--- /dev/null
+/*
+ * 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 <stdio.h>
+#include <assert.h>
+
+#include "gsm610_priv.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 (
+
+ 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_W(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_W( 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 (
+ 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_W( 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_W( 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( L_max << temp, 16 );
+ S = SASR_L( 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 (
+ 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_W(dmax, scal) * st->ltp_cut / 100;
+
+
+ /* Initialization of a working array wt
+ */
+
+ for (k = 0; k < 40; k++) {
+ register word w = SASR_W( 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);
+
+# undef STEP_A
+# undef STEP_B
+# undef STEP_C
+# undef STEP_D
+# undef STEP_E
+# undef STEP_F
+# undef STEP_G
+# undef STEP_H
+
+ 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_W( 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 (
+ register word * din, /* [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 = din [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_W (din [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);
+
+# undef STEP_A
+# undef STEP_B
+# undef STEP_C
+# undef STEP_D
+# undef STEP_E
+# undef STEP_F
+# undef STEP_G
+# undef STEP_H
+
+ 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_W( 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 ( L_max << temp, 16 );
+ S = SASR_L ( 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 (
+ 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 (
+ register word * din, /* [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) din [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 (
+ 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;
+
+# 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 ( /* 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 (
+ 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 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 ];
+}
projects / Faustine.git / blobdiff