1 /* 2 * Copyright 1992 by Jutta Degener and Carsten Bormann, Technische 3 * Universitaet Berlin. See the accompanying file "COPYRIGHT" for 4 * details. THERE IS ABSOLUTELY NO WARRANTY FOR THIS SOFTWARE. 5 */ 6 7 /* $Header: /tmp_amd/presto/export/kbs/jutta/src/gsm/RCS/short_term.c,v 1.2 1994/05/10 20:18:47 jutta Exp $ */ 8 9 #include <stdio.h> 10 #include <assert.h> 11 12 #include "private.h" 13 14 #include "gsm.h" 15 #include "proto.h" 16 17 /* 18 * SHORT TERM ANALYSIS FILTERING SECTION 19 */ 20 21 /* 4.2.8 */ 22 23 static void Decoding_of_the_coded_Log_Area_Ratios P2((LARc,LARpp), 24 word * LARc, /* coded log area ratio [0..7] IN */ 25 word * LARpp) /* out: decoded .. */ 26 { 27 register word temp1 /* , temp2 */; 28 register long ltmp; /* for GSM_ADD */ 29 30 /* This procedure requires for efficient implementation 31 * two tables. 32 * 33 * INVA[1..8] = integer( (32768 * 8) / real_A[1..8]) 34 * MIC[1..8] = minimum value of the LARc[1..8] 35 */ 36 37 /* Compute the LARpp[1..8] 38 */ 39 40 /* for (i = 1; i <= 8; i++, B++, MIC++, INVA++, LARc++, LARpp++) { 41 * 42 * temp1 = GSM_ADD( *LARc, *MIC ) << 10; 43 * temp2 = *B << 1; 44 * temp1 = GSM_SUB( temp1, temp2 ); 45 * 46 * assert(*INVA != MIN_WORD); 47 * 48 * temp1 = GSM_MULT_R( *INVA, temp1 ); 49 * *LARpp = GSM_ADD( temp1, temp1 ); 50 * } 51 */ 52 53 #undef STEP 54 #define STEP( B_TIMES_TWO, MIC, INVA ) \ 55 temp1 = GSM_ADD( *LARc++, MIC ) << 10; \ 56 temp1 = GSM_SUB( temp1, B_TIMES_TWO ); \ 57 temp1 = GSM_MULT_R( INVA, temp1 ); \ 58 *LARpp++ = GSM_ADD( temp1, temp1 ); 59 60 STEP( 0, -32, 13107 ); 61 STEP( 0, -32, 13107 ); 62 STEP( 4096, -16, 13107 ); 63 STEP( -5120, -16, 13107 ); 64 65 STEP( 188, -8, 19223 ); 66 STEP( -3584, -8, 17476 ); 67 STEP( -682, -4, 31454 ); 68 STEP( -2288, -4, 29708 ); 69 70 /* NOTE: the addition of *MIC is used to restore 71 * the sign of *LARc. 72 */ 73 } 74 75 /* 4.2.9 */ 76 /* Computation of the quantized reflection coefficients 77 */ 78 79 /* 4.2.9.1 Interpolation of the LARpp[1..8] to get the LARp[1..8] 80 */ 81 82 /* 83 * Within each frame of 160 analyzed speech samples the short term 84 * analysis and synthesis filters operate with four different sets of 85 * coefficients, derived from the previous set of decoded LARs(LARpp(j-1)) 86 * and the actual set of decoded LARs (LARpp(j)) 87 * 88 * (Initial value: LARpp(j-1)[1..8] = 0.) 89 */ 90 91 static void Coefficients_0_12 P3((LARpp_j_1, LARpp_j, LARp), 92 register word * LARpp_j_1, 93 register word * LARpp_j, 94 register word * LARp) 95 { 96 register int i; 97 register longword ltmp; 98 99 for (i = 1; i <= 8; i++, LARp++, LARpp_j_1++, LARpp_j++) { 100 *LARp = GSM_ADD( SASR( *LARpp_j_1, 2 ), SASR( *LARpp_j, 2 )); 101 *LARp = GSM_ADD( *LARp, SASR( *LARpp_j_1, 1)); 102 } 103 } 104 105 static void Coefficients_13_26 P3((LARpp_j_1, LARpp_j, LARp), 106 register word * LARpp_j_1, 107 register word * LARpp_j, 108 register word * LARp) 109 { 110 register int i; 111 register longword ltmp; 112 for (i = 1; i <= 8; i++, LARpp_j_1++, LARpp_j++, LARp++) { 113 *LARp = GSM_ADD( SASR( *LARpp_j_1, 1), SASR( *LARpp_j, 1 )); 114 } 115 } 116 117 static void Coefficients_27_39 P3((LARpp_j_1, LARpp_j, LARp), 118 register word * LARpp_j_1, 119 register word * LARpp_j, 120 register word * LARp) 121 { 122 register int i; 123 register longword ltmp; 124 125 for (i = 1; i <= 8; i++, LARpp_j_1++, LARpp_j++, LARp++) { 126 *LARp = GSM_ADD( SASR( *LARpp_j_1, 2 ), SASR( *LARpp_j, 2 )); 127 *LARp = GSM_ADD( *LARp, SASR( *LARpp_j, 1 )); 128 } 129 } 130 131 132 static void Coefficients_40_159 P2((LARpp_j, LARp), 133 register word * LARpp_j, 134 register word * LARp) 135 { 136 register int i; 137 138 for (i = 1; i <= 8; i++, LARp++, LARpp_j++) 139 *LARp = *LARpp_j; 140 } 141 142 /* 4.2.9.2 */ 143 144 static void LARp_to_rp P1((LARp), 145 register word * LARp) /* [0..7] IN/OUT */ 146 /* 147 * The input of this procedure is the interpolated LARp[0..7] array. 148 * The reflection coefficients, rp[i], are used in the analysis 149 * filter and in the synthesis filter. 150 */ 151 { 152 register int i; 153 register word temp; 154 register longword ltmp; 155 156 for (i = 1; i <= 8; i++, LARp++) { 157 158 /* temp = GSM_ABS( *LARp ); 159 * 160 * if (temp < 11059) temp <<= 1; 161 * else if (temp < 20070) temp += 11059; 162 * else temp = GSM_ADD( temp >> 2, 26112 ); 163 * 164 * *LARp = *LARp < 0 ? -temp : temp; 165 */ 166 167 if (*LARp < 0) { 168 temp = *LARp == MIN_WORD ? MAX_WORD : -(*LARp); 169 *LARp = - ((temp < 11059) ? temp << 1 170 : ((temp < 20070) ? temp + 11059 171 : GSM_ADD( temp >> 2, 26112 ))); 172 } else { 173 temp = *LARp; 174 *LARp = (temp < 11059) ? temp << 1 175 : ((temp < 20070) ? temp + 11059 176 : GSM_ADD( temp >> 2, 26112 )); 177 } 178 } 179 } 180 181 182 /* 4.2.10 */ 183 static void Short_term_analysis_filtering P4((S,rp,k_n,s), 184 struct gsm_state * S, 185 register word * rp, /* [0..7] IN */ 186 register int k_n, /* k_end - k_start */ 187 register word * s /* [0..n-1] IN/OUT */ 188 ) 189 /* 190 * This procedure computes the short term residual signal d[..] to be fed 191 * to the RPE-LTP loop from the s[..] signal and from the local rp[..] 192 * array (quantized reflection coefficients). As the call of this 193 * procedure can be done in many ways (see the interpolation of the LAR 194 * coefficient), it is assumed that the computation begins with index 195 * k_start (for arrays d[..] and s[..]) and stops with index k_end 196 * (k_start and k_end are defined in 4.2.9.1). This procedure also 197 * needs to keep the array u[0..7] in memory for each call. 198 */ 199 { 200 register word * u = S->u; 201 register int i; 202 register word di, zzz, ui, sav, rpi; 203 register longword ltmp; 204 205 for (; k_n--; s++) { 206 207 di = sav = *s; 208 209 for (i = 0; i < 8; i++) { /* YYY */ 210 211 ui = u[i]; 212 rpi = rp[i]; 213 u[i] = sav; 214 215 zzz = GSM_MULT_R(rpi, di); 216 sav = GSM_ADD( ui, zzz); 217 218 zzz = GSM_MULT_R(rpi, ui); 219 di = GSM_ADD( di, zzz ); 220 } 221 222 *s = di; 223 } 224 } 225 226 #if defined(USE_FLOAT_MUL) && defined(FAST) 227 228 static void Fast_Short_term_analysis_filtering P4((S,rp,k_n,s), 229 struct gsm_state * S, 230 register word * rp, /* [0..7] IN */ 231 register int k_n, /* k_end - k_start */ 232 register word * s /* [0..n-1] IN/OUT */ 233 ) 234 { 235 register word * u = S->u; 236 register int i; 237 238 float uf[8], 239 rpf[8]; 240 241 register float scalef = 3.0517578125e-5; 242 register float sav, di, temp; 243 244 for (i = 0; i < 8; ++i) { 245 uf[i] = u[i]; 246 rpf[i] = rp[i] * scalef; 247 } 248 for (; k_n--; s++) { 249 sav = di = *s; 250 for (i = 0; i < 8; ++i) { 251 register float rpfi = rpf[i]; 252 register float ufi = uf[i]; 253 254 uf[i] = sav; 255 temp = rpfi * di + ufi; 256 di += rpfi * ufi; 257 sav = temp; 258 } 259 *s = di; 260 } 261 for (i = 0; i < 8; ++i) u[i] = uf[i]; 262 } 263 #endif /* ! (defined (USE_FLOAT_MUL) && defined (FAST)) */ 264 265 static void Short_term_synthesis_filtering P5((S,rrp,k,wt,sr), 266 struct gsm_state * S, 267 register word * rrp, /* [0..7] IN */ 268 register int k, /* k_end - k_start */ 269 register word * wt, /* [0..k-1] IN */ 270 register word * sr /* [0..k-1] OUT */ 271 ) 272 { 273 register word * v = S->v; 274 register int i; 275 register word sri, tmp1, tmp2; 276 register longword ltmp; /* for GSM_ADD & GSM_SUB */ 277 278 while (k--) { 279 sri = *wt++; 280 for (i = 8; i--;) { 281 282 /* sri = GSM_SUB( sri, gsm_mult_r( rrp[i], v[i] ) ); 283 */ 284 tmp1 = rrp[i]; 285 tmp2 = v[i]; 286 tmp2 = ( tmp1 == MIN_WORD && tmp2 == MIN_WORD 287 ? MAX_WORD 288 : 0x0FFFF & (( (longword)tmp1 * (longword)tmp2 289 + 16384) >> 15)) ; 290 291 sri = GSM_SUB( sri, tmp2 ); 292 293 /* v[i+1] = GSM_ADD( v[i], gsm_mult_r( rrp[i], sri ) ); 294 */ 295 tmp1 = ( tmp1 == MIN_WORD && sri == MIN_WORD 296 ? MAX_WORD 297 : 0x0FFFF & (( (longword)tmp1 * (longword)sri 298 + 16384) >> 15)) ; 299 300 v[i+1] = GSM_ADD( v[i], tmp1); 301 } 302 *sr++ = v[0] = sri; 303 } 304 } 305 306 307 #if defined(FAST) && defined(USE_FLOAT_MUL) 308 309 static void Fast_Short_term_synthesis_filtering P5((S,rrp,k,wt,sr), 310 struct gsm_state * S, 311 register word * rrp, /* [0..7] IN */ 312 register int k, /* k_end - k_start */ 313 register word * wt, /* [0..k-1] IN */ 314 register word * sr /* [0..k-1] OUT */ 315 ) 316 { 317 register word * v = S->v; 318 register int i; 319 320 float va[9], rrpa[8]; 321 register float scalef = 3.0517578125e-5, temp; 322 323 for (i = 0; i < 8; ++i) { 324 va[i] = v[i]; 325 rrpa[i] = (float)rrp[i] * scalef; 326 } 327 while (k--) { 328 register float sri = *wt++; 329 for (i = 8; i--;) { 330 sri -= rrpa[i] * va[i]; 331 if (sri < -32768.) sri = -32768.; 332 else if (sri > 32767.) sri = 32767.; 333 334 temp = va[i] + rrpa[i] * sri; 335 if (temp < -32768.) temp = -32768.; 336 else if (temp > 32767.) temp = 32767.; 337 va[i+1] = temp; 338 } 339 *sr++ = va[0] = sri; 340 } 341 for (i = 0; i < 9; ++i) v[i] = va[i]; 342 } 343 344 #endif /* defined(FAST) && defined(USE_FLOAT_MUL) */ 345 346 void Gsm_Short_Term_Analysis_Filter P3((S,LARc,s), 347 348 struct gsm_state * S, 349 350 word * LARc, /* coded log area ratio [0..7] IN */ 351 word * s /* signal [0..159] IN/OUT */ 352 ) 353 { 354 word * LARpp_j = S->LARpp[ S->j ]; 355 word * LARpp_j_1 = S->LARpp[ S->j ^= 1 ]; 356 357 word LARp[8]; 358 359 #undef FILTER 360 #if defined(FAST) && defined(USE_FLOAT_MUL) 361 # define FILTER (* (S->fast \ 362 ? Fast_Short_term_analysis_filtering \ 363 : Short_term_analysis_filtering )) 364 365 #else 366 # define FILTER Short_term_analysis_filtering 367 #endif 368 369 Decoding_of_the_coded_Log_Area_Ratios( LARc, LARpp_j ); 370 371 Coefficients_0_12( LARpp_j_1, LARpp_j, LARp ); 372 LARp_to_rp( LARp ); 373 FILTER( S, LARp, 13, s); 374 375 Coefficients_13_26( LARpp_j_1, LARpp_j, LARp); 376 LARp_to_rp( LARp ); 377 FILTER( S, LARp, 14, s + 13); 378 379 Coefficients_27_39( LARpp_j_1, LARpp_j, LARp); 380 LARp_to_rp( LARp ); 381 FILTER( S, LARp, 13, s + 27); 382 383 Coefficients_40_159( LARpp_j, LARp); 384 LARp_to_rp( LARp ); 385 FILTER( S, LARp, 120, s + 40); 386 } 387 388 void Gsm_Short_Term_Synthesis_Filter P4((S, LARcr, wt, s), 389 struct gsm_state * S, 390 391 word * LARcr, /* received log area ratios [0..7] IN */ 392 word * wt, /* received d [0..159] IN */ 393 394 word * s /* signal s [0..159] OUT */ 395 ) 396 { 397 word * LARpp_j = S->LARpp[ S->j ]; 398 word * LARpp_j_1 = S->LARpp[ S->j ^=1 ]; 399 400 word LARp[8]; 401 402 #undef FILTER 403 #if defined(FAST) && defined(USE_FLOAT_MUL) 404 405 # define FILTER (* (S->fast \ 406 ? Fast_Short_term_synthesis_filtering \ 407 : Short_term_synthesis_filtering )) 408 #else 409 # define FILTER Short_term_synthesis_filtering 410 #endif 411 412 Decoding_of_the_coded_Log_Area_Ratios( LARcr, LARpp_j ); 413 414 Coefficients_0_12( LARpp_j_1, LARpp_j, LARp ); 415 LARp_to_rp( LARp ); 416 FILTER( S, LARp, 13, wt, s ); 417 418 Coefficients_13_26( LARpp_j_1, LARpp_j, LARp); 419 LARp_to_rp( LARp ); 420 FILTER( S, LARp, 14, wt + 13, s + 13 ); 421 422 Coefficients_27_39( LARpp_j_1, LARpp_j, LARp); 423 LARp_to_rp( LARp ); 424 FILTER( S, LARp, 13, wt + 27, s + 27 ); 425 426 Coefficients_40_159( LARpp_j, LARp ); 427 LARp_to_rp( LARp ); 428 FILTER(S, LARp, 120, wt + 40, s + 40); 429 } 430
