FreeCalypso > hg > gsm-codec-lib
view libgsmefr/d_plsf_5.c @ 183:452c1d5a6268
libgsmefr BFI w/o data: emit zero output after decoder reset
In real-life usage, each EFR decoder session will most likely begin
with lots of BFI frames before the first real frame arrives. However,
because the spec-defined home state of the decoder is speech rather
than CN, our regular logic for BFI w/o data would have to feed
pseudorandom noise to the decoder (in the "fixed codebook excitation
pulses" part), which is silly to do at the beginning of the decoder
session right out of reset. Therefore, let's check reset_flag_old,
and if we are still in the reset state, simply emit zero output.
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Tue, 03 Jan 2023 00:12:18 +0000 |
parents | cc08498ed21b |
children |
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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; }