAC)); lsf1_q[i] = add (lsf1_r[i], temp); lsf2_q[i] = add (lsf2_r[i], temp); st->past_r2_q[i] = lsf2_r[i]; } } else { /* Valid SID frame */ for (i = 0; i < M; i++) { lsf2_q[i] = add (lsf2_r[i], st->lsf_p_CN[i]); /* Use the dequantized values of lsf2 also for lsf1 */ lsf1_q[i] = lsf2_q[i]; st->past_r2_q[i] = 0; } } } /* verification that LSFs have minimum distance of LSF_GAP Hz */ Reorder_lsf (lsf1_q, LSF_GAP, M); Reorder_lsf (lsf2_q, LSF_GAP, M); if ((rxdtx_ctrl & RX_FIRST_SID_UPDATE) != 0) { for (i = 0; i < M; i++) { st->lsf_new_CN[i] = lsf2_q[i]; } } if ((rxdtx_ctrl & RX_CONT_SID_UPDATE) != 0) { for (i = 0; i < M; i++) { st->lsf_old_CN[i] = st->lsf_new_CN[i]; st->lsf_new_CN[i] = lsf2_q[i]; } } if ((rxdtx_ctrl & RX_SP_FLAG) != 0) { /* Update lsf history with quantized LSFs when speech activity is present. If the current frame is a bad one, update with most recent good comfort noise LSFs */ if (bfi==0) { update_lsf_history (lsf1_q, lsf2_q, st->lsf_old_rx); } else { update_lsf_history (st->lsf_new_CN, st->lsf_new_CN, st->lsf_old_rx); } for (i = 0; i < M; i++) { st->lsf_old_CN[i] = lsf2_q[i]; } } else { interpolate_CN_lsf (st->lsf_old_CN, st->lsf_new_CN, lsf2_q, rx_dtx_state); } for (i = 0; i < M; i++) { st->past_lsf_q[i] = lsf2_q[i]; } /* convert LSFs to the cosine domain */ Lsf_lsp (lsf1_q, lsp1_q, M); Lsf_lsp (lsf2_q, lsp2_q, M); return; }