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 INPUT AND OUTPUT DEFINITIONS 21 22 Inputs: 23 [input_variable_name] = [description of the input to module, its type 24 definition, and length (when applicable)] 25 26 Local Stores/Buffers/Pointers Needed: 27 [local_store_name] = [description of the local store, its type 28 definition, and length (when applicable)] 29 [local_buffer_name] = [description of the local buffer, its type 30 definition, and length (when applicable)] 31 [local_ptr_name] = [description of the local pointer, its type 32 definition, and length (when applicable)] 33 34 Global Stores/Buffers/Pointers Needed: 35 [global_store_name] = [description of the global store, its type 36 definition, and length (when applicable)] 37 [global_buffer_name] = [description of the global buffer, its type 38 definition, and length (when applicable)] 39 [global_ptr_name] = [description of the global pointer, its type 40 definition, and length (when applicable)] 41 42 Outputs: 43 [return_variable_name] = [description of data/pointer returned 44 by module, its type definition, and length 45 (when applicable)] 46 47 Pointers and Buffers Modified: 48 [variable_bfr_ptr] points to the [describe where the 49 variable_bfr_ptr points to, its type definition, and length 50 (when applicable)] 51 [variable_bfr] contents are [describe the new contents of 52 variable_bfr] 53 54 Local Stores Modified: 55 [local_store_name] = [describe new contents, its type 56 definition, and length (when applicable)] 57 58 Global Stores Modified: 59 [global_store_name] = [describe new contents, its type 60 definition, and length (when applicable)] 61 62 ------------------------------------------------------------------------------ 63 FUNCTION DESCRIPTION 64 65 ------------------------------------------------------------------------------ 66 REQUIREMENTS 67 68 ------------------------------------------------------------------------------ 69 REFERENCES 70 71 ------------------------------------------------------------------------------ 72 PSEUDO-CODE 73 74 ------------------------------------------------------------------------------ 75 RESOURCES USED 76 When the code is written for a specific target processor the 77 the resources used should be documented below. 78 79 STACK USAGE: [stack count for this module] + [variable to represent 80 stack usage for each subroutine called] 81 82 where: [stack usage variable] = stack usage for [subroutine 83 name] (see [filename].ext) 84 85 DATA MEMORY USED: x words 86 87 PROGRAM MEMORY USED: x words 88 89 CLOCK CYCLES: [cycle count equation for this module] + [variable 90 used to represent cycle count for each subroutine 91 called] 92 93 where: [cycle count variable] = cycle count for [subroutine 94 name] (see [filename].ext) 95 96 ------------------------------------------------------------------------------ 97 */ 98 99 /*---------------------------------------------------------------------------- 100 ; INCLUDES 101 ----------------------------------------------------------------------------*/ 102 #include "mp4dec_lib.h" 103 #include "idct.h" 104 #include "motion_comp.h" 105 106 #define OSCL_DISABLE_WARNING_CONV_POSSIBLE_LOSS_OF_DATA 107 /*---------------------------------------------------------------------------- 108 ; MACROS 109 ; Define module specific macros here 110 ----------------------------------------------------------------------------*/ 111 112 /*---------------------------------------------------------------------------- 113 ; DEFINES 114 ; Include all pre-processor statements here. Include conditional 115 ; compile variables also. 116 ----------------------------------------------------------------------------*/ 117 118 /*---------------------------------------------------------------------------- 119 ; LOCAL FUNCTION DEFINITIONS 120 ; Function Prototype declaration 121 ----------------------------------------------------------------------------*/ 122 /* private prototypes */ 123 static void idctrow(int16 *blk, uint8 *pred, uint8 *dst, int width); 124 static void idctrow_intra(int16 *blk, PIXEL *, int width); 125 static void idctcol(int16 *blk); 126 127 #ifdef FAST_IDCT 128 // mapping from nz_coefs to functions to be used 129 130 131 // ARM4 does not allow global data when they are not constant hence 132 // an array of function pointers cannot be considered as array of constants 133 // (actual addresses are only known when the dll is loaded). 134 // So instead of arrays of function pointers, we'll store here 135 // arrays of rows or columns and then call the idct function 136 // corresponding to such the row/column number: 137 138 139 static void (*const idctcolVCA[10][4])(int16*) = 140 { 141 {&idctcol1, &idctcol0, &idctcol0, &idctcol0}, 142 {&idctcol1, &idctcol1, &idctcol0, &idctcol0}, 143 {&idctcol2, &idctcol1, &idctcol0, &idctcol0}, 144 {&idctcol3, &idctcol1, &idctcol0, &idctcol0}, 145 {&idctcol3, &idctcol2, &idctcol0, &idctcol0}, 146 {&idctcol3, &idctcol2, &idctcol1, &idctcol0}, 147 {&idctcol3, &idctcol2, &idctcol1, &idctcol1}, 148 {&idctcol3, &idctcol2, &idctcol2, &idctcol1}, 149 {&idctcol3, &idctcol3, &idctcol2, &idctcol1}, 150 {&idctcol4, &idctcol3, &idctcol2, &idctcol1} 151 }; 152 153 154 static void (*const idctrowVCA[10])(int16*, uint8*, uint8*, int) = 155 { 156 &idctrow1, 157 &idctrow2, 158 &idctrow2, 159 &idctrow2, 160 &idctrow2, 161 &idctrow3, 162 &idctrow4, 163 &idctrow4, 164 &idctrow4, 165 &idctrow4 166 }; 167 168 169 static void (*const idctcolVCA2[16])(int16*) = 170 { 171 &idctcol0, &idctcol4, &idctcol3, &idctcol4, 172 &idctcol2, &idctcol4, &idctcol3, &idctcol4, 173 &idctcol1, &idctcol4, &idctcol3, &idctcol4, 174 &idctcol2, &idctcol4, &idctcol3, &idctcol4 175 }; 176 177 static void (*const idctrowVCA2[8])(int16*, uint8*, uint8*, int) = 178 { 179 &idctrow1, &idctrow4, &idctrow3, &idctrow4, 180 &idctrow2, &idctrow4, &idctrow3, &idctrow4 181 }; 182 183 static void (*const idctrowVCA_intra[10])(int16*, PIXEL *, int) = 184 { 185 &idctrow1_intra, 186 &idctrow2_intra, 187 &idctrow2_intra, 188 &idctrow2_intra, 189 &idctrow2_intra, 190 &idctrow3_intra, 191 &idctrow4_intra, 192 &idctrow4_intra, 193 &idctrow4_intra, 194 &idctrow4_intra 195 }; 196 197 static void (*const idctrowVCA2_intra[8])(int16*, PIXEL *, int) = 198 { 199 &idctrow1_intra, &idctrow4_intra, &idctrow3_intra, &idctrow4_intra, 200 &idctrow2_intra, &idctrow4_intra, &idctrow3_intra, &idctrow4_intra 201 }; 202 #endif 203 204 /*---------------------------------------------------------------------------- 205 ; LOCAL STORE/BUFFER/POINTER DEFINITIONS 206 ; Variable declaration - defined here and used outside this module 207 ----------------------------------------------------------------------------*/ 208 209 /*---------------------------------------------------------------------------- 210 ; EXTERNAL FUNCTION REFERENCES 211 ; Declare functions defined elsewhere and referenced in this module 212 ----------------------------------------------------------------------------*/ 213 214 /*---------------------------------------------------------------------------- 215 ; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES 216 ; Declare variables used in this module but defined elsewhere 217 ----------------------------------------------------------------------------*/ 218 219 /*---------------------------------------------------------------------------- 220 ; FUNCTION CODE 221 ----------------------------------------------------------------------------*/ 222 void MBlockIDCT(VideoDecData *video) 223 { 224 Vop *currVop = video->currVop; 225 MacroBlock *mblock = video->mblock; 226 PIXEL *c_comp; 227 PIXEL *cu_comp; 228 PIXEL *cv_comp; 229 int x_pos = video->mbnum_col; 230 int y_pos = video->mbnum_row; 231 int width, width_uv; 232 int32 offset; 233 width = video->width; 234 width_uv = width >> 1; 235 offset = (int32)(y_pos << 4) * width + (x_pos << 4); 236 237 c_comp = currVop->yChan + offset; 238 cu_comp = currVop->uChan + (offset >> 2) + (x_pos << 2); 239 cv_comp = currVop->vChan + (offset >> 2) + (x_pos << 2); 240 241 BlockIDCT_intra(mblock, c_comp, 0, width); 242 BlockIDCT_intra(mblock, c_comp + 8, 1, width); 243 BlockIDCT_intra(mblock, c_comp + (width << 3), 2, width); 244 BlockIDCT_intra(mblock, c_comp + (width << 3) + 8, 3, width); 245 BlockIDCT_intra(mblock, cu_comp, 4, width_uv); 246 BlockIDCT_intra(mblock, cv_comp, 5, width_uv); 247 } 248 249 250 void BlockIDCT_intra( 251 MacroBlock *mblock, PIXEL *c_comp, int comp, int width) 252 { 253 /*---------------------------------------------------------------------------- 254 ; Define all local variables 255 ----------------------------------------------------------------------------*/ 256 int16 *coeff_in = mblock->block[comp]; 257 #ifdef INTEGER_IDCT 258 #ifdef FAST_IDCT /* VCA IDCT using nzcoefs and bitmaps*/ 259 int i, bmapr; 260 int nz_coefs = mblock->no_coeff[comp]; 261 uint8 *bitmapcol = mblock->bitmapcol[comp]; 262 uint8 bitmaprow = mblock->bitmaprow[comp]; 263 264 /*---------------------------------------------------------------------------- 265 ; Function body here 266 ----------------------------------------------------------------------------*/ 267 if (nz_coefs <= 10) 268 { 269 bmapr = (nz_coefs - 1); 270 271 (*(idctcolVCA[bmapr]))(coeff_in); 272 (*(idctcolVCA[bmapr][1]))(coeff_in + 1); 273 (*(idctcolVCA[bmapr][2]))(coeff_in + 2); 274 (*(idctcolVCA[bmapr][3]))(coeff_in + 3); 275 276 (*idctrowVCA_intra[nz_coefs-1])(coeff_in, c_comp, width); 277 } 278 else 279 { 280 i = 8; 281 while (i--) 282 { 283 bmapr = (int)bitmapcol[i]; 284 if (bmapr) 285 { 286 if ((bmapr&0xf) == 0) /* 07/18/01 */ 287 { 288 (*(idctcolVCA2[bmapr>>4]))(coeff_in + i); 289 } 290 else 291 { 292 idctcol(coeff_in + i); 293 } 294 } 295 } 296 if ((bitmapcol[4] | bitmapcol[5] | bitmapcol[6] | bitmapcol[7]) == 0) 297 { 298 bitmaprow >>= 4; 299 (*(idctrowVCA2_intra[(int)bitmaprow]))(coeff_in, c_comp, width); 300 } 301 else 302 { 303 idctrow_intra(coeff_in, c_comp, width); 304 } 305 } 306 #else 307 void idct_intra(int *block, uint8 *comp, int width); 308 idct_intra(coeff_in, c_comp, width); 309 #endif 310 #else 311 void idctref_intra(int *block, uint8 *comp, int width); 312 idctref_intra(coeff_in, c_comp, width); 313 #endif 314 315 316 /*---------------------------------------------------------------------------- 317 ; Return nothing or data or data pointer 318 ----------------------------------------------------------------------------*/ 319 return; 320 } 321 322 /* 08/04/05, no residue, just copy from pred to output */ 323 void Copy_Blk_to_Vop(uint8 *dst, uint8 *pred, int width) 324 { 325 /* copy 4 bytes at a time */ 326 width -= 4; 327 *((uint32*)dst) = *((uint32*)pred); 328 *((uint32*)(dst += 4)) = *((uint32*)(pred += 4)); 329 *((uint32*)(dst += width)) = *((uint32*)(pred += 12)); 330 *((uint32*)(dst += 4)) = *((uint32*)(pred += 4)); 331 *((uint32*)(dst += width)) = *((uint32*)(pred += 12)); 332 *((uint32*)(dst += 4)) = *((uint32*)(pred += 4)); 333 *((uint32*)(dst += width)) = *((uint32*)(pred += 12)); 334 *((uint32*)(dst += 4)) = *((uint32*)(pred += 4)); 335 *((uint32*)(dst += width)) = *((uint32*)(pred += 12)); 336 *((uint32*)(dst += 4)) = *((uint32*)(pred += 4)); 337 *((uint32*)(dst += width)) = *((uint32*)(pred += 12)); 338 *((uint32*)(dst += 4)) = *((uint32*)(pred += 4)); 339 *((uint32*)(dst += width)) = *((uint32*)(pred += 12)); 340 *((uint32*)(dst += 4)) = *((uint32*)(pred += 4)); 341 *((uint32*)(dst += width)) = *((uint32*)(pred += 12)); 342 *((uint32*)(dst += 4)) = *((uint32*)(pred += 4)); 343 344 return ; 345 } 346 347 /* 08/04/05 compute IDCT and add prediction at the end */ 348 void BlockIDCT( 349 uint8 *dst, /* destination */ 350 uint8 *pred, /* prediction block, pitch 16 */ 351 int16 *coeff_in, /* DCT data, size 64 */ 352 int width, /* width of dst */ 353 int nz_coefs, 354 uint8 *bitmapcol, 355 uint8 bitmaprow 356 ) 357 { 358 #ifdef INTEGER_IDCT 359 #ifdef FAST_IDCT /* VCA IDCT using nzcoefs and bitmaps*/ 360 int i, bmapr; 361 /*---------------------------------------------------------------------------- 362 ; Function body here 363 ----------------------------------------------------------------------------*/ 364 if (nz_coefs <= 10) 365 { 366 bmapr = (nz_coefs - 1); 367 (*(idctcolVCA[bmapr]))(coeff_in); 368 (*(idctcolVCA[bmapr][1]))(coeff_in + 1); 369 (*(idctcolVCA[bmapr][2]))(coeff_in + 2); 370 (*(idctcolVCA[bmapr][3]))(coeff_in + 3); 371 372 (*idctrowVCA[nz_coefs-1])(coeff_in, pred, dst, width); 373 return ; 374 } 375 else 376 { 377 i = 8; 378 379 while (i--) 380 { 381 bmapr = (int)bitmapcol[i]; 382 if (bmapr) 383 { 384 if ((bmapr&0xf) == 0) /* 07/18/01 */ 385 { 386 (*(idctcolVCA2[bmapr>>4]))(coeff_in + i); 387 } 388 else 389 { 390 idctcol(coeff_in + i); 391 } 392 } 393 } 394 if ((bitmapcol[4] | bitmapcol[5] | bitmapcol[6] | bitmapcol[7]) == 0) 395 { 396 (*(idctrowVCA2[bitmaprow>>4]))(coeff_in, pred, dst, width); 397 } 398 else 399 { 400 idctrow(coeff_in, pred, dst, width); 401 } 402 return ; 403 } 404 #else // FAST_IDCT 405 void idct(int *block, uint8 *pred, uint8 *dst, int width); 406 idct(coeff_in, pred, dst, width); 407 return; 408 #endif // FAST_IDCT 409 #else // INTEGER_IDCT 410 void idctref(int *block, uint8 *pred, uint8 *dst, int width); 411 idctref(coeff_in, pred, dst, width); 412 return; 413 #endif // INTEGER_IDCT 414 415 } 416 /*---------------------------------------------------------------------------- 417 ; End Function: block_idct 418 ----------------------------------------------------------------------------*/ 419 420 421 /****************************************************************************/ 422 423 /* 424 ------------------------------------------------------------------------------ 425 FUNCTION NAME: idctrow 426 ------------------------------------------------------------------------------ 427 INPUT AND OUTPUT DEFINITIONS FOR idctrow 428 429 Inputs: 430 [input_variable_name] = [description of the input to module, its type 431 definition, and length (when applicable)] 432 433 Local Stores/Buffers/Pointers Needed: 434 [local_store_name] = [description of the local store, its type 435 definition, and length (when applicable)] 436 [local_buffer_name] = [description of the local buffer, its type 437 definition, and length (when applicable)] 438 [local_ptr_name] = [description of the local pointer, its type 439 definition, and length (when applicable)] 440 441 Global Stores/Buffers/Pointers Needed: 442 [global_store_name] = [description of the global store, its type 443 definition, and length (when applicable)] 444 [global_buffer_name] = [description of the global buffer, its type 445 definition, and length (when applicable)] 446 [global_ptr_name] = [description of the global pointer, its type 447 definition, and length (when applicable)] 448 449 Outputs: 450 [return_variable_name] = [description of data/pointer returned 451 by module, its type definition, and length 452 (when applicable)] 453 454 Pointers and Buffers Modified: 455 [variable_bfr_ptr] points to the [describe where the 456 variable_bfr_ptr points to, its type definition, and length 457 (when applicable)] 458 [variable_bfr] contents are [describe the new contents of 459 variable_bfr] 460 461 Local Stores Modified: 462 [local_store_name] = [describe new contents, its type 463 definition, and length (when applicable)] 464 465 Global Stores Modified: 466 [global_store_name] = [describe new contents, its type 467 definition, and length (when applicable)] 468 469 ------------------------------------------------------------------------------ 470 FUNCTION DESCRIPTION FOR idctrow 471 472 ------------------------------------------------------------------------------ 473 REQUIREMENTS FOR idctrow 474 475 ------------------------------------------------------------------------------ 476 REFERENCES FOR idctrow 477 478 ------------------------------------------------------------------------------ 479 PSEUDO-CODE FOR idctrow 480 481 ------------------------------------------------------------------------------ 482 RESOURCES USED FOR idctrow 483 When the code is written for a specific target processor the 484 the resources used should be documented below. 485 486 STACK USAGE: [stack count for this module] + [variable to represent 487 stack usage for each subroutine called] 488 489 where: [stack usage variable] = stack usage for [subroutine 490 name] (see [filename].ext) 491 492 DATA MEMORY USED: x words 493 494 PROGRAM MEMORY USED: x words 495 496 CLOCK CYCLES: [cycle count equation for this module] + [variable 497 used to represent cycle count for each subroutine 498 called] 499 500 where: [cycle count variable] = cycle count for [subroutine 501 name] (see [filename].ext) 502 503 ------------------------------------------------------------------------------ 504 */ 505 506 /*---------------------------------------------------------------------------- 507 ; Function Code FOR idctrow 508 ----------------------------------------------------------------------------*/ 509 void idctrow( 510 int16 *blk, uint8 *pred, uint8 *dst, int width 511 ) 512 { 513 /*---------------------------------------------------------------------------- 514 ; Define all local variables 515 ----------------------------------------------------------------------------*/ 516 int32 x0, x1, x2, x3, x4, x5, x6, x7, x8; 517 int i = 8; 518 uint32 pred_word, dst_word; 519 int res, res2; 520 521 /*---------------------------------------------------------------------------- 522 ; Function body here 523 ----------------------------------------------------------------------------*/ 524 /* row (horizontal) IDCT 525 * 526 * 7 pi 1 dst[k] = sum c[l] * src[l] * cos( -- * 527 * ( k + - ) * l ) l=0 8 2 528 * 529 * where: c[0] = 128 c[1..7] = 128*sqrt(2) */ 530 531 /* preset the offset, such that we can take advantage pre-offset addressing mode */ 532 width -= 4; 533 dst -= width; 534 pred -= 12; 535 blk -= 8; 536 537 while (i--) 538 { 539 x1 = (int32)blk[12] << 8; 540 blk[12] = 0; 541 x2 = blk[14]; 542 blk[14] = 0; 543 x3 = blk[10]; 544 blk[10] = 0; 545 x4 = blk[9]; 546 blk[9] = 0; 547 x5 = blk[15]; 548 blk[15] = 0; 549 x6 = blk[13]; 550 blk[13] = 0; 551 x7 = blk[11]; 552 blk[11] = 0; 553 x0 = ((*(blk += 8)) << 8) + 8192; 554 blk[0] = 0; /* for proper rounding in the fourth stage */ 555 556 /* first stage */ 557 x8 = W7 * (x4 + x5) + 4; 558 x4 = (x8 + (W1 - W7) * x4) >> 3; 559 x5 = (x8 - (W1 + W7) * x5) >> 3; 560 x8 = W3 * (x6 + x7) + 4; 561 x6 = (x8 - (W3 - W5) * x6) >> 3; 562 x7 = (x8 - (W3 + W5) * x7) >> 3; 563 564 /* second stage */ 565 x8 = x0 + x1; 566 x0 -= x1; 567 x1 = W6 * (x3 + x2) + 4; 568 x2 = (x1 - (W2 + W6) * x2) >> 3; 569 x3 = (x1 + (W2 - W6) * x3) >> 3; 570 x1 = x4 + x6; 571 x4 -= x6; 572 x6 = x5 + x7; 573 x5 -= x7; 574 575 /* third stage */ 576 x7 = x8 + x3; 577 x8 -= x3; 578 x3 = x0 + x2; 579 x0 -= x2; 580 x2 = (181 * (x4 + x5) + 128) >> 8; 581 x4 = (181 * (x4 - x5) + 128) >> 8; 582 583 /* fourth stage */ 584 pred_word = *((uint32*)(pred += 12)); /* read 4 bytes from pred */ 585 586 res = (x7 + x1) >> 14; 587 ADD_AND_CLIP1(res); 588 res2 = (x3 + x2) >> 14; 589 ADD_AND_CLIP2(res2); 590 dst_word = (res2 << 8) | res; 591 res = (x0 + x4) >> 14; 592 ADD_AND_CLIP3(res); 593 dst_word |= (res << 16); 594 res = (x8 + x6) >> 14; 595 ADD_AND_CLIP4(res); 596 dst_word |= (res << 24); 597 *((uint32*)(dst += width)) = dst_word; /* save 4 bytes to dst */ 598 599 pred_word = *((uint32*)(pred += 4)); /* read 4 bytes from pred */ 600 601 res = (x8 - x6) >> 14; 602 ADD_AND_CLIP1(res); 603 res2 = (x0 - x4) >> 14; 604 ADD_AND_CLIP2(res2); 605 dst_word = (res2 << 8) | res; 606 res = (x3 - x2) >> 14; 607 ADD_AND_CLIP3(res); 608 dst_word |= (res << 16); 609 res = (x7 - x1) >> 14; 610 ADD_AND_CLIP4(res); 611 dst_word |= (res << 24); 612 *((uint32*)(dst += 4)) = dst_word; /* save 4 bytes to dst */ 613 } 614 /*---------------------------------------------------------------------------- 615 ; Return nothing or data or data pointer 616 ----------------------------------------------------------------------------*/ 617 return; 618 } 619 620 void idctrow_intra( 621 int16 *blk, PIXEL *comp, int width 622 ) 623 { 624 /*---------------------------------------------------------------------------- 625 ; Define all local variables 626 ----------------------------------------------------------------------------*/ 627 int32 x0, x1, x2, x3, x4, x5, x6, x7, x8, temp; 628 int i = 8; 629 int offset = width; 630 int32 word; 631 632 /*---------------------------------------------------------------------------- 633 ; Function body here 634 ----------------------------------------------------------------------------*/ 635 /* row (horizontal) IDCT 636 * 637 * 7 pi 1 dst[k] = sum c[l] * src[l] * cos( -- * 638 * ( k + - ) * l ) l=0 8 2 639 * 640 * where: c[0] = 128 c[1..7] = 128*sqrt(2) */ 641 while (i--) 642 { 643 x1 = (int32)blk[4] << 8; 644 blk[4] = 0; 645 x2 = blk[6]; 646 blk[6] = 0; 647 x3 = blk[2]; 648 blk[2] = 0; 649 x4 = blk[1]; 650 blk[1] = 0; 651 x5 = blk[7]; 652 blk[7] = 0; 653 x6 = blk[5]; 654 blk[5] = 0; 655 x7 = blk[3]; 656 blk[3] = 0; 657 #ifndef FAST_IDCT 658 /* shortcut */ /* covered by idctrow1 01/9/2001 */ 659 if (!(x1 | x2 | x3 | x4 | x5 | x6 | x7)) 660 { 661 blk[0] = blk[1] = blk[2] = blk[3] = blk[4] = blk[5] = blk[6] = blk[7] = (blk[0] + 32) >> 6; 662 return; 663 } 664 #endif 665 x0 = ((int32)blk[0] << 8) + 8192; 666 blk[0] = 0; /* for proper rounding in the fourth stage */ 667 668 /* first stage */ 669 x8 = W7 * (x4 + x5) + 4; 670 x4 = (x8 + (W1 - W7) * x4) >> 3; 671 x5 = (x8 - (W1 + W7) * x5) >> 3; 672 x8 = W3 * (x6 + x7) + 4; 673 x6 = (x8 - (W3 - W5) * x6) >> 3; 674 x7 = (x8 - (W3 + W5) * x7) >> 3; 675 676 /* second stage */ 677 x8 = x0 + x1; 678 x0 -= x1; 679 x1 = W6 * (x3 + x2) + 4; 680 x2 = (x1 - (W2 + W6) * x2) >> 3; 681 x3 = (x1 + (W2 - W6) * x3) >> 3; 682 x1 = x4 + x6; 683 x4 -= x6; 684 x6 = x5 + x7; 685 x5 -= x7; 686 687 /* third stage */ 688 x7 = x8 + x3; 689 x8 -= x3; 690 x3 = x0 + x2; 691 x0 -= x2; 692 x2 = (181 * (x4 + x5) + 128) >> 8; 693 x4 = (181 * (x4 - x5) + 128) >> 8; 694 695 /* fourth stage */ 696 word = ((x7 + x1) >> 14); 697 CLIP_RESULT(word) 698 699 temp = ((x3 + x2) >> 14); 700 CLIP_RESULT(temp) 701 word = word | (temp << 8); 702 703 temp = ((x0 + x4) >> 14); 704 CLIP_RESULT(temp) 705 word = word | (temp << 16); 706 707 temp = ((x8 + x6) >> 14); 708 CLIP_RESULT(temp) 709 word = word | (temp << 24); 710 *((int32*)(comp)) = word; 711 712 word = ((x8 - x6) >> 14); 713 CLIP_RESULT(word) 714 715 temp = ((x0 - x4) >> 14); 716 CLIP_RESULT(temp) 717 word = word | (temp << 8); 718 719 temp = ((x3 - x2) >> 14); 720 CLIP_RESULT(temp) 721 word = word | (temp << 16); 722 723 temp = ((x7 - x1) >> 14); 724 CLIP_RESULT(temp) 725 word = word | (temp << 24); 726 *((int32*)(comp + 4)) = word; 727 comp += offset; 728 729 blk += B_SIZE; 730 } 731 /*---------------------------------------------------------------------------- 732 ; Return nothing or data or data pointer 733 ----------------------------------------------------------------------------*/ 734 return; 735 } 736 737 /*---------------------------------------------------------------------------- 738 ; End Function: idctrow 739 ----------------------------------------------------------------------------*/ 740 741 742 /****************************************************************************/ 743 744 /* 745 ------------------------------------------------------------------------------ 746 FUNCTION NAME: idctcol 747 ------------------------------------------------------------------------------ 748 INPUT AND OUTPUT DEFINITIONS FOR idctcol 749 750 Inputs: 751 [input_variable_name] = [description of the input to module, its type 752 definition, and length (when applicable)] 753 754 Local Stores/Buffers/Pointers Needed: 755 [local_store_name] = [description of the local store, its type 756 definition, and length (when applicable)] 757 [local_buffer_name] = [description of the local buffer, its type 758 definition, and length (when applicable)] 759 [local_ptr_name] = [description of the local pointer, its type 760 definition, and length (when applicable)] 761 762 Global Stores/Buffers/Pointers Needed: 763 [global_store_name] = [description of the global store, its type 764 definition, and length (when applicable)] 765 [global_buffer_name] = [description of the global buffer, its type 766 definition, and length (when applicable)] 767 [global_ptr_name] = [description of the global pointer, its type 768 definition, and length (when applicable)] 769 770 Outputs: 771 [return_variable_name] = [description of data/pointer returned 772 by module, its type definition, and length 773 (when applicable)] 774 775 Pointers and Buffers Modified: 776 [variable_bfr_ptr] points to the [describe where the 777 variable_bfr_ptr points to, its type definition, and length 778 (when applicable)] 779 [variable_bfr] contents are [describe the new contents of 780 variable_bfr] 781 782 Local Stores Modified: 783 [local_store_name] = [describe new contents, its type 784 definition, and length (when applicable)] 785 786 Global Stores Modified: 787 [global_store_name] = [describe new contents, its type 788 definition, and length (when applicable)] 789 790 ------------------------------------------------------------------------------ 791 FUNCTION DESCRIPTION FOR idctcol 792 793 ------------------------------------------------------------------------------ 794 REQUIREMENTS FOR idctcol 795 796 ------------------------------------------------------------------------------ 797 REFERENCES FOR idctcol 798 799 ------------------------------------------------------------------------------ 800 PSEUDO-CODE FOR idctcol 801 802 ------------------------------------------------------------------------------ 803 RESOURCES USED FOR idctcol 804 When the code is written for a specific target processor the 805 the resources used should be documented below. 806 807 STACK USAGE: [stack count for this module] + [variable to represent 808 stack usage for each subroutine called] 809 810 where: [stack usage variable] = stack usage for [subroutine 811 name] (see [filename].ext) 812 813 DATA MEMORY USED: x words 814 815 PROGRAM MEMORY USED: x words 816 817 CLOCK CYCLES: [cycle count equation for this module] + [variable 818 used to represent cycle count for each subroutine 819 called] 820 821 where: [cycle count variable] = cycle count for [subroutine 822 name] (see [filename].ext) 823 824 ------------------------------------------------------------------------------ 825 */ 826 827 /*---------------------------------------------------------------------------- 828 ; Function Code FOR idctcol 829 ----------------------------------------------------------------------------*/ 830 void idctcol( 831 int16 *blk 832 ) 833 { 834 /*---------------------------------------------------------------------------- 835 ; Define all local variables 836 ----------------------------------------------------------------------------*/ 837 int32 x0, x1, x2, x3, x4, x5, x6, x7, x8; 838 839 /*---------------------------------------------------------------------------- 840 ; Function body here 841 ----------------------------------------------------------------------------*/ 842 /* column (vertical) IDCT 843 * 844 * 7 pi 1 dst[8*k] = sum c[l] * src[8*l] * 845 * cos( -- * ( k + - ) * l ) l=0 8 2 846 * 847 * where: c[0] = 1/1024 c[1..7] = (1/1024)*sqrt(2) */ 848 x1 = (int32)blk[32] << 11; 849 x2 = blk[48]; 850 x3 = blk[16]; 851 x4 = blk[8]; 852 x5 = blk[56]; 853 x6 = blk[40]; 854 x7 = blk[24]; 855 #ifndef FAST_IDCT 856 /* shortcut */ /* covered by idctcolumn1 01/9/2001 */ 857 if (!(x1 | x2 | x3 | x4 | x5 | x6 | x7)) 858 { 859 blk[0] = blk[8] = blk[16] = blk[24] = blk[32] = blk[40] = blk[48] = blk[56] 860 = blk[0] << 3; 861 return; 862 } 863 #endif 864 865 x0 = ((int32)blk[0] << 11) + 128; 866 867 /* first stage */ 868 x8 = W7 * (x4 + x5); 869 x4 = x8 + (W1 - W7) * x4; 870 x5 = x8 - (W1 + W7) * x5; 871 x8 = W3 * (x6 + x7); 872 x6 = x8 - (W3 - W5) * x6; 873 x7 = x8 - (W3 + W5) * x7; 874 875 /* second stage */ 876 x8 = x0 + x1; 877 x0 -= x1; 878 x1 = W6 * (x3 + x2); 879 x2 = x1 - (W2 + W6) * x2; 880 x3 = x1 + (W2 - W6) * x3; 881 x1 = x4 + x6; 882 x4 -= x6; 883 x6 = x5 + x7; 884 x5 -= x7; 885 886 /* third stage */ 887 x7 = x8 + x3; 888 x8 -= x3; 889 x3 = x0 + x2; 890 x0 -= x2; 891 x2 = (181 * (x4 + x5) + 128) >> 8; 892 x4 = (181 * (x4 - x5) + 128) >> 8; 893 894 /* fourth stage */ 895 blk[0] = (x7 + x1) >> 8; 896 blk[8] = (x3 + x2) >> 8; 897 blk[16] = (x0 + x4) >> 8; 898 blk[24] = (x8 + x6) >> 8; 899 blk[32] = (x8 - x6) >> 8; 900 blk[40] = (x0 - x4) >> 8; 901 blk[48] = (x3 - x2) >> 8; 902 blk[56] = (x7 - x1) >> 8; 903 /*---------------------------------------------------------------------------- 904 ; Return nothing or data or data pointer 905 ----------------------------------------------------------------------------*/ 906 return; 907 } 908 /*---------------------------------------------------------------------------- 909 ; End Function: idctcol 910 ----------------------------------------------------------------------------*/ 911 912
