4 * Copyright (C) 1991-1996, Thomas G. Lane.
5 * Modification developed 2003-2013 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.
9 * This file contains a slow-but-accurate integer implementation of the
10 * forward DCT (Discrete Cosine Transform).
12 * A 2-D DCT can be done by 1-D DCT on each row followed by 1-D DCT
13 * on each column. Direct algorithms are also available, but they are
14 * much more complex and seem not to be any faster when reduced to code.
16 * This implementation is based on an algorithm described in
17 * C. Loeffler, A. Ligtenberg and G. Moschytz, "Practical Fast 1-D DCT
18 * Algorithms with 11 Multiplications", Proc. Int'l. Conf. on Acoustics,
19 * Speech, and Signal Processing 1989 (ICASSP '89), pp. 988-991.
20 * The primary algorithm described there uses 11 multiplies and 29 adds.
21 * We use their alternate method with 12 multiplies and 32 adds.
22 * The advantage of this method is that no data path contains more than one
23 * multiplication; this allows a very simple and accurate implementation in
24 * scaled fixed-point arithmetic, with a minimal number of shifts.
26 * We also provide FDCT routines with various input sample block sizes for
27 * direct resolution reduction or enlargement and for direct resolving the
28 * common 2x1 and 1x2 subsampling cases without additional resampling: NxN
29 * (N=1...16), 2NxN, and Nx2N (N=1...8) pixels for one 8x8 output DCT block.
31 * For N<8 we fill the remaining block coefficients with zero.
32 * For N>8 we apply a partial N-point FDCT on the input samples, computing
33 * just the lower 8 frequency coefficients and discarding the rest.
35 * We must scale the output coefficients of the N-point FDCT appropriately
36 * to the standard 8-point FDCT level by 8/N per 1-D pass. This scaling
37 * is folded into the constant multipliers (pass 2) and/or final/initial
40 * CAUTION: We rely on the FIX() macro except for the N=1,2,4,8 cases
41 * since there would be too many additional constants to pre-calculate.
44 #define JPEG_INTERNALS
47 #include "jdct.h" /* Private declarations for DCT subsystem */
49 #ifdef DCT_ISLOW_SUPPORTED
53 * This module is specialized to the case DCTSIZE = 8.
57 Sorry
, this code only copes with
8x8 DCT blocks
. /* deliberate syntax err */
62 * The poop on this scaling stuff is as follows:
64 * Each 1-D DCT step produces outputs which are a factor of sqrt(N)
65 * larger than the true DCT outputs. The final outputs are therefore
66 * a factor of N larger than desired; since N=8 this can be cured by
67 * a simple right shift at the end of the algorithm. The advantage of
68 * this arrangement is that we save two multiplications per 1-D DCT,
69 * because the y0 and y4 outputs need not be divided by sqrt(N).
70 * In the IJG code, this factor of 8 is removed by the quantization step
71 * (in jcdctmgr.c), NOT in this module.
73 * We have to do addition and subtraction of the integer inputs, which
74 * is no problem, and multiplication by fractional constants, which is
75 * a problem to do in integer arithmetic. We multiply all the constants
76 * by CONST_SCALE and convert them to integer constants (thus retaining
77 * CONST_BITS bits of precision in the constants). After doing a
78 * multiplication we have to divide the product by CONST_SCALE, with proper
79 * rounding, to produce the correct output. This division can be done
80 * cheaply as a right shift of CONST_BITS bits. We postpone shifting
81 * as long as possible so that partial sums can be added together with
82 * full fractional precision.
84 * The outputs of the first pass are scaled up by PASS1_BITS bits so that
85 * they are represented to better-than-integral precision. These outputs
86 * require BITS_IN_JSAMPLE + PASS1_BITS + 3 bits; this fits in a 16-bit word
87 * with the recommended scaling. (For 12-bit sample data, the intermediate
88 * array is INT32 anyway.)
90 * To avoid overflow of the 32-bit intermediate results in pass 2, we must
91 * have BITS_IN_JSAMPLE + CONST_BITS + PASS1_BITS <= 26. Error analysis
92 * shows that the values given below are the most effective.
95 #if BITS_IN_JSAMPLE == 8
100 #define PASS1_BITS 1 /* lose a little precision to avoid overflow */
103 /* Some C compilers fail to reduce "FIX(constant)" at compile time, thus
104 * causing a lot of useless floating-point operations at run time.
105 * To get around this we use the following pre-calculated constants.
106 * If you change CONST_BITS you may want to add appropriate values.
107 * (With a reasonable C compiler, you can just rely on the FIX() macro...)
111 #define FIX_0_298631336 ((INT32) 2446) /* FIX(0.298631336) */
112 #define FIX_0_390180644 ((INT32) 3196) /* FIX(0.390180644) */
113 #define FIX_0_541196100 ((INT32) 4433) /* FIX(0.541196100) */
114 #define FIX_0_765366865 ((INT32) 6270) /* FIX(0.765366865) */
115 #define FIX_0_899976223 ((INT32) 7373) /* FIX(0.899976223) */
116 #define FIX_1_175875602 ((INT32) 9633) /* FIX(1.175875602) */
117 #define FIX_1_501321110 ((INT32) 12299) /* FIX(1.501321110) */
118 #define FIX_1_847759065 ((INT32) 15137) /* FIX(1.847759065) */
119 #define FIX_1_961570560 ((INT32) 16069) /* FIX(1.961570560) */
120 #define FIX_2_053119869 ((INT32) 16819) /* FIX(2.053119869) */
121 #define FIX_2_562915447 ((INT32) 20995) /* FIX(2.562915447) */
122 #define FIX_3_072711026 ((INT32) 25172) /* FIX(3.072711026) */
124 #define FIX_0_298631336 FIX(0.298631336)
125 #define FIX_0_390180644 FIX(0.390180644)
126 #define FIX_0_541196100 FIX(0.541196100)
127 #define FIX_0_765366865 FIX(0.765366865)
128 #define FIX_0_899976223 FIX(0.899976223)
129 #define FIX_1_175875602 FIX(1.175875602)
130 #define FIX_1_501321110 FIX(1.501321110)
131 #define FIX_1_847759065 FIX(1.847759065)
132 #define FIX_1_961570560 FIX(1.961570560)
133 #define FIX_2_053119869 FIX(2.053119869)
134 #define FIX_2_562915447 FIX(2.562915447)
135 #define FIX_3_072711026 FIX(3.072711026)
139 /* Multiply an INT32 variable by an INT32 constant to yield an INT32 result.
140 * For 8-bit samples with the recommended scaling, all the variable
141 * and constant values involved are no more than 16 bits wide, so a
142 * 16x16->32 bit multiply can be used instead of a full 32x32 multiply.
143 * For 12-bit samples, a full 32-bit multiplication will be needed.
146 #if BITS_IN_JSAMPLE == 8
147 #define MULTIPLY(var,const) MULTIPLY16C16(var,const)
149 #define MULTIPLY(var,const) ((var) * (const))
154 * Perform the forward DCT on one block of samples.
158 jpeg_fdct_islow (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
160 INT32 tmp0
, tmp1
, tmp2
, tmp3
;
161 INT32 tmp10
, tmp11
, tmp12
, tmp13
;
168 /* Pass 1: process rows.
169 * Note results are scaled up by sqrt(8) compared to a true DCT;
170 * furthermore, we scale the results by 2**PASS1_BITS.
171 * cK represents sqrt(2) * cos(K*pi/16).
175 for (ctr
= 0; ctr
< DCTSIZE
; ctr
++) {
176 elemptr
= sample_data
[ctr
] + start_col
;
178 /* Even part per LL&M figure 1 --- note that published figure is faulty;
179 * rotator "c1" should be "c6".
182 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[7]);
183 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[6]);
184 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[5]);
185 tmp3
= GETJSAMPLE(elemptr
[3]) + GETJSAMPLE(elemptr
[4]);
192 tmp0
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[7]);
193 tmp1
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[6]);
194 tmp2
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[5]);
195 tmp3
= GETJSAMPLE(elemptr
[3]) - GETJSAMPLE(elemptr
[4]);
197 /* Apply unsigned->signed conversion */
198 dataptr
[0] = (DCTELEM
) ((tmp10
+ tmp11
- 8 * CENTERJSAMPLE
) << PASS1_BITS
);
199 dataptr
[4] = (DCTELEM
) ((tmp10
- tmp11
) << PASS1_BITS
);
201 z1
= MULTIPLY(tmp12
+ tmp13
, FIX_0_541196100
); /* c6 */
202 /* Add fudge factor here for final descale. */
203 z1
+= ONE
<< (CONST_BITS
-PASS1_BITS
-1);
205 dataptr
[2] = (DCTELEM
)
206 RIGHT_SHIFT(z1
+ MULTIPLY(tmp12
, FIX_0_765366865
), /* c2-c6 */
207 CONST_BITS
-PASS1_BITS
);
208 dataptr
[6] = (DCTELEM
)
209 RIGHT_SHIFT(z1
- MULTIPLY(tmp13
, FIX_1_847759065
), /* c2+c6 */
210 CONST_BITS
-PASS1_BITS
);
212 /* Odd part per figure 8 --- note paper omits factor of sqrt(2).
213 * i0..i3 in the paper are tmp0..tmp3 here.
219 z1
= MULTIPLY(tmp12
+ tmp13
, FIX_1_175875602
); /* c3 */
220 /* Add fudge factor here for final descale. */
221 z1
+= ONE
<< (CONST_BITS
-PASS1_BITS
-1);
223 tmp12
= MULTIPLY(tmp12
, - FIX_0_390180644
); /* -c3+c5 */
224 tmp13
= MULTIPLY(tmp13
, - FIX_1_961570560
); /* -c3-c5 */
228 z1
= MULTIPLY(tmp0
+ tmp3
, - FIX_0_899976223
); /* -c3+c7 */
229 tmp0
= MULTIPLY(tmp0
, FIX_1_501321110
); /* c1+c3-c5-c7 */
230 tmp3
= MULTIPLY(tmp3
, FIX_0_298631336
); /* -c1+c3+c5-c7 */
234 z1
= MULTIPLY(tmp1
+ tmp2
, - FIX_2_562915447
); /* -c1-c3 */
235 tmp1
= MULTIPLY(tmp1
, FIX_3_072711026
); /* c1+c3+c5-c7 */
236 tmp2
= MULTIPLY(tmp2
, FIX_2_053119869
); /* c1+c3-c5+c7 */
240 dataptr
[1] = (DCTELEM
) RIGHT_SHIFT(tmp0
, CONST_BITS
-PASS1_BITS
);
241 dataptr
[3] = (DCTELEM
) RIGHT_SHIFT(tmp1
, CONST_BITS
-PASS1_BITS
);
242 dataptr
[5] = (DCTELEM
) RIGHT_SHIFT(tmp2
, CONST_BITS
-PASS1_BITS
);
243 dataptr
[7] = (DCTELEM
) RIGHT_SHIFT(tmp3
, CONST_BITS
-PASS1_BITS
);
245 dataptr
+= DCTSIZE
; /* advance pointer to next row */
248 /* Pass 2: process columns.
249 * We remove the PASS1_BITS scaling, but leave the results scaled up
250 * by an overall factor of 8.
251 * cK represents sqrt(2) * cos(K*pi/16).
255 for (ctr
= DCTSIZE
-1; ctr
>= 0; ctr
--) {
256 /* Even part per LL&M figure 1 --- note that published figure is faulty;
257 * rotator "c1" should be "c6".
260 tmp0
= dataptr
[DCTSIZE
*0] + dataptr
[DCTSIZE
*7];
261 tmp1
= dataptr
[DCTSIZE
*1] + dataptr
[DCTSIZE
*6];
262 tmp2
= dataptr
[DCTSIZE
*2] + dataptr
[DCTSIZE
*5];
263 tmp3
= dataptr
[DCTSIZE
*3] + dataptr
[DCTSIZE
*4];
265 /* Add fudge factor here for final descale. */
266 tmp10
= tmp0
+ tmp3
+ (ONE
<< (PASS1_BITS
-1));
271 tmp0
= dataptr
[DCTSIZE
*0] - dataptr
[DCTSIZE
*7];
272 tmp1
= dataptr
[DCTSIZE
*1] - dataptr
[DCTSIZE
*6];
273 tmp2
= dataptr
[DCTSIZE
*2] - dataptr
[DCTSIZE
*5];
274 tmp3
= dataptr
[DCTSIZE
*3] - dataptr
[DCTSIZE
*4];
276 dataptr
[DCTSIZE
*0] = (DCTELEM
) RIGHT_SHIFT(tmp10
+ tmp11
, PASS1_BITS
);
277 dataptr
[DCTSIZE
*4] = (DCTELEM
) RIGHT_SHIFT(tmp10
- tmp11
, PASS1_BITS
);
279 z1
= MULTIPLY(tmp12
+ tmp13
, FIX_0_541196100
); /* c6 */
280 /* Add fudge factor here for final descale. */
281 z1
+= ONE
<< (CONST_BITS
+PASS1_BITS
-1);
283 dataptr
[DCTSIZE
*2] = (DCTELEM
)
284 RIGHT_SHIFT(z1
+ MULTIPLY(tmp12
, FIX_0_765366865
), /* c2-c6 */
285 CONST_BITS
+PASS1_BITS
);
286 dataptr
[DCTSIZE
*6] = (DCTELEM
)
287 RIGHT_SHIFT(z1
- MULTIPLY(tmp13
, FIX_1_847759065
), /* c2+c6 */
288 CONST_BITS
+PASS1_BITS
);
290 /* Odd part per figure 8 --- note paper omits factor of sqrt(2).
291 * i0..i3 in the paper are tmp0..tmp3 here.
297 z1
= MULTIPLY(tmp12
+ tmp13
, FIX_1_175875602
); /* c3 */
298 /* Add fudge factor here for final descale. */
299 z1
+= ONE
<< (CONST_BITS
+PASS1_BITS
-1);
301 tmp12
= MULTIPLY(tmp12
, - FIX_0_390180644
); /* -c3+c5 */
302 tmp13
= MULTIPLY(tmp13
, - FIX_1_961570560
); /* -c3-c5 */
306 z1
= MULTIPLY(tmp0
+ tmp3
, - FIX_0_899976223
); /* -c3+c7 */
307 tmp0
= MULTIPLY(tmp0
, FIX_1_501321110
); /* c1+c3-c5-c7 */
308 tmp3
= MULTIPLY(tmp3
, FIX_0_298631336
); /* -c1+c3+c5-c7 */
312 z1
= MULTIPLY(tmp1
+ tmp2
, - FIX_2_562915447
); /* -c1-c3 */
313 tmp1
= MULTIPLY(tmp1
, FIX_3_072711026
); /* c1+c3+c5-c7 */
314 tmp2
= MULTIPLY(tmp2
, FIX_2_053119869
); /* c1+c3-c5+c7 */
318 dataptr
[DCTSIZE
*1] = (DCTELEM
) RIGHT_SHIFT(tmp0
, CONST_BITS
+PASS1_BITS
);
319 dataptr
[DCTSIZE
*3] = (DCTELEM
) RIGHT_SHIFT(tmp1
, CONST_BITS
+PASS1_BITS
);
320 dataptr
[DCTSIZE
*5] = (DCTELEM
) RIGHT_SHIFT(tmp2
, CONST_BITS
+PASS1_BITS
);
321 dataptr
[DCTSIZE
*7] = (DCTELEM
) RIGHT_SHIFT(tmp3
, CONST_BITS
+PASS1_BITS
);
323 dataptr
++; /* advance pointer to next column */
327 #ifdef DCT_SCALING_SUPPORTED
331 * Perform the forward DCT on a 7x7 sample block.
335 jpeg_fdct_7x7 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
337 INT32 tmp0
, tmp1
, tmp2
, tmp3
;
338 INT32 tmp10
, tmp11
, tmp12
;
345 /* Pre-zero output coefficient block. */
346 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
348 /* Pass 1: process rows.
349 * Note results are scaled up by sqrt(8) compared to a true DCT;
350 * furthermore, we scale the results by 2**PASS1_BITS.
351 * cK represents sqrt(2) * cos(K*pi/14).
355 for (ctr
= 0; ctr
< 7; ctr
++) {
356 elemptr
= sample_data
[ctr
] + start_col
;
360 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[6]);
361 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[5]);
362 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[4]);
363 tmp3
= GETJSAMPLE(elemptr
[3]);
365 tmp10
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[6]);
366 tmp11
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[5]);
367 tmp12
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[4]);
370 /* Apply unsigned->signed conversion */
371 dataptr
[0] = (DCTELEM
)
372 ((z1
+ tmp1
+ tmp3
- 7 * CENTERJSAMPLE
) << PASS1_BITS
);
376 z1
= MULTIPLY(z1
, FIX(0.353553391)); /* (c2+c6-c4)/2 */
377 z2
= MULTIPLY(tmp0
- tmp2
, FIX(0.920609002)); /* (c2+c4-c6)/2 */
378 z3
= MULTIPLY(tmp1
- tmp2
, FIX(0.314692123)); /* c6 */
379 dataptr
[2] = (DCTELEM
) DESCALE(z1
+ z2
+ z3
, CONST_BITS
-PASS1_BITS
);
381 z2
= MULTIPLY(tmp0
- tmp1
, FIX(0.881747734)); /* c4 */
382 dataptr
[4] = (DCTELEM
)
383 DESCALE(z2
+ z3
- MULTIPLY(tmp1
- tmp3
, FIX(0.707106781)), /* c2+c6-c4 */
384 CONST_BITS
-PASS1_BITS
);
385 dataptr
[6] = (DCTELEM
) DESCALE(z1
+ z2
, CONST_BITS
-PASS1_BITS
);
389 tmp1
= MULTIPLY(tmp10
+ tmp11
, FIX(0.935414347)); /* (c3+c1-c5)/2 */
390 tmp2
= MULTIPLY(tmp10
- tmp11
, FIX(0.170262339)); /* (c3+c5-c1)/2 */
393 tmp2
= MULTIPLY(tmp11
+ tmp12
, - FIX(1.378756276)); /* -c1 */
395 tmp3
= MULTIPLY(tmp10
+ tmp12
, FIX(0.613604268)); /* c5 */
397 tmp2
+= tmp3
+ MULTIPLY(tmp12
, FIX(1.870828693)); /* c3+c1-c5 */
399 dataptr
[1] = (DCTELEM
) DESCALE(tmp0
, CONST_BITS
-PASS1_BITS
);
400 dataptr
[3] = (DCTELEM
) DESCALE(tmp1
, CONST_BITS
-PASS1_BITS
);
401 dataptr
[5] = (DCTELEM
) DESCALE(tmp2
, CONST_BITS
-PASS1_BITS
);
403 dataptr
+= DCTSIZE
; /* advance pointer to next row */
406 /* Pass 2: process columns.
407 * We remove the PASS1_BITS scaling, but leave the results scaled up
408 * by an overall factor of 8.
409 * We must also scale the output by (8/7)**2 = 64/49, which we fold
410 * into the constant multipliers:
411 * cK now represents sqrt(2) * cos(K*pi/14) * 64/49.
415 for (ctr
= 0; ctr
< 7; ctr
++) {
418 tmp0
= dataptr
[DCTSIZE
*0] + dataptr
[DCTSIZE
*6];
419 tmp1
= dataptr
[DCTSIZE
*1] + dataptr
[DCTSIZE
*5];
420 tmp2
= dataptr
[DCTSIZE
*2] + dataptr
[DCTSIZE
*4];
421 tmp3
= dataptr
[DCTSIZE
*3];
423 tmp10
= dataptr
[DCTSIZE
*0] - dataptr
[DCTSIZE
*6];
424 tmp11
= dataptr
[DCTSIZE
*1] - dataptr
[DCTSIZE
*5];
425 tmp12
= dataptr
[DCTSIZE
*2] - dataptr
[DCTSIZE
*4];
428 dataptr
[DCTSIZE
*0] = (DCTELEM
)
429 DESCALE(MULTIPLY(z1
+ tmp1
+ tmp3
, FIX(1.306122449)), /* 64/49 */
430 CONST_BITS
+PASS1_BITS
);
434 z1
= MULTIPLY(z1
, FIX(0.461784020)); /* (c2+c6-c4)/2 */
435 z2
= MULTIPLY(tmp0
- tmp2
, FIX(1.202428084)); /* (c2+c4-c6)/2 */
436 z3
= MULTIPLY(tmp1
- tmp2
, FIX(0.411026446)); /* c6 */
437 dataptr
[DCTSIZE
*2] = (DCTELEM
) DESCALE(z1
+ z2
+ z3
, CONST_BITS
+PASS1_BITS
);
439 z2
= MULTIPLY(tmp0
- tmp1
, FIX(1.151670509)); /* c4 */
440 dataptr
[DCTSIZE
*4] = (DCTELEM
)
441 DESCALE(z2
+ z3
- MULTIPLY(tmp1
- tmp3
, FIX(0.923568041)), /* c2+c6-c4 */
442 CONST_BITS
+PASS1_BITS
);
443 dataptr
[DCTSIZE
*6] = (DCTELEM
) DESCALE(z1
+ z2
, CONST_BITS
+PASS1_BITS
);
447 tmp1
= MULTIPLY(tmp10
+ tmp11
, FIX(1.221765677)); /* (c3+c1-c5)/2 */
448 tmp2
= MULTIPLY(tmp10
- tmp11
, FIX(0.222383464)); /* (c3+c5-c1)/2 */
451 tmp2
= MULTIPLY(tmp11
+ tmp12
, - FIX(1.800824523)); /* -c1 */
453 tmp3
= MULTIPLY(tmp10
+ tmp12
, FIX(0.801442310)); /* c5 */
455 tmp2
+= tmp3
+ MULTIPLY(tmp12
, FIX(2.443531355)); /* c3+c1-c5 */
457 dataptr
[DCTSIZE
*1] = (DCTELEM
) DESCALE(tmp0
, CONST_BITS
+PASS1_BITS
);
458 dataptr
[DCTSIZE
*3] = (DCTELEM
) DESCALE(tmp1
, CONST_BITS
+PASS1_BITS
);
459 dataptr
[DCTSIZE
*5] = (DCTELEM
) DESCALE(tmp2
, CONST_BITS
+PASS1_BITS
);
461 dataptr
++; /* advance pointer to next column */
467 * Perform the forward DCT on a 6x6 sample block.
471 jpeg_fdct_6x6 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
473 INT32 tmp0
, tmp1
, tmp2
;
474 INT32 tmp10
, tmp11
, tmp12
;
480 /* Pre-zero output coefficient block. */
481 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
483 /* Pass 1: process rows.
484 * Note results are scaled up by sqrt(8) compared to a true DCT;
485 * furthermore, we scale the results by 2**PASS1_BITS.
486 * cK represents sqrt(2) * cos(K*pi/12).
490 for (ctr
= 0; ctr
< 6; ctr
++) {
491 elemptr
= sample_data
[ctr
] + start_col
;
495 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[5]);
496 tmp11
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[4]);
497 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[3]);
502 tmp0
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[5]);
503 tmp1
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[4]);
504 tmp2
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[3]);
506 /* Apply unsigned->signed conversion */
507 dataptr
[0] = (DCTELEM
)
508 ((tmp10
+ tmp11
- 6 * CENTERJSAMPLE
) << PASS1_BITS
);
509 dataptr
[2] = (DCTELEM
)
510 DESCALE(MULTIPLY(tmp12
, FIX(1.224744871)), /* c2 */
511 CONST_BITS
-PASS1_BITS
);
512 dataptr
[4] = (DCTELEM
)
513 DESCALE(MULTIPLY(tmp10
- tmp11
- tmp11
, FIX(0.707106781)), /* c4 */
514 CONST_BITS
-PASS1_BITS
);
518 tmp10
= DESCALE(MULTIPLY(tmp0
+ tmp2
, FIX(0.366025404)), /* c5 */
519 CONST_BITS
-PASS1_BITS
);
521 dataptr
[1] = (DCTELEM
) (tmp10
+ ((tmp0
+ tmp1
) << PASS1_BITS
));
522 dataptr
[3] = (DCTELEM
) ((tmp0
- tmp1
- tmp2
) << PASS1_BITS
);
523 dataptr
[5] = (DCTELEM
) (tmp10
+ ((tmp2
- tmp1
) << PASS1_BITS
));
525 dataptr
+= DCTSIZE
; /* advance pointer to next row */
528 /* Pass 2: process columns.
529 * We remove the PASS1_BITS scaling, but leave the results scaled up
530 * by an overall factor of 8.
531 * We must also scale the output by (8/6)**2 = 16/9, which we fold
532 * into the constant multipliers:
533 * cK now represents sqrt(2) * cos(K*pi/12) * 16/9.
537 for (ctr
= 0; ctr
< 6; ctr
++) {
540 tmp0
= dataptr
[DCTSIZE
*0] + dataptr
[DCTSIZE
*5];
541 tmp11
= dataptr
[DCTSIZE
*1] + dataptr
[DCTSIZE
*4];
542 tmp2
= dataptr
[DCTSIZE
*2] + dataptr
[DCTSIZE
*3];
547 tmp0
= dataptr
[DCTSIZE
*0] - dataptr
[DCTSIZE
*5];
548 tmp1
= dataptr
[DCTSIZE
*1] - dataptr
[DCTSIZE
*4];
549 tmp2
= dataptr
[DCTSIZE
*2] - dataptr
[DCTSIZE
*3];
551 dataptr
[DCTSIZE
*0] = (DCTELEM
)
552 DESCALE(MULTIPLY(tmp10
+ tmp11
, FIX(1.777777778)), /* 16/9 */
553 CONST_BITS
+PASS1_BITS
);
554 dataptr
[DCTSIZE
*2] = (DCTELEM
)
555 DESCALE(MULTIPLY(tmp12
, FIX(2.177324216)), /* c2 */
556 CONST_BITS
+PASS1_BITS
);
557 dataptr
[DCTSIZE
*4] = (DCTELEM
)
558 DESCALE(MULTIPLY(tmp10
- tmp11
- tmp11
, FIX(1.257078722)), /* c4 */
559 CONST_BITS
+PASS1_BITS
);
563 tmp10
= MULTIPLY(tmp0
+ tmp2
, FIX(0.650711829)); /* c5 */
565 dataptr
[DCTSIZE
*1] = (DCTELEM
)
566 DESCALE(tmp10
+ MULTIPLY(tmp0
+ tmp1
, FIX(1.777777778)), /* 16/9 */
567 CONST_BITS
+PASS1_BITS
);
568 dataptr
[DCTSIZE
*3] = (DCTELEM
)
569 DESCALE(MULTIPLY(tmp0
- tmp1
- tmp2
, FIX(1.777777778)), /* 16/9 */
570 CONST_BITS
+PASS1_BITS
);
571 dataptr
[DCTSIZE
*5] = (DCTELEM
)
572 DESCALE(tmp10
+ MULTIPLY(tmp2
- tmp1
, FIX(1.777777778)), /* 16/9 */
573 CONST_BITS
+PASS1_BITS
);
575 dataptr
++; /* advance pointer to next column */
581 * Perform the forward DCT on a 5x5 sample block.
585 jpeg_fdct_5x5 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
587 INT32 tmp0
, tmp1
, tmp2
;
594 /* Pre-zero output coefficient block. */
595 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
597 /* Pass 1: process rows.
598 * Note results are scaled up by sqrt(8) compared to a true DCT;
599 * furthermore, we scale the results by 2**PASS1_BITS.
600 * We scale the results further by 2 as part of output adaption
601 * scaling for different DCT size.
602 * cK represents sqrt(2) * cos(K*pi/10).
606 for (ctr
= 0; ctr
< 5; ctr
++) {
607 elemptr
= sample_data
[ctr
] + start_col
;
611 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[4]);
612 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[3]);
613 tmp2
= GETJSAMPLE(elemptr
[2]);
618 tmp0
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[4]);
619 tmp1
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[3]);
621 /* Apply unsigned->signed conversion */
622 dataptr
[0] = (DCTELEM
)
623 ((tmp10
+ tmp2
- 5 * CENTERJSAMPLE
) << (PASS1_BITS
+1));
624 tmp11
= MULTIPLY(tmp11
, FIX(0.790569415)); /* (c2+c4)/2 */
626 tmp10
= MULTIPLY(tmp10
, FIX(0.353553391)); /* (c2-c4)/2 */
627 dataptr
[2] = (DCTELEM
) DESCALE(tmp11
+ tmp10
, CONST_BITS
-PASS1_BITS
-1);
628 dataptr
[4] = (DCTELEM
) DESCALE(tmp11
- tmp10
, CONST_BITS
-PASS1_BITS
-1);
632 tmp10
= MULTIPLY(tmp0
+ tmp1
, FIX(0.831253876)); /* c3 */
634 dataptr
[1] = (DCTELEM
)
635 DESCALE(tmp10
+ MULTIPLY(tmp0
, FIX(0.513743148)), /* c1-c3 */
636 CONST_BITS
-PASS1_BITS
-1);
637 dataptr
[3] = (DCTELEM
)
638 DESCALE(tmp10
- MULTIPLY(tmp1
, FIX(2.176250899)), /* c1+c3 */
639 CONST_BITS
-PASS1_BITS
-1);
641 dataptr
+= DCTSIZE
; /* advance pointer to next row */
644 /* Pass 2: process columns.
645 * We remove the PASS1_BITS scaling, but leave the results scaled up
646 * by an overall factor of 8.
647 * We must also scale the output by (8/5)**2 = 64/25, which we partially
648 * fold into the constant multipliers (other part was done in pass 1):
649 * cK now represents sqrt(2) * cos(K*pi/10) * 32/25.
653 for (ctr
= 0; ctr
< 5; ctr
++) {
656 tmp0
= dataptr
[DCTSIZE
*0] + dataptr
[DCTSIZE
*4];
657 tmp1
= dataptr
[DCTSIZE
*1] + dataptr
[DCTSIZE
*3];
658 tmp2
= dataptr
[DCTSIZE
*2];
663 tmp0
= dataptr
[DCTSIZE
*0] - dataptr
[DCTSIZE
*4];
664 tmp1
= dataptr
[DCTSIZE
*1] - dataptr
[DCTSIZE
*3];
666 dataptr
[DCTSIZE
*0] = (DCTELEM
)
667 DESCALE(MULTIPLY(tmp10
+ tmp2
, FIX(1.28)), /* 32/25 */
668 CONST_BITS
+PASS1_BITS
);
669 tmp11
= MULTIPLY(tmp11
, FIX(1.011928851)); /* (c2+c4)/2 */
671 tmp10
= MULTIPLY(tmp10
, FIX(0.452548340)); /* (c2-c4)/2 */
672 dataptr
[DCTSIZE
*2] = (DCTELEM
) DESCALE(tmp11
+ tmp10
, CONST_BITS
+PASS1_BITS
);
673 dataptr
[DCTSIZE
*4] = (DCTELEM
) DESCALE(tmp11
- tmp10
, CONST_BITS
+PASS1_BITS
);
677 tmp10
= MULTIPLY(tmp0
+ tmp1
, FIX(1.064004961)); /* c3 */
679 dataptr
[DCTSIZE
*1] = (DCTELEM
)
680 DESCALE(tmp10
+ MULTIPLY(tmp0
, FIX(0.657591230)), /* c1-c3 */
681 CONST_BITS
+PASS1_BITS
);
682 dataptr
[DCTSIZE
*3] = (DCTELEM
)
683 DESCALE(tmp10
- MULTIPLY(tmp1
, FIX(2.785601151)), /* c1+c3 */
684 CONST_BITS
+PASS1_BITS
);
686 dataptr
++; /* advance pointer to next column */
692 * Perform the forward DCT on a 4x4 sample block.
696 jpeg_fdct_4x4 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
705 /* Pre-zero output coefficient block. */
706 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
708 /* Pass 1: process rows.
709 * Note results are scaled up by sqrt(8) compared to a true DCT;
710 * furthermore, we scale the results by 2**PASS1_BITS.
711 * We must also scale the output by (8/4)**2 = 2**2, which we add here.
712 * cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point FDCT].
716 for (ctr
= 0; ctr
< 4; ctr
++) {
717 elemptr
= sample_data
[ctr
] + start_col
;
721 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[3]);
722 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[2]);
724 tmp10
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[3]);
725 tmp11
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[2]);
727 /* Apply unsigned->signed conversion */
728 dataptr
[0] = (DCTELEM
)
729 ((tmp0
+ tmp1
- 4 * CENTERJSAMPLE
) << (PASS1_BITS
+2));
730 dataptr
[2] = (DCTELEM
) ((tmp0
- tmp1
) << (PASS1_BITS
+2));
734 tmp0
= MULTIPLY(tmp10
+ tmp11
, FIX_0_541196100
); /* c6 */
735 /* Add fudge factor here for final descale. */
736 tmp0
+= ONE
<< (CONST_BITS
-PASS1_BITS
-3);
738 dataptr
[1] = (DCTELEM
)
739 RIGHT_SHIFT(tmp0
+ MULTIPLY(tmp10
, FIX_0_765366865
), /* c2-c6 */
740 CONST_BITS
-PASS1_BITS
-2);
741 dataptr
[3] = (DCTELEM
)
742 RIGHT_SHIFT(tmp0
- MULTIPLY(tmp11
, FIX_1_847759065
), /* c2+c6 */
743 CONST_BITS
-PASS1_BITS
-2);
745 dataptr
+= DCTSIZE
; /* advance pointer to next row */
748 /* Pass 2: process columns.
749 * We remove the PASS1_BITS scaling, but leave the results scaled up
750 * by an overall factor of 8.
751 * cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point FDCT].
755 for (ctr
= 0; ctr
< 4; ctr
++) {
758 /* Add fudge factor here for final descale. */
759 tmp0
= dataptr
[DCTSIZE
*0] + dataptr
[DCTSIZE
*3] + (ONE
<< (PASS1_BITS
-1));
760 tmp1
= dataptr
[DCTSIZE
*1] + dataptr
[DCTSIZE
*2];
762 tmp10
= dataptr
[DCTSIZE
*0] - dataptr
[DCTSIZE
*3];
763 tmp11
= dataptr
[DCTSIZE
*1] - dataptr
[DCTSIZE
*2];
765 dataptr
[DCTSIZE
*0] = (DCTELEM
) RIGHT_SHIFT(tmp0
+ tmp1
, PASS1_BITS
);
766 dataptr
[DCTSIZE
*2] = (DCTELEM
) RIGHT_SHIFT(tmp0
- tmp1
, PASS1_BITS
);
770 tmp0
= MULTIPLY(tmp10
+ tmp11
, FIX_0_541196100
); /* c6 */
771 /* Add fudge factor here for final descale. */
772 tmp0
+= ONE
<< (CONST_BITS
+PASS1_BITS
-1);
774 dataptr
[DCTSIZE
*1] = (DCTELEM
)
775 RIGHT_SHIFT(tmp0
+ MULTIPLY(tmp10
, FIX_0_765366865
), /* c2-c6 */
776 CONST_BITS
+PASS1_BITS
);
777 dataptr
[DCTSIZE
*3] = (DCTELEM
)
778 RIGHT_SHIFT(tmp0
- MULTIPLY(tmp11
, FIX_1_847759065
), /* c2+c6 */
779 CONST_BITS
+PASS1_BITS
);
781 dataptr
++; /* advance pointer to next column */
787 * Perform the forward DCT on a 3x3 sample block.
791 jpeg_fdct_3x3 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
793 INT32 tmp0
, tmp1
, tmp2
;
799 /* Pre-zero output coefficient block. */
800 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
802 /* Pass 1: process rows.
803 * Note results are scaled up by sqrt(8) compared to a true DCT;
804 * furthermore, we scale the results by 2**PASS1_BITS.
805 * We scale the results further by 2**2 as part of output adaption
806 * scaling for different DCT size.
807 * cK represents sqrt(2) * cos(K*pi/6).
811 for (ctr
= 0; ctr
< 3; ctr
++) {
812 elemptr
= sample_data
[ctr
] + start_col
;
816 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[2]);
817 tmp1
= GETJSAMPLE(elemptr
[1]);
819 tmp2
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[2]);
821 /* Apply unsigned->signed conversion */
822 dataptr
[0] = (DCTELEM
)
823 ((tmp0
+ tmp1
- 3 * CENTERJSAMPLE
) << (PASS1_BITS
+2));
824 dataptr
[2] = (DCTELEM
)
825 DESCALE(MULTIPLY(tmp0
- tmp1
- tmp1
, FIX(0.707106781)), /* c2 */
826 CONST_BITS
-PASS1_BITS
-2);
830 dataptr
[1] = (DCTELEM
)
831 DESCALE(MULTIPLY(tmp2
, FIX(1.224744871)), /* c1 */
832 CONST_BITS
-PASS1_BITS
-2);
834 dataptr
+= DCTSIZE
; /* advance pointer to next row */
837 /* Pass 2: process columns.
838 * We remove the PASS1_BITS scaling, but leave the results scaled up
839 * by an overall factor of 8.
840 * We must also scale the output by (8/3)**2 = 64/9, which we partially
841 * fold into the constant multipliers (other part was done in pass 1):
842 * cK now represents sqrt(2) * cos(K*pi/6) * 16/9.
846 for (ctr
= 0; ctr
< 3; ctr
++) {
849 tmp0
= dataptr
[DCTSIZE
*0] + dataptr
[DCTSIZE
*2];
850 tmp1
= dataptr
[DCTSIZE
*1];
852 tmp2
= dataptr
[DCTSIZE
*0] - dataptr
[DCTSIZE
*2];
854 dataptr
[DCTSIZE
*0] = (DCTELEM
)
855 DESCALE(MULTIPLY(tmp0
+ tmp1
, FIX(1.777777778)), /* 16/9 */
856 CONST_BITS
+PASS1_BITS
);
857 dataptr
[DCTSIZE
*2] = (DCTELEM
)
858 DESCALE(MULTIPLY(tmp0
- tmp1
- tmp1
, FIX(1.257078722)), /* c2 */
859 CONST_BITS
+PASS1_BITS
);
863 dataptr
[DCTSIZE
*1] = (DCTELEM
)
864 DESCALE(MULTIPLY(tmp2
, FIX(2.177324216)), /* c1 */
865 CONST_BITS
+PASS1_BITS
);
867 dataptr
++; /* advance pointer to next column */
873 * Perform the forward DCT on a 2x2 sample block.
877 jpeg_fdct_2x2 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
879 INT32 tmp0
, tmp1
, tmp2
, tmp3
;
882 /* Pre-zero output coefficient block. */
883 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
885 /* Pass 1: process rows.
886 * Note results are scaled up by sqrt(8) compared to a true DCT.
890 elemptr
= sample_data
[0] + start_col
;
892 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[1]);
893 tmp1
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[1]);
896 elemptr
= sample_data
[1] + start_col
;
898 tmp2
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[1]);
899 tmp3
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[1]);
901 /* Pass 2: process columns.
902 * We leave the results scaled up by an overall factor of 8.
903 * We must also scale the output by (8/2)**2 = 2**4.
907 /* Apply unsigned->signed conversion */
908 data
[DCTSIZE
*0] = (DCTELEM
) ((tmp0
+ tmp2
- 4 * CENTERJSAMPLE
) << 4);
909 data
[DCTSIZE
*1] = (DCTELEM
) ((tmp0
- tmp2
) << 4);
912 data
[DCTSIZE
*0+1] = (DCTELEM
) ((tmp1
+ tmp3
) << 4);
913 data
[DCTSIZE
*1+1] = (DCTELEM
) ((tmp1
- tmp3
) << 4);
918 * Perform the forward DCT on a 1x1 sample block.
922 jpeg_fdct_1x1 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
924 /* Pre-zero output coefficient block. */
925 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
927 /* We leave the result scaled up by an overall factor of 8. */
928 /* We must also scale the output by (8/1)**2 = 2**6. */
929 /* Apply unsigned->signed conversion */
931 ((GETJSAMPLE(sample_data
[0][start_col
]) - CENTERJSAMPLE
) << 6);
936 * Perform the forward DCT on a 9x9 sample block.
940 jpeg_fdct_9x9 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
942 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
;
943 INT32 tmp10
, tmp11
, tmp12
, tmp13
;
945 DCTELEM workspace
[8];
952 /* Pass 1: process rows.
953 * Note results are scaled up by sqrt(8) compared to a true DCT;
954 * we scale the results further by 2 as part of output adaption
955 * scaling for different DCT size.
956 * cK represents sqrt(2) * cos(K*pi/18).
962 elemptr
= sample_data
[ctr
] + start_col
;
966 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[8]);
967 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[7]);
968 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[6]);
969 tmp3
= GETJSAMPLE(elemptr
[3]) + GETJSAMPLE(elemptr
[5]);
970 tmp4
= GETJSAMPLE(elemptr
[4]);
972 tmp10
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[8]);
973 tmp11
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[7]);
974 tmp12
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[6]);
975 tmp13
= GETJSAMPLE(elemptr
[3]) - GETJSAMPLE(elemptr
[5]);
977 z1
= tmp0
+ tmp2
+ tmp3
;
979 /* Apply unsigned->signed conversion */
980 dataptr
[0] = (DCTELEM
) ((z1
+ z2
- 9 * CENTERJSAMPLE
) << 1);
981 dataptr
[6] = (DCTELEM
)
982 DESCALE(MULTIPLY(z1
- z2
- z2
, FIX(0.707106781)), /* c6 */
984 z1
= MULTIPLY(tmp0
- tmp2
, FIX(1.328926049)); /* c2 */
985 z2
= MULTIPLY(tmp1
- tmp4
- tmp4
, FIX(0.707106781)); /* c6 */
986 dataptr
[2] = (DCTELEM
)
987 DESCALE(MULTIPLY(tmp2
- tmp3
, FIX(1.083350441)) /* c4 */
988 + z1
+ z2
, CONST_BITS
-1);
989 dataptr
[4] = (DCTELEM
)
990 DESCALE(MULTIPLY(tmp3
- tmp0
, FIX(0.245575608)) /* c8 */
991 + z1
- z2
, CONST_BITS
-1);
995 dataptr
[3] = (DCTELEM
)
996 DESCALE(MULTIPLY(tmp10
- tmp12
- tmp13
, FIX(1.224744871)), /* c3 */
999 tmp11
= MULTIPLY(tmp11
, FIX(1.224744871)); /* c3 */
1000 tmp0
= MULTIPLY(tmp10
+ tmp12
, FIX(0.909038955)); /* c5 */
1001 tmp1
= MULTIPLY(tmp10
+ tmp13
, FIX(0.483689525)); /* c7 */
1003 dataptr
[1] = (DCTELEM
) DESCALE(tmp11
+ tmp0
+ tmp1
, CONST_BITS
-1);
1005 tmp2
= MULTIPLY(tmp12
- tmp13
, FIX(1.392728481)); /* c1 */
1007 dataptr
[5] = (DCTELEM
) DESCALE(tmp0
- tmp11
- tmp2
, CONST_BITS
-1);
1008 dataptr
[7] = (DCTELEM
) DESCALE(tmp1
- tmp11
+ tmp2
, CONST_BITS
-1);
1012 if (ctr
!= DCTSIZE
) {
1015 dataptr
+= DCTSIZE
; /* advance pointer to next row */
1017 dataptr
= workspace
; /* switch pointer to extended workspace */
1020 /* Pass 2: process columns.
1021 * We leave the results scaled up by an overall factor of 8.
1022 * We must also scale the output by (8/9)**2 = 64/81, which we partially
1023 * fold into the constant multipliers and final/initial shifting:
1024 * cK now represents sqrt(2) * cos(K*pi/18) * 128/81.
1029 for (ctr
= DCTSIZE
-1; ctr
>= 0; ctr
--) {
1032 tmp0
= dataptr
[DCTSIZE
*0] + wsptr
[DCTSIZE
*0];
1033 tmp1
= dataptr
[DCTSIZE
*1] + dataptr
[DCTSIZE
*7];
1034 tmp2
= dataptr
[DCTSIZE
*2] + dataptr
[DCTSIZE
*6];
1035 tmp3
= dataptr
[DCTSIZE
*3] + dataptr
[DCTSIZE
*5];
1036 tmp4
= dataptr
[DCTSIZE
*4];
1038 tmp10
= dataptr
[DCTSIZE
*0] - wsptr
[DCTSIZE
*0];
1039 tmp11
= dataptr
[DCTSIZE
*1] - dataptr
[DCTSIZE
*7];
1040 tmp12
= dataptr
[DCTSIZE
*2] - dataptr
[DCTSIZE
*6];
1041 tmp13
= dataptr
[DCTSIZE
*3] - dataptr
[DCTSIZE
*5];
1043 z1
= tmp0
+ tmp2
+ tmp3
;
1045 dataptr
[DCTSIZE
*0] = (DCTELEM
)
1046 DESCALE(MULTIPLY(z1
+ z2
, FIX(1.580246914)), /* 128/81 */
1048 dataptr
[DCTSIZE
*6] = (DCTELEM
)
1049 DESCALE(MULTIPLY(z1
- z2
- z2
, FIX(1.117403309)), /* c6 */
1051 z1
= MULTIPLY(tmp0
- tmp2
, FIX(2.100031287)); /* c2 */
1052 z2
= MULTIPLY(tmp1
- tmp4
- tmp4
, FIX(1.117403309)); /* c6 */
1053 dataptr
[DCTSIZE
*2] = (DCTELEM
)
1054 DESCALE(MULTIPLY(tmp2
- tmp3
, FIX(1.711961190)) /* c4 */
1055 + z1
+ z2
, CONST_BITS
+2);
1056 dataptr
[DCTSIZE
*4] = (DCTELEM
)
1057 DESCALE(MULTIPLY(tmp3
- tmp0
, FIX(0.388070096)) /* c8 */
1058 + z1
- z2
, CONST_BITS
+2);
1062 dataptr
[DCTSIZE
*3] = (DCTELEM
)
1063 DESCALE(MULTIPLY(tmp10
- tmp12
- tmp13
, FIX(1.935399303)), /* c3 */
1066 tmp11
= MULTIPLY(tmp11
, FIX(1.935399303)); /* c3 */
1067 tmp0
= MULTIPLY(tmp10
+ tmp12
, FIX(1.436506004)); /* c5 */
1068 tmp1
= MULTIPLY(tmp10
+ tmp13
, FIX(0.764348879)); /* c7 */
1070 dataptr
[DCTSIZE
*1] = (DCTELEM
)
1071 DESCALE(tmp11
+ tmp0
+ tmp1
, CONST_BITS
+2);
1073 tmp2
= MULTIPLY(tmp12
- tmp13
, FIX(2.200854883)); /* c1 */
1075 dataptr
[DCTSIZE
*5] = (DCTELEM
)
1076 DESCALE(tmp0
- tmp11
- tmp2
, CONST_BITS
+2);
1077 dataptr
[DCTSIZE
*7] = (DCTELEM
)
1078 DESCALE(tmp1
- tmp11
+ tmp2
, CONST_BITS
+2);
1080 dataptr
++; /* advance pointer to next column */
1081 wsptr
++; /* advance pointer to next column */
1087 * Perform the forward DCT on a 10x10 sample block.
1091 jpeg_fdct_10x10 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
1093 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
;
1094 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
;
1095 DCTELEM workspace
[8*2];
1102 /* Pass 1: process rows.
1103 * Note results are scaled up by sqrt(8) compared to a true DCT;
1104 * we scale the results further by 2 as part of output adaption
1105 * scaling for different DCT size.
1106 * cK represents sqrt(2) * cos(K*pi/20).
1112 elemptr
= sample_data
[ctr
] + start_col
;
1116 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[9]);
1117 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[8]);
1118 tmp12
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[7]);
1119 tmp3
= GETJSAMPLE(elemptr
[3]) + GETJSAMPLE(elemptr
[6]);
1120 tmp4
= GETJSAMPLE(elemptr
[4]) + GETJSAMPLE(elemptr
[5]);
1122 tmp10
= tmp0
+ tmp4
;
1123 tmp13
= tmp0
- tmp4
;
1124 tmp11
= tmp1
+ tmp3
;
1125 tmp14
= tmp1
- tmp3
;
1127 tmp0
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[9]);
1128 tmp1
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[8]);
1129 tmp2
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[7]);
1130 tmp3
= GETJSAMPLE(elemptr
[3]) - GETJSAMPLE(elemptr
[6]);
1131 tmp4
= GETJSAMPLE(elemptr
[4]) - GETJSAMPLE(elemptr
[5]);
1133 /* Apply unsigned->signed conversion */
1134 dataptr
[0] = (DCTELEM
)
1135 ((tmp10
+ tmp11
+ tmp12
- 10 * CENTERJSAMPLE
) << 1);
1137 dataptr
[4] = (DCTELEM
)
1138 DESCALE(MULTIPLY(tmp10
- tmp12
, FIX(1.144122806)) - /* c4 */
1139 MULTIPLY(tmp11
- tmp12
, FIX(0.437016024)), /* c8 */
1141 tmp10
= MULTIPLY(tmp13
+ tmp14
, FIX(0.831253876)); /* c6 */
1142 dataptr
[2] = (DCTELEM
)
1143 DESCALE(tmp10
+ MULTIPLY(tmp13
, FIX(0.513743148)), /* c2-c6 */
1145 dataptr
[6] = (DCTELEM
)
1146 DESCALE(tmp10
- MULTIPLY(tmp14
, FIX(2.176250899)), /* c2+c6 */
1151 tmp10
= tmp0
+ tmp4
;
1152 tmp11
= tmp1
- tmp3
;
1153 dataptr
[5] = (DCTELEM
) ((tmp10
- tmp11
- tmp2
) << 1);
1154 tmp2
<<= CONST_BITS
;
1155 dataptr
[1] = (DCTELEM
)
1156 DESCALE(MULTIPLY(tmp0
, FIX(1.396802247)) + /* c1 */
1157 MULTIPLY(tmp1
, FIX(1.260073511)) + tmp2
+ /* c3 */
1158 MULTIPLY(tmp3
, FIX(0.642039522)) + /* c7 */
1159 MULTIPLY(tmp4
, FIX(0.221231742)), /* c9 */
1161 tmp12
= MULTIPLY(tmp0
- tmp4
, FIX(0.951056516)) - /* (c3+c7)/2 */
1162 MULTIPLY(tmp1
+ tmp3
, FIX(0.587785252)); /* (c1-c9)/2 */
1163 tmp13
= MULTIPLY(tmp10
+ tmp11
, FIX(0.309016994)) + /* (c3-c7)/2 */
1164 (tmp11
<< (CONST_BITS
- 1)) - tmp2
;
1165 dataptr
[3] = (DCTELEM
) DESCALE(tmp12
+ tmp13
, CONST_BITS
-1);
1166 dataptr
[7] = (DCTELEM
) DESCALE(tmp12
- tmp13
, CONST_BITS
-1);
1170 if (ctr
!= DCTSIZE
) {
1173 dataptr
+= DCTSIZE
; /* advance pointer to next row */
1175 dataptr
= workspace
; /* switch pointer to extended workspace */
1178 /* Pass 2: process columns.
1179 * We leave the results scaled up by an overall factor of 8.
1180 * We must also scale the output by (8/10)**2 = 16/25, which we partially
1181 * fold into the constant multipliers and final/initial shifting:
1182 * cK now represents sqrt(2) * cos(K*pi/20) * 32/25.
1187 for (ctr
= DCTSIZE
-1; ctr
>= 0; ctr
--) {
1190 tmp0
= dataptr
[DCTSIZE
*0] + wsptr
[DCTSIZE
*1];
1191 tmp1
= dataptr
[DCTSIZE
*1] + wsptr
[DCTSIZE
*0];
1192 tmp12
= dataptr
[DCTSIZE
*2] + dataptr
[DCTSIZE
*7];
1193 tmp3
= dataptr
[DCTSIZE
*3] + dataptr
[DCTSIZE
*6];
1194 tmp4
= dataptr
[DCTSIZE
*4] + dataptr
[DCTSIZE
*5];
1196 tmp10
= tmp0
+ tmp4
;
1197 tmp13
= tmp0
- tmp4
;
1198 tmp11
= tmp1
+ tmp3
;
1199 tmp14
= tmp1
- tmp3
;
1201 tmp0
= dataptr
[DCTSIZE
*0] - wsptr
[DCTSIZE
*1];
1202 tmp1
= dataptr
[DCTSIZE
*1] - wsptr
[DCTSIZE
*0];
1203 tmp2
= dataptr
[DCTSIZE
*2] - dataptr
[DCTSIZE
*7];
1204 tmp3
= dataptr
[DCTSIZE
*3] - dataptr
[DCTSIZE
*6];
1205 tmp4
= dataptr
[DCTSIZE
*4] - dataptr
[DCTSIZE
*5];
1207 dataptr
[DCTSIZE
*0] = (DCTELEM
)
1208 DESCALE(MULTIPLY(tmp10
+ tmp11
+ tmp12
, FIX(1.28)), /* 32/25 */
1211 dataptr
[DCTSIZE
*4] = (DCTELEM
)
1212 DESCALE(MULTIPLY(tmp10
- tmp12
, FIX(1.464477191)) - /* c4 */
1213 MULTIPLY(tmp11
- tmp12
, FIX(0.559380511)), /* c8 */
1215 tmp10
= MULTIPLY(tmp13
+ tmp14
, FIX(1.064004961)); /* c6 */
1216 dataptr
[DCTSIZE
*2] = (DCTELEM
)
1217 DESCALE(tmp10
+ MULTIPLY(tmp13
, FIX(0.657591230)), /* c2-c6 */
1219 dataptr
[DCTSIZE
*6] = (DCTELEM
)
1220 DESCALE(tmp10
- MULTIPLY(tmp14
, FIX(2.785601151)), /* c2+c6 */
1225 tmp10
= tmp0
+ tmp4
;
1226 tmp11
= tmp1
- tmp3
;
1227 dataptr
[DCTSIZE
*5] = (DCTELEM
)
1228 DESCALE(MULTIPLY(tmp10
- tmp11
- tmp2
, FIX(1.28)), /* 32/25 */
1230 tmp2
= MULTIPLY(tmp2
, FIX(1.28)); /* 32/25 */
1231 dataptr
[DCTSIZE
*1] = (DCTELEM
)
1232 DESCALE(MULTIPLY(tmp0
, FIX(1.787906876)) + /* c1 */
1233 MULTIPLY(tmp1
, FIX(1.612894094)) + tmp2
+ /* c3 */
1234 MULTIPLY(tmp3
, FIX(0.821810588)) + /* c7 */
1235 MULTIPLY(tmp4
, FIX(0.283176630)), /* c9 */
1237 tmp12
= MULTIPLY(tmp0
- tmp4
, FIX(1.217352341)) - /* (c3+c7)/2 */
1238 MULTIPLY(tmp1
+ tmp3
, FIX(0.752365123)); /* (c1-c9)/2 */
1239 tmp13
= MULTIPLY(tmp10
+ tmp11
, FIX(0.395541753)) + /* (c3-c7)/2 */
1240 MULTIPLY(tmp11
, FIX(0.64)) - tmp2
; /* 16/25 */
1241 dataptr
[DCTSIZE
*3] = (DCTELEM
) DESCALE(tmp12
+ tmp13
, CONST_BITS
+2);
1242 dataptr
[DCTSIZE
*7] = (DCTELEM
) DESCALE(tmp12
- tmp13
, CONST_BITS
+2);
1244 dataptr
++; /* advance pointer to next column */
1245 wsptr
++; /* advance pointer to next column */
1251 * Perform the forward DCT on an 11x11 sample block.
1255 jpeg_fdct_11x11 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
1257 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
, tmp5
;
1258 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
;
1260 DCTELEM workspace
[8*3];
1267 /* Pass 1: process rows.
1268 * Note results are scaled up by sqrt(8) compared to a true DCT;
1269 * we scale the results further by 2 as part of output adaption
1270 * scaling for different DCT size.
1271 * cK represents sqrt(2) * cos(K*pi/22).
1277 elemptr
= sample_data
[ctr
] + start_col
;
1281 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[10]);
1282 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[9]);
1283 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[8]);
1284 tmp3
= GETJSAMPLE(elemptr
[3]) + GETJSAMPLE(elemptr
[7]);
1285 tmp4
= GETJSAMPLE(elemptr
[4]) + GETJSAMPLE(elemptr
[6]);
1286 tmp5
= GETJSAMPLE(elemptr
[5]);
1288 tmp10
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[10]);
1289 tmp11
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[9]);
1290 tmp12
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[8]);
1291 tmp13
= GETJSAMPLE(elemptr
[3]) - GETJSAMPLE(elemptr
[7]);
1292 tmp14
= GETJSAMPLE(elemptr
[4]) - GETJSAMPLE(elemptr
[6]);
1294 /* Apply unsigned->signed conversion */
1295 dataptr
[0] = (DCTELEM
)
1296 ((tmp0
+ tmp1
+ tmp2
+ tmp3
+ tmp4
+ tmp5
- 11 * CENTERJSAMPLE
) << 1);
1303 z1
= MULTIPLY(tmp0
+ tmp3
, FIX(1.356927976)) + /* c2 */
1304 MULTIPLY(tmp2
+ tmp4
, FIX(0.201263574)); /* c10 */
1305 z2
= MULTIPLY(tmp1
- tmp3
, FIX(0.926112931)); /* c6 */
1306 z3
= MULTIPLY(tmp0
- tmp1
, FIX(1.189712156)); /* c4 */
1307 dataptr
[2] = (DCTELEM
)
1308 DESCALE(z1
+ z2
- MULTIPLY(tmp3
, FIX(1.018300590)) /* c2+c8-c6 */
1309 - MULTIPLY(tmp4
, FIX(1.390975730)), /* c4+c10 */
1311 dataptr
[4] = (DCTELEM
)
1312 DESCALE(z2
+ z3
+ MULTIPLY(tmp1
, FIX(0.062335650)) /* c4-c6-c10 */
1313 - MULTIPLY(tmp2
, FIX(1.356927976)) /* c2 */
1314 + MULTIPLY(tmp4
, FIX(0.587485545)), /* c8 */
1316 dataptr
[6] = (DCTELEM
)
1317 DESCALE(z1
+ z3
- MULTIPLY(tmp0
, FIX(1.620527200)) /* c2+c4-c6 */
1318 - MULTIPLY(tmp2
, FIX(0.788749120)), /* c8+c10 */
1323 tmp1
= MULTIPLY(tmp10
+ tmp11
, FIX(1.286413905)); /* c3 */
1324 tmp2
= MULTIPLY(tmp10
+ tmp12
, FIX(1.068791298)); /* c5 */
1325 tmp3
= MULTIPLY(tmp10
+ tmp13
, FIX(0.764581576)); /* c7 */
1326 tmp0
= tmp1
+ tmp2
+ tmp3
- MULTIPLY(tmp10
, FIX(1.719967871)) /* c7+c5+c3-c1 */
1327 + MULTIPLY(tmp14
, FIX(0.398430003)); /* c9 */
1328 tmp4
= MULTIPLY(tmp11
+ tmp12
, - FIX(0.764581576)); /* -c7 */
1329 tmp5
= MULTIPLY(tmp11
+ tmp13
, - FIX(1.399818907)); /* -c1 */
1330 tmp1
+= tmp4
+ tmp5
+ MULTIPLY(tmp11
, FIX(1.276416582)) /* c9+c7+c1-c3 */
1331 - MULTIPLY(tmp14
, FIX(1.068791298)); /* c5 */
1332 tmp10
= MULTIPLY(tmp12
+ tmp13
, FIX(0.398430003)); /* c9 */
1333 tmp2
+= tmp4
+ tmp10
- MULTIPLY(tmp12
, FIX(1.989053629)) /* c9+c5+c3-c7 */
1334 + MULTIPLY(tmp14
, FIX(1.399818907)); /* c1 */
1335 tmp3
+= tmp5
+ tmp10
+ MULTIPLY(tmp13
, FIX(1.305598626)) /* c1+c5-c9-c7 */
1336 - MULTIPLY(tmp14
, FIX(1.286413905)); /* c3 */
1338 dataptr
[1] = (DCTELEM
) DESCALE(tmp0
, CONST_BITS
-1);
1339 dataptr
[3] = (DCTELEM
) DESCALE(tmp1
, CONST_BITS
-1);
1340 dataptr
[5] = (DCTELEM
) DESCALE(tmp2
, CONST_BITS
-1);
1341 dataptr
[7] = (DCTELEM
) DESCALE(tmp3
, CONST_BITS
-1);
1345 if (ctr
!= DCTSIZE
) {
1348 dataptr
+= DCTSIZE
; /* advance pointer to next row */
1350 dataptr
= workspace
; /* switch pointer to extended workspace */
1353 /* Pass 2: process columns.
1354 * We leave the results scaled up by an overall factor of 8.
1355 * We must also scale the output by (8/11)**2 = 64/121, which we partially
1356 * fold into the constant multipliers and final/initial shifting:
1357 * cK now represents sqrt(2) * cos(K*pi/22) * 128/121.
1362 for (ctr
= DCTSIZE
-1; ctr
>= 0; ctr
--) {
1365 tmp0
= dataptr
[DCTSIZE
*0] + wsptr
[DCTSIZE
*2];
1366 tmp1
= dataptr
[DCTSIZE
*1] + wsptr
[DCTSIZE
*1];
1367 tmp2
= dataptr
[DCTSIZE
*2] + wsptr
[DCTSIZE
*0];
1368 tmp3
= dataptr
[DCTSIZE
*3] + dataptr
[DCTSIZE
*7];
1369 tmp4
= dataptr
[DCTSIZE
*4] + dataptr
[DCTSIZE
*6];
1370 tmp5
= dataptr
[DCTSIZE
*5];
1372 tmp10
= dataptr
[DCTSIZE
*0] - wsptr
[DCTSIZE
*2];
1373 tmp11
= dataptr
[DCTSIZE
*1] - wsptr
[DCTSIZE
*1];
1374 tmp12
= dataptr
[DCTSIZE
*2] - wsptr
[DCTSIZE
*0];
1375 tmp13
= dataptr
[DCTSIZE
*3] - dataptr
[DCTSIZE
*7];
1376 tmp14
= dataptr
[DCTSIZE
*4] - dataptr
[DCTSIZE
*6];
1378 dataptr
[DCTSIZE
*0] = (DCTELEM
)
1379 DESCALE(MULTIPLY(tmp0
+ tmp1
+ tmp2
+ tmp3
+ tmp4
+ tmp5
,
1380 FIX(1.057851240)), /* 128/121 */
1388 z1
= MULTIPLY(tmp0
+ tmp3
, FIX(1.435427942)) + /* c2 */
1389 MULTIPLY(tmp2
+ tmp4
, FIX(0.212906922)); /* c10 */
1390 z2
= MULTIPLY(tmp1
- tmp3
, FIX(0.979689713)); /* c6 */
1391 z3
= MULTIPLY(tmp0
- tmp1
, FIX(1.258538479)); /* c4 */
1392 dataptr
[DCTSIZE
*2] = (DCTELEM
)
1393 DESCALE(z1
+ z2
- MULTIPLY(tmp3
, FIX(1.077210542)) /* c2+c8-c6 */
1394 - MULTIPLY(tmp4
, FIX(1.471445400)), /* c4+c10 */
1396 dataptr
[DCTSIZE
*4] = (DCTELEM
)
1397 DESCALE(z2
+ z3
+ MULTIPLY(tmp1
, FIX(0.065941844)) /* c4-c6-c10 */
1398 - MULTIPLY(tmp2
, FIX(1.435427942)) /* c2 */
1399 + MULTIPLY(tmp4
, FIX(0.621472312)), /* c8 */
1401 dataptr
[DCTSIZE
*6] = (DCTELEM
)
1402 DESCALE(z1
+ z3
- MULTIPLY(tmp0
, FIX(1.714276708)) /* c2+c4-c6 */
1403 - MULTIPLY(tmp2
, FIX(0.834379234)), /* c8+c10 */
1408 tmp1
= MULTIPLY(tmp10
+ tmp11
, FIX(1.360834544)); /* c3 */
1409 tmp2
= MULTIPLY(tmp10
+ tmp12
, FIX(1.130622199)); /* c5 */
1410 tmp3
= MULTIPLY(tmp10
+ tmp13
, FIX(0.808813568)); /* c7 */
1411 tmp0
= tmp1
+ tmp2
+ tmp3
- MULTIPLY(tmp10
, FIX(1.819470145)) /* c7+c5+c3-c1 */
1412 + MULTIPLY(tmp14
, FIX(0.421479672)); /* c9 */
1413 tmp4
= MULTIPLY(tmp11
+ tmp12
, - FIX(0.808813568)); /* -c7 */
1414 tmp5
= MULTIPLY(tmp11
+ tmp13
, - FIX(1.480800167)); /* -c1 */
1415 tmp1
+= tmp4
+ tmp5
+ MULTIPLY(tmp11
, FIX(1.350258864)) /* c9+c7+c1-c3 */
1416 - MULTIPLY(tmp14
, FIX(1.130622199)); /* c5 */
1417 tmp10
= MULTIPLY(tmp12
+ tmp13
, FIX(0.421479672)); /* c9 */
1418 tmp2
+= tmp4
+ tmp10
- MULTIPLY(tmp12
, FIX(2.104122847)) /* c9+c5+c3-c7 */
1419 + MULTIPLY(tmp14
, FIX(1.480800167)); /* c1 */
1420 tmp3
+= tmp5
+ tmp10
+ MULTIPLY(tmp13
, FIX(1.381129125)) /* c1+c5-c9-c7 */
1421 - MULTIPLY(tmp14
, FIX(1.360834544)); /* c3 */
1423 dataptr
[DCTSIZE
*1] = (DCTELEM
) DESCALE(tmp0
, CONST_BITS
+2);
1424 dataptr
[DCTSIZE
*3] = (DCTELEM
) DESCALE(tmp1
, CONST_BITS
+2);
1425 dataptr
[DCTSIZE
*5] = (DCTELEM
) DESCALE(tmp2
, CONST_BITS
+2);
1426 dataptr
[DCTSIZE
*7] = (DCTELEM
) DESCALE(tmp3
, CONST_BITS
+2);
1428 dataptr
++; /* advance pointer to next column */
1429 wsptr
++; /* advance pointer to next column */
1435 * Perform the forward DCT on a 12x12 sample block.
1439 jpeg_fdct_12x12 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
1441 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
, tmp5
;
1442 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
, tmp15
;
1443 DCTELEM workspace
[8*4];
1450 /* Pass 1: process rows.
1451 * Note results are scaled up by sqrt(8) compared to a true DCT.
1452 * cK represents sqrt(2) * cos(K*pi/24).
1458 elemptr
= sample_data
[ctr
] + start_col
;
1462 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[11]);
1463 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[10]);
1464 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[9]);
1465 tmp3
= GETJSAMPLE(elemptr
[3]) + GETJSAMPLE(elemptr
[8]);
1466 tmp4
= GETJSAMPLE(elemptr
[4]) + GETJSAMPLE(elemptr
[7]);
1467 tmp5
= GETJSAMPLE(elemptr
[5]) + GETJSAMPLE(elemptr
[6]);
1469 tmp10
= tmp0
+ tmp5
;
1470 tmp13
= tmp0
- tmp5
;
1471 tmp11
= tmp1
+ tmp4
;
1472 tmp14
= tmp1
- tmp4
;
1473 tmp12
= tmp2
+ tmp3
;
1474 tmp15
= tmp2
- tmp3
;
1476 tmp0
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[11]);
1477 tmp1
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[10]);
1478 tmp2
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[9]);
1479 tmp3
= GETJSAMPLE(elemptr
[3]) - GETJSAMPLE(elemptr
[8]);
1480 tmp4
= GETJSAMPLE(elemptr
[4]) - GETJSAMPLE(elemptr
[7]);
1481 tmp5
= GETJSAMPLE(elemptr
[5]) - GETJSAMPLE(elemptr
[6]);
1483 /* Apply unsigned->signed conversion */
1484 dataptr
[0] = (DCTELEM
) (tmp10
+ tmp11
+ tmp12
- 12 * CENTERJSAMPLE
);
1485 dataptr
[6] = (DCTELEM
) (tmp13
- tmp14
- tmp15
);
1486 dataptr
[4] = (DCTELEM
)
1487 DESCALE(MULTIPLY(tmp10
- tmp12
, FIX(1.224744871)), /* c4 */
1489 dataptr
[2] = (DCTELEM
)
1490 DESCALE(tmp14
- tmp15
+ MULTIPLY(tmp13
+ tmp15
, FIX(1.366025404)), /* c2 */
1495 tmp10
= MULTIPLY(tmp1
+ tmp4
, FIX_0_541196100
); /* c9 */
1496 tmp14
= tmp10
+ MULTIPLY(tmp1
, FIX_0_765366865
); /* c3-c9 */
1497 tmp15
= tmp10
- MULTIPLY(tmp4
, FIX_1_847759065
); /* c3+c9 */
1498 tmp12
= MULTIPLY(tmp0
+ tmp2
, FIX(1.121971054)); /* c5 */
1499 tmp13
= MULTIPLY(tmp0
+ tmp3
, FIX(0.860918669)); /* c7 */
1500 tmp10
= tmp12
+ tmp13
+ tmp14
- MULTIPLY(tmp0
, FIX(0.580774953)) /* c5+c7-c1 */
1501 + MULTIPLY(tmp5
, FIX(0.184591911)); /* c11 */
1502 tmp11
= MULTIPLY(tmp2
+ tmp3
, - FIX(0.184591911)); /* -c11 */
1503 tmp12
+= tmp11
- tmp15
- MULTIPLY(tmp2
, FIX(2.339493912)) /* c1+c5-c11 */
1504 + MULTIPLY(tmp5
, FIX(0.860918669)); /* c7 */
1505 tmp13
+= tmp11
- tmp14
+ MULTIPLY(tmp3
, FIX(0.725788011)) /* c1+c11-c7 */
1506 - MULTIPLY(tmp5
, FIX(1.121971054)); /* c5 */
1507 tmp11
= tmp15
+ MULTIPLY(tmp0
- tmp3
, FIX(1.306562965)) /* c3 */
1508 - MULTIPLY(tmp2
+ tmp5
, FIX_0_541196100
); /* c9 */
1510 dataptr
[1] = (DCTELEM
) DESCALE(tmp10
, CONST_BITS
);
1511 dataptr
[3] = (DCTELEM
) DESCALE(tmp11
, CONST_BITS
);
1512 dataptr
[5] = (DCTELEM
) DESCALE(tmp12
, CONST_BITS
);
1513 dataptr
[7] = (DCTELEM
) DESCALE(tmp13
, CONST_BITS
);
1517 if (ctr
!= DCTSIZE
) {
1520 dataptr
+= DCTSIZE
; /* advance pointer to next row */
1522 dataptr
= workspace
; /* switch pointer to extended workspace */
1525 /* Pass 2: process columns.
1526 * We leave the results scaled up by an overall factor of 8.
1527 * We must also scale the output by (8/12)**2 = 4/9, which we partially
1528 * fold into the constant multipliers and final shifting:
1529 * cK now represents sqrt(2) * cos(K*pi/24) * 8/9.
1534 for (ctr
= DCTSIZE
-1; ctr
>= 0; ctr
--) {
1537 tmp0
= dataptr
[DCTSIZE
*0] + wsptr
[DCTSIZE
*3];
1538 tmp1
= dataptr
[DCTSIZE
*1] + wsptr
[DCTSIZE
*2];
1539 tmp2
= dataptr
[DCTSIZE
*2] + wsptr
[DCTSIZE
*1];
1540 tmp3
= dataptr
[DCTSIZE
*3] + wsptr
[DCTSIZE
*0];
1541 tmp4
= dataptr
[DCTSIZE
*4] + dataptr
[DCTSIZE
*7];
1542 tmp5
= dataptr
[DCTSIZE
*5] + dataptr
[DCTSIZE
*6];
1544 tmp10
= tmp0
+ tmp5
;
1545 tmp13
= tmp0
- tmp5
;
1546 tmp11
= tmp1
+ tmp4
;
1547 tmp14
= tmp1
- tmp4
;
1548 tmp12
= tmp2
+ tmp3
;
1549 tmp15
= tmp2
- tmp3
;
1551 tmp0
= dataptr
[DCTSIZE
*0] - wsptr
[DCTSIZE
*3];
1552 tmp1
= dataptr
[DCTSIZE
*1] - wsptr
[DCTSIZE
*2];
1553 tmp2
= dataptr
[DCTSIZE
*2] - wsptr
[DCTSIZE
*1];
1554 tmp3
= dataptr
[DCTSIZE
*3] - wsptr
[DCTSIZE
*0];
1555 tmp4
= dataptr
[DCTSIZE
*4] - dataptr
[DCTSIZE
*7];
1556 tmp5
= dataptr
[DCTSIZE
*5] - dataptr
[DCTSIZE
*6];
1558 dataptr
[DCTSIZE
*0] = (DCTELEM
)
1559 DESCALE(MULTIPLY(tmp10
+ tmp11
+ tmp12
, FIX(0.888888889)), /* 8/9 */
1561 dataptr
[DCTSIZE
*6] = (DCTELEM
)
1562 DESCALE(MULTIPLY(tmp13
- tmp14
- tmp15
, FIX(0.888888889)), /* 8/9 */
1564 dataptr
[DCTSIZE
*4] = (DCTELEM
)
1565 DESCALE(MULTIPLY(tmp10
- tmp12
, FIX(1.088662108)), /* c4 */
1567 dataptr
[DCTSIZE
*2] = (DCTELEM
)
1568 DESCALE(MULTIPLY(tmp14
- tmp15
, FIX(0.888888889)) + /* 8/9 */
1569 MULTIPLY(tmp13
+ tmp15
, FIX(1.214244803)), /* c2 */
1574 tmp10
= MULTIPLY(tmp1
+ tmp4
, FIX(0.481063200)); /* c9 */
1575 tmp14
= tmp10
+ MULTIPLY(tmp1
, FIX(0.680326102)); /* c3-c9 */
1576 tmp15
= tmp10
- MULTIPLY(tmp4
, FIX(1.642452502)); /* c3+c9 */
1577 tmp12
= MULTIPLY(tmp0
+ tmp2
, FIX(0.997307603)); /* c5 */
1578 tmp13
= MULTIPLY(tmp0
+ tmp3
, FIX(0.765261039)); /* c7 */
1579 tmp10
= tmp12
+ tmp13
+ tmp14
- MULTIPLY(tmp0
, FIX(0.516244403)) /* c5+c7-c1 */
1580 + MULTIPLY(tmp5
, FIX(0.164081699)); /* c11 */
1581 tmp11
= MULTIPLY(tmp2
+ tmp3
, - FIX(0.164081699)); /* -c11 */
1582 tmp12
+= tmp11
- tmp15
- MULTIPLY(tmp2
, FIX(2.079550144)) /* c1+c5-c11 */
1583 + MULTIPLY(tmp5
, FIX(0.765261039)); /* c7 */
1584 tmp13
+= tmp11
- tmp14
+ MULTIPLY(tmp3
, FIX(0.645144899)) /* c1+c11-c7 */
1585 - MULTIPLY(tmp5
, FIX(0.997307603)); /* c5 */
1586 tmp11
= tmp15
+ MULTIPLY(tmp0
- tmp3
, FIX(1.161389302)) /* c3 */
1587 - MULTIPLY(tmp2
+ tmp5
, FIX(0.481063200)); /* c9 */
1589 dataptr
[DCTSIZE
*1] = (DCTELEM
) DESCALE(tmp10
, CONST_BITS
+1);
1590 dataptr
[DCTSIZE
*3] = (DCTELEM
) DESCALE(tmp11
, CONST_BITS
+1);
1591 dataptr
[DCTSIZE
*5] = (DCTELEM
) DESCALE(tmp12
, CONST_BITS
+1);
1592 dataptr
[DCTSIZE
*7] = (DCTELEM
) DESCALE(tmp13
, CONST_BITS
+1);
1594 dataptr
++; /* advance pointer to next column */
1595 wsptr
++; /* advance pointer to next column */
1601 * Perform the forward DCT on a 13x13 sample block.
1605 jpeg_fdct_13x13 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
1607 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
, tmp5
, tmp6
;
1608 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
, tmp15
;
1610 DCTELEM workspace
[8*5];
1617 /* Pass 1: process rows.
1618 * Note results are scaled up by sqrt(8) compared to a true DCT.
1619 * cK represents sqrt(2) * cos(K*pi/26).
1625 elemptr
= sample_data
[ctr
] + start_col
;
1629 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[12]);
1630 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[11]);
1631 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[10]);
1632 tmp3
= GETJSAMPLE(elemptr
[3]) + GETJSAMPLE(elemptr
[9]);
1633 tmp4
= GETJSAMPLE(elemptr
[4]) + GETJSAMPLE(elemptr
[8]);
1634 tmp5
= GETJSAMPLE(elemptr
[5]) + GETJSAMPLE(elemptr
[7]);
1635 tmp6
= GETJSAMPLE(elemptr
[6]);
1637 tmp10
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[12]);
1638 tmp11
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[11]);
1639 tmp12
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[10]);
1640 tmp13
= GETJSAMPLE(elemptr
[3]) - GETJSAMPLE(elemptr
[9]);
1641 tmp14
= GETJSAMPLE(elemptr
[4]) - GETJSAMPLE(elemptr
[8]);
1642 tmp15
= GETJSAMPLE(elemptr
[5]) - GETJSAMPLE(elemptr
[7]);
1644 /* Apply unsigned->signed conversion */
1645 dataptr
[0] = (DCTELEM
)
1646 (tmp0
+ tmp1
+ tmp2
+ tmp3
+ tmp4
+ tmp5
+ tmp6
- 13 * CENTERJSAMPLE
);
1654 dataptr
[2] = (DCTELEM
)
1655 DESCALE(MULTIPLY(tmp0
, FIX(1.373119086)) + /* c2 */
1656 MULTIPLY(tmp1
, FIX(1.058554052)) + /* c6 */
1657 MULTIPLY(tmp2
, FIX(0.501487041)) - /* c10 */
1658 MULTIPLY(tmp3
, FIX(0.170464608)) - /* c12 */
1659 MULTIPLY(tmp4
, FIX(0.803364869)) - /* c8 */
1660 MULTIPLY(tmp5
, FIX(1.252223920)), /* c4 */
1662 z1
= MULTIPLY(tmp0
- tmp2
, FIX(1.155388986)) - /* (c4+c6)/2 */
1663 MULTIPLY(tmp3
- tmp4
, FIX(0.435816023)) - /* (c2-c10)/2 */
1664 MULTIPLY(tmp1
- tmp5
, FIX(0.316450131)); /* (c8-c12)/2 */
1665 z2
= MULTIPLY(tmp0
+ tmp2
, FIX(0.096834934)) - /* (c4-c6)/2 */
1666 MULTIPLY(tmp3
+ tmp4
, FIX(0.937303064)) + /* (c2+c10)/2 */
1667 MULTIPLY(tmp1
+ tmp5
, FIX(0.486914739)); /* (c8+c12)/2 */
1669 dataptr
[4] = (DCTELEM
) DESCALE(z1
+ z2
, CONST_BITS
);
1670 dataptr
[6] = (DCTELEM
) DESCALE(z1
- z2
, CONST_BITS
);
1674 tmp1
= MULTIPLY(tmp10
+ tmp11
, FIX(1.322312651)); /* c3 */
1675 tmp2
= MULTIPLY(tmp10
+ tmp12
, FIX(1.163874945)); /* c5 */
1676 tmp3
= MULTIPLY(tmp10
+ tmp13
, FIX(0.937797057)) + /* c7 */
1677 MULTIPLY(tmp14
+ tmp15
, FIX(0.338443458)); /* c11 */
1678 tmp0
= tmp1
+ tmp2
+ tmp3
-
1679 MULTIPLY(tmp10
, FIX(2.020082300)) + /* c3+c5+c7-c1 */
1680 MULTIPLY(tmp14
, FIX(0.318774355)); /* c9-c11 */
1681 tmp4
= MULTIPLY(tmp14
- tmp15
, FIX(0.937797057)) - /* c7 */
1682 MULTIPLY(tmp11
+ tmp12
, FIX(0.338443458)); /* c11 */
1683 tmp5
= MULTIPLY(tmp11
+ tmp13
, - FIX(1.163874945)); /* -c5 */
1684 tmp1
+= tmp4
+ tmp5
+
1685 MULTIPLY(tmp11
, FIX(0.837223564)) - /* c5+c9+c11-c3 */
1686 MULTIPLY(tmp14
, FIX(2.341699410)); /* c1+c7 */
1687 tmp6
= MULTIPLY(tmp12
+ tmp13
, - FIX(0.657217813)); /* -c9 */
1688 tmp2
+= tmp4
+ tmp6
-
1689 MULTIPLY(tmp12
, FIX(1.572116027)) + /* c1+c5-c9-c11 */
1690 MULTIPLY(tmp15
, FIX(2.260109708)); /* c3+c7 */
1691 tmp3
+= tmp5
+ tmp6
+
1692 MULTIPLY(tmp13
, FIX(2.205608352)) - /* c3+c5+c9-c7 */
1693 MULTIPLY(tmp15
, FIX(1.742345811)); /* c1+c11 */
1695 dataptr
[1] = (DCTELEM
) DESCALE(tmp0
, CONST_BITS
);
1696 dataptr
[3] = (DCTELEM
) DESCALE(tmp1
, CONST_BITS
);
1697 dataptr
[5] = (DCTELEM
) DESCALE(tmp2
, CONST_BITS
);
1698 dataptr
[7] = (DCTELEM
) DESCALE(tmp3
, CONST_BITS
);
1702 if (ctr
!= DCTSIZE
) {
1705 dataptr
+= DCTSIZE
; /* advance pointer to next row */
1707 dataptr
= workspace
; /* switch pointer to extended workspace */
1710 /* Pass 2: process columns.
1711 * We leave the results scaled up by an overall factor of 8.
1712 * We must also scale the output by (8/13)**2 = 64/169, which we partially
1713 * fold into the constant multipliers and final shifting:
1714 * cK now represents sqrt(2) * cos(K*pi/26) * 128/169.
1719 for (ctr
= DCTSIZE
-1; ctr
>= 0; ctr
--) {
1722 tmp0
= dataptr
[DCTSIZE
*0] + wsptr
[DCTSIZE
*4];
1723 tmp1
= dataptr
[DCTSIZE
*1] + wsptr
[DCTSIZE
*3];
1724 tmp2
= dataptr
[DCTSIZE
*2] + wsptr
[DCTSIZE
*2];
1725 tmp3
= dataptr
[DCTSIZE
*3] + wsptr
[DCTSIZE
*1];
1726 tmp4
= dataptr
[DCTSIZE
*4] + wsptr
[DCTSIZE
*0];
1727 tmp5
= dataptr
[DCTSIZE
*5] + dataptr
[DCTSIZE
*7];
1728 tmp6
= dataptr
[DCTSIZE
*6];
1730 tmp10
= dataptr
[DCTSIZE
*0] - wsptr
[DCTSIZE
*4];
1731 tmp11
= dataptr
[DCTSIZE
*1] - wsptr
[DCTSIZE
*3];
1732 tmp12
= dataptr
[DCTSIZE
*2] - wsptr
[DCTSIZE
*2];
1733 tmp13
= dataptr
[DCTSIZE
*3] - wsptr
[DCTSIZE
*1];
1734 tmp14
= dataptr
[DCTSIZE
*4] - wsptr
[DCTSIZE
*0];
1735 tmp15
= dataptr
[DCTSIZE
*5] - dataptr
[DCTSIZE
*7];
1737 dataptr
[DCTSIZE
*0] = (DCTELEM
)
1738 DESCALE(MULTIPLY(tmp0
+ tmp1
+ tmp2
+ tmp3
+ tmp4
+ tmp5
+ tmp6
,
1739 FIX(0.757396450)), /* 128/169 */
1748 dataptr
[DCTSIZE
*2] = (DCTELEM
)
1749 DESCALE(MULTIPLY(tmp0
, FIX(1.039995521)) + /* c2 */
1750 MULTIPLY(tmp1
, FIX(0.801745081)) + /* c6 */
1751 MULTIPLY(tmp2
, FIX(0.379824504)) - /* c10 */
1752 MULTIPLY(tmp3
, FIX(0.129109289)) - /* c12 */
1753 MULTIPLY(tmp4
, FIX(0.608465700)) - /* c8 */
1754 MULTIPLY(tmp5
, FIX(0.948429952)), /* c4 */
1756 z1
= MULTIPLY(tmp0
- tmp2
, FIX(0.875087516)) - /* (c4+c6)/2 */
1757 MULTIPLY(tmp3
- tmp4
, FIX(0.330085509)) - /* (c2-c10)/2 */
1758 MULTIPLY(tmp1
- tmp5
, FIX(0.239678205)); /* (c8-c12)/2 */
1759 z2
= MULTIPLY(tmp0
+ tmp2
, FIX(0.073342435)) - /* (c4-c6)/2 */
1760 MULTIPLY(tmp3
+ tmp4
, FIX(0.709910013)) + /* (c2+c10)/2 */
1761 MULTIPLY(tmp1
+ tmp5
, FIX(0.368787494)); /* (c8+c12)/2 */
1763 dataptr
[DCTSIZE
*4] = (DCTELEM
) DESCALE(z1
+ z2
, CONST_BITS
+1);
1764 dataptr
[DCTSIZE
*6] = (DCTELEM
) DESCALE(z1
- z2
, CONST_BITS
+1);
1768 tmp1
= MULTIPLY(tmp10
+ tmp11
, FIX(1.001514908)); /* c3 */
1769 tmp2
= MULTIPLY(tmp10
+ tmp12
, FIX(0.881514751)); /* c5 */
1770 tmp3
= MULTIPLY(tmp10
+ tmp13
, FIX(0.710284161)) + /* c7 */
1771 MULTIPLY(tmp14
+ tmp15
, FIX(0.256335874)); /* c11 */
1772 tmp0
= tmp1
+ tmp2
+ tmp3
-
1773 MULTIPLY(tmp10
, FIX(1.530003162)) + /* c3+c5+c7-c1 */
1774 MULTIPLY(tmp14
, FIX(0.241438564)); /* c9-c11 */
1775 tmp4
= MULTIPLY(tmp14
- tmp15
, FIX(0.710284161)) - /* c7 */
1776 MULTIPLY(tmp11
+ tmp12
, FIX(0.256335874)); /* c11 */
1777 tmp5
= MULTIPLY(tmp11
+ tmp13
, - FIX(0.881514751)); /* -c5 */
1778 tmp1
+= tmp4
+ tmp5
+
1779 MULTIPLY(tmp11
, FIX(0.634110155)) - /* c5+c9+c11-c3 */
1780 MULTIPLY(tmp14
, FIX(1.773594819)); /* c1+c7 */
1781 tmp6
= MULTIPLY(tmp12
+ tmp13
, - FIX(0.497774438)); /* -c9 */
1782 tmp2
+= tmp4
+ tmp6
-
1783 MULTIPLY(tmp12
, FIX(1.190715098)) + /* c1+c5-c9-c11 */
1784 MULTIPLY(tmp15
, FIX(1.711799069)); /* c3+c7 */
1785 tmp3
+= tmp5
+ tmp6
+
1786 MULTIPLY(tmp13
, FIX(1.670519935)) - /* c3+c5+c9-c7 */
1787 MULTIPLY(tmp15
, FIX(1.319646532)); /* c1+c11 */
1789 dataptr
[DCTSIZE
*1] = (DCTELEM
) DESCALE(tmp0
, CONST_BITS
+1);
1790 dataptr
[DCTSIZE
*3] = (DCTELEM
) DESCALE(tmp1
, CONST_BITS
+1);
1791 dataptr
[DCTSIZE
*5] = (DCTELEM
) DESCALE(tmp2
, CONST_BITS
+1);
1792 dataptr
[DCTSIZE
*7] = (DCTELEM
) DESCALE(tmp3
, CONST_BITS
+1);
1794 dataptr
++; /* advance pointer to next column */
1795 wsptr
++; /* advance pointer to next column */
1801 * Perform the forward DCT on a 14x14 sample block.
1805 jpeg_fdct_14x14 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
1807 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
, tmp5
, tmp6
;
1808 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
, tmp15
, tmp16
;
1809 DCTELEM workspace
[8*6];
1816 /* Pass 1: process rows.
1817 * Note results are scaled up by sqrt(8) compared to a true DCT.
1818 * cK represents sqrt(2) * cos(K*pi/28).
1824 elemptr
= sample_data
[ctr
] + start_col
;
1828 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[13]);
1829 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[12]);
1830 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[11]);
1831 tmp13
= GETJSAMPLE(elemptr
[3]) + GETJSAMPLE(elemptr
[10]);
1832 tmp4
= GETJSAMPLE(elemptr
[4]) + GETJSAMPLE(elemptr
[9]);
1833 tmp5
= GETJSAMPLE(elemptr
[5]) + GETJSAMPLE(elemptr
[8]);
1834 tmp6
= GETJSAMPLE(elemptr
[6]) + GETJSAMPLE(elemptr
[7]);
1836 tmp10
= tmp0
+ tmp6
;
1837 tmp14
= tmp0
- tmp6
;
1838 tmp11
= tmp1
+ tmp5
;
1839 tmp15
= tmp1
- tmp5
;
1840 tmp12
= tmp2
+ tmp4
;
1841 tmp16
= tmp2
- tmp4
;
1843 tmp0
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[13]);
1844 tmp1
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[12]);
1845 tmp2
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[11]);
1846 tmp3
= GETJSAMPLE(elemptr
[3]) - GETJSAMPLE(elemptr
[10]);
1847 tmp4
= GETJSAMPLE(elemptr
[4]) - GETJSAMPLE(elemptr
[9]);
1848 tmp5
= GETJSAMPLE(elemptr
[5]) - GETJSAMPLE(elemptr
[8]);
1849 tmp6
= GETJSAMPLE(elemptr
[6]) - GETJSAMPLE(elemptr
[7]);
1851 /* Apply unsigned->signed conversion */
1852 dataptr
[0] = (DCTELEM
)
1853 (tmp10
+ tmp11
+ tmp12
+ tmp13
- 14 * CENTERJSAMPLE
);
1855 dataptr
[4] = (DCTELEM
)
1856 DESCALE(MULTIPLY(tmp10
- tmp13
, FIX(1.274162392)) + /* c4 */
1857 MULTIPLY(tmp11
- tmp13
, FIX(0.314692123)) - /* c12 */
1858 MULTIPLY(tmp12
- tmp13
, FIX(0.881747734)), /* c8 */
1861 tmp10
= MULTIPLY(tmp14
+ tmp15
, FIX(1.105676686)); /* c6 */
1863 dataptr
[2] = (DCTELEM
)
1864 DESCALE(tmp10
+ MULTIPLY(tmp14
, FIX(0.273079590)) /* c2-c6 */
1865 + MULTIPLY(tmp16
, FIX(0.613604268)), /* c10 */
1867 dataptr
[6] = (DCTELEM
)
1868 DESCALE(tmp10
- MULTIPLY(tmp15
, FIX(1.719280954)) /* c6+c10 */
1869 - MULTIPLY(tmp16
, FIX(1.378756276)), /* c2 */
1874 tmp10
= tmp1
+ tmp2
;
1875 tmp11
= tmp5
- tmp4
;
1876 dataptr
[7] = (DCTELEM
) (tmp0
- tmp10
+ tmp3
- tmp11
- tmp6
);
1877 tmp3
<<= CONST_BITS
;
1878 tmp10
= MULTIPLY(tmp10
, - FIX(0.158341681)); /* -c13 */
1879 tmp11
= MULTIPLY(tmp11
, FIX(1.405321284)); /* c1 */
1880 tmp10
+= tmp11
- tmp3
;
1881 tmp11
= MULTIPLY(tmp0
+ tmp2
, FIX(1.197448846)) + /* c5 */
1882 MULTIPLY(tmp4
+ tmp6
, FIX(0.752406978)); /* c9 */
1883 dataptr
[5] = (DCTELEM
)
1884 DESCALE(tmp10
+ tmp11
- MULTIPLY(tmp2
, FIX(2.373959773)) /* c3+c5-c13 */
1885 + MULTIPLY(tmp4
, FIX(1.119999435)), /* c1+c11-c9 */
1887 tmp12
= MULTIPLY(tmp0
+ tmp1
, FIX(1.334852607)) + /* c3 */
1888 MULTIPLY(tmp5
- tmp6
, FIX(0.467085129)); /* c11 */
1889 dataptr
[3] = (DCTELEM
)
1890 DESCALE(tmp10
+ tmp12
- MULTIPLY(tmp1
, FIX(0.424103948)) /* c3-c9-c13 */
1891 - MULTIPLY(tmp5
, FIX(3.069855259)), /* c1+c5+c11 */
1893 dataptr
[1] = (DCTELEM
)
1894 DESCALE(tmp11
+ tmp12
+ tmp3
+ tmp6
-
1895 MULTIPLY(tmp0
+ tmp6
, FIX(1.126980169)), /* c3+c5-c1 */
1900 if (ctr
!= DCTSIZE
) {
1903 dataptr
+= DCTSIZE
; /* advance pointer to next row */
1905 dataptr
= workspace
; /* switch pointer to extended workspace */
1908 /* Pass 2: process columns.
1909 * We leave the results scaled up by an overall factor of 8.
1910 * We must also scale the output by (8/14)**2 = 16/49, which we partially
1911 * fold into the constant multipliers and final shifting:
1912 * cK now represents sqrt(2) * cos(K*pi/28) * 32/49.
1917 for (ctr
= DCTSIZE
-1; ctr
>= 0; ctr
--) {
1920 tmp0
= dataptr
[DCTSIZE
*0] + wsptr
[DCTSIZE
*5];
1921 tmp1
= dataptr
[DCTSIZE
*1] + wsptr
[DCTSIZE
*4];
1922 tmp2
= dataptr
[DCTSIZE
*2] + wsptr
[DCTSIZE
*3];
1923 tmp13
= dataptr
[DCTSIZE
*3] + wsptr
[DCTSIZE
*2];
1924 tmp4
= dataptr
[DCTSIZE
*4] + wsptr
[DCTSIZE
*1];
1925 tmp5
= dataptr
[DCTSIZE
*5] + wsptr
[DCTSIZE
*0];
1926 tmp6
= dataptr
[DCTSIZE
*6] + dataptr
[DCTSIZE
*7];
1928 tmp10
= tmp0
+ tmp6
;
1929 tmp14
= tmp0
- tmp6
;
1930 tmp11
= tmp1
+ tmp5
;
1931 tmp15
= tmp1
- tmp5
;
1932 tmp12
= tmp2
+ tmp4
;
1933 tmp16
= tmp2
- tmp4
;
1935 tmp0
= dataptr
[DCTSIZE
*0] - wsptr
[DCTSIZE
*5];
1936 tmp1
= dataptr
[DCTSIZE
*1] - wsptr
[DCTSIZE
*4];
1937 tmp2
= dataptr
[DCTSIZE
*2] - wsptr
[DCTSIZE
*3];
1938 tmp3
= dataptr
[DCTSIZE
*3] - wsptr
[DCTSIZE
*2];
1939 tmp4
= dataptr
[DCTSIZE
*4] - wsptr
[DCTSIZE
*1];
1940 tmp5
= dataptr
[DCTSIZE
*5] - wsptr
[DCTSIZE
*0];
1941 tmp6
= dataptr
[DCTSIZE
*6] - dataptr
[DCTSIZE
*7];
1943 dataptr
[DCTSIZE
*0] = (DCTELEM
)
1944 DESCALE(MULTIPLY(tmp10
+ tmp11
+ tmp12
+ tmp13
,
1945 FIX(0.653061224)), /* 32/49 */
1948 dataptr
[DCTSIZE
*4] = (DCTELEM
)
1949 DESCALE(MULTIPLY(tmp10
- tmp13
, FIX(0.832106052)) + /* c4 */
1950 MULTIPLY(tmp11
- tmp13
, FIX(0.205513223)) - /* c12 */
1951 MULTIPLY(tmp12
- tmp13
, FIX(0.575835255)), /* c8 */
1954 tmp10
= MULTIPLY(tmp14
+ tmp15
, FIX(0.722074570)); /* c6 */
1956 dataptr
[DCTSIZE
*2] = (DCTELEM
)
1957 DESCALE(tmp10
+ MULTIPLY(tmp14
, FIX(0.178337691)) /* c2-c6 */
1958 + MULTIPLY(tmp16
, FIX(0.400721155)), /* c10 */
1960 dataptr
[DCTSIZE
*6] = (DCTELEM
)
1961 DESCALE(tmp10
- MULTIPLY(tmp15
, FIX(1.122795725)) /* c6+c10 */
1962 - MULTIPLY(tmp16
, FIX(0.900412262)), /* c2 */
1967 tmp10
= tmp1
+ tmp2
;
1968 tmp11
= tmp5
- tmp4
;
1969 dataptr
[DCTSIZE
*7] = (DCTELEM
)
1970 DESCALE(MULTIPLY(tmp0
- tmp10
+ tmp3
- tmp11
- tmp6
,
1971 FIX(0.653061224)), /* 32/49 */
1973 tmp3
= MULTIPLY(tmp3
, FIX(0.653061224)); /* 32/49 */
1974 tmp10
= MULTIPLY(tmp10
, - FIX(0.103406812)); /* -c13 */
1975 tmp11
= MULTIPLY(tmp11
, FIX(0.917760839)); /* c1 */
1976 tmp10
+= tmp11
- tmp3
;
1977 tmp11
= MULTIPLY(tmp0
+ tmp2
, FIX(0.782007410)) + /* c5 */
1978 MULTIPLY(tmp4
+ tmp6
, FIX(0.491367823)); /* c9 */
1979 dataptr
[DCTSIZE
*5] = (DCTELEM
)
1980 DESCALE(tmp10
+ tmp11
- MULTIPLY(tmp2
, FIX(1.550341076)) /* c3+c5-c13 */
1981 + MULTIPLY(tmp4
, FIX(0.731428202)), /* c1+c11-c9 */
1983 tmp12
= MULTIPLY(tmp0
+ tmp1
, FIX(0.871740478)) + /* c3 */
1984 MULTIPLY(tmp5
- tmp6
, FIX(0.305035186)); /* c11 */
1985 dataptr
[DCTSIZE
*3] = (DCTELEM
)
1986 DESCALE(tmp10
+ tmp12
- MULTIPLY(tmp1
, FIX(0.276965844)) /* c3-c9-c13 */
1987 - MULTIPLY(tmp5
, FIX(2.004803435)), /* c1+c5+c11 */
1989 dataptr
[DCTSIZE
*1] = (DCTELEM
)
1990 DESCALE(tmp11
+ tmp12
+ tmp3
1991 - MULTIPLY(tmp0
, FIX(0.735987049)) /* c3+c5-c1 */
1992 - MULTIPLY(tmp6
, FIX(0.082925825)), /* c9-c11-c13 */
1995 dataptr
++; /* advance pointer to next column */
1996 wsptr
++; /* advance pointer to next column */
2002 * Perform the forward DCT on a 15x15 sample block.
2006 jpeg_fdct_15x15 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
2008 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
, tmp5
, tmp6
, tmp7
;
2009 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
, tmp15
, tmp16
;
2011 DCTELEM workspace
[8*7];
2018 /* Pass 1: process rows.
2019 * Note results are scaled up by sqrt(8) compared to a true DCT.
2020 * cK represents sqrt(2) * cos(K*pi/30).
2026 elemptr
= sample_data
[ctr
] + start_col
;
2030 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[14]);
2031 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[13]);
2032 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[12]);
2033 tmp3
= GETJSAMPLE(elemptr
[3]) + GETJSAMPLE(elemptr
[11]);
2034 tmp4
= GETJSAMPLE(elemptr
[4]) + GETJSAMPLE(elemptr
[10]);
2035 tmp5
= GETJSAMPLE(elemptr
[5]) + GETJSAMPLE(elemptr
[9]);
2036 tmp6
= GETJSAMPLE(elemptr
[6]) + GETJSAMPLE(elemptr
[8]);
2037 tmp7
= GETJSAMPLE(elemptr
[7]);
2039 tmp10
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[14]);
2040 tmp11
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[13]);
2041 tmp12
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[12]);
2042 tmp13
= GETJSAMPLE(elemptr
[3]) - GETJSAMPLE(elemptr
[11]);
2043 tmp14
= GETJSAMPLE(elemptr
[4]) - GETJSAMPLE(elemptr
[10]);
2044 tmp15
= GETJSAMPLE(elemptr
[5]) - GETJSAMPLE(elemptr
[9]);
2045 tmp16
= GETJSAMPLE(elemptr
[6]) - GETJSAMPLE(elemptr
[8]);
2047 z1
= tmp0
+ tmp4
+ tmp5
;
2048 z2
= tmp1
+ tmp3
+ tmp6
;
2050 /* Apply unsigned->signed conversion */
2051 dataptr
[0] = (DCTELEM
) (z1
+ z2
+ z3
- 15 * CENTERJSAMPLE
);
2053 dataptr
[6] = (DCTELEM
)
2054 DESCALE(MULTIPLY(z1
- z3
, FIX(1.144122806)) - /* c6 */
2055 MULTIPLY(z2
- z3
, FIX(0.437016024)), /* c12 */
2057 tmp2
+= ((tmp1
+ tmp4
) >> 1) - tmp7
- tmp7
;
2058 z1
= MULTIPLY(tmp3
- tmp2
, FIX(1.531135173)) - /* c2+c14 */
2059 MULTIPLY(tmp6
- tmp2
, FIX(2.238241955)); /* c4+c8 */
2060 z2
= MULTIPLY(tmp5
- tmp2
, FIX(0.798468008)) - /* c8-c14 */
2061 MULTIPLY(tmp0
- tmp2
, FIX(0.091361227)); /* c2-c4 */
2062 z3
= MULTIPLY(tmp0
- tmp3
, FIX(1.383309603)) + /* c2 */
2063 MULTIPLY(tmp6
- tmp5
, FIX(0.946293579)) + /* c8 */
2064 MULTIPLY(tmp1
- tmp4
, FIX(0.790569415)); /* (c6+c12)/2 */
2066 dataptr
[2] = (DCTELEM
) DESCALE(z1
+ z3
, CONST_BITS
);
2067 dataptr
[4] = (DCTELEM
) DESCALE(z2
+ z3
, CONST_BITS
);
2071 tmp2
= MULTIPLY(tmp10
- tmp12
- tmp13
+ tmp15
+ tmp16
,
2072 FIX(1.224744871)); /* c5 */
2073 tmp1
= MULTIPLY(tmp10
- tmp14
- tmp15
, FIX(1.344997024)) + /* c3 */
2074 MULTIPLY(tmp11
- tmp13
- tmp16
, FIX(0.831253876)); /* c9 */
2075 tmp12
= MULTIPLY(tmp12
, FIX(1.224744871)); /* c5 */
2076 tmp4
= MULTIPLY(tmp10
- tmp16
, FIX(1.406466353)) + /* c1 */
2077 MULTIPLY(tmp11
+ tmp14
, FIX(1.344997024)) + /* c3 */
2078 MULTIPLY(tmp13
+ tmp15
, FIX(0.575212477)); /* c11 */
2079 tmp0
= MULTIPLY(tmp13
, FIX(0.475753014)) - /* c7-c11 */
2080 MULTIPLY(tmp14
, FIX(0.513743148)) + /* c3-c9 */
2081 MULTIPLY(tmp16
, FIX(1.700497885)) + tmp4
+ tmp12
; /* c1+c13 */
2082 tmp3
= MULTIPLY(tmp10
, - FIX(0.355500862)) - /* -(c1-c7) */
2083 MULTIPLY(tmp11
, FIX(2.176250899)) - /* c3+c9 */
2084 MULTIPLY(tmp15
, FIX(0.869244010)) + tmp4
- tmp12
; /* c11+c13 */
2086 dataptr
[1] = (DCTELEM
) DESCALE(tmp0
, CONST_BITS
);
2087 dataptr
[3] = (DCTELEM
) DESCALE(tmp1
, CONST_BITS
);
2088 dataptr
[5] = (DCTELEM
) DESCALE(tmp2
, CONST_BITS
);
2089 dataptr
[7] = (DCTELEM
) DESCALE(tmp3
, CONST_BITS
);
2093 if (ctr
!= DCTSIZE
) {
2096 dataptr
+= DCTSIZE
; /* advance pointer to next row */
2098 dataptr
= workspace
; /* switch pointer to extended workspace */
2101 /* Pass 2: process columns.
2102 * We leave the results scaled up by an overall factor of 8.
2103 * We must also scale the output by (8/15)**2 = 64/225, which we partially
2104 * fold into the constant multipliers and final shifting:
2105 * cK now represents sqrt(2) * cos(K*pi/30) * 256/225.
2110 for (ctr
= DCTSIZE
-1; ctr
>= 0; ctr
--) {
2113 tmp0
= dataptr
[DCTSIZE
*0] + wsptr
[DCTSIZE
*6];
2114 tmp1
= dataptr
[DCTSIZE
*1] + wsptr
[DCTSIZE
*5];
2115 tmp2
= dataptr
[DCTSIZE
*2] + wsptr
[DCTSIZE
*4];
2116 tmp3
= dataptr
[DCTSIZE
*3] + wsptr
[DCTSIZE
*3];
2117 tmp4
= dataptr
[DCTSIZE
*4] + wsptr
[DCTSIZE
*2];
2118 tmp5
= dataptr
[DCTSIZE
*5] + wsptr
[DCTSIZE
*1];
2119 tmp6
= dataptr
[DCTSIZE
*6] + wsptr
[DCTSIZE
*0];
2120 tmp7
= dataptr
[DCTSIZE
*7];
2122 tmp10
= dataptr
[DCTSIZE
*0] - wsptr
[DCTSIZE
*6];
2123 tmp11
= dataptr
[DCTSIZE
*1] - wsptr
[DCTSIZE
*5];
2124 tmp12
= dataptr
[DCTSIZE
*2] - wsptr
[DCTSIZE
*4];
2125 tmp13
= dataptr
[DCTSIZE
*3] - wsptr
[DCTSIZE
*3];
2126 tmp14
= dataptr
[DCTSIZE
*4] - wsptr
[DCTSIZE
*2];
2127 tmp15
= dataptr
[DCTSIZE
*5] - wsptr
[DCTSIZE
*1];
2128 tmp16
= dataptr
[DCTSIZE
*6] - wsptr
[DCTSIZE
*0];
2130 z1
= tmp0
+ tmp4
+ tmp5
;
2131 z2
= tmp1
+ tmp3
+ tmp6
;
2133 dataptr
[DCTSIZE
*0] = (DCTELEM
)
2134 DESCALE(MULTIPLY(z1
+ z2
+ z3
, FIX(1.137777778)), /* 256/225 */
2137 dataptr
[DCTSIZE
*6] = (DCTELEM
)
2138 DESCALE(MULTIPLY(z1
- z3
, FIX(1.301757503)) - /* c6 */
2139 MULTIPLY(z2
- z3
, FIX(0.497227121)), /* c12 */
2141 tmp2
+= ((tmp1
+ tmp4
) >> 1) - tmp7
- tmp7
;
2142 z1
= MULTIPLY(tmp3
- tmp2
, FIX(1.742091575)) - /* c2+c14 */
2143 MULTIPLY(tmp6
- tmp2
, FIX(2.546621957)); /* c4+c8 */
2144 z2
= MULTIPLY(tmp5
- tmp2
, FIX(0.908479156)) - /* c8-c14 */
2145 MULTIPLY(tmp0
- tmp2
, FIX(0.103948774)); /* c2-c4 */
2146 z3
= MULTIPLY(tmp0
- tmp3
, FIX(1.573898926)) + /* c2 */
2147 MULTIPLY(tmp6
- tmp5
, FIX(1.076671805)) + /* c8 */
2148 MULTIPLY(tmp1
- tmp4
, FIX(0.899492312)); /* (c6+c12)/2 */
2150 dataptr
[DCTSIZE
*2] = (DCTELEM
) DESCALE(z1
+ z3
, CONST_BITS
+2);
2151 dataptr
[DCTSIZE
*4] = (DCTELEM
) DESCALE(z2
+ z3
, CONST_BITS
+2);
2155 tmp2
= MULTIPLY(tmp10
- tmp12
- tmp13
+ tmp15
+ tmp16
,
2156 FIX(1.393487498)); /* c5 */
2157 tmp1
= MULTIPLY(tmp10
- tmp14
- tmp15
, FIX(1.530307725)) + /* c3 */
2158 MULTIPLY(tmp11
- tmp13
- tmp16
, FIX(0.945782187)); /* c9 */
2159 tmp12
= MULTIPLY(tmp12
, FIX(1.393487498)); /* c5 */
2160 tmp4
= MULTIPLY(tmp10
- tmp16
, FIX(1.600246161)) + /* c1 */
2161 MULTIPLY(tmp11
+ tmp14
, FIX(1.530307725)) + /* c3 */
2162 MULTIPLY(tmp13
+ tmp15
, FIX(0.654463974)); /* c11 */
2163 tmp0
= MULTIPLY(tmp13
, FIX(0.541301207)) - /* c7-c11 */
2164 MULTIPLY(tmp14
, FIX(0.584525538)) + /* c3-c9 */
2165 MULTIPLY(tmp16
, FIX(1.934788705)) + tmp4
+ tmp12
; /* c1+c13 */
2166 tmp3
= MULTIPLY(tmp10
, - FIX(0.404480980)) - /* -(c1-c7) */
2167 MULTIPLY(tmp11
, FIX(2.476089912)) - /* c3+c9 */
2168 MULTIPLY(tmp15
, FIX(0.989006518)) + tmp4
- tmp12
; /* c11+c13 */
2170 dataptr
[DCTSIZE
*1] = (DCTELEM
) DESCALE(tmp0
, CONST_BITS
+2);
2171 dataptr
[DCTSIZE
*3] = (DCTELEM
) DESCALE(tmp1
, CONST_BITS
+2);
2172 dataptr
[DCTSIZE
*5] = (DCTELEM
) DESCALE(tmp2
, CONST_BITS
+2);
2173 dataptr
[DCTSIZE
*7] = (DCTELEM
) DESCALE(tmp3
, CONST_BITS
+2);
2175 dataptr
++; /* advance pointer to next column */
2176 wsptr
++; /* advance pointer to next column */
2182 * Perform the forward DCT on a 16x16 sample block.
2186 jpeg_fdct_16x16 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
2188 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
, tmp5
, tmp6
, tmp7
;
2189 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
, tmp15
, tmp16
, tmp17
;
2190 DCTELEM workspace
[DCTSIZE2
];
2197 /* Pass 1: process rows.
2198 * Note results are scaled up by sqrt(8) compared to a true DCT;
2199 * furthermore, we scale the results by 2**PASS1_BITS.
2200 * cK represents sqrt(2) * cos(K*pi/32).
2206 elemptr
= sample_data
[ctr
] + start_col
;
2210 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[15]);
2211 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[14]);
2212 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[13]);
2213 tmp3
= GETJSAMPLE(elemptr
[3]) + GETJSAMPLE(elemptr
[12]);
2214 tmp4
= GETJSAMPLE(elemptr
[4]) + GETJSAMPLE(elemptr
[11]);
2215 tmp5
= GETJSAMPLE(elemptr
[5]) + GETJSAMPLE(elemptr
[10]);
2216 tmp6
= GETJSAMPLE(elemptr
[6]) + GETJSAMPLE(elemptr
[9]);
2217 tmp7
= GETJSAMPLE(elemptr
[7]) + GETJSAMPLE(elemptr
[8]);
2219 tmp10
= tmp0
+ tmp7
;
2220 tmp14
= tmp0
- tmp7
;
2221 tmp11
= tmp1
+ tmp6
;
2222 tmp15
= tmp1
- tmp6
;
2223 tmp12
= tmp2
+ tmp5
;
2224 tmp16
= tmp2
- tmp5
;
2225 tmp13
= tmp3
+ tmp4
;
2226 tmp17
= tmp3
- tmp4
;
2228 tmp0
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[15]);
2229 tmp1
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[14]);
2230 tmp2
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[13]);
2231 tmp3
= GETJSAMPLE(elemptr
[3]) - GETJSAMPLE(elemptr
[12]);
2232 tmp4
= GETJSAMPLE(elemptr
[4]) - GETJSAMPLE(elemptr
[11]);
2233 tmp5
= GETJSAMPLE(elemptr
[5]) - GETJSAMPLE(elemptr
[10]);
2234 tmp6
= GETJSAMPLE(elemptr
[6]) - GETJSAMPLE(elemptr
[9]);
2235 tmp7
= GETJSAMPLE(elemptr
[7]) - GETJSAMPLE(elemptr
[8]);
2237 /* Apply unsigned->signed conversion */
2238 dataptr
[0] = (DCTELEM
)
2239 ((tmp10
+ tmp11
+ tmp12
+ tmp13
- 16 * CENTERJSAMPLE
) << PASS1_BITS
);
2240 dataptr
[4] = (DCTELEM
)
2241 DESCALE(MULTIPLY(tmp10
- tmp13
, FIX(1.306562965)) + /* c4[16] = c2[8] */
2242 MULTIPLY(tmp11
- tmp12
, FIX_0_541196100
), /* c12[16] = c6[8] */
2243 CONST_BITS
-PASS1_BITS
);
2245 tmp10
= MULTIPLY(tmp17
- tmp15
, FIX(0.275899379)) + /* c14[16] = c7[8] */
2246 MULTIPLY(tmp14
- tmp16
, FIX(1.387039845)); /* c2[16] = c1[8] */
2248 dataptr
[2] = (DCTELEM
)
2249 DESCALE(tmp10
+ MULTIPLY(tmp15
, FIX(1.451774982)) /* c6+c14 */
2250 + MULTIPLY(tmp16
, FIX(2.172734804)), /* c2+c10 */
2251 CONST_BITS
-PASS1_BITS
);
2252 dataptr
[6] = (DCTELEM
)
2253 DESCALE(tmp10
- MULTIPLY(tmp14
, FIX(0.211164243)) /* c2-c6 */
2254 - MULTIPLY(tmp17
, FIX(1.061594338)), /* c10+c14 */
2255 CONST_BITS
-PASS1_BITS
);
2259 tmp11
= MULTIPLY(tmp0
+ tmp1
, FIX(1.353318001)) + /* c3 */
2260 MULTIPLY(tmp6
- tmp7
, FIX(0.410524528)); /* c13 */
2261 tmp12
= MULTIPLY(tmp0
+ tmp2
, FIX(1.247225013)) + /* c5 */
2262 MULTIPLY(tmp5
+ tmp7
, FIX(0.666655658)); /* c11 */
2263 tmp13
= MULTIPLY(tmp0
+ tmp3
, FIX(1.093201867)) + /* c7 */
2264 MULTIPLY(tmp4
- tmp7
, FIX(0.897167586)); /* c9 */
2265 tmp14
= MULTIPLY(tmp1
+ tmp2
, FIX(0.138617169)) + /* c15 */
2266 MULTIPLY(tmp6
- tmp5
, FIX(1.407403738)); /* c1 */
2267 tmp15
= MULTIPLY(tmp1
+ tmp3
, - FIX(0.666655658)) + /* -c11 */
2268 MULTIPLY(tmp4
+ tmp6
, - FIX(1.247225013)); /* -c5 */
2269 tmp16
= MULTIPLY(tmp2
+ tmp3
, - FIX(1.353318001)) + /* -c3 */
2270 MULTIPLY(tmp5
- tmp4
, FIX(0.410524528)); /* c13 */
2271 tmp10
= tmp11
+ tmp12
+ tmp13
-
2272 MULTIPLY(tmp0
, FIX(2.286341144)) + /* c7+c5+c3-c1 */
2273 MULTIPLY(tmp7
, FIX(0.779653625)); /* c15+c13-c11+c9 */
2274 tmp11
+= tmp14
+ tmp15
+ MULTIPLY(tmp1
, FIX(0.071888074)) /* c9-c3-c15+c11 */
2275 - MULTIPLY(tmp6
, FIX(1.663905119)); /* c7+c13+c1-c5 */
2276 tmp12
+= tmp14
+ tmp16
- MULTIPLY(tmp2
, FIX(1.125726048)) /* c7+c5+c15-c3 */
2277 + MULTIPLY(tmp5
, FIX(1.227391138)); /* c9-c11+c1-c13 */
2278 tmp13
+= tmp15
+ tmp16
+ MULTIPLY(tmp3
, FIX(1.065388962)) /* c15+c3+c11-c7 */
2279 + MULTIPLY(tmp4
, FIX(2.167985692)); /* c1+c13+c5-c9 */
2281 dataptr
[1] = (DCTELEM
) DESCALE(tmp10
, CONST_BITS
-PASS1_BITS
);
2282 dataptr
[3] = (DCTELEM
) DESCALE(tmp11
, CONST_BITS
-PASS1_BITS
);
2283 dataptr
[5] = (DCTELEM
) DESCALE(tmp12
, CONST_BITS
-PASS1_BITS
);
2284 dataptr
[7] = (DCTELEM
) DESCALE(tmp13
, CONST_BITS
-PASS1_BITS
);
2288 if (ctr
!= DCTSIZE
) {
2289 if (ctr
== DCTSIZE
* 2)
2291 dataptr
+= DCTSIZE
; /* advance pointer to next row */
2293 dataptr
= workspace
; /* switch pointer to extended workspace */
2296 /* Pass 2: process columns.
2297 * We remove the PASS1_BITS scaling, but leave the results scaled up
2298 * by an overall factor of 8.
2299 * We must also scale the output by (8/16)**2 = 1/2**2.
2300 * cK represents sqrt(2) * cos(K*pi/32).
2305 for (ctr
= DCTSIZE
-1; ctr
>= 0; ctr
--) {
2308 tmp0
= dataptr
[DCTSIZE
*0] + wsptr
[DCTSIZE
*7];
2309 tmp1
= dataptr
[DCTSIZE
*1] + wsptr
[DCTSIZE
*6];
2310 tmp2
= dataptr
[DCTSIZE
*2] + wsptr
[DCTSIZE
*5];
2311 tmp3
= dataptr
[DCTSIZE
*3] + wsptr
[DCTSIZE
*4];
2312 tmp4
= dataptr
[DCTSIZE
*4] + wsptr
[DCTSIZE
*3];
2313 tmp5
= dataptr
[DCTSIZE
*5] + wsptr
[DCTSIZE
*2];
2314 tmp6
= dataptr
[DCTSIZE
*6] + wsptr
[DCTSIZE
*1];
2315 tmp7
= dataptr
[DCTSIZE
*7] + wsptr
[DCTSIZE
*0];
2317 tmp10
= tmp0
+ tmp7
;
2318 tmp14
= tmp0
- tmp7
;
2319 tmp11
= tmp1
+ tmp6
;
2320 tmp15
= tmp1
- tmp6
;
2321 tmp12
= tmp2
+ tmp5
;
2322 tmp16
= tmp2
- tmp5
;
2323 tmp13
= tmp3
+ tmp4
;
2324 tmp17
= tmp3
- tmp4
;
2326 tmp0
= dataptr
[DCTSIZE
*0] - wsptr
[DCTSIZE
*7];
2327 tmp1
= dataptr
[DCTSIZE
*1] - wsptr
[DCTSIZE
*6];
2328 tmp2
= dataptr
[DCTSIZE
*2] - wsptr
[DCTSIZE
*5];
2329 tmp3
= dataptr
[DCTSIZE
*3] - wsptr
[DCTSIZE
*4];
2330 tmp4
= dataptr
[DCTSIZE
*4] - wsptr
[DCTSIZE
*3];
2331 tmp5
= dataptr
[DCTSIZE
*5] - wsptr
[DCTSIZE
*2];
2332 tmp6
= dataptr
[DCTSIZE
*6] - wsptr
[DCTSIZE
*1];
2333 tmp7
= dataptr
[DCTSIZE
*7] - wsptr
[DCTSIZE
*0];
2335 dataptr
[DCTSIZE
*0] = (DCTELEM
)
2336 DESCALE(tmp10
+ tmp11
+ tmp12
+ tmp13
, PASS1_BITS
+2);
2337 dataptr
[DCTSIZE
*4] = (DCTELEM
)
2338 DESCALE(MULTIPLY(tmp10
- tmp13
, FIX(1.306562965)) + /* c4[16] = c2[8] */
2339 MULTIPLY(tmp11
- tmp12
, FIX_0_541196100
), /* c12[16] = c6[8] */
2340 CONST_BITS
+PASS1_BITS
+2);
2342 tmp10
= MULTIPLY(tmp17
- tmp15
, FIX(0.275899379)) + /* c14[16] = c7[8] */
2343 MULTIPLY(tmp14
- tmp16
, FIX(1.387039845)); /* c2[16] = c1[8] */
2345 dataptr
[DCTSIZE
*2] = (DCTELEM
)
2346 DESCALE(tmp10
+ MULTIPLY(tmp15
, FIX(1.451774982)) /* c6+c14 */
2347 + MULTIPLY(tmp16
, FIX(2.172734804)), /* c2+10 */
2348 CONST_BITS
+PASS1_BITS
+2);
2349 dataptr
[DCTSIZE
*6] = (DCTELEM
)
2350 DESCALE(tmp10
- MULTIPLY(tmp14
, FIX(0.211164243)) /* c2-c6 */
2351 - MULTIPLY(tmp17
, FIX(1.061594338)), /* c10+c14 */
2352 CONST_BITS
+PASS1_BITS
+2);
2356 tmp11
= MULTIPLY(tmp0
+ tmp1
, FIX(1.353318001)) + /* c3 */
2357 MULTIPLY(tmp6
- tmp7
, FIX(0.410524528)); /* c13 */
2358 tmp12
= MULTIPLY(tmp0
+ tmp2
, FIX(1.247225013)) + /* c5 */
2359 MULTIPLY(tmp5
+ tmp7
, FIX(0.666655658)); /* c11 */
2360 tmp13
= MULTIPLY(tmp0
+ tmp3
, FIX(1.093201867)) + /* c7 */
2361 MULTIPLY(tmp4
- tmp7
, FIX(0.897167586)); /* c9 */
2362 tmp14
= MULTIPLY(tmp1
+ tmp2
, FIX(0.138617169)) + /* c15 */
2363 MULTIPLY(tmp6
- tmp5
, FIX(1.407403738)); /* c1 */
2364 tmp15
= MULTIPLY(tmp1
+ tmp3
, - FIX(0.666655658)) + /* -c11 */
2365 MULTIPLY(tmp4
+ tmp6
, - FIX(1.247225013)); /* -c5 */
2366 tmp16
= MULTIPLY(tmp2
+ tmp3
, - FIX(1.353318001)) + /* -c3 */
2367 MULTIPLY(tmp5
- tmp4
, FIX(0.410524528)); /* c13 */
2368 tmp10
= tmp11
+ tmp12
+ tmp13
-
2369 MULTIPLY(tmp0
, FIX(2.286341144)) + /* c7+c5+c3-c1 */
2370 MULTIPLY(tmp7
, FIX(0.779653625)); /* c15+c13-c11+c9 */
2371 tmp11
+= tmp14
+ tmp15
+ MULTIPLY(tmp1
, FIX(0.071888074)) /* c9-c3-c15+c11 */
2372 - MULTIPLY(tmp6
, FIX(1.663905119)); /* c7+c13+c1-c5 */
2373 tmp12
+= tmp14
+ tmp16
- MULTIPLY(tmp2
, FIX(1.125726048)) /* c7+c5+c15-c3 */
2374 + MULTIPLY(tmp5
, FIX(1.227391138)); /* c9-c11+c1-c13 */
2375 tmp13
+= tmp15
+ tmp16
+ MULTIPLY(tmp3
, FIX(1.065388962)) /* c15+c3+c11-c7 */
2376 + MULTIPLY(tmp4
, FIX(2.167985692)); /* c1+c13+c5-c9 */
2378 dataptr
[DCTSIZE
*1] = (DCTELEM
) DESCALE(tmp10
, CONST_BITS
+PASS1_BITS
+2);
2379 dataptr
[DCTSIZE
*3] = (DCTELEM
) DESCALE(tmp11
, CONST_BITS
+PASS1_BITS
+2);
2380 dataptr
[DCTSIZE
*5] = (DCTELEM
) DESCALE(tmp12
, CONST_BITS
+PASS1_BITS
+2);
2381 dataptr
[DCTSIZE
*7] = (DCTELEM
) DESCALE(tmp13
, CONST_BITS
+PASS1_BITS
+2);
2383 dataptr
++; /* advance pointer to next column */
2384 wsptr
++; /* advance pointer to next column */
2390 * Perform the forward DCT on a 16x8 sample block.
2392 * 16-point FDCT in pass 1 (rows), 8-point in pass 2 (columns).
2396 jpeg_fdct_16x8 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
2398 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
, tmp5
, tmp6
, tmp7
;
2399 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
, tmp15
, tmp16
, tmp17
;
2406 /* Pass 1: process rows.
2407 * Note results are scaled up by sqrt(8) compared to a true DCT;
2408 * furthermore, we scale the results by 2**PASS1_BITS.
2409 * 16-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/32).
2414 for (ctr
= 0; ctr
< DCTSIZE
; ctr
++) {
2415 elemptr
= sample_data
[ctr
] + start_col
;
2419 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[15]);
2420 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[14]);
2421 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[13]);
2422 tmp3
= GETJSAMPLE(elemptr
[3]) + GETJSAMPLE(elemptr
[12]);
2423 tmp4
= GETJSAMPLE(elemptr
[4]) + GETJSAMPLE(elemptr
[11]);
2424 tmp5
= GETJSAMPLE(elemptr
[5]) + GETJSAMPLE(elemptr
[10]);
2425 tmp6
= GETJSAMPLE(elemptr
[6]) + GETJSAMPLE(elemptr
[9]);
2426 tmp7
= GETJSAMPLE(elemptr
[7]) + GETJSAMPLE(elemptr
[8]);
2428 tmp10
= tmp0
+ tmp7
;
2429 tmp14
= tmp0
- tmp7
;
2430 tmp11
= tmp1
+ tmp6
;
2431 tmp15
= tmp1
- tmp6
;
2432 tmp12
= tmp2
+ tmp5
;
2433 tmp16
= tmp2
- tmp5
;
2434 tmp13
= tmp3
+ tmp4
;
2435 tmp17
= tmp3
- tmp4
;
2437 tmp0
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[15]);
2438 tmp1
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[14]);
2439 tmp2
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[13]);
2440 tmp3
= GETJSAMPLE(elemptr
[3]) - GETJSAMPLE(elemptr
[12]);
2441 tmp4
= GETJSAMPLE(elemptr
[4]) - GETJSAMPLE(elemptr
[11]);
2442 tmp5
= GETJSAMPLE(elemptr
[5]) - GETJSAMPLE(elemptr
[10]);
2443 tmp6
= GETJSAMPLE(elemptr
[6]) - GETJSAMPLE(elemptr
[9]);
2444 tmp7
= GETJSAMPLE(elemptr
[7]) - GETJSAMPLE(elemptr
[8]);
2446 /* Apply unsigned->signed conversion */
2447 dataptr
[0] = (DCTELEM
)
2448 ((tmp10
+ tmp11
+ tmp12
+ tmp13
- 16 * CENTERJSAMPLE
) << PASS1_BITS
);
2449 dataptr
[4] = (DCTELEM
)
2450 DESCALE(MULTIPLY(tmp10
- tmp13
, FIX(1.306562965)) + /* c4[16] = c2[8] */
2451 MULTIPLY(tmp11
- tmp12
, FIX_0_541196100
), /* c12[16] = c6[8] */
2452 CONST_BITS
-PASS1_BITS
);
2454 tmp10
= MULTIPLY(tmp17
- tmp15
, FIX(0.275899379)) + /* c14[16] = c7[8] */
2455 MULTIPLY(tmp14
- tmp16
, FIX(1.387039845)); /* c2[16] = c1[8] */
2457 dataptr
[2] = (DCTELEM
)
2458 DESCALE(tmp10
+ MULTIPLY(tmp15
, FIX(1.451774982)) /* c6+c14 */
2459 + MULTIPLY(tmp16
, FIX(2.172734804)), /* c2+c10 */
2460 CONST_BITS
-PASS1_BITS
);
2461 dataptr
[6] = (DCTELEM
)
2462 DESCALE(tmp10
- MULTIPLY(tmp14
, FIX(0.211164243)) /* c2-c6 */
2463 - MULTIPLY(tmp17
, FIX(1.061594338)), /* c10+c14 */
2464 CONST_BITS
-PASS1_BITS
);
2468 tmp11
= MULTIPLY(tmp0
+ tmp1
, FIX(1.353318001)) + /* c3 */
2469 MULTIPLY(tmp6
- tmp7
, FIX(0.410524528)); /* c13 */
2470 tmp12
= MULTIPLY(tmp0
+ tmp2
, FIX(1.247225013)) + /* c5 */
2471 MULTIPLY(tmp5
+ tmp7
, FIX(0.666655658)); /* c11 */
2472 tmp13
= MULTIPLY(tmp0
+ tmp3
, FIX(1.093201867)) + /* c7 */
2473 MULTIPLY(tmp4
- tmp7
, FIX(0.897167586)); /* c9 */
2474 tmp14
= MULTIPLY(tmp1
+ tmp2
, FIX(0.138617169)) + /* c15 */
2475 MULTIPLY(tmp6
- tmp5
, FIX(1.407403738)); /* c1 */
2476 tmp15
= MULTIPLY(tmp1
+ tmp3
, - FIX(0.666655658)) + /* -c11 */
2477 MULTIPLY(tmp4
+ tmp6
, - FIX(1.247225013)); /* -c5 */
2478 tmp16
= MULTIPLY(tmp2
+ tmp3
, - FIX(1.353318001)) + /* -c3 */
2479 MULTIPLY(tmp5
- tmp4
, FIX(0.410524528)); /* c13 */
2480 tmp10
= tmp11
+ tmp12
+ tmp13
-
2481 MULTIPLY(tmp0
, FIX(2.286341144)) + /* c7+c5+c3-c1 */
2482 MULTIPLY(tmp7
, FIX(0.779653625)); /* c15+c13-c11+c9 */
2483 tmp11
+= tmp14
+ tmp15
+ MULTIPLY(tmp1
, FIX(0.071888074)) /* c9-c3-c15+c11 */
2484 - MULTIPLY(tmp6
, FIX(1.663905119)); /* c7+c13+c1-c5 */
2485 tmp12
+= tmp14
+ tmp16
- MULTIPLY(tmp2
, FIX(1.125726048)) /* c7+c5+c15-c3 */
2486 + MULTIPLY(tmp5
, FIX(1.227391138)); /* c9-c11+c1-c13 */
2487 tmp13
+= tmp15
+ tmp16
+ MULTIPLY(tmp3
, FIX(1.065388962)) /* c15+c3+c11-c7 */
2488 + MULTIPLY(tmp4
, FIX(2.167985692)); /* c1+c13+c5-c9 */
2490 dataptr
[1] = (DCTELEM
) DESCALE(tmp10
, CONST_BITS
-PASS1_BITS
);
2491 dataptr
[3] = (DCTELEM
) DESCALE(tmp11
, CONST_BITS
-PASS1_BITS
);
2492 dataptr
[5] = (DCTELEM
) DESCALE(tmp12
, CONST_BITS
-PASS1_BITS
);
2493 dataptr
[7] = (DCTELEM
) DESCALE(tmp13
, CONST_BITS
-PASS1_BITS
);
2495 dataptr
+= DCTSIZE
; /* advance pointer to next row */
2498 /* Pass 2: process columns.
2499 * We remove the PASS1_BITS scaling, but leave the results scaled up
2500 * by an overall factor of 8.
2501 * We must also scale the output by 8/16 = 1/2.
2502 * 8-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
2506 for (ctr
= DCTSIZE
-1; ctr
>= 0; ctr
--) {
2507 /* Even part per LL&M figure 1 --- note that published figure is faulty;
2508 * rotator "c1" should be "c6".
2511 tmp0
= dataptr
[DCTSIZE
*0] + dataptr
[DCTSIZE
*7];
2512 tmp1
= dataptr
[DCTSIZE
*1] + dataptr
[DCTSIZE
*6];
2513 tmp2
= dataptr
[DCTSIZE
*2] + dataptr
[DCTSIZE
*5];
2514 tmp3
= dataptr
[DCTSIZE
*3] + dataptr
[DCTSIZE
*4];
2516 tmp10
= tmp0
+ tmp3
;
2517 tmp12
= tmp0
- tmp3
;
2518 tmp11
= tmp1
+ tmp2
;
2519 tmp13
= tmp1
- tmp2
;
2521 tmp0
= dataptr
[DCTSIZE
*0] - dataptr
[DCTSIZE
*7];
2522 tmp1
= dataptr
[DCTSIZE
*1] - dataptr
[DCTSIZE
*6];
2523 tmp2
= dataptr
[DCTSIZE
*2] - dataptr
[DCTSIZE
*5];
2524 tmp3
= dataptr
[DCTSIZE
*3] - dataptr
[DCTSIZE
*4];
2526 dataptr
[DCTSIZE
*0] = (DCTELEM
) DESCALE(tmp10
+ tmp11
, PASS1_BITS
+1);
2527 dataptr
[DCTSIZE
*4] = (DCTELEM
) DESCALE(tmp10
- tmp11
, PASS1_BITS
+1);
2529 z1
= MULTIPLY(tmp12
+ tmp13
, FIX_0_541196100
); /* c6 */
2530 dataptr
[DCTSIZE
*2] = (DCTELEM
)
2531 DESCALE(z1
+ MULTIPLY(tmp12
, FIX_0_765366865
), /* c2-c6 */
2532 CONST_BITS
+PASS1_BITS
+1);
2533 dataptr
[DCTSIZE
*6] = (DCTELEM
)
2534 DESCALE(z1
- MULTIPLY(tmp13
, FIX_1_847759065
), /* c2+c6 */
2535 CONST_BITS
+PASS1_BITS
+1);
2537 /* Odd part per figure 8 --- note paper omits factor of sqrt(2).
2538 * i0..i3 in the paper are tmp0..tmp3 here.
2541 tmp12
= tmp0
+ tmp2
;
2542 tmp13
= tmp1
+ tmp3
;
2544 z1
= MULTIPLY(tmp12
+ tmp13
, FIX_1_175875602
); /* c3 */
2545 tmp12
= MULTIPLY(tmp12
, - FIX_0_390180644
); /* -c3+c5 */
2546 tmp13
= MULTIPLY(tmp13
, - FIX_1_961570560
); /* -c3-c5 */
2550 z1
= MULTIPLY(tmp0
+ tmp3
, - FIX_0_899976223
); /* -c3+c7 */
2551 tmp0
= MULTIPLY(tmp0
, FIX_1_501321110
); /* c1+c3-c5-c7 */
2552 tmp3
= MULTIPLY(tmp3
, FIX_0_298631336
); /* -c1+c3+c5-c7 */
2556 z1
= MULTIPLY(tmp1
+ tmp2
, - FIX_2_562915447
); /* -c1-c3 */
2557 tmp1
= MULTIPLY(tmp1
, FIX_3_072711026
); /* c1+c3+c5-c7 */
2558 tmp2
= MULTIPLY(tmp2
, FIX_2_053119869
); /* c1+c3-c5+c7 */
2562 dataptr
[DCTSIZE
*1] = (DCTELEM
) DESCALE(tmp0
, CONST_BITS
+PASS1_BITS
+1);
2563 dataptr
[DCTSIZE
*3] = (DCTELEM
) DESCALE(tmp1
, CONST_BITS
+PASS1_BITS
+1);
2564 dataptr
[DCTSIZE
*5] = (DCTELEM
) DESCALE(tmp2
, CONST_BITS
+PASS1_BITS
+1);
2565 dataptr
[DCTSIZE
*7] = (DCTELEM
) DESCALE(tmp3
, CONST_BITS
+PASS1_BITS
+1);
2567 dataptr
++; /* advance pointer to next column */
2573 * Perform the forward DCT on a 14x7 sample block.
2575 * 14-point FDCT in pass 1 (rows), 7-point in pass 2 (columns).
2579 jpeg_fdct_14x7 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
2581 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
, tmp5
, tmp6
;
2582 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
, tmp15
, tmp16
;
2589 /* Zero bottom row of output coefficient block. */
2590 MEMZERO(&data
[DCTSIZE
*7], SIZEOF(DCTELEM
) * DCTSIZE
);
2592 /* Pass 1: process rows.
2593 * Note results are scaled up by sqrt(8) compared to a true DCT;
2594 * furthermore, we scale the results by 2**PASS1_BITS.
2595 * 14-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/28).
2599 for (ctr
= 0; ctr
< 7; ctr
++) {
2600 elemptr
= sample_data
[ctr
] + start_col
;
2604 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[13]);
2605 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[12]);
2606 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[11]);
2607 tmp13
= GETJSAMPLE(elemptr
[3]) + GETJSAMPLE(elemptr
[10]);
2608 tmp4
= GETJSAMPLE(elemptr
[4]) + GETJSAMPLE(elemptr
[9]);
2609 tmp5
= GETJSAMPLE(elemptr
[5]) + GETJSAMPLE(elemptr
[8]);
2610 tmp6
= GETJSAMPLE(elemptr
[6]) + GETJSAMPLE(elemptr
[7]);
2612 tmp10
= tmp0
+ tmp6
;
2613 tmp14
= tmp0
- tmp6
;
2614 tmp11
= tmp1
+ tmp5
;
2615 tmp15
= tmp1
- tmp5
;
2616 tmp12
= tmp2
+ tmp4
;
2617 tmp16
= tmp2
- tmp4
;
2619 tmp0
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[13]);
2620 tmp1
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[12]);
2621 tmp2
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[11]);
2622 tmp3
= GETJSAMPLE(elemptr
[3]) - GETJSAMPLE(elemptr
[10]);
2623 tmp4
= GETJSAMPLE(elemptr
[4]) - GETJSAMPLE(elemptr
[9]);
2624 tmp5
= GETJSAMPLE(elemptr
[5]) - GETJSAMPLE(elemptr
[8]);
2625 tmp6
= GETJSAMPLE(elemptr
[6]) - GETJSAMPLE(elemptr
[7]);
2627 /* Apply unsigned->signed conversion */
2628 dataptr
[0] = (DCTELEM
)
2629 ((tmp10
+ tmp11
+ tmp12
+ tmp13
- 14 * CENTERJSAMPLE
) << PASS1_BITS
);
2631 dataptr
[4] = (DCTELEM
)
2632 DESCALE(MULTIPLY(tmp10
- tmp13
, FIX(1.274162392)) + /* c4 */
2633 MULTIPLY(tmp11
- tmp13
, FIX(0.314692123)) - /* c12 */
2634 MULTIPLY(tmp12
- tmp13
, FIX(0.881747734)), /* c8 */
2635 CONST_BITS
-PASS1_BITS
);
2637 tmp10
= MULTIPLY(tmp14
+ tmp15
, FIX(1.105676686)); /* c6 */
2639 dataptr
[2] = (DCTELEM
)
2640 DESCALE(tmp10
+ MULTIPLY(tmp14
, FIX(0.273079590)) /* c2-c6 */
2641 + MULTIPLY(tmp16
, FIX(0.613604268)), /* c10 */
2642 CONST_BITS
-PASS1_BITS
);
2643 dataptr
[6] = (DCTELEM
)
2644 DESCALE(tmp10
- MULTIPLY(tmp15
, FIX(1.719280954)) /* c6+c10 */
2645 - MULTIPLY(tmp16
, FIX(1.378756276)), /* c2 */
2646 CONST_BITS
-PASS1_BITS
);
2650 tmp10
= tmp1
+ tmp2
;
2651 tmp11
= tmp5
- tmp4
;
2652 dataptr
[7] = (DCTELEM
) ((tmp0
- tmp10
+ tmp3
- tmp11
- tmp6
) << PASS1_BITS
);
2653 tmp3
<<= CONST_BITS
;
2654 tmp10
= MULTIPLY(tmp10
, - FIX(0.158341681)); /* -c13 */
2655 tmp11
= MULTIPLY(tmp11
, FIX(1.405321284)); /* c1 */
2656 tmp10
+= tmp11
- tmp3
;
2657 tmp11
= MULTIPLY(tmp0
+ tmp2
, FIX(1.197448846)) + /* c5 */
2658 MULTIPLY(tmp4
+ tmp6
, FIX(0.752406978)); /* c9 */
2659 dataptr
[5] = (DCTELEM
)
2660 DESCALE(tmp10
+ tmp11
- MULTIPLY(tmp2
, FIX(2.373959773)) /* c3+c5-c13 */
2661 + MULTIPLY(tmp4
, FIX(1.119999435)), /* c1+c11-c9 */
2662 CONST_BITS
-PASS1_BITS
);
2663 tmp12
= MULTIPLY(tmp0
+ tmp1
, FIX(1.334852607)) + /* c3 */
2664 MULTIPLY(tmp5
- tmp6
, FIX(0.467085129)); /* c11 */
2665 dataptr
[3] = (DCTELEM
)
2666 DESCALE(tmp10
+ tmp12
- MULTIPLY(tmp1
, FIX(0.424103948)) /* c3-c9-c13 */
2667 - MULTIPLY(tmp5
, FIX(3.069855259)), /* c1+c5+c11 */
2668 CONST_BITS
-PASS1_BITS
);
2669 dataptr
[1] = (DCTELEM
)
2670 DESCALE(tmp11
+ tmp12
+ tmp3
+ tmp6
-
2671 MULTIPLY(tmp0
+ tmp6
, FIX(1.126980169)), /* c3+c5-c1 */
2672 CONST_BITS
-PASS1_BITS
);
2674 dataptr
+= DCTSIZE
; /* advance pointer to next row */
2677 /* Pass 2: process columns.
2678 * We remove the PASS1_BITS scaling, but leave the results scaled up
2679 * by an overall factor of 8.
2680 * We must also scale the output by (8/14)*(8/7) = 32/49, which we
2681 * partially fold into the constant multipliers and final shifting:
2682 * 7-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/14) * 64/49.
2686 for (ctr
= DCTSIZE
-1; ctr
>= 0; ctr
--) {
2689 tmp0
= dataptr
[DCTSIZE
*0] + dataptr
[DCTSIZE
*6];
2690 tmp1
= dataptr
[DCTSIZE
*1] + dataptr
[DCTSIZE
*5];
2691 tmp2
= dataptr
[DCTSIZE
*2] + dataptr
[DCTSIZE
*4];
2692 tmp3
= dataptr
[DCTSIZE
*3];
2694 tmp10
= dataptr
[DCTSIZE
*0] - dataptr
[DCTSIZE
*6];
2695 tmp11
= dataptr
[DCTSIZE
*1] - dataptr
[DCTSIZE
*5];
2696 tmp12
= dataptr
[DCTSIZE
*2] - dataptr
[DCTSIZE
*4];
2699 dataptr
[DCTSIZE
*0] = (DCTELEM
)
2700 DESCALE(MULTIPLY(z1
+ tmp1
+ tmp3
, FIX(1.306122449)), /* 64/49 */
2701 CONST_BITS
+PASS1_BITS
+1);
2705 z1
= MULTIPLY(z1
, FIX(0.461784020)); /* (c2+c6-c4)/2 */
2706 z2
= MULTIPLY(tmp0
- tmp2
, FIX(1.202428084)); /* (c2+c4-c6)/2 */
2707 z3
= MULTIPLY(tmp1
- tmp2
, FIX(0.411026446)); /* c6 */
2708 dataptr
[DCTSIZE
*2] = (DCTELEM
) DESCALE(z1
+ z2
+ z3
, CONST_BITS
+PASS1_BITS
+1);
2710 z2
= MULTIPLY(tmp0
- tmp1
, FIX(1.151670509)); /* c4 */
2711 dataptr
[DCTSIZE
*4] = (DCTELEM
)
2712 DESCALE(z2
+ z3
- MULTIPLY(tmp1
- tmp3
, FIX(0.923568041)), /* c2+c6-c4 */
2713 CONST_BITS
+PASS1_BITS
+1);
2714 dataptr
[DCTSIZE
*6] = (DCTELEM
) DESCALE(z1
+ z2
, CONST_BITS
+PASS1_BITS
+1);
2718 tmp1
= MULTIPLY(tmp10
+ tmp11
, FIX(1.221765677)); /* (c3+c1-c5)/2 */
2719 tmp2
= MULTIPLY(tmp10
- tmp11
, FIX(0.222383464)); /* (c3+c5-c1)/2 */
2722 tmp2
= MULTIPLY(tmp11
+ tmp12
, - FIX(1.800824523)); /* -c1 */
2724 tmp3
= MULTIPLY(tmp10
+ tmp12
, FIX(0.801442310)); /* c5 */
2726 tmp2
+= tmp3
+ MULTIPLY(tmp12
, FIX(2.443531355)); /* c3+c1-c5 */
2728 dataptr
[DCTSIZE
*1] = (DCTELEM
) DESCALE(tmp0
, CONST_BITS
+PASS1_BITS
+1);
2729 dataptr
[DCTSIZE
*3] = (DCTELEM
) DESCALE(tmp1
, CONST_BITS
+PASS1_BITS
+1);
2730 dataptr
[DCTSIZE
*5] = (DCTELEM
) DESCALE(tmp2
, CONST_BITS
+PASS1_BITS
+1);
2732 dataptr
++; /* advance pointer to next column */
2738 * Perform the forward DCT on a 12x6 sample block.
2740 * 12-point FDCT in pass 1 (rows), 6-point in pass 2 (columns).
2744 jpeg_fdct_12x6 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
2746 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
, tmp5
;
2747 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
, tmp15
;
2753 /* Zero 2 bottom rows of output coefficient block. */
2754 MEMZERO(&data
[DCTSIZE
*6], SIZEOF(DCTELEM
) * DCTSIZE
* 2);
2756 /* Pass 1: process rows.
2757 * Note results are scaled up by sqrt(8) compared to a true DCT;
2758 * furthermore, we scale the results by 2**PASS1_BITS.
2759 * 12-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/24).
2763 for (ctr
= 0; ctr
< 6; ctr
++) {
2764 elemptr
= sample_data
[ctr
] + start_col
;
2768 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[11]);
2769 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[10]);
2770 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[9]);
2771 tmp3
= GETJSAMPLE(elemptr
[3]) + GETJSAMPLE(elemptr
[8]);
2772 tmp4
= GETJSAMPLE(elemptr
[4]) + GETJSAMPLE(elemptr
[7]);
2773 tmp5
= GETJSAMPLE(elemptr
[5]) + GETJSAMPLE(elemptr
[6]);
2775 tmp10
= tmp0
+ tmp5
;
2776 tmp13
= tmp0
- tmp5
;
2777 tmp11
= tmp1
+ tmp4
;
2778 tmp14
= tmp1
- tmp4
;
2779 tmp12
= tmp2
+ tmp3
;
2780 tmp15
= tmp2
- tmp3
;
2782 tmp0
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[11]);
2783 tmp1
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[10]);
2784 tmp2
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[9]);
2785 tmp3
= GETJSAMPLE(elemptr
[3]) - GETJSAMPLE(elemptr
[8]);
2786 tmp4
= GETJSAMPLE(elemptr
[4]) - GETJSAMPLE(elemptr
[7]);
2787 tmp5
= GETJSAMPLE(elemptr
[5]) - GETJSAMPLE(elemptr
[6]);
2789 /* Apply unsigned->signed conversion */
2790 dataptr
[0] = (DCTELEM
)
2791 ((tmp10
+ tmp11
+ tmp12
- 12 * CENTERJSAMPLE
) << PASS1_BITS
);
2792 dataptr
[6] = (DCTELEM
) ((tmp13
- tmp14
- tmp15
) << PASS1_BITS
);
2793 dataptr
[4] = (DCTELEM
)
2794 DESCALE(MULTIPLY(tmp10
- tmp12
, FIX(1.224744871)), /* c4 */
2795 CONST_BITS
-PASS1_BITS
);
2796 dataptr
[2] = (DCTELEM
)
2797 DESCALE(tmp14
- tmp15
+ MULTIPLY(tmp13
+ tmp15
, FIX(1.366025404)), /* c2 */
2798 CONST_BITS
-PASS1_BITS
);
2802 tmp10
= MULTIPLY(tmp1
+ tmp4
, FIX_0_541196100
); /* c9 */
2803 tmp14
= tmp10
+ MULTIPLY(tmp1
, FIX_0_765366865
); /* c3-c9 */
2804 tmp15
= tmp10
- MULTIPLY(tmp4
, FIX_1_847759065
); /* c3+c9 */
2805 tmp12
= MULTIPLY(tmp0
+ tmp2
, FIX(1.121971054)); /* c5 */
2806 tmp13
= MULTIPLY(tmp0
+ tmp3
, FIX(0.860918669)); /* c7 */
2807 tmp10
= tmp12
+ tmp13
+ tmp14
- MULTIPLY(tmp0
, FIX(0.580774953)) /* c5+c7-c1 */
2808 + MULTIPLY(tmp5
, FIX(0.184591911)); /* c11 */
2809 tmp11
= MULTIPLY(tmp2
+ tmp3
, - FIX(0.184591911)); /* -c11 */
2810 tmp12
+= tmp11
- tmp15
- MULTIPLY(tmp2
, FIX(2.339493912)) /* c1+c5-c11 */
2811 + MULTIPLY(tmp5
, FIX(0.860918669)); /* c7 */
2812 tmp13
+= tmp11
- tmp14
+ MULTIPLY(tmp3
, FIX(0.725788011)) /* c1+c11-c7 */
2813 - MULTIPLY(tmp5
, FIX(1.121971054)); /* c5 */
2814 tmp11
= tmp15
+ MULTIPLY(tmp0
- tmp3
, FIX(1.306562965)) /* c3 */
2815 - MULTIPLY(tmp2
+ tmp5
, FIX_0_541196100
); /* c9 */
2817 dataptr
[1] = (DCTELEM
) DESCALE(tmp10
, CONST_BITS
-PASS1_BITS
);
2818 dataptr
[3] = (DCTELEM
) DESCALE(tmp11
, CONST_BITS
-PASS1_BITS
);
2819 dataptr
[5] = (DCTELEM
) DESCALE(tmp12
, CONST_BITS
-PASS1_BITS
);
2820 dataptr
[7] = (DCTELEM
) DESCALE(tmp13
, CONST_BITS
-PASS1_BITS
);
2822 dataptr
+= DCTSIZE
; /* advance pointer to next row */
2825 /* Pass 2: process columns.
2826 * We remove the PASS1_BITS scaling, but leave the results scaled up
2827 * by an overall factor of 8.
2828 * We must also scale the output by (8/12)*(8/6) = 8/9, which we
2829 * partially fold into the constant multipliers and final shifting:
2830 * 6-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/12) * 16/9.
2834 for (ctr
= DCTSIZE
-1; ctr
>= 0; ctr
--) {
2837 tmp0
= dataptr
[DCTSIZE
*0] + dataptr
[DCTSIZE
*5];
2838 tmp11
= dataptr
[DCTSIZE
*1] + dataptr
[DCTSIZE
*4];
2839 tmp2
= dataptr
[DCTSIZE
*2] + dataptr
[DCTSIZE
*3];
2841 tmp10
= tmp0
+ tmp2
;
2842 tmp12
= tmp0
- tmp2
;
2844 tmp0
= dataptr
[DCTSIZE
*0] - dataptr
[DCTSIZE
*5];
2845 tmp1
= dataptr
[DCTSIZE
*1] - dataptr
[DCTSIZE
*4];
2846 tmp2
= dataptr
[DCTSIZE
*2] - dataptr
[DCTSIZE
*3];
2848 dataptr
[DCTSIZE
*0] = (DCTELEM
)
2849 DESCALE(MULTIPLY(tmp10
+ tmp11
, FIX(1.777777778)), /* 16/9 */
2850 CONST_BITS
+PASS1_BITS
+1);
2851 dataptr
[DCTSIZE
*2] = (DCTELEM
)
2852 DESCALE(MULTIPLY(tmp12
, FIX(2.177324216)), /* c2 */
2853 CONST_BITS
+PASS1_BITS
+1);
2854 dataptr
[DCTSIZE
*4] = (DCTELEM
)
2855 DESCALE(MULTIPLY(tmp10
- tmp11
- tmp11
, FIX(1.257078722)), /* c4 */
2856 CONST_BITS
+PASS1_BITS
+1);
2860 tmp10
= MULTIPLY(tmp0
+ tmp2
, FIX(0.650711829)); /* c5 */
2862 dataptr
[DCTSIZE
*1] = (DCTELEM
)
2863 DESCALE(tmp10
+ MULTIPLY(tmp0
+ tmp1
, FIX(1.777777778)), /* 16/9 */
2864 CONST_BITS
+PASS1_BITS
+1);
2865 dataptr
[DCTSIZE
*3] = (DCTELEM
)
2866 DESCALE(MULTIPLY(tmp0
- tmp1
- tmp2
, FIX(1.777777778)), /* 16/9 */
2867 CONST_BITS
+PASS1_BITS
+1);
2868 dataptr
[DCTSIZE
*5] = (DCTELEM
)
2869 DESCALE(tmp10
+ MULTIPLY(tmp2
- tmp1
, FIX(1.777777778)), /* 16/9 */
2870 CONST_BITS
+PASS1_BITS
+1);
2872 dataptr
++; /* advance pointer to next column */
2878 * Perform the forward DCT on a 10x5 sample block.
2880 * 10-point FDCT in pass 1 (rows), 5-point in pass 2 (columns).
2884 jpeg_fdct_10x5 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
2886 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
;
2887 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
;
2893 /* Zero 3 bottom rows of output coefficient block. */
2894 MEMZERO(&data
[DCTSIZE
*5], SIZEOF(DCTELEM
) * DCTSIZE
* 3);
2896 /* Pass 1: process rows.
2897 * Note results are scaled up by sqrt(8) compared to a true DCT;
2898 * furthermore, we scale the results by 2**PASS1_BITS.
2899 * 10-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/20).
2903 for (ctr
= 0; ctr
< 5; ctr
++) {
2904 elemptr
= sample_data
[ctr
] + start_col
;
2908 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[9]);
2909 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[8]);
2910 tmp12
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[7]);
2911 tmp3
= GETJSAMPLE(elemptr
[3]) + GETJSAMPLE(elemptr
[6]);
2912 tmp4
= GETJSAMPLE(elemptr
[4]) + GETJSAMPLE(elemptr
[5]);
2914 tmp10
= tmp0
+ tmp4
;
2915 tmp13
= tmp0
- tmp4
;
2916 tmp11
= tmp1
+ tmp3
;
2917 tmp14
= tmp1
- tmp3
;
2919 tmp0
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[9]);
2920 tmp1
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[8]);
2921 tmp2
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[7]);
2922 tmp3
= GETJSAMPLE(elemptr
[3]) - GETJSAMPLE(elemptr
[6]);
2923 tmp4
= GETJSAMPLE(elemptr
[4]) - GETJSAMPLE(elemptr
[5]);
2925 /* Apply unsigned->signed conversion */
2926 dataptr
[0] = (DCTELEM
)
2927 ((tmp10
+ tmp11
+ tmp12
- 10 * CENTERJSAMPLE
) << PASS1_BITS
);
2929 dataptr
[4] = (DCTELEM
)
2930 DESCALE(MULTIPLY(tmp10
- tmp12
, FIX(1.144122806)) - /* c4 */
2931 MULTIPLY(tmp11
- tmp12
, FIX(0.437016024)), /* c8 */
2932 CONST_BITS
-PASS1_BITS
);
2933 tmp10
= MULTIPLY(tmp13
+ tmp14
, FIX(0.831253876)); /* c6 */
2934 dataptr
[2] = (DCTELEM
)
2935 DESCALE(tmp10
+ MULTIPLY(tmp13
, FIX(0.513743148)), /* c2-c6 */
2936 CONST_BITS
-PASS1_BITS
);
2937 dataptr
[6] = (DCTELEM
)
2938 DESCALE(tmp10
- MULTIPLY(tmp14
, FIX(2.176250899)), /* c2+c6 */
2939 CONST_BITS
-PASS1_BITS
);
2943 tmp10
= tmp0
+ tmp4
;
2944 tmp11
= tmp1
- tmp3
;
2945 dataptr
[5] = (DCTELEM
) ((tmp10
- tmp11
- tmp2
) << PASS1_BITS
);
2946 tmp2
<<= CONST_BITS
;
2947 dataptr
[1] = (DCTELEM
)
2948 DESCALE(MULTIPLY(tmp0
, FIX(1.396802247)) + /* c1 */
2949 MULTIPLY(tmp1
, FIX(1.260073511)) + tmp2
+ /* c3 */
2950 MULTIPLY(tmp3
, FIX(0.642039522)) + /* c7 */
2951 MULTIPLY(tmp4
, FIX(0.221231742)), /* c9 */
2952 CONST_BITS
-PASS1_BITS
);
2953 tmp12
= MULTIPLY(tmp0
- tmp4
, FIX(0.951056516)) - /* (c3+c7)/2 */
2954 MULTIPLY(tmp1
+ tmp3
, FIX(0.587785252)); /* (c1-c9)/2 */
2955 tmp13
= MULTIPLY(tmp10
+ tmp11
, FIX(0.309016994)) + /* (c3-c7)/2 */
2956 (tmp11
<< (CONST_BITS
- 1)) - tmp2
;
2957 dataptr
[3] = (DCTELEM
) DESCALE(tmp12
+ tmp13
, CONST_BITS
-PASS1_BITS
);
2958 dataptr
[7] = (DCTELEM
) DESCALE(tmp12
- tmp13
, CONST_BITS
-PASS1_BITS
);
2960 dataptr
+= DCTSIZE
; /* advance pointer to next row */
2963 /* Pass 2: process columns.
2964 * We remove the PASS1_BITS scaling, but leave the results scaled up
2965 * by an overall factor of 8.
2966 * We must also scale the output by (8/10)*(8/5) = 32/25, which we
2967 * fold into the constant multipliers:
2968 * 5-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/10) * 32/25.
2972 for (ctr
= DCTSIZE
-1; ctr
>= 0; ctr
--) {
2975 tmp0
= dataptr
[DCTSIZE
*0] + dataptr
[DCTSIZE
*4];
2976 tmp1
= dataptr
[DCTSIZE
*1] + dataptr
[DCTSIZE
*3];
2977 tmp2
= dataptr
[DCTSIZE
*2];
2979 tmp10
= tmp0
+ tmp1
;
2980 tmp11
= tmp0
- tmp1
;
2982 tmp0
= dataptr
[DCTSIZE
*0] - dataptr
[DCTSIZE
*4];
2983 tmp1
= dataptr
[DCTSIZE
*1] - dataptr
[DCTSIZE
*3];
2985 dataptr
[DCTSIZE
*0] = (DCTELEM
)
2986 DESCALE(MULTIPLY(tmp10
+ tmp2
, FIX(1.28)), /* 32/25 */
2987 CONST_BITS
+PASS1_BITS
);
2988 tmp11
= MULTIPLY(tmp11
, FIX(1.011928851)); /* (c2+c4)/2 */
2990 tmp10
= MULTIPLY(tmp10
, FIX(0.452548340)); /* (c2-c4)/2 */
2991 dataptr
[DCTSIZE
*2] = (DCTELEM
) DESCALE(tmp11
+ tmp10
, CONST_BITS
+PASS1_BITS
);
2992 dataptr
[DCTSIZE
*4] = (DCTELEM
) DESCALE(tmp11
- tmp10
, CONST_BITS
+PASS1_BITS
);
2996 tmp10
= MULTIPLY(tmp0
+ tmp1
, FIX(1.064004961)); /* c3 */
2998 dataptr
[DCTSIZE
*1] = (DCTELEM
)
2999 DESCALE(tmp10
+ MULTIPLY(tmp0
, FIX(0.657591230)), /* c1-c3 */
3000 CONST_BITS
+PASS1_BITS
);
3001 dataptr
[DCTSIZE
*3] = (DCTELEM
)
3002 DESCALE(tmp10
- MULTIPLY(tmp1
, FIX(2.785601151)), /* c1+c3 */
3003 CONST_BITS
+PASS1_BITS
);
3005 dataptr
++; /* advance pointer to next column */
3011 * Perform the forward DCT on an 8x4 sample block.
3013 * 8-point FDCT in pass 1 (rows), 4-point in pass 2 (columns).
3017 jpeg_fdct_8x4 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
3019 INT32 tmp0
, tmp1
, tmp2
, tmp3
;
3020 INT32 tmp10
, tmp11
, tmp12
, tmp13
;
3027 /* Zero 4 bottom rows of output coefficient block. */
3028 MEMZERO(&data
[DCTSIZE
*4], SIZEOF(DCTELEM
) * DCTSIZE
* 4);
3030 /* Pass 1: process rows.
3031 * Note results are scaled up by sqrt(8) compared to a true DCT;
3032 * furthermore, we scale the results by 2**PASS1_BITS.
3033 * We must also scale the output by 8/4 = 2, which we add here.
3034 * 8-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
3038 for (ctr
= 0; ctr
< 4; ctr
++) {
3039 elemptr
= sample_data
[ctr
] + start_col
;
3041 /* Even part per LL&M figure 1 --- note that published figure is faulty;
3042 * rotator "c1" should be "c6".
3045 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[7]);
3046 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[6]);
3047 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[5]);
3048 tmp3
= GETJSAMPLE(elemptr
[3]) + GETJSAMPLE(elemptr
[4]);
3050 tmp10
= tmp0
+ tmp3
;
3051 tmp12
= tmp0
- tmp3
;
3052 tmp11
= tmp1
+ tmp2
;
3053 tmp13
= tmp1
- tmp2
;
3055 tmp0
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[7]);
3056 tmp1
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[6]);
3057 tmp2
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[5]);
3058 tmp3
= GETJSAMPLE(elemptr
[3]) - GETJSAMPLE(elemptr
[4]);
3060 /* Apply unsigned->signed conversion */
3061 dataptr
[0] = (DCTELEM
)
3062 ((tmp10
+ tmp11
- 8 * CENTERJSAMPLE
) << (PASS1_BITS
+1));
3063 dataptr
[4] = (DCTELEM
) ((tmp10
- tmp11
) << (PASS1_BITS
+1));
3065 z1
= MULTIPLY(tmp12
+ tmp13
, FIX_0_541196100
); /* c6 */
3066 /* Add fudge factor here for final descale. */
3067 z1
+= ONE
<< (CONST_BITS
-PASS1_BITS
-2);
3069 dataptr
[2] = (DCTELEM
)
3070 RIGHT_SHIFT(z1
+ MULTIPLY(tmp12
, FIX_0_765366865
), /* c2-c6 */
3071 CONST_BITS
-PASS1_BITS
-1);
3072 dataptr
[6] = (DCTELEM
)
3073 RIGHT_SHIFT(z1
- MULTIPLY(tmp13
, FIX_1_847759065
), /* c2+c6 */
3074 CONST_BITS
-PASS1_BITS
-1);
3076 /* Odd part per figure 8 --- note paper omits factor of sqrt(2).
3077 * i0..i3 in the paper are tmp0..tmp3 here.
3080 tmp12
= tmp0
+ tmp2
;
3081 tmp13
= tmp1
+ tmp3
;
3083 z1
= MULTIPLY(tmp12
+ tmp13
, FIX_1_175875602
); /* c3 */
3084 /* Add fudge factor here for final descale. */
3085 z1
+= ONE
<< (CONST_BITS
-PASS1_BITS
-2);
3087 tmp12
= MULTIPLY(tmp12
, - FIX_0_390180644
); /* -c3+c5 */
3088 tmp13
= MULTIPLY(tmp13
, - FIX_1_961570560
); /* -c3-c5 */
3092 z1
= MULTIPLY(tmp0
+ tmp3
, - FIX_0_899976223
); /* -c3+c7 */
3093 tmp0
= MULTIPLY(tmp0
, FIX_1_501321110
); /* c1+c3-c5-c7 */
3094 tmp3
= MULTIPLY(tmp3
, FIX_0_298631336
); /* -c1+c3+c5-c7 */
3098 z1
= MULTIPLY(tmp1
+ tmp2
, - FIX_2_562915447
); /* -c1-c3 */
3099 tmp1
= MULTIPLY(tmp1
, FIX_3_072711026
); /* c1+c3+c5-c7 */
3100 tmp2
= MULTIPLY(tmp2
, FIX_2_053119869
); /* c1+c3-c5+c7 */
3104 dataptr
[1] = (DCTELEM
) RIGHT_SHIFT(tmp0
, CONST_BITS
-PASS1_BITS
-1);
3105 dataptr
[3] = (DCTELEM
) RIGHT_SHIFT(tmp1
, CONST_BITS
-PASS1_BITS
-1);
3106 dataptr
[5] = (DCTELEM
) RIGHT_SHIFT(tmp2
, CONST_BITS
-PASS1_BITS
-1);
3107 dataptr
[7] = (DCTELEM
) RIGHT_SHIFT(tmp3
, CONST_BITS
-PASS1_BITS
-1);
3109 dataptr
+= DCTSIZE
; /* advance pointer to next row */
3112 /* Pass 2: process columns.
3113 * We remove the PASS1_BITS scaling, but leave the results scaled up
3114 * by an overall factor of 8.
3115 * 4-point FDCT kernel,
3116 * cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point FDCT].
3120 for (ctr
= DCTSIZE
-1; ctr
>= 0; ctr
--) {
3123 /* Add fudge factor here for final descale. */
3124 tmp0
= dataptr
[DCTSIZE
*0] + dataptr
[DCTSIZE
*3] + (ONE
<< (PASS1_BITS
-1));
3125 tmp1
= dataptr
[DCTSIZE
*1] + dataptr
[DCTSIZE
*2];
3127 tmp10
= dataptr
[DCTSIZE
*0] - dataptr
[DCTSIZE
*3];
3128 tmp11
= dataptr
[DCTSIZE
*1] - dataptr
[DCTSIZE
*2];
3130 dataptr
[DCTSIZE
*0] = (DCTELEM
) RIGHT_SHIFT(tmp0
+ tmp1
, PASS1_BITS
);
3131 dataptr
[DCTSIZE
*2] = (DCTELEM
) RIGHT_SHIFT(tmp0
- tmp1
, PASS1_BITS
);
3135 tmp0
= MULTIPLY(tmp10
+ tmp11
, FIX_0_541196100
); /* c6 */
3136 /* Add fudge factor here for final descale. */
3137 tmp0
+= ONE
<< (CONST_BITS
+PASS1_BITS
-1);
3139 dataptr
[DCTSIZE
*1] = (DCTELEM
)
3140 RIGHT_SHIFT(tmp0
+ MULTIPLY(tmp10
, FIX_0_765366865
), /* c2-c6 */
3141 CONST_BITS
+PASS1_BITS
);
3142 dataptr
[DCTSIZE
*3] = (DCTELEM
)
3143 RIGHT_SHIFT(tmp0
- MULTIPLY(tmp11
, FIX_1_847759065
), /* c2+c6 */
3144 CONST_BITS
+PASS1_BITS
);
3146 dataptr
++; /* advance pointer to next column */
3152 * Perform the forward DCT on a 6x3 sample block.
3154 * 6-point FDCT in pass 1 (rows), 3-point in pass 2 (columns).
3158 jpeg_fdct_6x3 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
3160 INT32 tmp0
, tmp1
, tmp2
;
3161 INT32 tmp10
, tmp11
, tmp12
;
3167 /* Pre-zero output coefficient block. */
3168 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
3170 /* Pass 1: process rows.
3171 * Note results are scaled up by sqrt(8) compared to a true DCT;
3172 * furthermore, we scale the results by 2**PASS1_BITS.
3173 * We scale the results further by 2 as part of output adaption
3174 * scaling for different DCT size.
3175 * 6-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/12).
3179 for (ctr
= 0; ctr
< 3; ctr
++) {
3180 elemptr
= sample_data
[ctr
] + start_col
;
3184 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[5]);
3185 tmp11
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[4]);
3186 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[3]);
3188 tmp10
= tmp0
+ tmp2
;
3189 tmp12
= tmp0
- tmp2
;
3191 tmp0
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[5]);
3192 tmp1
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[4]);
3193 tmp2
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[3]);
3195 /* Apply unsigned->signed conversion */
3196 dataptr
[0] = (DCTELEM
)
3197 ((tmp10
+ tmp11
- 6 * CENTERJSAMPLE
) << (PASS1_BITS
+1));
3198 dataptr
[2] = (DCTELEM
)
3199 DESCALE(MULTIPLY(tmp12
, FIX(1.224744871)), /* c2 */
3200 CONST_BITS
-PASS1_BITS
-1);
3201 dataptr
[4] = (DCTELEM
)
3202 DESCALE(MULTIPLY(tmp10
- tmp11
- tmp11
, FIX(0.707106781)), /* c4 */
3203 CONST_BITS
-PASS1_BITS
-1);
3207 tmp10
= DESCALE(MULTIPLY(tmp0
+ tmp2
, FIX(0.366025404)), /* c5 */
3208 CONST_BITS
-PASS1_BITS
-1);
3210 dataptr
[1] = (DCTELEM
) (tmp10
+ ((tmp0
+ tmp1
) << (PASS1_BITS
+1)));
3211 dataptr
[3] = (DCTELEM
) ((tmp0
- tmp1
- tmp2
) << (PASS1_BITS
+1));
3212 dataptr
[5] = (DCTELEM
) (tmp10
+ ((tmp2
- tmp1
) << (PASS1_BITS
+1)));
3214 dataptr
+= DCTSIZE
; /* advance pointer to next row */
3217 /* Pass 2: process columns.
3218 * We remove the PASS1_BITS scaling, but leave the results scaled up
3219 * by an overall factor of 8.
3220 * We must also scale the output by (8/6)*(8/3) = 32/9, which we partially
3221 * fold into the constant multipliers (other part was done in pass 1):
3222 * 3-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/6) * 16/9.
3226 for (ctr
= 0; ctr
< 6; ctr
++) {
3229 tmp0
= dataptr
[DCTSIZE
*0] + dataptr
[DCTSIZE
*2];
3230 tmp1
= dataptr
[DCTSIZE
*1];
3232 tmp2
= dataptr
[DCTSIZE
*0] - dataptr
[DCTSIZE
*2];
3234 dataptr
[DCTSIZE
*0] = (DCTELEM
)
3235 DESCALE(MULTIPLY(tmp0
+ tmp1
, FIX(1.777777778)), /* 16/9 */
3236 CONST_BITS
+PASS1_BITS
);
3237 dataptr
[DCTSIZE
*2] = (DCTELEM
)
3238 DESCALE(MULTIPLY(tmp0
- tmp1
- tmp1
, FIX(1.257078722)), /* c2 */
3239 CONST_BITS
+PASS1_BITS
);
3243 dataptr
[DCTSIZE
*1] = (DCTELEM
)
3244 DESCALE(MULTIPLY(tmp2
, FIX(2.177324216)), /* c1 */
3245 CONST_BITS
+PASS1_BITS
);
3247 dataptr
++; /* advance pointer to next column */
3253 * Perform the forward DCT on a 4x2 sample block.
3255 * 4-point FDCT in pass 1 (rows), 2-point in pass 2 (columns).
3259 jpeg_fdct_4x2 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
3268 /* Pre-zero output coefficient block. */
3269 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
3271 /* Pass 1: process rows.
3272 * Note results are scaled up by sqrt(8) compared to a true DCT;
3273 * furthermore, we scale the results by 2**PASS1_BITS.
3274 * We must also scale the output by (8/4)*(8/2) = 2**3, which we add here.
3275 * 4-point FDCT kernel,
3276 * cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point FDCT].
3280 for (ctr
= 0; ctr
< 2; ctr
++) {
3281 elemptr
= sample_data
[ctr
] + start_col
;
3285 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[3]);
3286 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[2]);
3288 tmp10
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[3]);
3289 tmp11
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[2]);
3291 /* Apply unsigned->signed conversion */
3292 dataptr
[0] = (DCTELEM
)
3293 ((tmp0
+ tmp1
- 4 * CENTERJSAMPLE
) << (PASS1_BITS
+3));
3294 dataptr
[2] = (DCTELEM
) ((tmp0
- tmp1
) << (PASS1_BITS
+3));
3298 tmp0
= MULTIPLY(tmp10
+ tmp11
, FIX_0_541196100
); /* c6 */
3299 /* Add fudge factor here for final descale. */
3300 tmp0
+= ONE
<< (CONST_BITS
-PASS1_BITS
-4);
3302 dataptr
[1] = (DCTELEM
)
3303 RIGHT_SHIFT(tmp0
+ MULTIPLY(tmp10
, FIX_0_765366865
), /* c2-c6 */
3304 CONST_BITS
-PASS1_BITS
-3);
3305 dataptr
[3] = (DCTELEM
)
3306 RIGHT_SHIFT(tmp0
- MULTIPLY(tmp11
, FIX_1_847759065
), /* c2+c6 */
3307 CONST_BITS
-PASS1_BITS
-3);
3309 dataptr
+= DCTSIZE
; /* advance pointer to next row */
3312 /* Pass 2: process columns.
3313 * We remove the PASS1_BITS scaling, but leave the results scaled up
3314 * by an overall factor of 8.
3318 for (ctr
= 0; ctr
< 4; ctr
++) {
3321 /* Add fudge factor here for final descale. */
3322 tmp0
= dataptr
[DCTSIZE
*0] + (ONE
<< (PASS1_BITS
-1));
3323 tmp1
= dataptr
[DCTSIZE
*1];
3325 dataptr
[DCTSIZE
*0] = (DCTELEM
) RIGHT_SHIFT(tmp0
+ tmp1
, PASS1_BITS
);
3329 dataptr
[DCTSIZE
*1] = (DCTELEM
) RIGHT_SHIFT(tmp0
- tmp1
, PASS1_BITS
);
3331 dataptr
++; /* advance pointer to next column */
3337 * Perform the forward DCT on a 2x1 sample block.
3339 * 2-point FDCT in pass 1 (rows), 1-point in pass 2 (columns).
3343 jpeg_fdct_2x1 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
3348 /* Pre-zero output coefficient block. */
3349 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
3351 elemptr
= sample_data
[0] + start_col
;
3353 tmp0
= GETJSAMPLE(elemptr
[0]);
3354 tmp1
= GETJSAMPLE(elemptr
[1]);
3356 /* We leave the results scaled up by an overall factor of 8.
3357 * We must also scale the output by (8/2)*(8/1) = 2**5.
3362 /* Apply unsigned->signed conversion */
3363 data
[0] = (DCTELEM
) ((tmp0
+ tmp1
- 2 * CENTERJSAMPLE
) << 5);
3367 data
[1] = (DCTELEM
) ((tmp0
- tmp1
) << 5);
3372 * Perform the forward DCT on an 8x16 sample block.
3374 * 8-point FDCT in pass 1 (rows), 16-point in pass 2 (columns).
3378 jpeg_fdct_8x16 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
3380 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
, tmp5
, tmp6
, tmp7
;
3381 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
, tmp15
, tmp16
, tmp17
;
3383 DCTELEM workspace
[DCTSIZE2
];
3390 /* Pass 1: process rows.
3391 * Note results are scaled up by sqrt(8) compared to a true DCT;
3392 * furthermore, we scale the results by 2**PASS1_BITS.
3393 * 8-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
3399 elemptr
= sample_data
[ctr
] + start_col
;
3401 /* Even part per LL&M figure 1 --- note that published figure is faulty;
3402 * rotator "c1" should be "c6".
3405 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[7]);
3406 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[6]);
3407 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[5]);
3408 tmp3
= GETJSAMPLE(elemptr
[3]) + GETJSAMPLE(elemptr
[4]);
3410 tmp10
= tmp0
+ tmp3
;
3411 tmp12
= tmp0
- tmp3
;
3412 tmp11
= tmp1
+ tmp2
;
3413 tmp13
= tmp1
- tmp2
;
3415 tmp0
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[7]);
3416 tmp1
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[6]);
3417 tmp2
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[5]);
3418 tmp3
= GETJSAMPLE(elemptr
[3]) - GETJSAMPLE(elemptr
[4]);
3420 /* Apply unsigned->signed conversion */
3421 dataptr
[0] = (DCTELEM
) ((tmp10
+ tmp11
- 8 * CENTERJSAMPLE
) << PASS1_BITS
);
3422 dataptr
[4] = (DCTELEM
) ((tmp10
- tmp11
) << PASS1_BITS
);
3424 z1
= MULTIPLY(tmp12
+ tmp13
, FIX_0_541196100
); /* c6 */
3425 dataptr
[2] = (DCTELEM
)
3426 DESCALE(z1
+ MULTIPLY(tmp12
, FIX_0_765366865
), /* c2-c6 */
3427 CONST_BITS
-PASS1_BITS
);
3428 dataptr
[6] = (DCTELEM
)
3429 DESCALE(z1
- MULTIPLY(tmp13
, FIX_1_847759065
), /* c2+c6 */
3430 CONST_BITS
-PASS1_BITS
);
3432 /* Odd part per figure 8 --- note paper omits factor of sqrt(2).
3433 * i0..i3 in the paper are tmp0..tmp3 here.
3436 tmp12
= tmp0
+ tmp2
;
3437 tmp13
= tmp1
+ tmp3
;
3439 z1
= MULTIPLY(tmp12
+ tmp13
, FIX_1_175875602
); /* c3 */
3440 tmp12
= MULTIPLY(tmp12
, - FIX_0_390180644
); /* -c3+c5 */
3441 tmp13
= MULTIPLY(tmp13
, - FIX_1_961570560
); /* -c3-c5 */
3445 z1
= MULTIPLY(tmp0
+ tmp3
, - FIX_0_899976223
); /* -c3+c7 */
3446 tmp0
= MULTIPLY(tmp0
, FIX_1_501321110
); /* c1+c3-c5-c7 */
3447 tmp3
= MULTIPLY(tmp3
, FIX_0_298631336
); /* -c1+c3+c5-c7 */
3451 z1
= MULTIPLY(tmp1
+ tmp2
, - FIX_2_562915447
); /* -c1-c3 */
3452 tmp1
= MULTIPLY(tmp1
, FIX_3_072711026
); /* c1+c3+c5-c7 */
3453 tmp2
= MULTIPLY(tmp2
, FIX_2_053119869
); /* c1+c3-c5+c7 */
3457 dataptr
[1] = (DCTELEM
) DESCALE(tmp0
, CONST_BITS
-PASS1_BITS
);
3458 dataptr
[3] = (DCTELEM
) DESCALE(tmp1
, CONST_BITS
-PASS1_BITS
);
3459 dataptr
[5] = (DCTELEM
) DESCALE(tmp2
, CONST_BITS
-PASS1_BITS
);
3460 dataptr
[7] = (DCTELEM
) DESCALE(tmp3
, CONST_BITS
-PASS1_BITS
);
3464 if (ctr
!= DCTSIZE
) {
3465 if (ctr
== DCTSIZE
* 2)
3467 dataptr
+= DCTSIZE
; /* advance pointer to next row */
3469 dataptr
= workspace
; /* switch pointer to extended workspace */
3472 /* Pass 2: process columns.
3473 * We remove the PASS1_BITS scaling, but leave the results scaled up
3474 * by an overall factor of 8.
3475 * We must also scale the output by 8/16 = 1/2.
3476 * 16-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/32).
3481 for (ctr
= DCTSIZE
-1; ctr
>= 0; ctr
--) {
3484 tmp0
= dataptr
[DCTSIZE
*0] + wsptr
[DCTSIZE
*7];
3485 tmp1
= dataptr
[DCTSIZE
*1] + wsptr
[DCTSIZE
*6];
3486 tmp2
= dataptr
[DCTSIZE
*2] + wsptr
[DCTSIZE
*5];
3487 tmp3
= dataptr
[DCTSIZE
*3] + wsptr
[DCTSIZE
*4];
3488 tmp4
= dataptr
[DCTSIZE
*4] + wsptr
[DCTSIZE
*3];
3489 tmp5
= dataptr
[DCTSIZE
*5] + wsptr
[DCTSIZE
*2];
3490 tmp6
= dataptr
[DCTSIZE
*6] + wsptr
[DCTSIZE
*1];
3491 tmp7
= dataptr
[DCTSIZE
*7] + wsptr
[DCTSIZE
*0];
3493 tmp10
= tmp0
+ tmp7
;
3494 tmp14
= tmp0
- tmp7
;
3495 tmp11
= tmp1
+ tmp6
;
3496 tmp15
= tmp1
- tmp6
;
3497 tmp12
= tmp2
+ tmp5
;
3498 tmp16
= tmp2
- tmp5
;
3499 tmp13
= tmp3
+ tmp4
;
3500 tmp17
= tmp3
- tmp4
;
3502 tmp0
= dataptr
[DCTSIZE
*0] - wsptr
[DCTSIZE
*7];
3503 tmp1
= dataptr
[DCTSIZE
*1] - wsptr
[DCTSIZE
*6];
3504 tmp2
= dataptr
[DCTSIZE
*2] - wsptr
[DCTSIZE
*5];
3505 tmp3
= dataptr
[DCTSIZE
*3] - wsptr
[DCTSIZE
*4];
3506 tmp4
= dataptr
[DCTSIZE
*4] - wsptr
[DCTSIZE
*3];
3507 tmp5
= dataptr
[DCTSIZE
*5] - wsptr
[DCTSIZE
*2];
3508 tmp6
= dataptr
[DCTSIZE
*6] - wsptr
[DCTSIZE
*1];
3509 tmp7
= dataptr
[DCTSIZE
*7] - wsptr
[DCTSIZE
*0];
3511 dataptr
[DCTSIZE
*0] = (DCTELEM
)
3512 DESCALE(tmp10
+ tmp11
+ tmp12
+ tmp13
, PASS1_BITS
+1);
3513 dataptr
[DCTSIZE
*4] = (DCTELEM
)
3514 DESCALE(MULTIPLY(tmp10
- tmp13
, FIX(1.306562965)) + /* c4[16] = c2[8] */
3515 MULTIPLY(tmp11
- tmp12
, FIX_0_541196100
), /* c12[16] = c6[8] */
3516 CONST_BITS
+PASS1_BITS
+1);
3518 tmp10
= MULTIPLY(tmp17
- tmp15
, FIX(0.275899379)) + /* c14[16] = c7[8] */
3519 MULTIPLY(tmp14
- tmp16
, FIX(1.387039845)); /* c2[16] = c1[8] */
3521 dataptr
[DCTSIZE
*2] = (DCTELEM
)
3522 DESCALE(tmp10
+ MULTIPLY(tmp15
, FIX(1.451774982)) /* c6+c14 */
3523 + MULTIPLY(tmp16
, FIX(2.172734804)), /* c2+c10 */
3524 CONST_BITS
+PASS1_BITS
+1);
3525 dataptr
[DCTSIZE
*6] = (DCTELEM
)
3526 DESCALE(tmp10
- MULTIPLY(tmp14
, FIX(0.211164243)) /* c2-c6 */
3527 - MULTIPLY(tmp17
, FIX(1.061594338)), /* c10+c14 */
3528 CONST_BITS
+PASS1_BITS
+1);
3532 tmp11
= MULTIPLY(tmp0
+ tmp1
, FIX(1.353318001)) + /* c3 */
3533 MULTIPLY(tmp6
- tmp7
, FIX(0.410524528)); /* c13 */
3534 tmp12
= MULTIPLY(tmp0
+ tmp2
, FIX(1.247225013)) + /* c5 */
3535 MULTIPLY(tmp5
+ tmp7
, FIX(0.666655658)); /* c11 */
3536 tmp13
= MULTIPLY(tmp0
+ tmp3
, FIX(1.093201867)) + /* c7 */
3537 MULTIPLY(tmp4
- tmp7
, FIX(0.897167586)); /* c9 */
3538 tmp14
= MULTIPLY(tmp1
+ tmp2
, FIX(0.138617169)) + /* c15 */
3539 MULTIPLY(tmp6
- tmp5
, FIX(1.407403738)); /* c1 */
3540 tmp15
= MULTIPLY(tmp1
+ tmp3
, - FIX(0.666655658)) + /* -c11 */
3541 MULTIPLY(tmp4
+ tmp6
, - FIX(1.247225013)); /* -c5 */
3542 tmp16
= MULTIPLY(tmp2
+ tmp3
, - FIX(1.353318001)) + /* -c3 */
3543 MULTIPLY(tmp5
- tmp4
, FIX(0.410524528)); /* c13 */
3544 tmp10
= tmp11
+ tmp12
+ tmp13
-
3545 MULTIPLY(tmp0
, FIX(2.286341144)) + /* c7+c5+c3-c1 */
3546 MULTIPLY(tmp7
, FIX(0.779653625)); /* c15+c13-c11+c9 */
3547 tmp11
+= tmp14
+ tmp15
+ MULTIPLY(tmp1
, FIX(0.071888074)) /* c9-c3-c15+c11 */
3548 - MULTIPLY(tmp6
, FIX(1.663905119)); /* c7+c13+c1-c5 */
3549 tmp12
+= tmp14
+ tmp16
- MULTIPLY(tmp2
, FIX(1.125726048)) /* c7+c5+c15-c3 */
3550 + MULTIPLY(tmp5
, FIX(1.227391138)); /* c9-c11+c1-c13 */
3551 tmp13
+= tmp15
+ tmp16
+ MULTIPLY(tmp3
, FIX(1.065388962)) /* c15+c3+c11-c7 */
3552 + MULTIPLY(tmp4
, FIX(2.167985692)); /* c1+c13+c5-c9 */
3554 dataptr
[DCTSIZE
*1] = (DCTELEM
) DESCALE(tmp10
, CONST_BITS
+PASS1_BITS
+1);
3555 dataptr
[DCTSIZE
*3] = (DCTELEM
) DESCALE(tmp11
, CONST_BITS
+PASS1_BITS
+1);
3556 dataptr
[DCTSIZE
*5] = (DCTELEM
) DESCALE(tmp12
, CONST_BITS
+PASS1_BITS
+1);
3557 dataptr
[DCTSIZE
*7] = (DCTELEM
) DESCALE(tmp13
, CONST_BITS
+PASS1_BITS
+1);
3559 dataptr
++; /* advance pointer to next column */
3560 wsptr
++; /* advance pointer to next column */
3566 * Perform the forward DCT on a 7x14 sample block.
3568 * 7-point FDCT in pass 1 (rows), 14-point in pass 2 (columns).
3572 jpeg_fdct_7x14 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
3574 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
, tmp5
, tmp6
;
3575 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
, tmp15
, tmp16
;
3577 DCTELEM workspace
[8*6];
3584 /* Pre-zero output coefficient block. */
3585 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
3587 /* Pass 1: process rows.
3588 * Note results are scaled up by sqrt(8) compared to a true DCT;
3589 * furthermore, we scale the results by 2**PASS1_BITS.
3590 * 7-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/14).
3596 elemptr
= sample_data
[ctr
] + start_col
;
3600 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[6]);
3601 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[5]);
3602 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[4]);
3603 tmp3
= GETJSAMPLE(elemptr
[3]);
3605 tmp10
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[6]);
3606 tmp11
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[5]);
3607 tmp12
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[4]);
3610 /* Apply unsigned->signed conversion */
3611 dataptr
[0] = (DCTELEM
)
3612 ((z1
+ tmp1
+ tmp3
- 7 * CENTERJSAMPLE
) << PASS1_BITS
);
3616 z1
= MULTIPLY(z1
, FIX(0.353553391)); /* (c2+c6-c4)/2 */
3617 z2
= MULTIPLY(tmp0
- tmp2
, FIX(0.920609002)); /* (c2+c4-c6)/2 */
3618 z3
= MULTIPLY(tmp1
- tmp2
, FIX(0.314692123)); /* c6 */
3619 dataptr
[2] = (DCTELEM
) DESCALE(z1
+ z2
+ z3
, CONST_BITS
-PASS1_BITS
);
3621 z2
= MULTIPLY(tmp0
- tmp1
, FIX(0.881747734)); /* c4 */
3622 dataptr
[4] = (DCTELEM
)
3623 DESCALE(z2
+ z3
- MULTIPLY(tmp1
- tmp3
, FIX(0.707106781)), /* c2+c6-c4 */
3624 CONST_BITS
-PASS1_BITS
);
3625 dataptr
[6] = (DCTELEM
) DESCALE(z1
+ z2
, CONST_BITS
-PASS1_BITS
);
3629 tmp1
= MULTIPLY(tmp10
+ tmp11
, FIX(0.935414347)); /* (c3+c1-c5)/2 */
3630 tmp2
= MULTIPLY(tmp10
- tmp11
, FIX(0.170262339)); /* (c3+c5-c1)/2 */
3633 tmp2
= MULTIPLY(tmp11
+ tmp12
, - FIX(1.378756276)); /* -c1 */
3635 tmp3
= MULTIPLY(tmp10
+ tmp12
, FIX(0.613604268)); /* c5 */
3637 tmp2
+= tmp3
+ MULTIPLY(tmp12
, FIX(1.870828693)); /* c3+c1-c5 */
3639 dataptr
[1] = (DCTELEM
) DESCALE(tmp0
, CONST_BITS
-PASS1_BITS
);
3640 dataptr
[3] = (DCTELEM
) DESCALE(tmp1
, CONST_BITS
-PASS1_BITS
);
3641 dataptr
[5] = (DCTELEM
) DESCALE(tmp2
, CONST_BITS
-PASS1_BITS
);
3645 if (ctr
!= DCTSIZE
) {
3648 dataptr
+= DCTSIZE
; /* advance pointer to next row */
3650 dataptr
= workspace
; /* switch pointer to extended workspace */
3653 /* Pass 2: process columns.
3654 * We remove the PASS1_BITS scaling, but leave the results scaled up
3655 * by an overall factor of 8.
3656 * We must also scale the output by (8/7)*(8/14) = 32/49, which we
3657 * fold into the constant multipliers:
3658 * 14-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/28) * 32/49.
3663 for (ctr
= 0; ctr
< 7; ctr
++) {
3666 tmp0
= dataptr
[DCTSIZE
*0] + wsptr
[DCTSIZE
*5];
3667 tmp1
= dataptr
[DCTSIZE
*1] + wsptr
[DCTSIZE
*4];
3668 tmp2
= dataptr
[DCTSIZE
*2] + wsptr
[DCTSIZE
*3];
3669 tmp13
= dataptr
[DCTSIZE
*3] + wsptr
[DCTSIZE
*2];
3670 tmp4
= dataptr
[DCTSIZE
*4] + wsptr
[DCTSIZE
*1];
3671 tmp5
= dataptr
[DCTSIZE
*5] + wsptr
[DCTSIZE
*0];
3672 tmp6
= dataptr
[DCTSIZE
*6] + dataptr
[DCTSIZE
*7];
3674 tmp10
= tmp0
+ tmp6
;
3675 tmp14
= tmp0
- tmp6
;
3676 tmp11
= tmp1
+ tmp5
;
3677 tmp15
= tmp1
- tmp5
;
3678 tmp12
= tmp2
+ tmp4
;
3679 tmp16
= tmp2
- tmp4
;
3681 tmp0
= dataptr
[DCTSIZE
*0] - wsptr
[DCTSIZE
*5];
3682 tmp1
= dataptr
[DCTSIZE
*1] - wsptr
[DCTSIZE
*4];
3683 tmp2
= dataptr
[DCTSIZE
*2] - wsptr
[DCTSIZE
*3];
3684 tmp3
= dataptr
[DCTSIZE
*3] - wsptr
[DCTSIZE
*2];
3685 tmp4
= dataptr
[DCTSIZE
*4] - wsptr
[DCTSIZE
*1];
3686 tmp5
= dataptr
[DCTSIZE
*5] - wsptr
[DCTSIZE
*0];
3687 tmp6
= dataptr
[DCTSIZE
*6] - dataptr
[DCTSIZE
*7];
3689 dataptr
[DCTSIZE
*0] = (DCTELEM
)
3690 DESCALE(MULTIPLY(tmp10
+ tmp11
+ tmp12
+ tmp13
,
3691 FIX(0.653061224)), /* 32/49 */
3692 CONST_BITS
+PASS1_BITS
);
3694 dataptr
[DCTSIZE
*4] = (DCTELEM
)
3695 DESCALE(MULTIPLY(tmp10
- tmp13
, FIX(0.832106052)) + /* c4 */
3696 MULTIPLY(tmp11
- tmp13
, FIX(0.205513223)) - /* c12 */
3697 MULTIPLY(tmp12
- tmp13
, FIX(0.575835255)), /* c8 */
3698 CONST_BITS
+PASS1_BITS
);
3700 tmp10
= MULTIPLY(tmp14
+ tmp15
, FIX(0.722074570)); /* c6 */
3702 dataptr
[DCTSIZE
*2] = (DCTELEM
)
3703 DESCALE(tmp10
+ MULTIPLY(tmp14
, FIX(0.178337691)) /* c2-c6 */
3704 + MULTIPLY(tmp16
, FIX(0.400721155)), /* c10 */
3705 CONST_BITS
+PASS1_BITS
);
3706 dataptr
[DCTSIZE
*6] = (DCTELEM
)
3707 DESCALE(tmp10
- MULTIPLY(tmp15
, FIX(1.122795725)) /* c6+c10 */
3708 - MULTIPLY(tmp16
, FIX(0.900412262)), /* c2 */
3709 CONST_BITS
+PASS1_BITS
);
3713 tmp10
= tmp1
+ tmp2
;
3714 tmp11
= tmp5
- tmp4
;
3715 dataptr
[DCTSIZE
*7] = (DCTELEM
)
3716 DESCALE(MULTIPLY(tmp0
- tmp10
+ tmp3
- tmp11
- tmp6
,
3717 FIX(0.653061224)), /* 32/49 */
3718 CONST_BITS
+PASS1_BITS
);
3719 tmp3
= MULTIPLY(tmp3
, FIX(0.653061224)); /* 32/49 */
3720 tmp10
= MULTIPLY(tmp10
, - FIX(0.103406812)); /* -c13 */
3721 tmp11
= MULTIPLY(tmp11
, FIX(0.917760839)); /* c1 */
3722 tmp10
+= tmp11
- tmp3
;
3723 tmp11
= MULTIPLY(tmp0
+ tmp2
, FIX(0.782007410)) + /* c5 */
3724 MULTIPLY(tmp4
+ tmp6
, FIX(0.491367823)); /* c9 */
3725 dataptr
[DCTSIZE
*5] = (DCTELEM
)
3726 DESCALE(tmp10
+ tmp11
- MULTIPLY(tmp2
, FIX(1.550341076)) /* c3+c5-c13 */
3727 + MULTIPLY(tmp4
, FIX(0.731428202)), /* c1+c11-c9 */
3728 CONST_BITS
+PASS1_BITS
);
3729 tmp12
= MULTIPLY(tmp0
+ tmp1
, FIX(0.871740478)) + /* c3 */
3730 MULTIPLY(tmp5
- tmp6
, FIX(0.305035186)); /* c11 */
3731 dataptr
[DCTSIZE
*3] = (DCTELEM
)
3732 DESCALE(tmp10
+ tmp12
- MULTIPLY(tmp1
, FIX(0.276965844)) /* c3-c9-c13 */
3733 - MULTIPLY(tmp5
, FIX(2.004803435)), /* c1+c5+c11 */
3734 CONST_BITS
+PASS1_BITS
);
3735 dataptr
[DCTSIZE
*1] = (DCTELEM
)
3736 DESCALE(tmp11
+ tmp12
+ tmp3
3737 - MULTIPLY(tmp0
, FIX(0.735987049)) /* c3+c5-c1 */
3738 - MULTIPLY(tmp6
, FIX(0.082925825)), /* c9-c11-c13 */
3739 CONST_BITS
+PASS1_BITS
);
3741 dataptr
++; /* advance pointer to next column */
3742 wsptr
++; /* advance pointer to next column */
3748 * Perform the forward DCT on a 6x12 sample block.
3750 * 6-point FDCT in pass 1 (rows), 12-point in pass 2 (columns).
3754 jpeg_fdct_6x12 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
3756 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
, tmp5
;
3757 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
, tmp15
;
3758 DCTELEM workspace
[8*4];
3765 /* Pre-zero output coefficient block. */
3766 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
3768 /* Pass 1: process rows.
3769 * Note results are scaled up by sqrt(8) compared to a true DCT;
3770 * furthermore, we scale the results by 2**PASS1_BITS.
3771 * 6-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/12).
3777 elemptr
= sample_data
[ctr
] + start_col
;
3781 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[5]);
3782 tmp11
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[4]);
3783 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[3]);
3785 tmp10
= tmp0
+ tmp2
;
3786 tmp12
= tmp0
- tmp2
;
3788 tmp0
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[5]);
3789 tmp1
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[4]);
3790 tmp2
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[3]);
3792 /* Apply unsigned->signed conversion */
3793 dataptr
[0] = (DCTELEM
)
3794 ((tmp10
+ tmp11
- 6 * CENTERJSAMPLE
) << PASS1_BITS
);
3795 dataptr
[2] = (DCTELEM
)
3796 DESCALE(MULTIPLY(tmp12
, FIX(1.224744871)), /* c2 */
3797 CONST_BITS
-PASS1_BITS
);
3798 dataptr
[4] = (DCTELEM
)
3799 DESCALE(MULTIPLY(tmp10
- tmp11
- tmp11
, FIX(0.707106781)), /* c4 */
3800 CONST_BITS
-PASS1_BITS
);
3804 tmp10
= DESCALE(MULTIPLY(tmp0
+ tmp2
, FIX(0.366025404)), /* c5 */
3805 CONST_BITS
-PASS1_BITS
);
3807 dataptr
[1] = (DCTELEM
) (tmp10
+ ((tmp0
+ tmp1
) << PASS1_BITS
));
3808 dataptr
[3] = (DCTELEM
) ((tmp0
- tmp1
- tmp2
) << PASS1_BITS
);
3809 dataptr
[5] = (DCTELEM
) (tmp10
+ ((tmp2
- tmp1
) << PASS1_BITS
));
3813 if (ctr
!= DCTSIZE
) {
3816 dataptr
+= DCTSIZE
; /* advance pointer to next row */
3818 dataptr
= workspace
; /* switch pointer to extended workspace */
3821 /* Pass 2: process columns.
3822 * We remove the PASS1_BITS scaling, but leave the results scaled up
3823 * by an overall factor of 8.
3824 * We must also scale the output by (8/6)*(8/12) = 8/9, which we
3825 * fold into the constant multipliers:
3826 * 12-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/24) * 8/9.
3831 for (ctr
= 0; ctr
< 6; ctr
++) {
3834 tmp0
= dataptr
[DCTSIZE
*0] + wsptr
[DCTSIZE
*3];
3835 tmp1
= dataptr
[DCTSIZE
*1] + wsptr
[DCTSIZE
*2];
3836 tmp2
= dataptr
[DCTSIZE
*2] + wsptr
[DCTSIZE
*1];
3837 tmp3
= dataptr
[DCTSIZE
*3] + wsptr
[DCTSIZE
*0];
3838 tmp4
= dataptr
[DCTSIZE
*4] + dataptr
[DCTSIZE
*7];
3839 tmp5
= dataptr
[DCTSIZE
*5] + dataptr
[DCTSIZE
*6];
3841 tmp10
= tmp0
+ tmp5
;
3842 tmp13
= tmp0
- tmp5
;
3843 tmp11
= tmp1
+ tmp4
;
3844 tmp14
= tmp1
- tmp4
;
3845 tmp12
= tmp2
+ tmp3
;
3846 tmp15
= tmp2
- tmp3
;
3848 tmp0
= dataptr
[DCTSIZE
*0] - wsptr
[DCTSIZE
*3];
3849 tmp1
= dataptr
[DCTSIZE
*1] - wsptr
[DCTSIZE
*2];
3850 tmp2
= dataptr
[DCTSIZE
*2] - wsptr
[DCTSIZE
*1];
3851 tmp3
= dataptr
[DCTSIZE
*3] - wsptr
[DCTSIZE
*0];
3852 tmp4
= dataptr
[DCTSIZE
*4] - dataptr
[DCTSIZE
*7];
3853 tmp5
= dataptr
[DCTSIZE
*5] - dataptr
[DCTSIZE
*6];
3855 dataptr
[DCTSIZE
*0] = (DCTELEM
)
3856 DESCALE(MULTIPLY(tmp10
+ tmp11
+ tmp12
, FIX(0.888888889)), /* 8/9 */
3857 CONST_BITS
+PASS1_BITS
);
3858 dataptr
[DCTSIZE
*6] = (DCTELEM
)
3859 DESCALE(MULTIPLY(tmp13
- tmp14
- tmp15
, FIX(0.888888889)), /* 8/9 */
3860 CONST_BITS
+PASS1_BITS
);
3861 dataptr
[DCTSIZE
*4] = (DCTELEM
)
3862 DESCALE(MULTIPLY(tmp10
- tmp12
, FIX(1.088662108)), /* c4 */
3863 CONST_BITS
+PASS1_BITS
);
3864 dataptr
[DCTSIZE
*2] = (DCTELEM
)
3865 DESCALE(MULTIPLY(tmp14
- tmp15
, FIX(0.888888889)) + /* 8/9 */
3866 MULTIPLY(tmp13
+ tmp15
, FIX(1.214244803)), /* c2 */
3867 CONST_BITS
+PASS1_BITS
);
3871 tmp10
= MULTIPLY(tmp1
+ tmp4
, FIX(0.481063200)); /* c9 */
3872 tmp14
= tmp10
+ MULTIPLY(tmp1
, FIX(0.680326102)); /* c3-c9 */
3873 tmp15
= tmp10
- MULTIPLY(tmp4
, FIX(1.642452502)); /* c3+c9 */
3874 tmp12
= MULTIPLY(tmp0
+ tmp2
, FIX(0.997307603)); /* c5 */
3875 tmp13
= MULTIPLY(tmp0
+ tmp3
, FIX(0.765261039)); /* c7 */
3876 tmp10
= tmp12
+ tmp13
+ tmp14
- MULTIPLY(tmp0
, FIX(0.516244403)) /* c5+c7-c1 */
3877 + MULTIPLY(tmp5
, FIX(0.164081699)); /* c11 */
3878 tmp11
= MULTIPLY(tmp2
+ tmp3
, - FIX(0.164081699)); /* -c11 */
3879 tmp12
+= tmp11
- tmp15
- MULTIPLY(tmp2
, FIX(2.079550144)) /* c1+c5-c11 */
3880 + MULTIPLY(tmp5
, FIX(0.765261039)); /* c7 */
3881 tmp13
+= tmp11
- tmp14
+ MULTIPLY(tmp3
, FIX(0.645144899)) /* c1+c11-c7 */
3882 - MULTIPLY(tmp5
, FIX(0.997307603)); /* c5 */
3883 tmp11
= tmp15
+ MULTIPLY(tmp0
- tmp3
, FIX(1.161389302)) /* c3 */
3884 - MULTIPLY(tmp2
+ tmp5
, FIX(0.481063200)); /* c9 */
3886 dataptr
[DCTSIZE
*1] = (DCTELEM
) DESCALE(tmp10
, CONST_BITS
+PASS1_BITS
);
3887 dataptr
[DCTSIZE
*3] = (DCTELEM
) DESCALE(tmp11
, CONST_BITS
+PASS1_BITS
);
3888 dataptr
[DCTSIZE
*5] = (DCTELEM
) DESCALE(tmp12
, CONST_BITS
+PASS1_BITS
);
3889 dataptr
[DCTSIZE
*7] = (DCTELEM
) DESCALE(tmp13
, CONST_BITS
+PASS1_BITS
);
3891 dataptr
++; /* advance pointer to next column */
3892 wsptr
++; /* advance pointer to next column */
3898 * Perform the forward DCT on a 5x10 sample block.
3900 * 5-point FDCT in pass 1 (rows), 10-point in pass 2 (columns).
3904 jpeg_fdct_5x10 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
3906 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
;
3907 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
;
3908 DCTELEM workspace
[8*2];
3915 /* Pre-zero output coefficient block. */
3916 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
3918 /* Pass 1: process rows.
3919 * Note results are scaled up by sqrt(8) compared to a true DCT;
3920 * furthermore, we scale the results by 2**PASS1_BITS.
3921 * 5-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/10).
3927 elemptr
= sample_data
[ctr
] + start_col
;
3931 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[4]);
3932 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[3]);
3933 tmp2
= GETJSAMPLE(elemptr
[2]);
3935 tmp10
= tmp0
+ tmp1
;
3936 tmp11
= tmp0
- tmp1
;
3938 tmp0
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[4]);
3939 tmp1
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[3]);
3941 /* Apply unsigned->signed conversion */
3942 dataptr
[0] = (DCTELEM
)
3943 ((tmp10
+ tmp2
- 5 * CENTERJSAMPLE
) << PASS1_BITS
);
3944 tmp11
= MULTIPLY(tmp11
, FIX(0.790569415)); /* (c2+c4)/2 */
3946 tmp10
= MULTIPLY(tmp10
, FIX(0.353553391)); /* (c2-c4)/2 */
3947 dataptr
[2] = (DCTELEM
) DESCALE(tmp11
+ tmp10
, CONST_BITS
-PASS1_BITS
);
3948 dataptr
[4] = (DCTELEM
) DESCALE(tmp11
- tmp10
, CONST_BITS
-PASS1_BITS
);
3952 tmp10
= MULTIPLY(tmp0
+ tmp1
, FIX(0.831253876)); /* c3 */
3954 dataptr
[1] = (DCTELEM
)
3955 DESCALE(tmp10
+ MULTIPLY(tmp0
, FIX(0.513743148)), /* c1-c3 */
3956 CONST_BITS
-PASS1_BITS
);
3957 dataptr
[3] = (DCTELEM
)
3958 DESCALE(tmp10
- MULTIPLY(tmp1
, FIX(2.176250899)), /* c1+c3 */
3959 CONST_BITS
-PASS1_BITS
);
3963 if (ctr
!= DCTSIZE
) {
3966 dataptr
+= DCTSIZE
; /* advance pointer to next row */
3968 dataptr
= workspace
; /* switch pointer to extended workspace */
3971 /* Pass 2: process columns.
3972 * We remove the PASS1_BITS scaling, but leave the results scaled up
3973 * by an overall factor of 8.
3974 * We must also scale the output by (8/5)*(8/10) = 32/25, which we
3975 * fold into the constant multipliers:
3976 * 10-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/20) * 32/25.
3981 for (ctr
= 0; ctr
< 5; ctr
++) {
3984 tmp0
= dataptr
[DCTSIZE
*0] + wsptr
[DCTSIZE
*1];
3985 tmp1
= dataptr
[DCTSIZE
*1] + wsptr
[DCTSIZE
*0];
3986 tmp12
= dataptr
[DCTSIZE
*2] + dataptr
[DCTSIZE
*7];
3987 tmp3
= dataptr
[DCTSIZE
*3] + dataptr
[DCTSIZE
*6];
3988 tmp4
= dataptr
[DCTSIZE
*4] + dataptr
[DCTSIZE
*5];
3990 tmp10
= tmp0
+ tmp4
;
3991 tmp13
= tmp0
- tmp4
;
3992 tmp11
= tmp1
+ tmp3
;
3993 tmp14
= tmp1
- tmp3
;
3995 tmp0
= dataptr
[DCTSIZE
*0] - wsptr
[DCTSIZE
*1];
3996 tmp1
= dataptr
[DCTSIZE
*1] - wsptr
[DCTSIZE
*0];
3997 tmp2
= dataptr
[DCTSIZE
*2] - dataptr
[DCTSIZE
*7];
3998 tmp3
= dataptr
[DCTSIZE
*3] - dataptr
[DCTSIZE
*6];
3999 tmp4
= dataptr
[DCTSIZE
*4] - dataptr
[DCTSIZE
*5];
4001 dataptr
[DCTSIZE
*0] = (DCTELEM
)
4002 DESCALE(MULTIPLY(tmp10
+ tmp11
+ tmp12
, FIX(1.28)), /* 32/25 */
4003 CONST_BITS
+PASS1_BITS
);
4005 dataptr
[DCTSIZE
*4] = (DCTELEM
)
4006 DESCALE(MULTIPLY(tmp10
- tmp12
, FIX(1.464477191)) - /* c4 */
4007 MULTIPLY(tmp11
- tmp12
, FIX(0.559380511)), /* c8 */
4008 CONST_BITS
+PASS1_BITS
);
4009 tmp10
= MULTIPLY(tmp13
+ tmp14
, FIX(1.064004961)); /* c6 */
4010 dataptr
[DCTSIZE
*2] = (DCTELEM
)
4011 DESCALE(tmp10
+ MULTIPLY(tmp13
, FIX(0.657591230)), /* c2-c6 */
4012 CONST_BITS
+PASS1_BITS
);
4013 dataptr
[DCTSIZE
*6] = (DCTELEM
)
4014 DESCALE(tmp10
- MULTIPLY(tmp14
, FIX(2.785601151)), /* c2+c6 */
4015 CONST_BITS
+PASS1_BITS
);
4019 tmp10
= tmp0
+ tmp4
;
4020 tmp11
= tmp1
- tmp3
;
4021 dataptr
[DCTSIZE
*5] = (DCTELEM
)
4022 DESCALE(MULTIPLY(tmp10
- tmp11
- tmp2
, FIX(1.28)), /* 32/25 */
4023 CONST_BITS
+PASS1_BITS
);
4024 tmp2
= MULTIPLY(tmp2
, FIX(1.28)); /* 32/25 */
4025 dataptr
[DCTSIZE
*1] = (DCTELEM
)
4026 DESCALE(MULTIPLY(tmp0
, FIX(1.787906876)) + /* c1 */
4027 MULTIPLY(tmp1
, FIX(1.612894094)) + tmp2
+ /* c3 */
4028 MULTIPLY(tmp3
, FIX(0.821810588)) + /* c7 */
4029 MULTIPLY(tmp4
, FIX(0.283176630)), /* c9 */
4030 CONST_BITS
+PASS1_BITS
);
4031 tmp12
= MULTIPLY(tmp0
- tmp4
, FIX(1.217352341)) - /* (c3+c7)/2 */
4032 MULTIPLY(tmp1
+ tmp3
, FIX(0.752365123)); /* (c1-c9)/2 */
4033 tmp13
= MULTIPLY(tmp10
+ tmp11
, FIX(0.395541753)) + /* (c3-c7)/2 */
4034 MULTIPLY(tmp11
, FIX(0.64)) - tmp2
; /* 16/25 */
4035 dataptr
[DCTSIZE
*3] = (DCTELEM
) DESCALE(tmp12
+ tmp13
, CONST_BITS
+PASS1_BITS
);
4036 dataptr
[DCTSIZE
*7] = (DCTELEM
) DESCALE(tmp12
- tmp13
, CONST_BITS
+PASS1_BITS
);
4038 dataptr
++; /* advance pointer to next column */
4039 wsptr
++; /* advance pointer to next column */
4045 * Perform the forward DCT on a 4x8 sample block.
4047 * 4-point FDCT in pass 1 (rows), 8-point in pass 2 (columns).
4051 jpeg_fdct_4x8 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
4053 INT32 tmp0
, tmp1
, tmp2
, tmp3
;
4054 INT32 tmp10
, tmp11
, tmp12
, tmp13
;
4061 /* Pre-zero output coefficient block. */
4062 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
4064 /* Pass 1: process rows.
4065 * Note results are scaled up by sqrt(8) compared to a true DCT;
4066 * furthermore, we scale the results by 2**PASS1_BITS.
4067 * We must also scale the output by 8/4 = 2, which we add here.
4068 * 4-point FDCT kernel,
4069 * cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point FDCT].
4073 for (ctr
= 0; ctr
< DCTSIZE
; ctr
++) {
4074 elemptr
= sample_data
[ctr
] + start_col
;
4078 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[3]);
4079 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[2]);
4081 tmp10
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[3]);
4082 tmp11
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[2]);
4084 /* Apply unsigned->signed conversion */
4085 dataptr
[0] = (DCTELEM
)
4086 ((tmp0
+ tmp1
- 4 * CENTERJSAMPLE
) << (PASS1_BITS
+1));
4087 dataptr
[2] = (DCTELEM
) ((tmp0
- tmp1
) << (PASS1_BITS
+1));
4091 tmp0
= MULTIPLY(tmp10
+ tmp11
, FIX_0_541196100
); /* c6 */
4092 /* Add fudge factor here for final descale. */
4093 tmp0
+= ONE
<< (CONST_BITS
-PASS1_BITS
-2);
4095 dataptr
[1] = (DCTELEM
)
4096 RIGHT_SHIFT(tmp0
+ MULTIPLY(tmp10
, FIX_0_765366865
), /* c2-c6 */
4097 CONST_BITS
-PASS1_BITS
-1);
4098 dataptr
[3] = (DCTELEM
)
4099 RIGHT_SHIFT(tmp0
- MULTIPLY(tmp11
, FIX_1_847759065
), /* c2+c6 */
4100 CONST_BITS
-PASS1_BITS
-1);
4102 dataptr
+= DCTSIZE
; /* advance pointer to next row */
4105 /* Pass 2: process columns.
4106 * We remove the PASS1_BITS scaling, but leave the results scaled up
4107 * by an overall factor of 8.
4108 * 8-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
4112 for (ctr
= 0; ctr
< 4; ctr
++) {
4113 /* Even part per LL&M figure 1 --- note that published figure is faulty;
4114 * rotator "c1" should be "c6".
4117 tmp0
= dataptr
[DCTSIZE
*0] + dataptr
[DCTSIZE
*7];
4118 tmp1
= dataptr
[DCTSIZE
*1] + dataptr
[DCTSIZE
*6];
4119 tmp2
= dataptr
[DCTSIZE
*2] + dataptr
[DCTSIZE
*5];
4120 tmp3
= dataptr
[DCTSIZE
*3] + dataptr
[DCTSIZE
*4];
4122 /* Add fudge factor here for final descale. */
4123 tmp10
= tmp0
+ tmp3
+ (ONE
<< (PASS1_BITS
-1));
4124 tmp12
= tmp0
- tmp3
;
4125 tmp11
= tmp1
+ tmp2
;
4126 tmp13
= tmp1
- tmp2
;
4128 tmp0
= dataptr
[DCTSIZE
*0] - dataptr
[DCTSIZE
*7];
4129 tmp1
= dataptr
[DCTSIZE
*1] - dataptr
[DCTSIZE
*6];
4130 tmp2
= dataptr
[DCTSIZE
*2] - dataptr
[DCTSIZE
*5];
4131 tmp3
= dataptr
[DCTSIZE
*3] - dataptr
[DCTSIZE
*4];
4133 dataptr
[DCTSIZE
*0] = (DCTELEM
) RIGHT_SHIFT(tmp10
+ tmp11
, PASS1_BITS
);
4134 dataptr
[DCTSIZE
*4] = (DCTELEM
) RIGHT_SHIFT(tmp10
- tmp11
, PASS1_BITS
);
4136 z1
= MULTIPLY(tmp12
+ tmp13
, FIX_0_541196100
); /* c6 */
4137 /* Add fudge factor here for final descale. */
4138 z1
+= ONE
<< (CONST_BITS
+PASS1_BITS
-1);
4140 dataptr
[DCTSIZE
*2] = (DCTELEM
)
4141 RIGHT_SHIFT(z1
+ MULTIPLY(tmp12
, FIX_0_765366865
), /* c2-c6 */
4142 CONST_BITS
+PASS1_BITS
);
4143 dataptr
[DCTSIZE
*6] = (DCTELEM
)
4144 RIGHT_SHIFT(z1
- MULTIPLY(tmp13
, FIX_1_847759065
), /* c2+c6 */
4145 CONST_BITS
+PASS1_BITS
);
4147 /* Odd part per figure 8 --- note paper omits factor of sqrt(2).
4148 * i0..i3 in the paper are tmp0..tmp3 here.
4151 tmp12
= tmp0
+ tmp2
;
4152 tmp13
= tmp1
+ tmp3
;
4154 z1
= MULTIPLY(tmp12
+ tmp13
, FIX_1_175875602
); /* c3 */
4155 /* Add fudge factor here for final descale. */
4156 z1
+= ONE
<< (CONST_BITS
+PASS1_BITS
-1);
4158 tmp12
= MULTIPLY(tmp12
, - FIX_0_390180644
); /* -c3+c5 */
4159 tmp13
= MULTIPLY(tmp13
, - FIX_1_961570560
); /* -c3-c5 */
4163 z1
= MULTIPLY(tmp0
+ tmp3
, - FIX_0_899976223
); /* -c3+c7 */
4164 tmp0
= MULTIPLY(tmp0
, FIX_1_501321110
); /* c1+c3-c5-c7 */
4165 tmp3
= MULTIPLY(tmp3
, FIX_0_298631336
); /* -c1+c3+c5-c7 */
4169 z1
= MULTIPLY(tmp1
+ tmp2
, - FIX_2_562915447
); /* -c1-c3 */
4170 tmp1
= MULTIPLY(tmp1
, FIX_3_072711026
); /* c1+c3+c5-c7 */
4171 tmp2
= MULTIPLY(tmp2
, FIX_2_053119869
); /* c1+c3-c5+c7 */
4175 dataptr
[DCTSIZE
*1] = (DCTELEM
) RIGHT_SHIFT(tmp0
, CONST_BITS
+PASS1_BITS
);
4176 dataptr
[DCTSIZE
*3] = (DCTELEM
) RIGHT_SHIFT(tmp1
, CONST_BITS
+PASS1_BITS
);
4177 dataptr
[DCTSIZE
*5] = (DCTELEM
) RIGHT_SHIFT(tmp2
, CONST_BITS
+PASS1_BITS
);
4178 dataptr
[DCTSIZE
*7] = (DCTELEM
) RIGHT_SHIFT(tmp3
, CONST_BITS
+PASS1_BITS
);
4180 dataptr
++; /* advance pointer to next column */
4186 * Perform the forward DCT on a 3x6 sample block.
4188 * 3-point FDCT in pass 1 (rows), 6-point in pass 2 (columns).
4192 jpeg_fdct_3x6 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
4194 INT32 tmp0
, tmp1
, tmp2
;
4195 INT32 tmp10
, tmp11
, tmp12
;
4201 /* Pre-zero output coefficient block. */
4202 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
4204 /* Pass 1: process rows.
4205 * Note results are scaled up by sqrt(8) compared to a true DCT;
4206 * furthermore, we scale the results by 2**PASS1_BITS.
4207 * We scale the results further by 2 as part of output adaption
4208 * scaling for different DCT size.
4209 * 3-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/6).
4213 for (ctr
= 0; ctr
< 6; ctr
++) {
4214 elemptr
= sample_data
[ctr
] + start_col
;
4218 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[2]);
4219 tmp1
= GETJSAMPLE(elemptr
[1]);
4221 tmp2
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[2]);
4223 /* Apply unsigned->signed conversion */
4224 dataptr
[0] = (DCTELEM
)
4225 ((tmp0
+ tmp1
- 3 * CENTERJSAMPLE
) << (PASS1_BITS
+1));
4226 dataptr
[2] = (DCTELEM
)
4227 DESCALE(MULTIPLY(tmp0
- tmp1
- tmp1
, FIX(0.707106781)), /* c2 */
4228 CONST_BITS
-PASS1_BITS
-1);
4232 dataptr
[1] = (DCTELEM
)
4233 DESCALE(MULTIPLY(tmp2
, FIX(1.224744871)), /* c1 */
4234 CONST_BITS
-PASS1_BITS
-1);
4236 dataptr
+= DCTSIZE
; /* advance pointer to next row */
4239 /* Pass 2: process columns.
4240 * We remove the PASS1_BITS scaling, but leave the results scaled up
4241 * by an overall factor of 8.
4242 * We must also scale the output by (8/6)*(8/3) = 32/9, which we partially
4243 * fold into the constant multipliers (other part was done in pass 1):
4244 * 6-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/12) * 16/9.
4248 for (ctr
= 0; ctr
< 3; ctr
++) {
4251 tmp0
= dataptr
[DCTSIZE
*0] + dataptr
[DCTSIZE
*5];
4252 tmp11
= dataptr
[DCTSIZE
*1] + dataptr
[DCTSIZE
*4];
4253 tmp2
= dataptr
[DCTSIZE
*2] + dataptr
[DCTSIZE
*3];
4255 tmp10
= tmp0
+ tmp2
;
4256 tmp12
= tmp0
- tmp2
;
4258 tmp0
= dataptr
[DCTSIZE
*0] - dataptr
[DCTSIZE
*5];
4259 tmp1
= dataptr
[DCTSIZE
*1] - dataptr
[DCTSIZE
*4];
4260 tmp2
= dataptr
[DCTSIZE
*2] - dataptr
[DCTSIZE
*3];
4262 dataptr
[DCTSIZE
*0] = (DCTELEM
)
4263 DESCALE(MULTIPLY(tmp10
+ tmp11
, FIX(1.777777778)), /* 16/9 */
4264 CONST_BITS
+PASS1_BITS
);
4265 dataptr
[DCTSIZE
*2] = (DCTELEM
)
4266 DESCALE(MULTIPLY(tmp12
, FIX(2.177324216)), /* c2 */
4267 CONST_BITS
+PASS1_BITS
);
4268 dataptr
[DCTSIZE
*4] = (DCTELEM
)
4269 DESCALE(MULTIPLY(tmp10
- tmp11
- tmp11
, FIX(1.257078722)), /* c4 */
4270 CONST_BITS
+PASS1_BITS
);
4274 tmp10
= MULTIPLY(tmp0
+ tmp2
, FIX(0.650711829)); /* c5 */
4276 dataptr
[DCTSIZE
*1] = (DCTELEM
)
4277 DESCALE(tmp10
+ MULTIPLY(tmp0
+ tmp1
, FIX(1.777777778)), /* 16/9 */
4278 CONST_BITS
+PASS1_BITS
);
4279 dataptr
[DCTSIZE
*3] = (DCTELEM
)
4280 DESCALE(MULTIPLY(tmp0
- tmp1
- tmp2
, FIX(1.777777778)), /* 16/9 */
4281 CONST_BITS
+PASS1_BITS
);
4282 dataptr
[DCTSIZE
*5] = (DCTELEM
)
4283 DESCALE(tmp10
+ MULTIPLY(tmp2
- tmp1
, FIX(1.777777778)), /* 16/9 */
4284 CONST_BITS
+PASS1_BITS
);
4286 dataptr
++; /* advance pointer to next column */
4292 * Perform the forward DCT on a 2x4 sample block.
4294 * 2-point FDCT in pass 1 (rows), 4-point in pass 2 (columns).
4298 jpeg_fdct_2x4 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
4307 /* Pre-zero output coefficient block. */
4308 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
4310 /* Pass 1: process rows.
4311 * Note results are scaled up by sqrt(8) compared to a true DCT.
4312 * We must also scale the output by (8/2)*(8/4) = 2**3, which we add here.
4316 for (ctr
= 0; ctr
< 4; ctr
++) {
4317 elemptr
= sample_data
[ctr
] + start_col
;
4321 tmp0
= GETJSAMPLE(elemptr
[0]);
4322 tmp1
= GETJSAMPLE(elemptr
[1]);
4324 /* Apply unsigned->signed conversion */
4325 dataptr
[0] = (DCTELEM
) ((tmp0
+ tmp1
- 2 * CENTERJSAMPLE
) << 3);
4329 dataptr
[1] = (DCTELEM
) ((tmp0
- tmp1
) << 3);
4331 dataptr
+= DCTSIZE
; /* advance pointer to next row */
4334 /* Pass 2: process columns.
4335 * We leave the results scaled up by an overall factor of 8.
4336 * 4-point FDCT kernel,
4337 * cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point FDCT].
4341 for (ctr
= 0; ctr
< 2; ctr
++) {
4344 tmp0
= dataptr
[DCTSIZE
*0] + dataptr
[DCTSIZE
*3];
4345 tmp1
= dataptr
[DCTSIZE
*1] + dataptr
[DCTSIZE
*2];
4347 tmp10
= dataptr
[DCTSIZE
*0] - dataptr
[DCTSIZE
*3];
4348 tmp11
= dataptr
[DCTSIZE
*1] - dataptr
[DCTSIZE
*2];
4350 dataptr
[DCTSIZE
*0] = (DCTELEM
) (tmp0
+ tmp1
);
4351 dataptr
[DCTSIZE
*2] = (DCTELEM
) (tmp0
- tmp1
);
4355 tmp0
= MULTIPLY(tmp10
+ tmp11
, FIX_0_541196100
); /* c6 */
4356 /* Add fudge factor here for final descale. */
4357 tmp0
+= ONE
<< (CONST_BITS
-1);
4359 dataptr
[DCTSIZE
*1] = (DCTELEM
)
4360 RIGHT_SHIFT(tmp0
+ MULTIPLY(tmp10
, FIX_0_765366865
), /* c2-c6 */
4362 dataptr
[DCTSIZE
*3] = (DCTELEM
)
4363 RIGHT_SHIFT(tmp0
- MULTIPLY(tmp11
, FIX_1_847759065
), /* c2+c6 */
4366 dataptr
++; /* advance pointer to next column */
4372 * Perform the forward DCT on a 1x2 sample block.
4374 * 1-point FDCT in pass 1 (rows), 2-point in pass 2 (columns).
4378 jpeg_fdct_1x2 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
4382 /* Pre-zero output coefficient block. */
4383 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
4385 /* Pass 1: empty. */
4387 /* Pass 2: process columns.
4388 * We leave the results scaled up by an overall factor of 8.
4389 * We must also scale the output by (8/1)*(8/2) = 2**5.
4394 tmp0
= GETJSAMPLE(sample_data
[0][start_col
]);
4395 tmp1
= GETJSAMPLE(sample_data
[1][start_col
]);
4397 /* Apply unsigned->signed conversion */
4398 data
[DCTSIZE
*0] = (DCTELEM
) ((tmp0
+ tmp1
- 2 * CENTERJSAMPLE
) << 5);
4402 data
[DCTSIZE
*1] = (DCTELEM
) ((tmp0
- tmp1
) << 5);
4405 #endif /* DCT_SCALING_SUPPORTED */
4406 #endif /* DCT_ISLOW_SUPPORTED */