FreeCalypso > hg > gsm-codec-lib
view libgsmfr2/short_term.c @ 449:2af2b5c12268
Library-versions: libtwamr is officially version 1.0.0
author | Mychaela Falconia <falcon@freecalypso.org> |
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date | Fri, 10 May 2024 01:43:05 +0000 |
parents | d320a8fa3392 |
children |
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/* * This C source file has been adapted from TU-Berlin libgsm source, * original notice follows: * * Copyright 1992 by Jutta Degener and Carsten Bormann, Technische * Universitaet Berlin. See the accompanying file "COPYRIGHT" for * details. THERE IS ABSOLUTELY NO WARRANTY FOR THIS SOFTWARE. */ #include <stdint.h> #include "tw_gsmfr.h" #include "typedef.h" #include "ed_state.h" #include "ed_internal.h" /* * SHORT TERM ANALYSIS FILTERING SECTION */ /* 4.2.8 */ static void Decoding_of_the_coded_Log_Area_Ratios ( const word * LARc, /* coded log area ratio [0..7] IN */ word * LARpp) /* out: decoded .. */ { register word temp1 /* , temp2 */; register long ltmp; /* for GSM_ADD */ /* This procedure requires for efficient implementation * two tables. * * INVA[1..8] = integer( (32768 * 8) / real_A[1..8]) * MIC[1..8] = minimum value of the LARc[1..8] */ /* Compute the LARpp[1..8] */ /* for (i = 1; i <= 8; i++, B++, MIC++, INVA++, LARc++, LARpp++) { * * temp1 = GSM_ADD( *LARc, *MIC ) << 10; * temp2 = *B << 1; * temp1 = GSM_SUB( temp1, temp2 ); * * assert(*INVA != MIN_WORD); * * temp1 = GSM_MULT_R( *INVA, temp1 ); * *LARpp = GSM_ADD( temp1, temp1 ); * } */ #undef STEP #define STEP( B_TIMES_TWO, MIC, INVA ) \ temp1 = GSM_ADD( *LARc++, MIC ) << 10; \ temp1 = GSM_SUB( temp1, B_TIMES_TWO ); \ temp1 = GSM_MULT_R( INVA, temp1 ); \ *LARpp++ = GSM_ADD( temp1, temp1 ); STEP( 0, -32, 13107 ); STEP( 0, -32, 13107 ); STEP( 4096, -16, 13107 ); STEP( -5120, -16, 13107 ); STEP( 188, -8, 19223 ); STEP( -3584, -8, 17476 ); STEP( -682, -4, 31454 ); STEP( -2288, -4, 29708 ); /* NOTE: the addition of *MIC is used to restore * the sign of *LARc. */ } /* 4.2.9 */ /* Computation of the quantized reflection coefficients */ /* 4.2.9.1 Interpolation of the LARpp[1..8] to get the LARp[1..8] */ /* * Within each frame of 160 analyzed speech samples the short term * analysis and synthesis filters operate with four different sets of * coefficients, derived from the previous set of decoded LARs(LARpp(j-1)) * and the actual set of decoded LARs (LARpp(j)) * * (Initial value: LARpp(j-1)[1..8] = 0.) */ static void Coefficients_0_12 ( register word * LARpp_j_1, register word * LARpp_j, register word * LARp) { register int i; register longword ltmp; for (i = 1; i <= 8; i++, LARp++, LARpp_j_1++, LARpp_j++) { *LARp = GSM_ADD( SASR( *LARpp_j_1, 2 ), SASR( *LARpp_j, 2 )); *LARp = GSM_ADD( *LARp, SASR( *LARpp_j_1, 1)); } } static void Coefficients_13_26 ( register word * LARpp_j_1, register word * LARpp_j, register word * LARp) { register int i; register longword ltmp; for (i = 1; i <= 8; i++, LARpp_j_1++, LARpp_j++, LARp++) { *LARp = GSM_ADD( SASR( *LARpp_j_1, 1), SASR( *LARpp_j, 1 )); } } static void Coefficients_27_39 ( register word * LARpp_j_1, register word * LARpp_j, register word * LARp) { register int i; register longword ltmp; for (i = 1; i <= 8; i++, LARpp_j_1++, LARpp_j++, LARp++) { *LARp = GSM_ADD( SASR( *LARpp_j_1, 2 ), SASR( *LARpp_j, 2 )); *LARp = GSM_ADD( *LARp, SASR( *LARpp_j, 1 )); } } static void Coefficients_40_159 ( register word * LARpp_j, register word * LARp) { register int i; for (i = 1; i <= 8; i++, LARp++, LARpp_j++) *LARp = *LARpp_j; } /* 4.2.9.2 */ static void LARp_to_rp ( register word * LARp) /* [0..7] IN/OUT */ /* * The input of this procedure is the interpolated LARp[0..7] array. * The reflection coefficients, rp[i], are used in the analysis * filter and in the synthesis filter. */ { register int i; register word temp; register longword ltmp; for (i = 1; i <= 8; i++, LARp++) { /* temp = GSM_ABS( *LARp ); * * if (temp < 11059) temp <<= 1; * else if (temp < 20070) temp += 11059; * else temp = GSM_ADD( temp >> 2, 26112 ); * * *LARp = *LARp < 0 ? -temp : temp; */ if (*LARp < 0) { temp = *LARp == MIN_WORD ? MAX_WORD : -(*LARp); *LARp = - ((temp < 11059) ? temp << 1 : ((temp < 20070) ? temp + 11059 : GSM_ADD( temp >> 2, 26112 ))); } else { temp = *LARp; *LARp = (temp < 11059) ? temp << 1 : ((temp < 20070) ? temp + 11059 : GSM_ADD( temp >> 2, 26112 )); } } } /* 4.2.10 */ static void Short_term_analysis_filtering ( struct gsmfr_0610_state * S, register word * rp, /* [0..7] IN */ register int k_n, /* k_end - k_start */ register word * s /* [0..n-1] IN/OUT */ ) /* * This procedure computes the short term residual signal d[..] to be fed * to the RPE-LTP loop from the s[..] signal and from the local rp[..] * array (quantized reflection coefficients). As the call of this * procedure can be done in many ways (see the interpolation of the LAR * coefficient), it is assumed that the computation begins with index * k_start (for arrays d[..] and s[..]) and stops with index k_end * (k_start and k_end are defined in 4.2.9.1). This procedure also * needs to keep the array u[0..7] in memory for each call. */ { register word * u = S->u; register int i; register word di, zzz, ui, sav, rpi; register longword ltmp; for (; k_n--; s++) { di = sav = *s; for (i = 0; i < 8; i++) { /* YYY */ ui = u[i]; rpi = rp[i]; u[i] = sav; zzz = GSM_MULT_R(rpi, di); sav = GSM_ADD( ui, zzz); zzz = GSM_MULT_R(rpi, ui); di = GSM_ADD( di, zzz ); } *s = di; } } static void Short_term_synthesis_filtering ( struct gsmfr_0610_state * S, register word * rrp, /* [0..7] IN */ register int k, /* k_end - k_start */ register word * wt, /* [0..k-1] IN */ register word * sr /* [0..k-1] OUT */ ) { register word * v = S->v; register int i; register word sri, tmp1, tmp2; register longword ltmp; /* for GSM_ADD & GSM_SUB */ while (k--) { sri = *wt++; for (i = 8; i--;) { /* sri = GSM_SUB( sri, gsm_mult_r( rrp[i], v[i] ) ); */ tmp1 = rrp[i]; tmp2 = v[i]; tmp2 = ( tmp1 == MIN_WORD && tmp2 == MIN_WORD ? MAX_WORD : 0x0FFFF & (( (longword)tmp1 * (longword)tmp2 + 16384) >> 15)) ; sri = GSM_SUB( sri, tmp2 ); /* v[i+1] = GSM_ADD( v[i], gsm_mult_r( rrp[i], sri ) ); */ tmp1 = ( tmp1 == MIN_WORD && sri == MIN_WORD ? MAX_WORD : 0x0FFFF & (( (longword)tmp1 * (longword)sri + 16384) >> 15)) ; v[i+1] = GSM_ADD( v[i], tmp1); } *sr++ = v[0] = sri; } } void Gsm_Short_Term_Analysis_Filter ( struct gsmfr_0610_state * S, const word * LARc, /* coded log area ratio [0..7] IN */ word * s /* signal [0..159] IN/OUT */ ) { word * LARpp_j = S->LARpp[ S->j ]; word * LARpp_j_1 = S->LARpp[ S->j ^= 1 ]; word LARp[8]; #undef FILTER # define FILTER Short_term_analysis_filtering Decoding_of_the_coded_Log_Area_Ratios( LARc, LARpp_j ); Coefficients_0_12( LARpp_j_1, LARpp_j, LARp ); LARp_to_rp( LARp ); FILTER( S, LARp, 13, s); Coefficients_13_26( LARpp_j_1, LARpp_j, LARp); LARp_to_rp( LARp ); FILTER( S, LARp, 14, s + 13); Coefficients_27_39( LARpp_j_1, LARpp_j, LARp); LARp_to_rp( LARp ); FILTER( S, LARp, 13, s + 27); Coefficients_40_159( LARpp_j, LARp); LARp_to_rp( LARp ); FILTER( S, LARp, 120, s + 40); } void Gsm_Short_Term_Synthesis_Filter ( struct gsmfr_0610_state * S, const word * LARcr, /* received log area ratios [0..7] IN */ word * wt, /* received d [0..159] IN */ word * s /* signal s [0..159] OUT */ ) { word * LARpp_j = S->LARpp[ S->j ]; word * LARpp_j_1 = S->LARpp[ S->j ^=1 ]; word LARp[8]; #undef FILTER # define FILTER Short_term_synthesis_filtering Decoding_of_the_coded_Log_Area_Ratios( LARcr, LARpp_j ); Coefficients_0_12( LARpp_j_1, LARpp_j, LARp ); LARp_to_rp( LARp ); FILTER( S, LARp, 13, wt, s ); Coefficients_13_26( LARpp_j_1, LARpp_j, LARp); LARp_to_rp( LARp ); FILTER( S, LARp, 14, wt + 13, s + 13 ); Coefficients_27_39( LARpp_j_1, LARpp_j, LARp); LARp_to_rp( LARp ); FILTER( S, LARp, 13, wt + 27, s + 27 ); Coefficients_40_159( LARpp_j, LARp ); LARp_to_rp( LARp ); FILTER(S, LARp, 120, wt + 40, s + 40); }