/* gsm_enc_encode.c */ /* * 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 "../extra.h" #include "private.h" /* * Prototypes from add.c */ extern word gsm_enc_div (word num, word denum); extern word gsm_enc_sub (word a, word b); extern word gsm_enc_norm ( longword a ); extern word gsm_enc_asl (word a, int n); extern word gsm_enc_asr (word a, int n); /* * Inlined functions from add.h */ #define GSM_MULT_R(a, b) /* word a, word b, !(a == b == MIN_WORD) */ \ (SASR( ((longword)(a) * (longword)(b) + 16384), 15 )) # define GSM_MULT(a,b) /* word a, word b, !(a == b == MIN_WORD) */ \ (SASR( ((longword)(a) * (longword)(b)), 15 )) # define GSM_L_ADD(a, b) \ ( (a) < 0 ? ( (b) >= 0 ? (a) + (b) \ : (utmp = (ulongword)-((a) + 1) + (ulongword)-((b) + 1)) \ >= MAX_LONGWORD ? MIN_LONGWORD : -(longword)utmp-2 ) \ : ((b) <= 0 ? (a) + (b) \ : (utmp = (ulongword)(a) + (ulongword)(b)) >= (ulongword)MAX_LONGWORD \ ? MAX_LONGWORD : a + b)) #define GSM_ADD(a, b) \ ((ulongword)((ltmp = (longword)(a) + (longword)(b)) - MIN_WORD) > \ MAX_WORD - MIN_WORD ? (ltmp > 0 ? MAX_WORD : MIN_WORD) : ltmp) # define GSM_SUB(a, b) \ ((ltmp = (longword)(a) - (longword)(b)) >= MAX_WORD \ ? MAX_WORD : ltmp <= MIN_WORD ? MIN_WORD : ltmp) # define GSM_ABS(a) ((a) < 0 ? ((a) == MIN_WORD ? MAX_WORD : -(a)) : (a)) #define saturate(x) \ ((x) < MIN_WORD ? MIN_WORD : (x) > MAX_WORD ? MAX_WORD: (x)) /* Use these if necessary: # define GSM_MULT_R(a, b) gsm_enc_mult_r(a, b) # define GSM_MULT(a, b) gsm_enc_mult(a, b) # define GSM_L_MULT(a, b) gsm_enc_L_mult(a, b) # define GSM_L_ADD(a, b) gsm_enc_L_add(a, b) # define GSM_ADD(a, b) gsm_enc_add(a, b) # define GSM_SUB(a, b) gsm_enc_sub(a, b) # define GSM_ABS(a) gsm_enc_abs(a) */ /* * More prototypes from implementations.. */ extern void gsm_enc_Gsm_Coder ( struct gsm_state * S, word * s, /* [0..159] samples IN */ word * LARc, /* [0..7] LAR coefficients OUT */ word * Nc, /* [0..3] LTP lag OUT */ word * bc, /* [0..3] coded LTP gain OUT */ word * Mc, /* [0..3] RPE grid selection OUT */ word * xmaxc,/* [0..3] Coded maximum amplitude OUT */ word * xMc /* [13*4] normalized RPE samples OUT */); extern void gsm_enc_Gsm_Long_Term_Predictor ( /* 4x for 160 samples */ word * d, /* [0..39] residual signal IN */ word * dp, /* [-120..-1] d' IN */ word * e, /* [0..40] OUT */ word * dpp, /* [0..40] OUT */ word * Nc, /* correlation lag OUT */ word * bc /* gain factor OUT */); extern void gsm_enc_Gsm_LPC_Analysis ( word * s, /* 0..159 signals IN/OUT */ word * LARc); /* 0..7 LARc's OUT */ extern void gsm_enc_Gsm_Preprocess ( struct gsm_state * S, word * s, word * so); extern void gsm_enc_Gsm_Short_Term_Analysis_Filter ( struct gsm_state * S, word * LARc, /* coded log area ratio [0..7] IN */ word * d /* st res. signal [0..159] IN/OUT */); void gsm_enc_Gsm_RPE_Encoding ( word * e, /* -5..-1][0..39][40..44 IN/OUT */ word * xmaxc, /* OUT */ word * Mc, /* OUT */ word * xMc); /* [0..12] OUT */ /**************** end #include "private.h" **********************************/ /* * Interface */ typedef struct gsm_state * gsm; typedef short gsm_signal; /* signed 16 bit */ typedef unsigned char gsm_byte; typedef gsm_byte gsm_frame[33]; /* 33 * 8 bits */ #define GSM_MAGIC 0xD /* 13 kbit/s RPE-LTP */ #define GSM_PATCHLEVEL 6 #define GSM_MINOR 0 #define GSM_MAJOR 1 #include "data.h" extern void gsm_enc_encode (gsm, gsm_signal *, gsm_byte *); extern int gsm_enc_explode (gsm, gsm_byte *, gsm_signal *); extern void gsm_enc_implode (gsm, gsm_signal *, gsm_byte *); /******************* end #include "gsm.h" **********************************/ #define SAMPLES 20 /* Forward declaration of global variables */ struct gsm_state gsm_enc_state; gsm gsm_enc_state_ptr; volatile int gsm_enc_result; /* add.c */ word gsm_enc_sub (word a, word b) { longword diff = (longword)a - (longword)b; return saturate(diff); } unsigned char gsm_enc_bitoff[ 256 ] = { 8, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; void gsm_enc_encode (gsm s, gsm_signal * source, gsm_byte * c) { word LARc[8], Nc[4], Mc[4], bc[4], xmaxc[4], xmc[13*4]; gsm_enc_Gsm_Coder(s, source, LARc, Nc, bc, Mc, xmaxc, xmc); /* variable size GSM_MAGIC 4 LARc[0] 6 LARc[1] 6 LARc[2] 5 LARc[3] 5 LARc[4] 4 LARc[5] 4 LARc[6] 3 LARc[7] 3 Nc[0] 7 bc[0] 2 Mc[0] 2 xmaxc[0] 6 xmc[0] 3 xmc[1] 3 xmc[2] 3 xmc[3] 3 xmc[4] 3 xmc[5] 3 xmc[6] 3 xmc[7] 3 xmc[8] 3 xmc[9] 3 xmc[10] 3 xmc[11] 3 xmc[12] 3 Nc[1] 7 bc[1] 2 Mc[1] 2 xmaxc[1] 6 xmc[13] 3 xmc[14] 3 xmc[15] 3 xmc[16] 3 xmc[17] 3 xmc[18] 3 xmc[19] 3 xmc[20] 3 xmc[21] 3 xmc[22] 3 xmc[23] 3 xmc[24] 3 xmc[25] 3 Nc[2] 7 bc[2] 2 Mc[2] 2 xmaxc[2] 6 xmc[26] 3 xmc[27] 3 xmc[28] 3 xmc[29] 3 xmc[30] 3 xmc[31] 3 xmc[32] 3 xmc[33] 3 xmc[34] 3 xmc[35] 3 xmc[36] 3 xmc[37] 3 xmc[38] 3 Nc[3] 7 bc[3] 2 Mc[3] 2 xmaxc[3] 6 xmc[39] 3 xmc[40] 3 xmc[41] 3 xmc[42] 3 xmc[43] 3 xmc[44] 3 xmc[45] 3 xmc[46] 3 xmc[47] 3 xmc[48] 3 xmc[49] 3 xmc[50] 3 xmc[51] 3 */ *c++ = ((GSM_MAGIC & 0xF) << 4) /* 1 */ | ((LARc[0] >> 2) & 0xF); *c++ = ((LARc[0] & 0x3) << 6) | (LARc[1] & 0x3F); *c++ = ((LARc[2] & 0x1F) << 3) | ((LARc[3] >> 2) & 0x7); *c++ = ((LARc[3] & 0x3) << 6) | ((LARc[4] & 0xF) << 2) | ((LARc[5] >> 2) & 0x3); *c++ = ((LARc[5] & 0x3) << 6) | ((LARc[6] & 0x7) << 3) | (LARc[7] & 0x7); *c++ = ((Nc[0] & 0x7F) << 1) | ((bc[0] >> 1) & 0x1); *c++ = ((bc[0] & 0x1) << 7) | ((Mc[0] & 0x3) << 5) | ((xmaxc[0] >> 1) & 0x1F); *c++ = ((xmaxc[0] & 0x1) << 7) | ((xmc[0] & 0x7) << 4) | ((xmc[1] & 0x7) << 1) | ((xmc[2] >> 2) & 0x1); *c++ = ((xmc[2] & 0x3) << 6) | ((xmc[3] & 0x7) << 3) | (xmc[4] & 0x7); *c++ = ((xmc[5] & 0x7) << 5) /* 10 */ | ((xmc[6] & 0x7) << 2) | ((xmc[7] >> 1) & 0x3); *c++ = ((xmc[7] & 0x1) << 7) | ((xmc[8] & 0x7) << 4) | ((xmc[9] & 0x7) << 1) | ((xmc[10] >> 2) & 0x1); *c++ = ((xmc[10] & 0x3) << 6) | ((xmc[11] & 0x7) << 3) | (xmc[12] & 0x7); *c++ = ((Nc[1] & 0x7F) << 1) | ((bc[1] >> 1) & 0x1); *c++ = ((bc[1] & 0x1) << 7) | ((Mc[1] & 0x3) << 5) | ((xmaxc[1] >> 1) & 0x1F); *c++ = ((xmaxc[1] & 0x1) << 7) | ((xmc[13] & 0x7) << 4) | ((xmc[14] & 0x7) << 1) | ((xmc[15] >> 2) & 0x1); *c++ = ((xmc[15] & 0x3) << 6) | ((xmc[16] & 0x7) << 3) | (xmc[17] & 0x7); *c++ = ((xmc[18] & 0x7) << 5) | ((xmc[19] & 0x7) << 2) | ((xmc[20] >> 1) & 0x3); *c++ = ((xmc[20] & 0x1) << 7) | ((xmc[21] & 0x7) << 4) | ((xmc[22] & 0x7) << 1) | ((xmc[23] >> 2) & 0x1); *c++ = ((xmc[23] & 0x3) << 6) | ((xmc[24] & 0x7) << 3) | (xmc[25] & 0x7); *c++ = ((Nc[2] & 0x7F) << 1) /* 20 */ | ((bc[2] >> 1) & 0x1); *c++ = ((bc[2] & 0x1) << 7) | ((Mc[2] & 0x3) << 5) | ((xmaxc[2] >> 1) & 0x1F); *c++ = ((xmaxc[2] & 0x1) << 7) | ((xmc[26] & 0x7) << 4) | ((xmc[27] & 0x7) << 1) | ((xmc[28] >> 2) & 0x1); *c++ = ((xmc[28] & 0x3) << 6) | ((xmc[29] & 0x7) << 3) | (xmc[30] & 0x7); *c++ = ((xmc[31] & 0x7) << 5) | ((xmc[32] & 0x7) << 2) | ((xmc[33] >> 1) & 0x3); *c++ = ((xmc[33] & 0x1) << 7) | ((xmc[34] & 0x7) << 4) | ((xmc[35] & 0x7) << 1) | ((xmc[36] >> 2) & 0x1); *c++ = ((xmc[36] & 0x3) << 6) | ((xmc[37] & 0x7) << 3) | (xmc[38] & 0x7); *c++ = ((Nc[3] & 0x7F) << 1) | ((bc[3] >> 1) & 0x1); *c++ = ((bc[3] & 0x1) << 7) | ((Mc[3] & 0x3) << 5) | ((xmaxc[3] >> 1) & 0x1F); *c++ = ((xmaxc[3] & 0x1) << 7) | ((xmc[39] & 0x7) << 4) | ((xmc[40] & 0x7) << 1) | ((xmc[41] >> 2) & 0x1); *c++ = ((xmc[41] & 0x3) << 6) /* 30 */ | ((xmc[42] & 0x7) << 3) | (xmc[43] & 0x7); *c++ = ((xmc[44] & 0x7) << 5) | ((xmc[45] & 0x7) << 2) | ((xmc[46] >> 1) & 0x3); *c++ = ((xmc[46] & 0x1) << 7) | ((xmc[47] & 0x7) << 4) | ((xmc[48] & 0x7) << 1) | ((xmc[49] >> 2) & 0x1); *c++ = ((xmc[49] & 0x3) << 6) | ((xmc[50] & 0x7) << 3) | (xmc[51] & 0x7); } /* decode.c */ /* * 4.3 FIXED POINT IMPLEMENTATION OF THE RPE-LTP DECODER */ /* code.c */ void gsm_enc_Gsm_Coder ( struct gsm_state * S, word * s, /* [0..159] samples IN */ /* * The RPE-LTD coder works on a frame by frame basis. The length of * the frame is equal to 160 samples. Some computations are done * once per frame to produce at the output of the coder the * LARc[1..8] parameters which are the coded LAR coefficients and * also to realize the inverse filtering operation for the entire * frame (160 samples of signal d[0..159]). These parts produce at * the output of the coder: */ word * LARc, /* [0..7] LAR coefficients OUT */ /* * Procedure 4.2.11 to 4.2.18 are to be executed four times per * frame. That means once for each sub-segment RPE-LTP analysis of * 40 samples. These parts produce at the output of the coder: */ word * Nc, /* [0..3] LTP lag OUT */ word * bc, /* [0..3] coded LTP gain OUT */ word * Mc, /* [0..3] RPE grid selection OUT */ word * xmaxc,/* [0..3] Coded maximum amplitude OUT */ word * xMc /* [13*4] normalized RPE samples OUT */ ) { int k; word * dp = S->dp0 + 120; /* [ -120...-1 ] */ word * dpp = dp; /* [ 0...39 ] */ static word e [50] = {0}; word so[160]; gsm_enc_Gsm_Preprocess (S, s, so); gsm_enc_Gsm_LPC_Analysis (so, LARc); gsm_enc_Gsm_Short_Term_Analysis_Filter (S, LARc, so); _Pragma("loopbound min 4 max 4") for (k = 0; k <= 3; k++, xMc += 13) { gsm_enc_Gsm_Long_Term_Predictor ( so+k*40, /* d [0..39] IN */ dp, /* dp [-120..-1] IN */ e + 5, /* e [0..39] OUT */ dpp, /* dpp [0..39] OUT */ Nc++, bc++); gsm_enc_Gsm_RPE_Encoding ( e + 5, /* e ][0..39][ IN/OUT */ xmaxc++, Mc++, xMc ); /* * gsm_enc_Gsm_Update_of_reconstructed_short_time_residual_signal * ( dpp, e + 5, dp ); */ { int i; longword ltmp; _Pragma("loopbound min 40 max 40") for (i = 0; i <= 39; i++) { dp[ i ] = GSM_ADD( e[5 + i], dpp[i] ); } } dp += 40; dpp += 40; } // //(void)memcpy( (char *)S->dp0, (char *)(S->dp0 + 160), // // 120 * sizeof(*S->dp0) ); } /* rpe.c */ /* 4.2.13 .. 4.2.17 RPE ENCODING SECTION */ /* 4.2.13 */ void gsm_enc_Weighting_filter ( 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 ]; */ longword L_result; 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] */ _Pragma("loopbound min 40 max 40") 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_enc_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_result, 13 ); x[k] = ( L_result < MIN_WORD ? MIN_WORD : (L_result > MAX_WORD ? MAX_WORD : L_result )); } } /* 4.2.14 */ void gsm_enc_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. */ { /* word temp1; */ int /* m, */ i; longword L_result, L_temp; longword EM; /* xxx should be L_EM? */ word Mc; longword L_common_0_3; Mc = 0; #undef STEP #define STEP( m, i ) L_temp = SASR( 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; } /**/ /* Down-sampling by a factor 3 to get the selected xM[0..12] * RPE sequence. */ _Pragma("loopbound min 13 max 13") for (i = 0; i <= 12; i ++) xM[i] = x[Mc + 3*i]; *Mc_out = Mc; } /* 4.12.15 */ void gsm_enc_APCM_quantization_xmaxc_to_exp_mant ( word xmaxc, /* IN */ word * exp_out, /* OUT */ word * mant_out ) /* OUT */ { word exp, mant; /* Compute exponent and mantissa of the decoded version of xmaxc */ exp = 0; if (xmaxc > 15) exp = SASR(xmaxc, 3) - 1; mant = xmaxc - (exp << 3); if (mant == 0) { exp = -4; mant = 7; } else { _Pragma("loopbound min 0 max 3") while (mant <= 7) { mant = mant << 1 | 1; exp--; } mant -= 8; } *exp_out = exp; *mant_out = mant; } void gsm_enc_APCM_quantization ( word * xM, /* [0..12] IN */ word * xMc, /* [0..12] OUT */ word * mant_out, /* OUT */ word * exp_out, /* OUT */ word * xmaxc_out /* OUT */ ) { int i, itest; word xmax, xmaxc, temp, temp1, temp2; word exp, mant; /* Find the maximum absolute value xmax of xM[0..12]. */ xmax = 0; _Pragma("loopbound min 13 max 13") 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. */ exp = 0; temp = SASR( xmax, 9 ); itest = 0; _Pragma("loopbound min 6 max 6") for (i = 0; i <= 5; i++) { itest |= (temp <= 0); temp = SASR( temp, 1 ); if (itest == 0) exp++; // exp = add (exp, 1) } temp = exp + 5; //xmaxc = gsm_enc_add( SASR(xmax, temp), exp << 3 ); xmaxc = saturate( ( SASR(xmax, temp) + (exp << 3) )); /* Quantizing and coding of the xM[0..12] RPE sequence * to get the xMc[0..12] */ gsm_enc_APCM_quantization_xmaxc_to_exp_mant( xmaxc, &exp, &mant ); /* This computation uses the fact that the decoded version of xmaxc * can be calculated by using the exponent 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 exponent. 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 */ temp1 = 6 - exp; /* normalization by the exponent */ temp2 = gsm_enc_NRFAC[ mant ]; /* inverse mantissa */ _Pragma("loopbound min 13 max 13") for (i = 0; i <= 12; i++) { temp = xM[i] << temp1; temp = GSM_MULT( temp, temp2 ); temp = SASR(temp, 12); xMc[i] = temp + 4; /* see note below */ } /* NOTE: This equation is used to make all the xMc[i] positive. */ *mant_out = mant; *exp_out = exp; *xmaxc_out = xmaxc; } /* 4.2.16 */ void gsm_enc_APCM_inverse_quantization ( word * xMc, /* [0..12] IN */ word mant, word exp, 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; longword ltmp; temp1 = gsm_enc_FAC[ mant ]; /* see 4.2-15 for mant */ temp2 = gsm_enc_sub( 6, exp ); /* see 4.2-15 for exp */ temp3 = gsm_enc_asl( 1, gsm_enc_sub( temp2, 1 )); _Pragma("loopbound min 13 max 13") for (i = 13; i--;) { /* temp = gsm_enc_sub( *xMc++ << 1, 7 ); */ temp = (*xMc++ << 1) - 7; /* restore sign */ temp <<= 12; /* 16 bit signed */ temp = GSM_MULT_R( temp1, temp ); temp = GSM_ADD( temp, temp3 ); *xMp++ = gsm_enc_asr( temp, temp2 ); } } /* 4.2.17 */ void gsm_enc_RPE_grid_positioning ( word Mc, /* grid position IN */ word * xMp, /* [0..12] IN */ 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; // // TODO: rewritten Duff's device for WCET analysis! // switch (Mc) { case 3: *ep++ = 0; case 2: *ep++ = 0; case 1: *ep++ = 0; case 0: *ep++ = *xMp++; i--; } _Pragma("loopbound min 12 max 12") do { *ep++ = 0; *ep++ = 0; *ep++ = *xMp++; } while (--i); _Pragma("loopbound min 0 max 3") while (++Mc < 4) *ep++ = 0; } /* { int i = 13; // //TODO: removed for WCET analysis //_Pragma("marker outside") switch (Mc) { case 3: *ep++ = 0; case 2: _Pragma("loopbound min 13 max 13") do { *ep++ = 0; case 1: *ep++ = 0; case 0: //_Pragma("marker inside") *ep++ = *xMp++; } while (--i); } //_Pragma("flowrestriction 1*inside <= 13*outside") _Pragma("loopbound min 0 max 3") while (++Mc < 4) *ep++ = 0; } */ /* 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_enc_Gsm_Update_of_reconstructed_short_time_residual_signal P3((dpp, ep, dp), 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_enc_add( ep[k], dpp[k] ); } #endif /* Has been inlined in code.c */ void gsm_enc_Gsm_RPE_Encoding ( 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, exp; gsm_enc_Weighting_filter(e, x); gsm_enc_RPE_grid_selection(x, xM, Mc); gsm_enc_APCM_quantization( xM, xMc, &mant, &exp, xmaxc); gsm_enc_APCM_inverse_quantization( xMc, mant, exp, xMp); gsm_enc_RPE_grid_positioning( *Mc, xMp, e ); } /* long_term.c */ #ifdef USE_TABLE_MUL unsigned int umul_table[ 513 ][ 256 ]; # define umul(x9, x15) \ ((int)(umul_table[x9][x15 & 0x0FF] + (umul_table[x9][ x15 >> 8 ] << 8))) # define table_mul(a, b) \ ( (a < 0) ? ((b < 0) ? umul(-a, -b) : -umul(-a, b)) \ : ((b < 0) ? -umul(a, -b) : umul(a, b))) #endif /* USE_TABLE_MUL */ /* * 4.2.11 .. 4.2.12 LONG TERM PREDICTOR (LTP) SECTION */ /* * This procedure 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. */ /* This procedure exists in four versions. First, the two integer * versions with or without table-multiplication (as one function); * then, the two floating point versions (as another function), with * or without scaling. */ #ifndef USE_FLOAT_MUL void gsm_enc_Calculation_of_the_LTP_parameters ( word * d, /* [0..39] IN */ word * dp, /* [-120..-1] IN */ word * bc_out, /* OUT */ word * Nc_out /* OUT */ ) { int k, lambda; word Nc, bc; word wt[40]; longword L_max, L_power; word R, S, dmax, scal; word temp; /* Search of the optimum scaling of d[0..39]. */ dmax = 0; _Pragma("loopbound min 40 max 40") for (k = 0; k <= 39; k++) { temp = d[k]; temp = GSM_ABS( temp ); if (temp > dmax) dmax = temp; } temp = 0; if (dmax != 0) temp = gsm_enc_norm( (longword)dmax << 16 ); if (temp > 6) scal = 0; else scal = 6 - temp; /* Initialization of a working array wt */ _Pragma("loopbound min 40 max 40") 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 */ _Pragma("loopbound min 81 max 81") for (lambda = 40; lambda <= 120; lambda++) { # undef STEP # ifdef USE_TABLE_MUL # define STEP(k) (table_mul(wt[k], dp[k - lambda])) # else # define STEP(k) (wt[k] * dp[k - lambda]) # endif 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 */ L_max = L_max >> (6 - scal); /* sub(6, scal) */ /* Compute the power of the reconstructed short term residual * signal dp[..] */ L_power = 0; _Pragma("loopbound min 40 max 40") for (k = 0; k <= 39; k++) { 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_enc_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. */ _Pragma("loopbound min 3 max 3") for (bc = 0; bc <= 2; bc++) /* Replaced by macro function. */ //if (R <= gsm_enc_mult(S, gsm_enc_DLB[bc])) if (R <= GSM_MULT(S, gsm_enc_DLB[bc])) break; *bc_out = bc; } #else /* USE_FLOAT_MUL */ void gsm_enc_Calculation_of_the_LTP_parameters ( word * d, /* [0..39] IN */ word * dp, /* [-120..-1] IN */ word * bc_out, /* OUT */ word * Nc_out /* OUT */ ) { 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; 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 { temp = gsm_enc_norm( (longword)dmax << 16 ); } if (temp > 6) scal = 0; else scal = 6 - temp; /* 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. */ float *lp = dp_float - lambda; float W; 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]; float E; 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 */ L_max = L_max >> (6 - scal); /* sub(6, scal) */ /* Compute the power of the reconstructed short term residual * signal dp[..] */ L_power = 0; for (k = 0; k <= 39; k++) { 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_enc_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. */ // Replaced by macro function. //for (bc = 0; bc <= 2; bc++) if (R <= gsm_enc_mult(S, gsm_enc_DLB[bc])) break; for (bc = 0; bc <= 2; bc++) if (R <= GSM_MULT(S, gsm_enc_DLB[bc])) break; *bc_out = bc; } #endif /* USE_FLOAT_MUL */ /* 4.2.12 */ void gsm_enc_Long_term_analysis_filtering ( word bc, /* IN */ word Nc, /* IN */ word * dp, /* previous d [-120..-1] IN */ word * d, /* d [0..39] IN */ word * dpp, /* estimate [0..39] OUT */ 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. */ { int k; longword ltmp; # undef STEP # define STEP(BP) \ _Pragma("loopbound min 40 max 40") \ 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_enc_Gsm_Long_Term_Predictor ( 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 */ ) { gsm_enc_Calculation_of_the_LTP_parameters( d, dp, bc, Nc ); gsm_enc_Long_term_analysis_filtering( *bc, *Nc, dp, d, dpp, e ); } /* short_term.c */ /* * SHORT TERM ANALYSIS FILTERING SECTION */ /* 4.2.8 */ void gsm_enc_Decoding_of_the_coded_Log_Area_Ratios ( word * LARc, /* coded log area ratio [0..7] IN */ word * LARpp) /* out: decoded .. */ { word temp1 /* , temp2 */; 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] */ #undef STEP #define STEP( B, MIC, INVA ) \ temp1 = GSM_ADD( *LARc++, MIC ) << 10; \ temp1 = GSM_SUB( temp1, (B >= 0 ? B << 1 : -((-B) << 1))); \ temp1 = GSM_MULT_R( INVA, temp1 ); \ *LARpp++ = GSM_ADD( temp1, temp1 ); STEP( 0, -32, 13107 ); STEP( 0, -32, 13107 ); STEP( 2048, -16, 13107 ); STEP( -2560, -16, 13107 ); STEP( 94, -8, 19223 ); STEP( -1792, -8, 17476 ); STEP( -341, -4, 31454 ); STEP( -1144, -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.) */ void gsm_enc_Coefficients_0_12 ( word * LARpp_j_1, word * LARpp_j, word * LARp) { int i; longword ltmp; _Pragma("loopbound min 8 max 8") 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)); } } void gsm_enc_Coefficients_13_26 ( word * LARpp_j_1, word * LARpp_j, word * LARp) { int i; longword ltmp; _Pragma("loopbound min 8 max 8") for (i = 1; i <= 8; i++, LARpp_j_1++, LARpp_j++, LARp++) { *LARp = GSM_ADD( SASR( *LARpp_j_1, 1), SASR( *LARpp_j, 1 )); } } void gsm_enc_Coefficients_27_39 ( word * LARpp_j_1, word * LARpp_j, word * LARp) { int i; longword ltmp; _Pragma("loopbound min 8 max 8") 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 )); } } void gsm_enc_Coefficients_40_159 ( word * LARpp_j, word * LARp) { int i; _Pragma("loopbound min 8 max 8") for (i = 1; i <= 8; i++, LARp++, LARpp_j++) { *LARp = *LARpp_j; } } /* 4.2.9.2 */ void gsm_enc_LARp_to_rp ( 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. */ { int i; word temp; longword ltmp; _Pragma("loopbound min 8 max 8") 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 */ void gsm_enc_Short_term_analysis_filtering ( struct gsm_state * S, word * rp, /* [0..7] IN */ int k_n, /* k_end - k_start */ 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. */ { word * u = S->u; int i; word di, zzz, ui, sav, rpi; longword ltmp; int j; _Pragma("loopbound min 13 max 120") for (j=0; jLARpp[ S->j ]; word * LARpp_j_1 = S->LARpp[ S->j ^= 1 ]; word LARp[8]; #undef FILTER # define FILTER gsm_enc_Short_term_analysis_filtering gsm_enc_Decoding_of_the_coded_Log_Area_Ratios( LARc, LARpp_j ); gsm_enc_Coefficients_0_12( LARpp_j_1, LARpp_j, LARp ); gsm_enc_LARp_to_rp( LARp ); FILTER( S, LARp, 13, s); gsm_enc_Coefficients_13_26( LARpp_j_1, LARpp_j, LARp); gsm_enc_LARp_to_rp( LARp ); FILTER( S, LARp, 14, s + 13); gsm_enc_Coefficients_27_39( LARpp_j_1, LARpp_j, LARp); gsm_enc_LARp_to_rp( LARp ); FILTER( S, LARp, 13, s + 27); gsm_enc_Coefficients_40_159( LARpp_j, LARp); gsm_enc_LARp_to_rp( LARp ); FILTER( S, LARp, 120, s + 40); } /* lpc.c */ #undef P /* * 4.2.4 .. 4.2.7 LPC ANALYSIS SECTION */ /* 4.2.4 */ void gsm_enc_Autocorrelation ( word * s, /* [0..159] IN/OUT */ longword * L_ACF) /* [0..8] OUT */ /* * The goal is to compute the array L_ACF[k]. The signal s[i] must * be scaled in order to avoid an overflow situation. */ { int k, i; word temp, smax, scalauto; /* Dynamic scaling of the array s[0..159] */ /* Search for the maximum. */ smax = 0; _Pragma("loopbound min 160 max 160") for (k = 0; k <= 159; k++) { temp = GSM_ABS( s[k] ); if (temp > smax) smax = temp; } /* Computation of the scaling factor. */ if (smax == 0) scalauto = 0; else { scalauto = 4 - gsm_enc_norm( (longword)smax << 16 );/* sub(4,..) */ } /* Scaling of the array s[0...159] */ if (scalauto > 0) { # define SCALE(n) \ case n: \ _Pragma("loopbound min 160 max 160") \ for (k = 0; k <= 159; k++) \ s[k] = GSM_MULT_R( s[k], 16384 >> (n-1) );\ break; switch (scalauto) { SCALE(1) SCALE(2) SCALE(3) SCALE(4) } # undef SCALE } /* Compute the L_ACF[..]. */ { word * sp = s; word sl = *sp; #undef STEP # define STEP(k) L_ACF[k] += ((longword)sl * sp[ -(k) ]); # define NEXTI sl = *++sp _Pragma("loopbound min 9 max 9") for (k = 9; k--; L_ACF[k] = 0) ; STEP (0); NEXTI; STEP(0); STEP(1); NEXTI; STEP(0); STEP(1); STEP(2); NEXTI; STEP(0); STEP(1); STEP(2); STEP(3); NEXTI; STEP(0); STEP(1); STEP(2); STEP(3); STEP(4); NEXTI; STEP(0); STEP(1); STEP(2); STEP(3); STEP(4); STEP(5); NEXTI; STEP(0); STEP(1); STEP(2); STEP(3); STEP(4); STEP(5); STEP(6); NEXTI; STEP(0); STEP(1); STEP(2); STEP(3); STEP(4); STEP(5); STEP(6); STEP(7); _Pragma("loopbound min 152 max 152") for (i = 8; i <= 159; i++) { NEXTI; STEP(0); STEP(1); STEP(2); STEP(3); STEP(4); STEP(5); STEP(6); STEP(7); STEP(8); } _Pragma("loopbound min 9 max 9") for (k = 9; k--; L_ACF[k] <<= 1) ; } /* Rescaling of the array s[0..159] */ if (scalauto > 0) { _Pragma("loopbound min 160 max 160") for (k = 160; k--; *s++ <<= scalauto) ; } } /* 4.2.5 */ void gsm_enc_Reflection_coefficients ( longword * L_ACF, /* 0...8 IN */ word * r /* 0...7 OUT */ ) { int i, m, n; word temp; longword ltmp; word ACF[9]; /* 0..8 */ word P[ 9]; /* 0..8 */ word K[ 9]; /* 2..8 */ /* Schur recursion with 16 bits arithmetic. */ if (L_ACF[0] == 0) { _Pragma("loopbound min 8 max 8") for (i = 8; i--; *r++ = 0) ; return; } temp = gsm_enc_norm( L_ACF[0] ); /* ? overflow ? */ _Pragma("loopbound min 9 max 9") for (i = 0; i <= 8; i++) ACF[i] = SASR( L_ACF[i] << temp, 16 ); /* Initialize array P[..] and K[..] for the recursion. */ _Pragma("loopbound min 7 max 7") for (i = 1; i <= 7; i++) K[ i ] = ACF[ i ]; _Pragma("loopbound min 9 max 9") for (i = 0; i <= 8; i++) P[ i ] = ACF[ i ]; /* Compute reflection coefficients */ _Pragma("loopbound min 8 max 8") for (n = 1; n <= 8; n++, r++) { temp = P[1]; temp = GSM_ABS(temp); if (P[0] < temp) { _Pragma("loopbound min 8 max 8") for (i = n; i <= 8; i++) *r++ = 0; return; } *r = gsm_enc_div( temp, P[0] ); if (P[1] > 0) *r = -*r; /* r[n] = sub(0, r[n]) */ if (n == 8) return; /* Schur recursion */ temp = GSM_MULT_R( P[1], *r ); P[0] = GSM_ADD( P[0], temp ); _Pragma("loopbound min 1 max 7") for (m = 1; m <= 8 - n; ++m) { temp = GSM_MULT_R( K[ m ], *r ); P[m] = GSM_ADD( P[ m+1 ], temp ); temp = GSM_MULT_R( P[ m+1 ], *r ); K[m] = GSM_ADD( K[ m ], temp ); } } } /* 4.2.6 */ void gsm_enc_Transformation_to_Log_Area_Ratios ( word * r /* 0..7 IN/OUT */ ) /* * The following scaling for r[..] and LAR[..] has been used: * * r[..] = integer( real_r[..]*32768. ); -1 <= real_r < 1. * LAR[..] = integer( real_LAR[..] * 16384 ); * with -1.625 <= real_LAR <= 1.625 */ { word temp; int i; /* Computation of the LAR[0..7] from the r[0..7] */ _Pragma("loopbound min 8 max 8") for (i = 1; i <= 8; i++, r++) { temp = *r; temp = GSM_ABS(temp); if (temp < 22118) { temp >>= 1; } else if (temp < 31130) { temp -= 11059; } else { temp -= 26112; temp <<= 2; } *r = *r < 0 ? -temp : temp; } } /* 4.2.7 */ void gsm_enc_Quantization_and_coding ( word * LAR /* [0..7] IN/OUT */ ) { word temp; longword ltmp; /* This procedure needs four tables; the following equations * give the optimum scaling for the constants: * * A[0..7] = integer( real_A[0..7] * 1024 ) * B[0..7] = integer( real_B[0..7] * 512 ) * MAC[0..7] = maximum of the LARc[0..7] * MIC[0..7] = minimum of the LARc[0..7] */ # undef STEP # define STEP( A, B, MAC, MIC ) \ temp = GSM_MULT( A, *LAR ); \ temp = GSM_ADD( temp, B ); \ temp = GSM_ADD( temp, 256 ); \ temp = SASR( temp, 9 ); \ *LAR = temp>MAC ? MAC - MIC : (tempz1; longword L_z2 = S->L_z2; word mp = S->mp; word s1; longword L_s2; longword L_temp; word msp, lsp; word SO; longword ltmp; /* for ADD */ ulongword utmp; /* for L_ADD */ int k = 160; _Pragma("loopbound min 160 max 160") while (k--) { /* 4.2.1 Downscaling of the input signal */ SO = SASR( *s, 3 ) << 2; s++; /* 4.2.2 Offset compensation * * This part implements a high-pass filter and requires extended * arithmetic precision for the recursive part of this filter. * The input of this procedure is the array so[0...159] and the * output the array sof[ 0...159 ]. */ /* Compute the non-recursive part */ s1 = SO - z1; /* s1 = gsm_enc_sub( *so, z1 ); */ z1 = SO; /* Compute the recursive part */ L_s2 = s1; L_s2 <<= 15; /* Execution of a 31 bv 16 bits multiplication */ msp = SASR( L_z2, 15 ); lsp = L_z2-((longword)msp<<15); /* gsm_enc_L_sub(L_z2,(msp<<15)); */ L_s2 += GSM_MULT_R( lsp, 32735 ); L_temp = (longword)msp * 32735; /* GSM_L_MULT(msp,32735) >> 1;*/ L_z2 = GSM_L_ADD( L_temp, L_s2 ); /* Compute sof[k] with rounding */ L_temp = GSM_L_ADD( L_z2, 16384 ); /* 4.2.3 Preemphasis */ msp = GSM_MULT_R( mp, -28180 ); mp = SASR( L_temp, 15 ); *so++ = GSM_ADD( mp, msp ); } S->z1 = z1; S->L_z2 = L_z2; S->mp = mp; } /* gsm_enc_bench.c */ word gsm_enc_norm (longword a ) /* * the number of left shifts needed to normalize the 32 bit * variable L_var1 for positive values on the interval * * with minimum of * minimum of 1073741824 (01000000000000000000000000000000) and * maximum of 2147483647 (01111111111111111111111111111111) * * * and for negative values on the interval with * minimum of -2147483648 (-10000000000000000000000000000000) and * maximum of -1073741824 ( -1000000000000000000000000000000). * * in order to normalize the result, the following * operation must be done: L_norm_var1 = L_var1 << norm( L_var1 ); * * (That's 'ffs', only from the left, not the right..) */ { if (a < 0) { if (a <= -1073741824) return 0; a = ~a; } return a & 0xffff0000 ? ( a & 0xff000000 ? -1 + gsm_enc_bitoff[ 0xFF & (a >> 24) ] : 7 + gsm_enc_bitoff[ 0xFF & (a >> 16) ] ) : ( a & 0xff00 ? 15 + gsm_enc_bitoff[ 0xFF & (a >> 8) ] : 23 + gsm_enc_bitoff[ 0xFF & a ] ); } word gsm_enc_asl (word a, int n) { if (n >= 16) return 0; if (n <= -16) return -(a < 0); if (n < 0) return gsm_enc_asr(a, -n); return a << n; } word gsm_enc_asr (word a, int n) { if (n >= 16) return -(a < 0); if (n <= -16) return 0; if (n < 0) return a << -n; # ifdef SASR return a >> n; # else if (a >= 0) return a >> n; else return -(word)( -(uword)a >> n ); # endif } /* * (From p. 46, end of section 4.2.5) * * NOTE: The following lines gives [sic] one correct implementation * of the div(num, denum) arithmetic operation. Compute div * which is the integer division of num by denum: with denum * >= num > 0 */ word gsm_enc_div ( word num, word denum) { longword L_num = num; longword L_denum = denum; word div = 0; int k = 15; /* The parameter num sometimes becomes zero. * Although this is explicitly guarded against in 4.2.5, * we assume that the result should then be zero as well. */ if (num == 0) return 0; _Pragma("loopbound min 15 max 15") while (k--) { div <<= 1; L_num <<= 1; if (L_num >= L_denum) { L_num -= L_denum; div++; } } return div; } gsm gsm_enc_create( void ) { unsigned int i; gsm r; r = &gsm_enc_state; _Pragma("loopbound min 648 max 648") for(i=0; i < sizeof(*r); i++) ((char *)r)[i]=0; r->nrp = 40; return r; } void gsm_enc_init( void ) { gsm_enc_state_ptr = gsm_enc_create(); } int gsm_enc_return( void ) { return gsm_enc_result; } void gsm_enc_main( void ) { gsm r; unsigned i; gsm_enc_result = 0; r = gsm_enc_state_ptr; _Pragma("loopbound min 20 max 20") for (i=0; i < SAMPLES; i++) { gsm_enc_encode(r, gsm_enc_pcmdata + i * 160, gsm_enc_gsmdata + i * sizeof(gsm_frame)); } } int main( int argc, char** argv ) { SET_UP for (jobsComplete=-1; jobsComplete