FreeCalypso > hg > gsm-codec-lib
view libgsmfr2/short_term.c @ 282:9ee8ad3d4d30
frtest: rm gsmfr-hand-test and gsmfr-max-out utils
These hack programs were never properly documented and were written
only as part of a debug chase, in pursuit of a bug that ultimately
turned out to be in our then-hacky patch to osmo-bts-sysmo,
before beginning of proper patches in Osmocom. These hack programs
need to be dropped from the present sw package because they depend
on old libgsm, and we are eliminating that dependency.
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Sun, 14 Apr 2024 05:44:47 +0000 |
parents | d320a8fa3392 |
children |
line wrap: on
line source
/* * 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); }