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Diffstat (limited to 'gr-gsm-fr-vocoder/src/lib/gsm/long_term.c')
| -rw-r--r-- | gr-gsm-fr-vocoder/src/lib/gsm/long_term.c | 949 |
1 files changed, 949 insertions, 0 deletions
diff --git a/gr-gsm-fr-vocoder/src/lib/gsm/long_term.c b/gr-gsm-fr-vocoder/src/lib/gsm/long_term.c new file mode 100644 index 000000000..fd67bda19 --- /dev/null +++ b/gr-gsm-fr-vocoder/src/lib/gsm/long_term.c @@ -0,0 +1,949 @@ +/* + * 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. + */ + +/* $Header$ */ + +#include <stdio.h> +#include <assert.h> + +#include "private.h" + +#include "gsm.h" +#include "proto.h" + +/* + * 4.2.11 .. 4.2.12 LONG TERM PREDICTOR (LTP) SECTION + */ + + +/* + * This module computes the LTP gain (bc) and the LTP lag (Nc) + * for the long term analysis filter. This is done by calculating a + * maximum of the cross-correlation function between the current + * sub-segment short term residual signal d[0..39] (output of + * the short term analysis filter; for simplification the index + * of this array begins at 0 and ends at 39 for each sub-segment of the + * RPE-LTP analysis) and the previous reconstructed short term + * residual signal dp[ -120 .. -1 ]. A dynamic scaling must be + * performed to avoid overflow. + */ + + /* The next procedure exists in six versions. First two integer + * version (if USE_FLOAT_MUL is not defined); then four floating + * point versions, twice with proper scaling (USE_FLOAT_MUL defined), + * once without (USE_FLOAT_MUL and FAST defined, and fast run-time + * option used). Every pair has first a Cut version (see the -C + * option to toast or the LTP_CUT option to gsm_option()), then the + * uncut one. (For a detailed explanation of why this is altogether + * a bad idea, see Henry Spencer and Geoff Collyer, ``#ifdef Considered + * Harmful''.) + */ + +#ifndef USE_FLOAT_MUL + +#ifdef LTP_CUT + +static void Cut_Calculation_of_the_LTP_parameters P5((st, d,dp,bc_out,Nc_out), + + struct gsm_state * st, + + register word * d, /* [0..39] IN */ + register word * dp, /* [-120..-1] IN */ + word * bc_out, /* OUT */ + word * Nc_out /* OUT */ +) +{ + register int k, lambda; + word Nc, bc; + word wt[40]; + + longword L_result; + longword L_max, L_power; + word R, S, dmax, scal, best_k; + word ltp_cut; + + register word temp, wt_k; + + /* Search of the optimum scaling of d[0..39]. + */ + dmax = 0; + for (k = 0; k <= 39; k++) { + temp = d[k]; + temp = GSM_ABS( temp ); + if (temp > dmax) { + dmax = temp; + best_k = k; + } + } + temp = 0; + if (dmax == 0) scal = 0; + else { + assert(dmax > 0); + temp = gsm_norm( (longword)dmax << 16 ); + } + if (temp > 6) scal = 0; + else scal = 6 - temp; + assert(scal >= 0); + + /* Search for the maximum cross-correlation and coding of the LTP lag + */ + L_max = 0; + Nc = 40; /* index for the maximum cross-correlation */ + wt_k = SASR(d[best_k], scal); + + for (lambda = 40; lambda <= 120; lambda++) { + L_result = (longword)wt_k * dp[best_k - lambda]; + if (L_result > L_max) { + Nc = lambda; + L_max = L_result; + } + } + *Nc_out = Nc; + L_max <<= 1; + + /* Rescaling of L_max + */ + assert(scal <= 100 && scal >= -100); + L_max = L_max >> (6 - scal); /* sub(6, scal) */ + + assert( Nc <= 120 && Nc >= 40); + + /* Compute the power of the reconstructed short term residual + * signal dp[..] + */ + L_power = 0; + for (k = 0; k <= 39; k++) { + + register longword L_temp; + + L_temp = SASR( dp[k - Nc], 3 ); + L_power += L_temp * L_temp; + } + L_power <<= 1; /* from L_MULT */ + + /* Normalization of L_max and L_power + */ + + if (L_max <= 0) { + *bc_out = 0; + return; + } + if (L_max >= L_power) { + *bc_out = 3; + return; + } + + temp = gsm_norm( L_power ); + + R = SASR( L_max << temp, 16 ); + S = SASR( L_power << temp, 16 ); + + /* Coding of the LTP gain + */ + + /* Table 4.3a must be used to obtain the level DLB[i] for the + * quantization of the LTP gain b to get the coded version bc. + */ + for (bc = 0; bc <= 2; bc++) if (R <= gsm_mult(S, gsm_DLB[bc])) break; + *bc_out = bc; +} + +#endif /* LTP_CUT */ + +static void Calculation_of_the_LTP_parameters P4((d,dp,bc_out,Nc_out), + register word * d, /* [0..39] IN */ + register word * dp, /* [-120..-1] IN */ + word * bc_out, /* OUT */ + word * Nc_out /* OUT */ +) +{ + register int k, lambda; + word Nc, bc; + word wt[40]; + + longword L_max, L_power; + word R, S, dmax, scal; + register word temp; + + /* Search of the optimum scaling of d[0..39]. + */ + dmax = 0; + + for (k = 0; k <= 39; k++) { + temp = d[k]; + temp = GSM_ABS( temp ); + if (temp > dmax) dmax = temp; + } + + temp = 0; + if (dmax == 0) scal = 0; + else { + assert(dmax > 0); + temp = gsm_norm( (longword)dmax << 16 ); + } + + if (temp > 6) scal = 0; + else scal = 6 - temp; + + assert(scal >= 0); + + /* Initialization of a working array wt + */ + + for (k = 0; k <= 39; k++) wt[k] = SASR( d[k], scal ); + + /* Search for the maximum cross-correlation and coding of the LTP lag + */ + L_max = 0; + Nc = 40; /* index for the maximum cross-correlation */ + + for (lambda = 40; lambda <= 120; lambda++) { + +# undef STEP +# define STEP(k) (longword)wt[k] * dp[k - lambda] + + register longword L_result; + + L_result = STEP(0) ; L_result += STEP(1) ; + L_result += STEP(2) ; L_result += STEP(3) ; + L_result += STEP(4) ; L_result += STEP(5) ; + L_result += STEP(6) ; L_result += STEP(7) ; + L_result += STEP(8) ; L_result += STEP(9) ; + L_result += STEP(10) ; L_result += STEP(11) ; + L_result += STEP(12) ; L_result += STEP(13) ; + L_result += STEP(14) ; L_result += STEP(15) ; + L_result += STEP(16) ; L_result += STEP(17) ; + L_result += STEP(18) ; L_result += STEP(19) ; + L_result += STEP(20) ; L_result += STEP(21) ; + L_result += STEP(22) ; L_result += STEP(23) ; + L_result += STEP(24) ; L_result += STEP(25) ; + L_result += STEP(26) ; L_result += STEP(27) ; + L_result += STEP(28) ; L_result += STEP(29) ; + L_result += STEP(30) ; L_result += STEP(31) ; + L_result += STEP(32) ; L_result += STEP(33) ; + L_result += STEP(34) ; L_result += STEP(35) ; + L_result += STEP(36) ; L_result += STEP(37) ; + L_result += STEP(38) ; L_result += STEP(39) ; + + if (L_result > L_max) { + + Nc = lambda; + L_max = L_result; + } + } + + *Nc_out = Nc; + + L_max <<= 1; + + /* Rescaling of L_max + */ + assert(scal <= 100 && scal >= -100); + L_max = L_max >> (6 - scal); /* sub(6, scal) */ + + assert( Nc <= 120 && Nc >= 40); + + /* Compute the power of the reconstructed short term residual + * signal dp[..] + */ + L_power = 0; + for (k = 0; k <= 39; k++) { + + register longword L_temp; + + L_temp = SASR( dp[k - Nc], 3 ); + L_power += L_temp * L_temp; + } + L_power <<= 1; /* from L_MULT */ + + /* Normalization of L_max and L_power + */ + + if (L_max <= 0) { + *bc_out = 0; + return; + } + if (L_max >= L_power) { + *bc_out = 3; + return; + } + + temp = gsm_norm( L_power ); + + R = SASR( L_max << temp, 16 ); + S = SASR( L_power << temp, 16 ); + + /* Coding of the LTP gain + */ + + /* Table 4.3a must be used to obtain the level DLB[i] for the + * quantization of the LTP gain b to get the coded version bc. + */ + for (bc = 0; bc <= 2; bc++) if (R <= gsm_mult(S, gsm_DLB[bc])) break; + *bc_out = bc; +} + +#else /* USE_FLOAT_MUL */ + +#ifdef LTP_CUT + +static void Cut_Calculation_of_the_LTP_parameters P5((st, d,dp,bc_out,Nc_out), + struct gsm_state * st, /* IN */ + register word * d, /* [0..39] IN */ + register word * dp, /* [-120..-1] IN */ + word * bc_out, /* OUT */ + word * Nc_out /* OUT */ +) +{ + register int k, lambda; + word Nc, bc; + word ltp_cut; + + float wt_float[40]; + float dp_float_base[120], * dp_float = dp_float_base + 120; + + longword L_max, L_power; + word R, S, dmax, scal; + register word temp; + + /* Search of the optimum scaling of d[0..39]. + */ + dmax = 0; + + for (k = 0; k <= 39; k++) { + temp = d[k]; + temp = GSM_ABS( temp ); + if (temp > dmax) dmax = temp; + } + + temp = 0; + if (dmax == 0) scal = 0; + else { + assert(dmax > 0); + temp = gsm_norm( (longword)dmax << 16 ); + } + + if (temp > 6) scal = 0; + else scal = 6 - temp; + + assert(scal >= 0); + ltp_cut = (longword)SASR(dmax, scal) * st->ltp_cut / 100; + + + /* Initialization of a working array wt + */ + + for (k = 0; k < 40; k++) { + register word w = SASR( d[k], scal ); + if (w < 0 ? w > -ltp_cut : w < ltp_cut) { + wt_float[k] = 0.0; + } + else { + wt_float[k] = w; + } + } + for (k = -120; k < 0; k++) dp_float[k] = dp[k]; + + /* Search for the maximum cross-correlation and coding of the LTP lag + */ + L_max = 0; + Nc = 40; /* index for the maximum cross-correlation */ + + for (lambda = 40; lambda <= 120; lambda += 9) { + + /* Calculate L_result for l = lambda .. lambda + 9. + */ + register float *lp = dp_float - lambda; + + register float W; + register float a = lp[-8], b = lp[-7], c = lp[-6], + d = lp[-5], e = lp[-4], f = lp[-3], + g = lp[-2], h = lp[-1]; + register float E; + register float S0 = 0, S1 = 0, S2 = 0, S3 = 0, S4 = 0, + S5 = 0, S6 = 0, S7 = 0, S8 = 0; + +# undef STEP +# define STEP(K, a, b, c, d, e, f, g, h) \ + if ((W = wt_float[K]) != 0.0) { \ + E = W * a; S8 += E; \ + E = W * b; S7 += E; \ + E = W * c; S6 += E; \ + E = W * d; S5 += E; \ + E = W * e; S4 += E; \ + E = W * f; S3 += E; \ + E = W * g; S2 += E; \ + E = W * h; S1 += E; \ + a = lp[K]; \ + E = W * a; S0 += E; } else (a = lp[K]) + +# define STEP_A(K) STEP(K, a, b, c, d, e, f, g, h) +# define STEP_B(K) STEP(K, b, c, d, e, f, g, h, a) +# define STEP_C(K) STEP(K, c, d, e, f, g, h, a, b) +# define STEP_D(K) STEP(K, d, e, f, g, h, a, b, c) +# define STEP_E(K) STEP(K, e, f, g, h, a, b, c, d) +# define STEP_F(K) STEP(K, f, g, h, a, b, c, d, e) +# define STEP_G(K) STEP(K, g, h, a, b, c, d, e, f) +# define STEP_H(K) STEP(K, h, a, b, c, d, e, f, g) + + STEP_A( 0); STEP_B( 1); STEP_C( 2); STEP_D( 3); + STEP_E( 4); STEP_F( 5); STEP_G( 6); STEP_H( 7); + + STEP_A( 8); STEP_B( 9); STEP_C(10); STEP_D(11); + STEP_E(12); STEP_F(13); STEP_G(14); STEP_H(15); + + STEP_A(16); STEP_B(17); STEP_C(18); STEP_D(19); + STEP_E(20); STEP_F(21); STEP_G(22); STEP_H(23); + + STEP_A(24); STEP_B(25); STEP_C(26); STEP_D(27); + STEP_E(28); STEP_F(29); STEP_G(30); STEP_H(31); + + STEP_A(32); STEP_B(33); STEP_C(34); STEP_D(35); + STEP_E(36); STEP_F(37); STEP_G(38); STEP_H(39); + + if (S0 > L_max) { L_max = S0; Nc = lambda; } + if (S1 > L_max) { L_max = S1; Nc = lambda + 1; } + if (S2 > L_max) { L_max = S2; Nc = lambda + 2; } + if (S3 > L_max) { L_max = S3; Nc = lambda + 3; } + if (S4 > L_max) { L_max = S4; Nc = lambda + 4; } + if (S5 > L_max) { L_max = S5; Nc = lambda + 5; } + if (S6 > L_max) { L_max = S6; Nc = lambda + 6; } + if (S7 > L_max) { L_max = S7; Nc = lambda + 7; } + if (S8 > L_max) { L_max = S8; Nc = lambda + 8; } + + } + *Nc_out = Nc; + + L_max <<= 1; + + /* Rescaling of L_max + */ + assert(scal <= 100 && scal >= -100); + L_max = L_max >> (6 - scal); /* sub(6, scal) */ + + assert( Nc <= 120 && Nc >= 40); + + /* Compute the power of the reconstructed short term residual + * signal dp[..] + */ + L_power = 0; + for (k = 0; k <= 39; k++) { + + register longword L_temp; + + L_temp = SASR( dp[k - Nc], 3 ); + L_power += L_temp * L_temp; + } + L_power <<= 1; /* from L_MULT */ + + /* Normalization of L_max and L_power + */ + + if (L_max <= 0) { + *bc_out = 0; + return; + } + if (L_max >= L_power) { + *bc_out = 3; + return; + } + + temp = gsm_norm( L_power ); + + R = SASR( L_max << temp, 16 ); + S = SASR( L_power << temp, 16 ); + + /* Coding of the LTP gain + */ + + /* Table 4.3a must be used to obtain the level DLB[i] for the + * quantization of the LTP gain b to get the coded version bc. + */ + for (bc = 0; bc <= 2; bc++) if (R <= gsm_mult(S, gsm_DLB[bc])) break; + *bc_out = bc; +} + +#endif /* LTP_CUT */ + +static void Calculation_of_the_LTP_parameters P4((d,dp,bc_out,Nc_out), + register word * d, /* [0..39] IN */ + register word * dp, /* [-120..-1] IN */ + word * bc_out, /* OUT */ + word * Nc_out /* OUT */ +) +{ + register int k, lambda; + word Nc, bc; + + float wt_float[40]; + float dp_float_base[120], * dp_float = dp_float_base + 120; + + longword L_max, L_power; + word R, S, dmax, scal; + register word temp; + + /* Search of the optimum scaling of d[0..39]. + */ + dmax = 0; + + for (k = 0; k <= 39; k++) { + temp = d[k]; + temp = GSM_ABS( temp ); + if (temp > dmax) dmax = temp; + } + + temp = 0; + if (dmax == 0) scal = 0; + else { + assert(dmax > 0); + temp = gsm_norm( (longword)dmax << 16 ); + } + + if (temp > 6) scal = 0; + else scal = 6 - temp; + + assert(scal >= 0); + + /* Initialization of a working array wt + */ + + for (k = 0; k < 40; k++) wt_float[k] = SASR( d[k], scal ); + for (k = -120; k < 0; k++) dp_float[k] = dp[k]; + + /* Search for the maximum cross-correlation and coding of the LTP lag + */ + L_max = 0; + Nc = 40; /* index for the maximum cross-correlation */ + + for (lambda = 40; lambda <= 120; lambda += 9) { + + /* Calculate L_result for l = lambda .. lambda + 9. + */ + register float *lp = dp_float - lambda; + + register float W; + register float a = lp[-8], b = lp[-7], c = lp[-6], + d = lp[-5], e = lp[-4], f = lp[-3], + g = lp[-2], h = lp[-1]; + register float E; + register float S0 = 0, S1 = 0, S2 = 0, S3 = 0, S4 = 0, + S5 = 0, S6 = 0, S7 = 0, S8 = 0; + +# undef STEP +# define STEP(K, a, b, c, d, e, f, g, h) \ + W = wt_float[K]; \ + E = W * a; S8 += E; \ + E = W * b; S7 += E; \ + E = W * c; S6 += E; \ + E = W * d; S5 += E; \ + E = W * e; S4 += E; \ + E = W * f; S3 += E; \ + E = W * g; S2 += E; \ + E = W * h; S1 += E; \ + a = lp[K]; \ + E = W * a; S0 += E + +# define STEP_A(K) STEP(K, a, b, c, d, e, f, g, h) +# define STEP_B(K) STEP(K, b, c, d, e, f, g, h, a) +# define STEP_C(K) STEP(K, c, d, e, f, g, h, a, b) +# define STEP_D(K) STEP(K, d, e, f, g, h, a, b, c) +# define STEP_E(K) STEP(K, e, f, g, h, a, b, c, d) +# define STEP_F(K) STEP(K, f, g, h, a, b, c, d, e) +# define STEP_G(K) STEP(K, g, h, a, b, c, d, e, f) +# define STEP_H(K) STEP(K, h, a, b, c, d, e, f, g) + + STEP_A( 0); STEP_B( 1); STEP_C( 2); STEP_D( 3); + STEP_E( 4); STEP_F( 5); STEP_G( 6); STEP_H( 7); + + STEP_A( 8); STEP_B( 9); STEP_C(10); STEP_D(11); + STEP_E(12); STEP_F(13); STEP_G(14); STEP_H(15); + + STEP_A(16); STEP_B(17); STEP_C(18); STEP_D(19); + STEP_E(20); STEP_F(21); STEP_G(22); STEP_H(23); + + STEP_A(24); STEP_B(25); STEP_C(26); STEP_D(27); + STEP_E(28); STEP_F(29); STEP_G(30); STEP_H(31); + + STEP_A(32); STEP_B(33); STEP_C(34); STEP_D(35); + STEP_E(36); STEP_F(37); STEP_G(38); STEP_H(39); + + if (S0 > L_max) { L_max = S0; Nc = lambda; } + if (S1 > L_max) { L_max = S1; Nc = lambda + 1; } + if (S2 > L_max) { L_max = S2; Nc = lambda + 2; } + if (S3 > L_max) { L_max = S3; Nc = lambda + 3; } + if (S4 > L_max) { L_max = S4; Nc = lambda + 4; } + if (S5 > L_max) { L_max = S5; Nc = lambda + 5; } + if (S6 > L_max) { L_max = S6; Nc = lambda + 6; } + if (S7 > L_max) { L_max = S7; Nc = lambda + 7; } + if (S8 > L_max) { L_max = S8; Nc = lambda + 8; } + } + *Nc_out = Nc; + + L_max <<= 1; + + /* Rescaling of L_max + */ + assert(scal <= 100 && scal >= -100); + L_max = L_max >> (6 - scal); /* sub(6, scal) */ + + assert( Nc <= 120 && Nc >= 40); + + /* Compute the power of the reconstructed short term residual + * signal dp[..] + */ + L_power = 0; + for (k = 0; k <= 39; k++) { + + register longword L_temp; + + L_temp = SASR( dp[k - Nc], 3 ); + L_power += L_temp * L_temp; + } + L_power <<= 1; /* from L_MULT */ + + /* Normalization of L_max and L_power + */ + + if (L_max <= 0) { + *bc_out = 0; + return; + } + if (L_max >= L_power) { + *bc_out = 3; + return; + } + + temp = gsm_norm( L_power ); + + R = SASR( L_max << temp, 16 ); + S = SASR( L_power << temp, 16 ); + + /* Coding of the LTP gain + */ + + /* Table 4.3a must be used to obtain the level DLB[i] for the + * quantization of the LTP gain b to get the coded version bc. + */ + for (bc = 0; bc <= 2; bc++) if (R <= gsm_mult(S, gsm_DLB[bc])) break; + *bc_out = bc; +} + +#ifdef FAST +#ifdef LTP_CUT + +static void Cut_Fast_Calculation_of_the_LTP_parameters P5((st, + d,dp,bc_out,Nc_out), + struct gsm_state * st, /* IN */ + register word * d, /* [0..39] IN */ + register word * dp, /* [-120..-1] IN */ + word * bc_out, /* OUT */ + word * Nc_out /* OUT */ +) +{ + register int k, lambda; + register float wt_float; + word Nc, bc; + word wt_max, best_k, ltp_cut; + + float dp_float_base[120], * dp_float = dp_float_base + 120; + + register float L_result, L_max, L_power; + + wt_max = 0; + + for (k = 0; k < 40; ++k) { + if ( d[k] > wt_max) wt_max = d[best_k = k]; + else if (-d[k] > wt_max) wt_max = -d[best_k = k]; + } + + assert(wt_max >= 0); + wt_float = (float)wt_max; + + for (k = -120; k < 0; ++k) dp_float[k] = (float)dp[k]; + + /* Search for the maximum cross-correlation and coding of the LTP lag + */ + L_max = 0; + Nc = 40; /* index for the maximum cross-correlation */ + + for (lambda = 40; lambda <= 120; lambda++) { + L_result = wt_float * dp_float[best_k - lambda]; + if (L_result > L_max) { + Nc = lambda; + L_max = L_result; + } + } + + *Nc_out = Nc; + if (L_max <= 0.) { + *bc_out = 0; + return; + } + + /* Compute the power of the reconstructed short term residual + * signal dp[..] + */ + dp_float -= Nc; + L_power = 0; + for (k = 0; k < 40; ++k) { + register float f = dp_float[k]; + L_power += f * f; + } + + if (L_max >= L_power) { + *bc_out = 3; + return; + } + + /* Coding of the LTP gain + * Table 4.3a must be used to obtain the level DLB[i] for the + * quantization of the LTP gain b to get the coded version bc. + */ + lambda = L_max / L_power * 32768.; + for (bc = 0; bc <= 2; ++bc) if (lambda <= gsm_DLB[bc]) break; + *bc_out = bc; +} + +#endif /* LTP_CUT */ + +static void Fast_Calculation_of_the_LTP_parameters P4((d,dp,bc_out,Nc_out), + register word * d, /* [0..39] IN */ + register word * dp, /* [-120..-1] IN */ + word * bc_out, /* OUT */ + word * Nc_out /* OUT */ +) +{ + register int k, lambda; + word Nc, bc; + + float wt_float[40]; + float dp_float_base[120], * dp_float = dp_float_base + 120; + + register float L_max, L_power; + + for (k = 0; k < 40; ++k) wt_float[k] = (float)d[k]; + for (k = -120; k < 0; ++k) dp_float[k] = (float)dp[k]; + + /* Search for the maximum cross-correlation and coding of the LTP lag + */ + L_max = 0; + Nc = 40; /* index for the maximum cross-correlation */ + + for (lambda = 40; lambda <= 120; lambda += 9) { + + /* Calculate L_result for l = lambda .. lambda + 9. + */ + register float *lp = dp_float - lambda; + + register float W; + register float a = lp[-8], b = lp[-7], c = lp[-6], + d = lp[-5], e = lp[-4], f = lp[-3], + g = lp[-2], h = lp[-1]; + register float E; + register float S0 = 0, S1 = 0, S2 = 0, S3 = 0, S4 = 0, + S5 = 0, S6 = 0, S7 = 0, S8 = 0; + +# undef STEP +# define STEP(K, a, b, c, d, e, f, g, h) \ + W = wt_float[K]; \ + E = W * a; S8 += E; \ + E = W * b; S7 += E; \ + E = W * c; S6 += E; \ + E = W * d; S5 += E; \ + E = W * e; S4 += E; \ + E = W * f; S3 += E; \ + E = W * g; S2 += E; \ + E = W * h; S1 += E; \ + a = lp[K]; \ + E = W * a; S0 += E + +# define STEP_A(K) STEP(K, a, b, c, d, e, f, g, h) +# define STEP_B(K) STEP(K, b, c, d, e, f, g, h, a) +# define STEP_C(K) STEP(K, c, d, e, f, g, h, a, b) +# define STEP_D(K) STEP(K, d, e, f, g, h, a, b, c) +# define STEP_E(K) STEP(K, e, f, g, h, a, b, c, d) +# define STEP_F(K) STEP(K, f, g, h, a, b, c, d, e) +# define STEP_G(K) STEP(K, g, h, a, b, c, d, e, f) +# define STEP_H(K) STEP(K, h, a, b, c, d, e, f, g) + + STEP_A( 0); STEP_B( 1); STEP_C( 2); STEP_D( 3); + STEP_E( 4); STEP_F( 5); STEP_G( 6); STEP_H( 7); + + STEP_A( 8); STEP_B( 9); STEP_C(10); STEP_D(11); + STEP_E(12); STEP_F(13); STEP_G(14); STEP_H(15); + + STEP_A(16); STEP_B(17); STEP_C(18); STEP_D(19); + STEP_E(20); STEP_F(21); STEP_G(22); STEP_H(23); + + STEP_A(24); STEP_B(25); STEP_C(26); STEP_D(27); + STEP_E(28); STEP_F(29); STEP_G(30); STEP_H(31); + + STEP_A(32); STEP_B(33); STEP_C(34); STEP_D(35); + STEP_E(36); STEP_F(37); STEP_G(38); STEP_H(39); + + if (S0 > L_max) { L_max = S0; Nc = lambda; } + if (S1 > L_max) { L_max = S1; Nc = lambda + 1; } + if (S2 > L_max) { L_max = S2; Nc = lambda + 2; } + if (S3 > L_max) { L_max = S3; Nc = lambda + 3; } + if (S4 > L_max) { L_max = S4; Nc = lambda + 4; } + if (S5 > L_max) { L_max = S5; Nc = lambda + 5; } + if (S6 > L_max) { L_max = S6; Nc = lambda + 6; } + if (S7 > L_max) { L_max = S7; Nc = lambda + 7; } + if (S8 > L_max) { L_max = S8; Nc = lambda + 8; } + } + *Nc_out = Nc; + + if (L_max <= 0.) { + *bc_out = 0; + return; + } + + /* Compute the power of the reconstructed short term residual + * signal dp[..] + */ + dp_float -= Nc; + L_power = 0; + for (k = 0; k < 40; ++k) { + register float f = dp_float[k]; + L_power += f * f; + } + + if (L_max >= L_power) { + *bc_out = 3; + return; + } + + /* Coding of the LTP gain + * Table 4.3a must be used to obtain the level DLB[i] for the + * quantization of the LTP gain b to get the coded version bc. + */ + lambda = L_max / L_power * 32768.; + for (bc = 0; bc <= 2; ++bc) if (lambda <= gsm_DLB[bc]) break; + *bc_out = bc; +} + +#endif /* FAST */ +#endif /* USE_FLOAT_MUL */ + + +/* 4.2.12 */ + +static void Long_term_analysis_filtering P6((bc,Nc,dp,d,dpp,e), + word bc, /* IN */ + word Nc, /* IN */ + register word * dp, /* previous d [-120..-1] IN */ + register word * d, /* d [0..39] IN */ + register word * dpp, /* estimate [0..39] OUT */ + register word * e /* long term res. signal [0..39] OUT */ +) +/* + * In this part, we have to decode the bc parameter to compute + * the samples of the estimate dpp[0..39]. The decoding of bc needs the + * use of table 4.3b. The long term residual signal e[0..39] + * is then calculated to be fed to the RPE encoding section. + */ +{ + register int k; + register longword ltmp; + +# undef STEP +# define STEP(BP) \ + for (k = 0; k <= 39; k++) { \ + dpp[k] = GSM_MULT_R( BP, dp[k - Nc]); \ + e[k] = GSM_SUB( d[k], dpp[k] ); \ + } + + switch (bc) { + case 0: STEP( 3277 ); break; + case 1: STEP( 11469 ); break; + case 2: STEP( 21299 ); break; + case 3: STEP( 32767 ); break; + } +} + +void Gsm_Long_Term_Predictor P7((S,d,dp,e,dpp,Nc,bc), /* 4x for 160 samples */ + + struct gsm_state * S, + + word * d, /* [0..39] residual signal IN */ + word * dp, /* [-120..-1] d' IN */ + + word * e, /* [0..39] OUT */ + word * dpp, /* [0..39] OUT */ + word * Nc, /* correlation lag OUT */ + word * bc /* gain factor OUT */ +) +{ + assert( d ); assert( dp ); assert( e ); + assert( dpp); assert( Nc ); assert( bc ); + +#if defined(FAST) && defined(USE_FLOAT_MUL) + if (S->fast) +#if defined (LTP_CUT) + if (S->ltp_cut) + Cut_Fast_Calculation_of_the_LTP_parameters(S, + d, dp, bc, Nc); + else +#endif /* LTP_CUT */ + Fast_Calculation_of_the_LTP_parameters(d, dp, bc, Nc ); + else +#endif /* FAST & USE_FLOAT_MUL */ +#ifdef LTP_CUT + if (S->ltp_cut) + Cut_Calculation_of_the_LTP_parameters(S, d, dp, bc, Nc); + else +#endif + Calculation_of_the_LTP_parameters(d, dp, bc, Nc); + + Long_term_analysis_filtering( *bc, *Nc, dp, d, dpp, e ); +} + +/* 4.3.2 */ +void Gsm_Long_Term_Synthesis_Filtering P5((S,Ncr,bcr,erp,drp), + struct gsm_state * S, + + word Ncr, + word bcr, + register word * erp, /* [0..39] IN */ + register word * drp /* [-120..-1] IN, [-120..40] OUT */ +) +/* + * This procedure uses the bcr and Ncr parameter to realize the + * long term synthesis filtering. The decoding of bcr needs + * table 4.3b. + */ +{ + register longword ltmp; /* for ADD */ + register int k; + word brp, drpp, Nr; + + /* Check the limits of Nr. + */ + Nr = Ncr < 40 || Ncr > 120 ? S->nrp : Ncr; + S->nrp = Nr; + assert(Nr >= 40 && Nr <= 120); + + /* Decoding of the LTP gain bcr + */ + brp = gsm_QLB[ bcr ]; + + /* Computation of the reconstructed short term residual + * signal drp[0..39] + */ + assert(brp != MIN_WORD); + + for (k = 0; k <= 39; k++) { + drpp = GSM_MULT_R( brp, drp[ k - Nr ] ); + drp[k] = GSM_ADD( erp[k], drpp ); + } + + /* + * Update of the reconstructed short term residual signal + * drp[ -1..-120 ] + */ + + for (k = 0; k <= 119; k++) drp[ -120 + k ] = drp[ -80 + k ]; +} |