1 /* ------------------------------------------------------------------ 2 * Copyright (C) 1998-2009 PacketVideo 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either 13 * express or implied. 14 * See the License for the specific language governing permissions 15 * and limitations under the License. 16 * ------------------------------------------------------------------- 17 */ 18 /**************************************************************************************** 19 Portions of this file are derived from the following 3GPP standard: 20 21 3GPP TS 26.073 22 ANSI-C code for the Adaptive Multi-Rate (AMR) speech codec 23 Available from http://www.3gpp.org 24 25 (C) 2004, 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TTA, TTC) 26 Permission to distribute, modify and use this file under the standard license 27 terms listed above has been obtained from the copyright holder. 28 ****************************************************************************************/ 29 /* 30 Pathname: ./audio/gsm-amr/c/src/pred_lt.c 31 32 ------------------------------------------------------------------------------ 33 REVISION HISTORY 34 35 Description: Updated template used to PV coding template. First attempt at 36 optimizing C code. 37 38 Description: Deleted variables listed in the Local Stores Needed/Modified 39 sections. 40 41 Description: Updated file per comments from Phase 2/3 review. 42 43 Description: Synchronized file with UMTS version 3.2.0. Updated coding 44 template. Removed unnecessary include files. 45 46 Description: Fixed typecasting issue with TI C compiler. Updated copyright 47 year. 48 49 Description: 50 (1) Removed instance of static in the const table "inter_6" 51 (2) Changed Overflow from a global to a parameter passed via a pointer. 52 (3) Made numerous small changes to bring code more in line with PV standards. 53 54 Description: For pred_ltp() 55 1. Eliminated unused include files. 56 2. Replaced array addressing by pointers 57 3. Eliminated math operations that unnecessary checked for 58 saturation 59 4. Unrolled loops to speed up processing, use decrement loops, 60 loaded into memory filter coefficient in linear order for 61 faster execution in main loop. 62 5. Eliminated call to round by proper initialization 63 64 Description: Replaced "int" and/or "char" with defined types. 65 Added proper casting (Word32) to some left shifting operations 66 67 68 Description: Changed round function name to pv_round to avoid conflict with 69 round function in C standard library. 70 71 Who: Date: 72 Description: 73 74 ------------------------------------------------------------------------------ 75 */ 76 77 /*---------------------------------------------------------------------------- 78 ; INCLUDES 79 ----------------------------------------------------------------------------*/ 80 #include "pred_lt.h" 81 #include "cnst.h" 82 83 /*---------------------------------------------------------------------------- 84 ; MACROS 85 ; Define module specific macros here 86 ----------------------------------------------------------------------------*/ 87 88 /*---------------------------------------------------------------------------- 89 ; DEFINES 90 ; Include all pre-processor statements here. Include conditional 91 ; compile variables also. 92 ----------------------------------------------------------------------------*/ 93 #define UP_SAMP_MAX 6 94 #define L_INTER10 (L_INTERPOL-1) 95 #define FIR_SIZE (UP_SAMP_MAX*L_INTER10+1) 96 97 /*---------------------------------------------------------------------------- 98 ; LOCAL FUNCTION DEFINITIONS 99 ; Function Prototype declaration 100 ----------------------------------------------------------------------------*/ 101 102 /*---------------------------------------------------------------------------- 103 ; LOCAL STORE/BUFFER/POINTER DEFINITIONS 104 ; Variable declaration - defined here and used outside this module 105 ----------------------------------------------------------------------------*/ 106 107 /* 1/6 resolution interpolation filter (-3 dB at 3600 Hz) */ 108 /* Note: the 1/3 resolution filter is simply a subsampled 109 * version of the 1/6 resolution filter, i.e. it uses 110 * every second coefficient: 111 * 112 * inter_3l[k] = inter_6[2*k], 0 <= k <= 3*L_INTER10 113 */ 114 115 const Word16 inter_6_pred_lt[FIR_SIZE] = 116 { 117 29443, 118 28346, 25207, 20449, 14701, 8693, 3143, 119 -1352, -4402, -5865, -5850, -4673, -2783, 120 -672, 1211, 2536, 3130, 2991, 2259, 121 1170, 0, -1001, -1652, -1868, -1666, 122 -1147, -464, 218, 756, 1060, 1099, 123 904, 550, 135, -245, -514, -634, 124 -602, -451, -231, 0, 191, 308, 125 340, 296, 198, 78, -36, -120, 126 -163, -165, -132, -79, -19, 34, 127 73, 91, 89, 70, 38, 0 128 }; 129 130 131 /* 132 ------------------------------------------------------------------------------ 133 FUNCTION NAME: Pred_lt_3or6 134 ------------------------------------------------------------------------------ 135 INPUT AND OUTPUT DEFINITIONS 136 137 Inputs: 138 exc = buffer containing the excitation (Word16) 139 T0 = integer pitch lag (Word16) 140 frac = fraction of lag (Word16) 141 L_subfr = number of samples per subframe (Word16) 142 flag3 = flag to indicate the upsampling rate; if set, upsampling 143 rate is 3, otherwise, upsampling rate is 6 (Word16) 144 145 pOverflow = pointer to overflow (Flag) 146 147 Returns: 148 None 149 150 Outputs: 151 exc buffer contains the newly formed adaptive codebook excitation 152 pOverflow -> 1 if the add operation resulted in overflow 153 154 Global Variables Used: 155 inter_6_pred_lt = (1/6) resolution interpolation filter table (Word16) 156 157 Local Variables Needed: 158 None 159 160 ------------------------------------------------------------------------------ 161 FUNCTION DESCRIPTION 162 163 This function computes the result of long term prediction with fractional 164 interpolation of resolution 1/3 or 1/6. (Interpolated past excitation). 165 166 The past excitation signal at the given delay is interpolated at 167 the given fraction to build the adaptive codebook excitation. 168 On return exc[0..L_subfr-1] contains the interpolated signal 169 (adaptive codebook excitation). 170 171 ------------------------------------------------------------------------------ 172 REQUIREMENTS 173 174 None 175 176 ------------------------------------------------------------------------------ 177 REFERENCES 178 179 pred_lt.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001 180 181 ------------------------------------------------------------------------------ 182 PSEUDO-CODE 183 184 void Pred_lt_3or6 ( 185 Word16 exc[], // in/out: excitation buffer 186 Word16 T0, // input : integer pitch lag 187 Word16 frac, // input : fraction of lag 188 Word16 L_subfr, // input : subframe size 189 Word16 flag3 // input : if set, upsampling rate = 3 (6 otherwise) 190 ) 191 { 192 Word16 i, j, k; 193 Word16 *pX0, *pX1, *pX2; 194 const Word16 *pC1, *pC2; 195 Word32 s; 196 197 pX0 = &exc[-T0]; 198 199 frac = negate (frac); 200 if (flag3 != 0) 201 { 202 frac = shl (frac, 1); // inter_3l[k] = inter_6[2*k] -> k' = 2*k 203 } 204 205 if (frac < 0) 206 { 207 frac = add (frac, UP_SAMP_MAX); 208 pX0--; 209 } 210 211 for (j = 0; j < L_subfr; j++) 212 { 213 pX1 = pX0++; 214 pX2 = pX0; 215 pC1 = &inter_6[frac]; 216 pC2 = &inter_6[sub (UP_SAMP_MAX, frac)]; 217 218 s = 0; 219 for (i = 0, k = 0; i < L_INTER10; i++, k += UP_SAMP_MAX) 220 { 221 s = L_mac (s, pX1[-i], pC1[k]); 222 s = L_mac (s, pX2[i], pC2[k]); 223 } 224 225 exc[j] = pv_round (s); 226 } 227 228 return; 229 } 230 231 ------------------------------------------------------------------------------ 232 RESOURCES USED [optional] 233 234 When the code is written for a specific target processor the 235 the resources used should be documented below. 236 237 HEAP MEMORY USED: x bytes 238 239 STACK MEMORY USED: x bytes 240 241 CLOCK CYCLES: (cycle count equation for this function) + (variable 242 used to represent cycle count for each subroutine 243 called) 244 where: (cycle count variable) = cycle count for [subroutine 245 name] 246 247 ------------------------------------------------------------------------------ 248 CAUTION [optional] 249 [State any special notes, constraints or cautions for users of this function] 250 251 ------------------------------------------------------------------------------ 252 */ 253 254 void Pred_lt_3or6( 255 Word16 exc[], /* in/out: excitation buffer */ 256 Word16 T0, /* input : integer pitch lag */ 257 Word16 frac, /* input : fraction of lag */ 258 Word16 L_subfr, /* input : subframe size */ 259 Word16 flag3, /* input : if set, upsampling rate = 3 (6 otherwise) */ 260 Flag *pOverflow /* output: if set, overflow occurred in this function */ 261 ) 262 { 263 register Word16 i; 264 register Word16 j; 265 register Word16 k; 266 267 Word16 *pX0; 268 Word16 *pX2; 269 Word16 *pX3; 270 Word16 *p_exc; 271 Word16 *pC1; 272 const Word16 *pC1_ref; 273 const Word16 *pC2_ref; 274 275 Word16 Coeff_1[(L_INTER10<<1)]; 276 277 Word32 s1; 278 Word32 s2; 279 OSCL_UNUSED_ARG(pOverflow); 280 281 pX0 = &(exc[-T0]); 282 283 /* frac goes between -3 and 3 */ 284 285 frac = -frac; 286 287 if (flag3 != 0) 288 { 289 frac <<= 1; /* inter_3l[k] = inter_6[2*k] -> k' = 2*k */ 290 } 291 292 if (frac < 0) 293 { 294 frac += UP_SAMP_MAX; 295 pX0--; 296 } 297 298 pC1_ref = &inter_6_pred_lt[frac]; 299 pC2_ref = &inter_6_pred_lt[UP_SAMP_MAX-frac]; 300 301 302 pC1 = Coeff_1; 303 304 k = 0; 305 306 for (i = L_INTER10 >> 1; i > 0; i--) 307 { 308 *(pC1++) = pC1_ref[k]; 309 *(pC1++) = pC2_ref[k]; 310 k += UP_SAMP_MAX; 311 *(pC1++) = pC1_ref[k]; 312 *(pC1++) = pC2_ref[k]; 313 k += UP_SAMP_MAX; 314 315 } 316 317 p_exc = exc; 318 319 for (j = (L_subfr >> 1); j != 0 ; j--) 320 { 321 pX0++; 322 pX2 = pX0; 323 pX3 = pX0++; 324 325 pC1 = Coeff_1; 326 327 s1 = 0x00004000L; 328 s2 = 0x00004000L; 329 330 for (i = L_INTER10 >> 1; i > 0; i--) 331 { 332 s2 += ((Word32) * (pX3--)) * *(pC1); 333 s1 += ((Word32) * (pX3)) * *(pC1++); 334 s1 += ((Word32) * (pX2++)) * *(pC1); 335 s2 += ((Word32) * (pX2)) * *(pC1++); 336 s2 += ((Word32) * (pX3--)) * *(pC1); 337 s1 += ((Word32) * (pX3)) * *(pC1++); 338 s1 += ((Word32) * (pX2++)) * *(pC1); 339 s2 += ((Word32) * (pX2)) * *(pC1++); 340 341 } /* for (i = L_INTER10>>1; i > 0; i--) */ 342 343 *(p_exc++) = (Word16)(s1 >> 15); 344 *(p_exc++) = (Word16)(s2 >> 15); 345 346 } /* for (j = (L_subfr>>1); j != 0 ; j--) */ 347 348 return; 349 } 350
