FreeCalypso > hg > gsm-codec-lib
view libtwamr/cl_ltp.c @ 452:6e595f7d40e2
CHANGES: document changes for the upcoming release
author | Mychaela Falconia <falcon@freecalypso.org> |
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date | Fri, 10 May 2024 03:45:47 +0000 |
parents | 85e9768d497f |
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 : cl_ltp.c * ***************************************************************************** */ /* ***************************************************************************** * MODULE INCLUDE FILE AND VERSION ID ***************************************************************************** */ #include "namespace.h" #include "cl_ltp.h" /* ***************************************************************************** * INCLUDE FILES ***************************************************************************** */ #include <stddef.h> #include "typedef.h" #include "basic_op.h" #include "no_count.h" #include "oper_32b.h" #include "cnst.h" #include "convolve.h" #include "g_pitch.h" #include "pred_lt.h" #include "pitch_fr.h" #include "enc_lag3.h" #include "enc_lag6.h" #include "q_gain_p.h" #include "ton_stab.h" /* ***************************************************************************** * LOCAL VARIABLES AND TABLES ***************************************************************************** */ /* ***************************************************************************** * PUBLIC PROGRAM CODE ***************************************************************************** */ /************************************************************************* * * Function: cl_ltp_reset * Purpose: Initializes state memory to zero * ************************************************************************** */ void cl_ltp_reset (clLtpState *state) { /* Reset pitch search states */ Pitch_fr_reset (&state->pitchSt); } /************************************************************************* * * Function: cl_ltp * Purpose: closed-loop fractional pitch search * ************************************************************************** */ int cl_ltp ( clLtpState *clSt, /* i/o : State struct */ tonStabState *tonSt, /* i/o : State struct */ enum Mode mode, /* i : coder mode */ Word16 frameOffset, /* i : Offset to subframe */ Word16 T_op[], /* i : Open loop pitch lags */ Word16 *h1, /* i : Impulse response vector Q12 */ Word16 *exc, /* i/o : Excitation vector Q0 */ Word16 res2[], /* i/o : Long term prediction residual Q0 */ Word16 xn[], /* i : Target vector for pitch search Q0 */ Word16 lsp_flag, /* i : LSP resonance flag */ Word16 xn2[], /* o : Target vector for codebook search Q0 */ Word16 y1[], /* o : Filtered adaptive excitation Q0 */ Word16 *T0, /* o : Pitch delay (integer part) */ Word16 *T0_frac, /* o : Pitch delay (fractional part) */ Word16 *gain_pit, /* o : Pitch gain Q14 */ Word16 g_coeff[], /* o : Correlations between xn, y1, & y2 */ Word16 **anap, /* o : Analysis parameters */ Word16 *gp_limit /* o : pitch gain limit */ ) { Word16 i; Word16 index; Word32 L_temp; /* temporarily variable */ Word16 resu3; /* flag for upsample resolution */ Word16 gpc_flag; /*----------------------------------------------------------------------* * Closed-loop fractional pitch search * *----------------------------------------------------------------------*/ *T0 = Pitch_fr(&clSt->pitchSt, mode, T_op, exc, xn, h1, L_SUBFR, frameOffset, T0_frac, &resu3, &index); move16 (); *(*anap)++ = index; move16 (); /*-----------------------------------------------------------------* * - find unity gain pitch excitation (adapitve codebook entry) * * with fractional interpolation. * * - find filtered pitch exc. y1[]=exc[] convolve with h1[]) * * - compute pitch gain and limit between 0 and 1.2 * * - update target vector for codebook search * * - find LTP residual. * *-----------------------------------------------------------------*/ Pred_lt_3or6(exc, *T0, *T0_frac, L_SUBFR, resu3); Convolve(exc, h1, y1, L_SUBFR); /* gain_pit is Q14 for all modes */ *gain_pit = G_pitch(mode, xn, y1, g_coeff, L_SUBFR); move16 (); /* check if the pitch gain should be limit due to resonance in LPC filter */ gpc_flag = 0; move16 (); *gp_limit = MAX_16; move16 (); test (); test (); if ((lsp_flag != 0) && (sub(*gain_pit, GP_CLIP) > 0)) { gpc_flag = check_gp_clipping(tonSt, *gain_pit); move16 (); } /* special for the MR475, MR515 mode; limit the gain to 0.85 to */ /* cope with bit errors in the decoder in a better way. */ test (); test (); if ((sub (mode, MR475) == 0) || (sub (mode, MR515) == 0)) { test (); if ( sub (*gain_pit, 13926) > 0) { *gain_pit = 13926; /* 0.85 in Q14 */ move16 (); } test (); if (gpc_flag != 0) { *gp_limit = GP_CLIP; move16 (); } } else { test (); if (gpc_flag != 0) { *gp_limit = GP_CLIP; move16 (); *gain_pit = GP_CLIP; move16 (); } /* For MR122, gain_pit is quantized here and not in gainQuant */ if (test (), sub(mode, MR122)==0) { *(*anap)++ = q_gain_pitch(MR122, *gp_limit, gain_pit, NULL, NULL); move16 (); } } /* update target vector und evaluate LTP residual */ for (i = 0; i < L_SUBFR; i++) { L_temp = L_mult(y1[i], *gain_pit); L_temp = L_shl(L_temp, 1); xn2[i] = sub(xn[i], extract_h(L_temp)); move16 (); L_temp = L_mult(exc[i], *gain_pit); L_temp = L_shl(L_temp, 1); res2[i] = sub(res2[i], extract_h(L_temp)); move16 (); } return 0; }