+++ /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"
-
-/* 4.2.13 .. 4.2.17 RPE ENCODING SECTION
- */
-
-/* 4.2.13 */
-
-static void Weighting_filter (
- register word * e, /* signal [-5..0.39.44] IN */
- word * x /* signal [0..39] OUT */
-)
-/*
- * The coefficients of the weighting filter are stored in a table
- * (see table 4.4). The following scaling is used:
- *
- * H[0..10] = integer( real_H[ 0..10] * 8192 );
- */
-{
- /* word wt[ 50 ]; */
-
- register longword L_result;
- register int k /* , i */ ;
-
- /* Initialization of a temporary working array wt[0...49]
- */
-
- /* for (k = 0; k <= 4; k++) wt[k] = 0;
- * for (k = 5; k <= 44; k++) wt[k] = *e++;
- * for (k = 45; k <= 49; k++) wt[k] = 0;
- *
- * (e[-5..-1] and e[40..44] are allocated by the caller,
- * are initially zero and are not written anywhere.)
- */
- e -= 5;
-
- /* Compute the signal x[0..39]
- */
- for (k = 0; k <= 39; k++) {
-
- L_result = 8192 >> 1;
-
- /* for (i = 0; i <= 10; i++) {
- * L_temp = GSM_L_MULT( wt[k+i], gsm_H[i] );
- * L_result = GSM_L_ADD( L_result, L_temp );
- * }
- */
-
-#undef STEP
-#define STEP( i, H ) (e[ k + i ] * (longword)H)
-
- /* Every one of these multiplications is done twice --
- * but I don't see an elegant way to optimize this.
- * Do you?
- */
-
-#ifdef STUPID_COMPILER
- L_result += STEP( 0, -134 ) ;
- L_result += STEP( 1, -374 ) ;
- /* + STEP( 2, 0 ) */
- L_result += STEP( 3, 2054 ) ;
- L_result += STEP( 4, 5741 ) ;
- L_result += STEP( 5, 8192 ) ;
- L_result += STEP( 6, 5741 ) ;
- L_result += STEP( 7, 2054 ) ;
- /* + STEP( 8, 0 ) */
- L_result += STEP( 9, -374 ) ;
- L_result += STEP( 10, -134 ) ;
-#else
- L_result +=
- STEP( 0, -134 )
- + STEP( 1, -374 )
- /* + STEP( 2, 0 ) */
- + STEP( 3, 2054 )
- + STEP( 4, 5741 )
- + STEP( 5, 8192 )
- + STEP( 6, 5741 )
- + STEP( 7, 2054 )
- /* + STEP( 8, 0 ) */
- + STEP( 9, -374 )
- + STEP(10, -134 )
- ;
-#endif
-
- /* L_result = GSM_L_ADD( L_result, L_result ); (* scaling(x2) *)
- * L_result = GSM_L_ADD( L_result, L_result ); (* scaling(x4) *)
- *
- * x[k] = SASR( L_result, 16 );
- */
-
- /* 2 adds vs. >>16 => 14, minus one shift to compensate for
- * those we lost when replacing L_MULT by '*'.
- */
-
- L_result = SASR_L( L_result, 13 );
- x[k] = ( L_result < MIN_WORD ? MIN_WORD
- : (L_result > MAX_WORD ? MAX_WORD : L_result ));
- }
-}
-
-/* 4.2.14 */
-
-static void RPE_grid_selection (
- word * x, /* [0..39] IN */
- word * xM, /* [0..12] OUT */
- word * Mc_out /* OUT */
-)
-/*
- * The signal x[0..39] is used to select the RPE grid which is
- * represented by Mc.
- */
-{
- /* register word temp1; */
- register int /* m, */ i;
- register longword L_result, L_temp;
- longword EM; /* xxx should be L_EM? */
- word Mc;
-
- longword L_common_0_3;
-
- EM = 0;
- Mc = 0;
-
- /* for (m = 0; m <= 3; m++) {
- * L_result = 0;
- *
- *
- * for (i = 0; i <= 12; i++) {
- *
- * temp1 = SASR_W( x[m + 3*i], 2 );
- *
- * assert(temp1 != MIN_WORD);
- *
- * L_temp = GSM_L_MULT( temp1, temp1 );
- * L_result = GSM_L_ADD( L_temp, L_result );
- * }
- *
- * if (L_result > EM) {
- * Mc = m;
- * EM = L_result;
- * }
- * }
- */
-
-#undef STEP
-#define STEP( m, i ) L_temp = SASR_W( x[m + 3 * i], 2 ); \
- L_result += L_temp * L_temp;
-
- /* common part of 0 and 3 */
-
- L_result = 0;
- STEP( 0, 1 ); STEP( 0, 2 ); STEP( 0, 3 ); STEP( 0, 4 );
- STEP( 0, 5 ); STEP( 0, 6 ); STEP( 0, 7 ); STEP( 0, 8 );
- STEP( 0, 9 ); STEP( 0, 10); STEP( 0, 11); STEP( 0, 12);
- L_common_0_3 = L_result;
-
- /* i = 0 */
-
- STEP( 0, 0 );
- L_result <<= 1; /* implicit in L_MULT */
- EM = L_result;
-
- /* i = 1 */
-
- L_result = 0;
- STEP( 1, 0 );
- STEP( 1, 1 ); STEP( 1, 2 ); STEP( 1, 3 ); STEP( 1, 4 );
- STEP( 1, 5 ); STEP( 1, 6 ); STEP( 1, 7 ); STEP( 1, 8 );
- STEP( 1, 9 ); STEP( 1, 10); STEP( 1, 11); STEP( 1, 12);
- L_result <<= 1;
- if (L_result > EM) {
- Mc = 1;
- EM = L_result;
- }
-
- /* i = 2 */
-
- L_result = 0;
- STEP( 2, 0 );
- STEP( 2, 1 ); STEP( 2, 2 ); STEP( 2, 3 ); STEP( 2, 4 );
- STEP( 2, 5 ); STEP( 2, 6 ); STEP( 2, 7 ); STEP( 2, 8 );
- STEP( 2, 9 ); STEP( 2, 10); STEP( 2, 11); STEP( 2, 12);
- L_result <<= 1;
- if (L_result > EM) {
- Mc = 2;
- EM = L_result;
- }
-
- /* i = 3 */
-
- L_result = L_common_0_3;
- STEP( 3, 12 );
- L_result <<= 1;
- if (L_result > EM) {
- Mc = 3;
- EM = L_result;
- }
-
- /**/
-
- /* Down-sampling by a factor 3 to get the selected xM[0..12]
- * RPE sequence.
- */
- for (i = 0; i <= 12; i ++) xM[i] = x[Mc + 3*i];
- *Mc_out = Mc;
-}
-
-/* 4.12.15 */
-
-static void APCM_quantization_xmaxc_to_exp_mant (
- word xmaxc, /* IN */
- word * expon_out, /* OUT */
- word * mant_out ) /* OUT */
-{
- word expon, mant;
-
- /* Compute expononent and mantissa of the decoded version of xmaxc
- */
-
- expon = 0;
- if (xmaxc > 15) expon = SASR_W(xmaxc, 3) - 1;
- mant = xmaxc - (expon << 3);
-
- if (mant == 0) {
- expon = -4;
- mant = 7;
- }
- else {
- while (mant <= 7) {
- mant = mant << 1 | 1;
- expon--;
- }
- mant -= 8;
- }
-
- assert( expon >= -4 && expon <= 6 );
- assert( mant >= 0 && mant <= 7 );
-
- *expon_out = expon;
- *mant_out = mant;
-}
-
-static void APCM_quantization (
- word * xM, /* [0..12] IN */
- word * xMc, /* [0..12] OUT */
- word * mant_out, /* OUT */
- word * expon_out, /* OUT */
- word * xmaxc_out /* OUT */
-)
-{
- int i, itest;
-
- word xmax, xmaxc, temp, temp1, temp2;
- word expon, mant;
-
-
- /* Find the maximum absolute value xmax of xM[0..12].
- */
-
- xmax = 0;
- for (i = 0; i <= 12; i++) {
- temp = xM[i];
- temp = GSM_ABS(temp);
- if (temp > xmax) xmax = temp;
- }
-
- /* Qantizing and coding of xmax to get xmaxc.
- */
-
- expon = 0;
- temp = SASR_W( xmax, 9 );
- itest = 0;
-
- for (i = 0; i <= 5; i++) {
-
- itest |= (temp <= 0);
- temp = SASR_W( temp, 1 );
-
- assert(expon <= 5);
- if (itest == 0) expon++; /* expon = add (expon, 1) */
- }
-
- assert(expon <= 6 && expon >= 0);
- temp = expon + 5;
-
- assert(temp <= 11 && temp >= 0);
- xmaxc = gsm_add( SASR_W(xmax, temp), (word) (expon << 3) );
-
- /* Quantizing and coding of the xM[0..12] RPE sequence
- * to get the xMc[0..12]
- */
-
- APCM_quantization_xmaxc_to_exp_mant( xmaxc, &expon, &mant );
-
- /* This computation uses the fact that the decoded version of xmaxc
- * can be calculated by using the expononent and the mantissa part of
- * xmaxc (logarithmic table).
- * So, this method avoids any division and uses only a scaling
- * of the RPE samples by a function of the expononent. A direct
- * multiplication by the inverse of the mantissa (NRFAC[0..7]
- * found in table 4.5) gives the 3 bit coded version xMc[0..12]
- * of the RPE samples.
- */
-
-
- /* Direct computation of xMc[0..12] using table 4.5
- */
-
- assert( expon <= 4096 && expon >= -4096);
- assert( mant >= 0 && mant <= 7 );
-
- temp1 = 6 - expon; /* normalization by the expononent */
- temp2 = gsm_NRFAC[ mant ]; /* inverse mantissa */
-
- for (i = 0; i <= 12; i++) {
-
- assert(temp1 >= 0 && temp1 < 16);
-
- temp = xM[i] << temp1;
- temp = GSM_MULT( temp, temp2 );
- temp = SASR_W(temp, 12);
- xMc[i] = temp + 4; /* see note below */
- }
-
- /* NOTE: This equation is used to make all the xMc[i] positive.
- */
-
- *mant_out = mant;
- *expon_out = expon;
- *xmaxc_out = xmaxc;
-}
-
-/* 4.2.16 */
-
-static void APCM_inverse_quantization (
- register word * xMc, /* [0..12] IN */
- word mant,
- word expon,
- register word * xMp) /* [0..12] OUT */
-/*
- * This part is for decoding the RPE sequence of coded xMc[0..12]
- * samples to obtain the xMp[0..12] array. Table 4.6 is used to get
- * the mantissa of xmaxc (FAC[0..7]).
- */
-{
- int i;
- word temp, temp1, temp2, temp3;
-
- assert( mant >= 0 && mant <= 7 );
-
- temp1 = gsm_FAC[ mant ]; /* see 4.2-15 for mant */
- temp2 = gsm_sub( 6, expon ); /* see 4.2-15 for exp */
- temp3 = gsm_asl( 1, gsm_sub( temp2, 1 ));
-
- for (i = 13; i--;) {
-
- assert( *xMc <= 7 && *xMc >= 0 ); /* 3 bit unsigned */
-
- /* temp = gsm_sub( *xMc++ << 1, 7 ); */
- temp = (*xMc++ << 1) - 7; /* restore sign */
- assert( temp <= 7 && temp >= -7 ); /* 4 bit signed */
-
- temp <<= 12; /* 16 bit signed */
- temp = GSM_MULT_R( temp1, temp );
- temp = GSM_ADD( temp, temp3 );
- *xMp++ = gsm_asr( temp, temp2 );
- }
-}
-
-/* 4.2.17 */
-
-static void RPE_grid_positioning (
- word Mc, /* grid position IN */
- register word * xMp, /* [0..12] IN */
- register word * ep /* [0..39] OUT */
-)
-/*
- * This procedure computes the reconstructed long term residual signal
- * ep[0..39] for the LTP analysis filter. The inputs are the Mc
- * which is the grid position selection and the xMp[0..12] decoded
- * RPE samples which are upsampled by a factor of 3 by inserting zero
- * values.
- */
-{
- int i = 13;
-
- assert(0 <= Mc && Mc <= 3);
-
- switch (Mc) {
- case 3: *ep++ = 0;
- case 2: do {
- *ep++ = 0;
- case 1: *ep++ = 0;
- case 0: *ep++ = *xMp++;
- } while (--i);
- }
- while (++Mc < 4) *ep++ = 0;
-
- /*
-
- int i, k;
- for (k = 0; k <= 39; k++) ep[k] = 0;
- for (i = 0; i <= 12; i++) {
- ep[ Mc + (3*i) ] = xMp[i];
- }
- */
-}
-
-/* 4.2.18 */
-
-/* This procedure adds the reconstructed long term residual signal
- * ep[0..39] to the estimated signal dpp[0..39] from the long term
- * analysis filter to compute the reconstructed short term residual
- * signal dp[-40..-1]; also the reconstructed short term residual
- * array dp[-120..-41] is updated.
- */
-
-#if 0 /* Has been inlined in code.c */
-void Gsm_Update_of_reconstructed_short_time_residual_signal (
- word * dpp, /* [0...39] IN */
- word * ep, /* [0...39] IN */
- word * dp) /* [-120...-1] IN/OUT */
-{
- int k;
-
- for (k = 0; k <= 79; k++)
- dp[ -120 + k ] = dp[ -80 + k ];
-
- for (k = 0; k <= 39; k++)
- dp[ -40 + k ] = gsm_add( ep[k], dpp[k] );
-}
-#endif /* Has been inlined in code.c */
-
-void Gsm_RPE_Encoding (
- /*-struct gsm_state * S,-*/
-
- word * e, /* -5..-1][0..39][40..44 IN/OUT */
- word * xmaxc, /* OUT */
- word * Mc, /* OUT */
- word * xMc) /* [0..12] OUT */
-{
- word x[40];
- word xM[13], xMp[13];
- word mant, expon;
-
- Weighting_filter(e, x);
- RPE_grid_selection(x, xM, Mc);
-
- APCM_quantization( xM, xMc, &mant, &expon, xmaxc);
- APCM_inverse_quantization( xMc, mant, expon, xMp);
-
- RPE_grid_positioning( *Mc, xMp, e );
-
-}
-
-void Gsm_RPE_Decoding (
- /*-struct gsm_state * S,-*/
-
- word xmaxcr,
- word Mcr,
- word * xMcr, /* [0..12], 3 bits IN */
- word * erp /* [0..39] OUT */
-)
-{
- word expon, mant;
- word xMp[ 13 ];
-
- APCM_quantization_xmaxc_to_exp_mant( xmaxcr, &expon, &mant );
- APCM_inverse_quantization( xMcr, mant, expon, xMp );
- RPE_grid_positioning( Mcr, xMp, erp );
-
-}
projects / Faustine.git / blobdiff