FreeCalypso > hg > gsm-codec-lib
view libgsmefr/q_plsf_5.c @ 581:e2d5cad04cbf
libgsmhr1 RxFE: store CN R0+LPC separately from speech
In the original GSM 06.06 code the ECU for speech mode is entirely
separate from the CN generator, maintaining separate state. (The
main intertie between them is the speech vs CN state variable,
distinguishing between speech and CN BFIs, in addition to the
CN-specific function of distinguishing between initial and update
SIDs.)
In the present RxFE implementation I initially thought that we could
use the same saved_frame buffer for both ECU and CN, overwriting
just the first 4 params (R0 and LPC) when a valid SID comes in.
However, I now realize it was a bad idea: the original code has a
corner case (long sequence of speech-mode BFIs to put the ECU in
state 6, then SID and CN-mode BFIs, then a good speech frame) that
would be broken by that buffer reuse approach. We could eliminate
this corner case by resetting the ECU state when passing through
a CN insertion period, but doing so would needlessly increase
the behavioral diffs between GSM 06.06 and our version.
Solution: use a separate CN-specific buffer for CN R0+LPC parameters,
and match the behavior of GSM 06.06 code in this regard.
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Thu, 13 Feb 2025 10:02:45 +0000 |
parents | 72cf52ba91f8 |
children |
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/************************************************************************* * FUNCTION: Q_plsf_5() * * PURPOSE: Quantization of 2 sets of LSF parameters using 1st order MA * prediction and split by 5 matrix quantization (split-MQ) * * DESCRIPTION: * * p[i] = pred_factor*past_r2q[i]; i=0,...,m-1 * r1[i]= lsf1[i] - p[i]; i=0,...,m-1 * r2[i]= lsf2[i] - p[i]; i=0,...,m-1 * where: * lsf1[i] 1st mean-removed LSF vector. * lsf2[i] 2nd mean-removed LSF vector. * r1[i] 1st residual prediction vector. * r2[i] 2nd residual prediction vector. * past_r2q[i] Past quantized residual (2nd vector). * * The residual vectors r1[i] and r2[i] are jointly quantized using * split-MQ with 5 codebooks. Each 4th dimension submatrix contains 2 * elements from each residual vector. The 5 submatrices are as follows: * {r1[0], r1[1], r2[0], r2[1]}; {r1[2], r1[3], r2[2], r2[3]}; * {r1[4], r1[5], r2[4], r2[5]}; {r1[6], r1[7], r2[6], r2[7]}; * {r1[8], r1[9], r2[8], r2[9]}; * *************************************************************************/ #include "gsm_efr.h" #include "typedef.h" #include "namespace.h" #include "basic_op.h" #include "no_count.h" #include "sig_proc.h" #include "codec.h" #include "cnst.h" #include "dtx.h" #include "enc_state.h" #include "q_plsf5_tab.h" /* Codebooks of LSF prediction residual */ /* Locals functions */ static void Lsf_wt ( Word16 *lsf, /* input : LSF vector */ Word16 *wf2 /* output: square of weighting factors */ ); static Word16 Vq_subvec ( /* output: return quantization index */ Word16 *lsf_r1, /* input : 1st LSF residual vector */ Word16 *lsf_r2, /* input : and LSF residual vector */ const Word16 *dico,/* input : quantization codebook */ Word16 *wf1, /* input : 1st LSF weighting factors */ Word16 *wf2, /* input : 2nd LSF weighting factors */ Word16 dico_size /* input : size of quantization codebook */ ); static Word16 Vq_subvec_s ( /* output: return quantization index */ Word16 *lsf_r1, /* input : 1st LSF residual vector */ Word16 *lsf_r2, /* input : and LSF residual vector */ const Word16 *dico,/* input : quantization codebook */ Word16 *wf1, /* input : 1st LSF weighting factors */ Word16 *wf2, /* input : 2nd LSF weighting factors */ Word16 dico_size /* input : size of quantization codebook */ ); /* M ->order of linear prediction filter */ /* LSF_GAP -> Minimum distance between LSF after quantization */ /* 50 Hz = 205 */ /* PRED_FAC -> Predcition factor */ #define M 10 #define LSF_GAP 205 #define PRED_FAC 21299 void Q_plsf_5 ( struct EFR_encoder_state *st, Word16 *lsp1, /* input : 1st LSP vector */ Word16 *lsp2, /* input : 2nd LSP vector */ Word16 *lsp1_q, /* output: quantized 1st LSP vector */ Word16 *lsp2_q, /* output: quantized 2nd LSP vector */ Word16 *indice, /* output: quantization indices of 5 matrices */ Word16 txdtx_ctrl /* input : tx dtx control word */ ) { Word16 i; Word16 lsf1[M], lsf2[M], wf1[M], wf2[M], lsf_p[M], lsf_r1[M], lsf_r2[M]; Word16 lsf1_q[M], lsf2_q[M]; Word16 lsf_aver[M]; /* convert LSFs to normalize frequency domain 0..16384 */ Lsp_lsf (lsp1, lsf1, M); Lsp_lsf (lsp2, lsf2, M); /* Update LSF CN quantizer "memory" */ if ((txdtx_ctrl & TX_SP_FLAG) == 0 && (txdtx_ctrl & TX_PREV_HANGOVER_ACTIVE) != 0) { update_lsf_p_CN (st->lsf_old_tx, st->lsf_p_CN); } if ((txdtx_ctrl & TX_SID_UPDATE) != 0) { /* New SID frame is to be sent: Compute average of the current LSFs and the LSFs in the history */ aver_lsf_history (st->lsf_old_tx, lsf1, lsf2, lsf_aver); } /* Update LSF history with unquantized LSFs when no speech activity is present */ if ((txdtx_ctrl & TX_SP_FLAG) == 0) { update_lsf_history (lsf1, lsf2, st->lsf_old_tx); } if ((txdtx_ctrl & TX_SID_UPDATE) != 0) { /* Compute LSF weighting factors for lsf2, using averaged LSFs */ /* Set LSF weighting factors for lsf1 to zero */ /* Replace lsf1 and lsf2 by the averaged LSFs */ Lsf_wt (lsf_aver, wf2); for (i = 0; i < M; i++) { wf1[i] = 0; move16 (); lsf1[i] = lsf_aver[i]; move16 (); lsf2[i] = lsf_aver[i]; move16 (); } } else { /* Compute LSF weighting factors */ Lsf_wt (lsf1, wf1); Lsf_wt (lsf2, wf2); } /* Compute predicted LSF and prediction error */ if ((txdtx_ctrl & TX_SP_FLAG) != 0) { for (i = 0; i < M; i++) { lsf_p[i] = add (mean_lsf[i], mult (st->past_r2_q[i], PRED_FAC)); lsf_r1[i] = sub (lsf1[i], lsf_p[i]); lsf_r2[i] = sub (lsf2[i], lsf_p[i]); } } else { for (i = 0; i < M; i++) { lsf_r1[i] = sub (lsf1[i], st->lsf_p_CN[i]); lsf_r2[i] = sub (lsf2[i], st->lsf_p_CN[i]); } } /*---- Split-VQ of prediction error ----*/ indice[0] = Vq_subvec (&lsf_r1[0], &lsf_r2[0], dico1_lsf, &wf1[0], &wf2[0], DICO1_SIZE); move16 (); indice[1] = Vq_subvec (&lsf_r1[2], &lsf_r2[2], dico2_lsf, &wf1[2], &wf2[2], DICO2_SIZE); move16 (); indice[2] = Vq_subvec_s (&lsf_r1[4], &lsf_r2[4], dico3_lsf, &wf1[4], &wf2[4], DICO3_SIZE); move16 (); indice[3] = Vq_subvec (&lsf_r1[6], &lsf_r2[6], dico4_lsf, &wf1[6], &wf2[6], DICO4_SIZE); move16 (); indice[4] = Vq_subvec (&lsf_r1[8], &lsf_r2[8], dico5_lsf, &wf1[8], &wf2[8], DICO5_SIZE); move16 (); /* Compute quantized LSFs and update the past quantized residual */ /* In case of no speech activity, skip computing the quantized LSFs, and set past_r2_q to zero (initial value) */ if ((txdtx_ctrl & TX_SP_FLAG) != 0) { for (i = 0; i < M; i++) { lsf1_q[i] = add (lsf_r1[i], lsf_p[i]); lsf2_q[i] = add (lsf_r2[i], lsf_p[i]); st->past_r2_q[i] = lsf_r2[i]; } /* verification that LSFs has minimum distance of LSF_GAP */ Reorder_lsf (lsf1_q, LSF_GAP, M); Reorder_lsf (lsf2_q, LSF_GAP, M); /* Update LSF history with quantized LSFs when hangover period is active */ if ((txdtx_ctrl & TX_HANGOVER_ACTIVE) != 0) { update_lsf_history (lsf1_q, lsf2_q, st->lsf_old_tx); } /* convert LSFs to the cosine domain */ Lsf_lsp (lsf1_q, lsp1_q, M); Lsf_lsp (lsf2_q, lsp2_q, M); } else { for (i = 0; i < M; i++) { st->past_r2_q[i] = 0; } } return; } /* Quantization of a 4 dimensional subvector */ static Word16 Vq_subvec ( /* output: return quantization index */ Word16 *lsf_r1, /* input : 1st LSF residual vector */ Word16 *lsf_r2, /* input : and LSF residual vector */ const Word16 *dico, /* input : quantization codebook */ Word16 *wf1, /* input : 1st LSF weighting factors */ Word16 *wf2, /* input : 2nd LSF weighting factors */ Word16 dico_size /* input : size of quantization codebook */ ) { Word16 i, index, temp; const Word16 *p_dico; Word32 dist_min, dist; dist_min = MAX_32; move32 (); p_dico = dico; move16 (); for (i = 0; i < dico_size; i++) { temp = sub (lsf_r1[0], *p_dico++); temp = mult (wf1[0], temp); dist = L_mult (temp, temp); temp = sub (lsf_r1[1], *p_dico++); temp = mult (wf1[1], temp); dist = L_mac (dist, temp, temp); temp = sub (lsf_r2[0], *p_dico++); temp = mult (wf2[0], temp); dist = L_mac (dist, temp, temp); temp = sub (lsf_r2[1], *p_dico++); temp = mult (wf2[1], temp); dist = L_mac (dist, temp, temp); test (); if (dist < dist_min) { dist_min = dist; move32 (); index = i; move16 (); } } /* Reading the selected vector */ p_dico = &dico[shl (index, 2)]; move16 (); lsf_r1[0] = *p_dico++; move16 (); lsf_r1[1] = *p_dico++; move16 (); lsf_r2[0] = *p_dico++; move16 (); lsf_r2[1] = *p_dico++; move16 (); return index; } /* Quantization of a 4 dimensional subvector with a signed codebook */ static Word16 Vq_subvec_s ( /* output: return quantization index */ Word16 *lsf_r1, /* input : 1st LSF residual vector */ Word16 *lsf_r2, /* input : and LSF residual vector */ const Word16 *dico, /* input : quantization codebook */ Word16 *wf1, /* input : 1st LSF weighting factors */ Word16 *wf2, /* input : 2nd LSF weighting factors */ Word16 dico_size) /* input : size of quantization codebook */ { Word16 i, index, sign, temp; const Word16 *p_dico; Word32 dist_min, dist; dist_min = MAX_32; move32 (); p_dico = dico; move16 (); for (i = 0; i < dico_size; i++) { /* test positive */ temp = sub (lsf_r1[0], *p_dico++); temp = mult (wf1[0], temp); dist = L_mult (temp, temp); temp = sub (lsf_r1[1], *p_dico++); temp = mult (wf1[1], temp); dist = L_mac (dist, temp, temp); temp = sub (lsf_r2[0], *p_dico++); temp = mult (wf2[0], temp); dist = L_mac (dist, temp, temp); temp = sub (lsf_r2[1], *p_dico++); temp = mult (wf2[1], temp); dist = L_mac (dist, temp, temp); test (); if (dist < dist_min) { dist_min = dist; move32 (); index = i; move16 (); sign = 0; move16 (); } /* test negative */ p_dico -= 4; move16 (); temp = add (lsf_r1[0], *p_dico++); temp = mult (wf1[0], temp); dist = L_mult (temp, temp); temp = add (lsf_r1[1], *p_dico++); temp = mult (wf1[1], temp); dist = L_mac (dist, temp, temp); temp = add (lsf_r2[0], *p_dico++); temp = mult (wf2[0], temp); dist = L_mac (dist, temp, temp); temp = add (lsf_r2[1], *p_dico++); temp = mult (wf2[1], temp); dist = L_mac (dist, temp, temp); test (); if (dist < dist_min) { dist_min = dist; move32 (); index = i; move16 (); sign = 1; move16 (); } } /* Reading the selected vector */ p_dico = &dico[shl (index, 2)]; move16 (); test (); if (sign == 0) { lsf_r1[0] = *p_dico++; move16 (); lsf_r1[1] = *p_dico++; move16 (); lsf_r2[0] = *p_dico++; move16 (); lsf_r2[1] = *p_dico++; move16 (); } else { lsf_r1[0] = negate (*p_dico++); move16 (); lsf_r1[1] = negate (*p_dico++); move16 (); lsf_r2[0] = negate (*p_dico++); move16 (); lsf_r2[1] = negate (*p_dico++); move16 (); } index = shl (index, 1); index = add (index, sign); return index; } /**************************************************** * FUNCTION Lsf_wt * * * **************************************************** * Compute LSF weighting factors * * * * d[i] = lsf[i+1] - lsf[i-1] * * * * The weighting factors are approximated by two line segment. * * * * First segment passes by the following 2 points: * * * * d[i] = 0Hz wf[i] = 3.347 * * d[i] = 450Hz wf[i] = 1.8 * * * * Second segment passes by the following 2 points: * * * * d[i] = 450Hz wf[i] = 1.8 * * d[i] = 1500Hz wf[i] = 1.0 * * * * if( d[i] < 450Hz ) * * wf[i] = 3.347 - ( (3.347-1.8) / (450-0)) * d[i] * * else * * wf[i] = 1.8 - ( (1.8-1.0) / (1500-450)) * (d[i] - 450) * * * * * * if( d[i] < 1843) * * wf[i] = 3427 - (28160*d[i])>>15 * * else * * wf[i] = 1843 - (6242*(d[i]-1843))>>15 * * * *--------------------------------------------------------------------------*/ static void Lsf_wt ( Word16 *lsf, /* input : LSF vector */ Word16 *wf) /* output: square of weighting factors */ { Word16 temp; Word16 i; /* wf[0] = lsf[1] - 0 */ wf[0] = lsf[1]; move16 (); for (i = 1; i < 9; i++) { wf[i] = sub (lsf[i + 1], lsf[i - 1]); move16 (); } /* wf[9] = 0.5 - lsf[8] */ wf[9] = sub (16384, lsf[8]);move16 (); for (i = 0; i < 10; i++) { temp = sub (wf[i], 1843); test (); if (temp < 0) { wf[i] = sub (3427, mult (wf[i], 28160)); move16 (); } else { wf[i] = sub (1843, mult (temp, 6242)); move16 (); } wf[i] = shl (wf[i], 3); move16 (); } return; }