| /* |
| * 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: /tmp_amd/presto/export/kbs/jutta/src/gsm/RCS/long_term.c,v 1.6 1996/07/02 12:33:19 jutta Exp $ */ |
| |
| #include "config.h" |
| #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 ]; |
| } |