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 ------------------------------------------------------------------------------ 20 21 PacketVideo Corp. 22 MP3 Decoder Library 23 24 Filename: pvmp3_dequantize_sample.cpp 25 26 Functions: 27 power_1_third 28 pvmp3_dequantize_sample 29 30 Date: 09/21/2007 31 32 ------------------------------------------------------------------------------ 33 REVISION HISTORY 34 35 36 Description: 37 38 ------------------------------------------------------------------------------ 39 INPUT AND OUTPUT DEFINITIONS 40 41 power_1_third 42 int32 power_1_third( int32 xx) 43 44 Input 45 int32 xx, int32 in the [0, 8192] range 46 47 Returns 48 49 int32 xx^(1/3) int32 Q26 number representing 50 the 1/3 power of the input 51 52 ------------------------------------------------------------------------------ 53 INPUT AND OUTPUT DEFINITIONS 54 55 pvmp3_dequantize_sample 56 57 Input 58 int32 is[SUBBANDS_NUMBER*FILTERBANK_BANDS], 59 mp3ScaleFactors *scalefac, scale factor structure 60 struct gr_info_s *gr_info, granule structure informatiom 61 mp3Header *info mp3 header info 62 63 Returns 64 65 int32 is[SUBBANDS_NUMBER*FILTERBANK_BANDS], dequantize output as (.)^(4/3) 66 67 ------------------------------------------------------------------------------ 68 FUNCTION DESCRIPTION 69 70 dequantize sample 71 72 ------------------------------------------------------------------------------ 73 REQUIREMENTS 74 75 76 ------------------------------------------------------------------------------ 77 REFERENCES 78 79 [1] ISO MPEG Audio Subgroup Software Simulation Group (1996) 80 ISO 13818-3 MPEG-2 Audio Decoder - Lower Sampling Frequency Extension 81 82 ------------------------------------------------------------------------------ 83 PSEUDO-CODE 84 85 ------------------------------------------------------------------------------ 86 */ 87 88 89 /*---------------------------------------------------------------------------- 90 ; INCLUDES 91 ----------------------------------------------------------------------------*/ 92 93 #include "pv_mp3dec_fxd_op.h" 94 #include "pvmp3_dec_defs.h" 95 #include "pvmp3_dequantize_sample.h" 96 #include "pvmp3_normalize.h" 97 #include "mp3_mem_funcs.h" 98 #include "pvmp3_tables.h" 99 100 /*---------------------------------------------------------------------------- 101 ; MACROS 102 ; Define module specific macros here 103 ----------------------------------------------------------------------------*/ 104 105 106 /*---------------------------------------------------------------------------- 107 ; DEFINES 108 ; Include all pre-processor statements here. Include conditional 109 ; compile variables also. 110 ----------------------------------------------------------------------------*/ 111 #define Q30_fmt(a)(int32(double(0x40000000)*a)) 112 #define Q29_fmt(a)(int32(double(0x20000000)*a)) 113 114 /*---------------------------------------------------------------------------- 115 ; LOCAL FUNCTION DEFINITIONS 116 ; Function Prototype declaration 117 ----------------------------------------------------------------------------*/ 118 119 /*---------------------------------------------------------------------------- 120 ; LOCAL STORE/BUFFER/POINTER DEFINITIONS 121 ; Variable declaration - defined here and used outside this module 122 ----------------------------------------------------------------------------*/ 123 const int32 pretab[22] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 3, 3, 3, 2, 0}; 124 125 const int32 pow_2_1_fourth[4] = 126 { 127 Q30_fmt(1.0), Q30_fmt(1.18920711500272), 128 Q30_fmt(1.41421356237310), Q30_fmt(1.68179283050743) 129 }; 130 131 const int32 two_cubic_roots[7] = 132 { 133 Q29_fmt(0), Q29_fmt(1.25992104989487), 134 Q29_fmt(1.58740105196820), Q29_fmt(2.00000000000000), 135 Q29_fmt(2.51984209978975), Q29_fmt(3.17480210393640), 136 Q29_fmt(3.99999999999999) 137 }; 138 139 /*---------------------------------------------------------------------------- 140 ; EXTERNAL FUNCTION REFERENCES 141 ; Declare functions defined elsewhere and referenced in this module 142 ----------------------------------------------------------------------------*/ 143 144 /*---------------------------------------------------------------------------- 145 ; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES 146 ; Declare variables used in this module but defined elsewhere 147 ----------------------------------------------------------------------------*/ 148 149 /*---------------------------------------------------------------------------- 150 ; FUNCTION CODE 151 ----------------------------------------------------------------------------*/ 152 153 154 int32 power_1_third(int32 xx) 155 { 156 157 if (xx <= 512) 158 { 159 return (power_one_third[xx] >> 1); 160 } 161 else 162 { 163 if (xx >> 15) 164 { 165 return 0x7FFFFFFF; /* saturate any value over 32767 */ 166 } 167 else 168 { 169 int32 x = xx; 170 int32 m = 22 - pvmp3_normalize(xx); 171 172 xx >>= m; 173 xx = (power_one_third[xx]) + (((power_one_third[xx+1] - power_one_third[xx]) >> m) * (x & ((1 << m) - 1))); 174 return (fxp_mul32_Q30(xx, two_cubic_roots[m])); 175 } 176 177 } 178 } 179 180 181 /*---------------------------------------------------------------------------- 182 ; FUNCTION CODE 183 ----------------------------------------------------------------------------*/ 184 185 186 187 void pvmp3_dequantize_sample(int32 is[SUBBANDS_NUMBER*FILTERBANK_BANDS], 188 mp3ScaleFactors *scalefac, 189 granuleInfo *gr_info, 190 int32 used_freq_lines, 191 mp3Header *info) 192 { 193 int32 ss; 194 int32 cb = 0; 195 int32 global_gain; 196 int32 sfreq = info->sampling_frequency + info->version_x + (info->version_x << 1); 197 198 /* apply formula per block type */ 199 200 if (gr_info->window_switching_flag && (gr_info->block_type == 2)) 201 { 202 int32 next_cb_boundary; 203 int32 cb_begin = 0; 204 int32 cb_width = 0; 205 int32 mixstart = 8; /* added 2003/08/21 efs */ 206 207 if (info->version_x != MPEG_1) 208 { 209 mixstart = 6; /* different value in MPEG2 LSF */ 210 } 211 212 if (gr_info->mixed_block_flag) 213 { 214 next_cb_boundary = mp3_sfBandIndex[sfreq].l[1]; /* LONG blocks: 0,1,3 */ 215 } 216 else 217 { 218 next_cb_boundary = mp3_sfBandIndex[sfreq].s[1] * 3; /* pure SHORT block */ 219 cb_width = 0; 220 } 221 222 global_gain = gr_info->global_gain; 223 int32 two_raise_one_fourth = pow_2_1_fourth[global_gain&0x3]; 224 global_gain = 12 + (global_gain >> 2); 225 226 for (ss = 0 ; ss < used_freq_lines ; ss++) 227 { 228 if (ss == next_cb_boundary) 229 { 230 cb++; /* critical band counter */ 231 if (gr_info->mixed_block_flag) 232 { 233 if (next_cb_boundary == mp3_sfBandIndex[sfreq].l[mixstart]) 234 { 235 next_cb_boundary = mp3_sfBandIndex[sfreq].s[4] * 3; 236 237 cb_begin = mp3_sfBandIndex[sfreq].s[3] * 3; 238 cb_width = 3; 239 cb = 3; 240 } 241 else if (ss < mp3_sfBandIndex[sfreq].l[mixstart]) 242 { 243 next_cb_boundary = mp3_sfBandIndex[sfreq].l[cb+1]; 244 } 245 else 246 { 247 next_cb_boundary = mp3_sfBandIndex[sfreq].s[cb+1] * 3; 248 249 cb_width = cb; 250 cb_begin = mp3_sfBandIndex[sfreq].s[cb] * 3; 251 } 252 253 if (ss < 2*FILTERBANK_BANDS) 254 { /* 1st 2 subbands of switched blocks */ 255 global_gain = (gr_info->global_gain); 256 global_gain -= (1 + gr_info->scalefac_scale) * 257 (scalefac->l[cb] + gr_info->preflag * pretab[cb]) << 1; 258 259 two_raise_one_fourth = pow_2_1_fourth[global_gain&0x3]; 260 global_gain = 12 + (global_gain >> 2); 261 } 262 } 263 else 264 { 265 next_cb_boundary = mp3_sfBandIndex[sfreq].s[cb+1] * 3; 266 cb_width = cb; 267 cb_begin = mp3_sfBandIndex[sfreq].s[cb] * 3; 268 } 269 270 } /* end-if ( ss == next_cb_boundary) */ 271 272 /* Do long/short dependent scaling operations. */ 273 if ((gr_info->mixed_block_flag == 0) || (gr_info->mixed_block_flag && (ss >= 2*FILTERBANK_BANDS))) 274 { 275 int32 temp2 = fxp_mul32_Q32((ss - cb_begin) << 16, mp3_shortwindBandWidths[sfreq][cb_width]); 276 temp2 = (temp2 + 1) >> 15; 277 278 global_gain = (gr_info->global_gain); 279 global_gain -= gr_info->subblock_gain[temp2] << 3; 280 global_gain -= (1 + gr_info->scalefac_scale) * (scalefac->s[temp2][cb] << 1); 281 282 two_raise_one_fourth = pow_2_1_fourth[global_gain&0x3]; 283 global_gain = 12 + (global_gain >> 2); 284 285 } 286 287 288 /* 289 * xr[sb][ss] = 2^(global_gain/4) 290 */ 291 292 /* Scale quantized value. */ 293 294 /* 0 < abs(is[ss]) < 8192 */ 295 296 int32 tmp = fxp_mul32_Q30((is[ss] << 16), power_1_third(pv_abs(is[ ss]))); 297 298 tmp = fxp_mul32_Q30(tmp, two_raise_one_fourth); 299 300 if (global_gain < 0) 301 { 302 int32 temp = - global_gain; 303 if (temp < 32) 304 { 305 is[ss] = (tmp >> temp); 306 } 307 else 308 { 309 is[ss] = 0; 310 } 311 } 312 else 313 { 314 is[ss] = (tmp << global_gain); 315 } 316 317 } /* for (ss=0 ; ss < used_freq_lines ; ss++) */ 318 319 } 320 else 321 { 322 323 for (cb = 0 ; cb < 22 ; cb++) 324 { 325 326 /* Compute overall (global) scaling. */ 327 328 global_gain = (gr_info->global_gain); 329 330 global_gain -= (1 + gr_info->scalefac_scale) * 331 (scalefac->l[cb] + gr_info->preflag * pretab[cb]) << 1; 332 333 334 int32 two_raise_one_fourth = pow_2_1_fourth[global_gain&0x3]; 335 global_gain = 12 + (global_gain >> 2); 336 337 /* 338 * xr[sb][ss] = 2^(global_gain/4) 339 */ 340 341 /* Scale quantized value. */ 342 343 if (used_freq_lines >= mp3_sfBandIndex[sfreq].l[cb+1]) 344 { 345 if (global_gain <= 0) 346 { 347 global_gain = - global_gain; 348 if (global_gain < 32) 349 { 350 for (ss = mp3_sfBandIndex[sfreq].l[cb]; ss < mp3_sfBandIndex[sfreq].l[cb+1]; ss += 2) 351 { 352 int32 tmp = is[ss]; 353 if (tmp) 354 { 355 tmp = fxp_mul32_Q30((tmp << 16), power_1_third(pv_abs(tmp))); 356 is[ss] = fxp_mul32_Q30(tmp, two_raise_one_fourth) >> global_gain; 357 } 358 tmp = is[ss+1]; 359 if (tmp) 360 { 361 tmp = fxp_mul32_Q30((tmp << 16), power_1_third(pv_abs(tmp))); 362 is[ss+1] = fxp_mul32_Q30(tmp, two_raise_one_fourth) >> global_gain; 363 } 364 } 365 } 366 else 367 { 368 pv_memset(&is[ mp3_sfBandIndex[sfreq].l[cb]], 369 0, 370 (mp3_sfBandIndex[sfreq].l[cb+1] - mp3_sfBandIndex[sfreq].l[cb])*sizeof(*is)); 371 } 372 } 373 else 374 { 375 for (ss = mp3_sfBandIndex[sfreq].l[cb]; ss < mp3_sfBandIndex[sfreq].l[cb+1]; ss += 2) 376 { 377 int32 tmp = is[ss]; 378 if (tmp) 379 { 380 tmp = fxp_mul32_Q30((tmp << 16), power_1_third(pv_abs(tmp))); 381 is[ss] = fxp_mul32_Q30(tmp, two_raise_one_fourth) << global_gain; 382 } 383 384 tmp = is[ss+1]; 385 if (tmp) 386 { 387 tmp = fxp_mul32_Q30((tmp << 16), power_1_third(pv_abs(tmp))); 388 is[ss+1] = fxp_mul32_Q30(tmp, two_raise_one_fourth) << global_gain; 389 } 390 } 391 } 392 } 393 else 394 { 395 if (global_gain <= 0) 396 { 397 global_gain = - global_gain; 398 if (global_gain < 32) 399 { 400 for (ss = mp3_sfBandIndex[sfreq].l[cb]; ss < used_freq_lines; ss += 2) 401 { 402 int32 tmp = is[ss]; 403 if (tmp) 404 { 405 tmp = fxp_mul32_Q30((tmp << 16), power_1_third(pv_abs(tmp))); 406 is[ss] = fxp_mul32_Q30(tmp, two_raise_one_fourth) >> global_gain; 407 } 408 tmp = is[ss+1]; 409 if (tmp) 410 { 411 tmp = fxp_mul32_Q30((tmp << 16), power_1_third(pv_abs(tmp))); 412 is[ss+1] = fxp_mul32_Q30(tmp, two_raise_one_fourth) >> global_gain; 413 } 414 } 415 416 } 417 else 418 { 419 pv_memset(&is[ mp3_sfBandIndex[sfreq].l[cb]], 420 0, 421 (mp3_sfBandIndex[sfreq].l[cb+1] - mp3_sfBandIndex[sfreq].l[cb])*sizeof(*is)); 422 } 423 } 424 else 425 { 426 for (ss = mp3_sfBandIndex[sfreq].l[cb]; ss < used_freq_lines; ss++) 427 { 428 int32 tmp = is[ss]; 429 430 if (tmp) 431 { 432 tmp = fxp_mul32_Q30((tmp << 16), power_1_third(pv_abs(tmp))); 433 is[ss] = fxp_mul32_Q30(tmp, two_raise_one_fourth) << global_gain; 434 } 435 } 436 } 437 438 cb = 22; // force breaking out of the loop 439 440 } /* if ( used_freq_lines >= mp3_sfBandIndex[sfreq].l[cb+1]) */ 441 442 } /* for (cb=0 ; cb < 22 ; cb++) */ 443 444 } /* if (gr_info->window_switching_flag && (gr_info->block_type == 2)) */ 445 446 447 pv_memset(&is[used_freq_lines], 448 0, 449 (FILTERBANK_BANDS*SUBBANDS_NUMBER - used_freq_lines)*sizeof(*is)); 450 451 } 452 453
