1 /* 2 * jidctint.c 3 * 4 * Copyright (C) 1991-1998, Thomas G. Lane. 5 * Modification developed 2002-2009 by Guido Vollbeding. 6 * This file is part of the Independent JPEG Group's software. 7 * For conditions of distribution and use, see the accompanying README file. 8 * 9 * This file contains a slow-but-accurate integer implementation of the 10 * inverse DCT (Discrete Cosine Transform). In the IJG code, this routine 11 * must also perform dequantization of the input coefficients. 12 * 13 * A 2-D IDCT can be done by 1-D IDCT on each column followed by 1-D IDCT 14 * on each row (or vice versa, but it's more convenient to emit a row at 15 * a time). Direct algorithms are also available, but they are much more 16 * complex and seem not to be any faster when reduced to code. 17 * 18 * This implementation is based on an algorithm described in 19 * C. Loeffler, A. Ligtenberg and G. Moschytz, "Practical Fast 1-D DCT 20 * Algorithms with 11 Multiplications", Proc. Int'l. Conf. on Acoustics, 21 * Speech, and Signal Processing 1989 (ICASSP '89), pp. 988-991. 22 * The primary algorithm described there uses 11 multiplies and 29 adds. 23 * We use their alternate method with 12 multiplies and 32 adds. 24 * The advantage of this method is that no data path contains more than one 25 * multiplication; this allows a very simple and accurate implementation in 26 * scaled fixed-point arithmetic, with a minimal number of shifts. 27 * 28 * We also provide IDCT routines with various output sample block sizes for 29 * direct resolution reduction or enlargement and for direct resolving the 30 * common 2x1 and 1x2 subsampling cases without additional resampling: NxN 31 * (N=1...16), 2NxN, and Nx2N (N=1...8) pixels for one 8x8 input DCT block. 32 * 33 * For N<8 we simply take the corresponding low-frequency coefficients of 34 * the 8x8 input DCT block and apply an NxN point IDCT on the sub-block 35 * to yield the downscaled outputs. 36 * This can be seen as direct low-pass downsampling from the DCT domain 37 * point of view rather than the usual spatial domain point of view, 38 * yielding significant computational savings and results at least 39 * as good as common bilinear (averaging) spatial downsampling. 40 * 41 * For N>8 we apply a partial NxN IDCT on the 8 input coefficients as 42 * lower frequencies and higher frequencies assumed to be zero. 43 * It turns out that the computational effort is similar to the 8x8 IDCT 44 * regarding the output size. 45 * Furthermore, the scaling and descaling is the same for all IDCT sizes. 46 * 47 * CAUTION: We rely on the FIX() macro except for the N=1,2,4,8 cases 48 * since there would be too many additional constants to pre-calculate. 49 */ 50 51 #define JPEG_INTERNALS 52 #include "jinclude.h" 53 #include "jpeglib.h" 54 #include "jdct.h" /* Private declarations for DCT subsystem */ 55 56 #ifdef DCT_ISLOW_SUPPORTED 57 58 59 /* 60 * This module is specialized to the case DCTSIZE = 8. 61 */ 62 63 #if DCTSIZE != 8 64 Sorry, this code only copes with 8x8 DCT blocks. /* deliberate syntax err */ 65 #endif 66 67 68 /* 69 * The poop on this scaling stuff is as follows: 70 * 71 * Each 1-D IDCT step produces outputs which are a factor of sqrt(N) 72 * larger than the true IDCT outputs. The final outputs are therefore 73 * a factor of N larger than desired; since N=8 this can be cured by 74 * a simple right shift at the end of the algorithm. The advantage of 75 * this arrangement is that we save two multiplications per 1-D IDCT, 76 * because the y0 and y4 inputs need not be divided by sqrt(N). 77 * 78 * We have to do addition and subtraction of the integer inputs, which 79 * is no problem, and multiplication by fractional constants, which is 80 * a problem to do in integer arithmetic. We multiply all the constants 81 * by CONST_SCALE and convert them to integer constants (thus retaining 82 * CONST_BITS bits of precision in the constants). After doing a 83 * multiplication we have to divide the product by CONST_SCALE, with proper 84 * rounding, to produce the correct output. This division can be done 85 * cheaply as a right shift of CONST_BITS bits. We postpone shifting 86 * as long as possible so that partial sums can be added together with 87 * full fractional precision. 88 * 89 * The outputs of the first pass are scaled up by PASS1_BITS bits so that 90 * they are represented to better-than-integral precision. These outputs 91 * require BITS_IN_JSAMPLE + PASS1_BITS + 3 bits; this fits in a 16-bit word 92 * with the recommended scaling. (To scale up 12-bit sample data further, an 93 * intermediate INT32 array would be needed.) 94 * 95 * To avoid overflow of the 32-bit intermediate results in pass 2, we must 96 * have BITS_IN_JSAMPLE + CONST_BITS + PASS1_BITS <= 26. Error analysis 97 * shows that the values given below are the most effective. 98 */ 99 100 #if BITS_IN_JSAMPLE == 8 101 #define CONST_BITS 13 102 #define PASS1_BITS 2 103 #else 104 #define CONST_BITS 13 105 #define PASS1_BITS 1 /* lose a little precision to avoid overflow */ 106 #endif 107 108 /* Some C compilers fail to reduce "FIX(constant)" at compile time, thus 109 * causing a lot of useless floating-point operations at run time. 110 * To get around this we use the following pre-calculated constants. 111 * If you change CONST_BITS you may want to add appropriate values. 112 * (With a reasonable C compiler, you can just rely on the FIX() macro...) 113 */ 114 115 #if CONST_BITS == 13 116 #define FIX_0_298631336 ((INT32) 2446) /* FIX(0.298631336) */ 117 #define FIX_0_390180644 ((INT32) 3196) /* FIX(0.390180644) */ 118 #define FIX_0_541196100 ((INT32) 4433) /* FIX(0.541196100) */ 119 #define FIX_0_765366865 ((INT32) 6270) /* FIX(0.765366865) */ 120 #define FIX_0_899976223 ((INT32) 7373) /* FIX(0.899976223) */ 121 #define FIX_1_175875602 ((INT32) 9633) /* FIX(1.175875602) */ 122 #define FIX_1_501321110 ((INT32) 12299) /* FIX(1.501321110) */ 123 #define FIX_1_847759065 ((INT32) 15137) /* FIX(1.847759065) */ 124 #define FIX_1_961570560 ((INT32) 16069) /* FIX(1.961570560) */ 125 #define FIX_2_053119869 ((INT32) 16819) /* FIX(2.053119869) */ 126 #define FIX_2_562915447 ((INT32) 20995) /* FIX(2.562915447) */ 127 #define FIX_3_072711026 ((INT32) 25172) /* FIX(3.072711026) */ 128 #else 129 #define FIX_0_298631336 FIX(0.298631336) 130 #define FIX_0_390180644 FIX(0.390180644) 131 #define FIX_0_541196100 FIX(0.541196100) 132 #define FIX_0_765366865 FIX(0.765366865) 133 #define FIX_0_899976223 FIX(0.899976223) 134 #define FIX_1_175875602 FIX(1.175875602) 135 #define FIX_1_501321110 FIX(1.501321110) 136 #define FIX_1_847759065 FIX(1.847759065) 137 #define FIX_1_961570560 FIX(1.961570560) 138 #define FIX_2_053119869 FIX(2.053119869) 139 #define FIX_2_562915447 FIX(2.562915447) 140 #define FIX_3_072711026 FIX(3.072711026) 141 #endif 142 143 144 /* Multiply an INT32 variable by an INT32 constant to yield an INT32 result. 145 * For 8-bit samples with the recommended scaling, all the variable 146 * and constant values involved are no more than 16 bits wide, so a 147 * 16x16->32 bit multiply can be used instead of a full 32x32 multiply. 148 * For 12-bit samples, a full 32-bit multiplication will be needed. 149 */ 150 151 #if BITS_IN_JSAMPLE == 8 152 #define MULTIPLY(var,const) MULTIPLY16C16(var,const) 153 #else 154 #define MULTIPLY(var,const) ((var) * (const)) 155 #endif 156 157 158 /* Dequantize a coefficient by multiplying it by the multiplier-table 159 * entry; produce an int result. In this module, both inputs and result 160 * are 16 bits or less, so either int or short multiply will work. 161 */ 162 163 #define DEQUANTIZE(coef,quantval) (((ISLOW_MULT_TYPE) (coef)) * (quantval)) 164 165 166 /* 167 * Perform dequantization and inverse DCT on one block of coefficients. 168 */ 169 170 GLOBAL(void) 171 jpeg_idct_islow (j_decompress_ptr cinfo, jpeg_component_info * compptr, 172 JCOEFPTR coef_block, 173 JSAMPARRAY output_buf, JDIMENSION output_col) 174 { 175 INT32 tmp0, tmp1, tmp2, tmp3; 176 INT32 tmp10, tmp11, tmp12, tmp13; 177 INT32 z1, z2, z3; 178 JCOEFPTR inptr; 179 ISLOW_MULT_TYPE * quantptr; 180 int * wsptr; 181 JSAMPROW outptr; 182 JSAMPLE *range_limit = IDCT_range_limit(cinfo); 183 int ctr; 184 int workspace[DCTSIZE2]; /* buffers data between passes */ 185 SHIFT_TEMPS 186 187 /* Pass 1: process columns from input, store into work array. */ 188 /* Note results are scaled up by sqrt(8) compared to a true IDCT; */ 189 /* furthermore, we scale the results by 2**PASS1_BITS. */ 190 191 inptr = coef_block; 192 quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 193 wsptr = workspace; 194 for (ctr = DCTSIZE; ctr > 0; ctr--) { 195 /* Due to quantization, we will usually find that many of the input 196 * coefficients are zero, especially the AC terms. We can exploit this 197 * by short-circuiting the IDCT calculation for any column in which all 198 * the AC terms are zero. In that case each output is equal to the 199 * DC coefficient (with scale factor as needed). 200 * With typical images and quantization tables, half or more of the 201 * column DCT calculations can be simplified this way. 202 */ 203 204 if (inptr[DCTSIZE*1] == 0 && inptr[DCTSIZE*2] == 0 && 205 inptr[DCTSIZE*3] == 0 && inptr[DCTSIZE*4] == 0 && 206 inptr[DCTSIZE*5] == 0 && inptr[DCTSIZE*6] == 0 && 207 inptr[DCTSIZE*7] == 0) { 208 /* AC terms all zero */ 209 int dcval = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]) << PASS1_BITS; 210 211 wsptr[DCTSIZE*0] = dcval; 212 wsptr[DCTSIZE*1] = dcval; 213 wsptr[DCTSIZE*2] = dcval; 214 wsptr[DCTSIZE*3] = dcval; 215 wsptr[DCTSIZE*4] = dcval; 216 wsptr[DCTSIZE*5] = dcval; 217 wsptr[DCTSIZE*6] = dcval; 218 wsptr[DCTSIZE*7] = dcval; 219 220 inptr++; /* advance pointers to next column */ 221 quantptr++; 222 wsptr++; 223 continue; 224 } 225 226 /* Even part: reverse the even part of the forward DCT. */ 227 /* The rotator is sqrt(2)*c(-6). */ 228 229 z2 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]); 230 z3 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]); 231 232 z1 = MULTIPLY(z2 + z3, FIX_0_541196100); 233 tmp2 = z1 + MULTIPLY(z2, FIX_0_765366865); 234 tmp3 = z1 - MULTIPLY(z3, FIX_1_847759065); 235 236 z2 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); 237 z3 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]); 238 z2 <<= CONST_BITS; 239 z3 <<= CONST_BITS; 240 /* Add fudge factor here for final descale. */ 241 z2 += ONE << (CONST_BITS-PASS1_BITS-1); 242 243 tmp0 = z2 + z3; 244 tmp1 = z2 - z3; 245 246 tmp10 = tmp0 + tmp2; 247 tmp13 = tmp0 - tmp2; 248 tmp11 = tmp1 + tmp3; 249 tmp12 = tmp1 - tmp3; 250 251 /* Odd part per figure 8; the matrix is unitary and hence its 252 * transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively. 253 */ 254 255 tmp0 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]); 256 tmp1 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]); 257 tmp2 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]); 258 tmp3 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); 259 260 z2 = tmp0 + tmp2; 261 z3 = tmp1 + tmp3; 262 263 z1 = MULTIPLY(z2 + z3, FIX_1_175875602); /* sqrt(2) * c3 */ 264 z2 = MULTIPLY(z2, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */ 265 z3 = MULTIPLY(z3, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */ 266 z2 += z1; 267 z3 += z1; 268 269 z1 = MULTIPLY(tmp0 + tmp3, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */ 270 tmp0 = MULTIPLY(tmp0, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */ 271 tmp3 = MULTIPLY(tmp3, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */ 272 tmp0 += z1 + z2; 273 tmp3 += z1 + z3; 274 275 z1 = MULTIPLY(tmp1 + tmp2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */ 276 tmp1 = MULTIPLY(tmp1, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */ 277 tmp2 = MULTIPLY(tmp2, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */ 278 tmp1 += z1 + z3; 279 tmp2 += z1 + z2; 280 281 /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */ 282 283 wsptr[DCTSIZE*0] = (int) RIGHT_SHIFT(tmp10 + tmp3, CONST_BITS-PASS1_BITS); 284 wsptr[DCTSIZE*7] = (int) RIGHT_SHIFT(tmp10 - tmp3, CONST_BITS-PASS1_BITS); 285 wsptr[DCTSIZE*1] = (int) RIGHT_SHIFT(tmp11 + tmp2, CONST_BITS-PASS1_BITS); 286 wsptr[DCTSIZE*6] = (int) RIGHT_SHIFT(tmp11 - tmp2, CONST_BITS-PASS1_BITS); 287 wsptr[DCTSIZE*2] = (int) RIGHT_SHIFT(tmp12 + tmp1, CONST_BITS-PASS1_BITS); 288 wsptr[DCTSIZE*5] = (int) RIGHT_SHIFT(tmp12 - tmp1, CONST_BITS-PASS1_BITS); 289 wsptr[DCTSIZE*3] = (int) RIGHT_SHIFT(tmp13 + tmp0, CONST_BITS-PASS1_BITS); 290 wsptr[DCTSIZE*4] = (int) RIGHT_SHIFT(tmp13 - tmp0, CONST_BITS-PASS1_BITS); 291 292 inptr++; /* advance pointers to next column */ 293 quantptr++; 294 wsptr++; 295 } 296 297 /* Pass 2: process rows from work array, store into output array. */ 298 /* Note that we must descale the results by a factor of 8 == 2**3, */ 299 /* and also undo the PASS1_BITS scaling. */ 300 301 wsptr = workspace; 302 for (ctr = 0; ctr < DCTSIZE; ctr++) { 303 outptr = output_buf[ctr] + output_col; 304 /* Rows of zeroes can be exploited in the same way as we did with columns. 305 * However, the column calculation has created many nonzero AC terms, so 306 * the simplification applies less often (typically 5% to 10% of the time). 307 * On machines with very fast multiplication, it's possible that the 308 * test takes more time than it's worth. In that case this section 309 * may be commented out. 310 */ 311 312 #ifndef NO_ZERO_ROW_TEST 313 if (wsptr[1] == 0 && wsptr[2] == 0 && wsptr[3] == 0 && wsptr[4] == 0 && 314 wsptr[5] == 0 && wsptr[6] == 0 && wsptr[7] == 0) { 315 /* AC terms all zero */ 316 JSAMPLE dcval = range_limit[(int) DESCALE((INT32) wsptr[0], PASS1_BITS+3) 317 & RANGE_MASK]; 318 319 outptr[0] = dcval; 320 outptr[1] = dcval; 321 outptr[2] = dcval; 322 outptr[3] = dcval; 323 outptr[4] = dcval; 324 outptr[5] = dcval; 325 outptr[6] = dcval; 326 outptr[7] = dcval; 327 328 wsptr += DCTSIZE; /* advance pointer to next row */ 329 continue; 330 } 331 #endif 332 333 /* Even part: reverse the even part of the forward DCT. */ 334 /* The rotator is sqrt(2)*c(-6). */ 335 336 z2 = (INT32) wsptr[2]; 337 z3 = (INT32) wsptr[6]; 338 339 z1 = MULTIPLY(z2 + z3, FIX_0_541196100); 340 tmp2 = z1 + MULTIPLY(z2, FIX_0_765366865); 341 tmp3 = z1 - MULTIPLY(z3, FIX_1_847759065); 342 343 /* Add fudge factor here for final descale. */ 344 z2 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2)); 345 z3 = (INT32) wsptr[4]; 346 347 tmp0 = (z2 + z3) << CONST_BITS; 348 tmp1 = (z2 - z3) << CONST_BITS; 349 350 tmp10 = tmp0 + tmp2; 351 tmp13 = tmp0 - tmp2; 352 tmp11 = tmp1 + tmp3; 353 tmp12 = tmp1 - tmp3; 354 355 /* Odd part per figure 8; the matrix is unitary and hence its 356 * transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively. 357 */ 358 359 tmp0 = (INT32) wsptr[7]; 360 tmp1 = (INT32) wsptr[5]; 361 tmp2 = (INT32) wsptr[3]; 362 tmp3 = (INT32) wsptr[1]; 363 364 z2 = tmp0 + tmp2; 365 z3 = tmp1 + tmp3; 366 367 z1 = MULTIPLY(z2 + z3, FIX_1_175875602); /* sqrt(2) * c3 */ 368 z2 = MULTIPLY(z2, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */ 369 z3 = MULTIPLY(z3, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */ 370 z2 += z1; 371 z3 += z1; 372 373 z1 = MULTIPLY(tmp0 + tmp3, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */ 374 tmp0 = MULTIPLY(tmp0, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */ 375 tmp3 = MULTIPLY(tmp3, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */ 376 tmp0 += z1 + z2; 377 tmp3 += z1 + z3; 378 379 z1 = MULTIPLY(tmp1 + tmp2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */ 380 tmp1 = MULTIPLY(tmp1, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */ 381 tmp2 = MULTIPLY(tmp2, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */ 382 tmp1 += z1 + z3; 383 tmp2 += z1 + z2; 384 385 /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */ 386 387 outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp10 + tmp3, 388 CONST_BITS+PASS1_BITS+3) 389 & RANGE_MASK]; 390 outptr[7] = range_limit[(int) RIGHT_SHIFT(tmp10 - tmp3, 391 CONST_BITS+PASS1_BITS+3) 392 & RANGE_MASK]; 393 outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp11 + tmp2, 394 CONST_BITS+PASS1_BITS+3) 395 & RANGE_MASK]; 396 outptr[6] = range_limit[(int) RIGHT_SHIFT(tmp11 - tmp2, 397 CONST_BITS+PASS1_BITS+3) 398 & RANGE_MASK]; 399 outptr[2] = range_limit[(int) RIGHT_SHIFT(tmp12 + tmp1, 400 CONST_BITS+PASS1_BITS+3) 401 & RANGE_MASK]; 402 outptr[5] = range_limit[(int) RIGHT_SHIFT(tmp12 - tmp1, 403 CONST_BITS+PASS1_BITS+3) 404 & RANGE_MASK]; 405 outptr[3] = range_limit[(int) RIGHT_SHIFT(tmp13 + tmp0, 406 CONST_BITS+PASS1_BITS+3) 407 & RANGE_MASK]; 408 outptr[4] = range_limit[(int) RIGHT_SHIFT(tmp13 - tmp0, 409 CONST_BITS+PASS1_BITS+3) 410 & RANGE_MASK]; 411 412 wsptr += DCTSIZE; /* advance pointer to next row */ 413 } 414 } 415 416 #ifdef IDCT_SCALING_SUPPORTED 417 418 419 /* 420 * Perform dequantization and inverse DCT on one block of coefficients, 421 * producing a 7x7 output block. 422 * 423 * Optimized algorithm with 12 multiplications in the 1-D kernel. 424 * cK represents sqrt(2) * cos(K*pi/14). 425 */ 426 427 GLOBAL(void) 428 jpeg_idct_7x7 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 429 JCOEFPTR coef_block, 430 JSAMPARRAY output_buf, JDIMENSION output_col) 431 { 432 INT32 tmp0, tmp1, tmp2, tmp10, tmp11, tmp12, tmp13; 433 INT32 z1, z2, z3; 434 JCOEFPTR inptr; 435 ISLOW_MULT_TYPE * quantptr; 436 int * wsptr; 437 JSAMPROW outptr; 438 JSAMPLE *range_limit = IDCT_range_limit(cinfo); 439 int ctr; 440 int workspace[7*7]; /* buffers data between passes */ 441 SHIFT_TEMPS 442 443 /* Pass 1: process columns from input, store into work array. */ 444 445 inptr = coef_block; 446 quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 447 wsptr = workspace; 448 for (ctr = 0; ctr < 7; ctr++, inptr++, quantptr++, wsptr++) { 449 /* Even part */ 450 451 tmp13 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); 452 tmp13 <<= CONST_BITS; 453 /* Add fudge factor here for final descale. */ 454 tmp13 += ONE << (CONST_BITS-PASS1_BITS-1); 455 456 z1 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]); 457 z2 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]); 458 z3 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]); 459 460 tmp10 = MULTIPLY(z2 - z3, FIX(0.881747734)); /* c4 */ 461 tmp12 = MULTIPLY(z1 - z2, FIX(0.314692123)); /* c6 */ 462 tmp11 = tmp10 + tmp12 + tmp13 - MULTIPLY(z2, FIX(1.841218003)); /* c2+c4-c6 */ 463 tmp0 = z1 + z3; 464 z2 -= tmp0; 465 tmp0 = MULTIPLY(tmp0, FIX(1.274162392)) + tmp13; /* c2 */ 466 tmp10 += tmp0 - MULTIPLY(z3, FIX(0.077722536)); /* c2-c4-c6 */ 467 tmp12 += tmp0 - MULTIPLY(z1, FIX(2.470602249)); /* c2+c4+c6 */ 468 tmp13 += MULTIPLY(z2, FIX(1.414213562)); /* c0 */ 469 470 /* Odd part */ 471 472 z1 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); 473 z2 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]); 474 z3 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]); 475 476 tmp1 = MULTIPLY(z1 + z2, FIX(0.935414347)); /* (c3+c1-c5)/2 */ 477 tmp2 = MULTIPLY(z1 - z2, FIX(0.170262339)); /* (c3+c5-c1)/2 */ 478 tmp0 = tmp1 - tmp2; 479 tmp1 += tmp2; 480 tmp2 = MULTIPLY(z2 + z3, - FIX(1.378756276)); /* -c1 */ 481 tmp1 += tmp2; 482 z2 = MULTIPLY(z1 + z3, FIX(0.613604268)); /* c5 */ 483 tmp0 += z2; 484 tmp2 += z2 + MULTIPLY(z3, FIX(1.870828693)); /* c3+c1-c5 */ 485 486 /* Final output stage */ 487 488 wsptr[7*0] = (int) RIGHT_SHIFT(tmp10 + tmp0, CONST_BITS-PASS1_BITS); 489 wsptr[7*6] = (int) RIGHT_SHIFT(tmp10 - tmp0, CONST_BITS-PASS1_BITS); 490 wsptr[7*1] = (int) RIGHT_SHIFT(tmp11 + tmp1, CONST_BITS-PASS1_BITS); 491 wsptr[7*5] = (int) RIGHT_SHIFT(tmp11 - tmp1, CONST_BITS-PASS1_BITS); 492 wsptr[7*2] = (int) RIGHT_SHIFT(tmp12 + tmp2, CONST_BITS-PASS1_BITS); 493 wsptr[7*4] = (int) RIGHT_SHIFT(tmp12 - tmp2, CONST_BITS-PASS1_BITS); 494 wsptr[7*3] = (int) RIGHT_SHIFT(tmp13, CONST_BITS-PASS1_BITS); 495 } 496 497 /* Pass 2: process 7 rows from work array, store into output array. */ 498 499 wsptr = workspace; 500 for (ctr = 0; ctr < 7; ctr++) { 501 outptr = output_buf[ctr] + output_col; 502 503 /* Even part */ 504 505 /* Add fudge factor here for final descale. */ 506 tmp13 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2)); 507 tmp13 <<= CONST_BITS; 508 509 z1 = (INT32) wsptr[2]; 510 z2 = (INT32) wsptr[4]; 511 z3 = (INT32) wsptr[6]; 512 513 tmp10 = MULTIPLY(z2 - z3, FIX(0.881747734)); /* c4 */ 514 tmp12 = MULTIPLY(z1 - z2, FIX(0.314692123)); /* c6 */ 515 tmp11 = tmp10 + tmp12 + tmp13 - MULTIPLY(z2, FIX(1.841218003)); /* c2+c4-c6 */ 516 tmp0 = z1 + z3; 517 z2 -= tmp0; 518 tmp0 = MULTIPLY(tmp0, FIX(1.274162392)) + tmp13; /* c2 */ 519 tmp10 += tmp0 - MULTIPLY(z3, FIX(0.077722536)); /* c2-c4-c6 */ 520 tmp12 += tmp0 - MULTIPLY(z1, FIX(2.470602249)); /* c2+c4+c6 */ 521 tmp13 += MULTIPLY(z2, FIX(1.414213562)); /* c0 */ 522 523 /* Odd part */ 524 525 z1 = (INT32) wsptr[1]; 526 z2 = (INT32) wsptr[3]; 527 z3 = (INT32) wsptr[5]; 528 529 tmp1 = MULTIPLY(z1 + z2, FIX(0.935414347)); /* (c3+c1-c5)/2 */ 530 tmp2 = MULTIPLY(z1 - z2, FIX(0.170262339)); /* (c3+c5-c1)/2 */ 531 tmp0 = tmp1 - tmp2; 532 tmp1 += tmp2; 533 tmp2 = MULTIPLY(z2 + z3, - FIX(1.378756276)); /* -c1 */ 534 tmp1 += tmp2; 535 z2 = MULTIPLY(z1 + z3, FIX(0.613604268)); /* c5 */ 536 tmp0 += z2; 537 tmp2 += z2 + MULTIPLY(z3, FIX(1.870828693)); /* c3+c1-c5 */ 538 539 /* Final output stage */ 540 541 outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp10 + tmp0, 542 CONST_BITS+PASS1_BITS+3) 543 & RANGE_MASK]; 544 outptr[6] = range_limit[(int) RIGHT_SHIFT(tmp10 - tmp0, 545 CONST_BITS+PASS1_BITS+3) 546 & RANGE_MASK]; 547 outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp11 + tmp1, 548 CONST_BITS+PASS1_BITS+3) 549 & RANGE_MASK]; 550 outptr[5] = range_limit[(int) RIGHT_SHIFT(tmp11 - tmp1, 551 CONST_BITS+PASS1_BITS+3) 552 & RANGE_MASK]; 553 outptr[2] = range_limit[(int) RIGHT_SHIFT(tmp12 + tmp2, 554 CONST_BITS+PASS1_BITS+3) 555 & RANGE_MASK]; 556 outptr[4] = range_limit[(int) RIGHT_SHIFT(tmp12 - tmp2, 557 CONST_BITS+PASS1_BITS+3) 558 & RANGE_MASK]; 559 outptr[3] = range_limit[(int) RIGHT_SHIFT(tmp13, 560 CONST_BITS+PASS1_BITS+3) 561 & RANGE_MASK]; 562 563 wsptr += 7; /* advance pointer to next row */ 564 } 565 } 566 567 568 /* 569 * Perform dequantization and inverse DCT on one block of coefficients, 570 * producing a reduced-size 6x6 output block. 571 * 572 * Optimized algorithm with 3 multiplications in the 1-D kernel. 573 * cK represents sqrt(2) * cos(K*pi/12). 574 */ 575 576 GLOBAL(void) 577 jpeg_idct_6x6 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 578 JCOEFPTR coef_block, 579 JSAMPARRAY output_buf, JDIMENSION output_col) 580 { 581 INT32 tmp0, tmp1, tmp2, tmp10, tmp11, tmp12; 582 INT32 z1, z2, z3; 583 JCOEFPTR inptr; 584 ISLOW_MULT_TYPE * quantptr; 585 int * wsptr; 586 JSAMPROW outptr; 587 JSAMPLE *range_limit = IDCT_range_limit(cinfo); 588 int ctr; 589 int workspace[6*6]; /* buffers data between passes */ 590 SHIFT_TEMPS 591 592 /* Pass 1: process columns from input, store into work array. */ 593 594 inptr = coef_block; 595 quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 596 wsptr = workspace; 597 for (ctr = 0; ctr < 6; ctr++, inptr++, quantptr++, wsptr++) { 598 /* Even part */ 599 600 tmp0 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); 601 tmp0 <<= CONST_BITS; 602 /* Add fudge factor here for final descale. */ 603 tmp0 += ONE << (CONST_BITS-PASS1_BITS-1); 604 tmp2 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]); 605 tmp10 = MULTIPLY(tmp2, FIX(0.707106781)); /* c4 */ 606 tmp1 = tmp0 + tmp10; 607 tmp11 = RIGHT_SHIFT(tmp0 - tmp10 - tmp10, CONST_BITS-PASS1_BITS); 608 tmp10 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]); 609 tmp0 = MULTIPLY(tmp10, FIX(1.224744871)); /* c2 */ 610 tmp10 = tmp1 + tmp0; 611 tmp12 = tmp1 - tmp0; 612 613 /* Odd part */ 614 615 z1 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); 616 z2 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]); 617 z3 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]); 618 tmp1 = MULTIPLY(z1 + z3, FIX(0.366025404)); /* c5 */ 619 tmp0 = tmp1 + ((z1 + z2) << CONST_BITS); 620 tmp2 = tmp1 + ((z3 - z2) << CONST_BITS); 621 tmp1 = (z1 - z2 - z3) << PASS1_BITS; 622 623 /* Final output stage */ 624 625 wsptr[6*0] = (int) RIGHT_SHIFT(tmp10 + tmp0, CONST_BITS-PASS1_BITS); 626 wsptr[6*5] = (int) RIGHT_SHIFT(tmp10 - tmp0, CONST_BITS-PASS1_BITS); 627 wsptr[6*1] = (int) (tmp11 + tmp1); 628 wsptr[6*4] = (int) (tmp11 - tmp1); 629 wsptr[6*2] = (int) RIGHT_SHIFT(tmp12 + tmp2, CONST_BITS-PASS1_BITS); 630 wsptr[6*3] = (int) RIGHT_SHIFT(tmp12 - tmp2, CONST_BITS-PASS1_BITS); 631 } 632 633 /* Pass 2: process 6 rows from work array, store into output array. */ 634 635 wsptr = workspace; 636 for (ctr = 0; ctr < 6; ctr++) { 637 outptr = output_buf[ctr] + output_col; 638 639 /* Even part */ 640 641 /* Add fudge factor here for final descale. */ 642 tmp0 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2)); 643 tmp0 <<= CONST_BITS; 644 tmp2 = (INT32) wsptr[4]; 645 tmp10 = MULTIPLY(tmp2, FIX(0.707106781)); /* c4 */ 646 tmp1 = tmp0 + tmp10; 647 tmp11 = tmp0 - tmp10 - tmp10; 648 tmp10 = (INT32) wsptr[2]; 649 tmp0 = MULTIPLY(tmp10, FIX(1.224744871)); /* c2 */ 650 tmp10 = tmp1 + tmp0; 651 tmp12 = tmp1 - tmp0; 652 653 /* Odd part */ 654 655 z1 = (INT32) wsptr[1]; 656 z2 = (INT32) wsptr[3]; 657 z3 = (INT32) wsptr[5]; 658 tmp1 = MULTIPLY(z1 + z3, FIX(0.366025404)); /* c5 */ 659 tmp0 = tmp1 + ((z1 + z2) << CONST_BITS); 660 tmp2 = tmp1 + ((z3 - z2) << CONST_BITS); 661 tmp1 = (z1 - z2 - z3) << CONST_BITS; 662 663 /* Final output stage */ 664 665 outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp10 + tmp0, 666 CONST_BITS+PASS1_BITS+3) 667 & RANGE_MASK]; 668 outptr[5] = range_limit[(int) RIGHT_SHIFT(tmp10 - tmp0, 669 CONST_BITS+PASS1_BITS+3) 670 & RANGE_MASK]; 671 outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp11 + tmp1, 672 CONST_BITS+PASS1_BITS+3) 673 & RANGE_MASK]; 674 outptr[4] = range_limit[(int) RIGHT_SHIFT(tmp11 - tmp1, 675 CONST_BITS+PASS1_BITS+3) 676 & RANGE_MASK]; 677 outptr[2] = range_limit[(int) RIGHT_SHIFT(tmp12 + tmp2, 678 CONST_BITS+PASS1_BITS+3) 679 & RANGE_MASK]; 680 outptr[3] = range_limit[(int) RIGHT_SHIFT(tmp12 - tmp2, 681 CONST_BITS+PASS1_BITS+3) 682 & RANGE_MASK]; 683 684 wsptr += 6; /* advance pointer to next row */ 685 } 686 } 687 688 689 /* 690 * Perform dequantization and inverse DCT on one block of coefficients, 691 * producing a reduced-size 5x5 output block. 692 * 693 * Optimized algorithm with 5 multiplications in the 1-D kernel. 694 * cK represents sqrt(2) * cos(K*pi/10). 695 */ 696 697 GLOBAL(void) 698 jpeg_idct_5x5 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 699 JCOEFPTR coef_block, 700 JSAMPARRAY output_buf, JDIMENSION output_col) 701 { 702 INT32 tmp0, tmp1, tmp10, tmp11, tmp12; 703 INT32 z1, z2, z3; 704 JCOEFPTR inptr; 705 ISLOW_MULT_TYPE * quantptr; 706 int * wsptr; 707 JSAMPROW outptr; 708 JSAMPLE *range_limit = IDCT_range_limit(cinfo); 709 int ctr; 710 int workspace[5*5]; /* buffers data between passes */ 711 SHIFT_TEMPS 712 713 /* Pass 1: process columns from input, store into work array. */ 714 715 inptr = coef_block; 716 quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 717 wsptr = workspace; 718 for (ctr = 0; ctr < 5; ctr++, inptr++, quantptr++, wsptr++) { 719 /* Even part */ 720 721 tmp12 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); 722 tmp12 <<= CONST_BITS; 723 /* Add fudge factor here for final descale. */ 724 tmp12 += ONE << (CONST_BITS-PASS1_BITS-1); 725 tmp0 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]); 726 tmp1 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]); 727 z1 = MULTIPLY(tmp0 + tmp1, FIX(0.790569415)); /* (c2+c4)/2 */ 728 z2 = MULTIPLY(tmp0 - tmp1, FIX(0.353553391)); /* (c2-c4)/2 */ 729 z3 = tmp12 + z2; 730 tmp10 = z3 + z1; 731 tmp11 = z3 - z1; 732 tmp12 -= z2 << 2; 733 734 /* Odd part */ 735 736 z2 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); 737 z3 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]); 738 739 z1 = MULTIPLY(z2 + z3, FIX(0.831253876)); /* c3 */ 740 tmp0 = z1 + MULTIPLY(z2, FIX(0.513743148)); /* c1-c3 */ 741 tmp1 = z1 - MULTIPLY(z3, FIX(2.176250899)); /* c1+c3 */ 742 743 /* Final output stage */ 744 745 wsptr[5*0] = (int) RIGHT_SHIFT(tmp10 + tmp0, CONST_BITS-PASS1_BITS); 746 wsptr[5*4] = (int) RIGHT_SHIFT(tmp10 - tmp0, CONST_BITS-PASS1_BITS); 747 wsptr[5*1] = (int) RIGHT_SHIFT(tmp11 + tmp1, CONST_BITS-PASS1_BITS); 748 wsptr[5*3] = (int) RIGHT_SHIFT(tmp11 - tmp1, CONST_BITS-PASS1_BITS); 749 wsptr[5*2] = (int) RIGHT_SHIFT(tmp12, CONST_BITS-PASS1_BITS); 750 } 751 752 /* Pass 2: process 5 rows from work array, store into output array. */ 753 754 wsptr = workspace; 755 for (ctr = 0; ctr < 5; ctr++) { 756 outptr = output_buf[ctr] + output_col; 757 758 /* Even part */ 759 760 /* Add fudge factor here for final descale. */ 761 tmp12 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2)); 762 tmp12 <<= CONST_BITS; 763 tmp0 = (INT32) wsptr[2]; 764 tmp1 = (INT32) wsptr[4]; 765 z1 = MULTIPLY(tmp0 + tmp1, FIX(0.790569415)); /* (c2+c4)/2 */ 766 z2 = MULTIPLY(tmp0 - tmp1, FIX(0.353553391)); /* (c2-c4)/2 */ 767 z3 = tmp12 + z2; 768 tmp10 = z3 + z1; 769 tmp11 = z3 - z1; 770 tmp12 -= z2 << 2; 771 772 /* Odd part */ 773 774 z2 = (INT32) wsptr[1]; 775 z3 = (INT32) wsptr[3]; 776 777 z1 = MULTIPLY(z2 + z3, FIX(0.831253876)); /* c3 */ 778 tmp0 = z1 + MULTIPLY(z2, FIX(0.513743148)); /* c1-c3 */ 779 tmp1 = z1 - MULTIPLY(z3, FIX(2.176250899)); /* c1+c3 */ 780 781 /* Final output stage */ 782 783 outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp10 + tmp0, 784 CONST_BITS+PASS1_BITS+3) 785 & RANGE_MASK]; 786 outptr[4] = range_limit[(int) RIGHT_SHIFT(tmp10 - tmp0, 787 CONST_BITS+PASS1_BITS+3) 788 & RANGE_MASK]; 789 outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp11 + tmp1, 790 CONST_BITS+PASS1_BITS+3) 791 & RANGE_MASK]; 792 outptr[3] = range_limit[(int) RIGHT_SHIFT(tmp11 - tmp1, 793 CONST_BITS+PASS1_BITS+3) 794 & RANGE_MASK]; 795 outptr[2] = range_limit[(int) RIGHT_SHIFT(tmp12, 796 CONST_BITS+PASS1_BITS+3) 797 & RANGE_MASK]; 798 799 wsptr += 5; /* advance pointer to next row */ 800 } 801 } 802 803 804 /* 805 * Perform dequantization and inverse DCT on one block of coefficients, 806 * producing a reduced-size 4x4 output block. 807 * 808 * Optimized algorithm with 3 multiplications in the 1-D kernel. 809 * cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point IDCT]. 810 */ 811 812 GLOBAL(void) 813 jpeg_idct_4x4 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 814 JCOEFPTR coef_block, 815 JSAMPARRAY output_buf, JDIMENSION output_col) 816 { 817 INT32 tmp0, tmp2, tmp10, tmp12; 818 INT32 z1, z2, z3; 819 JCOEFPTR inptr; 820 ISLOW_MULT_TYPE * quantptr; 821 int * wsptr; 822 JSAMPROW outptr; 823 JSAMPLE *range_limit = IDCT_range_limit(cinfo); 824 int ctr; 825 int workspace[4*4]; /* buffers data between passes */ 826 SHIFT_TEMPS 827 828 /* Pass 1: process columns from input, store into work array. */ 829 830 inptr = coef_block; 831 quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 832 wsptr = workspace; 833 for (ctr = 0; ctr < 4; ctr++, inptr++, quantptr++, wsptr++) { 834 /* Even part */ 835 836 tmp0 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); 837 tmp2 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]); 838 839 tmp10 = (tmp0 + tmp2) << PASS1_BITS; 840 tmp12 = (tmp0 - tmp2) << PASS1_BITS; 841 842 /* Odd part */ 843 /* Same rotation as in the even part of the 8x8 LL&M IDCT */ 844 845 z2 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); 846 z3 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]); 847 848 z1 = MULTIPLY(z2 + z3, FIX_0_541196100); /* c6 */ 849 /* Add fudge factor here for final descale. */ 850 z1 += ONE << (CONST_BITS-PASS1_BITS-1); 851 tmp0 = RIGHT_SHIFT(z1 + MULTIPLY(z2, FIX_0_765366865), /* c2-c6 */ 852 CONST_BITS-PASS1_BITS); 853 tmp2 = RIGHT_SHIFT(z1 - MULTIPLY(z3, FIX_1_847759065), /* c2+c6 */ 854 CONST_BITS-PASS1_BITS); 855 856 /* Final output stage */ 857 858 wsptr[4*0] = (int) (tmp10 + tmp0); 859 wsptr[4*3] = (int) (tmp10 - tmp0); 860 wsptr[4*1] = (int) (tmp12 + tmp2); 861 wsptr[4*2] = (int) (tmp12 - tmp2); 862 } 863 864 /* Pass 2: process 4 rows from work array, store into output array. */ 865 866 wsptr = workspace; 867 for (ctr = 0; ctr < 4; ctr++) { 868 outptr = output_buf[ctr] + output_col; 869 870 /* Even part */ 871 872 /* Add fudge factor here for final descale. */ 873 tmp0 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2)); 874 tmp2 = (INT32) wsptr[2]; 875 876 tmp10 = (tmp0 + tmp2) << CONST_BITS; 877 tmp12 = (tmp0 - tmp2) << CONST_BITS; 878 879 /* Odd part */ 880 /* Same rotation as in the even part of the 8x8 LL&M IDCT */ 881 882 z2 = (INT32) wsptr[1]; 883 z3 = (INT32) wsptr[3]; 884 885 z1 = MULTIPLY(z2 + z3, FIX_0_541196100); /* c6 */ 886 tmp0 = z1 + MULTIPLY(z2, FIX_0_765366865); /* c2-c6 */ 887 tmp2 = z1 - MULTIPLY(z3, FIX_1_847759065); /* c2+c6 */ 888 889 /* Final output stage */ 890 891 outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp10 + tmp0, 892 CONST_BITS+PASS1_BITS+3) 893 & RANGE_MASK]; 894 outptr[3] = range_limit[(int) RIGHT_SHIFT(tmp10 - tmp0, 895 CONST_BITS+PASS1_BITS+3) 896 & RANGE_MASK]; 897 outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp12 + tmp2, 898 CONST_BITS+PASS1_BITS+3) 899 & RANGE_MASK]; 900 outptr[2] = range_limit[(int) RIGHT_SHIFT(tmp12 - tmp2, 901 CONST_BITS+PASS1_BITS+3) 902 & RANGE_MASK]; 903 904 wsptr += 4; /* advance pointer to next row */ 905 } 906 } 907 908 909 /* 910 * Perform dequantization and inverse DCT on one block of coefficients, 911 * producing a reduced-size 3x3 output block. 912 * 913 * Optimized algorithm with 2 multiplications in the 1-D kernel. 914 * cK represents sqrt(2) * cos(K*pi/6). 915 */ 916 917 GLOBAL(void) 918 jpeg_idct_3x3 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 919 JCOEFPTR coef_block, 920 JSAMPARRAY output_buf, JDIMENSION output_col) 921 { 922 INT32 tmp0, tmp2, tmp10, tmp12; 923 JCOEFPTR inptr; 924 ISLOW_MULT_TYPE * quantptr; 925 int * wsptr; 926 JSAMPROW outptr; 927 JSAMPLE *range_limit = IDCT_range_limit(cinfo); 928 int ctr; 929 int workspace[3*3]; /* buffers data between passes */ 930 SHIFT_TEMPS 931 932 /* Pass 1: process columns from input, store into work array. */ 933 934 inptr = coef_block; 935 quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 936 wsptr = workspace; 937 for (ctr = 0; ctr < 3; ctr++, inptr++, quantptr++, wsptr++) { 938 /* Even part */ 939 940 tmp0 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); 941 tmp0 <<= CONST_BITS; 942 /* Add fudge factor here for final descale. */ 943 tmp0 += ONE << (CONST_BITS-PASS1_BITS-1); 944 tmp2 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]); 945 tmp12 = MULTIPLY(tmp2, FIX(0.707106781)); /* c2 */ 946 tmp10 = tmp0 + tmp12; 947 tmp2 = tmp0 - tmp12 - tmp12; 948 949 /* Odd part */ 950 951 tmp12 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); 952 tmp0 = MULTIPLY(tmp12, FIX(1.224744871)); /* c1 */ 953 954 /* Final output stage */ 955 956 wsptr[3*0] = (int) RIGHT_SHIFT(tmp10 + tmp0, CONST_BITS-PASS1_BITS); 957 wsptr[3*2] = (int) RIGHT_SHIFT(tmp10 - tmp0, CONST_BITS-PASS1_BITS); 958 wsptr[3*1] = (int) RIGHT_SHIFT(tmp2, CONST_BITS-PASS1_BITS); 959 } 960 961 /* Pass 2: process 3 rows from work array, store into output array. */ 962 963 wsptr = workspace; 964 for (ctr = 0; ctr < 3; ctr++) { 965 outptr = output_buf[ctr] + output_col; 966 967 /* Even part */ 968 969 /* Add fudge factor here for final descale. */ 970 tmp0 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2)); 971 tmp0 <<= CONST_BITS; 972 tmp2 = (INT32) wsptr[2]; 973 tmp12 = MULTIPLY(tmp2, FIX(0.707106781)); /* c2 */ 974 tmp10 = tmp0 + tmp12; 975 tmp2 = tmp0 - tmp12 - tmp12; 976 977 /* Odd part */ 978 979 tmp12 = (INT32) wsptr[1]; 980 tmp0 = MULTIPLY(tmp12, FIX(1.224744871)); /* c1 */ 981 982 /* Final output stage */ 983 984 outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp10 + tmp0, 985 CONST_BITS+PASS1_BITS+3) 986 & RANGE_MASK]; 987 outptr[2] = range_limit[(int) RIGHT_SHIFT(tmp10 - tmp0, 988 CONST_BITS+PASS1_BITS+3) 989 & RANGE_MASK]; 990 outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp2, 991 CONST_BITS+PASS1_BITS+3) 992 & RANGE_MASK]; 993 994 wsptr += 3; /* advance pointer to next row */ 995 } 996 } 997 998 999 /* 1000 * Perform dequantization and inverse DCT on one block of coefficients, 1001 * producing a reduced-size 2x2 output block. 1002 * 1003 * Multiplication-less algorithm. 1004 */ 1005 1006 GLOBAL(void) 1007 jpeg_idct_2x2 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 1008 JCOEFPTR coef_block, 1009 JSAMPARRAY output_buf, JDIMENSION output_col) 1010 { 1011 INT32 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5; 1012 ISLOW_MULT_TYPE * quantptr; 1013 JSAMPROW outptr; 1014 JSAMPLE *range_limit = IDCT_range_limit(cinfo); 1015 SHIFT_TEMPS 1016 1017 /* Pass 1: process columns from input. */ 1018 1019 quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 1020 1021 /* Column 0 */ 1022 tmp4 = DEQUANTIZE(coef_block[DCTSIZE*0], quantptr[DCTSIZE*0]); 1023 tmp5 = DEQUANTIZE(coef_block[DCTSIZE*1], quantptr[DCTSIZE*1]); 1024 /* Add fudge factor here for final descale. */ 1025 tmp4 += ONE << 2; 1026 1027 tmp0 = tmp4 + tmp5; 1028 tmp2 = tmp4 - tmp5; 1029 1030 /* Column 1 */ 1031 tmp4 = DEQUANTIZE(coef_block[DCTSIZE*0+1], quantptr[DCTSIZE*0+1]); 1032 tmp5 = DEQUANTIZE(coef_block[DCTSIZE*1+1], quantptr[DCTSIZE*1+1]); 1033 1034 tmp1 = tmp4 + tmp5; 1035 tmp3 = tmp4 - tmp5; 1036 1037 /* Pass 2: process 2 rows, store into output array. */ 1038 1039 /* Row 0 */ 1040 outptr = output_buf[0] + output_col; 1041 1042 outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp0 + tmp1, 3) & RANGE_MASK]; 1043 outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp0 - tmp1, 3) & RANGE_MASK]; 1044 1045 /* Row 1 */ 1046 outptr = output_buf[1] + output_col; 1047 1048 outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp2 + tmp3, 3) & RANGE_MASK]; 1049 outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp2 - tmp3, 3) & RANGE_MASK]; 1050 } 1051 1052 1053 /* 1054 * Perform dequantization and inverse DCT on one block of coefficients, 1055 * producing a reduced-size 1x1 output block. 1056 * 1057 * We hardly need an inverse DCT routine for this: just take the 1058 * average pixel value, which is one-eighth of the DC coefficient. 1059 */ 1060 1061 GLOBAL(void) 1062 jpeg_idct_1x1 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 1063 JCOEFPTR coef_block, 1064 JSAMPARRAY output_buf, JDIMENSION output_col) 1065 { 1066 int dcval; 1067 ISLOW_MULT_TYPE * quantptr; 1068 JSAMPLE *range_limit = IDCT_range_limit(cinfo); 1069 SHIFT_TEMPS 1070 1071 /* 1x1 is trivial: just take the DC coefficient divided by 8. */ 1072 quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 1073 dcval = DEQUANTIZE(coef_block[0], quantptr[0]); 1074 dcval = (int) DESCALE((INT32) dcval, 3); 1075 1076 output_buf[0][output_col] = range_limit[dcval & RANGE_MASK]; 1077 } 1078 1079 1080 /* 1081 * Perform dequantization and inverse DCT on one block of coefficients, 1082 * producing a 9x9 output block. 1083 * 1084 * Optimized algorithm with 10 multiplications in the 1-D kernel. 1085 * cK represents sqrt(2) * cos(K*pi/18). 1086 */ 1087 1088 GLOBAL(void) 1089 jpeg_idct_9x9 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 1090 JCOEFPTR coef_block, 1091 JSAMPARRAY output_buf, JDIMENSION output_col) 1092 { 1093 INT32 tmp0, tmp1, tmp2, tmp3, tmp10, tmp11, tmp12, tmp13, tmp14; 1094 INT32 z1, z2, z3, z4; 1095 JCOEFPTR inptr; 1096 ISLOW_MULT_TYPE * quantptr; 1097 int * wsptr; 1098 JSAMPROW outptr; 1099 JSAMPLE *range_limit = IDCT_range_limit(cinfo); 1100 int ctr; 1101 int workspace[8*9]; /* buffers data between passes */ 1102 SHIFT_TEMPS 1103 1104 /* Pass 1: process columns from input, store into work array. */ 1105 1106 inptr = coef_block; 1107 quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 1108 wsptr = workspace; 1109 for (ctr = 0; ctr < 8; ctr++, inptr++, quantptr++, wsptr++) { 1110 /* Even part */ 1111 1112 tmp0 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); 1113 tmp0 <<= CONST_BITS; 1114 /* Add fudge factor here for final descale. */ 1115 tmp0 += ONE << (CONST_BITS-PASS1_BITS-1); 1116 1117 z1 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]); 1118 z2 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]); 1119 z3 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]); 1120 1121 tmp3 = MULTIPLY(z3, FIX(0.707106781)); /* c6 */ 1122 tmp1 = tmp0 + tmp3; 1123 tmp2 = tmp0 - tmp3 - tmp3; 1124 1125 tmp0 = MULTIPLY(z1 - z2, FIX(0.707106781)); /* c6 */ 1126 tmp11 = tmp2 + tmp0; 1127 tmp14 = tmp2 - tmp0 - tmp0; 1128 1129 tmp0 = MULTIPLY(z1 + z2, FIX(1.328926049)); /* c2 */ 1130 tmp2 = MULTIPLY(z1, FIX(1.083350441)); /* c4 */ 1131 tmp3 = MULTIPLY(z2, FIX(0.245575608)); /* c8 */ 1132 1133 tmp10 = tmp1 + tmp0 - tmp3; 1134 tmp12 = tmp1 - tmp0 + tmp2; 1135 tmp13 = tmp1 - tmp2 + tmp3; 1136 1137 /* Odd part */ 1138 1139 z1 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); 1140 z2 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]); 1141 z3 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]); 1142 z4 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]); 1143 1144 z2 = MULTIPLY(z2, - FIX(1.224744871)); /* -c3 */ 1145 1146 tmp2 = MULTIPLY(z1 + z3, FIX(0.909038955)); /* c5 */ 1147 tmp3 = MULTIPLY(z1 + z4, FIX(0.483689525)); /* c7 */ 1148 tmp0 = tmp2 + tmp3 - z2; 1149 tmp1 = MULTIPLY(z3 - z4, FIX(1.392728481)); /* c1 */ 1150 tmp2 += z2 - tmp1; 1151 tmp3 += z2 + tmp1; 1152 tmp1 = MULTIPLY(z1 - z3 - z4, FIX(1.224744871)); /* c3 */ 1153 1154 /* Final output stage */ 1155 1156 wsptr[8*0] = (int) RIGHT_SHIFT(tmp10 + tmp0, CONST_BITS-PASS1_BITS); 1157 wsptr[8*8] = (int) RIGHT_SHIFT(tmp10 - tmp0, CONST_BITS-PASS1_BITS); 1158 wsptr[8*1] = (int) RIGHT_SHIFT(tmp11 + tmp1, CONST_BITS-PASS1_BITS); 1159 wsptr[8*7] = (int) RIGHT_SHIFT(tmp11 - tmp1, CONST_BITS-PASS1_BITS); 1160 wsptr[8*2] = (int) RIGHT_SHIFT(tmp12 + tmp2, CONST_BITS-PASS1_BITS); 1161 wsptr[8*6] = (int) RIGHT_SHIFT(tmp12 - tmp2, CONST_BITS-PASS1_BITS); 1162 wsptr[8*3] = (int) RIGHT_SHIFT(tmp13 + tmp3, CONST_BITS-PASS1_BITS); 1163 wsptr[8*5] = (int) RIGHT_SHIFT(tmp13 - tmp3, CONST_BITS-PASS1_BITS); 1164 wsptr[8*4] = (int) RIGHT_SHIFT(tmp14, CONST_BITS-PASS1_BITS); 1165 } 1166 1167 /* Pass 2: process 9 rows from work array, store into output array. */ 1168 1169 wsptr = workspace; 1170 for (ctr = 0; ctr < 9; ctr++) { 1171 outptr = output_buf[ctr] + output_col; 1172 1173 /* Even part */ 1174 1175 /* Add fudge factor here for final descale. */ 1176 tmp0 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2)); 1177 tmp0 <<= CONST_BITS; 1178 1179 z1 = (INT32) wsptr[2]; 1180 z2 = (INT32) wsptr[4]; 1181 z3 = (INT32) wsptr[6]; 1182 1183 tmp3 = MULTIPLY(z3, FIX(0.707106781)); /* c6 */ 1184 tmp1 = tmp0 + tmp3; 1185 tmp2 = tmp0 - tmp3 - tmp3; 1186 1187 tmp0 = MULTIPLY(z1 - z2, FIX(0.707106781)); /* c6 */ 1188 tmp11 = tmp2 + tmp0; 1189 tmp14 = tmp2 - tmp0 - tmp0; 1190 1191 tmp0 = MULTIPLY(z1 + z2, FIX(1.328926049)); /* c2 */ 1192 tmp2 = MULTIPLY(z1, FIX(1.083350441)); /* c4 */ 1193 tmp3 = MULTIPLY(z2, FIX(0.245575608)); /* c8 */ 1194 1195 tmp10 = tmp1 + tmp0 - tmp3; 1196 tmp12 = tmp1 - tmp0 + tmp2; 1197 tmp13 = tmp1 - tmp2 + tmp3; 1198 1199 /* Odd part */ 1200 1201 z1 = (INT32) wsptr[1]; 1202 z2 = (INT32) wsptr[3]; 1203 z3 = (INT32) wsptr[5]; 1204 z4 = (INT32) wsptr[7]; 1205 1206 z2 = MULTIPLY(z2, - FIX(1.224744871)); /* -c3 */ 1207 1208 tmp2 = MULTIPLY(z1 + z3, FIX(0.909038955)); /* c5 */ 1209 tmp3 = MULTIPLY(z1 + z4, FIX(0.483689525)); /* c7 */ 1210 tmp0 = tmp2 + tmp3 - z2; 1211 tmp1 = MULTIPLY(z3 - z4, FIX(1.392728481)); /* c1 */ 1212 tmp2 += z2 - tmp1; 1213 tmp3 += z2 + tmp1; 1214 tmp1 = MULTIPLY(z1 - z3 - z4, FIX(1.224744871)); /* c3 */ 1215 1216 /* Final output stage */ 1217 1218 outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp10 + tmp0, 1219 CONST_BITS+PASS1_BITS+3) 1220 & RANGE_MASK]; 1221 outptr[8] = range_limit[(int) RIGHT_SHIFT(tmp10 - tmp0, 1222 CONST_BITS+PASS1_BITS+3) 1223 & RANGE_MASK]; 1224 outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp11 + tmp1, 1225 CONST_BITS+PASS1_BITS+3) 1226 & RANGE_MASK]; 1227 outptr[7] = range_limit[(int) RIGHT_SHIFT(tmp11 - tmp1, 1228 CONST_BITS+PASS1_BITS+3) 1229 & RANGE_MASK]; 1230 outptr[2] = range_limit[(int) RIGHT_SHIFT(tmp12 + tmp2, 1231 CONST_BITS+PASS1_BITS+3) 1232 & RANGE_MASK]; 1233 outptr[6] = range_limit[(int) RIGHT_SHIFT(tmp12 - tmp2, 1234 CONST_BITS+PASS1_BITS+3) 1235 & RANGE_MASK]; 1236 outptr[3] = range_limit[(int) RIGHT_SHIFT(tmp13 + tmp3, 1237 CONST_BITS+PASS1_BITS+3) 1238 & RANGE_MASK]; 1239 outptr[5] = range_limit[(int) RIGHT_SHIFT(tmp13 - tmp3, 1240 CONST_BITS+PASS1_BITS+3) 1241 & RANGE_MASK]; 1242 outptr[4] = range_limit[(int) RIGHT_SHIFT(tmp14, 1243 CONST_BITS+PASS1_BITS+3) 1244 & RANGE_MASK]; 1245 1246 wsptr += 8; /* advance pointer to next row */ 1247 } 1248 } 1249 1250 1251 /* 1252 * Perform dequantization and inverse DCT on one block of coefficients, 1253 * producing a 10x10 output block. 1254 * 1255 * Optimized algorithm with 12 multiplications in the 1-D kernel. 1256 * cK represents sqrt(2) * cos(K*pi/20). 1257 */ 1258 1259 GLOBAL(void) 1260 jpeg_idct_10x10 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 1261 JCOEFPTR coef_block, 1262 JSAMPARRAY output_buf, JDIMENSION output_col) 1263 { 1264 INT32 tmp10, tmp11, tmp12, tmp13, tmp14; 1265 INT32 tmp20, tmp21, tmp22, tmp23, tmp24; 1266 INT32 z1, z2, z3, z4, z5; 1267 JCOEFPTR inptr; 1268 ISLOW_MULT_TYPE * quantptr; 1269 int * wsptr; 1270 JSAMPROW outptr; 1271 JSAMPLE *range_limit = IDCT_range_limit(cinfo); 1272 int ctr; 1273 int workspace[8*10]; /* buffers data between passes */ 1274 SHIFT_TEMPS 1275 1276 /* Pass 1: process columns from input, store into work array. */ 1277 1278 inptr = coef_block; 1279 quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 1280 wsptr = workspace; 1281 for (ctr = 0; ctr < 8; ctr++, inptr++, quantptr++, wsptr++) { 1282 /* Even part */ 1283 1284 z3 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); 1285 z3 <<= CONST_BITS; 1286 /* Add fudge factor here for final descale. */ 1287 z3 += ONE << (CONST_BITS-PASS1_BITS-1); 1288 z4 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]); 1289 z1 = MULTIPLY(z4, FIX(1.144122806)); /* c4 */ 1290 z2 = MULTIPLY(z4, FIX(0.437016024)); /* c8 */ 1291 tmp10 = z3 + z1; 1292 tmp11 = z3 - z2; 1293 1294 tmp22 = RIGHT_SHIFT(z3 - ((z1 - z2) << 1), /* c0 = (c4-c8)*2 */ 1295 CONST_BITS-PASS1_BITS); 1296 1297 z2 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]); 1298 z3 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]); 1299 1300 z1 = MULTIPLY(z2 + z3, FIX(0.831253876)); /* c6 */ 1301 tmp12 = z1 + MULTIPLY(z2, FIX(0.513743148)); /* c2-c6 */ 1302 tmp13 = z1 - MULTIPLY(z3, FIX(2.176250899)); /* c2+c6 */ 1303 1304 tmp20 = tmp10 + tmp12; 1305 tmp24 = tmp10 - tmp12; 1306 tmp21 = tmp11 + tmp13; 1307 tmp23 = tmp11 - tmp13; 1308 1309 /* Odd part */ 1310 1311 z1 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); 1312 z2 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]); 1313 z3 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]); 1314 z4 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]); 1315 1316 tmp11 = z2 + z4; 1317 tmp13 = z2 - z4; 1318 1319 tmp12 = MULTIPLY(tmp13, FIX(0.309016994)); /* (c3-c7)/2 */ 1320 z5 = z3 << CONST_BITS; 1321 1322 z2 = MULTIPLY(tmp11, FIX(0.951056516)); /* (c3+c7)/2 */ 1323 z4 = z5 + tmp12; 1324 1325 tmp10 = MULTIPLY(z1, FIX(1.396802247)) + z2 + z4; /* c1 */ 1326 tmp14 = MULTIPLY(z1, FIX(0.221231742)) - z2 + z4; /* c9 */ 1327 1328 z2 = MULTIPLY(tmp11, FIX(0.587785252)); /* (c1-c9)/2 */ 1329 z4 = z5 - tmp12 - (tmp13 << (CONST_BITS - 1)); 1330 1331 tmp12 = (z1 - tmp13 - z3) << PASS1_BITS; 1332 1333 tmp11 = MULTIPLY(z1, FIX(1.260073511)) - z2 - z4; /* c3 */ 1334 tmp13 = MULTIPLY(z1, FIX(0.642039522)) - z2 + z4; /* c7 */ 1335 1336 /* Final output stage */ 1337 1338 wsptr[8*0] = (int) RIGHT_SHIFT(tmp20 + tmp10, CONST_BITS-PASS1_BITS); 1339 wsptr[8*9] = (int) RIGHT_SHIFT(tmp20 - tmp10, CONST_BITS-PASS1_BITS); 1340 wsptr[8*1] = (int) RIGHT_SHIFT(tmp21 + tmp11, CONST_BITS-PASS1_BITS); 1341 wsptr[8*8] = (int) RIGHT_SHIFT(tmp21 - tmp11, CONST_BITS-PASS1_BITS); 1342 wsptr[8*2] = (int) (tmp22 + tmp12); 1343 wsptr[8*7] = (int) (tmp22 - tmp12); 1344 wsptr[8*3] = (int) RIGHT_SHIFT(tmp23 + tmp13, CONST_BITS-PASS1_BITS); 1345 wsptr[8*6] = (int) RIGHT_SHIFT(tmp23 - tmp13, CONST_BITS-PASS1_BITS); 1346 wsptr[8*4] = (int) RIGHT_SHIFT(tmp24 + tmp14, CONST_BITS-PASS1_BITS); 1347 wsptr[8*5] = (int) RIGHT_SHIFT(tmp24 - tmp14, CONST_BITS-PASS1_BITS); 1348 } 1349 1350 /* Pass 2: process 10 rows from work array, store into output array. */ 1351 1352 wsptr = workspace; 1353 for (ctr = 0; ctr < 10; ctr++) { 1354 outptr = output_buf[ctr] + output_col; 1355 1356 /* Even part */ 1357 1358 /* Add fudge factor here for final descale. */ 1359 z3 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2)); 1360 z3 <<= CONST_BITS; 1361 z4 = (INT32) wsptr[4]; 1362 z1 = MULTIPLY(z4, FIX(1.144122806)); /* c4 */ 1363 z2 = MULTIPLY(z4, FIX(0.437016024)); /* c8 */ 1364 tmp10 = z3 + z1; 1365 tmp11 = z3 - z2; 1366 1367 tmp22 = z3 - ((z1 - z2) << 1); /* c0 = (c4-c8)*2 */ 1368 1369 z2 = (INT32) wsptr[2]; 1370 z3 = (INT32) wsptr[6]; 1371 1372 z1 = MULTIPLY(z2 + z3, FIX(0.831253876)); /* c6 */ 1373 tmp12 = z1 + MULTIPLY(z2, FIX(0.513743148)); /* c2-c6 */ 1374 tmp13 = z1 - MULTIPLY(z3, FIX(2.176250899)); /* c2+c6 */ 1375 1376 tmp20 = tmp10 + tmp12; 1377 tmp24 = tmp10 - tmp12; 1378 tmp21 = tmp11 + tmp13; 1379 tmp23 = tmp11 - tmp13; 1380 1381 /* Odd part */ 1382 1383 z1 = (INT32) wsptr[1]; 1384 z2 = (INT32) wsptr[3]; 1385 z3 = (INT32) wsptr[5]; 1386 z3 <<= CONST_BITS; 1387 z4 = (INT32) wsptr[7]; 1388 1389 tmp11 = z2 + z4; 1390 tmp13 = z2 - z4; 1391 1392 tmp12 = MULTIPLY(tmp13, FIX(0.309016994)); /* (c3-c7)/2 */ 1393 1394 z2 = MULTIPLY(tmp11, FIX(0.951056516)); /* (c3+c7)/2 */ 1395 z4 = z3 + tmp12; 1396 1397 tmp10 = MULTIPLY(z1, FIX(1.396802247)) + z2 + z4; /* c1 */ 1398 tmp14 = MULTIPLY(z1, FIX(0.221231742)) - z2 + z4; /* c9 */ 1399 1400 z2 = MULTIPLY(tmp11, FIX(0.587785252)); /* (c1-c9)/2 */ 1401 z4 = z3 - tmp12 - (tmp13 << (CONST_BITS - 1)); 1402 1403 tmp12 = ((z1 - tmp13) << CONST_BITS) - z3; 1404 1405 tmp11 = MULTIPLY(z1, FIX(1.260073511)) - z2 - z4; /* c3 */ 1406 tmp13 = MULTIPLY(z1, FIX(0.642039522)) - z2 + z4; /* c7 */ 1407 1408 /* Final output stage */ 1409 1410 outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp20 + tmp10, 1411 CONST_BITS+PASS1_BITS+3) 1412 & RANGE_MASK]; 1413 outptr[9] = range_limit[(int) RIGHT_SHIFT(tmp20 - tmp10, 1414 CONST_BITS+PASS1_BITS+3) 1415 & RANGE_MASK]; 1416 outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp21 + tmp11, 1417 CONST_BITS+PASS1_BITS+3) 1418 & RANGE_MASK]; 1419 outptr[8] = range_limit[(int) RIGHT_SHIFT(tmp21 - tmp11, 1420 CONST_BITS+PASS1_BITS+3) 1421 & RANGE_MASK]; 1422 outptr[2] = range_limit[(int) RIGHT_SHIFT(tmp22 + tmp12, 1423 CONST_BITS+PASS1_BITS+3) 1424 & RANGE_MASK]; 1425 outptr[7] = range_limit[(int) RIGHT_SHIFT(tmp22 - tmp12, 1426 CONST_BITS+PASS1_BITS+3) 1427 & RANGE_MASK]; 1428 outptr[3] = range_limit[(int) RIGHT_SHIFT(tmp23 + tmp13, 1429 CONST_BITS+PASS1_BITS+3) 1430 & RANGE_MASK]; 1431 outptr[6] = range_limit[(int) RIGHT_SHIFT(tmp23 - tmp13, 1432 CONST_BITS+PASS1_BITS+3) 1433 & RANGE_MASK]; 1434 outptr[4] = range_limit[(int) RIGHT_SHIFT(tmp24 + tmp14, 1435 CONST_BITS+PASS1_BITS+3) 1436 & RANGE_MASK]; 1437 outptr[5] = range_limit[(int) RIGHT_SHIFT(tmp24 - tmp14, 1438 CONST_BITS+PASS1_BITS+3) 1439 & RANGE_MASK]; 1440 1441 wsptr += 8; /* advance pointer to next row */ 1442 } 1443 } 1444 1445 1446 /* 1447 * Perform dequantization and inverse DCT on one block of coefficients, 1448 * producing a 11x11 output block. 1449 * 1450 * Optimized algorithm with 24 multiplications in the 1-D kernel. 1451 * cK represents sqrt(2) * cos(K*pi/22). 1452 */ 1453 1454 GLOBAL(void) 1455 jpeg_idct_11x11 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 1456 JCOEFPTR coef_block, 1457 JSAMPARRAY output_buf, JDIMENSION output_col) 1458 { 1459 INT32 tmp10, tmp11, tmp12, tmp13, tmp14; 1460 INT32 tmp20, tmp21, tmp22, tmp23, tmp24, tmp25; 1461 INT32 z1, z2, z3, z4; 1462 JCOEFPTR inptr; 1463 ISLOW_MULT_TYPE * quantptr; 1464 int * wsptr; 1465 JSAMPROW outptr; 1466 JSAMPLE *range_limit = IDCT_range_limit(cinfo); 1467 int ctr; 1468 int workspace[8*11]; /* buffers data between passes */ 1469 SHIFT_TEMPS 1470 1471 /* Pass 1: process columns from input, store into work array. */ 1472 1473 inptr = coef_block; 1474 quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 1475 wsptr = workspace; 1476 for (ctr = 0; ctr < 8; ctr++, inptr++, quantptr++, wsptr++) { 1477 /* Even part */ 1478 1479 tmp10 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); 1480 tmp10 <<= CONST_BITS; 1481 /* Add fudge factor here for final descale. */ 1482 tmp10 += ONE << (CONST_BITS-PASS1_BITS-1); 1483 1484 z1 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]); 1485 z2 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]); 1486 z3 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]); 1487 1488 tmp20 = MULTIPLY(z2 - z3, FIX(2.546640132)); /* c2+c4 */ 1489 tmp23 = MULTIPLY(z2 - z1, FIX(0.430815045)); /* c2-c6 */ 1490 z4 = z1 + z3; 1491 tmp24 = MULTIPLY(z4, - FIX(1.155664402)); /* -(c2-c10) */ 1492 z4 -= z2; 1493 tmp25 = tmp10 + MULTIPLY(z4, FIX(1.356927976)); /* c2 */ 1494 tmp21 = tmp20 + tmp23 + tmp25 - 1495 MULTIPLY(z2, FIX(1.821790775)); /* c2+c4+c10-c6 */ 1496 tmp20 += tmp25 + MULTIPLY(z3, FIX(2.115825087)); /* c4+c6 */ 1497 tmp23 += tmp25 - MULTIPLY(z1, FIX(1.513598477)); /* c6+c8 */ 1498 tmp24 += tmp25; 1499 tmp22 = tmp24 - MULTIPLY(z3, FIX(0.788749120)); /* c8+c10 */ 1500 tmp24 += MULTIPLY(z2, FIX(1.944413522)) - /* c2+c8 */ 1501 MULTIPLY(z1, FIX(1.390975730)); /* c4+c10 */ 1502 tmp25 = tmp10 - MULTIPLY(z4, FIX(1.414213562)); /* c0 */ 1503 1504 /* Odd part */ 1505 1506 z1 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); 1507 z2 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]); 1508 z3 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]); 1509 z4 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]); 1510 1511 tmp11 = z1 + z2; 1512 tmp14 = MULTIPLY(tmp11 + z3 + z4, FIX(0.398430003)); /* c9 */ 1513 tmp11 = MULTIPLY(tmp11, FIX(0.887983902)); /* c3-c9 */ 1514 tmp12 = MULTIPLY(z1 + z3, FIX(0.670361295)); /* c5-c9 */ 1515 tmp13 = tmp14 + MULTIPLY(z1 + z4, FIX(0.366151574)); /* c7-c9 */ 1516 tmp10 = tmp11 + tmp12 + tmp13 - 1517 MULTIPLY(z1, FIX(0.923107866)); /* c7+c5+c3-c1-2*c9 */ 1518 z1 = tmp14 - MULTIPLY(z2 + z3, FIX(1.163011579)); /* c7+c9 */ 1519 tmp11 += z1 + MULTIPLY(z2, FIX(2.073276588)); /* c1+c7+3*c9-c3 */ 1520 tmp12 += z1 - MULTIPLY(z3, FIX(1.192193623)); /* c3+c5-c7-c9 */ 1521 z1 = MULTIPLY(z2 + z4, - FIX(1.798248910)); /* -(c1+c9) */ 1522 tmp11 += z1; 1523 tmp13 += z1 + MULTIPLY(z4, FIX(2.102458632)); /* c1+c5+c9-c7 */ 1524 tmp14 += MULTIPLY(z2, - FIX(1.467221301)) + /* -(c5+c9) */ 1525 MULTIPLY(z3, FIX(1.001388905)) - /* c1-c9 */ 1526 MULTIPLY(z4, FIX(1.684843907)); /* c3+c9 */ 1527 1528 /* Final output stage */ 1529 1530 wsptr[8*0] = (int) RIGHT_SHIFT(tmp20 + tmp10, CONST_BITS-PASS1_BITS); 1531 wsptr[8*10] = (int) RIGHT_SHIFT(tmp20 - tmp10, CONST_BITS-PASS1_BITS); 1532 wsptr[8*1] = (int) RIGHT_SHIFT(tmp21 + tmp11, CONST_BITS-PASS1_BITS); 1533 wsptr[8*9] = (int) RIGHT_SHIFT(tmp21 - tmp11, CONST_BITS-PASS1_BITS); 1534 wsptr[8*2] = (int) RIGHT_SHIFT(tmp22 + tmp12, CONST_BITS-PASS1_BITS); 1535 wsptr[8*8] = (int) RIGHT_SHIFT(tmp22 - tmp12, CONST_BITS-PASS1_BITS); 1536 wsptr[8*3] = (int) RIGHT_SHIFT(tmp23 + tmp13, CONST_BITS-PASS1_BITS); 1537 wsptr[8*7] = (int) RIGHT_SHIFT(tmp23 - tmp13, CONST_BITS-PASS1_BITS); 1538 wsptr[8*4] = (int) RIGHT_SHIFT(tmp24 + tmp14, CONST_BITS-PASS1_BITS); 1539 wsptr[8*6] = (int) RIGHT_SHIFT(tmp24 - tmp14, CONST_BITS-PASS1_BITS); 1540 wsptr[8*5] = (int) RIGHT_SHIFT(tmp25, CONST_BITS-PASS1_BITS); 1541 } 1542 1543 /* Pass 2: process 11 rows from work array, store into output array. */ 1544 1545 wsptr = workspace; 1546 for (ctr = 0; ctr < 11; ctr++) { 1547 outptr = output_buf[ctr] + output_col; 1548 1549 /* Even part */ 1550 1551 /* Add fudge factor here for final descale. */ 1552 tmp10 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2)); 1553 tmp10 <<= CONST_BITS; 1554 1555 z1 = (INT32) wsptr[2]; 1556 z2 = (INT32) wsptr[4]; 1557 z3 = (INT32) wsptr[6]; 1558 1559 tmp20 = MULTIPLY(z2 - z3, FIX(2.546640132)); /* c2+c4 */ 1560 tmp23 = MULTIPLY(z2 - z1, FIX(0.430815045)); /* c2-c6 */ 1561 z4 = z1 + z3; 1562 tmp24 = MULTIPLY(z4, - FIX(1.155664402)); /* -(c2-c10) */ 1563 z4 -= z2; 1564 tmp25 = tmp10 + MULTIPLY(z4, FIX(1.356927976)); /* c2 */ 1565 tmp21 = tmp20 + tmp23 + tmp25 - 1566 MULTIPLY(z2, FIX(1.821790775)); /* c2+c4+c10-c6 */ 1567 tmp20 += tmp25 + MULTIPLY(z3, FIX(2.115825087)); /* c4+c6 */ 1568 tmp23 += tmp25 - MULTIPLY(z1, FIX(1.513598477)); /* c6+c8 */ 1569 tmp24 += tmp25; 1570 tmp22 = tmp24 - MULTIPLY(z3, FIX(0.788749120)); /* c8+c10 */ 1571 tmp24 += MULTIPLY(z2, FIX(1.944413522)) - /* c2+c8 */ 1572 MULTIPLY(z1, FIX(1.390975730)); /* c4+c10 */ 1573 tmp25 = tmp10 - MULTIPLY(z4, FIX(1.414213562)); /* c0 */ 1574 1575 /* Odd part */ 1576 1577 z1 = (INT32) wsptr[1]; 1578 z2 = (INT32) wsptr[3]; 1579 z3 = (INT32) wsptr[5]; 1580 z4 = (INT32) wsptr[7]; 1581 1582 tmp11 = z1 + z2; 1583 tmp14 = MULTIPLY(tmp11 + z3 + z4, FIX(0.398430003)); /* c9 */ 1584 tmp11 = MULTIPLY(tmp11, FIX(0.887983902)); /* c3-c9 */ 1585 tmp12 = MULTIPLY(z1 + z3, FIX(0.670361295)); /* c5-c9 */ 1586 tmp13 = tmp14 + MULTIPLY(z1 + z4, FIX(0.366151574)); /* c7-c9 */ 1587 tmp10 = tmp11 + tmp12 + tmp13 - 1588 MULTIPLY(z1, FIX(0.923107866)); /* c7+c5+c3-c1-2*c9 */ 1589 z1 = tmp14 - MULTIPLY(z2 + z3, FIX(1.163011579)); /* c7+c9 */ 1590 tmp11 += z1 + MULTIPLY(z2, FIX(2.073276588)); /* c1+c7+3*c9-c3 */ 1591 tmp12 += z1 - MULTIPLY(z3, FIX(1.192193623)); /* c3+c5-c7-c9 */ 1592 z1 = MULTIPLY(z2 + z4, - FIX(1.798248910)); /* -(c1+c9) */ 1593 tmp11 += z1; 1594 tmp13 += z1 + MULTIPLY(z4, FIX(2.102458632)); /* c1+c5+c9-c7 */ 1595 tmp14 += MULTIPLY(z2, - FIX(1.467221301)) + /* -(c5+c9) */ 1596 MULTIPLY(z3, FIX(1.001388905)) - /* c1-c9 */ 1597 MULTIPLY(z4, FIX(1.684843907)); /* c3+c9 */ 1598 1599 /* Final output stage */ 1600 1601 outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp20 + tmp10, 1602 CONST_BITS+PASS1_BITS+3) 1603 & RANGE_MASK]; 1604 outptr[10] = range_limit[(int) RIGHT_SHIFT(tmp20 - tmp10, 1605 CONST_BITS+PASS1_BITS+3) 1606 & RANGE_MASK]; 1607 outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp21 + tmp11, 1608 CONST_BITS+PASS1_BITS+3) 1609 & RANGE_MASK]; 1610 outptr[9] = range_limit[(int) RIGHT_SHIFT(tmp21 - tmp11, 1611 CONST_BITS+PASS1_BITS+3) 1612 & RANGE_MASK]; 1613 outptr[2] = range_limit[(int) RIGHT_SHIFT(tmp22 + tmp12, 1614 CONST_BITS+PASS1_BITS+3) 1615 & RANGE_MASK]; 1616 outptr[8] = range_limit[(int) RIGHT_SHIFT(tmp22 - tmp12, 1617 CONST_BITS+PASS1_BITS+3) 1618 & RANGE_MASK]; 1619 outptr[3] = range_limit[(int) RIGHT_SHIFT(tmp23 + tmp13, 1620 CONST_BITS+PASS1_BITS+3) 1621 & RANGE_MASK]; 1622 outptr[7] = range_limit[(int) RIGHT_SHIFT(tmp23 - tmp13, 1623 CONST_BITS+PASS1_BITS+3) 1624 & RANGE_MASK]; 1625 outptr[4] = range_limit[(int) RIGHT_SHIFT(tmp24 + tmp14, 1626 CONST_BITS+PASS1_BITS+3) 1627 & RANGE_MASK]; 1628 outptr[6] = range_limit[(int) RIGHT_SHIFT(tmp24 - tmp14, 1629 CONST_BITS+PASS1_BITS+3) 1630 & RANGE_MASK]; 1631 outptr[5] = range_limit[(int) RIGHT_SHIFT(tmp25, 1632 CONST_BITS+PASS1_BITS+3) 1633 & RANGE_MASK]; 1634 1635 wsptr += 8; /* advance pointer to next row */ 1636 } 1637 } 1638 1639 1640 /* 1641 * Perform dequantization and inverse DCT on one block of coefficients, 1642 * producing a 12x12 output block. 1643 * 1644 * Optimized algorithm with 15 multiplications in the 1-D kernel. 1645 * cK represents sqrt(2) * cos(K*pi/24). 1646 */ 1647 1648 GLOBAL(void) 1649 jpeg_idct_12x12 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 1650 JCOEFPTR coef_block, 1651 JSAMPARRAY output_buf, JDIMENSION output_col) 1652 { 1653 INT32 tmp10, tmp11, tmp12, tmp13, tmp14, tmp15; 1654 INT32 tmp20, tmp21, tmp22, tmp23, tmp24, tmp25; 1655 INT32 z1, z2, z3, z4; 1656 JCOEFPTR inptr; 1657 ISLOW_MULT_TYPE * quantptr; 1658 int * wsptr; 1659 JSAMPROW outptr; 1660 JSAMPLE *range_limit = IDCT_range_limit(cinfo); 1661 int ctr; 1662 int workspace[8*12]; /* buffers data between passes */ 1663 SHIFT_TEMPS 1664 1665 /* Pass 1: process columns from input, store into work array. */ 1666 1667 inptr = coef_block; 1668 quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 1669 wsptr = workspace; 1670 for (ctr = 0; ctr < 8; ctr++, inptr++, quantptr++, wsptr++) { 1671 /* Even part */ 1672 1673 z3 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); 1674 z3 <<= CONST_BITS; 1675 /* Add fudge factor here for final descale. */ 1676 z3 += ONE << (CONST_BITS-PASS1_BITS-1); 1677 1678 z4 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]); 1679 z4 = MULTIPLY(z4, FIX(1.224744871)); /* c4 */ 1680 1681 tmp10 = z3 + z4; 1682 tmp11 = z3 - z4; 1683 1684 z1 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]); 1685 z4 = MULTIPLY(z1, FIX(1.366025404)); /* c2 */ 1686 z1 <<= CONST_BITS; 1687 z2 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]); 1688 z2 <<= CONST_BITS; 1689 1690 tmp12 = z1 - z2; 1691 1692 tmp21 = z3 + tmp12; 1693 tmp24 = z3 - tmp12; 1694 1695 tmp12 = z4 + z2; 1696 1697 tmp20 = tmp10 + tmp12; 1698 tmp25 = tmp10 - tmp12; 1699 1700 tmp12 = z4 - z1 - z2; 1701 1702 tmp22 = tmp11 + tmp12; 1703 tmp23 = tmp11 - tmp12; 1704 1705 /* Odd part */ 1706 1707 z1 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); 1708 z2 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]); 1709 z3 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]); 1710 z4 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]); 1711 1712 tmp11 = MULTIPLY(z2, FIX(1.306562965)); /* c3 */ 1713 tmp14 = MULTIPLY(z2, - FIX_0_541196100); /* -c9 */ 1714 1715 tmp10 = z1 + z3; 1716 tmp15 = MULTIPLY(tmp10 + z4, FIX(0.860918669)); /* c7 */ 1717 tmp12 = tmp15 + MULTIPLY(tmp10, FIX(0.261052384)); /* c5-c7 */ 1718 tmp10 = tmp12 + tmp11 + MULTIPLY(z1, FIX(0.280143716)); /* c1-c5 */ 1719 tmp13 = MULTIPLY(z3 + z4, - FIX(1.045510580)); /* -(c7+c11) */ 1720 tmp12 += tmp13 + tmp14 - MULTIPLY(z3, FIX(1.478575242)); /* c1+c5-c7-c11 */ 1721 tmp13 += tmp15 - tmp11 + MULTIPLY(z4, FIX(1.586706681)); /* c1+c11 */ 1722 tmp15 += tmp14 - MULTIPLY(z1, FIX(0.676326758)) - /* c7-c11 */ 1723 MULTIPLY(z4, FIX(1.982889723)); /* c5+c7 */ 1724 1725 z1 -= z4; 1726 z2 -= z3; 1727 z3 = MULTIPLY(z1 + z2, FIX_0_541196100); /* c9 */ 1728 tmp11 = z3 + MULTIPLY(z1, FIX_0_765366865); /* c3-c9 */ 1729 tmp14 = z3 - MULTIPLY(z2, FIX_1_847759065); /* c3+c9 */ 1730 1731 /* Final output stage */ 1732 1733 wsptr[8*0] = (int) RIGHT_SHIFT(tmp20 + tmp10, CONST_BITS-PASS1_BITS); 1734 wsptr[8*11] = (int) RIGHT_SHIFT(tmp20 - tmp10, CONST_BITS-PASS1_BITS); 1735 wsptr[8*1] = (int) RIGHT_SHIFT(tmp21 + tmp11, CONST_BITS-PASS1_BITS); 1736 wsptr[8*10] = (int) RIGHT_SHIFT(tmp21 - tmp11, CONST_BITS-PASS1_BITS); 1737 wsptr[8*2] = (int) RIGHT_SHIFT(tmp22 + tmp12, CONST_BITS-PASS1_BITS); 1738 wsptr[8*9] = (int) RIGHT_SHIFT(tmp22 - tmp12, CONST_BITS-PASS1_BITS); 1739 wsptr[8*3] = (int) RIGHT_SHIFT(tmp23 + tmp13, CONST_BITS-PASS1_BITS); 1740 wsptr[8*8] = (int) RIGHT_SHIFT(tmp23 - tmp13, CONST_BITS-PASS1_BITS); 1741 wsptr[8*4] = (int) RIGHT_SHIFT(tmp24 + tmp14, CONST_BITS-PASS1_BITS); 1742 wsptr[8*7] = (int) RIGHT_SHIFT(tmp24 - tmp14, CONST_BITS-PASS1_BITS); 1743 wsptr[8*5] = (int) RIGHT_SHIFT(tmp25 + tmp15, CONST_BITS-PASS1_BITS); 1744 wsptr[8*6] = (int) RIGHT_SHIFT(tmp25 - tmp15, CONST_BITS-PASS1_BITS); 1745 } 1746 1747 /* Pass 2: process 12 rows from work array, store into output array. */ 1748 1749 wsptr = workspace; 1750 for (ctr = 0; ctr < 12; ctr++) { 1751 outptr = output_buf[ctr] + output_col; 1752 1753 /* Even part */ 1754 1755 /* Add fudge factor here for final descale. */ 1756 z3 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2)); 1757 z3 <<= CONST_BITS; 1758 1759 z4 = (INT32) wsptr[4]; 1760 z4 = MULTIPLY(z4, FIX(1.224744871)); /* c4 */ 1761 1762 tmp10 = z3 + z4; 1763 tmp11 = z3 - z4; 1764 1765 z1 = (INT32) wsptr[2]; 1766 z4 = MULTIPLY(z1, FIX(1.366025404)); /* c2 */ 1767 z1 <<= CONST_BITS; 1768 z2 = (INT32) wsptr[6]; 1769 z2 <<= CONST_BITS; 1770 1771 tmp12 = z1 - z2; 1772 1773 tmp21 = z3 + tmp12; 1774 tmp24 = z3 - tmp12; 1775 1776 tmp12 = z4 + z2; 1777 1778 tmp20 = tmp10 + tmp12; 1779 tmp25 = tmp10 - tmp12; 1780 1781 tmp12 = z4 - z1 - z2; 1782 1783 tmp22 = tmp11 + tmp12; 1784 tmp23 = tmp11 - tmp12; 1785 1786 /* Odd part */ 1787 1788 z1 = (INT32) wsptr[1]; 1789 z2 = (INT32) wsptr[3]; 1790 z3 = (INT32) wsptr[5]; 1791 z4 = (INT32) wsptr[7]; 1792 1793 tmp11 = MULTIPLY(z2, FIX(1.306562965)); /* c3 */ 1794 tmp14 = MULTIPLY(z2, - FIX_0_541196100); /* -c9 */ 1795 1796 tmp10 = z1 + z3; 1797 tmp15 = MULTIPLY(tmp10 + z4, FIX(0.860918669)); /* c7 */ 1798 tmp12 = tmp15 + MULTIPLY(tmp10, FIX(0.261052384)); /* c5-c7 */ 1799 tmp10 = tmp12 + tmp11 + MULTIPLY(z1, FIX(0.280143716)); /* c1-c5 */ 1800 tmp13 = MULTIPLY(z3 + z4, - FIX(1.045510580)); /* -(c7+c11) */ 1801 tmp12 += tmp13 + tmp14 - MULTIPLY(z3, FIX(1.478575242)); /* c1+c5-c7-c11 */ 1802 tmp13 += tmp15 - tmp11 + MULTIPLY(z4, FIX(1.586706681)); /* c1+c11 */ 1803 tmp15 += tmp14 - MULTIPLY(z1, FIX(0.676326758)) - /* c7-c11 */ 1804 MULTIPLY(z4, FIX(1.982889723)); /* c5+c7 */ 1805 1806 z1 -= z4; 1807 z2 -= z3; 1808 z3 = MULTIPLY(z1 + z2, FIX_0_541196100); /* c9 */ 1809 tmp11 = z3 + MULTIPLY(z1, FIX_0_765366865); /* c3-c9 */ 1810 tmp14 = z3 - MULTIPLY(z2, FIX_1_847759065); /* c3+c9 */ 1811 1812 /* Final output stage */ 1813 1814 outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp20 + tmp10, 1815 CONST_BITS+PASS1_BITS+3) 1816 & RANGE_MASK]; 1817 outptr[11] = range_limit[(int) RIGHT_SHIFT(tmp20 - tmp10, 1818 CONST_BITS+PASS1_BITS+3) 1819 & RANGE_MASK]; 1820 outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp21 + tmp11, 1821 CONST_BITS+PASS1_BITS+3) 1822 & RANGE_MASK]; 1823 outptr[10] = range_limit[(int) RIGHT_SHIFT(tmp21 - tmp11, 1824 CONST_BITS+PASS1_BITS+3) 1825 & RANGE_MASK]; 1826 outptr[2] = range_limit[(int) RIGHT_SHIFT(tmp22 + tmp12, 1827 CONST_BITS+PASS1_BITS+3) 1828 & RANGE_MASK]; 1829 outptr[9] = range_limit[(int) RIGHT_SHIFT(tmp22 - tmp12, 1830 CONST_BITS+PASS1_BITS+3) 1831 & RANGE_MASK]; 1832 outptr[3] = range_limit[(int) RIGHT_SHIFT(tmp23 + tmp13, 1833 CONST_BITS+PASS1_BITS+3) 1834 & RANGE_MASK]; 1835 outptr[8] = range_limit[(int) RIGHT_SHIFT(tmp23 - tmp13, 1836 CONST_BITS+PASS1_BITS+3) 1837 & RANGE_MASK]; 1838 outptr[4] = range_limit[(int) RIGHT_SHIFT(tmp24 + tmp14, 1839 CONST_BITS+PASS1_BITS+3) 1840 & RANGE_MASK]; 1841 outptr[7] = range_limit[(int) RIGHT_SHIFT(tmp24 - tmp14, 1842 CONST_BITS+PASS1_BITS+3) 1843 & RANGE_MASK]; 1844 outptr[5] = range_limit[(int) RIGHT_SHIFT(tmp25 + tmp15, 1845 CONST_BITS+PASS1_BITS+3) 1846 & RANGE_MASK]; 1847 outptr[6] = range_limit[(int) RIGHT_SHIFT(tmp25 - tmp15, 1848 CONST_BITS+PASS1_BITS+3) 1849 & RANGE_MASK]; 1850 1851 wsptr += 8; /* advance pointer to next row */ 1852 } 1853 } 1854 1855 1856 /* 1857 * Perform dequantization and inverse DCT on one block of coefficients, 1858 * producing a 13x13 output block. 1859 * 1860 * Optimized algorithm with 29 multiplications in the 1-D kernel. 1861 * cK represents sqrt(2) * cos(K*pi/26). 1862 */ 1863 1864 GLOBAL(void) 1865 jpeg_idct_13x13 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 1866 JCOEFPTR coef_block, 1867 JSAMPARRAY output_buf, JDIMENSION output_col) 1868 { 1869 INT32 tmp10, tmp11, tmp12, tmp13, tmp14, tmp15; 1870 INT32 tmp20, tmp21, tmp22, tmp23, tmp24, tmp25, tmp26; 1871 INT32 z1, z2, z3, z4; 1872 JCOEFPTR inptr; 1873 ISLOW_MULT_TYPE * quantptr; 1874 int * wsptr; 1875 JSAMPROW outptr; 1876 JSAMPLE *range_limit = IDCT_range_limit(cinfo); 1877 int ctr; 1878 int workspace[8*13]; /* buffers data between passes */ 1879 SHIFT_TEMPS 1880 1881 /* Pass 1: process columns from input, store into work array. */ 1882 1883 inptr = coef_block; 1884 quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 1885 wsptr = workspace; 1886 for (ctr = 0; ctr < 8; ctr++, inptr++, quantptr++, wsptr++) { 1887 /* Even part */ 1888 1889 z1 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); 1890 z1 <<= CONST_BITS; 1891 /* Add fudge factor here for final descale. */ 1892 z1 += ONE << (CONST_BITS-PASS1_BITS-1); 1893 1894 z2 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]); 1895 z3 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]); 1896 z4 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]); 1897 1898 tmp10 = z3 + z4; 1899 tmp11 = z3 - z4; 1900 1901 tmp12 = MULTIPLY(tmp10, FIX(1.155388986)); /* (c4+c6)/2 */ 1902 tmp13 = MULTIPLY(tmp11, FIX(0.096834934)) + z1; /* (c4-c6)/2 */ 1903 1904 tmp20 = MULTIPLY(z2, FIX(1.373119086)) + tmp12 + tmp13; /* c2 */ 1905 tmp22 = MULTIPLY(z2, FIX(0.501487041)) - tmp12 + tmp13; /* c10 */ 1906 1907 tmp12 = MULTIPLY(tmp10, FIX(0.316450131)); /* (c8-c12)/2 */ 1908 tmp13 = MULTIPLY(tmp11, FIX(0.486914739)) + z1; /* (c8+c12)/2 */ 1909 1910 tmp21 = MULTIPLY(z2, FIX(1.058554052)) - tmp12 + tmp13; /* c6 */ 1911 tmp25 = MULTIPLY(z2, - FIX(1.252223920)) + tmp12 + tmp13; /* c4 */ 1912 1913 tmp12 = MULTIPLY(tmp10, FIX(0.435816023)); /* (c2-c10)/2 */ 1914 tmp13 = MULTIPLY(tmp11, FIX(0.937303064)) - z1; /* (c2+c10)/2 */ 1915 1916 tmp23 = MULTIPLY(z2, - FIX(0.170464608)) - tmp12 - tmp13; /* c12 */ 1917 tmp24 = MULTIPLY(z2, - FIX(0.803364869)) + tmp12 - tmp13; /* c8 */ 1918 1919 tmp26 = MULTIPLY(tmp11 - z2, FIX(1.414213562)) + z1; /* c0 */ 1920 1921 /* Odd part */ 1922 1923 z1 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); 1924 z2 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]); 1925 z3 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]); 1926 z4 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]); 1927 1928 tmp11 = MULTIPLY(z1 + z2, FIX(1.322312651)); /* c3 */ 1929 tmp12 = MULTIPLY(z1 + z3, FIX(1.163874945)); /* c5 */ 1930 tmp15 = z1 + z4; 1931 tmp13 = MULTIPLY(tmp15, FIX(0.937797057)); /* c7 */ 1932 tmp10 = tmp11 + tmp12 + tmp13 - 1933 MULTIPLY(z1, FIX(2.020082300)); /* c7+c5+c3-c1 */ 1934 tmp14 = MULTIPLY(z2 + z3, - FIX(0.338443458)); /* -c11 */ 1935 tmp11 += tmp14 + MULTIPLY(z2, FIX(0.837223564)); /* c5+c9+c11-c3 */ 1936 tmp12 += tmp14 - MULTIPLY(z3, FIX(1.572116027)); /* c1+c5-c9-c11 */ 1937 tmp14 = MULTIPLY(z2 + z4, - FIX(1.163874945)); /* -c5 */ 1938 tmp11 += tmp14; 1939 tmp13 += tmp14 + MULTIPLY(z4, FIX(2.205608352)); /* c3+c5+c9-c7 */ 1940 tmp14 = MULTIPLY(z3 + z4, - FIX(0.657217813)); /* -c9 */ 1941 tmp12 += tmp14; 1942 tmp13 += tmp14; 1943 tmp15 = MULTIPLY(tmp15, FIX(0.338443458)); /* c11 */ 1944 tmp14 = tmp15 + MULTIPLY(z1, FIX(0.318774355)) - /* c9-c11 */ 1945 MULTIPLY(z2, FIX(0.466105296)); /* c1-c7 */ 1946 z1 = MULTIPLY(z3 - z2, FIX(0.937797057)); /* c7 */ 1947 tmp14 += z1; 1948 tmp15 += z1 + MULTIPLY(z3, FIX(0.384515595)) - /* c3-c7 */ 1949 MULTIPLY(z4, FIX(1.742345811)); /* c1+c11 */ 1950 1951 /* Final output stage */ 1952 1953 wsptr[8*0] = (int) RIGHT_SHIFT(tmp20 + tmp10, CONST_BITS-PASS1_BITS); 1954 wsptr[8*12] = (int) RIGHT_SHIFT(tmp20 - tmp10, CONST_BITS-PASS1_BITS); 1955 wsptr[8*1] = (int) RIGHT_SHIFT(tmp21 + tmp11, CONST_BITS-PASS1_BITS); 1956 wsptr[8*11] = (int) RIGHT_SHIFT(tmp21 - tmp11, CONST_BITS-PASS1_BITS); 1957 wsptr[8*2] = (int) RIGHT_SHIFT(tmp22 + tmp12, CONST_BITS-PASS1_BITS); 1958 wsptr[8*10] = (int) RIGHT_SHIFT(tmp22 - tmp12, CONST_BITS-PASS1_BITS); 1959 wsptr[8*3] = (int) RIGHT_SHIFT(tmp23 + tmp13, CONST_BITS-PASS1_BITS); 1960 wsptr[8*9] = (int) RIGHT_SHIFT(tmp23 - tmp13, CONST_BITS-PASS1_BITS); 1961 wsptr[8*4] = (int) RIGHT_SHIFT(tmp24 + tmp14, CONST_BITS-PASS1_BITS); 1962 wsptr[8*8] = (int) RIGHT_SHIFT(tmp24 - tmp14, CONST_BITS-PASS1_BITS); 1963 wsptr[8*5] = (int) RIGHT_SHIFT(tmp25 + tmp15, CONST_BITS-PASS1_BITS); 1964 wsptr[8*7] = (int) RIGHT_SHIFT(tmp25 - tmp15, CONST_BITS-PASS1_BITS); 1965 wsptr[8*6] = (int) RIGHT_SHIFT(tmp26, CONST_BITS-PASS1_BITS); 1966 } 1967 1968 /* Pass 2: process 13 rows from work array, store into output array. */ 1969 1970 wsptr = workspace; 1971 for (ctr = 0; ctr < 13; ctr++) { 1972 outptr = output_buf[ctr] + output_col; 1973 1974 /* Even part */ 1975 1976 /* Add fudge factor here for final descale. */ 1977 z1 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2)); 1978 z1 <<= CONST_BITS; 1979 1980 z2 = (INT32) wsptr[2]; 1981 z3 = (INT32) wsptr[4]; 1982 z4 = (INT32) wsptr[6]; 1983 1984 tmp10 = z3 + z4; 1985 tmp11 = z3 - z4; 1986 1987 tmp12 = MULTIPLY(tmp10, FIX(1.155388986)); /* (c4+c6)/2 */ 1988 tmp13 = MULTIPLY(tmp11, FIX(0.096834934)) + z1; /* (c4-c6)/2 */ 1989 1990 tmp20 = MULTIPLY(z2, FIX(1.373119086)) + tmp12 + tmp13; /* c2 */ 1991 tmp22 = MULTIPLY(z2, FIX(0.501487041)) - tmp12 + tmp13; /* c10 */ 1992 1993 tmp12 = MULTIPLY(tmp10, FIX(0.316450131)); /* (c8-c12)/2 */ 1994 tmp13 = MULTIPLY(tmp11, FIX(0.486914739)) + z1; /* (c8+c12)/2 */ 1995 1996 tmp21 = MULTIPLY(z2, FIX(1.058554052)) - tmp12 + tmp13; /* c6 */ 1997 tmp25 = MULTIPLY(z2, - FIX(1.252223920)) + tmp12 + tmp13; /* c4 */ 1998 1999 tmp12 = MULTIPLY(tmp10, FIX(0.435816023)); /* (c2-c10)/2 */ 2000 tmp13 = MULTIPLY(tmp11, FIX(0.937303064)) - z1; /* (c2+c10)/2 */ 2001 2002 tmp23 = MULTIPLY(z2, - FIX(0.170464608)) - tmp12 - tmp13; /* c12 */ 2003 tmp24 = MULTIPLY(z2, - FIX(0.803364869)) + tmp12 - tmp13; /* c8 */ 2004 2005 tmp26 = MULTIPLY(tmp11 - z2, FIX(1.414213562)) + z1; /* c0 */ 2006 2007 /* Odd part */ 2008 2009 z1 = (INT32) wsptr[1]; 2010 z2 = (INT32) wsptr[3]; 2011 z3 = (INT32) wsptr[5]; 2012 z4 = (INT32) wsptr[7]; 2013 2014 tmp11 = MULTIPLY(z1 + z2, FIX(1.322312651)); /* c3 */ 2015 tmp12 = MULTIPLY(z1 + z3, FIX(1.163874945)); /* c5 */ 2016 tmp15 = z1 + z4; 2017 tmp13 = MULTIPLY(tmp15, FIX(0.937797057)); /* c7 */ 2018 tmp10 = tmp11 + tmp12 + tmp13 - 2019 MULTIPLY(z1, FIX(2.020082300)); /* c7+c5+c3-c1 */ 2020 tmp14 = MULTIPLY(z2 + z3, - FIX(0.338443458)); /* -c11 */ 2021 tmp11 += tmp14 + MULTIPLY(z2, FIX(0.837223564)); /* c5+c9+c11-c3 */ 2022 tmp12 += tmp14 - MULTIPLY(z3, FIX(1.572116027)); /* c1+c5-c9-c11 */ 2023 tmp14 = MULTIPLY(z2 + z4, - FIX(1.163874945)); /* -c5 */ 2024 tmp11 += tmp14; 2025 tmp13 += tmp14 + MULTIPLY(z4, FIX(2.205608352)); /* c3+c5+c9-c7 */ 2026 tmp14 = MULTIPLY(z3 + z4, - FIX(0.657217813)); /* -c9 */ 2027 tmp12 += tmp14; 2028 tmp13 += tmp14; 2029 tmp15 = MULTIPLY(tmp15, FIX(0.338443458)); /* c11 */ 2030 tmp14 = tmp15 + MULTIPLY(z1, FIX(0.318774355)) - /* c9-c11 */ 2031 MULTIPLY(z2, FIX(0.466105296)); /* c1-c7 */ 2032 z1 = MULTIPLY(z3 - z2, FIX(0.937797057)); /* c7 */ 2033 tmp14 += z1; 2034 tmp15 += z1 + MULTIPLY(z3, FIX(0.384515595)) - /* c3-c7 */ 2035 MULTIPLY(z4, FIX(1.742345811)); /* c1+c11 */ 2036 2037 /* Final output stage */ 2038 2039 outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp20 + tmp10, 2040 CONST_BITS+PASS1_BITS+3) 2041 & RANGE_MASK]; 2042 outptr[12] = range_limit[(int) RIGHT_SHIFT(tmp20 - tmp10, 2043 CONST_BITS+PASS1_BITS+3) 2044 & RANGE_MASK]; 2045 outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp21 + tmp11, 2046 CONST_BITS+PASS1_BITS+3) 2047 & RANGE_MASK]; 2048 outptr[11] = range_limit[(int) RIGHT_SHIFT(tmp21 - tmp11, 2049 CONST_BITS+PASS1_BITS+3) 2050 & RANGE_MASK]; 2051 outptr[2] = range_limit[(int) RIGHT_SHIFT(tmp22 + tmp12, 2052 CONST_BITS+PASS1_BITS+3) 2053 & RANGE_MASK]; 2054 outptr[10] = range_limit[(int) RIGHT_SHIFT(tmp22 - tmp12, 2055 CONST_BITS+PASS1_BITS+3) 2056 & RANGE_MASK]; 2057 outptr[3] = range_limit[(int) RIGHT_SHIFT(tmp23 + tmp13, 2058 CONST_BITS+PASS1_BITS+3) 2059 & RANGE_MASK]; 2060 outptr[9] = range_limit[(int) RIGHT_SHIFT(tmp23 - tmp13, 2061 CONST_BITS+PASS1_BITS+3) 2062 & RANGE_MASK]; 2063 outptr[4] = range_limit[(int) RIGHT_SHIFT(tmp24 + tmp14, 2064 CONST_BITS+PASS1_BITS+3) 2065 & RANGE_MASK]; 2066 outptr[8] = range_limit[(int) RIGHT_SHIFT(tmp24 - tmp14, 2067 CONST_BITS+PASS1_BITS+3) 2068 & RANGE_MASK]; 2069 outptr[5] = range_limit[(int) RIGHT_SHIFT(tmp25 + tmp15, 2070 CONST_BITS+PASS1_BITS+3) 2071 & RANGE_MASK]; 2072 outptr[7] = range_limit[(int) RIGHT_SHIFT(tmp25 - tmp15, 2073 CONST_BITS+PASS1_BITS+3) 2074 & RANGE_MASK]; 2075 outptr[6] = range_limit[(int) RIGHT_SHIFT(tmp26, 2076 CONST_BITS+PASS1_BITS+3) 2077 & RANGE_MASK]; 2078 2079 wsptr += 8; /* advance pointer to next row */ 2080 } 2081 } 2082 2083 2084 /* 2085 * Perform dequantization and inverse DCT on one block of coefficients, 2086 * producing a 14x14 output block. 2087 * 2088 * Optimized algorithm with 20 multiplications in the 1-D kernel. 2089 * cK represents sqrt(2) * cos(K*pi/28). 2090 */ 2091 2092 GLOBAL(void) 2093 jpeg_idct_14x14 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 2094 JCOEFPTR coef_block, 2095 JSAMPARRAY output_buf, JDIMENSION output_col) 2096 { 2097 INT32 tmp10, tmp11, tmp12, tmp13, tmp14, tmp15, tmp16; 2098 INT32 tmp20, tmp21, tmp22, tmp23, tmp24, tmp25, tmp26; 2099 INT32 z1, z2, z3, z4; 2100 JCOEFPTR inptr; 2101 ISLOW_MULT_TYPE * quantptr; 2102 int * wsptr; 2103 JSAMPROW outptr; 2104 JSAMPLE *range_limit = IDCT_range_limit(cinfo); 2105 int ctr; 2106 int workspace[8*14]; /* buffers data between passes */ 2107 SHIFT_TEMPS 2108 2109 /* Pass 1: process columns from input, store into work array. */ 2110 2111 inptr = coef_block; 2112 quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 2113 wsptr = workspace; 2114 for (ctr = 0; ctr < 8; ctr++, inptr++, quantptr++, wsptr++) { 2115 /* Even part */ 2116 2117 z1 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); 2118 z1 <<= CONST_BITS; 2119 /* Add fudge factor here for final descale. */ 2120 z1 += ONE << (CONST_BITS-PASS1_BITS-1); 2121 z4 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]); 2122 z2 = MULTIPLY(z4, FIX(1.274162392)); /* c4 */ 2123 z3 = MULTIPLY(z4, FIX(0.314692123)); /* c12 */ 2124 z4 = MULTIPLY(z4, FIX(0.881747734)); /* c8 */ 2125 2126 tmp10 = z1 + z2; 2127 tmp11 = z1 + z3; 2128 tmp12 = z1 - z4; 2129 2130 tmp23 = RIGHT_SHIFT(z1 - ((z2 + z3 - z4) << 1), /* c0 = (c4+c12-c8)*2 */ 2131 CONST_BITS-PASS1_BITS); 2132 2133 z1 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]); 2134 z2 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]); 2135 2136 z3 = MULTIPLY(z1 + z2, FIX(1.105676686)); /* c6 */ 2137 2138 tmp13 = z3 + MULTIPLY(z1, FIX(0.273079590)); /* c2-c6 */ 2139 tmp14 = z3 - MULTIPLY(z2, FIX(1.719280954)); /* c6+c10 */ 2140 tmp15 = MULTIPLY(z1, FIX(0.613604268)) - /* c10 */ 2141 MULTIPLY(z2, FIX(1.378756276)); /* c2 */ 2142 2143 tmp20 = tmp10 + tmp13; 2144 tmp26 = tmp10 - tmp13; 2145 tmp21 = tmp11 + tmp14; 2146 tmp25 = tmp11 - tmp14; 2147 tmp22 = tmp12 + tmp15; 2148 tmp24 = tmp12 - tmp15; 2149 2150 /* Odd part */ 2151 2152 z1 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); 2153 z2 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]); 2154 z3 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]); 2155 z4 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]); 2156 tmp13 = z4 << CONST_BITS; 2157 2158 tmp14 = z1 + z3; 2159 tmp11 = MULTIPLY(z1 + z2, FIX(1.334852607)); /* c3 */ 2160 tmp12 = MULTIPLY(tmp14, FIX(1.197448846)); /* c5 */ 2161 tmp10 = tmp11 + tmp12 + tmp13 - MULTIPLY(z1, FIX(1.126980169)); /* c3+c5-c1 */ 2162 tmp14 = MULTIPLY(tmp14, FIX(0.752406978)); /* c9 */ 2163 tmp16 = tmp14 - MULTIPLY(z1, FIX(1.061150426)); /* c9+c11-c13 */ 2164 z1 -= z2; 2165 tmp15 = MULTIPLY(z1, FIX(0.467085129)) - tmp13; /* c11 */ 2166 tmp16 += tmp15; 2167 z1 += z4; 2168 z4 = MULTIPLY(z2 + z3, - FIX(0.158341681)) - tmp13; /* -c13 */ 2169 tmp11 += z4 - MULTIPLY(z2, FIX(0.424103948)); /* c3-c9-c13 */ 2170 tmp12 += z4 - MULTIPLY(z3, FIX(2.373959773)); /* c3+c5-c13 */ 2171 z4 = MULTIPLY(z3 - z2, FIX(1.405321284)); /* c1 */ 2172 tmp14 += z4 + tmp13 - MULTIPLY(z3, FIX(1.6906431334)); /* c1+c9-c11 */ 2173 tmp15 += z4 + MULTIPLY(z2, FIX(0.674957567)); /* c1+c11-c5 */ 2174 2175 tmp13 = (z1 - z3) << PASS1_BITS; 2176 2177 /* Final output stage */ 2178 2179 wsptr[8*0] = (int) RIGHT_SHIFT(tmp20 + tmp10, CONST_BITS-PASS1_BITS); 2180 wsptr[8*13] = (int) RIGHT_SHIFT(tmp20 - tmp10, CONST_BITS-PASS1_BITS); 2181 wsptr[8*1] = (int) RIGHT_SHIFT(tmp21 + tmp11, CONST_BITS-PASS1_BITS); 2182 wsptr[8*12] = (int) RIGHT_SHIFT(tmp21 - tmp11, CONST_BITS-PASS1_BITS); 2183 wsptr[8*2] = (int) RIGHT_SHIFT(tmp22 + tmp12, CONST_BITS-PASS1_BITS); 2184 wsptr[8*11] = (int) RIGHT_SHIFT(tmp22 - tmp12, CONST_BITS-PASS1_BITS); 2185 wsptr[8*3] = (int) (tmp23 + tmp13); 2186 wsptr[8*10] = (int) (tmp23 - tmp13); 2187 wsptr[8*4] = (int) RIGHT_SHIFT(tmp24 + tmp14, CONST_BITS-PASS1_BITS); 2188 wsptr[8*9] = (int) RIGHT_SHIFT(tmp24 - tmp14, CONST_BITS-PASS1_BITS); 2189 wsptr[8*5] = (int) RIGHT_SHIFT(tmp25 + tmp15, CONST_BITS-PASS1_BITS); 2190 wsptr[8*8] = (int) RIGHT_SHIFT(tmp25 - tmp15, CONST_BITS-PASS1_BITS); 2191 wsptr[8*6] = (int) RIGHT_SHIFT(tmp26 + tmp16, CONST_BITS-PASS1_BITS); 2192 wsptr[8*7] = (int) RIGHT_SHIFT(tmp26 - tmp16, CONST_BITS-PASS1_BITS); 2193 } 2194 2195 /* Pass 2: process 14 rows from work array, store into output array. */ 2196 2197 wsptr = workspace; 2198 for (ctr = 0; ctr < 14; ctr++) { 2199 outptr = output_buf[ctr] + output_col; 2200 2201 /* Even part */ 2202 2203 /* Add fudge factor here for final descale. */ 2204 z1 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2)); 2205 z1 <<= CONST_BITS; 2206 z4 = (INT32) wsptr[4]; 2207 z2 = MULTIPLY(z4, FIX(1.274162392)); /* c4 */ 2208 z3 = MULTIPLY(z4, FIX(0.314692123)); /* c12 */ 2209 z4 = MULTIPLY(z4, FIX(0.881747734)); /* c8 */ 2210 2211 tmp10 = z1 + z2; 2212 tmp11 = z1 + z3; 2213 tmp12 = z1 - z4; 2214 2215 tmp23 = z1 - ((z2 + z3 - z4) << 1); /* c0 = (c4+c12-c8)*2 */ 2216 2217 z1 = (INT32) wsptr[2]; 2218 z2 = (INT32) wsptr[6]; 2219 2220 z3 = MULTIPLY(z1 + z2, FIX(1.105676686)); /* c6 */ 2221 2222 tmp13 = z3 + MULTIPLY(z1, FIX(0.273079590)); /* c2-c6 */ 2223 tmp14 = z3 - MULTIPLY(z2, FIX(1.719280954)); /* c6+c10 */ 2224 tmp15 = MULTIPLY(z1, FIX(0.613604268)) - /* c10 */ 2225 MULTIPLY(z2, FIX(1.378756276)); /* c2 */ 2226 2227 tmp20 = tmp10 + tmp13; 2228 tmp26 = tmp10 - tmp13; 2229 tmp21 = tmp11 + tmp14; 2230 tmp25 = tmp11 - tmp14; 2231 tmp22 = tmp12 + tmp15; 2232 tmp24 = tmp12 - tmp15; 2233 2234 /* Odd part */ 2235 2236 z1 = (INT32) wsptr[1]; 2237 z2 = (INT32) wsptr[3]; 2238 z3 = (INT32) wsptr[5]; 2239 z4 = (INT32) wsptr[7]; 2240 z4 <<= CONST_BITS; 2241 2242 tmp14 = z1 + z3; 2243 tmp11 = MULTIPLY(z1 + z2, FIX(1.334852607)); /* c3 */ 2244 tmp12 = MULTIPLY(tmp14, FIX(1.197448846)); /* c5 */ 2245 tmp10 = tmp11 + tmp12 + z4 - MULTIPLY(z1, FIX(1.126980169)); /* c3+c5-c1 */ 2246 tmp14 = MULTIPLY(tmp14, FIX(0.752406978)); /* c9 */ 2247 tmp16 = tmp14 - MULTIPLY(z1, FIX(1.061150426)); /* c9+c11-c13 */ 2248 z1 -= z2; 2249 tmp15 = MULTIPLY(z1, FIX(0.467085129)) - z4; /* c11 */ 2250 tmp16 += tmp15; 2251 tmp13 = MULTIPLY(z2 + z3, - FIX(0.158341681)) - z4; /* -c13 */ 2252 tmp11 += tmp13 - MULTIPLY(z2, FIX(0.424103948)); /* c3-c9-c13 */ 2253 tmp12 += tmp13 - MULTIPLY(z3, FIX(2.373959773)); /* c3+c5-c13 */ 2254 tmp13 = MULTIPLY(z3 - z2, FIX(1.405321284)); /* c1 */ 2255 tmp14 += tmp13 + z4 - MULTIPLY(z3, FIX(1.6906431334)); /* c1+c9-c11 */ 2256 tmp15 += tmp13 + MULTIPLY(z2, FIX(0.674957567)); /* c1+c11-c5 */ 2257 2258 tmp13 = ((z1 - z3) << CONST_BITS) + z4; 2259 2260 /* Final output stage */ 2261 2262 outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp20 + tmp10, 2263 CONST_BITS+PASS1_BITS+3) 2264 & RANGE_MASK]; 2265 outptr[13] = range_limit[(int) RIGHT_SHIFT(tmp20 - tmp10, 2266 CONST_BITS+PASS1_BITS+3) 2267 & RANGE_MASK]; 2268 outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp21 + tmp11, 2269 CONST_BITS+PASS1_BITS+3) 2270 & RANGE_MASK]; 2271 outptr[12] = range_limit[(int) RIGHT_SHIFT(tmp21 - tmp11, 2272 CONST_BITS+PASS1_BITS+3) 2273 & RANGE_MASK]; 2274 outptr[2] = range_limit[(int) RIGHT_SHIFT(tmp22 + tmp12, 2275 CONST_BITS+PASS1_BITS+3) 2276 & RANGE_MASK]; 2277 outptr[11] = range_limit[(int) RIGHT_SHIFT(tmp22 - tmp12, 2278 CONST_BITS+PASS1_BITS+3) 2279 & RANGE_MASK]; 2280 outptr[3] = range_limit[(int) RIGHT_SHIFT(tmp23 + tmp13, 2281 CONST_BITS+PASS1_BITS+3) 2282 & RANGE_MASK]; 2283 outptr[10] = range_limit[(int) RIGHT_SHIFT(tmp23 - tmp13, 2284 CONST_BITS+PASS1_BITS+3) 2285 & RANGE_MASK]; 2286 outptr[4] = range_limit[(int) RIGHT_SHIFT(tmp24 + tmp14, 2287 CONST_BITS+PASS1_BITS+3) 2288 & RANGE_MASK]; 2289 outptr[9] = range_limit[(int) RIGHT_SHIFT(tmp24 - tmp14, 2290 CONST_BITS+PASS1_BITS+3) 2291 & RANGE_MASK]; 2292 outptr[5] = range_limit[(int) RIGHT_SHIFT(tmp25 + tmp15, 2293 CONST_BITS+PASS1_BITS+3) 2294 & RANGE_MASK]; 2295 outptr[8] = range_limit[(int) RIGHT_SHIFT(tmp25 - tmp15, 2296 CONST_BITS+PASS1_BITS+3) 2297 & RANGE_MASK]; 2298 outptr[6] = range_limit[(int) RIGHT_SHIFT(tmp26 + tmp16, 2299 CONST_BITS+PASS1_BITS+3) 2300 & RANGE_MASK]; 2301 outptr[7] = range_limit[(int) RIGHT_SHIFT(tmp26 - tmp16, 2302 CONST_BITS+PASS1_BITS+3) 2303 & RANGE_MASK]; 2304 2305 wsptr += 8; /* advance pointer to next row */ 2306 } 2307 } 2308 2309 2310 /* 2311 * Perform dequantization and inverse DCT on one block of coefficients, 2312 * producing a 15x15 output block. 2313 * 2314 * Optimized algorithm with 22 multiplications in the 1-D kernel. 2315 * cK represents sqrt(2) * cos(K*pi/30). 2316 */ 2317 2318 GLOBAL(void) 2319 jpeg_idct_15x15 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 2320 JCOEFPTR coef_block, 2321 JSAMPARRAY output_buf, JDIMENSION output_col) 2322 { 2323 INT32 tmp10, tmp11, tmp12, tmp13, tmp14, tmp15, tmp16; 2324 INT32 tmp20, tmp21, tmp22, tmp23, tmp24, tmp25, tmp26, tmp27; 2325 INT32 z1, z2, z3, z4; 2326 JCOEFPTR inptr; 2327 ISLOW_MULT_TYPE * quantptr; 2328 int * wsptr; 2329 JSAMPROW outptr; 2330 JSAMPLE *range_limit = IDCT_range_limit(cinfo); 2331 int ctr; 2332 int workspace[8*15]; /* buffers data between passes */ 2333 SHIFT_TEMPS 2334 2335 /* Pass 1: process columns from input, store into work array. */ 2336 2337 inptr = coef_block; 2338 quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 2339 wsptr = workspace; 2340 for (ctr = 0; ctr < 8; ctr++, inptr++, quantptr++, wsptr++) { 2341 /* Even part */ 2342 2343 z1 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); 2344 z1 <<= CONST_BITS; 2345 /* Add fudge factor here for final descale. */ 2346 z1 += ONE << (CONST_BITS-PASS1_BITS-1); 2347 2348 z2 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]); 2349 z3 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]); 2350 z4 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]); 2351 2352 tmp10 = MULTIPLY(z4, FIX(0.437016024)); /* c12 */ 2353 tmp11 = MULTIPLY(z4, FIX(1.144122806)); /* c6 */ 2354 2355 tmp12 = z1 - tmp10; 2356 tmp13 = z1 + tmp11; 2357 z1 -= (tmp11 - tmp10) << 1; /* c0 = (c6-c12)*2 */ 2358 2359 z4 = z2 - z3; 2360 z3 += z2; 2361 tmp10 = MULTIPLY(z3, FIX(1.337628990)); /* (c2+c4)/2 */ 2362 tmp11 = MULTIPLY(z4, FIX(0.045680613)); /* (c2-c4)/2 */ 2363 z2 = MULTIPLY(z2, FIX(1.439773946)); /* c4+c14 */ 2364 2365 tmp20 = tmp13 + tmp10 + tmp11; 2366 tmp23 = tmp12 - tmp10 + tmp11 + z2; 2367 2368 tmp10 = MULTIPLY(z3, FIX(0.547059574)); /* (c8+c14)/2 */ 2369 tmp11 = MULTIPLY(z4, FIX(0.399234004)); /* (c8-c14)/2 */ 2370 2371 tmp25 = tmp13 - tmp10 - tmp11; 2372 tmp26 = tmp12 + tmp10 - tmp11 - z2; 2373 2374 tmp10 = MULTIPLY(z3, FIX(0.790569415)); /* (c6+c12)/2 */ 2375 tmp11 = MULTIPLY(z4, FIX(0.353553391)); /* (c6-c12)/2 */ 2376 2377 tmp21 = tmp12 + tmp10 + tmp11; 2378 tmp24 = tmp13 - tmp10 + tmp11; 2379 tmp11 += tmp11; 2380 tmp22 = z1 + tmp11; /* c10 = c6-c12 */ 2381 tmp27 = z1 - tmp11 - tmp11; /* c0 = (c6-c12)*2 */ 2382 2383 /* Odd part */ 2384 2385 z1 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); 2386 z2 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]); 2387 z4 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]); 2388 z3 = MULTIPLY(z4, FIX(1.224744871)); /* c5 */ 2389 z4 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]); 2390 2391 tmp13 = z2 - z4; 2392 tmp15 = MULTIPLY(z1 + tmp13, FIX(0.831253876)); /* c9 */ 2393 tmp11 = tmp15 + MULTIPLY(z1, FIX(0.513743148)); /* c3-c9 */ 2394 tmp14 = tmp15 - MULTIPLY(tmp13, FIX(2.176250899)); /* c3+c9 */ 2395 2396 tmp13 = MULTIPLY(z2, - FIX(0.831253876)); /* -c9 */ 2397 tmp15 = MULTIPLY(z2, - FIX(1.344997024)); /* -c3 */ 2398 z2 = z1 - z4; 2399 tmp12 = z3 + MULTIPLY(z2, FIX(1.406466353)); /* c1 */ 2400 2401 tmp10 = tmp12 + MULTIPLY(z4, FIX(2.457431844)) - tmp15; /* c1+c7 */ 2402 tmp16 = tmp12 - MULTIPLY(z1, FIX(1.112434820)) + tmp13; /* c1-c13 */ 2403 tmp12 = MULTIPLY(z2, FIX(1.224744871)) - z3; /* c5 */ 2404 z2 = MULTIPLY(z1 + z4, FIX(0.575212477)); /* c11 */ 2405 tmp13 += z2 + MULTIPLY(z1, FIX(0.475753014)) - z3; /* c7-c11 */ 2406 tmp15 += z2 - MULTIPLY(z4, FIX(0.869244010)) + z3; /* c11+c13 */ 2407 2408 /* Final output stage */ 2409 2410 wsptr[8*0] = (int) RIGHT_SHIFT(tmp20 + tmp10, CONST_BITS-PASS1_BITS); 2411 wsptr[8*14] = (int) RIGHT_SHIFT(tmp20 - tmp10, CONST_BITS-PASS1_BITS); 2412 wsptr[8*1] = (int) RIGHT_SHIFT(tmp21 + tmp11, CONST_BITS-PASS1_BITS); 2413 wsptr[8*13] = (int) RIGHT_SHIFT(tmp21 - tmp11, CONST_BITS-PASS1_BITS); 2414 wsptr[8*2] = (int) RIGHT_SHIFT(tmp22 + tmp12, CONST_BITS-PASS1_BITS); 2415 wsptr[8*12] = (int) RIGHT_SHIFT(tmp22 - tmp12, CONST_BITS-PASS1_BITS); 2416 wsptr[8*3] = (int) RIGHT_SHIFT(tmp23 + tmp13, CONST_BITS-PASS1_BITS); 2417 wsptr[8*11] = (int) RIGHT_SHIFT(tmp23 - tmp13, CONST_BITS-PASS1_BITS); 2418 wsptr[8*4] = (int) RIGHT_SHIFT(tmp24 + tmp14, CONST_BITS-PASS1_BITS); 2419 wsptr[8*10] = (int) RIGHT_SHIFT(tmp24 - tmp14, CONST_BITS-PASS1_BITS); 2420 wsptr[8*5] = (int) RIGHT_SHIFT(tmp25 + tmp15, CONST_BITS-PASS1_BITS); 2421 wsptr[8*9] = (int) RIGHT_SHIFT(tmp25 - tmp15, CONST_BITS-PASS1_BITS); 2422 wsptr[8*6] = (int) RIGHT_SHIFT(tmp26 + tmp16, CONST_BITS-PASS1_BITS); 2423 wsptr[8*8] = (int) RIGHT_SHIFT(tmp26 - tmp16, CONST_BITS-PASS1_BITS); 2424 wsptr[8*7] = (int) RIGHT_SHIFT(tmp27, CONST_BITS-PASS1_BITS); 2425 } 2426 2427 /* Pass 2: process 15 rows from work array, store into output array. */ 2428 2429 wsptr = workspace; 2430 for (ctr = 0; ctr < 15; ctr++) { 2431 outptr = output_buf[ctr] + output_col; 2432 2433 /* Even part */ 2434 2435 /* Add fudge factor here for final descale. */ 2436 z1 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2)); 2437 z1 <<= CONST_BITS; 2438 2439 z2 = (INT32) wsptr[2]; 2440 z3 = (INT32) wsptr[4]; 2441 z4 = (INT32) wsptr[6]; 2442 2443 tmp10 = MULTIPLY(z4, FIX(0.437016024)); /* c12 */ 2444 tmp11 = MULTIPLY(z4, FIX(1.144122806)); /* c6 */ 2445 2446 tmp12 = z1 - tmp10; 2447 tmp13 = z1 + tmp11; 2448 z1 -= (tmp11 - tmp10) << 1; /* c0 = (c6-c12)*2 */ 2449 2450 z4 = z2 - z3; 2451 z3 += z2; 2452 tmp10 = MULTIPLY(z3, FIX(1.337628990)); /* (c2+c4)/2 */ 2453 tmp11 = MULTIPLY(z4, FIX(0.045680613)); /* (c2-c4)/2 */ 2454 z2 = MULTIPLY(z2, FIX(1.439773946)); /* c4+c14 */ 2455 2456 tmp20 = tmp13 + tmp10 + tmp11; 2457 tmp23 = tmp12 - tmp10 + tmp11 + z2; 2458 2459 tmp10 = MULTIPLY(z3, FIX(0.547059574)); /* (c8+c14)/2 */ 2460 tmp11 = MULTIPLY(z4, FIX(0.399234004)); /* (c8-c14)/2 */ 2461 2462 tmp25 = tmp13 - tmp10 - tmp11; 2463 tmp26 = tmp12 + tmp10 - tmp11 - z2; 2464 2465 tmp10 = MULTIPLY(z3, FIX(0.790569415)); /* (c6+c12)/2 */ 2466 tmp11 = MULTIPLY(z4, FIX(0.353553391)); /* (c6-c12)/2 */ 2467 2468 tmp21 = tmp12 + tmp10 + tmp11; 2469 tmp24 = tmp13 - tmp10 + tmp11; 2470 tmp11 += tmp11; 2471 tmp22 = z1 + tmp11; /* c10 = c6-c12 */ 2472 tmp27 = z1 - tmp11 - tmp11; /* c0 = (c6-c12)*2 */ 2473 2474 /* Odd part */ 2475 2476 z1 = (INT32) wsptr[1]; 2477 z2 = (INT32) wsptr[3]; 2478 z4 = (INT32) wsptr[5]; 2479 z3 = MULTIPLY(z4, FIX(1.224744871)); /* c5 */ 2480 z4 = (INT32) wsptr[7]; 2481 2482 tmp13 = z2 - z4; 2483 tmp15 = MULTIPLY(z1 + tmp13, FIX(0.831253876)); /* c9 */ 2484 tmp11 = tmp15 + MULTIPLY(z1, FIX(0.513743148)); /* c3-c9 */ 2485 tmp14 = tmp15 - MULTIPLY(tmp13, FIX(2.176250899)); /* c3+c9 */ 2486 2487 tmp13 = MULTIPLY(z2, - FIX(0.831253876)); /* -c9 */ 2488 tmp15 = MULTIPLY(z2, - FIX(1.344997024)); /* -c3 */ 2489 z2 = z1 - z4; 2490 tmp12 = z3 + MULTIPLY(z2, FIX(1.406466353)); /* c1 */ 2491 2492 tmp10 = tmp12 + MULTIPLY(z4, FIX(2.457431844)) - tmp15; /* c1+c7 */ 2493 tmp16 = tmp12 - MULTIPLY(z1, FIX(1.112434820)) + tmp13; /* c1-c13 */ 2494 tmp12 = MULTIPLY(z2, FIX(1.224744871)) - z3; /* c5 */ 2495 z2 = MULTIPLY(z1 + z4, FIX(0.575212477)); /* c11 */ 2496 tmp13 += z2 + MULTIPLY(z1, FIX(0.475753014)) - z3; /* c7-c11 */ 2497 tmp15 += z2 - MULTIPLY(z4, FIX(0.869244010)) + z3; /* c11+c13 */ 2498 2499 /* Final output stage */ 2500 2501 outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp20 + tmp10, 2502 CONST_BITS+PASS1_BITS+3) 2503 & RANGE_MASK]; 2504 outptr[14] = range_limit[(int) RIGHT_SHIFT(tmp20 - tmp10, 2505 CONST_BITS+PASS1_BITS+3) 2506 & RANGE_MASK]; 2507 outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp21 + tmp11, 2508 CONST_BITS+PASS1_BITS+3) 2509 & RANGE_MASK]; 2510 outptr[13] = range_limit[(int) RIGHT_SHIFT(tmp21 - tmp11, 2511 CONST_BITS+PASS1_BITS+3) 2512 & RANGE_MASK]; 2513 outptr[2] = range_limit[(int) RIGHT_SHIFT(tmp22 + tmp12, 2514 CONST_BITS+PASS1_BITS+3) 2515 & RANGE_MASK]; 2516 outptr[12] = range_limit[(int) RIGHT_SHIFT(tmp22 - tmp12, 2517 CONST_BITS+PASS1_BITS+3) 2518 & RANGE_MASK]; 2519 outptr[3] = range_limit[(int) RIGHT_SHIFT(tmp23 + tmp13, 2520 CONST_BITS+PASS1_BITS+3) 2521 & RANGE_MASK]; 2522 outptr[11] = range_limit[(int) RIGHT_SHIFT(tmp23 - tmp13, 2523 CONST_BITS+PASS1_BITS+3) 2524 & RANGE_MASK]; 2525 outptr[4] = range_limit[(int) RIGHT_SHIFT(tmp24 + tmp14, 2526 CONST_BITS+PASS1_BITS+3) 2527 & RANGE_MASK]; 2528 outptr[10] = range_limit[(int) RIGHT_SHIFT(tmp24 - tmp14, 2529 CONST_BITS+PASS1_BITS+3) 2530 & RANGE_MASK]; 2531 outptr[5] = range_limit[(int) RIGHT_SHIFT(tmp25 + tmp15, 2532 CONST_BITS+PASS1_BITS+3) 2533 & RANGE_MASK]; 2534 outptr[9] = range_limit[(int) RIGHT_SHIFT(tmp25 - tmp15, 2535 CONST_BITS+PASS1_BITS+3) 2536 & RANGE_MASK]; 2537 outptr[6] = range_limit[(int) RIGHT_SHIFT(tmp26 + tmp16, 2538 CONST_BITS+PASS1_BITS+3) 2539 & RANGE_MASK]; 2540 outptr[8] = range_limit[(int) RIGHT_SHIFT(tmp26 - tmp16, 2541 CONST_BITS+PASS1_BITS+3) 2542 & RANGE_MASK]; 2543 outptr[7] = range_limit[(int) RIGHT_SHIFT(tmp27, 2544 CONST_BITS+PASS1_BITS+3) 2545 & RANGE_MASK]; 2546 2547 wsptr += 8; /* advance pointer to next row */ 2548 } 2549 } 2550 2551 2552 /* 2553 * Perform dequantization and inverse DCT on one block of coefficients, 2554 * producing a 16x16 output block. 2555 * 2556 * Optimized algorithm with 28 multiplications in the 1-D kernel. 2557 * cK represents sqrt(2) * cos(K*pi/32). 2558 */ 2559 2560 GLOBAL(void) 2561 jpeg_idct_16x16 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 2562 JCOEFPTR coef_block, 2563 JSAMPARRAY output_buf, JDIMENSION output_col) 2564 { 2565 INT32 tmp0, tmp1, tmp2, tmp3, tmp10, tmp11, tmp12, tmp13; 2566 INT32 tmp20, tmp21, tmp22, tmp23, tmp24, tmp25, tmp26, tmp27; 2567 INT32 z1, z2, z3, z4; 2568 JCOEFPTR inptr; 2569 ISLOW_MULT_TYPE * quantptr; 2570 int * wsptr; 2571 JSAMPROW outptr; 2572 JSAMPLE *range_limit = IDCT_range_limit(cinfo); 2573 int ctr; 2574 int workspace[8*16]; /* buffers data between passes */ 2575 SHIFT_TEMPS 2576 2577 /* Pass 1: process columns from input, store into work array. */ 2578 2579 inptr = coef_block; 2580 quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 2581 wsptr = workspace; 2582 for (ctr = 0; ctr < 8; ctr++, inptr++, quantptr++, wsptr++) { 2583 /* Even part */ 2584 2585 tmp0 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); 2586 tmp0 <<= CONST_BITS; 2587 /* Add fudge factor here for final descale. */ 2588 tmp0 += 1 << (CONST_BITS-PASS1_BITS-1); 2589 2590 z1 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]); 2591 tmp1 = MULTIPLY(z1, FIX(1.306562965)); /* c4[16] = c2[8] */ 2592 tmp2 = MULTIPLY(z1, FIX_0_541196100); /* c12[16] = c6[8] */ 2593 2594 tmp10 = tmp0 + tmp1; 2595 tmp11 = tmp0 - tmp1; 2596 tmp12 = tmp0 + tmp2; 2597 tmp13 = tmp0 - tmp2; 2598 2599 z1 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]); 2600 z2 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]); 2601 z3 = z1 - z2; 2602 z4 = MULTIPLY(z3, FIX(0.275899379)); /* c14[16] = c7[8] */ 2603 z3 = MULTIPLY(z3, FIX(1.387039845)); /* c2[16] = c1[8] */ 2604 2605 tmp0 = z3 + MULTIPLY(z2, FIX_2_562915447); /* (c6+c2)[16] = (c3+c1)[8] */ 2606 tmp1 = z4 + MULTIPLY(z1, FIX_0_899976223); /* (c6-c14)[16] = (c3-c7)[8] */ 2607 tmp2 = z3 - MULTIPLY(z1, FIX(0.601344887)); /* (c2-c10)[16] = (c1-c5)[8] */ 2608 tmp3 = z4 - MULTIPLY(z2, FIX(0.509795579)); /* (c10-c14)[16] = (c5-c7)[8] */ 2609 2610 tmp20 = tmp10 + tmp0; 2611 tmp27 = tmp10 - tmp0; 2612 tmp21 = tmp12 + tmp1; 2613 tmp26 = tmp12 - tmp1; 2614 tmp22 = tmp13 + tmp2; 2615 tmp25 = tmp13 - tmp2; 2616 tmp23 = tmp11 + tmp3; 2617 tmp24 = tmp11 - tmp3; 2618 2619 /* Odd part */ 2620 2621 z1 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); 2622 z2 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]); 2623 z3 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]); 2624 z4 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]); 2625 2626 tmp11 = z1 + z3; 2627 2628 tmp1 = MULTIPLY(z1 + z2, FIX(1.353318001)); /* c3 */ 2629 tmp2 = MULTIPLY(tmp11, FIX(1.247225013)); /* c5 */ 2630 tmp3 = MULTIPLY(z1 + z4, FIX(1.093201867)); /* c7 */ 2631 tmp10 = MULTIPLY(z1 - z4, FIX(0.897167586)); /* c9 */ 2632 tmp11 = MULTIPLY(tmp11, FIX(0.666655658)); /* c11 */ 2633 tmp12 = MULTIPLY(z1 - z2, FIX(0.410524528)); /* c13 */ 2634 tmp0 = tmp1 + tmp2 + tmp3 - 2635 MULTIPLY(z1, FIX(2.286341144)); /* c7+c5+c3-c1 */ 2636 tmp13 = tmp10 + tmp11 + tmp12 - 2637 MULTIPLY(z1, FIX(1.835730603)); /* c9+c11+c13-c15 */ 2638 z1 = MULTIPLY(z2 + z3, FIX(0.138617169)); /* c15 */ 2639 tmp1 += z1 + MULTIPLY(z2, FIX(0.071888074)); /* c9+c11-c3-c15 */ 2640 tmp2 += z1 - MULTIPLY(z3, FIX(1.125726048)); /* c5+c7+c15-c3 */ 2641 z1 = MULTIPLY(z3 - z2, FIX(1.407403738)); /* c1 */ 2642 tmp11 += z1 - MULTIPLY(z3, FIX(0.766367282)); /* c1+c11-c9-c13 */ 2643 tmp12 += z1 + MULTIPLY(z2, FIX(1.971951411)); /* c1+c5+c13-c7 */ 2644 z2 += z4; 2645 z1 = MULTIPLY(z2, - FIX(0.666655658)); /* -c11 */ 2646 tmp1 += z1; 2647 tmp3 += z1 + MULTIPLY(z4, FIX(1.065388962)); /* c3+c11+c15-c7 */ 2648 z2 = MULTIPLY(z2, - FIX(1.247225013)); /* -c5 */ 2649 tmp10 += z2 + MULTIPLY(z4, FIX(3.141271809)); /* c1+c5+c9-c13 */ 2650 tmp12 += z2; 2651 z2 = MULTIPLY(z3 + z4, - FIX(1.353318001)); /* -c3 */ 2652 tmp2 += z2; 2653 tmp3 += z2; 2654 z2 = MULTIPLY(z4 - z3, FIX(0.410524528)); /* c13 */ 2655 tmp10 += z2; 2656 tmp11 += z2; 2657 2658 /* Final output stage */ 2659 2660 wsptr[8*0] = (int) RIGHT_SHIFT(tmp20 + tmp0, CONST_BITS-PASS1_BITS); 2661 wsptr[8*15] = (int) RIGHT_SHIFT(tmp20 - tmp0, CONST_BITS-PASS1_BITS); 2662 wsptr[8*1] = (int) RIGHT_SHIFT(tmp21 + tmp1, CONST_BITS-PASS1_BITS); 2663 wsptr[8*14] = (int) RIGHT_SHIFT(tmp21 - tmp1, CONST_BITS-PASS1_BITS); 2664 wsptr[8*2] = (int) RIGHT_SHIFT(tmp22 + tmp2, CONST_BITS-PASS1_BITS); 2665 wsptr[8*13] = (int) RIGHT_SHIFT(tmp22 - tmp2, CONST_BITS-PASS1_BITS); 2666 wsptr[8*3] = (int) RIGHT_SHIFT(tmp23 + tmp3, CONST_BITS-PASS1_BITS); 2667 wsptr[8*12] = (int) RIGHT_SHIFT(tmp23 - tmp3, CONST_BITS-PASS1_BITS); 2668 wsptr[8*4] = (int) RIGHT_SHIFT(tmp24 + tmp10, CONST_BITS-PASS1_BITS); 2669 wsptr[8*11] = (int) RIGHT_SHIFT(tmp24 - tmp10, CONST_BITS-PASS1_BITS); 2670 wsptr[8*5] = (int) RIGHT_SHIFT(tmp25 + tmp11, CONST_BITS-PASS1_BITS); 2671 wsptr[8*10] = (int) RIGHT_SHIFT(tmp25 - tmp11, CONST_BITS-PASS1_BITS); 2672 wsptr[8*6] = (int) RIGHT_SHIFT(tmp26 + tmp12, CONST_BITS-PASS1_BITS); 2673 wsptr[8*9] = (int) RIGHT_SHIFT(tmp26 - tmp12, CONST_BITS-PASS1_BITS); 2674 wsptr[8*7] = (int) RIGHT_SHIFT(tmp27 + tmp13, CONST_BITS-PASS1_BITS); 2675 wsptr[8*8] = (int) RIGHT_SHIFT(tmp27 - tmp13, CONST_BITS-PASS1_BITS); 2676 } 2677 2678 /* Pass 2: process 16 rows from work array, store into output array. */ 2679 2680 wsptr = workspace; 2681 for (ctr = 0; ctr < 16; ctr++) { 2682 outptr = output_buf[ctr] + output_col; 2683 2684 /* Even part */ 2685 2686 /* Add fudge factor here for final descale. */ 2687 tmp0 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2)); 2688 tmp0 <<= CONST_BITS; 2689 2690 z1 = (INT32) wsptr[4]; 2691 tmp1 = MULTIPLY(z1, FIX(1.306562965)); /* c4[16] = c2[8] */ 2692 tmp2 = MULTIPLY(z1, FIX_0_541196100); /* c12[16] = c6[8] */ 2693 2694 tmp10 = tmp0 + tmp1; 2695 tmp11 = tmp0 - tmp1; 2696 tmp12 = tmp0 + tmp2; 2697 tmp13 = tmp0 - tmp2; 2698 2699 z1 = (INT32) wsptr[2]; 2700 z2 = (INT32) wsptr[6]; 2701 z3 = z1 - z2; 2702 z4 = MULTIPLY(z3, FIX(0.275899379)); /* c14[16] = c7[8] */ 2703 z3 = MULTIPLY(z3, FIX(1.387039845)); /* c2[16] = c1[8] */ 2704 2705 tmp0 = z3 + MULTIPLY(z2, FIX_2_562915447); /* (c6+c2)[16] = (c3+c1)[8] */ 2706 tmp1 = z4 + MULTIPLY(z1, FIX_0_899976223); /* (c6-c14)[16] = (c3-c7)[8] */ 2707 tmp2 = z3 - MULTIPLY(z1, FIX(0.601344887)); /* (c2-c10)[16] = (c1-c5)[8] */ 2708 tmp3 = z4 - MULTIPLY(z2, FIX(0.509795579)); /* (c10-c14)[16] = (c5-c7)[8] */ 2709 2710 tmp20 = tmp10 + tmp0; 2711 tmp27 = tmp10 - tmp0; 2712 tmp21 = tmp12 + tmp1; 2713 tmp26 = tmp12 - tmp1; 2714 tmp22 = tmp13 + tmp2; 2715 tmp25 = tmp13 - tmp2; 2716 tmp23 = tmp11 + tmp3; 2717 tmp24 = tmp11 - tmp3; 2718 2719 /* Odd part */ 2720 2721 z1 = (INT32) wsptr[1]; 2722 z2 = (INT32) wsptr[3]; 2723 z3 = (INT32) wsptr[5]; 2724 z4 = (INT32) wsptr[7]; 2725 2726 tmp11 = z1 + z3; 2727 2728 tmp1 = MULTIPLY(z1 + z2, FIX(1.353318001)); /* c3 */ 2729 tmp2 = MULTIPLY(tmp11, FIX(1.247225013)); /* c5 */ 2730 tmp3 = MULTIPLY(z1 + z4, FIX(1.093201867)); /* c7 */ 2731 tmp10 = MULTIPLY(z1 - z4, FIX(0.897167586)); /* c9 */ 2732 tmp11 = MULTIPLY(tmp11, FIX(0.666655658)); /* c11 */ 2733 tmp12 = MULTIPLY(z1 - z2, FIX(0.410524528)); /* c13 */ 2734 tmp0 = tmp1 + tmp2 + tmp3 - 2735 MULTIPLY(z1, FIX(2.286341144)); /* c7+c5+c3-c1 */ 2736 tmp13 = tmp10 + tmp11 + tmp12 - 2737 MULTIPLY(z1, FIX(1.835730603)); /* c9+c11+c13-c15 */ 2738 z1 = MULTIPLY(z2 + z3, FIX(0.138617169)); /* c15 */ 2739 tmp1 += z1 + MULTIPLY(z2, FIX(0.071888074)); /* c9+c11-c3-c15 */ 2740 tmp2 += z1 - MULTIPLY(z3, FIX(1.125726048)); /* c5+c7+c15-c3 */ 2741 z1 = MULTIPLY(z3 - z2, FIX(1.407403738)); /* c1 */ 2742 tmp11 += z1 - MULTIPLY(z3, FIX(0.766367282)); /* c1+c11-c9-c13 */ 2743 tmp12 += z1 + MULTIPLY(z2, FIX(1.971951411)); /* c1+c5+c13-c7 */ 2744 z2 += z4; 2745 z1 = MULTIPLY(z2, - FIX(0.666655658)); /* -c11 */ 2746 tmp1 += z1; 2747 tmp3 += z1 + MULTIPLY(z4, FIX(1.065388962)); /* c3+c11+c15-c7 */ 2748 z2 = MULTIPLY(z2, - FIX(1.247225013)); /* -c5 */ 2749 tmp10 += z2 + MULTIPLY(z4, FIX(3.141271809)); /* c1+c5+c9-c13 */ 2750 tmp12 += z2; 2751 z2 = MULTIPLY(z3 + z4, - FIX(1.353318001)); /* -c3 */ 2752 tmp2 += z2; 2753 tmp3 += z2; 2754 z2 = MULTIPLY(z4 - z3, FIX(0.410524528)); /* c13 */ 2755 tmp10 += z2; 2756 tmp11 += z2; 2757 2758 /* Final output stage */ 2759 2760 outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp20 + tmp0, 2761 CONST_BITS+PASS1_BITS+3) 2762 & RANGE_MASK]; 2763 outptr[15] = range_limit[(int) RIGHT_SHIFT(tmp20 - tmp0, 2764 CONST_BITS+PASS1_BITS+3) 2765 & RANGE_MASK]; 2766 outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp21 + tmp1, 2767 CONST_BITS+PASS1_BITS+3) 2768 & RANGE_MASK]; 2769 outptr[14] = range_limit[(int) RIGHT_SHIFT(tmp21 - tmp1, 2770 CONST_BITS+PASS1_BITS+3) 2771 & RANGE_MASK]; 2772 outptr[2] = range_limit[(int) RIGHT_SHIFT(tmp22 + tmp2, 2773 CONST_BITS+PASS1_BITS+3) 2774 & RANGE_MASK]; 2775 outptr[13] = range_limit[(int) RIGHT_SHIFT(tmp22 - tmp2, 2776 CONST_BITS+PASS1_BITS+3) 2777 & RANGE_MASK]; 2778 outptr[3] = range_limit[(int) RIGHT_SHIFT(tmp23 + tmp3, 2779 CONST_BITS+PASS1_BITS+3) 2780 & RANGE_MASK]; 2781 outptr[12] = range_limit[(int) RIGHT_SHIFT(tmp23 - tmp3, 2782 CONST_BITS+PASS1_BITS+3) 2783 & RANGE_MASK]; 2784 outptr[4] = range_limit[(int) RIGHT_SHIFT(tmp24 + tmp10, 2785 CONST_BITS+PASS1_BITS+3) 2786 & RANGE_MASK]; 2787 outptr[11] = range_limit[(int) RIGHT_SHIFT(tmp24 - tmp10, 2788 CONST_BITS+PASS1_BITS+3) 2789 & RANGE_MASK]; 2790 outptr[5] = range_limit[(int) RIGHT_SHIFT(tmp25 + tmp11, 2791 CONST_BITS+PASS1_BITS+3) 2792 & RANGE_MASK]; 2793 outptr[10] = range_limit[(int) RIGHT_SHIFT(tmp25 - tmp11, 2794 CONST_BITS+PASS1_BITS+3) 2795 & RANGE_MASK]; 2796 outptr[6] = range_limit[(int) RIGHT_SHIFT(tmp26 + tmp12, 2797 CONST_BITS+PASS1_BITS+3) 2798 & RANGE_MASK]; 2799 outptr[9] = range_limit[(int) RIGHT_SHIFT(tmp26 - tmp12, 2800 CONST_BITS+PASS1_BITS+3) 2801 & RANGE_MASK]; 2802 outptr[7] = range_limit[(int) RIGHT_SHIFT(tmp27 + tmp13, 2803 CONST_BITS+PASS1_BITS+3) 2804 & RANGE_MASK]; 2805 outptr[8] = range_limit[(int) RIGHT_SHIFT(tmp27 - tmp13, 2806 CONST_BITS+PASS1_BITS+3) 2807 & RANGE_MASK]; 2808 2809 wsptr += 8; /* advance pointer to next row */ 2810 } 2811 } 2812 2813 2814 /* 2815 * Perform dequantization and inverse DCT on one block of coefficients, 2816 * producing a 16x8 output block. 2817 * 2818 * 8-point IDCT in pass 1 (columns), 16-point in pass 2 (rows). 2819 */ 2820 2821 GLOBAL(void) 2822 jpeg_idct_16x8 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 2823 JCOEFPTR coef_block, 2824 JSAMPARRAY output_buf, JDIMENSION output_col) 2825 { 2826 INT32 tmp0, tmp1, tmp2, tmp3, tmp10, tmp11, tmp12, tmp13; 2827 INT32 tmp20, tmp21, tmp22, tmp23, tmp24, tmp25, tmp26, tmp27; 2828 INT32 z1, z2, z3, z4; 2829 JCOEFPTR inptr; 2830 ISLOW_MULT_TYPE * quantptr; 2831 int * wsptr; 2832 JSAMPROW outptr; 2833 JSAMPLE *range_limit = IDCT_range_limit(cinfo); 2834 int ctr; 2835 int workspace[8*8]; /* buffers data between passes */ 2836 SHIFT_TEMPS 2837 2838 /* Pass 1: process columns from input, store into work array. */ 2839 /* Note results are scaled up by sqrt(8) compared to a true IDCT; */ 2840 /* furthermore, we scale the results by 2**PASS1_BITS. */ 2841 2842 inptr = coef_block; 2843 quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 2844 wsptr = workspace; 2845 for (ctr = DCTSIZE; ctr > 0; ctr--) { 2846 /* Due to quantization, we will usually find that many of the input 2847 * coefficients are zero, especially the AC terms. We can exploit this 2848 * by short-circuiting the IDCT calculation for any column in which all 2849 * the AC terms are zero. In that case each output is equal to the 2850 * DC coefficient (with scale factor as needed). 2851 * With typical images and quantization tables, half or more of the 2852 * column DCT calculations can be simplified this way. 2853 */ 2854 2855 if (inptr[DCTSIZE*1] == 0 && inptr[DCTSIZE*2] == 0 && 2856 inptr[DCTSIZE*3] == 0 && inptr[DCTSIZE*4] == 0 && 2857 inptr[DCTSIZE*5] == 0 && inptr[DCTSIZE*6] == 0 && 2858 inptr[DCTSIZE*7] == 0) { 2859 /* AC terms all zero */ 2860 int dcval = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]) << PASS1_BITS; 2861 2862 wsptr[DCTSIZE*0] = dcval; 2863 wsptr[DCTSIZE*1] = dcval; 2864 wsptr[DCTSIZE*2] = dcval; 2865 wsptr[DCTSIZE*3] = dcval; 2866 wsptr[DCTSIZE*4] = dcval; 2867 wsptr[DCTSIZE*5] = dcval; 2868 wsptr[DCTSIZE*6] = dcval; 2869 wsptr[DCTSIZE*7] = dcval; 2870 2871 inptr++; /* advance pointers to next column */ 2872 quantptr++; 2873 wsptr++; 2874 continue; 2875 } 2876 2877 /* Even part: reverse the even part of the forward DCT. */ 2878 /* The rotator is sqrt(2)*c(-6). */ 2879 2880 z2 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]); 2881 z3 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]); 2882 2883 z1 = MULTIPLY(z2 + z3, FIX_0_541196100); 2884 tmp2 = z1 + MULTIPLY(z2, FIX_0_765366865); 2885 tmp3 = z1 - MULTIPLY(z3, FIX_1_847759065); 2886 2887 z2 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); 2888 z3 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]); 2889 z2 <<= CONST_BITS; 2890 z3 <<= CONST_BITS; 2891 /* Add fudge factor here for final descale. */ 2892 z2 += ONE << (CONST_BITS-PASS1_BITS-1); 2893 2894 tmp0 = z2 + z3; 2895 tmp1 = z2 - z3; 2896 2897 tmp10 = tmp0 + tmp2; 2898 tmp13 = tmp0 - tmp2; 2899 tmp11 = tmp1 + tmp3; 2900 tmp12 = tmp1 - tmp3; 2901 2902 /* Odd part per figure 8; the matrix is unitary and hence its 2903 * transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively. 2904 */ 2905 2906 tmp0 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]); 2907 tmp1 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]); 2908 tmp2 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]); 2909 tmp3 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); 2910 2911 z2 = tmp0 + tmp2; 2912 z3 = tmp1 + tmp3; 2913 2914 z1 = MULTIPLY(z2 + z3, FIX_1_175875602); /* sqrt(2) * c3 */ 2915 z2 = MULTIPLY(z2, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */ 2916 z3 = MULTIPLY(z3, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */ 2917 z2 += z1; 2918 z3 += z1; 2919 2920 z1 = MULTIPLY(tmp0 + tmp3, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */ 2921 tmp0 = MULTIPLY(tmp0, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */ 2922 tmp3 = MULTIPLY(tmp3, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */ 2923 tmp0 += z1 + z2; 2924 tmp3 += z1 + z3; 2925 2926 z1 = MULTIPLY(tmp1 + tmp2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */ 2927 tmp1 = MULTIPLY(tmp1, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */ 2928 tmp2 = MULTIPLY(tmp2, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */ 2929 tmp1 += z1 + z3; 2930 tmp2 += z1 + z2; 2931 2932 /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */ 2933 2934 wsptr[DCTSIZE*0] = (int) RIGHT_SHIFT(tmp10 + tmp3, CONST_BITS-PASS1_BITS); 2935 wsptr[DCTSIZE*7] = (int) RIGHT_SHIFT(tmp10 - tmp3, CONST_BITS-PASS1_BITS); 2936 wsptr[DCTSIZE*1] = (int) RIGHT_SHIFT(tmp11 + tmp2, CONST_BITS-PASS1_BITS); 2937 wsptr[DCTSIZE*6] = (int) RIGHT_SHIFT(tmp11 - tmp2, CONST_BITS-PASS1_BITS); 2938 wsptr[DCTSIZE*2] = (int) RIGHT_SHIFT(tmp12 + tmp1, CONST_BITS-PASS1_BITS); 2939 wsptr[DCTSIZE*5] = (int) RIGHT_SHIFT(tmp12 - tmp1, CONST_BITS-PASS1_BITS); 2940 wsptr[DCTSIZE*3] = (int) RIGHT_SHIFT(tmp13 + tmp0, CONST_BITS-PASS1_BITS); 2941 wsptr[DCTSIZE*4] = (int) RIGHT_SHIFT(tmp13 - tmp0, CONST_BITS-PASS1_BITS); 2942 2943 inptr++; /* advance pointers to next column */ 2944 quantptr++; 2945 wsptr++; 2946 } 2947 2948 /* Pass 2: process 8 rows from work array, store into output array. 2949 * 16-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/32). 2950 */ 2951 wsptr = workspace; 2952 for (ctr = 0; ctr < 8; ctr++) { 2953 outptr = output_buf[ctr] + output_col; 2954 2955 /* Even part */ 2956 2957 /* Add fudge factor here for final descale. */ 2958 tmp0 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2)); 2959 tmp0 <<= CONST_BITS; 2960 2961 z1 = (INT32) wsptr[4]; 2962 tmp1 = MULTIPLY(z1, FIX(1.306562965)); /* c4[16] = c2[8] */ 2963 tmp2 = MULTIPLY(z1, FIX_0_541196100); /* c12[16] = c6[8] */ 2964 2965 tmp10 = tmp0 + tmp1; 2966 tmp11 = tmp0 - tmp1; 2967 tmp12 = tmp0 + tmp2; 2968 tmp13 = tmp0 - tmp2; 2969 2970 z1 = (INT32) wsptr[2]; 2971 z2 = (INT32) wsptr[6]; 2972 z3 = z1 - z2; 2973 z4 = MULTIPLY(z3, FIX(0.275899379)); /* c14[16] = c7[8] */ 2974 z3 = MULTIPLY(z3, FIX(1.387039845)); /* c2[16] = c1[8] */ 2975 2976 tmp0 = z3 + MULTIPLY(z2, FIX_2_562915447); /* (c6+c2)[16] = (c3+c1)[8] */ 2977 tmp1 = z4 + MULTIPLY(z1, FIX_0_899976223); /* (c6-c14)[16] = (c3-c7)[8] */ 2978 tmp2 = z3 - MULTIPLY(z1, FIX(0.601344887)); /* (c2-c10)[16] = (c1-c5)[8] */ 2979 tmp3 = z4 - MULTIPLY(z2, FIX(0.509795579)); /* (c10-c14)[16] = (c5-c7)[8] */ 2980 2981 tmp20 = tmp10 + tmp0; 2982 tmp27 = tmp10 - tmp0; 2983 tmp21 = tmp12 + tmp1; 2984 tmp26 = tmp12 - tmp1; 2985 tmp22 = tmp13 + tmp2; 2986 tmp25 = tmp13 - tmp2; 2987 tmp23 = tmp11 + tmp3; 2988 tmp24 = tmp11 - tmp3; 2989 2990 /* Odd part */ 2991 2992 z1 = (INT32) wsptr[1]; 2993 z2 = (INT32) wsptr[3]; 2994 z3 = (INT32) wsptr[5]; 2995 z4 = (INT32) wsptr[7]; 2996 2997 tmp11 = z1 + z3; 2998 2999 tmp1 = MULTIPLY(z1 + z2, FIX(1.353318001)); /* c3 */ 3000 tmp2 = MULTIPLY(tmp11, FIX(1.247225013)); /* c5 */ 3001 tmp3 = MULTIPLY(z1 + z4, FIX(1.093201867)); /* c7 */ 3002 tmp10 = MULTIPLY(z1 - z4, FIX(0.897167586)); /* c9 */ 3003 tmp11 = MULTIPLY(tmp11, FIX(0.666655658)); /* c11 */ 3004 tmp12 = MULTIPLY(z1 - z2, FIX(0.410524528)); /* c13 */ 3005 tmp0 = tmp1 + tmp2 + tmp3 - 3006 MULTIPLY(z1, FIX(2.286341144)); /* c7+c5+c3-c1 */ 3007 tmp13 = tmp10 + tmp11 + tmp12 - 3008 MULTIPLY(z1, FIX(1.835730603)); /* c9+c11+c13-c15 */ 3009 z1 = MULTIPLY(z2 + z3, FIX(0.138617169)); /* c15 */ 3010 tmp1 += z1 + MULTIPLY(z2, FIX(0.071888074)); /* c9+c11-c3-c15 */ 3011 tmp2 += z1 - MULTIPLY(z3, FIX(1.125726048)); /* c5+c7+c15-c3 */ 3012 z1 = MULTIPLY(z3 - z2, FIX(1.407403738)); /* c1 */ 3013 tmp11 += z1 - MULTIPLY(z3, FIX(0.766367282)); /* c1+c11-c9-c13 */ 3014 tmp12 += z1 + MULTIPLY(z2, FIX(1.971951411)); /* c1+c5+c13-c7 */ 3015 z2 += z4; 3016 z1 = MULTIPLY(z2, - FIX(0.666655658)); /* -c11 */ 3017 tmp1 += z1; 3018 tmp3 += z1 + MULTIPLY(z4, FIX(1.065388962)); /* c3+c11+c15-c7 */ 3019 z2 = MULTIPLY(z2, - FIX(1.247225013)); /* -c5 */ 3020 tmp10 += z2 + MULTIPLY(z4, FIX(3.141271809)); /* c1+c5+c9-c13 */ 3021 tmp12 += z2; 3022 z2 = MULTIPLY(z3 + z4, - FIX(1.353318001)); /* -c3 */ 3023 tmp2 += z2; 3024 tmp3 += z2; 3025 z2 = MULTIPLY(z4 - z3, FIX(0.410524528)); /* c13 */ 3026 tmp10 += z2; 3027 tmp11 += z2; 3028 3029 /* Final output stage */ 3030 3031 outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp20 + tmp0, 3032 CONST_BITS+PASS1_BITS+3) 3033 & RANGE_MASK]; 3034 outptr[15] = range_limit[(int) RIGHT_SHIFT(tmp20 - tmp0, 3035 CONST_BITS+PASS1_BITS+3) 3036 & RANGE_MASK]; 3037 outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp21 + tmp1, 3038 CONST_BITS+PASS1_BITS+3) 3039 & RANGE_MASK]; 3040 outptr[14] = range_limit[(int) RIGHT_SHIFT(tmp21 - tmp1, 3041 CONST_BITS+PASS1_BITS+3) 3042 & RANGE_MASK]; 3043 outptr[2] = range_limit[(int) RIGHT_SHIFT(tmp22 + tmp2, 3044 CONST_BITS+PASS1_BITS+3) 3045 & RANGE_MASK]; 3046 outptr[13] = range_limit[(int) RIGHT_SHIFT(tmp22 - tmp2, 3047 CONST_BITS+PASS1_BITS+3) 3048 & RANGE_MASK]; 3049 outptr[3] = range_limit[(int) RIGHT_SHIFT(tmp23 + tmp3, 3050 CONST_BITS+PASS1_BITS+3) 3051 & RANGE_MASK]; 3052 outptr[12] = range_limit[(int) RIGHT_SHIFT(tmp23 - tmp3, 3053 CONST_BITS+PASS1_BITS+3) 3054 & RANGE_MASK]; 3055 outptr[4] = range_limit[(int) RIGHT_SHIFT(tmp24 + tmp10, 3056 CONST_BITS+PASS1_BITS+3) 3057 & RANGE_MASK]; 3058 outptr[11] = range_limit[(int) RIGHT_SHIFT(tmp24 - tmp10, 3059 CONST_BITS+PASS1_BITS+3) 3060 & RANGE_MASK]; 3061 outptr[5] = range_limit[(int) RIGHT_SHIFT(tmp25 + tmp11, 3062 CONST_BITS+PASS1_BITS+3) 3063 & RANGE_MASK]; 3064 outptr[10] = range_limit[(int) RIGHT_SHIFT(tmp25 - tmp11, 3065 CONST_BITS+PASS1_BITS+3) 3066 & RANGE_MASK]; 3067 outptr[6] = range_limit[(int) RIGHT_SHIFT(tmp26 + tmp12, 3068 CONST_BITS+PASS1_BITS+3) 3069 & RANGE_MASK]; 3070 outptr[9] = range_limit[(int) RIGHT_SHIFT(tmp26 - tmp12, 3071 CONST_BITS+PASS1_BITS+3) 3072 & RANGE_MASK]; 3073 outptr[7] = range_limit[(int) RIGHT_SHIFT(tmp27 + tmp13, 3074 CONST_BITS+PASS1_BITS+3) 3075 & RANGE_MASK]; 3076 outptr[8] = range_limit[(int) RIGHT_SHIFT(tmp27 - tmp13, 3077 CONST_BITS+PASS1_BITS+3) 3078 & RANGE_MASK]; 3079 3080 wsptr += 8; /* advance pointer to next row */ 3081 } 3082 } 3083 3084 3085 /* 3086 * Perform dequantization and inverse DCT on one block of coefficients, 3087 * producing a 14x7 output block. 3088 * 3089 * 7-point IDCT in pass 1 (columns), 14-point in pass 2 (rows). 3090 */ 3091 3092 GLOBAL(void) 3093 jpeg_idct_14x7 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 3094 JCOEFPTR coef_block, 3095 JSAMPARRAY output_buf, JDIMENSION output_col) 3096 { 3097 INT32 tmp10, tmp11, tmp12, tmp13, tmp14, tmp15, tmp16; 3098 INT32 tmp20, tmp21, tmp22, tmp23, tmp24, tmp25, tmp26; 3099 INT32 z1, z2, z3, z4; 3100 JCOEFPTR inptr; 3101 ISLOW_MULT_TYPE * quantptr; 3102 int * wsptr; 3103 JSAMPROW outptr; 3104 JSAMPLE *range_limit = IDCT_range_limit(cinfo); 3105 int ctr; 3106 int workspace[8*7]; /* buffers data between passes */ 3107 SHIFT_TEMPS 3108 3109 /* Pass 1: process columns from input, store into work array. 3110 * 7-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/14). 3111 */ 3112 inptr = coef_block; 3113 quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 3114 wsptr = workspace; 3115 for (ctr = 0; ctr < 8; ctr++, inptr++, quantptr++, wsptr++) { 3116 /* Even part */ 3117 3118 tmp23 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); 3119 tmp23 <<= CONST_BITS; 3120 /* Add fudge factor here for final descale. */ 3121 tmp23 += ONE << (CONST_BITS-PASS1_BITS-1); 3122 3123 z1 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]); 3124 z2 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]); 3125 z3 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]); 3126 3127 tmp20 = MULTIPLY(z2 - z3, FIX(0.881747734)); /* c4 */ 3128 tmp22 = MULTIPLY(z1 - z2, FIX(0.314692123)); /* c6 */ 3129 tmp21 = tmp20 + tmp22 + tmp23 - MULTIPLY(z2, FIX(1.841218003)); /* c2+c4-c6 */ 3130 tmp10 = z1 + z3; 3131 z2 -= tmp10; 3132 tmp10 = MULTIPLY(tmp10, FIX(1.274162392)) + tmp23; /* c2 */ 3133 tmp20 += tmp10 - MULTIPLY(z3, FIX(0.077722536)); /* c2-c4-c6 */ 3134 tmp22 += tmp10 - MULTIPLY(z1, FIX(2.470602249)); /* c2+c4+c6 */ 3135 tmp23 += MULTIPLY(z2, FIX(1.414213562)); /* c0 */ 3136 3137 /* Odd part */ 3138 3139 z1 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); 3140 z2 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]); 3141 z3 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]); 3142 3143 tmp11 = MULTIPLY(z1 + z2, FIX(0.935414347)); /* (c3+c1-c5)/2 */ 3144 tmp12 = MULTIPLY(z1 - z2, FIX(0.170262339)); /* (c3+c5-c1)/2 */ 3145 tmp10 = tmp11 - tmp12; 3146 tmp11 += tmp12; 3147 tmp12 = MULTIPLY(z2 + z3, - FIX(1.378756276)); /* -c1 */ 3148 tmp11 += tmp12; 3149 z2 = MULTIPLY(z1 + z3, FIX(0.613604268)); /* c5 */ 3150 tmp10 += z2; 3151 tmp12 += z2 + MULTIPLY(z3, FIX(1.870828693)); /* c3+c1-c5 */ 3152 3153 /* Final output stage */ 3154 3155 wsptr[8*0] = (int) RIGHT_SHIFT(tmp20 + tmp10, CONST_BITS-PASS1_BITS); 3156 wsptr[8*6] = (int) RIGHT_SHIFT(tmp20 - tmp10, CONST_BITS-PASS1_BITS); 3157 wsptr[8*1] = (int) RIGHT_SHIFT(tmp21 + tmp11, CONST_BITS-PASS1_BITS); 3158 wsptr[8*5] = (int) RIGHT_SHIFT(tmp21 - tmp11, CONST_BITS-PASS1_BITS); 3159 wsptr[8*2] = (int) RIGHT_SHIFT(tmp22 + tmp12, CONST_BITS-PASS1_BITS); 3160 wsptr[8*4] = (int) RIGHT_SHIFT(tmp22 - tmp12, CONST_BITS-PASS1_BITS); 3161 wsptr[8*3] = (int) RIGHT_SHIFT(tmp23, CONST_BITS-PASS1_BITS); 3162 } 3163 3164 /* Pass 2: process 7 rows from work array, store into output array. 3165 * 14-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/28). 3166 */ 3167 wsptr = workspace; 3168 for (ctr = 0; ctr < 7; ctr++) { 3169 outptr = output_buf[ctr] + output_col; 3170 3171 /* Even part */ 3172 3173 /* Add fudge factor here for final descale. */ 3174 z1 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2)); 3175 z1 <<= CONST_BITS; 3176 z4 = (INT32) wsptr[4]; 3177 z2 = MULTIPLY(z4, FIX(1.274162392)); /* c4 */ 3178 z3 = MULTIPLY(z4, FIX(0.314692123)); /* c12 */ 3179 z4 = MULTIPLY(z4, FIX(0.881747734)); /* c8 */ 3180 3181 tmp10 = z1 + z2; 3182 tmp11 = z1 + z3; 3183 tmp12 = z1 - z4; 3184 3185 tmp23 = z1 - ((z2 + z3 - z4) << 1); /* c0 = (c4+c12-c8)*2 */ 3186 3187 z1 = (INT32) wsptr[2]; 3188 z2 = (INT32) wsptr[6]; 3189 3190 z3 = MULTIPLY(z1 + z2, FIX(1.105676686)); /* c6 */ 3191 3192 tmp13 = z3 + MULTIPLY(z1, FIX(0.273079590)); /* c2-c6 */ 3193 tmp14 = z3 - MULTIPLY(z2, FIX(1.719280954)); /* c6+c10 */ 3194 tmp15 = MULTIPLY(z1, FIX(0.613604268)) - /* c10 */ 3195 MULTIPLY(z2, FIX(1.378756276)); /* c2 */ 3196 3197 tmp20 = tmp10 + tmp13; 3198 tmp26 = tmp10 - tmp13; 3199 tmp21 = tmp11 + tmp14; 3200 tmp25 = tmp11 - tmp14; 3201 tmp22 = tmp12 + tmp15; 3202 tmp24 = tmp12 - tmp15; 3203 3204 /* Odd part */ 3205 3206 z1 = (INT32) wsptr[1]; 3207 z2 = (INT32) wsptr[3]; 3208 z3 = (INT32) wsptr[5]; 3209 z4 = (INT32) wsptr[7]; 3210 z4 <<= CONST_BITS; 3211 3212 tmp14 = z1 + z3; 3213 tmp11 = MULTIPLY(z1 + z2, FIX(1.334852607)); /* c3 */ 3214 tmp12 = MULTIPLY(tmp14, FIX(1.197448846)); /* c5 */ 3215 tmp10 = tmp11 + tmp12 + z4 - MULTIPLY(z1, FIX(1.126980169)); /* c3+c5-c1 */ 3216 tmp14 = MULTIPLY(tmp14, FIX(0.752406978)); /* c9 */ 3217 tmp16 = tmp14 - MULTIPLY(z1, FIX(1.061150426)); /* c9+c11-c13 */ 3218 z1 -= z2; 3219 tmp15 = MULTIPLY(z1, FIX(0.467085129)) - z4; /* c11 */ 3220 tmp16 += tmp15; 3221 tmp13 = MULTIPLY(z2 + z3, - FIX(0.158341681)) - z4; /* -c13 */ 3222 tmp11 += tmp13 - MULTIPLY(z2, FIX(0.424103948)); /* c3-c9-c13 */ 3223 tmp12 += tmp13 - MULTIPLY(z3, FIX(2.373959773)); /* c3+c5-c13 */ 3224 tmp13 = MULTIPLY(z3 - z2, FIX(1.405321284)); /* c1 */ 3225 tmp14 += tmp13 + z4 - MULTIPLY(z3, FIX(1.6906431334)); /* c1+c9-c11 */ 3226 tmp15 += tmp13 + MULTIPLY(z2, FIX(0.674957567)); /* c1+c11-c5 */ 3227 3228 tmp13 = ((z1 - z3) << CONST_BITS) + z4; 3229 3230 /* Final output stage */ 3231 3232 outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp20 + tmp10, 3233 CONST_BITS+PASS1_BITS+3) 3234 & RANGE_MASK]; 3235 outptr[13] = range_limit[(int) RIGHT_SHIFT(tmp20 - tmp10, 3236 CONST_BITS+PASS1_BITS+3) 3237 & RANGE_MASK]; 3238 outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp21 + tmp11, 3239 CONST_BITS+PASS1_BITS+3) 3240 & RANGE_MASK]; 3241 outptr[12] = range_limit[(int) RIGHT_SHIFT(tmp21 - tmp11, 3242 CONST_BITS+PASS1_BITS+3) 3243 & RANGE_MASK]; 3244 outptr[2] = range_limit[(int) RIGHT_SHIFT(tmp22 + tmp12, 3245 CONST_BITS+PASS1_BITS+3) 3246 & RANGE_MASK]; 3247 outptr[11] = range_limit[(int) RIGHT_SHIFT(tmp22 - tmp12, 3248 CONST_BITS+PASS1_BITS+3) 3249 & RANGE_MASK]; 3250 outptr[3] = range_limit[(int) RIGHT_SHIFT(tmp23 + tmp13, 3251 CONST_BITS+PASS1_BITS+3) 3252 & RANGE_MASK]; 3253 outptr[10] = range_limit[(int) RIGHT_SHIFT(tmp23 - tmp13, 3254 CONST_BITS+PASS1_BITS+3) 3255 & RANGE_MASK]; 3256 outptr[4] = range_limit[(int) RIGHT_SHIFT(tmp24 + tmp14, 3257 CONST_BITS+PASS1_BITS+3) 3258 & RANGE_MASK]; 3259 outptr[9] = range_limit[(int) RIGHT_SHIFT(tmp24 - tmp14, 3260 CONST_BITS+PASS1_BITS+3) 3261 & RANGE_MASK]; 3262 outptr[5] = range_limit[(int) RIGHT_SHIFT(tmp25 + tmp15, 3263 CONST_BITS+PASS1_BITS+3) 3264 & RANGE_MASK]; 3265 outptr[8] = range_limit[(int) RIGHT_SHIFT(tmp25 - tmp15, 3266 CONST_BITS+PASS1_BITS+3) 3267 & RANGE_MASK]; 3268 outptr[6] = range_limit[(int) RIGHT_SHIFT(tmp26 + tmp16, 3269 CONST_BITS+PASS1_BITS+3) 3270 & RANGE_MASK]; 3271 outptr[7] = range_limit[(int) RIGHT_SHIFT(tmp26 - tmp16, 3272 CONST_BITS+PASS1_BITS+3) 3273 & RANGE_MASK]; 3274 3275 wsptr += 8; /* advance pointer to next row */ 3276 } 3277 } 3278 3279 3280 /* 3281 * Perform dequantization and inverse DCT on one block of coefficients, 3282 * producing a 12x6 output block. 3283 * 3284 * 6-point IDCT in pass 1 (columns), 12-point in pass 2 (rows). 3285 */ 3286 3287 GLOBAL(void) 3288 jpeg_idct_12x6 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 3289 JCOEFPTR coef_block, 3290 JSAMPARRAY output_buf, JDIMENSION output_col) 3291 { 3292 INT32 tmp10, tmp11, tmp12, tmp13, tmp14, tmp15; 3293 INT32 tmp20, tmp21, tmp22, tmp23, tmp24, tmp25; 3294 INT32 z1, z2, z3, z4; 3295 JCOEFPTR inptr; 3296 ISLOW_MULT_TYPE * quantptr; 3297 int * wsptr; 3298 JSAMPROW outptr; 3299 JSAMPLE *range_limit = IDCT_range_limit(cinfo); 3300 int ctr; 3301 int workspace[8*6]; /* buffers data between passes */ 3302 SHIFT_TEMPS 3303 3304 /* Pass 1: process columns from input, store into work array. 3305 * 6-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/12). 3306 */ 3307 inptr = coef_block; 3308 quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 3309 wsptr = workspace; 3310 for (ctr = 0; ctr < 8; ctr++, inptr++, quantptr++, wsptr++) { 3311 /* Even part */ 3312 3313 tmp10 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); 3314 tmp10 <<= CONST_BITS; 3315 /* Add fudge factor here for final descale. */ 3316 tmp10 += ONE << (CONST_BITS-PASS1_BITS-1); 3317 tmp12 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]); 3318 tmp20 = MULTIPLY(tmp12, FIX(0.707106781)); /* c4 */ 3319 tmp11 = tmp10 + tmp20; 3320 tmp21 = RIGHT_SHIFT(tmp10 - tmp20 - tmp20, CONST_BITS-PASS1_BITS); 3321 tmp20 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]); 3322 tmp10 = MULTIPLY(tmp20, FIX(1.224744871)); /* c2 */ 3323 tmp20 = tmp11 + tmp10; 3324 tmp22 = tmp11 - tmp10; 3325 3326 /* Odd part */ 3327 3328 z1 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); 3329 z2 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]); 3330 z3 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]); 3331 tmp11 = MULTIPLY(z1 + z3, FIX(0.366025404)); /* c5 */ 3332 tmp10 = tmp11 + ((z1 + z2) << CONST_BITS); 3333 tmp12 = tmp11 + ((z3 - z2) << CONST_BITS); 3334 tmp11 = (z1 - z2 - z3) << PASS1_BITS; 3335 3336 /* Final output stage */ 3337 3338 wsptr[8*0] = (int) RIGHT_SHIFT(tmp20 + tmp10, CONST_BITS-PASS1_BITS); 3339 wsptr[8*5] = (int) RIGHT_SHIFT(tmp20 - tmp10, CONST_BITS-PASS1_BITS); 3340 wsptr[8*1] = (int) (tmp21 + tmp11); 3341 wsptr[8*4] = (int) (tmp21 - tmp11); 3342 wsptr[8*2] = (int) RIGHT_SHIFT(tmp22 + tmp12, CONST_BITS-PASS1_BITS); 3343 wsptr[8*3] = (int) RIGHT_SHIFT(tmp22 - tmp12, CONST_BITS-PASS1_BITS); 3344 } 3345 3346 /* Pass 2: process 6 rows from work array, store into output array. 3347 * 12-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/24). 3348 */ 3349 wsptr = workspace; 3350 for (ctr = 0; ctr < 6; ctr++) { 3351 outptr = output_buf[ctr] + output_col; 3352 3353 /* Even part */ 3354 3355 /* Add fudge factor here for final descale. */ 3356 z3 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2)); 3357 z3 <<= CONST_BITS; 3358 3359 z4 = (INT32) wsptr[4]; 3360 z4 = MULTIPLY(z4, FIX(1.224744871)); /* c4 */ 3361 3362 tmp10 = z3 + z4; 3363 tmp11 = z3 - z4; 3364 3365 z1 = (INT32) wsptr[2]; 3366 z4 = MULTIPLY(z1, FIX(1.366025404)); /* c2 */ 3367 z1 <<= CONST_BITS; 3368 z2 = (INT32) wsptr[6]; 3369 z2 <<= CONST_BITS; 3370 3371 tmp12 = z1 - z2; 3372 3373 tmp21 = z3 + tmp12; 3374 tmp24 = z3 - tmp12; 3375 3376 tmp12 = z4 + z2; 3377 3378 tmp20 = tmp10 + tmp12; 3379 tmp25 = tmp10 - tmp12; 3380 3381 tmp12 = z4 - z1 - z2; 3382 3383 tmp22 = tmp11 + tmp12; 3384 tmp23 = tmp11 - tmp12; 3385 3386 /* Odd part */ 3387 3388 z1 = (INT32) wsptr[1]; 3389 z2 = (INT32) wsptr[3]; 3390 z3 = (INT32) wsptr[5]; 3391 z4 = (INT32) wsptr[7]; 3392 3393 tmp11 = MULTIPLY(z2, FIX(1.306562965)); /* c3 */ 3394 tmp14 = MULTIPLY(z2, - FIX_0_541196100); /* -c9 */ 3395 3396 tmp10 = z1 + z3; 3397 tmp15 = MULTIPLY(tmp10 + z4, FIX(0.860918669)); /* c7 */ 3398 tmp12 = tmp15 + MULTIPLY(tmp10, FIX(0.261052384)); /* c5-c7 */ 3399 tmp10 = tmp12 + tmp11 + MULTIPLY(z1, FIX(0.280143716)); /* c1-c5 */ 3400 tmp13 = MULTIPLY(z3 + z4, - FIX(1.045510580)); /* -(c7+c11) */ 3401 tmp12 += tmp13 + tmp14 - MULTIPLY(z3, FIX(1.478575242)); /* c1+c5-c7-c11 */ 3402 tmp13 += tmp15 - tmp11 + MULTIPLY(z4, FIX(1.586706681)); /* c1+c11 */ 3403 tmp15 += tmp14 - MULTIPLY(z1, FIX(0.676326758)) - /* c7-c11 */ 3404 MULTIPLY(z4, FIX(1.982889723)); /* c5+c7 */ 3405 3406 z1 -= z4; 3407 z2 -= z3; 3408 z3 = MULTIPLY(z1 + z2, FIX_0_541196100); /* c9 */ 3409 tmp11 = z3 + MULTIPLY(z1, FIX_0_765366865); /* c3-c9 */ 3410 tmp14 = z3 - MULTIPLY(z2, FIX_1_847759065); /* c3+c9 */ 3411 3412 /* Final output stage */ 3413 3414 outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp20 + tmp10, 3415 CONST_BITS+PASS1_BITS+3) 3416 & RANGE_MASK]; 3417 outptr[11] = range_limit[(int) RIGHT_SHIFT(tmp20 - tmp10, 3418 CONST_BITS+PASS1_BITS+3) 3419 & RANGE_MASK]; 3420 outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp21 + tmp11, 3421 CONST_BITS+PASS1_BITS+3) 3422 & RANGE_MASK]; 3423 outptr[10] = range_limit[(int) RIGHT_SHIFT(tmp21 - tmp11, 3424 CONST_BITS+PASS1_BITS+3) 3425 & RANGE_MASK]; 3426 outptr[2] = range_limit[(int) RIGHT_SHIFT(tmp22 + tmp12, 3427 CONST_BITS+PASS1_BITS+3) 3428 & RANGE_MASK]; 3429 outptr[9] = range_limit[(int) RIGHT_SHIFT(tmp22 - tmp12, 3430 CONST_BITS+PASS1_BITS+3) 3431 & RANGE_MASK]; 3432 outptr[3] = range_limit[(int) RIGHT_SHIFT(tmp23 + tmp13, 3433 CONST_BITS+PASS1_BITS+3) 3434 & RANGE_MASK]; 3435 outptr[8] = range_limit[(int) RIGHT_SHIFT(tmp23 - tmp13, 3436 CONST_BITS+PASS1_BITS+3) 3437 & RANGE_MASK]; 3438 outptr[4] = range_limit[(int) RIGHT_SHIFT(tmp24 + tmp14, 3439 CONST_BITS+PASS1_BITS+3) 3440 & RANGE_MASK]; 3441 outptr[7] = range_limit[(int) RIGHT_SHIFT(tmp24 - tmp14, 3442 CONST_BITS+PASS1_BITS+3) 3443 & RANGE_MASK]; 3444 outptr[5] = range_limit[(int) RIGHT_SHIFT(tmp25 + tmp15, 3445 CONST_BITS+PASS1_BITS+3) 3446 & RANGE_MASK]; 3447 outptr[6] = range_limit[(int) RIGHT_SHIFT(tmp25 - tmp15, 3448 CONST_BITS+PASS1_BITS+3) 3449 & RANGE_MASK]; 3450 3451 wsptr += 8; /* advance pointer to next row */ 3452 } 3453 } 3454 3455 3456 /* 3457 * Perform dequantization and inverse DCT on one block of coefficients, 3458 * producing a 10x5 output block. 3459 * 3460 * 5-point IDCT in pass 1 (columns), 10-point in pass 2 (rows). 3461 */ 3462 3463 GLOBAL(void) 3464 jpeg_idct_10x5 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 3465 JCOEFPTR coef_block, 3466 JSAMPARRAY output_buf, JDIMENSION output_col) 3467 { 3468 INT32 tmp10, tmp11, tmp12, tmp13, tmp14; 3469 INT32 tmp20, tmp21, tmp22, tmp23, tmp24; 3470 INT32 z1, z2, z3, z4; 3471 JCOEFPTR inptr; 3472 ISLOW_MULT_TYPE * quantptr; 3473 int * wsptr; 3474 JSAMPROW outptr; 3475 JSAMPLE *range_limit = IDCT_range_limit(cinfo); 3476 int ctr; 3477 int workspace[8*5]; /* buffers data between passes */ 3478 SHIFT_TEMPS 3479 3480 /* Pass 1: process columns from input, store into work array. 3481 * 5-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/10). 3482 */ 3483 inptr = coef_block; 3484 quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 3485 wsptr = workspace; 3486 for (ctr = 0; ctr < 8; ctr++, inptr++, quantptr++, wsptr++) { 3487 /* Even part */ 3488 3489 tmp12 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); 3490 tmp12 <<= CONST_BITS; 3491 /* Add fudge factor here for final descale. */ 3492 tmp12 += ONE << (CONST_BITS-PASS1_BITS-1); 3493 tmp13 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]); 3494 tmp14 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]); 3495 z1 = MULTIPLY(tmp13 + tmp14, FIX(0.790569415)); /* (c2+c4)/2 */ 3496 z2 = MULTIPLY(tmp13 - tmp14, FIX(0.353553391)); /* (c2-c4)/2 */ 3497 z3 = tmp12 + z2; 3498 tmp10 = z3 + z1; 3499 tmp11 = z3 - z1; 3500 tmp12 -= z2 << 2; 3501 3502 /* Odd part */ 3503 3504 z2 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); 3505 z3 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]); 3506 3507 z1 = MULTIPLY(z2 + z3, FIX(0.831253876)); /* c3 */ 3508 tmp13 = z1 + MULTIPLY(z2, FIX(0.513743148)); /* c1-c3 */ 3509 tmp14 = z1 - MULTIPLY(z3, FIX(2.176250899)); /* c1+c3 */ 3510 3511 /* Final output stage */ 3512 3513 wsptr[8*0] = (int) RIGHT_SHIFT(tmp10 + tmp13, CONST_BITS-PASS1_BITS); 3514 wsptr[8*4] = (int) RIGHT_SHIFT(tmp10 - tmp13, CONST_BITS-PASS1_BITS); 3515 wsptr[8*1] = (int) RIGHT_SHIFT(tmp11 + tmp14, CONST_BITS-PASS1_BITS); 3516 wsptr[8*3] = (int) RIGHT_SHIFT(tmp11 - tmp14, CONST_BITS-PASS1_BITS); 3517 wsptr[8*2] = (int) RIGHT_SHIFT(tmp12, CONST_BITS-PASS1_BITS); 3518 } 3519 3520 /* Pass 2: process 5 rows from work array, store into output array. 3521 * 10-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/20). 3522 */ 3523 wsptr = workspace; 3524 for (ctr = 0; ctr < 5; ctr++) { 3525 outptr = output_buf[ctr] + output_col; 3526 3527 /* Even part */ 3528 3529 /* Add fudge factor here for final descale. */ 3530 z3 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2)); 3531 z3 <<= CONST_BITS; 3532 z4 = (INT32) wsptr[4]; 3533 z1 = MULTIPLY(z4, FIX(1.144122806)); /* c4 */ 3534 z2 = MULTIPLY(z4, FIX(0.437016024)); /* c8 */ 3535 tmp10 = z3 + z1; 3536 tmp11 = z3 - z2; 3537 3538 tmp22 = z3 - ((z1 - z2) << 1); /* c0 = (c4-c8)*2 */ 3539 3540 z2 = (INT32) wsptr[2]; 3541 z3 = (INT32) wsptr[6]; 3542 3543 z1 = MULTIPLY(z2 + z3, FIX(0.831253876)); /* c6 */ 3544 tmp12 = z1 + MULTIPLY(z2, FIX(0.513743148)); /* c2-c6 */ 3545 tmp13 = z1 - MULTIPLY(z3, FIX(2.176250899)); /* c2+c6 */ 3546 3547 tmp20 = tmp10 + tmp12; 3548 tmp24 = tmp10 - tmp12; 3549 tmp21 = tmp11 + tmp13; 3550 tmp23 = tmp11 - tmp13; 3551 3552 /* Odd part */ 3553 3554 z1 = (INT32) wsptr[1]; 3555 z2 = (INT32) wsptr[3]; 3556 z3 = (INT32) wsptr[5]; 3557 z3 <<= CONST_BITS; 3558 z4 = (INT32) wsptr[7]; 3559 3560 tmp11 = z2 + z4; 3561 tmp13 = z2 - z4; 3562 3563 tmp12 = MULTIPLY(tmp13, FIX(0.309016994)); /* (c3-c7)/2 */ 3564 3565 z2 = MULTIPLY(tmp11, FIX(0.951056516)); /* (c3+c7)/2 */ 3566 z4 = z3 + tmp12; 3567 3568 tmp10 = MULTIPLY(z1, FIX(1.396802247)) + z2 + z4; /* c1 */ 3569 tmp14 = MULTIPLY(z1, FIX(0.221231742)) - z2 + z4; /* c9 */ 3570 3571 z2 = MULTIPLY(tmp11, FIX(0.587785252)); /* (c1-c9)/2 */ 3572 z4 = z3 - tmp12 - (tmp13 << (CONST_BITS - 1)); 3573 3574 tmp12 = ((z1 - tmp13) << CONST_BITS) - z3; 3575 3576 tmp11 = MULTIPLY(z1, FIX(1.260073511)) - z2 - z4; /* c3 */ 3577 tmp13 = MULTIPLY(z1, FIX(0.642039522)) - z2 + z4; /* c7 */ 3578 3579 /* Final output stage */ 3580 3581 outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp20 + tmp10, 3582 CONST_BITS+PASS1_BITS+3) 3583 & RANGE_MASK]; 3584 outptr[9] = range_limit[(int) RIGHT_SHIFT(tmp20 - tmp10, 3585 CONST_BITS+PASS1_BITS+3) 3586 & RANGE_MASK]; 3587 outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp21 + tmp11, 3588 CONST_BITS+PASS1_BITS+3) 3589 & RANGE_MASK]; 3590 outptr[8] = range_limit[(int) RIGHT_SHIFT(tmp21 - tmp11, 3591 CONST_BITS+PASS1_BITS+3) 3592 & RANGE_MASK]; 3593 outptr[2] = range_limit[(int) RIGHT_SHIFT(tmp22 + tmp12, 3594 CONST_BITS+PASS1_BITS+3) 3595 & RANGE_MASK]; 3596 outptr[7] = range_limit[(int) RIGHT_SHIFT(tmp22 - tmp12, 3597 CONST_BITS+PASS1_BITS+3) 3598 & RANGE_MASK]; 3599 outptr[3] = range_limit[(int) RIGHT_SHIFT(tmp23 + tmp13, 3600 CONST_BITS+PASS1_BITS+3) 3601 & RANGE_MASK]; 3602 outptr[6] = range_limit[(int) RIGHT_SHIFT(tmp23 - tmp13, 3603 CONST_BITS+PASS1_BITS+3) 3604 & RANGE_MASK]; 3605 outptr[4] = range_limit[(int) RIGHT_SHIFT(tmp24 + tmp14, 3606 CONST_BITS+PASS1_BITS+3) 3607 & RANGE_MASK]; 3608 outptr[5] = range_limit[(int) RIGHT_SHIFT(tmp24 - tmp14, 3609 CONST_BITS+PASS1_BITS+3) 3610 & RANGE_MASK]; 3611 3612 wsptr += 8; /* advance pointer to next row */ 3613 } 3614 } 3615 3616 3617 /* 3618 * Perform dequantization and inverse DCT on one block of coefficients, 3619 * producing a 8x4 output block. 3620 * 3621 * 4-point IDCT in pass 1 (columns), 8-point in pass 2 (rows). 3622 */ 3623 3624 GLOBAL(void) 3625 jpeg_idct_8x4 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 3626 JCOEFPTR coef_block, 3627 JSAMPARRAY output_buf, JDIMENSION output_col) 3628 { 3629 INT32 tmp0, tmp1, tmp2, tmp3; 3630 INT32 tmp10, tmp11, tmp12, tmp13; 3631 INT32 z1, z2, z3; 3632 JCOEFPTR inptr; 3633 ISLOW_MULT_TYPE * quantptr; 3634 int * wsptr; 3635 JSAMPROW outptr; 3636 JSAMPLE *range_limit = IDCT_range_limit(cinfo); 3637 int ctr; 3638 int workspace[8*4]; /* buffers data between passes */ 3639 SHIFT_TEMPS 3640 3641 /* Pass 1: process columns from input, store into work array. 3642 * 4-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/16). 3643 */ 3644 inptr = coef_block; 3645 quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 3646 wsptr = workspace; 3647 for (ctr = 0; ctr < 8; ctr++, inptr++, quantptr++, wsptr++) { 3648 /* Even part */ 3649 3650 tmp0 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); 3651 tmp2 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]); 3652 3653 tmp10 = (tmp0 + tmp2) << PASS1_BITS; 3654 tmp12 = (tmp0 - tmp2) << PASS1_BITS; 3655 3656 /* Odd part */ 3657 /* Same rotation as in the even part of the 8x8 LL&M IDCT */ 3658 3659 z2 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); 3660 z3 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]); 3661 3662 z1 = MULTIPLY(z2 + z3, FIX_0_541196100); /* c6 */ 3663 /* Add fudge factor here for final descale. */ 3664 z1 += ONE << (CONST_BITS-PASS1_BITS-1); 3665 tmp0 = RIGHT_SHIFT(z1 + MULTIPLY(z2, FIX_0_765366865), /* c2-c6 */ 3666 CONST_BITS-PASS1_BITS); 3667 tmp2 = RIGHT_SHIFT(z1 - MULTIPLY(z3, FIX_1_847759065), /* c2+c6 */ 3668 CONST_BITS-PASS1_BITS); 3669 3670 /* Final output stage */ 3671 3672 wsptr[8*0] = (int) (tmp10 + tmp0); 3673 wsptr[8*3] = (int) (tmp10 - tmp0); 3674 wsptr[8*1] = (int) (tmp12 + tmp2); 3675 wsptr[8*2] = (int) (tmp12 - tmp2); 3676 } 3677 3678 /* Pass 2: process rows from work array, store into output array. */ 3679 /* Note that we must descale the results by a factor of 8 == 2**3, */ 3680 /* and also undo the PASS1_BITS scaling. */ 3681 3682 wsptr = workspace; 3683 for (ctr = 0; ctr < 4; ctr++) { 3684 outptr = output_buf[ctr] + output_col; 3685 3686 /* Even part: reverse the even part of the forward DCT. */ 3687 /* The rotator is sqrt(2)*c(-6). */ 3688 3689 z2 = (INT32) wsptr[2]; 3690 z3 = (INT32) wsptr[6]; 3691 3692 z1 = MULTIPLY(z2 + z3, FIX_0_541196100); 3693 tmp2 = z1 + MULTIPLY(z2, FIX_0_765366865); 3694 tmp3 = z1 - MULTIPLY(z3, FIX_1_847759065); 3695 3696 /* Add fudge factor here for final descale. */ 3697 z2 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2)); 3698 z3 = (INT32) wsptr[4]; 3699 3700 tmp0 = (z2 + z3) << CONST_BITS; 3701 tmp1 = (z2 - z3) << CONST_BITS; 3702 3703 tmp10 = tmp0 + tmp2; 3704 tmp13 = tmp0 - tmp2; 3705 tmp11 = tmp1 + tmp3; 3706 tmp12 = tmp1 - tmp3; 3707 3708 /* Odd part per figure 8; the matrix is unitary and hence its 3709 * transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively. 3710 */ 3711 3712 tmp0 = (INT32) wsptr[7]; 3713 tmp1 = (INT32) wsptr[5]; 3714 tmp2 = (INT32) wsptr[3]; 3715 tmp3 = (INT32) wsptr[1]; 3716 3717 z2 = tmp0 + tmp2; 3718 z3 = tmp1 + tmp3; 3719 3720 z1 = MULTIPLY(z2 + z3, FIX_1_175875602); /* sqrt(2) * c3 */ 3721 z2 = MULTIPLY(z2, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */ 3722 z3 = MULTIPLY(z3, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */ 3723 z2 += z1; 3724 z3 += z1; 3725 3726 z1 = MULTIPLY(tmp0 + tmp3, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */ 3727 tmp0 = MULTIPLY(tmp0, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */ 3728 tmp3 = MULTIPLY(tmp3, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */ 3729 tmp0 += z1 + z2; 3730 tmp3 += z1 + z3; 3731 3732 z1 = MULTIPLY(tmp1 + tmp2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */ 3733 tmp1 = MULTIPLY(tmp1, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */ 3734 tmp2 = MULTIPLY(tmp2, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */ 3735 tmp1 += z1 + z3; 3736 tmp2 += z1 + z2; 3737 3738 /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */ 3739 3740 outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp10 + tmp3, 3741 CONST_BITS+PASS1_BITS+3) 3742 & RANGE_MASK]; 3743 outptr[7] = range_limit[(int) RIGHT_SHIFT(tmp10 - tmp3, 3744 CONST_BITS+PASS1_BITS+3) 3745 & RANGE_MASK]; 3746 outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp11 + tmp2, 3747 CONST_BITS+PASS1_BITS+3) 3748 & RANGE_MASK]; 3749 outptr[6] = range_limit[(int) RIGHT_SHIFT(tmp11 - tmp2, 3750 CONST_BITS+PASS1_BITS+3) 3751 & RANGE_MASK]; 3752 outptr[2] = range_limit[(int) RIGHT_SHIFT(tmp12 + tmp1, 3753 CONST_BITS+PASS1_BITS+3) 3754 & RANGE_MASK]; 3755 outptr[5] = range_limit[(int) RIGHT_SHIFT(tmp12 - tmp1, 3756 CONST_BITS+PASS1_BITS+3) 3757 & RANGE_MASK]; 3758 outptr[3] = range_limit[(int) RIGHT_SHIFT(tmp13 + tmp0, 3759 CONST_BITS+PASS1_BITS+3) 3760 & RANGE_MASK]; 3761 outptr[4] = range_limit[(int) RIGHT_SHIFT(tmp13 - tmp0, 3762 CONST_BITS+PASS1_BITS+3) 3763 & RANGE_MASK]; 3764 3765 wsptr += DCTSIZE; /* advance pointer to next row */ 3766 } 3767 } 3768 3769 3770 /* 3771 * Perform dequantization and inverse DCT on one block of coefficients, 3772 * producing a reduced-size 6x3 output block. 3773 * 3774 * 3-point IDCT in pass 1 (columns), 6-point in pass 2 (rows). 3775 */ 3776 3777 GLOBAL(void) 3778 jpeg_idct_6x3 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 3779 JCOEFPTR coef_block, 3780 JSAMPARRAY output_buf, JDIMENSION output_col) 3781 { 3782 INT32 tmp0, tmp1, tmp2, tmp10, tmp11, tmp12; 3783 INT32 z1, z2, z3; 3784 JCOEFPTR inptr; 3785 ISLOW_MULT_TYPE * quantptr; 3786 int * wsptr; 3787 JSAMPROW outptr; 3788 JSAMPLE *range_limit = IDCT_range_limit(cinfo); 3789 int ctr; 3790 int workspace[6*3]; /* buffers data between passes */ 3791 SHIFT_TEMPS 3792 3793 /* Pass 1: process columns from input, store into work array. 3794 * 3-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/6). 3795 */ 3796 inptr = coef_block; 3797 quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 3798 wsptr = workspace; 3799 for (ctr = 0; ctr < 6; ctr++, inptr++, quantptr++, wsptr++) { 3800 /* Even part */ 3801 3802 tmp0 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); 3803 tmp0 <<= CONST_BITS; 3804 /* Add fudge factor here for final descale. */ 3805 tmp0 += ONE << (CONST_BITS-PASS1_BITS-1); 3806 tmp2 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]); 3807 tmp12 = MULTIPLY(tmp2, FIX(0.707106781)); /* c2 */ 3808 tmp10 = tmp0 + tmp12; 3809 tmp2 = tmp0 - tmp12 - tmp12; 3810 3811 /* Odd part */ 3812 3813 tmp12 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); 3814 tmp0 = MULTIPLY(tmp12, FIX(1.224744871)); /* c1 */ 3815 3816 /* Final output stage */ 3817 3818 wsptr[6*0] = (int) RIGHT_SHIFT(tmp10 + tmp0, CONST_BITS-PASS1_BITS); 3819 wsptr[6*2] = (int) RIGHT_SHIFT(tmp10 - tmp0, CONST_BITS-PASS1_BITS); 3820 wsptr[6*1] = (int) RIGHT_SHIFT(tmp2, CONST_BITS-PASS1_BITS); 3821 } 3822 3823 /* Pass 2: process 3 rows from work array, store into output array. 3824 * 6-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/12). 3825 */ 3826 wsptr = workspace; 3827 for (ctr = 0; ctr < 3; ctr++) { 3828 outptr = output_buf[ctr] + output_col; 3829 3830 /* Even part */ 3831 3832 /* Add fudge factor here for final descale. */ 3833 tmp0 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2)); 3834 tmp0 <<= CONST_BITS; 3835 tmp2 = (INT32) wsptr[4]; 3836 tmp10 = MULTIPLY(tmp2, FIX(0.707106781)); /* c4 */ 3837 tmp1 = tmp0 + tmp10; 3838 tmp11 = tmp0 - tmp10 - tmp10; 3839 tmp10 = (INT32) wsptr[2]; 3840 tmp0 = MULTIPLY(tmp10, FIX(1.224744871)); /* c2 */ 3841 tmp10 = tmp1 + tmp0; 3842 tmp12 = tmp1 - tmp0; 3843 3844 /* Odd part */ 3845 3846 z1 = (INT32) wsptr[1]; 3847 z2 = (INT32) wsptr[3]; 3848 z3 = (INT32) wsptr[5]; 3849 tmp1 = MULTIPLY(z1 + z3, FIX(0.366025404)); /* c5 */ 3850 tmp0 = tmp1 + ((z1 + z2) << CONST_BITS); 3851 tmp2 = tmp1 + ((z3 - z2) << CONST_BITS); 3852 tmp1 = (z1 - z2 - z3) << CONST_BITS; 3853 3854 /* Final output stage */ 3855 3856 outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp10 + tmp0, 3857 CONST_BITS+PASS1_BITS+3) 3858 & RANGE_MASK]; 3859 outptr[5] = range_limit[(int) RIGHT_SHIFT(tmp10 - tmp0, 3860 CONST_BITS+PASS1_BITS+3) 3861 & RANGE_MASK]; 3862 outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp11 + tmp1, 3863 CONST_BITS+PASS1_BITS+3) 3864 & RANGE_MASK]; 3865 outptr[4] = range_limit[(int) RIGHT_SHIFT(tmp11 - tmp1, 3866 CONST_BITS+PASS1_BITS+3) 3867 & RANGE_MASK]; 3868 outptr[2] = range_limit[(int) RIGHT_SHIFT(tmp12 + tmp2, 3869 CONST_BITS+PASS1_BITS+3) 3870 & RANGE_MASK]; 3871 outptr[3] = range_limit[(int) RIGHT_SHIFT(tmp12 - tmp2, 3872 CONST_BITS+PASS1_BITS+3) 3873 & RANGE_MASK]; 3874 3875 wsptr += 6; /* advance pointer to next row */ 3876 } 3877 } 3878 3879 3880 /* 3881 * Perform dequantization and inverse DCT on one block of coefficients, 3882 * producing a 4x2 output block. 3883 * 3884 * 2-point IDCT in pass 1 (columns), 4-point in pass 2 (rows). 3885 */ 3886 3887 GLOBAL(void) 3888 jpeg_idct_4x2 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 3889 JCOEFPTR coef_block, 3890 JSAMPARRAY output_buf, JDIMENSION output_col) 3891 { 3892 INT32 tmp0, tmp2, tmp10, tmp12; 3893 INT32 z1, z2, z3; 3894 JCOEFPTR inptr; 3895 ISLOW_MULT_TYPE * quantptr; 3896 INT32 * wsptr; 3897 JSAMPROW outptr; 3898 JSAMPLE *range_limit = IDCT_range_limit(cinfo); 3899 int ctr; 3900 INT32 workspace[4*2]; /* buffers data between passes */ 3901 SHIFT_TEMPS 3902 3903 /* Pass 1: process columns from input, store into work array. */ 3904 3905 inptr = coef_block; 3906 quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 3907 wsptr = workspace; 3908 for (ctr = 0; ctr < 4; ctr++, inptr++, quantptr++, wsptr++) { 3909 /* Even part */ 3910 3911 tmp10 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); 3912 3913 /* Odd part */ 3914 3915 tmp0 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); 3916 3917 /* Final output stage */ 3918 3919 wsptr[4*0] = tmp10 + tmp0; 3920 wsptr[4*1] = tmp10 - tmp0; 3921 } 3922 3923 /* Pass 2: process 2 rows from work array, store into output array. 3924 * 4-point IDCT kernel, 3925 * cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point IDCT]. 3926 */ 3927 wsptr = workspace; 3928 for (ctr = 0; ctr < 2; ctr++) { 3929 outptr = output_buf[ctr] + output_col; 3930 3931 /* Even part */ 3932 3933 /* Add fudge factor here for final descale. */ 3934 tmp0 = wsptr[0] + (ONE << 2); 3935 tmp2 = wsptr[2]; 3936 3937 tmp10 = (tmp0 + tmp2) << CONST_BITS; 3938 tmp12 = (tmp0 - tmp2) << CONST_BITS; 3939 3940 /* Odd part */ 3941 /* Same rotation as in the even part of the 8x8 LL&M IDCT */ 3942 3943 z2 = wsptr[1]; 3944 z3 = wsptr[3]; 3945 3946 z1 = MULTIPLY(z2 + z3, FIX_0_541196100); /* c6 */ 3947 tmp0 = z1 + MULTIPLY(z2, FIX_0_765366865); /* c2-c6 */ 3948 tmp2 = z1 - MULTIPLY(z3, FIX_1_847759065); /* c2+c6 */ 3949 3950 /* Final output stage */ 3951 3952 outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp10 + tmp0, 3953 CONST_BITS+3) 3954 & RANGE_MASK]; 3955 outptr[3] = range_limit[(int) RIGHT_SHIFT(tmp10 - tmp0, 3956 CONST_BITS+3) 3957 & RANGE_MASK]; 3958 outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp12 + tmp2, 3959 CONST_BITS+3) 3960 & RANGE_MASK]; 3961 outptr[2] = range_limit[(int) RIGHT_SHIFT(tmp12 - tmp2, 3962 CONST_BITS+3) 3963 & RANGE_MASK]; 3964 3965 wsptr += 4; /* advance pointer to next row */ 3966 } 3967 } 3968 3969 3970 /* 3971 * Perform dequantization and inverse DCT on one block of coefficients, 3972 * producing a 2x1 output block. 3973 * 3974 * 1-point IDCT in pass 1 (columns), 2-point in pass 2 (rows). 3975 */ 3976 3977 GLOBAL(void) 3978 jpeg_idct_2x1 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 3979 JCOEFPTR coef_block, 3980 JSAMPARRAY output_buf, JDIMENSION output_col) 3981 { 3982 INT32 tmp0, tmp10; 3983 ISLOW_MULT_TYPE * quantptr; 3984 JSAMPROW outptr; 3985 JSAMPLE *range_limit = IDCT_range_limit(cinfo); 3986 SHIFT_TEMPS 3987 3988 /* Pass 1: empty. */ 3989 3990 /* Pass 2: process 1 row from input, store into output array. */ 3991 3992 quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 3993 outptr = output_buf[0] + output_col; 3994 3995 /* Even part */ 3996 3997 tmp10 = DEQUANTIZE(coef_block[0], quantptr[0]); 3998 /* Add fudge factor here for final descale. */ 3999 tmp10 += ONE << 2; 4000 4001 /* Odd part */ 4002 4003 tmp0 = DEQUANTIZE(coef_block[1], quantptr[1]); 4004 4005 /* Final output stage */ 4006 4007 outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp10 + tmp0, 3) & RANGE_MASK]; 4008 outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp10 - tmp0, 3) & RANGE_MASK]; 4009 } 4010 4011 4012 /* 4013 * Perform dequantization and inverse DCT on one block of coefficients, 4014 * producing a 8x16 output block. 4015 * 4016 * 16-point IDCT in pass 1 (columns), 8-point in pass 2 (rows). 4017 */ 4018 4019 GLOBAL(void) 4020 jpeg_idct_8x16 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 4021 JCOEFPTR coef_block, 4022 JSAMPARRAY output_buf, JDIMENSION output_col) 4023 { 4024 INT32 tmp0, tmp1, tmp2, tmp3, tmp10, tmp11, tmp12, tmp13; 4025 INT32 tmp20, tmp21, tmp22, tmp23, tmp24, tmp25, tmp26, tmp27; 4026 INT32 z1, z2, z3, z4; 4027 JCOEFPTR inptr; 4028 ISLOW_MULT_TYPE * quantptr; 4029 int * wsptr; 4030 JSAMPROW outptr; 4031 JSAMPLE *range_limit = IDCT_range_limit(cinfo); 4032 int ctr; 4033 int workspace[8*16]; /* buffers data between passes */ 4034 SHIFT_TEMPS 4035 4036 /* Pass 1: process columns from input, store into work array. 4037 * 16-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/32). 4038 */ 4039 inptr = coef_block; 4040 quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 4041 wsptr = workspace; 4042 for (ctr = 0; ctr < 8; ctr++, inptr++, quantptr++, wsptr++) { 4043 /* Even part */ 4044 4045 tmp0 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); 4046 tmp0 <<= CONST_BITS; 4047 /* Add fudge factor here for final descale. */ 4048 tmp0 += ONE << (CONST_BITS-PASS1_BITS-1); 4049 4050 z1 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]); 4051 tmp1 = MULTIPLY(z1, FIX(1.306562965)); /* c4[16] = c2[8] */ 4052 tmp2 = MULTIPLY(z1, FIX_0_541196100); /* c12[16] = c6[8] */ 4053 4054 tmp10 = tmp0 + tmp1; 4055 tmp11 = tmp0 - tmp1; 4056 tmp12 = tmp0 + tmp2; 4057 tmp13 = tmp0 - tmp2; 4058 4059 z1 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]); 4060 z2 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]); 4061 z3 = z1 - z2; 4062 z4 = MULTIPLY(z3, FIX(0.275899379)); /* c14[16] = c7[8] */ 4063 z3 = MULTIPLY(z3, FIX(1.387039845)); /* c2[16] = c1[8] */ 4064 4065 tmp0 = z3 + MULTIPLY(z2, FIX_2_562915447); /* (c6+c2)[16] = (c3+c1)[8] */ 4066 tmp1 = z4 + MULTIPLY(z1, FIX_0_899976223); /* (c6-c14)[16] = (c3-c7)[8] */ 4067 tmp2 = z3 - MULTIPLY(z1, FIX(0.601344887)); /* (c2-c10)[16] = (c1-c5)[8] */ 4068 tmp3 = z4 - MULTIPLY(z2, FIX(0.509795579)); /* (c10-c14)[16] = (c5-c7)[8] */ 4069 4070 tmp20 = tmp10 + tmp0; 4071 tmp27 = tmp10 - tmp0; 4072 tmp21 = tmp12 + tmp1; 4073 tmp26 = tmp12 - tmp1; 4074 tmp22 = tmp13 + tmp2; 4075 tmp25 = tmp13 - tmp2; 4076 tmp23 = tmp11 + tmp3; 4077 tmp24 = tmp11 - tmp3; 4078 4079 /* Odd part */ 4080 4081 z1 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); 4082 z2 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]); 4083 z3 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]); 4084 z4 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]); 4085 4086 tmp11 = z1 + z3; 4087 4088 tmp1 = MULTIPLY(z1 + z2, FIX(1.353318001)); /* c3 */ 4089 tmp2 = MULTIPLY(tmp11, FIX(1.247225013)); /* c5 */ 4090 tmp3 = MULTIPLY(z1 + z4, FIX(1.093201867)); /* c7 */ 4091 tmp10 = MULTIPLY(z1 - z4, FIX(0.897167586)); /* c9 */ 4092 tmp11 = MULTIPLY(tmp11, FIX(0.666655658)); /* c11 */ 4093 tmp12 = MULTIPLY(z1 - z2, FIX(0.410524528)); /* c13 */ 4094 tmp0 = tmp1 + tmp2 + tmp3 - 4095 MULTIPLY(z1, FIX(2.286341144)); /* c7+c5+c3-c1 */ 4096 tmp13 = tmp10 + tmp11 + tmp12 - 4097 MULTIPLY(z1, FIX(1.835730603)); /* c9+c11+c13-c15 */ 4098 z1 = MULTIPLY(z2 + z3, FIX(0.138617169)); /* c15 */ 4099 tmp1 += z1 + MULTIPLY(z2, FIX(0.071888074)); /* c9+c11-c3-c15 */ 4100 tmp2 += z1 - MULTIPLY(z3, FIX(1.125726048)); /* c5+c7+c15-c3 */ 4101 z1 = MULTIPLY(z3 - z2, FIX(1.407403738)); /* c1 */ 4102 tmp11 += z1 - MULTIPLY(z3, FIX(0.766367282)); /* c1+c11-c9-c13 */ 4103 tmp12 += z1 + MULTIPLY(z2, FIX(1.971951411)); /* c1+c5+c13-c7 */ 4104 z2 += z4; 4105 z1 = MULTIPLY(z2, - FIX(0.666655658)); /* -c11 */ 4106 tmp1 += z1; 4107 tmp3 += z1 + MULTIPLY(z4, FIX(1.065388962)); /* c3+c11+c15-c7 */ 4108 z2 = MULTIPLY(z2, - FIX(1.247225013)); /* -c5 */ 4109 tmp10 += z2 + MULTIPLY(z4, FIX(3.141271809)); /* c1+c5+c9-c13 */ 4110 tmp12 += z2; 4111 z2 = MULTIPLY(z3 + z4, - FIX(1.353318001)); /* -c3 */ 4112 tmp2 += z2; 4113 tmp3 += z2; 4114 z2 = MULTIPLY(z4 - z3, FIX(0.410524528)); /* c13 */ 4115 tmp10 += z2; 4116 tmp11 += z2; 4117 4118 /* Final output stage */ 4119 4120 wsptr[8*0] = (int) RIGHT_SHIFT(tmp20 + tmp0, CONST_BITS-PASS1_BITS); 4121 wsptr[8*15] = (int) RIGHT_SHIFT(tmp20 - tmp0, CONST_BITS-PASS1_BITS); 4122 wsptr[8*1] = (int) RIGHT_SHIFT(tmp21 + tmp1, CONST_BITS-PASS1_BITS); 4123 wsptr[8*14] = (int) RIGHT_SHIFT(tmp21 - tmp1, CONST_BITS-PASS1_BITS); 4124 wsptr[8*2] = (int) RIGHT_SHIFT(tmp22 + tmp2, CONST_BITS-PASS1_BITS); 4125 wsptr[8*13] = (int) RIGHT_SHIFT(tmp22 - tmp2, CONST_BITS-PASS1_BITS); 4126 wsptr[8*3] = (int) RIGHT_SHIFT(tmp23 + tmp3, CONST_BITS-PASS1_BITS); 4127 wsptr[8*12] = (int) RIGHT_SHIFT(tmp23 - tmp3, CONST_BITS-PASS1_BITS); 4128 wsptr[8*4] = (int) RIGHT_SHIFT(tmp24 + tmp10, CONST_BITS-PASS1_BITS); 4129 wsptr[8*11] = (int) RIGHT_SHIFT(tmp24 - tmp10, CONST_BITS-PASS1_BITS); 4130 wsptr[8*5] = (int) RIGHT_SHIFT(tmp25 + tmp11, CONST_BITS-PASS1_BITS); 4131 wsptr[8*10] = (int) RIGHT_SHIFT(tmp25 - tmp11, CONST_BITS-PASS1_BITS); 4132 wsptr[8*6] = (int) RIGHT_SHIFT(tmp26 + tmp12, CONST_BITS-PASS1_BITS); 4133 wsptr[8*9] = (int) RIGHT_SHIFT(tmp26 - tmp12, CONST_BITS-PASS1_BITS); 4134 wsptr[8*7] = (int) RIGHT_SHIFT(tmp27 + tmp13, CONST_BITS-PASS1_BITS); 4135 wsptr[8*8] = (int) RIGHT_SHIFT(tmp27 - tmp13, CONST_BITS-PASS1_BITS); 4136 } 4137 4138 /* Pass 2: process rows from work array, store into output array. */ 4139 /* Note that we must descale the results by a factor of 8 == 2**3, */ 4140 /* and also undo the PASS1_BITS scaling. */ 4141 4142 wsptr = workspace; 4143 for (ctr = 0; ctr < 16; ctr++) { 4144 outptr = output_buf[ctr] + output_col; 4145 4146 /* Even part: reverse the even part of the forward DCT. */ 4147 /* The rotator is sqrt(2)*c(-6). */ 4148 4149 z2 = (INT32) wsptr[2]; 4150 z3 = (INT32) wsptr[6]; 4151 4152 z1 = MULTIPLY(z2 + z3, FIX_0_541196100); 4153 tmp2 = z1 + MULTIPLY(z2, FIX_0_765366865); 4154 tmp3 = z1 - MULTIPLY(z3, FIX_1_847759065); 4155 4156 /* Add fudge factor here for final descale. */ 4157 z2 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2)); 4158 z3 = (INT32) wsptr[4]; 4159 4160 tmp0 = (z2 + z3) << CONST_BITS; 4161 tmp1 = (z2 - z3) << CONST_BITS; 4162 4163 tmp10 = tmp0 + tmp2; 4164 tmp13 = tmp0 - tmp2; 4165 tmp11 = tmp1 + tmp3; 4166 tmp12 = tmp1 - tmp3; 4167 4168 /* Odd part per figure 8; the matrix is unitary and hence its 4169 * transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively. 4170 */ 4171 4172 tmp0 = (INT32) wsptr[7]; 4173 tmp1 = (INT32) wsptr[5]; 4174 tmp2 = (INT32) wsptr[3]; 4175 tmp3 = (INT32) wsptr[1]; 4176 4177 z2 = tmp0 + tmp2; 4178 z3 = tmp1 + tmp3; 4179 4180 z1 = MULTIPLY(z2 + z3, FIX_1_175875602); /* sqrt(2) * c3 */ 4181 z2 = MULTIPLY(z2, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */ 4182 z3 = MULTIPLY(z3, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */ 4183 z2 += z1; 4184 z3 += z1; 4185 4186 z1 = MULTIPLY(tmp0 + tmp3, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */ 4187 tmp0 = MULTIPLY(tmp0, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */ 4188 tmp3 = MULTIPLY(tmp3, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */ 4189 tmp0 += z1 + z2; 4190 tmp3 += z1 + z3; 4191 4192 z1 = MULTIPLY(tmp1 + tmp2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */ 4193 tmp1 = MULTIPLY(tmp1, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */ 4194 tmp2 = MULTIPLY(tmp2, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */ 4195 tmp1 += z1 + z3; 4196 tmp2 += z1 + z2; 4197 4198 /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */ 4199 4200 outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp10 + tmp3, 4201 CONST_BITS+PASS1_BITS+3) 4202 & RANGE_MASK]; 4203 outptr[7] = range_limit[(int) RIGHT_SHIFT(tmp10 - tmp3, 4204 CONST_BITS+PASS1_BITS+3) 4205 & RANGE_MASK]; 4206 outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp11 + tmp2, 4207 CONST_BITS+PASS1_BITS+3) 4208 & RANGE_MASK]; 4209 outptr[6] = range_limit[(int) RIGHT_SHIFT(tmp11 - tmp2, 4210 CONST_BITS+PASS1_BITS+3) 4211 & RANGE_MASK]; 4212 outptr[2] = range_limit[(int) RIGHT_SHIFT(tmp12 + tmp1, 4213 CONST_BITS+PASS1_BITS+3) 4214 & RANGE_MASK]; 4215 outptr[5] = range_limit[(int) RIGHT_SHIFT(tmp12 - tmp1, 4216 CONST_BITS+PASS1_BITS+3) 4217 & RANGE_MASK]; 4218 outptr[3] = range_limit[(int) RIGHT_SHIFT(tmp13 + tmp0, 4219 CONST_BITS+PASS1_BITS+3) 4220 & RANGE_MASK]; 4221 outptr[4] = range_limit[(int) RIGHT_SHIFT(tmp13 - tmp0, 4222 CONST_BITS+PASS1_BITS+3) 4223 & RANGE_MASK]; 4224 4225 wsptr += DCTSIZE; /* advance pointer to next row */ 4226 } 4227 } 4228 4229 4230 /* 4231 * Perform dequantization and inverse DCT on one block of coefficients, 4232 * producing a 7x14 output block. 4233 * 4234 * 14-point IDCT in pass 1 (columns), 7-point in pass 2 (rows). 4235 */ 4236 4237 GLOBAL(void) 4238 jpeg_idct_7x14 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 4239 JCOEFPTR coef_block, 4240 JSAMPARRAY output_buf, JDIMENSION output_col) 4241 { 4242 INT32 tmp10, tmp11, tmp12, tmp13, tmp14, tmp15, tmp16; 4243 INT32 tmp20, tmp21, tmp22, tmp23, tmp24, tmp25, tmp26; 4244 INT32 z1, z2, z3, z4; 4245 JCOEFPTR inptr; 4246 ISLOW_MULT_TYPE * quantptr; 4247 int * wsptr; 4248 JSAMPROW outptr; 4249 JSAMPLE *range_limit = IDCT_range_limit(cinfo); 4250 int ctr; 4251 int workspace[7*14]; /* buffers data between passes */ 4252 SHIFT_TEMPS 4253 4254 /* Pass 1: process columns from input, store into work array. 4255 * 14-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/28). 4256 */ 4257 inptr = coef_block; 4258 quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 4259 wsptr = workspace; 4260 for (ctr = 0; ctr < 7; ctr++, inptr++, quantptr++, wsptr++) { 4261 /* Even part */ 4262 4263 z1 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); 4264 z1 <<= CONST_BITS; 4265 /* Add fudge factor here for final descale. */ 4266 z1 += ONE << (CONST_BITS-PASS1_BITS-1); 4267 z4 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]); 4268 z2 = MULTIPLY(z4, FIX(1.274162392)); /* c4 */ 4269 z3 = MULTIPLY(z4, FIX(0.314692123)); /* c12 */ 4270 z4 = MULTIPLY(z4, FIX(0.881747734)); /* c8 */ 4271 4272 tmp10 = z1 + z2; 4273 tmp11 = z1 + z3; 4274 tmp12 = z1 - z4; 4275 4276 tmp23 = RIGHT_SHIFT(z1 - ((z2 + z3 - z4) << 1), /* c0 = (c4+c12-c8)*2 */ 4277 CONST_BITS-PASS1_BITS); 4278 4279 z1 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]); 4280 z2 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]); 4281 4282 z3 = MULTIPLY(z1 + z2, FIX(1.105676686)); /* c6 */ 4283 4284 tmp13 = z3 + MULTIPLY(z1, FIX(0.273079590)); /* c2-c6 */ 4285 tmp14 = z3 - MULTIPLY(z2, FIX(1.719280954)); /* c6+c10 */ 4286 tmp15 = MULTIPLY(z1, FIX(0.613604268)) - /* c10 */ 4287 MULTIPLY(z2, FIX(1.378756276)); /* c2 */ 4288 4289 tmp20 = tmp10 + tmp13; 4290 tmp26 = tmp10 - tmp13; 4291 tmp21 = tmp11 + tmp14; 4292 tmp25 = tmp11 - tmp14; 4293 tmp22 = tmp12 + tmp15; 4294 tmp24 = tmp12 - tmp15; 4295 4296 /* Odd part */ 4297 4298 z1 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); 4299 z2 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]); 4300 z3 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]); 4301 z4 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]); 4302 tmp13 = z4 << CONST_BITS; 4303 4304 tmp14 = z1 + z3; 4305 tmp11 = MULTIPLY(z1 + z2, FIX(1.334852607)); /* c3 */ 4306 tmp12 = MULTIPLY(tmp14, FIX(1.197448846)); /* c5 */ 4307 tmp10 = tmp11 + tmp12 + tmp13 - MULTIPLY(z1, FIX(1.126980169)); /* c3+c5-c1 */ 4308 tmp14 = MULTIPLY(tmp14, FIX(0.752406978)); /* c9 */ 4309 tmp16 = tmp14 - MULTIPLY(z1, FIX(1.061150426)); /* c9+c11-c13 */ 4310 z1 -= z2; 4311 tmp15 = MULTIPLY(z1, FIX(0.467085129)) - tmp13; /* c11 */ 4312 tmp16 += tmp15; 4313 z1 += z4; 4314 z4 = MULTIPLY(z2 + z3, - FIX(0.158341681)) - tmp13; /* -c13 */ 4315 tmp11 += z4 - MULTIPLY(z2, FIX(0.424103948)); /* c3-c9-c13 */ 4316 tmp12 += z4 - MULTIPLY(z3, FIX(2.373959773)); /* c3+c5-c13 */ 4317 z4 = MULTIPLY(z3 - z2, FIX(1.405321284)); /* c1 */ 4318 tmp14 += z4 + tmp13 - MULTIPLY(z3, FIX(1.6906431334)); /* c1+c9-c11 */ 4319 tmp15 += z4 + MULTIPLY(z2, FIX(0.674957567)); /* c1+c11-c5 */ 4320 4321 tmp13 = (z1 - z3) << PASS1_BITS; 4322 4323 /* Final output stage */ 4324 4325 wsptr[7*0] = (int) RIGHT_SHIFT(tmp20 + tmp10, CONST_BITS-PASS1_BITS); 4326 wsptr[7*13] = (int) RIGHT_SHIFT(tmp20 - tmp10, CONST_BITS-PASS1_BITS); 4327 wsptr[7*1] = (int) RIGHT_SHIFT(tmp21 + tmp11, CONST_BITS-PASS1_BITS); 4328 wsptr[7*12] = (int) RIGHT_SHIFT(tmp21 - tmp11, CONST_BITS-PASS1_BITS); 4329 wsptr[7*2] = (int) RIGHT_SHIFT(tmp22 + tmp12, CONST_BITS-PASS1_BITS); 4330 wsptr[7*11] = (int) RIGHT_SHIFT(tmp22 - tmp12, CONST_BITS-PASS1_BITS); 4331 wsptr[7*3] = (int) (tmp23 + tmp13); 4332 wsptr[7*10] = (int) (tmp23 - tmp13); 4333 wsptr[7*4] = (int) RIGHT_SHIFT(tmp24 + tmp14, CONST_BITS-PASS1_BITS); 4334 wsptr[7*9] = (int) RIGHT_SHIFT(tmp24 - tmp14, CONST_BITS-PASS1_BITS); 4335 wsptr[7*5] = (int) RIGHT_SHIFT(tmp25 + tmp15, CONST_BITS-PASS1_BITS); 4336 wsptr[7*8] = (int) RIGHT_SHIFT(tmp25 - tmp15, CONST_BITS-PASS1_BITS); 4337 wsptr[7*6] = (int) RIGHT_SHIFT(tmp26 + tmp16, CONST_BITS-PASS1_BITS); 4338 wsptr[7*7] = (int) RIGHT_SHIFT(tmp26 - tmp16, CONST_BITS-PASS1_BITS); 4339 } 4340 4341 /* Pass 2: process 14 rows from work array, store into output array. 4342 * 7-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/14). 4343 */ 4344 wsptr = workspace; 4345 for (ctr = 0; ctr < 14; ctr++) { 4346 outptr = output_buf[ctr] + output_col; 4347 4348 /* Even part */ 4349 4350 /* Add fudge factor here for final descale. */ 4351 tmp23 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2)); 4352 tmp23 <<= CONST_BITS; 4353 4354 z1 = (INT32) wsptr[2]; 4355 z2 = (INT32) wsptr[4]; 4356 z3 = (INT32) wsptr[6]; 4357 4358 tmp20 = MULTIPLY(z2 - z3, FIX(0.881747734)); /* c4 */ 4359 tmp22 = MULTIPLY(z1 - z2, FIX(0.314692123)); /* c6 */ 4360 tmp21 = tmp20 + tmp22 + tmp23 - MULTIPLY(z2, FIX(1.841218003)); /* c2+c4-c6 */ 4361 tmp10 = z1 + z3; 4362 z2 -= tmp10; 4363 tmp10 = MULTIPLY(tmp10, FIX(1.274162392)) + tmp23; /* c2 */ 4364 tmp20 += tmp10 - MULTIPLY(z3, FIX(0.077722536)); /* c2-c4-c6 */ 4365 tmp22 += tmp10 - MULTIPLY(z1, FIX(2.470602249)); /* c2+c4+c6 */ 4366 tmp23 += MULTIPLY(z2, FIX(1.414213562)); /* c0 */ 4367 4368 /* Odd part */ 4369 4370 z1 = (INT32) wsptr[1]; 4371 z2 = (INT32) wsptr[3]; 4372 z3 = (INT32) wsptr[5]; 4373 4374 tmp11 = MULTIPLY(z1 + z2, FIX(0.935414347)); /* (c3+c1-c5)/2 */ 4375 tmp12 = MULTIPLY(z1 - z2, FIX(0.170262339)); /* (c3+c5-c1)/2 */ 4376 tmp10 = tmp11 - tmp12; 4377 tmp11 += tmp12; 4378 tmp12 = MULTIPLY(z2 + z3, - FIX(1.378756276)); /* -c1 */ 4379 tmp11 += tmp12; 4380 z2 = MULTIPLY(z1 + z3, FIX(0.613604268)); /* c5 */ 4381 tmp10 += z2; 4382 tmp12 += z2 + MULTIPLY(z3, FIX(1.870828693)); /* c3+c1-c5 */ 4383 4384 /* Final output stage */ 4385 4386 outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp20 + tmp10, 4387 CONST_BITS+PASS1_BITS+3) 4388 & RANGE_MASK]; 4389 outptr[6] = range_limit[(int) RIGHT_SHIFT(tmp20 - tmp10, 4390 CONST_BITS+PASS1_BITS+3) 4391 & RANGE_MASK]; 4392 outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp21 + tmp11, 4393 CONST_BITS+PASS1_BITS+3) 4394 & RANGE_MASK]; 4395 outptr[5] = range_limit[(int) RIGHT_SHIFT(tmp21 - tmp11, 4396 CONST_BITS+PASS1_BITS+3) 4397 & RANGE_MASK]; 4398 outptr[2] = range_limit[(int) RIGHT_SHIFT(tmp22 + tmp12, 4399 CONST_BITS+PASS1_BITS+3) 4400 & RANGE_MASK]; 4401 outptr[4] = range_limit[(int) RIGHT_SHIFT(tmp22 - tmp12, 4402 CONST_BITS+PASS1_BITS+3) 4403 & RANGE_MASK]; 4404 outptr[3] = range_limit[(int) RIGHT_SHIFT(tmp23, 4405 CONST_BITS+PASS1_BITS+3) 4406 & RANGE_MASK]; 4407 4408 wsptr += 7; /* advance pointer to next row */ 4409 } 4410 } 4411 4412 4413 /* 4414 * Perform dequantization and inverse DCT on one block of coefficients, 4415 * producing a 6x12 output block. 4416 * 4417 * 12-point IDCT in pass 1 (columns), 6-point in pass 2 (rows). 4418 */ 4419 4420 GLOBAL(void) 4421 jpeg_idct_6x12 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 4422 JCOEFPTR coef_block, 4423 JSAMPARRAY output_buf, JDIMENSION output_col) 4424 { 4425 INT32 tmp10, tmp11, tmp12, tmp13, tmp14, tmp15; 4426 INT32 tmp20, tmp21, tmp22, tmp23, tmp24, tmp25; 4427 INT32 z1, z2, z3, z4; 4428 JCOEFPTR inptr; 4429 ISLOW_MULT_TYPE * quantptr; 4430 int * wsptr; 4431 JSAMPROW outptr; 4432 JSAMPLE *range_limit = IDCT_range_limit(cinfo); 4433 int ctr; 4434 int workspace[6*12]; /* buffers data between passes */ 4435 SHIFT_TEMPS 4436 4437 /* Pass 1: process columns from input, store into work array. 4438 * 12-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/24). 4439 */ 4440 inptr = coef_block; 4441 quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 4442 wsptr = workspace; 4443 for (ctr = 0; ctr < 6; ctr++, inptr++, quantptr++, wsptr++) { 4444 /* Even part */ 4445 4446 z3 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); 4447 z3 <<= CONST_BITS; 4448 /* Add fudge factor here for final descale. */ 4449 z3 += ONE << (CONST_BITS-PASS1_BITS-1); 4450 4451 z4 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]); 4452 z4 = MULTIPLY(z4, FIX(1.224744871)); /* c4 */ 4453 4454 tmp10 = z3 + z4; 4455 tmp11 = z3 - z4; 4456 4457 z1 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]); 4458 z4 = MULTIPLY(z1, FIX(1.366025404)); /* c2 */ 4459 z1 <<= CONST_BITS; 4460 z2 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]); 4461 z2 <<= CONST_BITS; 4462 4463 tmp12 = z1 - z2; 4464 4465 tmp21 = z3 + tmp12; 4466 tmp24 = z3 - tmp12; 4467 4468 tmp12 = z4 + z2; 4469 4470 tmp20 = tmp10 + tmp12; 4471 tmp25 = tmp10 - tmp12; 4472 4473 tmp12 = z4 - z1 - z2; 4474 4475 tmp22 = tmp11 + tmp12; 4476 tmp23 = tmp11 - tmp12; 4477 4478 /* Odd part */ 4479 4480 z1 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); 4481 z2 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]); 4482 z3 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]); 4483 z4 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]); 4484 4485 tmp11 = MULTIPLY(z2, FIX(1.306562965)); /* c3 */ 4486 tmp14 = MULTIPLY(z2, - FIX_0_541196100); /* -c9 */ 4487 4488 tmp10 = z1 + z3; 4489 tmp15 = MULTIPLY(tmp10 + z4, FIX(0.860918669)); /* c7 */ 4490 tmp12 = tmp15 + MULTIPLY(tmp10, FIX(0.261052384)); /* c5-c7 */ 4491 tmp10 = tmp12 + tmp11 + MULTIPLY(z1, FIX(0.280143716)); /* c1-c5 */ 4492 tmp13 = MULTIPLY(z3 + z4, - FIX(1.045510580)); /* -(c7+c11) */ 4493 tmp12 += tmp13 + tmp14 - MULTIPLY(z3, FIX(1.478575242)); /* c1+c5-c7-c11 */ 4494 tmp13 += tmp15 - tmp11 + MULTIPLY(z4, FIX(1.586706681)); /* c1+c11 */ 4495 tmp15 += tmp14 - MULTIPLY(z1, FIX(0.676326758)) - /* c7-c11 */ 4496 MULTIPLY(z4, FIX(1.982889723)); /* c5+c7 */ 4497 4498 z1 -= z4; 4499 z2 -= z3; 4500 z3 = MULTIPLY(z1 + z2, FIX_0_541196100); /* c9 */ 4501 tmp11 = z3 + MULTIPLY(z1, FIX_0_765366865); /* c3-c9 */ 4502 tmp14 = z3 - MULTIPLY(z2, FIX_1_847759065); /* c3+c9 */ 4503 4504 /* Final output stage */ 4505 4506 wsptr[6*0] = (int) RIGHT_SHIFT(tmp20 + tmp10, CONST_BITS-PASS1_BITS); 4507 wsptr[6*11] = (int) RIGHT_SHIFT(tmp20 - tmp10, CONST_BITS-PASS1_BITS); 4508 wsptr[6*1] = (int) RIGHT_SHIFT(tmp21 + tmp11, CONST_BITS-PASS1_BITS); 4509 wsptr[6*10] = (int) RIGHT_SHIFT(tmp21 - tmp11, CONST_BITS-PASS1_BITS); 4510 wsptr[6*2] = (int) RIGHT_SHIFT(tmp22 + tmp12, CONST_BITS-PASS1_BITS); 4511 wsptr[6*9] = (int) RIGHT_SHIFT(tmp22 - tmp12, CONST_BITS-PASS1_BITS); 4512 wsptr[6*3] = (int) RIGHT_SHIFT(tmp23 + tmp13, CONST_BITS-PASS1_BITS); 4513 wsptr[6*8] = (int) RIGHT_SHIFT(tmp23 - tmp13, CONST_BITS-PASS1_BITS); 4514 wsptr[6*4] = (int) RIGHT_SHIFT(tmp24 + tmp14, CONST_BITS-PASS1_BITS); 4515 wsptr[6*7] = (int) RIGHT_SHIFT(tmp24 - tmp14, CONST_BITS-PASS1_BITS); 4516 wsptr[6*5] = (int) RIGHT_SHIFT(tmp25 + tmp15, CONST_BITS-PASS1_BITS); 4517 wsptr[6*6] = (int) RIGHT_SHIFT(tmp25 - tmp15, CONST_BITS-PASS1_BITS); 4518 } 4519 4520 /* Pass 2: process 12 rows from work array, store into output array. 4521 * 6-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/12). 4522 */ 4523 wsptr = workspace; 4524 for (ctr = 0; ctr < 12; ctr++) { 4525 outptr = output_buf[ctr] + output_col; 4526 4527 /* Even part */ 4528 4529 /* Add fudge factor here for final descale. */ 4530 tmp10 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2)); 4531 tmp10 <<= CONST_BITS; 4532 tmp12 = (INT32) wsptr[4]; 4533 tmp20 = MULTIPLY(tmp12, FIX(0.707106781)); /* c4 */ 4534 tmp11 = tmp10 + tmp20; 4535 tmp21 = tmp10 - tmp20 - tmp20; 4536 tmp20 = (INT32) wsptr[2]; 4537 tmp10 = MULTIPLY(tmp20, FIX(1.224744871)); /* c2 */ 4538 tmp20 = tmp11 + tmp10; 4539 tmp22 = tmp11 - tmp10; 4540 4541 /* Odd part */ 4542 4543 z1 = (INT32) wsptr[1]; 4544 z2 = (INT32) wsptr[3]; 4545 z3 = (INT32) wsptr[5]; 4546 tmp11 = MULTIPLY(z1 + z3, FIX(0.366025404)); /* c5 */ 4547 tmp10 = tmp11 + ((z1 + z2) << CONST_BITS); 4548 tmp12 = tmp11 + ((z3 - z2) << CONST_BITS); 4549 tmp11 = (z1 - z2 - z3) << CONST_BITS; 4550 4551 /* Final output stage */ 4552 4553 outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp20 + tmp10, 4554 CONST_BITS+PASS1_BITS+3) 4555 & RANGE_MASK]; 4556 outptr[5] = range_limit[(int) RIGHT_SHIFT(tmp20 - tmp10, 4557 CONST_BITS+PASS1_BITS+3) 4558 & RANGE_MASK]; 4559 outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp21 + tmp11, 4560 CONST_BITS+PASS1_BITS+3) 4561 & RANGE_MASK]; 4562 outptr[4] = range_limit[(int) RIGHT_SHIFT(tmp21 - tmp11, 4563 CONST_BITS+PASS1_BITS+3) 4564 & RANGE_MASK]; 4565 outptr[2] = range_limit[(int) RIGHT_SHIFT(tmp22 + tmp12, 4566 CONST_BITS+PASS1_BITS+3) 4567 & RANGE_MASK]; 4568 outptr[3] = range_limit[(int) RIGHT_SHIFT(tmp22 - tmp12, 4569 CONST_BITS+PASS1_BITS+3) 4570 & RANGE_MASK]; 4571 4572 wsptr += 6; /* advance pointer to next row */ 4573 } 4574 } 4575 4576 4577 /* 4578 * Perform dequantization and inverse DCT on one block of coefficients, 4579 * producing a 5x10 output block. 4580 * 4581 * 10-point IDCT in pass 1 (columns), 5-point in pass 2 (rows). 4582 */ 4583 4584 GLOBAL(void) 4585 jpeg_idct_5x10 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 4586 JCOEFPTR coef_block, 4587 JSAMPARRAY output_buf, JDIMENSION output_col) 4588 { 4589 INT32 tmp10, tmp11, tmp12, tmp13, tmp14; 4590 INT32 tmp20, tmp21, tmp22, tmp23, tmp24; 4591 INT32 z1, z2, z3, z4, z5; 4592 JCOEFPTR inptr; 4593 ISLOW_MULT_TYPE * quantptr; 4594 int * wsptr; 4595 JSAMPROW outptr; 4596 JSAMPLE *range_limit = IDCT_range_limit(cinfo); 4597 int ctr; 4598 int workspace[5*10]; /* buffers data between passes */ 4599 SHIFT_TEMPS 4600 4601 /* Pass 1: process columns from input, store into work array. 4602 * 10-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/20). 4603 */ 4604 inptr = coef_block; 4605 quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 4606 wsptr = workspace; 4607 for (ctr = 0; ctr < 5; ctr++, inptr++, quantptr++, wsptr++) { 4608 /* Even part */ 4609 4610 z3 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); 4611 z3 <<= CONST_BITS; 4612 /* Add fudge factor here for final descale. */ 4613 z3 += ONE << (CONST_BITS-PASS1_BITS-1); 4614 z4 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]); 4615 z1 = MULTIPLY(z4, FIX(1.144122806)); /* c4 */ 4616 z2 = MULTIPLY(z4, FIX(0.437016024)); /* c8 */ 4617 tmp10 = z3 + z1; 4618 tmp11 = z3 - z2; 4619 4620 tmp22 = RIGHT_SHIFT(z3 - ((z1 - z2) << 1), /* c0 = (c4-c8)*2 */ 4621 CONST_BITS-PASS1_BITS); 4622 4623 z2 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]); 4624 z3 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]); 4625 4626 z1 = MULTIPLY(z2 + z3, FIX(0.831253876)); /* c6 */ 4627 tmp12 = z1 + MULTIPLY(z2, FIX(0.513743148)); /* c2-c6 */ 4628 tmp13 = z1 - MULTIPLY(z3, FIX(2.176250899)); /* c2+c6 */ 4629 4630 tmp20 = tmp10 + tmp12; 4631 tmp24 = tmp10 - tmp12; 4632 tmp21 = tmp11 + tmp13; 4633 tmp23 = tmp11 - tmp13; 4634 4635 /* Odd part */ 4636 4637 z1 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); 4638 z2 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]); 4639 z3 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]); 4640 z4 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]); 4641 4642 tmp11 = z2 + z4; 4643 tmp13 = z2 - z4; 4644 4645 tmp12 = MULTIPLY(tmp13, FIX(0.309016994)); /* (c3-c7)/2 */ 4646 z5 = z3 << CONST_BITS; 4647 4648 z2 = MULTIPLY(tmp11, FIX(0.951056516)); /* (c3+c7)/2 */ 4649 z4 = z5 + tmp12; 4650 4651 tmp10 = MULTIPLY(z1, FIX(1.396802247)) + z2 + z4; /* c1 */ 4652 tmp14 = MULTIPLY(z1, FIX(0.221231742)) - z2 + z4; /* c9 */ 4653 4654 z2 = MULTIPLY(tmp11, FIX(0.587785252)); /* (c1-c9)/2 */ 4655 z4 = z5 - tmp12 - (tmp13 << (CONST_BITS - 1)); 4656 4657 tmp12 = (z1 - tmp13 - z3) << PASS1_BITS; 4658 4659 tmp11 = MULTIPLY(z1, FIX(1.260073511)) - z2 - z4; /* c3 */ 4660 tmp13 = MULTIPLY(z1, FIX(0.642039522)) - z2 + z4; /* c7 */ 4661 4662 /* Final output stage */ 4663 4664 wsptr[5*0] = (int) RIGHT_SHIFT(tmp20 + tmp10, CONST_BITS-PASS1_BITS); 4665 wsptr[5*9] = (int) RIGHT_SHIFT(tmp20 - tmp10, CONST_BITS-PASS1_BITS); 4666 wsptr[5*1] = (int) RIGHT_SHIFT(tmp21 + tmp11, CONST_BITS-PASS1_BITS); 4667 wsptr[5*8] = (int) RIGHT_SHIFT(tmp21 - tmp11, CONST_BITS-PASS1_BITS); 4668 wsptr[5*2] = (int) (tmp22 + tmp12); 4669 wsptr[5*7] = (int) (tmp22 - tmp12); 4670 wsptr[5*3] = (int) RIGHT_SHIFT(tmp23 + tmp13, CONST_BITS-PASS1_BITS); 4671 wsptr[5*6] = (int) RIGHT_SHIFT(tmp23 - tmp13, CONST_BITS-PASS1_BITS); 4672 wsptr[5*4] = (int) RIGHT_SHIFT(tmp24 + tmp14, CONST_BITS-PASS1_BITS); 4673 wsptr[5*5] = (int) RIGHT_SHIFT(tmp24 - tmp14, CONST_BITS-PASS1_BITS); 4674 } 4675 4676 /* Pass 2: process 10 rows from work array, store into output array. 4677 * 5-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/10). 4678 */ 4679 wsptr = workspace; 4680 for (ctr = 0; ctr < 10; ctr++) { 4681 outptr = output_buf[ctr] + output_col; 4682 4683 /* Even part */ 4684 4685 /* Add fudge factor here for final descale. */ 4686 tmp12 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2)); 4687 tmp12 <<= CONST_BITS; 4688 tmp13 = (INT32) wsptr[2]; 4689 tmp14 = (INT32) wsptr[4]; 4690 z1 = MULTIPLY(tmp13 + tmp14, FIX(0.790569415)); /* (c2+c4)/2 */ 4691 z2 = MULTIPLY(tmp13 - tmp14, FIX(0.353553391)); /* (c2-c4)/2 */ 4692 z3 = tmp12 + z2; 4693 tmp10 = z3 + z1; 4694 tmp11 = z3 - z1; 4695 tmp12 -= z2 << 2; 4696 4697 /* Odd part */ 4698 4699 z2 = (INT32) wsptr[1]; 4700 z3 = (INT32) wsptr[3]; 4701 4702 z1 = MULTIPLY(z2 + z3, FIX(0.831253876)); /* c3 */ 4703 tmp13 = z1 + MULTIPLY(z2, FIX(0.513743148)); /* c1-c3 */ 4704 tmp14 = z1 - MULTIPLY(z3, FIX(2.176250899)); /* c1+c3 */ 4705 4706 /* Final output stage */ 4707 4708 outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp10 + tmp13, 4709 CONST_BITS+PASS1_BITS+3) 4710 & RANGE_MASK]; 4711 outptr[4] = range_limit[(int) RIGHT_SHIFT(tmp10 - tmp13, 4712 CONST_BITS+PASS1_BITS+3) 4713 & RANGE_MASK]; 4714 outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp11 + tmp14, 4715 CONST_BITS+PASS1_BITS+3) 4716 & RANGE_MASK]; 4717 outptr[3] = range_limit[(int) RIGHT_SHIFT(tmp11 - tmp14, 4718 CONST_BITS+PASS1_BITS+3) 4719 & RANGE_MASK]; 4720 outptr[2] = range_limit[(int) RIGHT_SHIFT(tmp12, 4721 CONST_BITS+PASS1_BITS+3) 4722 & RANGE_MASK]; 4723 4724 wsptr += 5; /* advance pointer to next row */ 4725 } 4726 } 4727 4728 4729 /* 4730 * Perform dequantization and inverse DCT on one block of coefficients, 4731 * producing a 4x8 output block. 4732 * 4733 * 8-point IDCT in pass 1 (columns), 4-point in pass 2 (rows). 4734 */ 4735 4736 GLOBAL(void) 4737 jpeg_idct_4x8 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 4738 JCOEFPTR coef_block, 4739 JSAMPARRAY output_buf, JDIMENSION output_col) 4740 { 4741 INT32 tmp0, tmp1, tmp2, tmp3; 4742 INT32 tmp10, tmp11, tmp12, tmp13; 4743 INT32 z1, z2, z3; 4744 JCOEFPTR inptr; 4745 ISLOW_MULT_TYPE * quantptr; 4746 int * wsptr; 4747 JSAMPROW outptr; 4748 JSAMPLE *range_limit = IDCT_range_limit(cinfo); 4749 int ctr; 4750 int workspace[4*8]; /* buffers data between passes */ 4751 SHIFT_TEMPS 4752 4753 /* Pass 1: process columns from input, store into work array. */ 4754 /* Note results are scaled up by sqrt(8) compared to a true IDCT; */ 4755 /* furthermore, we scale the results by 2**PASS1_BITS. */ 4756 4757 inptr = coef_block; 4758 quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 4759 wsptr = workspace; 4760 for (ctr = 4; ctr > 0; ctr--) { 4761 /* Due to quantization, we will usually find that many of the input 4762 * coefficients are zero, especially the AC terms. We can exploit this 4763 * by short-circuiting the IDCT calculation for any column in which all 4764 * the AC terms are zero. In that case each output is equal to the 4765 * DC coefficient (with scale factor as needed). 4766 * With typical images and quantization tables, half or more of the 4767 * column DCT calculations can be simplified this way. 4768 */ 4769 4770 if (inptr[DCTSIZE*1] == 0 && inptr[DCTSIZE*2] == 0 && 4771 inptr[DCTSIZE*3] == 0 && inptr[DCTSIZE*4] == 0 && 4772 inptr[DCTSIZE*5] == 0 && inptr[DCTSIZE*6] == 0 && 4773 inptr[DCTSIZE*7] == 0) { 4774 /* AC terms all zero */ 4775 int dcval = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]) << PASS1_BITS; 4776 4777 wsptr[4*0] = dcval; 4778 wsptr[4*1] = dcval; 4779 wsptr[4*2] = dcval; 4780 wsptr[4*3] = dcval; 4781 wsptr[4*4] = dcval; 4782 wsptr[4*5] = dcval; 4783 wsptr[4*6] = dcval; 4784 wsptr[4*7] = dcval; 4785 4786 inptr++; /* advance pointers to next column */ 4787 quantptr++; 4788 wsptr++; 4789 continue; 4790 } 4791 4792 /* Even part: reverse the even part of the forward DCT. */ 4793 /* The rotator is sqrt(2)*c(-6). */ 4794 4795 z2 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]); 4796 z3 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]); 4797 4798 z1 = MULTIPLY(z2 + z3, FIX_0_541196100); 4799 tmp2 = z1 + MULTIPLY(z2, FIX_0_765366865); 4800 tmp3 = z1 - MULTIPLY(z3, FIX_1_847759065); 4801 4802 z2 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); 4803 z3 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]); 4804 z2 <<= CONST_BITS; 4805 z3 <<= CONST_BITS; 4806 /* Add fudge factor here for final descale. */ 4807 z2 += ONE << (CONST_BITS-PASS1_BITS-1); 4808 4809 tmp0 = z2 + z3; 4810 tmp1 = z2 - z3; 4811 4812 tmp10 = tmp0 + tmp2; 4813 tmp13 = tmp0 - tmp2; 4814 tmp11 = tmp1 + tmp3; 4815 tmp12 = tmp1 - tmp3; 4816 4817 /* Odd part per figure 8; the matrix is unitary and hence its 4818 * transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively. 4819 */ 4820 4821 tmp0 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]); 4822 tmp1 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]); 4823 tmp2 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]); 4824 tmp3 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); 4825 4826 z2 = tmp0 + tmp2; 4827 z3 = tmp1 + tmp3; 4828 4829 z1 = MULTIPLY(z2 + z3, FIX_1_175875602); /* sqrt(2) * c3 */ 4830 z2 = MULTIPLY(z2, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */ 4831 z3 = MULTIPLY(z3, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */ 4832 z2 += z1; 4833 z3 += z1; 4834 4835 z1 = MULTIPLY(tmp0 + tmp3, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */ 4836 tmp0 = MULTIPLY(tmp0, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */ 4837 tmp3 = MULTIPLY(tmp3, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */ 4838 tmp0 += z1 + z2; 4839 tmp3 += z1 + z3; 4840 4841 z1 = MULTIPLY(tmp1 + tmp2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */ 4842 tmp1 = MULTIPLY(tmp1, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */ 4843 tmp2 = MULTIPLY(tmp2, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */ 4844 tmp1 += z1 + z3; 4845 tmp2 += z1 + z2; 4846 4847 /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */ 4848 4849 wsptr[4*0] = (int) RIGHT_SHIFT(tmp10 + tmp3, CONST_BITS-PASS1_BITS); 4850 wsptr[4*7] = (int) RIGHT_SHIFT(tmp10 - tmp3, CONST_BITS-PASS1_BITS); 4851 wsptr[4*1] = (int) RIGHT_SHIFT(tmp11 + tmp2, CONST_BITS-PASS1_BITS); 4852 wsptr[4*6] = (int) RIGHT_SHIFT(tmp11 - tmp2, CONST_BITS-PASS1_BITS); 4853 wsptr[4*2] = (int) RIGHT_SHIFT(tmp12 + tmp1, CONST_BITS-PASS1_BITS); 4854 wsptr[4*5] = (int) RIGHT_SHIFT(tmp12 - tmp1, CONST_BITS-PASS1_BITS); 4855 wsptr[4*3] = (int) RIGHT_SHIFT(tmp13 + tmp0, CONST_BITS-PASS1_BITS); 4856 wsptr[4*4] = (int) RIGHT_SHIFT(tmp13 - tmp0, CONST_BITS-PASS1_BITS); 4857 4858 inptr++; /* advance pointers to next column */ 4859 quantptr++; 4860 wsptr++; 4861 } 4862 4863 /* Pass 2: process 8 rows from work array, store into output array. 4864 * 4-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/16). 4865 */ 4866 wsptr = workspace; 4867 for (ctr = 0; ctr < 8; ctr++) { 4868 outptr = output_buf[ctr] + output_col; 4869 4870 /* Even part */ 4871 4872 /* Add fudge factor here for final descale. */ 4873 tmp0 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2)); 4874 tmp2 = (INT32) wsptr[2]; 4875 4876 tmp10 = (tmp0 + tmp2) << CONST_BITS; 4877 tmp12 = (tmp0 - tmp2) << CONST_BITS; 4878 4879 /* Odd part */ 4880 /* Same rotation as in the even part of the 8x8 LL&M IDCT */ 4881 4882 z2 = (INT32) wsptr[1]; 4883 z3 = (INT32) wsptr[3]; 4884 4885 z1 = MULTIPLY(z2 + z3, FIX_0_541196100); /* c6 */ 4886 tmp0 = z1 + MULTIPLY(z2, FIX_0_765366865); /* c2-c6 */ 4887 tmp2 = z1 - MULTIPLY(z3, FIX_1_847759065); /* c2+c6 */ 4888 4889 /* Final output stage */ 4890 4891 outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp10 + tmp0, 4892 CONST_BITS+PASS1_BITS+3) 4893 & RANGE_MASK]; 4894 outptr[3] = range_limit[(int) RIGHT_SHIFT(tmp10 - tmp0, 4895 CONST_BITS+PASS1_BITS+3) 4896 & RANGE_MASK]; 4897 outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp12 + tmp2, 4898 CONST_BITS+PASS1_BITS+3) 4899 & RANGE_MASK]; 4900 outptr[2] = range_limit[(int) RIGHT_SHIFT(tmp12 - tmp2, 4901 CONST_BITS+PASS1_BITS+3) 4902 & RANGE_MASK]; 4903 4904 wsptr += 4; /* advance pointer to next row */ 4905 } 4906 } 4907 4908 4909 /* 4910 * Perform dequantization and inverse DCT on one block of coefficients, 4911 * producing a reduced-size 3x6 output block. 4912 * 4913 * 6-point IDCT in pass 1 (columns), 3-point in pass 2 (rows). 4914 */ 4915 4916 GLOBAL(void) 4917 jpeg_idct_3x6 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 4918 JCOEFPTR coef_block, 4919 JSAMPARRAY output_buf, JDIMENSION output_col) 4920 { 4921 INT32 tmp0, tmp1, tmp2, tmp10, tmp11, tmp12; 4922 INT32 z1, z2, z3; 4923 JCOEFPTR inptr; 4924 ISLOW_MULT_TYPE * quantptr; 4925 int * wsptr; 4926 JSAMPROW outptr; 4927 JSAMPLE *range_limit = IDCT_range_limit(cinfo); 4928 int ctr; 4929 int workspace[3*6]; /* buffers data between passes */ 4930 SHIFT_TEMPS 4931 4932 /* Pass 1: process columns from input, store into work array. 4933 * 6-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/12). 4934 */ 4935 inptr = coef_block; 4936 quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 4937 wsptr = workspace; 4938 for (ctr = 0; ctr < 3; ctr++, inptr++, quantptr++, wsptr++) { 4939 /* Even part */ 4940 4941 tmp0 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); 4942 tmp0 <<= CONST_BITS; 4943 /* Add fudge factor here for final descale. */ 4944 tmp0 += ONE << (CONST_BITS-PASS1_BITS-1); 4945 tmp2 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]); 4946 tmp10 = MULTIPLY(tmp2, FIX(0.707106781)); /* c4 */ 4947 tmp1 = tmp0 + tmp10; 4948 tmp11 = RIGHT_SHIFT(tmp0 - tmp10 - tmp10, CONST_BITS-PASS1_BITS); 4949 tmp10 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]); 4950 tmp0 = MULTIPLY(tmp10, FIX(1.224744871)); /* c2 */ 4951 tmp10 = tmp1 + tmp0; 4952 tmp12 = tmp1 - tmp0; 4953 4954 /* Odd part */ 4955 4956 z1 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); 4957 z2 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]); 4958 z3 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]); 4959 tmp1 = MULTIPLY(z1 + z3, FIX(0.366025404)); /* c5 */ 4960 tmp0 = tmp1 + ((z1 + z2) << CONST_BITS); 4961 tmp2 = tmp1 + ((z3 - z2) << CONST_BITS); 4962 tmp1 = (z1 - z2 - z3) << PASS1_BITS; 4963 4964 /* Final output stage */ 4965 4966 wsptr[3*0] = (int) RIGHT_SHIFT(tmp10 + tmp0, CONST_BITS-PASS1_BITS); 4967 wsptr[3*5] = (int) RIGHT_SHIFT(tmp10 - tmp0, CONST_BITS-PASS1_BITS); 4968 wsptr[3*1] = (int) (tmp11 + tmp1); 4969 wsptr[3*4] = (int) (tmp11 - tmp1); 4970 wsptr[3*2] = (int) RIGHT_SHIFT(tmp12 + tmp2, CONST_BITS-PASS1_BITS); 4971 wsptr[3*3] = (int) RIGHT_SHIFT(tmp12 - tmp2, CONST_BITS-PASS1_BITS); 4972 } 4973 4974 /* Pass 2: process 6 rows from work array, store into output array. 4975 * 3-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/6). 4976 */ 4977 wsptr = workspace; 4978 for (ctr = 0; ctr < 6; ctr++) { 4979 outptr = output_buf[ctr] + output_col; 4980 4981 /* Even part */ 4982 4983 /* Add fudge factor here for final descale. */ 4984 tmp0 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2)); 4985 tmp0 <<= CONST_BITS; 4986 tmp2 = (INT32) wsptr[2]; 4987 tmp12 = MULTIPLY(tmp2, FIX(0.707106781)); /* c2 */ 4988 tmp10 = tmp0 + tmp12; 4989 tmp2 = tmp0 - tmp12 - tmp12; 4990 4991 /* Odd part */ 4992 4993 tmp12 = (INT32) wsptr[1]; 4994 tmp0 = MULTIPLY(tmp12, FIX(1.224744871)); /* c1 */ 4995 4996 /* Final output stage */ 4997 4998 outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp10 + tmp0, 4999 CONST_BITS+PASS1_BITS+3) 5000 & RANGE_MASK]; 5001 outptr[2] = range_limit[(int) RIGHT_SHIFT(tmp10 - tmp0, 5002 CONST_BITS+PASS1_BITS+3) 5003 & RANGE_MASK]; 5004 outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp2, 5005 CONST_BITS+PASS1_BITS+3) 5006 & RANGE_MASK]; 5007 5008 wsptr += 3; /* advance pointer to next row */ 5009 } 5010 } 5011 5012 5013 /* 5014 * Perform dequantization and inverse DCT on one block of coefficients, 5015 * producing a 2x4 output block. 5016 * 5017 * 4-point IDCT in pass 1 (columns), 2-point in pass 2 (rows). 5018 */ 5019 5020 GLOBAL(void) 5021 jpeg_idct_2x4 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 5022 JCOEFPTR coef_block, 5023 JSAMPARRAY output_buf, JDIMENSION output_col) 5024 { 5025 INT32 tmp0, tmp2, tmp10, tmp12; 5026 INT32 z1, z2, z3; 5027 JCOEFPTR inptr; 5028 ISLOW_MULT_TYPE * quantptr; 5029 INT32 * wsptr; 5030 JSAMPROW outptr; 5031 JSAMPLE *range_limit = IDCT_range_limit(cinfo); 5032 int ctr; 5033 INT32 workspace[2*4]; /* buffers data between passes */ 5034 SHIFT_TEMPS 5035 5036 /* Pass 1: process columns from input, store into work array. 5037 * 4-point IDCT kernel, 5038 * cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point IDCT]. 5039 */ 5040 inptr = coef_block; 5041 quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 5042 wsptr = workspace; 5043 for (ctr = 0; ctr < 2; ctr++, inptr++, quantptr++, wsptr++) { 5044 /* Even part */ 5045 5046 tmp0 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); 5047 tmp2 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]); 5048 5049 tmp10 = (tmp0 + tmp2) << CONST_BITS; 5050 tmp12 = (tmp0 - tmp2) << CONST_BITS; 5051 5052 /* Odd part */ 5053 /* Same rotation as in the even part of the 8x8 LL&M IDCT */ 5054 5055 z2 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); 5056 z3 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]); 5057 5058 z1 = MULTIPLY(z2 + z3, FIX_0_541196100); /* c6 */ 5059 tmp0 = z1 + MULTIPLY(z2, FIX_0_765366865); /* c2-c6 */ 5060 tmp2 = z1 - MULTIPLY(z3, FIX_1_847759065); /* c2+c6 */ 5061 5062 /* Final output stage */ 5063 5064 wsptr[2*0] = tmp10 + tmp0; 5065 wsptr[2*3] = tmp10 - tmp0; 5066 wsptr[2*1] = tmp12 + tmp2; 5067 wsptr[2*2] = tmp12 - tmp2; 5068 } 5069 5070 /* Pass 2: process 4 rows from work array, store into output array. */ 5071 5072 wsptr = workspace; 5073 for (ctr = 0; ctr < 4; ctr++) { 5074 outptr = output_buf[ctr] + output_col; 5075 5076 /* Even part */ 5077 5078 /* Add fudge factor here for final descale. */ 5079 tmp10 = wsptr[0] + (ONE << (CONST_BITS+2)); 5080 5081 /* Odd part */ 5082 5083 tmp0 = wsptr[1]; 5084 5085 /* Final output stage */ 5086 5087 outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp10 + tmp0, CONST_BITS+3) 5088 & RANGE_MASK]; 5089 outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp10 - tmp0, CONST_BITS+3) 5090 & RANGE_MASK]; 5091 5092 wsptr += 2; /* advance pointer to next row */ 5093 } 5094 } 5095 5096 5097 /* 5098 * Perform dequantization and inverse DCT on one block of coefficients, 5099 * producing a 1x2 output block. 5100 * 5101 * 2-point IDCT in pass 1 (columns), 1-point in pass 2 (rows). 5102 */ 5103 5104 GLOBAL(void) 5105 jpeg_idct_1x2 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 5106 JCOEFPTR coef_block, 5107 JSAMPARRAY output_buf, JDIMENSION output_col) 5108 { 5109 INT32 tmp0, tmp10; 5110 ISLOW_MULT_TYPE * quantptr; 5111 JSAMPLE *range_limit = IDCT_range_limit(cinfo); 5112 SHIFT_TEMPS 5113 5114 /* Process 1 column from input, store into output array. */ 5115 5116 quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 5117 5118 /* Even part */ 5119 5120 tmp10 = DEQUANTIZE(coef_block[DCTSIZE*0], quantptr[DCTSIZE*0]); 5121 /* Add fudge factor here for final descale. */ 5122 tmp10 += ONE << 2; 5123 5124 /* Odd part */ 5125 5126 tmp0 = DEQUANTIZE(coef_block[DCTSIZE*1], quantptr[DCTSIZE*1]); 5127 5128 /* Final output stage */ 5129 5130 output_buf[0][output_col] = range_limit[(int) RIGHT_SHIFT(tmp10 + tmp0, 3) 5131 & RANGE_MASK]; 5132 output_buf[1][output_col] = range_limit[(int) RIGHT_SHIFT(tmp10 - tmp0, 3) 5133 & RANGE_MASK]; 5134 } 5135 5136 #endif /* IDCT_SCALING_SUPPORTED */ 5137 #endif /* DCT_ISLOW_SUPPORTED */ 5138
