4 * Copyright (C) 1991-1996, Thomas G. Lane.
5 * Modification developed 2003-2009 by Guido Vollbeding.
6 * This file is part of the Independent JPEG Group's software.
7 * For conditions of distribution and use, see the accompanying README file.
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. */
173 for (ctr
= 0; ctr
< DCTSIZE
; ctr
++) {
174 elemptr
= sample_data
[ctr
] + start_col
;
176 /* Even part per LL&M figure 1 --- note that published figure is faulty;
177 * rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
180 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[7]);
181 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[6]);
182 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[5]);
183 tmp3
= GETJSAMPLE(elemptr
[3]) + GETJSAMPLE(elemptr
[4]);
190 tmp0
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[7]);
191 tmp1
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[6]);
192 tmp2
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[5]);
193 tmp3
= GETJSAMPLE(elemptr
[3]) - GETJSAMPLE(elemptr
[4]);
195 /* Apply unsigned->signed conversion */
196 dataptr
[0] = (DCTELEM
) ((tmp10
+ tmp11
- 8 * CENTERJSAMPLE
) << PASS1_BITS
);
197 dataptr
[4] = (DCTELEM
) ((tmp10
- tmp11
) << PASS1_BITS
);
199 z1
= MULTIPLY(tmp12
+ tmp13
, FIX_0_541196100
);
200 /* Add fudge factor here for final descale. */
201 z1
+= ONE
<< (CONST_BITS
-PASS1_BITS
-1);
202 dataptr
[2] = (DCTELEM
) RIGHT_SHIFT(z1
+ MULTIPLY(tmp12
, FIX_0_765366865
),
203 CONST_BITS
-PASS1_BITS
);
204 dataptr
[6] = (DCTELEM
) RIGHT_SHIFT(z1
- MULTIPLY(tmp13
, FIX_1_847759065
),
205 CONST_BITS
-PASS1_BITS
);
207 /* Odd part per figure 8 --- note paper omits factor of sqrt(2).
208 * cK represents sqrt(2) * cos(K*pi/16).
209 * i0..i3 in the paper are tmp0..tmp3 here.
216 z1
= MULTIPLY(tmp12
+ tmp13
, FIX_1_175875602
); /* c3 */
217 /* Add fudge factor here for final descale. */
218 z1
+= ONE
<< (CONST_BITS
-PASS1_BITS
-1);
220 tmp0
= MULTIPLY(tmp0
, FIX_1_501321110
); /* c1+c3-c5-c7 */
221 tmp1
= MULTIPLY(tmp1
, FIX_3_072711026
); /* c1+c3+c5-c7 */
222 tmp2
= MULTIPLY(tmp2
, FIX_2_053119869
); /* c1+c3-c5+c7 */
223 tmp3
= MULTIPLY(tmp3
, FIX_0_298631336
); /* -c1+c3+c5-c7 */
224 tmp10
= MULTIPLY(tmp10
, - FIX_0_899976223
); /* c7-c3 */
225 tmp11
= MULTIPLY(tmp11
, - FIX_2_562915447
); /* -c1-c3 */
226 tmp12
= MULTIPLY(tmp12
, - FIX_0_390180644
); /* c5-c3 */
227 tmp13
= MULTIPLY(tmp13
, - FIX_1_961570560
); /* -c3-c5 */
232 dataptr
[1] = (DCTELEM
)
233 RIGHT_SHIFT(tmp0
+ tmp10
+ tmp12
, CONST_BITS
-PASS1_BITS
);
234 dataptr
[3] = (DCTELEM
)
235 RIGHT_SHIFT(tmp1
+ tmp11
+ tmp13
, CONST_BITS
-PASS1_BITS
);
236 dataptr
[5] = (DCTELEM
)
237 RIGHT_SHIFT(tmp2
+ tmp11
+ tmp12
, CONST_BITS
-PASS1_BITS
);
238 dataptr
[7] = (DCTELEM
)
239 RIGHT_SHIFT(tmp3
+ tmp10
+ tmp13
, CONST_BITS
-PASS1_BITS
);
241 dataptr
+= DCTSIZE
; /* advance pointer to next row */
244 /* Pass 2: process columns.
245 * We remove the PASS1_BITS scaling, but leave the results scaled up
246 * by an overall factor of 8.
250 for (ctr
= DCTSIZE
-1; ctr
>= 0; ctr
--) {
251 /* Even part per LL&M figure 1 --- note that published figure is faulty;
252 * rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
255 tmp0
= dataptr
[DCTSIZE
*0] + dataptr
[DCTSIZE
*7];
256 tmp1
= dataptr
[DCTSIZE
*1] + dataptr
[DCTSIZE
*6];
257 tmp2
= dataptr
[DCTSIZE
*2] + dataptr
[DCTSIZE
*5];
258 tmp3
= dataptr
[DCTSIZE
*3] + dataptr
[DCTSIZE
*4];
260 /* Add fudge factor here for final descale. */
261 tmp10
= tmp0
+ tmp3
+ (ONE
<< (PASS1_BITS
-1));
266 tmp0
= dataptr
[DCTSIZE
*0] - dataptr
[DCTSIZE
*7];
267 tmp1
= dataptr
[DCTSIZE
*1] - dataptr
[DCTSIZE
*6];
268 tmp2
= dataptr
[DCTSIZE
*2] - dataptr
[DCTSIZE
*5];
269 tmp3
= dataptr
[DCTSIZE
*3] - dataptr
[DCTSIZE
*4];
271 dataptr
[DCTSIZE
*0] = (DCTELEM
) RIGHT_SHIFT(tmp10
+ tmp11
, PASS1_BITS
);
272 dataptr
[DCTSIZE
*4] = (DCTELEM
) RIGHT_SHIFT(tmp10
- tmp11
, PASS1_BITS
);
274 z1
= MULTIPLY(tmp12
+ tmp13
, FIX_0_541196100
);
275 /* Add fudge factor here for final descale. */
276 z1
+= ONE
<< (CONST_BITS
+PASS1_BITS
-1);
277 dataptr
[DCTSIZE
*2] = (DCTELEM
)
278 RIGHT_SHIFT(z1
+ MULTIPLY(tmp12
, FIX_0_765366865
), CONST_BITS
+PASS1_BITS
);
279 dataptr
[DCTSIZE
*6] = (DCTELEM
)
280 RIGHT_SHIFT(z1
- MULTIPLY(tmp13
, FIX_1_847759065
), CONST_BITS
+PASS1_BITS
);
282 /* Odd part per figure 8 --- note paper omits factor of sqrt(2).
283 * cK represents sqrt(2) * cos(K*pi/16).
284 * i0..i3 in the paper are tmp0..tmp3 here.
291 z1
= MULTIPLY(tmp12
+ tmp13
, FIX_1_175875602
); /* c3 */
292 /* Add fudge factor here for final descale. */
293 z1
+= ONE
<< (CONST_BITS
+PASS1_BITS
-1);
295 tmp0
= MULTIPLY(tmp0
, FIX_1_501321110
); /* c1+c3-c5-c7 */
296 tmp1
= MULTIPLY(tmp1
, FIX_3_072711026
); /* c1+c3+c5-c7 */
297 tmp2
= MULTIPLY(tmp2
, FIX_2_053119869
); /* c1+c3-c5+c7 */
298 tmp3
= MULTIPLY(tmp3
, FIX_0_298631336
); /* -c1+c3+c5-c7 */
299 tmp10
= MULTIPLY(tmp10
, - FIX_0_899976223
); /* c7-c3 */
300 tmp11
= MULTIPLY(tmp11
, - FIX_2_562915447
); /* -c1-c3 */
301 tmp12
= MULTIPLY(tmp12
, - FIX_0_390180644
); /* c5-c3 */
302 tmp13
= MULTIPLY(tmp13
, - FIX_1_961570560
); /* -c3-c5 */
307 dataptr
[DCTSIZE
*1] = (DCTELEM
)
308 RIGHT_SHIFT(tmp0
+ tmp10
+ tmp12
, CONST_BITS
+PASS1_BITS
);
309 dataptr
[DCTSIZE
*3] = (DCTELEM
)
310 RIGHT_SHIFT(tmp1
+ tmp11
+ tmp13
, CONST_BITS
+PASS1_BITS
);
311 dataptr
[DCTSIZE
*5] = (DCTELEM
)
312 RIGHT_SHIFT(tmp2
+ tmp11
+ tmp12
, CONST_BITS
+PASS1_BITS
);
313 dataptr
[DCTSIZE
*7] = (DCTELEM
)
314 RIGHT_SHIFT(tmp3
+ tmp10
+ tmp13
, CONST_BITS
+PASS1_BITS
);
316 dataptr
++; /* advance pointer to next column */
320 #ifdef DCT_SCALING_SUPPORTED
324 * Perform the forward DCT on a 7x7 sample block.
328 jpeg_fdct_7x7 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
330 INT32 tmp0
, tmp1
, tmp2
, tmp3
;
331 INT32 tmp10
, tmp11
, tmp12
;
338 /* Pre-zero output coefficient block. */
339 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
341 /* Pass 1: process rows. */
342 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
343 /* furthermore, we scale the results by 2**PASS1_BITS. */
344 /* cK represents sqrt(2) * cos(K*pi/14). */
347 for (ctr
= 0; ctr
< 7; ctr
++) {
348 elemptr
= sample_data
[ctr
] + start_col
;
352 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[6]);
353 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[5]);
354 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[4]);
355 tmp3
= GETJSAMPLE(elemptr
[3]);
357 tmp10
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[6]);
358 tmp11
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[5]);
359 tmp12
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[4]);
362 /* Apply unsigned->signed conversion */
363 dataptr
[0] = (DCTELEM
)
364 ((z1
+ tmp1
+ tmp3
- 7 * CENTERJSAMPLE
) << PASS1_BITS
);
368 z1
= MULTIPLY(z1
, FIX(0.353553391)); /* (c2+c6-c4)/2 */
369 z2
= MULTIPLY(tmp0
- tmp2
, FIX(0.920609002)); /* (c2+c4-c6)/2 */
370 z3
= MULTIPLY(tmp1
- tmp2
, FIX(0.314692123)); /* c6 */
371 dataptr
[2] = (DCTELEM
) DESCALE(z1
+ z2
+ z3
, CONST_BITS
-PASS1_BITS
);
373 z2
= MULTIPLY(tmp0
- tmp1
, FIX(0.881747734)); /* c4 */
374 dataptr
[4] = (DCTELEM
)
375 DESCALE(z2
+ z3
- MULTIPLY(tmp1
- tmp3
, FIX(0.707106781)), /* c2+c6-c4 */
376 CONST_BITS
-PASS1_BITS
);
377 dataptr
[6] = (DCTELEM
) DESCALE(z1
+ z2
, CONST_BITS
-PASS1_BITS
);
381 tmp1
= MULTIPLY(tmp10
+ tmp11
, FIX(0.935414347)); /* (c3+c1-c5)/2 */
382 tmp2
= MULTIPLY(tmp10
- tmp11
, FIX(0.170262339)); /* (c3+c5-c1)/2 */
385 tmp2
= MULTIPLY(tmp11
+ tmp12
, - FIX(1.378756276)); /* -c1 */
387 tmp3
= MULTIPLY(tmp10
+ tmp12
, FIX(0.613604268)); /* c5 */
389 tmp2
+= tmp3
+ MULTIPLY(tmp12
, FIX(1.870828693)); /* c3+c1-c5 */
391 dataptr
[1] = (DCTELEM
) DESCALE(tmp0
, CONST_BITS
-PASS1_BITS
);
392 dataptr
[3] = (DCTELEM
) DESCALE(tmp1
, CONST_BITS
-PASS1_BITS
);
393 dataptr
[5] = (DCTELEM
) DESCALE(tmp2
, CONST_BITS
-PASS1_BITS
);
395 dataptr
+= DCTSIZE
; /* advance pointer to next row */
398 /* Pass 2: process columns.
399 * We remove the PASS1_BITS scaling, but leave the results scaled up
400 * by an overall factor of 8.
401 * We must also scale the output by (8/7)**2 = 64/49, which we fold
402 * into the constant multipliers:
403 * cK now represents sqrt(2) * cos(K*pi/14) * 64/49.
407 for (ctr
= 0; ctr
< 7; ctr
++) {
410 tmp0
= dataptr
[DCTSIZE
*0] + dataptr
[DCTSIZE
*6];
411 tmp1
= dataptr
[DCTSIZE
*1] + dataptr
[DCTSIZE
*5];
412 tmp2
= dataptr
[DCTSIZE
*2] + dataptr
[DCTSIZE
*4];
413 tmp3
= dataptr
[DCTSIZE
*3];
415 tmp10
= dataptr
[DCTSIZE
*0] - dataptr
[DCTSIZE
*6];
416 tmp11
= dataptr
[DCTSIZE
*1] - dataptr
[DCTSIZE
*5];
417 tmp12
= dataptr
[DCTSIZE
*2] - dataptr
[DCTSIZE
*4];
420 dataptr
[DCTSIZE
*0] = (DCTELEM
)
421 DESCALE(MULTIPLY(z1
+ tmp1
+ tmp3
, FIX(1.306122449)), /* 64/49 */
422 CONST_BITS
+PASS1_BITS
);
426 z1
= MULTIPLY(z1
, FIX(0.461784020)); /* (c2+c6-c4)/2 */
427 z2
= MULTIPLY(tmp0
- tmp2
, FIX(1.202428084)); /* (c2+c4-c6)/2 */
428 z3
= MULTIPLY(tmp1
- tmp2
, FIX(0.411026446)); /* c6 */
429 dataptr
[DCTSIZE
*2] = (DCTELEM
) DESCALE(z1
+ z2
+ z3
, CONST_BITS
+PASS1_BITS
);
431 z2
= MULTIPLY(tmp0
- tmp1
, FIX(1.151670509)); /* c4 */
432 dataptr
[DCTSIZE
*4] = (DCTELEM
)
433 DESCALE(z2
+ z3
- MULTIPLY(tmp1
- tmp3
, FIX(0.923568041)), /* c2+c6-c4 */
434 CONST_BITS
+PASS1_BITS
);
435 dataptr
[DCTSIZE
*6] = (DCTELEM
) DESCALE(z1
+ z2
, CONST_BITS
+PASS1_BITS
);
439 tmp1
= MULTIPLY(tmp10
+ tmp11
, FIX(1.221765677)); /* (c3+c1-c5)/2 */
440 tmp2
= MULTIPLY(tmp10
- tmp11
, FIX(0.222383464)); /* (c3+c5-c1)/2 */
443 tmp2
= MULTIPLY(tmp11
+ tmp12
, - FIX(1.800824523)); /* -c1 */
445 tmp3
= MULTIPLY(tmp10
+ tmp12
, FIX(0.801442310)); /* c5 */
447 tmp2
+= tmp3
+ MULTIPLY(tmp12
, FIX(2.443531355)); /* c3+c1-c5 */
449 dataptr
[DCTSIZE
*1] = (DCTELEM
) DESCALE(tmp0
, CONST_BITS
+PASS1_BITS
);
450 dataptr
[DCTSIZE
*3] = (DCTELEM
) DESCALE(tmp1
, CONST_BITS
+PASS1_BITS
);
451 dataptr
[DCTSIZE
*5] = (DCTELEM
) DESCALE(tmp2
, CONST_BITS
+PASS1_BITS
);
453 dataptr
++; /* advance pointer to next column */
459 * Perform the forward DCT on a 6x6 sample block.
463 jpeg_fdct_6x6 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
465 INT32 tmp0
, tmp1
, tmp2
;
466 INT32 tmp10
, tmp11
, tmp12
;
472 /* Pre-zero output coefficient block. */
473 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
475 /* Pass 1: process rows. */
476 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
477 /* furthermore, we scale the results by 2**PASS1_BITS. */
478 /* cK represents sqrt(2) * cos(K*pi/12). */
481 for (ctr
= 0; ctr
< 6; ctr
++) {
482 elemptr
= sample_data
[ctr
] + start_col
;
486 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[5]);
487 tmp11
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[4]);
488 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[3]);
493 tmp0
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[5]);
494 tmp1
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[4]);
495 tmp2
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[3]);
497 /* Apply unsigned->signed conversion */
498 dataptr
[0] = (DCTELEM
)
499 ((tmp10
+ tmp11
- 6 * CENTERJSAMPLE
) << PASS1_BITS
);
500 dataptr
[2] = (DCTELEM
)
501 DESCALE(MULTIPLY(tmp12
, FIX(1.224744871)), /* c2 */
502 CONST_BITS
-PASS1_BITS
);
503 dataptr
[4] = (DCTELEM
)
504 DESCALE(MULTIPLY(tmp10
- tmp11
- tmp11
, FIX(0.707106781)), /* c4 */
505 CONST_BITS
-PASS1_BITS
);
509 tmp10
= DESCALE(MULTIPLY(tmp0
+ tmp2
, FIX(0.366025404)), /* c5 */
510 CONST_BITS
-PASS1_BITS
);
512 dataptr
[1] = (DCTELEM
) (tmp10
+ ((tmp0
+ tmp1
) << PASS1_BITS
));
513 dataptr
[3] = (DCTELEM
) ((tmp0
- tmp1
- tmp2
) << PASS1_BITS
);
514 dataptr
[5] = (DCTELEM
) (tmp10
+ ((tmp2
- tmp1
) << PASS1_BITS
));
516 dataptr
+= DCTSIZE
; /* advance pointer to next row */
519 /* Pass 2: process columns.
520 * We remove the PASS1_BITS scaling, but leave the results scaled up
521 * by an overall factor of 8.
522 * We must also scale the output by (8/6)**2 = 16/9, which we fold
523 * into the constant multipliers:
524 * cK now represents sqrt(2) * cos(K*pi/12) * 16/9.
528 for (ctr
= 0; ctr
< 6; ctr
++) {
531 tmp0
= dataptr
[DCTSIZE
*0] + dataptr
[DCTSIZE
*5];
532 tmp11
= dataptr
[DCTSIZE
*1] + dataptr
[DCTSIZE
*4];
533 tmp2
= dataptr
[DCTSIZE
*2] + dataptr
[DCTSIZE
*3];
538 tmp0
= dataptr
[DCTSIZE
*0] - dataptr
[DCTSIZE
*5];
539 tmp1
= dataptr
[DCTSIZE
*1] - dataptr
[DCTSIZE
*4];
540 tmp2
= dataptr
[DCTSIZE
*2] - dataptr
[DCTSIZE
*3];
542 dataptr
[DCTSIZE
*0] = (DCTELEM
)
543 DESCALE(MULTIPLY(tmp10
+ tmp11
, FIX(1.777777778)), /* 16/9 */
544 CONST_BITS
+PASS1_BITS
);
545 dataptr
[DCTSIZE
*2] = (DCTELEM
)
546 DESCALE(MULTIPLY(tmp12
, FIX(2.177324216)), /* c2 */
547 CONST_BITS
+PASS1_BITS
);
548 dataptr
[DCTSIZE
*4] = (DCTELEM
)
549 DESCALE(MULTIPLY(tmp10
- tmp11
- tmp11
, FIX(1.257078722)), /* c4 */
550 CONST_BITS
+PASS1_BITS
);
554 tmp10
= MULTIPLY(tmp0
+ tmp2
, FIX(0.650711829)); /* c5 */
556 dataptr
[DCTSIZE
*1] = (DCTELEM
)
557 DESCALE(tmp10
+ MULTIPLY(tmp0
+ tmp1
, FIX(1.777777778)), /* 16/9 */
558 CONST_BITS
+PASS1_BITS
);
559 dataptr
[DCTSIZE
*3] = (DCTELEM
)
560 DESCALE(MULTIPLY(tmp0
- tmp1
- tmp2
, FIX(1.777777778)), /* 16/9 */
561 CONST_BITS
+PASS1_BITS
);
562 dataptr
[DCTSIZE
*5] = (DCTELEM
)
563 DESCALE(tmp10
+ MULTIPLY(tmp2
- tmp1
, FIX(1.777777778)), /* 16/9 */
564 CONST_BITS
+PASS1_BITS
);
566 dataptr
++; /* advance pointer to next column */
572 * Perform the forward DCT on a 5x5 sample block.
576 jpeg_fdct_5x5 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
578 INT32 tmp0
, tmp1
, tmp2
;
585 /* Pre-zero output coefficient block. */
586 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
588 /* Pass 1: process rows. */
589 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
590 /* furthermore, we scale the results by 2**PASS1_BITS. */
591 /* We scale the results further by 2 as part of output adaption */
592 /* scaling for different DCT size. */
593 /* cK represents sqrt(2) * cos(K*pi/10). */
596 for (ctr
= 0; ctr
< 5; ctr
++) {
597 elemptr
= sample_data
[ctr
] + start_col
;
601 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[4]);
602 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[3]);
603 tmp2
= GETJSAMPLE(elemptr
[2]);
608 tmp0
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[4]);
609 tmp1
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[3]);
611 /* Apply unsigned->signed conversion */
612 dataptr
[0] = (DCTELEM
)
613 ((tmp10
+ tmp2
- 5 * CENTERJSAMPLE
) << (PASS1_BITS
+1));
614 tmp11
= MULTIPLY(tmp11
, FIX(0.790569415)); /* (c2+c4)/2 */
616 tmp10
= MULTIPLY(tmp10
, FIX(0.353553391)); /* (c2-c4)/2 */
617 dataptr
[2] = (DCTELEM
) DESCALE(tmp11
+ tmp10
, CONST_BITS
-PASS1_BITS
-1);
618 dataptr
[4] = (DCTELEM
) DESCALE(tmp11
- tmp10
, CONST_BITS
-PASS1_BITS
-1);
622 tmp10
= MULTIPLY(tmp0
+ tmp1
, FIX(0.831253876)); /* c3 */
624 dataptr
[1] = (DCTELEM
)
625 DESCALE(tmp10
+ MULTIPLY(tmp0
, FIX(0.513743148)), /* c1-c3 */
626 CONST_BITS
-PASS1_BITS
-1);
627 dataptr
[3] = (DCTELEM
)
628 DESCALE(tmp10
- MULTIPLY(tmp1
, FIX(2.176250899)), /* c1+c3 */
629 CONST_BITS
-PASS1_BITS
-1);
631 dataptr
+= DCTSIZE
; /* advance pointer to next row */
634 /* Pass 2: process columns.
635 * We remove the PASS1_BITS scaling, but leave the results scaled up
636 * by an overall factor of 8.
637 * We must also scale the output by (8/5)**2 = 64/25, which we partially
638 * fold into the constant multipliers (other part was done in pass 1):
639 * cK now represents sqrt(2) * cos(K*pi/10) * 32/25.
643 for (ctr
= 0; ctr
< 5; ctr
++) {
646 tmp0
= dataptr
[DCTSIZE
*0] + dataptr
[DCTSIZE
*4];
647 tmp1
= dataptr
[DCTSIZE
*1] + dataptr
[DCTSIZE
*3];
648 tmp2
= dataptr
[DCTSIZE
*2];
653 tmp0
= dataptr
[DCTSIZE
*0] - dataptr
[DCTSIZE
*4];
654 tmp1
= dataptr
[DCTSIZE
*1] - dataptr
[DCTSIZE
*3];
656 dataptr
[DCTSIZE
*0] = (DCTELEM
)
657 DESCALE(MULTIPLY(tmp10
+ tmp2
, FIX(1.28)), /* 32/25 */
658 CONST_BITS
+PASS1_BITS
);
659 tmp11
= MULTIPLY(tmp11
, FIX(1.011928851)); /* (c2+c4)/2 */
661 tmp10
= MULTIPLY(tmp10
, FIX(0.452548340)); /* (c2-c4)/2 */
662 dataptr
[DCTSIZE
*2] = (DCTELEM
) DESCALE(tmp11
+ tmp10
, CONST_BITS
+PASS1_BITS
);
663 dataptr
[DCTSIZE
*4] = (DCTELEM
) DESCALE(tmp11
- tmp10
, CONST_BITS
+PASS1_BITS
);
667 tmp10
= MULTIPLY(tmp0
+ tmp1
, FIX(1.064004961)); /* c3 */
669 dataptr
[DCTSIZE
*1] = (DCTELEM
)
670 DESCALE(tmp10
+ MULTIPLY(tmp0
, FIX(0.657591230)), /* c1-c3 */
671 CONST_BITS
+PASS1_BITS
);
672 dataptr
[DCTSIZE
*3] = (DCTELEM
)
673 DESCALE(tmp10
- MULTIPLY(tmp1
, FIX(2.785601151)), /* c1+c3 */
674 CONST_BITS
+PASS1_BITS
);
676 dataptr
++; /* advance pointer to next column */
682 * Perform the forward DCT on a 4x4 sample block.
686 jpeg_fdct_4x4 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
695 /* Pre-zero output coefficient block. */
696 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
698 /* Pass 1: process rows. */
699 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
700 /* furthermore, we scale the results by 2**PASS1_BITS. */
701 /* We must also scale the output by (8/4)**2 = 2**2, which we add here. */
702 /* cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point FDCT]. */
705 for (ctr
= 0; ctr
< 4; ctr
++) {
706 elemptr
= sample_data
[ctr
] + start_col
;
710 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[3]);
711 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[2]);
713 tmp10
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[3]);
714 tmp11
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[2]);
716 /* Apply unsigned->signed conversion */
717 dataptr
[0] = (DCTELEM
)
718 ((tmp0
+ tmp1
- 4 * CENTERJSAMPLE
) << (PASS1_BITS
+2));
719 dataptr
[2] = (DCTELEM
) ((tmp0
- tmp1
) << (PASS1_BITS
+2));
723 tmp0
= MULTIPLY(tmp10
+ tmp11
, FIX_0_541196100
); /* c6 */
724 /* Add fudge factor here for final descale. */
725 tmp0
+= ONE
<< (CONST_BITS
-PASS1_BITS
-3);
727 dataptr
[1] = (DCTELEM
)
728 RIGHT_SHIFT(tmp0
+ MULTIPLY(tmp10
, FIX_0_765366865
), /* c2-c6 */
729 CONST_BITS
-PASS1_BITS
-2);
730 dataptr
[3] = (DCTELEM
)
731 RIGHT_SHIFT(tmp0
- MULTIPLY(tmp11
, FIX_1_847759065
), /* c2+c6 */
732 CONST_BITS
-PASS1_BITS
-2);
734 dataptr
+= DCTSIZE
; /* advance pointer to next row */
737 /* Pass 2: process columns.
738 * We remove the PASS1_BITS scaling, but leave the results scaled up
739 * by an overall factor of 8.
743 for (ctr
= 0; ctr
< 4; ctr
++) {
746 /* Add fudge factor here for final descale. */
747 tmp0
= dataptr
[DCTSIZE
*0] + dataptr
[DCTSIZE
*3] + (ONE
<< (PASS1_BITS
-1));
748 tmp1
= dataptr
[DCTSIZE
*1] + dataptr
[DCTSIZE
*2];
750 tmp10
= dataptr
[DCTSIZE
*0] - dataptr
[DCTSIZE
*3];
751 tmp11
= dataptr
[DCTSIZE
*1] - dataptr
[DCTSIZE
*2];
753 dataptr
[DCTSIZE
*0] = (DCTELEM
) RIGHT_SHIFT(tmp0
+ tmp1
, PASS1_BITS
);
754 dataptr
[DCTSIZE
*2] = (DCTELEM
) RIGHT_SHIFT(tmp0
- tmp1
, PASS1_BITS
);
758 tmp0
= MULTIPLY(tmp10
+ tmp11
, FIX_0_541196100
); /* c6 */
759 /* Add fudge factor here for final descale. */
760 tmp0
+= ONE
<< (CONST_BITS
+PASS1_BITS
-1);
762 dataptr
[DCTSIZE
*1] = (DCTELEM
)
763 RIGHT_SHIFT(tmp0
+ MULTIPLY(tmp10
, FIX_0_765366865
), /* c2-c6 */
764 CONST_BITS
+PASS1_BITS
);
765 dataptr
[DCTSIZE
*3] = (DCTELEM
)
766 RIGHT_SHIFT(tmp0
- MULTIPLY(tmp11
, FIX_1_847759065
), /* c2+c6 */
767 CONST_BITS
+PASS1_BITS
);
769 dataptr
++; /* advance pointer to next column */
775 * Perform the forward DCT on a 3x3 sample block.
779 jpeg_fdct_3x3 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
781 INT32 tmp0
, tmp1
, tmp2
;
787 /* Pre-zero output coefficient block. */
788 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
790 /* Pass 1: process rows. */
791 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
792 /* furthermore, we scale the results by 2**PASS1_BITS. */
793 /* We scale the results further by 2**2 as part of output adaption */
794 /* scaling for different DCT size. */
795 /* cK represents sqrt(2) * cos(K*pi/6). */
798 for (ctr
= 0; ctr
< 3; ctr
++) {
799 elemptr
= sample_data
[ctr
] + start_col
;
803 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[2]);
804 tmp1
= GETJSAMPLE(elemptr
[1]);
806 tmp2
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[2]);
808 /* Apply unsigned->signed conversion */
809 dataptr
[0] = (DCTELEM
)
810 ((tmp0
+ tmp1
- 3 * CENTERJSAMPLE
) << (PASS1_BITS
+2));
811 dataptr
[2] = (DCTELEM
)
812 DESCALE(MULTIPLY(tmp0
- tmp1
- tmp1
, FIX(0.707106781)), /* c2 */
813 CONST_BITS
-PASS1_BITS
-2);
817 dataptr
[1] = (DCTELEM
)
818 DESCALE(MULTIPLY(tmp2
, FIX(1.224744871)), /* c1 */
819 CONST_BITS
-PASS1_BITS
-2);
821 dataptr
+= DCTSIZE
; /* advance pointer to next row */
824 /* Pass 2: process columns.
825 * We remove the PASS1_BITS scaling, but leave the results scaled up
826 * by an overall factor of 8.
827 * We must also scale the output by (8/3)**2 = 64/9, which we partially
828 * fold into the constant multipliers (other part was done in pass 1):
829 * cK now represents sqrt(2) * cos(K*pi/6) * 16/9.
833 for (ctr
= 0; ctr
< 3; ctr
++) {
836 tmp0
= dataptr
[DCTSIZE
*0] + dataptr
[DCTSIZE
*2];
837 tmp1
= dataptr
[DCTSIZE
*1];
839 tmp2
= dataptr
[DCTSIZE
*0] - dataptr
[DCTSIZE
*2];
841 dataptr
[DCTSIZE
*0] = (DCTELEM
)
842 DESCALE(MULTIPLY(tmp0
+ tmp1
, FIX(1.777777778)), /* 16/9 */
843 CONST_BITS
+PASS1_BITS
);
844 dataptr
[DCTSIZE
*2] = (DCTELEM
)
845 DESCALE(MULTIPLY(tmp0
- tmp1
- tmp1
, FIX(1.257078722)), /* c2 */
846 CONST_BITS
+PASS1_BITS
);
850 dataptr
[DCTSIZE
*1] = (DCTELEM
)
851 DESCALE(MULTIPLY(tmp2
, FIX(2.177324216)), /* c1 */
852 CONST_BITS
+PASS1_BITS
);
854 dataptr
++; /* advance pointer to next column */
860 * Perform the forward DCT on a 2x2 sample block.
864 jpeg_fdct_2x2 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
866 INT32 tmp0
, tmp1
, tmp2
, tmp3
;
869 /* Pre-zero output coefficient block. */
870 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
872 /* Pass 1: process rows. */
873 /* Note results are scaled up by sqrt(8) compared to a true DCT. */
876 elemptr
= sample_data
[0] + start_col
;
878 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[1]);
879 tmp1
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[1]);
882 elemptr
= sample_data
[1] + start_col
;
884 tmp2
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[1]);
885 tmp3
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[1]);
887 /* Pass 2: process columns.
888 * We leave the results scaled up by an overall factor of 8.
889 * We must also scale the output by (8/2)**2 = 2**4.
893 /* Apply unsigned->signed conversion */
894 data
[DCTSIZE
*0] = (DCTELEM
) ((tmp0
+ tmp2
- 4 * CENTERJSAMPLE
) << 4);
895 data
[DCTSIZE
*1] = (DCTELEM
) ((tmp0
- tmp2
) << 4);
898 data
[DCTSIZE
*0+1] = (DCTELEM
) ((tmp1
+ tmp3
) << 4);
899 data
[DCTSIZE
*1+1] = (DCTELEM
) ((tmp1
- tmp3
) << 4);
904 * Perform the forward DCT on a 1x1 sample block.
908 jpeg_fdct_1x1 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
910 /* Pre-zero output coefficient block. */
911 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
913 /* We leave the result scaled up by an overall factor of 8. */
914 /* We must also scale the output by (8/1)**2 = 2**6. */
915 /* Apply unsigned->signed conversion */
917 ((GETJSAMPLE(sample_data
[0][start_col
]) - CENTERJSAMPLE
) << 6);
922 * Perform the forward DCT on a 9x9 sample block.
926 jpeg_fdct_9x9 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
928 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
;
929 INT32 tmp10
, tmp11
, tmp12
, tmp13
;
931 DCTELEM workspace
[8];
938 /* Pass 1: process rows. */
939 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
940 /* we scale the results further by 2 as part of output adaption */
941 /* scaling for different DCT size. */
942 /* cK represents sqrt(2) * cos(K*pi/18). */
947 elemptr
= sample_data
[ctr
] + start_col
;
951 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[8]);
952 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[7]);
953 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[6]);
954 tmp3
= GETJSAMPLE(elemptr
[3]) + GETJSAMPLE(elemptr
[5]);
955 tmp4
= GETJSAMPLE(elemptr
[4]);
957 tmp10
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[8]);
958 tmp11
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[7]);
959 tmp12
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[6]);
960 tmp13
= GETJSAMPLE(elemptr
[3]) - GETJSAMPLE(elemptr
[5]);
962 z1
= tmp0
+ tmp2
+ tmp3
;
964 /* Apply unsigned->signed conversion */
965 dataptr
[0] = (DCTELEM
) ((z1
+ z2
- 9 * CENTERJSAMPLE
) << 1);
966 dataptr
[6] = (DCTELEM
)
967 DESCALE(MULTIPLY(z1
- z2
- z2
, FIX(0.707106781)), /* c6 */
969 z1
= MULTIPLY(tmp0
- tmp2
, FIX(1.328926049)); /* c2 */
970 z2
= MULTIPLY(tmp1
- tmp4
- tmp4
, FIX(0.707106781)); /* c6 */
971 dataptr
[2] = (DCTELEM
)
972 DESCALE(MULTIPLY(tmp2
- tmp3
, FIX(1.083350441)) /* c4 */
973 + z1
+ z2
, CONST_BITS
-1);
974 dataptr
[4] = (DCTELEM
)
975 DESCALE(MULTIPLY(tmp3
- tmp0
, FIX(0.245575608)) /* c8 */
976 + z1
- z2
, CONST_BITS
-1);
980 dataptr
[3] = (DCTELEM
)
981 DESCALE(MULTIPLY(tmp10
- tmp12
- tmp13
, FIX(1.224744871)), /* c3 */
984 tmp11
= MULTIPLY(tmp11
, FIX(1.224744871)); /* c3 */
985 tmp0
= MULTIPLY(tmp10
+ tmp12
, FIX(0.909038955)); /* c5 */
986 tmp1
= MULTIPLY(tmp10
+ tmp13
, FIX(0.483689525)); /* c7 */
988 dataptr
[1] = (DCTELEM
) DESCALE(tmp11
+ tmp0
+ tmp1
, CONST_BITS
-1);
990 tmp2
= MULTIPLY(tmp12
- tmp13
, FIX(1.392728481)); /* c1 */
992 dataptr
[5] = (DCTELEM
) DESCALE(tmp0
- tmp11
- tmp2
, CONST_BITS
-1);
993 dataptr
[7] = (DCTELEM
) DESCALE(tmp1
- tmp11
+ tmp2
, CONST_BITS
-1);
997 if (ctr
!= DCTSIZE
) {
1000 dataptr
+= DCTSIZE
; /* advance pointer to next row */
1002 dataptr
= workspace
; /* switch pointer to extended workspace */
1005 /* Pass 2: process columns.
1006 * We leave the results scaled up by an overall factor of 8.
1007 * We must also scale the output by (8/9)**2 = 64/81, which we partially
1008 * fold into the constant multipliers and final/initial shifting:
1009 * cK now represents sqrt(2) * cos(K*pi/18) * 128/81.
1014 for (ctr
= DCTSIZE
-1; ctr
>= 0; ctr
--) {
1017 tmp0
= dataptr
[DCTSIZE
*0] + wsptr
[DCTSIZE
*0];
1018 tmp1
= dataptr
[DCTSIZE
*1] + dataptr
[DCTSIZE
*7];
1019 tmp2
= dataptr
[DCTSIZE
*2] + dataptr
[DCTSIZE
*6];
1020 tmp3
= dataptr
[DCTSIZE
*3] + dataptr
[DCTSIZE
*5];
1021 tmp4
= dataptr
[DCTSIZE
*4];
1023 tmp10
= dataptr
[DCTSIZE
*0] - wsptr
[DCTSIZE
*0];
1024 tmp11
= dataptr
[DCTSIZE
*1] - dataptr
[DCTSIZE
*7];
1025 tmp12
= dataptr
[DCTSIZE
*2] - dataptr
[DCTSIZE
*6];
1026 tmp13
= dataptr
[DCTSIZE
*3] - dataptr
[DCTSIZE
*5];
1028 z1
= tmp0
+ tmp2
+ tmp3
;
1030 dataptr
[DCTSIZE
*0] = (DCTELEM
)
1031 DESCALE(MULTIPLY(z1
+ z2
, FIX(1.580246914)), /* 128/81 */
1033 dataptr
[DCTSIZE
*6] = (DCTELEM
)
1034 DESCALE(MULTIPLY(z1
- z2
- z2
, FIX(1.117403309)), /* c6 */
1036 z1
= MULTIPLY(tmp0
- tmp2
, FIX(2.100031287)); /* c2 */
1037 z2
= MULTIPLY(tmp1
- tmp4
- tmp4
, FIX(1.117403309)); /* c6 */
1038 dataptr
[DCTSIZE
*2] = (DCTELEM
)
1039 DESCALE(MULTIPLY(tmp2
- tmp3
, FIX(1.711961190)) /* c4 */
1040 + z1
+ z2
, CONST_BITS
+2);
1041 dataptr
[DCTSIZE
*4] = (DCTELEM
)
1042 DESCALE(MULTIPLY(tmp3
- tmp0
, FIX(0.388070096)) /* c8 */
1043 + z1
- z2
, CONST_BITS
+2);
1047 dataptr
[DCTSIZE
*3] = (DCTELEM
)
1048 DESCALE(MULTIPLY(tmp10
- tmp12
- tmp13
, FIX(1.935399303)), /* c3 */
1051 tmp11
= MULTIPLY(tmp11
, FIX(1.935399303)); /* c3 */
1052 tmp0
= MULTIPLY(tmp10
+ tmp12
, FIX(1.436506004)); /* c5 */
1053 tmp1
= MULTIPLY(tmp10
+ tmp13
, FIX(0.764348879)); /* c7 */
1055 dataptr
[DCTSIZE
*1] = (DCTELEM
)
1056 DESCALE(tmp11
+ tmp0
+ tmp1
, CONST_BITS
+2);
1058 tmp2
= MULTIPLY(tmp12
- tmp13
, FIX(2.200854883)); /* c1 */
1060 dataptr
[DCTSIZE
*5] = (DCTELEM
)
1061 DESCALE(tmp0
- tmp11
- tmp2
, CONST_BITS
+2);
1062 dataptr
[DCTSIZE
*7] = (DCTELEM
)
1063 DESCALE(tmp1
- tmp11
+ tmp2
, CONST_BITS
+2);
1065 dataptr
++; /* advance pointer to next column */
1066 wsptr
++; /* advance pointer to next column */
1072 * Perform the forward DCT on a 10x10 sample block.
1076 jpeg_fdct_10x10 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
1078 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
;
1079 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
;
1080 DCTELEM workspace
[8*2];
1087 /* Pass 1: process rows. */
1088 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
1089 /* we scale the results further by 2 as part of output adaption */
1090 /* scaling for different DCT size. */
1091 /* cK represents sqrt(2) * cos(K*pi/20). */
1096 elemptr
= sample_data
[ctr
] + start_col
;
1100 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[9]);
1101 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[8]);
1102 tmp12
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[7]);
1103 tmp3
= GETJSAMPLE(elemptr
[3]) + GETJSAMPLE(elemptr
[6]);
1104 tmp4
= GETJSAMPLE(elemptr
[4]) + GETJSAMPLE(elemptr
[5]);
1106 tmp10
= tmp0
+ tmp4
;
1107 tmp13
= tmp0
- tmp4
;
1108 tmp11
= tmp1
+ tmp3
;
1109 tmp14
= tmp1
- tmp3
;
1111 tmp0
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[9]);
1112 tmp1
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[8]);
1113 tmp2
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[7]);
1114 tmp3
= GETJSAMPLE(elemptr
[3]) - GETJSAMPLE(elemptr
[6]);
1115 tmp4
= GETJSAMPLE(elemptr
[4]) - GETJSAMPLE(elemptr
[5]);
1117 /* Apply unsigned->signed conversion */
1118 dataptr
[0] = (DCTELEM
)
1119 ((tmp10
+ tmp11
+ tmp12
- 10 * CENTERJSAMPLE
) << 1);
1121 dataptr
[4] = (DCTELEM
)
1122 DESCALE(MULTIPLY(tmp10
- tmp12
, FIX(1.144122806)) - /* c4 */
1123 MULTIPLY(tmp11
- tmp12
, FIX(0.437016024)), /* c8 */
1125 tmp10
= MULTIPLY(tmp13
+ tmp14
, FIX(0.831253876)); /* c6 */
1126 dataptr
[2] = (DCTELEM
)
1127 DESCALE(tmp10
+ MULTIPLY(tmp13
, FIX(0.513743148)), /* c2-c6 */
1129 dataptr
[6] = (DCTELEM
)
1130 DESCALE(tmp10
- MULTIPLY(tmp14
, FIX(2.176250899)), /* c2+c6 */
1135 tmp10
= tmp0
+ tmp4
;
1136 tmp11
= tmp1
- tmp3
;
1137 dataptr
[5] = (DCTELEM
) ((tmp10
- tmp11
- tmp2
) << 1);
1138 tmp2
<<= CONST_BITS
;
1139 dataptr
[1] = (DCTELEM
)
1140 DESCALE(MULTIPLY(tmp0
, FIX(1.396802247)) + /* c1 */
1141 MULTIPLY(tmp1
, FIX(1.260073511)) + tmp2
+ /* c3 */
1142 MULTIPLY(tmp3
, FIX(0.642039522)) + /* c7 */
1143 MULTIPLY(tmp4
, FIX(0.221231742)), /* c9 */
1145 tmp12
= MULTIPLY(tmp0
- tmp4
, FIX(0.951056516)) - /* (c3+c7)/2 */
1146 MULTIPLY(tmp1
+ tmp3
, FIX(0.587785252)); /* (c1-c9)/2 */
1147 tmp13
= MULTIPLY(tmp10
+ tmp11
, FIX(0.309016994)) + /* (c3-c7)/2 */
1148 (tmp11
<< (CONST_BITS
- 1)) - tmp2
;
1149 dataptr
[3] = (DCTELEM
) DESCALE(tmp12
+ tmp13
, CONST_BITS
-1);
1150 dataptr
[7] = (DCTELEM
) DESCALE(tmp12
- tmp13
, CONST_BITS
-1);
1154 if (ctr
!= DCTSIZE
) {
1157 dataptr
+= DCTSIZE
; /* advance pointer to next row */
1159 dataptr
= workspace
; /* switch pointer to extended workspace */
1162 /* Pass 2: process columns.
1163 * We leave the results scaled up by an overall factor of 8.
1164 * We must also scale the output by (8/10)**2 = 16/25, which we partially
1165 * fold into the constant multipliers and final/initial shifting:
1166 * cK now represents sqrt(2) * cos(K*pi/20) * 32/25.
1171 for (ctr
= DCTSIZE
-1; ctr
>= 0; ctr
--) {
1174 tmp0
= dataptr
[DCTSIZE
*0] + wsptr
[DCTSIZE
*1];
1175 tmp1
= dataptr
[DCTSIZE
*1] + wsptr
[DCTSIZE
*0];
1176 tmp12
= dataptr
[DCTSIZE
*2] + dataptr
[DCTSIZE
*7];
1177 tmp3
= dataptr
[DCTSIZE
*3] + dataptr
[DCTSIZE
*6];
1178 tmp4
= dataptr
[DCTSIZE
*4] + dataptr
[DCTSIZE
*5];
1180 tmp10
= tmp0
+ tmp4
;
1181 tmp13
= tmp0
- tmp4
;
1182 tmp11
= tmp1
+ tmp3
;
1183 tmp14
= tmp1
- tmp3
;
1185 tmp0
= dataptr
[DCTSIZE
*0] - wsptr
[DCTSIZE
*1];
1186 tmp1
= dataptr
[DCTSIZE
*1] - wsptr
[DCTSIZE
*0];
1187 tmp2
= dataptr
[DCTSIZE
*2] - dataptr
[DCTSIZE
*7];
1188 tmp3
= dataptr
[DCTSIZE
*3] - dataptr
[DCTSIZE
*6];
1189 tmp4
= dataptr
[DCTSIZE
*4] - dataptr
[DCTSIZE
*5];
1191 dataptr
[DCTSIZE
*0] = (DCTELEM
)
1192 DESCALE(MULTIPLY(tmp10
+ tmp11
+ tmp12
, FIX(1.28)), /* 32/25 */
1195 dataptr
[DCTSIZE
*4] = (DCTELEM
)
1196 DESCALE(MULTIPLY(tmp10
- tmp12
, FIX(1.464477191)) - /* c4 */
1197 MULTIPLY(tmp11
- tmp12
, FIX(0.559380511)), /* c8 */
1199 tmp10
= MULTIPLY(tmp13
+ tmp14
, FIX(1.064004961)); /* c6 */
1200 dataptr
[DCTSIZE
*2] = (DCTELEM
)
1201 DESCALE(tmp10
+ MULTIPLY(tmp13
, FIX(0.657591230)), /* c2-c6 */
1203 dataptr
[DCTSIZE
*6] = (DCTELEM
)
1204 DESCALE(tmp10
- MULTIPLY(tmp14
, FIX(2.785601151)), /* c2+c6 */
1209 tmp10
= tmp0
+ tmp4
;
1210 tmp11
= tmp1
- tmp3
;
1211 dataptr
[DCTSIZE
*5] = (DCTELEM
)
1212 DESCALE(MULTIPLY(tmp10
- tmp11
- tmp2
, FIX(1.28)), /* 32/25 */
1214 tmp2
= MULTIPLY(tmp2
, FIX(1.28)); /* 32/25 */
1215 dataptr
[DCTSIZE
*1] = (DCTELEM
)
1216 DESCALE(MULTIPLY(tmp0
, FIX(1.787906876)) + /* c1 */
1217 MULTIPLY(tmp1
, FIX(1.612894094)) + tmp2
+ /* c3 */
1218 MULTIPLY(tmp3
, FIX(0.821810588)) + /* c7 */
1219 MULTIPLY(tmp4
, FIX(0.283176630)), /* c9 */
1221 tmp12
= MULTIPLY(tmp0
- tmp4
, FIX(1.217352341)) - /* (c3+c7)/2 */
1222 MULTIPLY(tmp1
+ tmp3
, FIX(0.752365123)); /* (c1-c9)/2 */
1223 tmp13
= MULTIPLY(tmp10
+ tmp11
, FIX(0.395541753)) + /* (c3-c7)/2 */
1224 MULTIPLY(tmp11
, FIX(0.64)) - tmp2
; /* 16/25 */
1225 dataptr
[DCTSIZE
*3] = (DCTELEM
) DESCALE(tmp12
+ tmp13
, CONST_BITS
+2);
1226 dataptr
[DCTSIZE
*7] = (DCTELEM
) DESCALE(tmp12
- tmp13
, CONST_BITS
+2);
1228 dataptr
++; /* advance pointer to next column */
1229 wsptr
++; /* advance pointer to next column */
1235 * Perform the forward DCT on an 11x11 sample block.
1239 jpeg_fdct_11x11 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
1241 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
, tmp5
;
1242 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
;
1244 DCTELEM workspace
[8*3];
1251 /* Pass 1: process rows. */
1252 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
1253 /* we scale the results further by 2 as part of output adaption */
1254 /* scaling for different DCT size. */
1255 /* cK represents sqrt(2) * cos(K*pi/22). */
1260 elemptr
= sample_data
[ctr
] + start_col
;
1264 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[10]);
1265 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[9]);
1266 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[8]);
1267 tmp3
= GETJSAMPLE(elemptr
[3]) + GETJSAMPLE(elemptr
[7]);
1268 tmp4
= GETJSAMPLE(elemptr
[4]) + GETJSAMPLE(elemptr
[6]);
1269 tmp5
= GETJSAMPLE(elemptr
[5]);
1271 tmp10
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[10]);
1272 tmp11
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[9]);
1273 tmp12
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[8]);
1274 tmp13
= GETJSAMPLE(elemptr
[3]) - GETJSAMPLE(elemptr
[7]);
1275 tmp14
= GETJSAMPLE(elemptr
[4]) - GETJSAMPLE(elemptr
[6]);
1277 /* Apply unsigned->signed conversion */
1278 dataptr
[0] = (DCTELEM
)
1279 ((tmp0
+ tmp1
+ tmp2
+ tmp3
+ tmp4
+ tmp5
- 11 * CENTERJSAMPLE
) << 1);
1286 z1
= MULTIPLY(tmp0
+ tmp3
, FIX(1.356927976)) + /* c2 */
1287 MULTIPLY(tmp2
+ tmp4
, FIX(0.201263574)); /* c10 */
1288 z2
= MULTIPLY(tmp1
- tmp3
, FIX(0.926112931)); /* c6 */
1289 z3
= MULTIPLY(tmp0
- tmp1
, FIX(1.189712156)); /* c4 */
1290 dataptr
[2] = (DCTELEM
)
1291 DESCALE(z1
+ z2
- MULTIPLY(tmp3
, FIX(1.018300590)) /* c2+c8-c6 */
1292 - MULTIPLY(tmp4
, FIX(1.390975730)), /* c4+c10 */
1294 dataptr
[4] = (DCTELEM
)
1295 DESCALE(z2
+ z3
+ MULTIPLY(tmp1
, FIX(0.062335650)) /* c4-c6-c10 */
1296 - MULTIPLY(tmp2
, FIX(1.356927976)) /* c2 */
1297 + MULTIPLY(tmp4
, FIX(0.587485545)), /* c8 */
1299 dataptr
[6] = (DCTELEM
)
1300 DESCALE(z1
+ z3
- MULTIPLY(tmp0
, FIX(1.620527200)) /* c2+c4-c6 */
1301 - MULTIPLY(tmp2
, FIX(0.788749120)), /* c8+c10 */
1306 tmp1
= MULTIPLY(tmp10
+ tmp11
, FIX(1.286413905)); /* c3 */
1307 tmp2
= MULTIPLY(tmp10
+ tmp12
, FIX(1.068791298)); /* c5 */
1308 tmp3
= MULTIPLY(tmp10
+ tmp13
, FIX(0.764581576)); /* c7 */
1309 tmp0
= tmp1
+ tmp2
+ tmp3
- MULTIPLY(tmp10
, FIX(1.719967871)) /* c7+c5+c3-c1 */
1310 + MULTIPLY(tmp14
, FIX(0.398430003)); /* c9 */
1311 tmp4
= MULTIPLY(tmp11
+ tmp12
, - FIX(0.764581576)); /* -c7 */
1312 tmp5
= MULTIPLY(tmp11
+ tmp13
, - FIX(1.399818907)); /* -c1 */
1313 tmp1
+= tmp4
+ tmp5
+ MULTIPLY(tmp11
, FIX(1.276416582)) /* c9+c7+c1-c3 */
1314 - MULTIPLY(tmp14
, FIX(1.068791298)); /* c5 */
1315 tmp10
= MULTIPLY(tmp12
+ tmp13
, FIX(0.398430003)); /* c9 */
1316 tmp2
+= tmp4
+ tmp10
- MULTIPLY(tmp12
, FIX(1.989053629)) /* c9+c5+c3-c7 */
1317 + MULTIPLY(tmp14
, FIX(1.399818907)); /* c1 */
1318 tmp3
+= tmp5
+ tmp10
+ MULTIPLY(tmp13
, FIX(1.305598626)) /* c1+c5-c9-c7 */
1319 - MULTIPLY(tmp14
, FIX(1.286413905)); /* c3 */
1321 dataptr
[1] = (DCTELEM
) DESCALE(tmp0
, CONST_BITS
-1);
1322 dataptr
[3] = (DCTELEM
) DESCALE(tmp1
, CONST_BITS
-1);
1323 dataptr
[5] = (DCTELEM
) DESCALE(tmp2
, CONST_BITS
-1);
1324 dataptr
[7] = (DCTELEM
) DESCALE(tmp3
, CONST_BITS
-1);
1328 if (ctr
!= DCTSIZE
) {
1331 dataptr
+= DCTSIZE
; /* advance pointer to next row */
1333 dataptr
= workspace
; /* switch pointer to extended workspace */
1336 /* Pass 2: process columns.
1337 * We leave the results scaled up by an overall factor of 8.
1338 * We must also scale the output by (8/11)**2 = 64/121, which we partially
1339 * fold into the constant multipliers and final/initial shifting:
1340 * cK now represents sqrt(2) * cos(K*pi/22) * 128/121.
1345 for (ctr
= DCTSIZE
-1; ctr
>= 0; ctr
--) {
1348 tmp0
= dataptr
[DCTSIZE
*0] + wsptr
[DCTSIZE
*2];
1349 tmp1
= dataptr
[DCTSIZE
*1] + wsptr
[DCTSIZE
*1];
1350 tmp2
= dataptr
[DCTSIZE
*2] + wsptr
[DCTSIZE
*0];
1351 tmp3
= dataptr
[DCTSIZE
*3] + dataptr
[DCTSIZE
*7];
1352 tmp4
= dataptr
[DCTSIZE
*4] + dataptr
[DCTSIZE
*6];
1353 tmp5
= dataptr
[DCTSIZE
*5];
1355 tmp10
= dataptr
[DCTSIZE
*0] - wsptr
[DCTSIZE
*2];
1356 tmp11
= dataptr
[DCTSIZE
*1] - wsptr
[DCTSIZE
*1];
1357 tmp12
= dataptr
[DCTSIZE
*2] - wsptr
[DCTSIZE
*0];
1358 tmp13
= dataptr
[DCTSIZE
*3] - dataptr
[DCTSIZE
*7];
1359 tmp14
= dataptr
[DCTSIZE
*4] - dataptr
[DCTSIZE
*6];
1361 dataptr
[DCTSIZE
*0] = (DCTELEM
)
1362 DESCALE(MULTIPLY(tmp0
+ tmp1
+ tmp2
+ tmp3
+ tmp4
+ tmp5
,
1363 FIX(1.057851240)), /* 128/121 */
1371 z1
= MULTIPLY(tmp0
+ tmp3
, FIX(1.435427942)) + /* c2 */
1372 MULTIPLY(tmp2
+ tmp4
, FIX(0.212906922)); /* c10 */
1373 z2
= MULTIPLY(tmp1
- tmp3
, FIX(0.979689713)); /* c6 */
1374 z3
= MULTIPLY(tmp0
- tmp1
, FIX(1.258538479)); /* c4 */
1375 dataptr
[DCTSIZE
*2] = (DCTELEM
)
1376 DESCALE(z1
+ z2
- MULTIPLY(tmp3
, FIX(1.077210542)) /* c2+c8-c6 */
1377 - MULTIPLY(tmp4
, FIX(1.471445400)), /* c4+c10 */
1379 dataptr
[DCTSIZE
*4] = (DCTELEM
)
1380 DESCALE(z2
+ z3
+ MULTIPLY(tmp1
, FIX(0.065941844)) /* c4-c6-c10 */
1381 - MULTIPLY(tmp2
, FIX(1.435427942)) /* c2 */
1382 + MULTIPLY(tmp4
, FIX(0.621472312)), /* c8 */
1384 dataptr
[DCTSIZE
*6] = (DCTELEM
)
1385 DESCALE(z1
+ z3
- MULTIPLY(tmp0
, FIX(1.714276708)) /* c2+c4-c6 */
1386 - MULTIPLY(tmp2
, FIX(0.834379234)), /* c8+c10 */
1391 tmp1
= MULTIPLY(tmp10
+ tmp11
, FIX(1.360834544)); /* c3 */
1392 tmp2
= MULTIPLY(tmp10
+ tmp12
, FIX(1.130622199)); /* c5 */
1393 tmp3
= MULTIPLY(tmp10
+ tmp13
, FIX(0.808813568)); /* c7 */
1394 tmp0
= tmp1
+ tmp2
+ tmp3
- MULTIPLY(tmp10
, FIX(1.819470145)) /* c7+c5+c3-c1 */
1395 + MULTIPLY(tmp14
, FIX(0.421479672)); /* c9 */
1396 tmp4
= MULTIPLY(tmp11
+ tmp12
, - FIX(0.808813568)); /* -c7 */
1397 tmp5
= MULTIPLY(tmp11
+ tmp13
, - FIX(1.480800167)); /* -c1 */
1398 tmp1
+= tmp4
+ tmp5
+ MULTIPLY(tmp11
, FIX(1.350258864)) /* c9+c7+c1-c3 */
1399 - MULTIPLY(tmp14
, FIX(1.130622199)); /* c5 */
1400 tmp10
= MULTIPLY(tmp12
+ tmp13
, FIX(0.421479672)); /* c9 */
1401 tmp2
+= tmp4
+ tmp10
- MULTIPLY(tmp12
, FIX(2.104122847)) /* c9+c5+c3-c7 */
1402 + MULTIPLY(tmp14
, FIX(1.480800167)); /* c1 */
1403 tmp3
+= tmp5
+ tmp10
+ MULTIPLY(tmp13
, FIX(1.381129125)) /* c1+c5-c9-c7 */
1404 - MULTIPLY(tmp14
, FIX(1.360834544)); /* c3 */
1406 dataptr
[DCTSIZE
*1] = (DCTELEM
) DESCALE(tmp0
, CONST_BITS
+2);
1407 dataptr
[DCTSIZE
*3] = (DCTELEM
) DESCALE(tmp1
, CONST_BITS
+2);
1408 dataptr
[DCTSIZE
*5] = (DCTELEM
) DESCALE(tmp2
, CONST_BITS
+2);
1409 dataptr
[DCTSIZE
*7] = (DCTELEM
) DESCALE(tmp3
, CONST_BITS
+2);
1411 dataptr
++; /* advance pointer to next column */
1412 wsptr
++; /* advance pointer to next column */
1418 * Perform the forward DCT on a 12x12 sample block.
1422 jpeg_fdct_12x12 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
1424 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
, tmp5
;
1425 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
, tmp15
;
1426 DCTELEM workspace
[8*4];
1433 /* Pass 1: process rows. */
1434 /* Note results are scaled up by sqrt(8) compared to a true DCT. */
1435 /* cK represents sqrt(2) * cos(K*pi/24). */
1440 elemptr
= sample_data
[ctr
] + start_col
;
1444 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[11]);
1445 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[10]);
1446 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[9]);
1447 tmp3
= GETJSAMPLE(elemptr
[3]) + GETJSAMPLE(elemptr
[8]);
1448 tmp4
= GETJSAMPLE(elemptr
[4]) + GETJSAMPLE(elemptr
[7]);
1449 tmp5
= GETJSAMPLE(elemptr
[5]) + GETJSAMPLE(elemptr
[6]);
1451 tmp10
= tmp0
+ tmp5
;
1452 tmp13
= tmp0
- tmp5
;
1453 tmp11
= tmp1
+ tmp4
;
1454 tmp14
= tmp1
- tmp4
;
1455 tmp12
= tmp2
+ tmp3
;
1456 tmp15
= tmp2
- tmp3
;
1458 tmp0
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[11]);
1459 tmp1
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[10]);
1460 tmp2
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[9]);
1461 tmp3
= GETJSAMPLE(elemptr
[3]) - GETJSAMPLE(elemptr
[8]);
1462 tmp4
= GETJSAMPLE(elemptr
[4]) - GETJSAMPLE(elemptr
[7]);
1463 tmp5
= GETJSAMPLE(elemptr
[5]) - GETJSAMPLE(elemptr
[6]);
1465 /* Apply unsigned->signed conversion */
1466 dataptr
[0] = (DCTELEM
) (tmp10
+ tmp11
+ tmp12
- 12 * CENTERJSAMPLE
);
1467 dataptr
[6] = (DCTELEM
) (tmp13
- tmp14
- tmp15
);
1468 dataptr
[4] = (DCTELEM
)
1469 DESCALE(MULTIPLY(tmp10
- tmp12
, FIX(1.224744871)), /* c4 */
1471 dataptr
[2] = (DCTELEM
)
1472 DESCALE(tmp14
- tmp15
+ MULTIPLY(tmp13
+ tmp15
, FIX(1.366025404)), /* c2 */
1477 tmp10
= MULTIPLY(tmp1
+ tmp4
, FIX_0_541196100
); /* c9 */
1478 tmp14
= tmp10
+ MULTIPLY(tmp1
, FIX_0_765366865
); /* c3-c9 */
1479 tmp15
= tmp10
- MULTIPLY(tmp4
, FIX_1_847759065
); /* c3+c9 */
1480 tmp12
= MULTIPLY(tmp0
+ tmp2
, FIX(1.121971054)); /* c5 */
1481 tmp13
= MULTIPLY(tmp0
+ tmp3
, FIX(0.860918669)); /* c7 */
1482 tmp10
= tmp12
+ tmp13
+ tmp14
- MULTIPLY(tmp0
, FIX(0.580774953)) /* c5+c7-c1 */
1483 + MULTIPLY(tmp5
, FIX(0.184591911)); /* c11 */
1484 tmp11
= MULTIPLY(tmp2
+ tmp3
, - FIX(0.184591911)); /* -c11 */
1485 tmp12
+= tmp11
- tmp15
- MULTIPLY(tmp2
, FIX(2.339493912)) /* c1+c5-c11 */
1486 + MULTIPLY(tmp5
, FIX(0.860918669)); /* c7 */
1487 tmp13
+= tmp11
- tmp14
+ MULTIPLY(tmp3
, FIX(0.725788011)) /* c1+c11-c7 */
1488 - MULTIPLY(tmp5
, FIX(1.121971054)); /* c5 */
1489 tmp11
= tmp15
+ MULTIPLY(tmp0
- tmp3
, FIX(1.306562965)) /* c3 */
1490 - MULTIPLY(tmp2
+ tmp5
, FIX_0_541196100
); /* c9 */
1492 dataptr
[1] = (DCTELEM
) DESCALE(tmp10
, CONST_BITS
);
1493 dataptr
[3] = (DCTELEM
) DESCALE(tmp11
, CONST_BITS
);
1494 dataptr
[5] = (DCTELEM
) DESCALE(tmp12
, CONST_BITS
);
1495 dataptr
[7] = (DCTELEM
) DESCALE(tmp13
, CONST_BITS
);
1499 if (ctr
!= DCTSIZE
) {
1502 dataptr
+= DCTSIZE
; /* advance pointer to next row */
1504 dataptr
= workspace
; /* switch pointer to extended workspace */
1507 /* Pass 2: process columns.
1508 * We leave the results scaled up by an overall factor of 8.
1509 * We must also scale the output by (8/12)**2 = 4/9, which we partially
1510 * fold into the constant multipliers and final shifting:
1511 * cK now represents sqrt(2) * cos(K*pi/24) * 8/9.
1516 for (ctr
= DCTSIZE
-1; ctr
>= 0; ctr
--) {
1519 tmp0
= dataptr
[DCTSIZE
*0] + wsptr
[DCTSIZE
*3];
1520 tmp1
= dataptr
[DCTSIZE
*1] + wsptr
[DCTSIZE
*2];
1521 tmp2
= dataptr
[DCTSIZE
*2] + wsptr
[DCTSIZE
*1];
1522 tmp3
= dataptr
[DCTSIZE
*3] + wsptr
[DCTSIZE
*0];
1523 tmp4
= dataptr
[DCTSIZE
*4] + dataptr
[DCTSIZE
*7];
1524 tmp5
= dataptr
[DCTSIZE
*5] + dataptr
[DCTSIZE
*6];
1526 tmp10
= tmp0
+ tmp5
;
1527 tmp13
= tmp0
- tmp5
;
1528 tmp11
= tmp1
+ tmp4
;
1529 tmp14
= tmp1
- tmp4
;
1530 tmp12
= tmp2
+ tmp3
;
1531 tmp15
= tmp2
- tmp3
;
1533 tmp0
= dataptr
[DCTSIZE
*0] - wsptr
[DCTSIZE
*3];
1534 tmp1
= dataptr
[DCTSIZE
*1] - wsptr
[DCTSIZE
*2];
1535 tmp2
= dataptr
[DCTSIZE
*2] - wsptr
[DCTSIZE
*1];
1536 tmp3
= dataptr
[DCTSIZE
*3] - wsptr
[DCTSIZE
*0];
1537 tmp4
= dataptr
[DCTSIZE
*4] - dataptr
[DCTSIZE
*7];
1538 tmp5
= dataptr
[DCTSIZE
*5] - dataptr
[DCTSIZE
*6];
1540 dataptr
[DCTSIZE
*0] = (DCTELEM
)
1541 DESCALE(MULTIPLY(tmp10
+ tmp11
+ tmp12
, FIX(0.888888889)), /* 8/9 */
1543 dataptr
[DCTSIZE
*6] = (DCTELEM
)
1544 DESCALE(MULTIPLY(tmp13
- tmp14
- tmp15
, FIX(0.888888889)), /* 8/9 */
1546 dataptr
[DCTSIZE
*4] = (DCTELEM
)
1547 DESCALE(MULTIPLY(tmp10
- tmp12
, FIX(1.088662108)), /* c4 */
1549 dataptr
[DCTSIZE
*2] = (DCTELEM
)
1550 DESCALE(MULTIPLY(tmp14
- tmp15
, FIX(0.888888889)) + /* 8/9 */
1551 MULTIPLY(tmp13
+ tmp15
, FIX(1.214244803)), /* c2 */
1556 tmp10
= MULTIPLY(tmp1
+ tmp4
, FIX(0.481063200)); /* c9 */
1557 tmp14
= tmp10
+ MULTIPLY(tmp1
, FIX(0.680326102)); /* c3-c9 */
1558 tmp15
= tmp10
- MULTIPLY(tmp4
, FIX(1.642452502)); /* c3+c9 */
1559 tmp12
= MULTIPLY(tmp0
+ tmp2
, FIX(0.997307603)); /* c5 */
1560 tmp13
= MULTIPLY(tmp0
+ tmp3
, FIX(0.765261039)); /* c7 */
1561 tmp10
= tmp12
+ tmp13
+ tmp14
- MULTIPLY(tmp0
, FIX(0.516244403)) /* c5+c7-c1 */
1562 + MULTIPLY(tmp5
, FIX(0.164081699)); /* c11 */
1563 tmp11
= MULTIPLY(tmp2
+ tmp3
, - FIX(0.164081699)); /* -c11 */
1564 tmp12
+= tmp11
- tmp15
- MULTIPLY(tmp2
, FIX(2.079550144)) /* c1+c5-c11 */
1565 + MULTIPLY(tmp5
, FIX(0.765261039)); /* c7 */
1566 tmp13
+= tmp11
- tmp14
+ MULTIPLY(tmp3
, FIX(0.645144899)) /* c1+c11-c7 */
1567 - MULTIPLY(tmp5
, FIX(0.997307603)); /* c5 */
1568 tmp11
= tmp15
+ MULTIPLY(tmp0
- tmp3
, FIX(1.161389302)) /* c3 */
1569 - MULTIPLY(tmp2
+ tmp5
, FIX(0.481063200)); /* c9 */
1571 dataptr
[DCTSIZE
*1] = (DCTELEM
) DESCALE(tmp10
, CONST_BITS
+1);
1572 dataptr
[DCTSIZE
*3] = (DCTELEM
) DESCALE(tmp11
, CONST_BITS
+1);
1573 dataptr
[DCTSIZE
*5] = (DCTELEM
) DESCALE(tmp12
, CONST_BITS
+1);
1574 dataptr
[DCTSIZE
*7] = (DCTELEM
) DESCALE(tmp13
, CONST_BITS
+1);
1576 dataptr
++; /* advance pointer to next column */
1577 wsptr
++; /* advance pointer to next column */
1583 * Perform the forward DCT on a 13x13 sample block.
1587 jpeg_fdct_13x13 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
1589 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
, tmp5
, tmp6
;
1590 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
, tmp15
;
1592 DCTELEM workspace
[8*5];
1599 /* Pass 1: process rows. */
1600 /* Note results are scaled up by sqrt(8) compared to a true DCT. */
1601 /* cK represents sqrt(2) * cos(K*pi/26). */
1606 elemptr
= sample_data
[ctr
] + start_col
;
1610 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[12]);
1611 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[11]);
1612 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[10]);
1613 tmp3
= GETJSAMPLE(elemptr
[3]) + GETJSAMPLE(elemptr
[9]);
1614 tmp4
= GETJSAMPLE(elemptr
[4]) + GETJSAMPLE(elemptr
[8]);
1615 tmp5
= GETJSAMPLE(elemptr
[5]) + GETJSAMPLE(elemptr
[7]);
1616 tmp6
= GETJSAMPLE(elemptr
[6]);
1618 tmp10
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[12]);
1619 tmp11
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[11]);
1620 tmp12
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[10]);
1621 tmp13
= GETJSAMPLE(elemptr
[3]) - GETJSAMPLE(elemptr
[9]);
1622 tmp14
= GETJSAMPLE(elemptr
[4]) - GETJSAMPLE(elemptr
[8]);
1623 tmp15
= GETJSAMPLE(elemptr
[5]) - GETJSAMPLE(elemptr
[7]);
1625 /* Apply unsigned->signed conversion */
1626 dataptr
[0] = (DCTELEM
)
1627 (tmp0
+ tmp1
+ tmp2
+ tmp3
+ tmp4
+ tmp5
+ tmp6
- 13 * CENTERJSAMPLE
);
1635 dataptr
[2] = (DCTELEM
)
1636 DESCALE(MULTIPLY(tmp0
, FIX(1.373119086)) + /* c2 */
1637 MULTIPLY(tmp1
, FIX(1.058554052)) + /* c6 */
1638 MULTIPLY(tmp2
, FIX(0.501487041)) - /* c10 */
1639 MULTIPLY(tmp3
, FIX(0.170464608)) - /* c12 */
1640 MULTIPLY(tmp4
, FIX(0.803364869)) - /* c8 */
1641 MULTIPLY(tmp5
, FIX(1.252223920)), /* c4 */
1643 z1
= MULTIPLY(tmp0
- tmp2
, FIX(1.155388986)) - /* (c4+c6)/2 */
1644 MULTIPLY(tmp3
- tmp4
, FIX(0.435816023)) - /* (c2-c10)/2 */
1645 MULTIPLY(tmp1
- tmp5
, FIX(0.316450131)); /* (c8-c12)/2 */
1646 z2
= MULTIPLY(tmp0
+ tmp2
, FIX(0.096834934)) - /* (c4-c6)/2 */
1647 MULTIPLY(tmp3
+ tmp4
, FIX(0.937303064)) + /* (c2+c10)/2 */
1648 MULTIPLY(tmp1
+ tmp5
, FIX(0.486914739)); /* (c8+c12)/2 */
1650 dataptr
[4] = (DCTELEM
) DESCALE(z1
+ z2
, CONST_BITS
);
1651 dataptr
[6] = (DCTELEM
) DESCALE(z1
- z2
, CONST_BITS
);
1655 tmp1
= MULTIPLY(tmp10
+ tmp11
, FIX(1.322312651)); /* c3 */
1656 tmp2
= MULTIPLY(tmp10
+ tmp12
, FIX(1.163874945)); /* c5 */
1657 tmp3
= MULTIPLY(tmp10
+ tmp13
, FIX(0.937797057)) + /* c7 */
1658 MULTIPLY(tmp14
+ tmp15
, FIX(0.338443458)); /* c11 */
1659 tmp0
= tmp1
+ tmp2
+ tmp3
-
1660 MULTIPLY(tmp10
, FIX(2.020082300)) + /* c3+c5+c7-c1 */
1661 MULTIPLY(tmp14
, FIX(0.318774355)); /* c9-c11 */
1662 tmp4
= MULTIPLY(tmp14
- tmp15
, FIX(0.937797057)) - /* c7 */
1663 MULTIPLY(tmp11
+ tmp12
, FIX(0.338443458)); /* c11 */
1664 tmp5
= MULTIPLY(tmp11
+ tmp13
, - FIX(1.163874945)); /* -c5 */
1665 tmp1
+= tmp4
+ tmp5
+
1666 MULTIPLY(tmp11
, FIX(0.837223564)) - /* c5+c9+c11-c3 */
1667 MULTIPLY(tmp14
, FIX(2.341699410)); /* c1+c7 */
1668 tmp6
= MULTIPLY(tmp12
+ tmp13
, - FIX(0.657217813)); /* -c9 */
1669 tmp2
+= tmp4
+ tmp6
-
1670 MULTIPLY(tmp12
, FIX(1.572116027)) + /* c1+c5-c9-c11 */
1671 MULTIPLY(tmp15
, FIX(2.260109708)); /* c3+c7 */
1672 tmp3
+= tmp5
+ tmp6
+
1673 MULTIPLY(tmp13
, FIX(2.205608352)) - /* c3+c5+c9-c7 */
1674 MULTIPLY(tmp15
, FIX(1.742345811)); /* c1+c11 */
1676 dataptr
[1] = (DCTELEM
) DESCALE(tmp0
, CONST_BITS
);
1677 dataptr
[3] = (DCTELEM
) DESCALE(tmp1
, CONST_BITS
);
1678 dataptr
[5] = (DCTELEM
) DESCALE(tmp2
, CONST_BITS
);
1679 dataptr
[7] = (DCTELEM
) DESCALE(tmp3
, CONST_BITS
);
1683 if (ctr
!= DCTSIZE
) {
1686 dataptr
+= DCTSIZE
; /* advance pointer to next row */
1688 dataptr
= workspace
; /* switch pointer to extended workspace */
1691 /* Pass 2: process columns.
1692 * We leave the results scaled up by an overall factor of 8.
1693 * We must also scale the output by (8/13)**2 = 64/169, which we partially
1694 * fold into the constant multipliers and final shifting:
1695 * cK now represents sqrt(2) * cos(K*pi/26) * 128/169.
1700 for (ctr
= DCTSIZE
-1; ctr
>= 0; ctr
--) {
1703 tmp0
= dataptr
[DCTSIZE
*0] + wsptr
[DCTSIZE
*4];
1704 tmp1
= dataptr
[DCTSIZE
*1] + wsptr
[DCTSIZE
*3];
1705 tmp2
= dataptr
[DCTSIZE
*2] + wsptr
[DCTSIZE
*2];
1706 tmp3
= dataptr
[DCTSIZE
*3] + wsptr
[DCTSIZE
*1];
1707 tmp4
= dataptr
[DCTSIZE
*4] + wsptr
[DCTSIZE
*0];
1708 tmp5
= dataptr
[DCTSIZE
*5] + dataptr
[DCTSIZE
*7];
1709 tmp6
= dataptr
[DCTSIZE
*6];
1711 tmp10
= dataptr
[DCTSIZE
*0] - wsptr
[DCTSIZE
*4];
1712 tmp11
= dataptr
[DCTSIZE
*1] - wsptr
[DCTSIZE
*3];
1713 tmp12
= dataptr
[DCTSIZE
*2] - wsptr
[DCTSIZE
*2];
1714 tmp13
= dataptr
[DCTSIZE
*3] - wsptr
[DCTSIZE
*1];
1715 tmp14
= dataptr
[DCTSIZE
*4] - wsptr
[DCTSIZE
*0];
1716 tmp15
= dataptr
[DCTSIZE
*5] - dataptr
[DCTSIZE
*7];
1718 dataptr
[DCTSIZE
*0] = (DCTELEM
)
1719 DESCALE(MULTIPLY(tmp0
+ tmp1
+ tmp2
+ tmp3
+ tmp4
+ tmp5
+ tmp6
,
1720 FIX(0.757396450)), /* 128/169 */
1729 dataptr
[DCTSIZE
*2] = (DCTELEM
)
1730 DESCALE(MULTIPLY(tmp0
, FIX(1.039995521)) + /* c2 */
1731 MULTIPLY(tmp1
, FIX(0.801745081)) + /* c6 */
1732 MULTIPLY(tmp2
, FIX(0.379824504)) - /* c10 */
1733 MULTIPLY(tmp3
, FIX(0.129109289)) - /* c12 */
1734 MULTIPLY(tmp4
, FIX(0.608465700)) - /* c8 */
1735 MULTIPLY(tmp5
, FIX(0.948429952)), /* c4 */
1737 z1
= MULTIPLY(tmp0
- tmp2
, FIX(0.875087516)) - /* (c4+c6)/2 */
1738 MULTIPLY(tmp3
- tmp4
, FIX(0.330085509)) - /* (c2-c10)/2 */
1739 MULTIPLY(tmp1
- tmp5
, FIX(0.239678205)); /* (c8-c12)/2 */
1740 z2
= MULTIPLY(tmp0
+ tmp2
, FIX(0.073342435)) - /* (c4-c6)/2 */
1741 MULTIPLY(tmp3
+ tmp4
, FIX(0.709910013)) + /* (c2+c10)/2 */
1742 MULTIPLY(tmp1
+ tmp5
, FIX(0.368787494)); /* (c8+c12)/2 */
1744 dataptr
[DCTSIZE
*4] = (DCTELEM
) DESCALE(z1
+ z2
, CONST_BITS
+1);
1745 dataptr
[DCTSIZE
*6] = (DCTELEM
) DESCALE(z1
- z2
, CONST_BITS
+1);
1749 tmp1
= MULTIPLY(tmp10
+ tmp11
, FIX(1.001514908)); /* c3 */
1750 tmp2
= MULTIPLY(tmp10
+ tmp12
, FIX(0.881514751)); /* c5 */
1751 tmp3
= MULTIPLY(tmp10
+ tmp13
, FIX(0.710284161)) + /* c7 */
1752 MULTIPLY(tmp14
+ tmp15
, FIX(0.256335874)); /* c11 */
1753 tmp0
= tmp1
+ tmp2
+ tmp3
-
1754 MULTIPLY(tmp10
, FIX(1.530003162)) + /* c3+c5+c7-c1 */
1755 MULTIPLY(tmp14
, FIX(0.241438564)); /* c9-c11 */
1756 tmp4
= MULTIPLY(tmp14
- tmp15
, FIX(0.710284161)) - /* c7 */
1757 MULTIPLY(tmp11
+ tmp12
, FIX(0.256335874)); /* c11 */
1758 tmp5
= MULTIPLY(tmp11
+ tmp13
, - FIX(0.881514751)); /* -c5 */
1759 tmp1
+= tmp4
+ tmp5
+
1760 MULTIPLY(tmp11
, FIX(0.634110155)) - /* c5+c9+c11-c3 */
1761 MULTIPLY(tmp14
, FIX(1.773594819)); /* c1+c7 */
1762 tmp6
= MULTIPLY(tmp12
+ tmp13
, - FIX(0.497774438)); /* -c9 */
1763 tmp2
+= tmp4
+ tmp6
-
1764 MULTIPLY(tmp12
, FIX(1.190715098)) + /* c1+c5-c9-c11 */
1765 MULTIPLY(tmp15
, FIX(1.711799069)); /* c3+c7 */
1766 tmp3
+= tmp5
+ tmp6
+
1767 MULTIPLY(tmp13
, FIX(1.670519935)) - /* c3+c5+c9-c7 */
1768 MULTIPLY(tmp15
, FIX(1.319646532)); /* c1+c11 */
1770 dataptr
[DCTSIZE
*1] = (DCTELEM
) DESCALE(tmp0
, CONST_BITS
+1);
1771 dataptr
[DCTSIZE
*3] = (DCTELEM
) DESCALE(tmp1
, CONST_BITS
+1);
1772 dataptr
[DCTSIZE
*5] = (DCTELEM
) DESCALE(tmp2
, CONST_BITS
+1);
1773 dataptr
[DCTSIZE
*7] = (DCTELEM
) DESCALE(tmp3
, CONST_BITS
+1);
1775 dataptr
++; /* advance pointer to next column */
1776 wsptr
++; /* advance pointer to next column */
1782 * Perform the forward DCT on a 14x14 sample block.
1786 jpeg_fdct_14x14 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
1788 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
, tmp5
, tmp6
;
1789 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
, tmp15
, tmp16
;
1790 DCTELEM workspace
[8*6];
1797 /* Pass 1: process rows. */
1798 /* Note results are scaled up by sqrt(8) compared to a true DCT. */
1799 /* cK represents sqrt(2) * cos(K*pi/28). */
1804 elemptr
= sample_data
[ctr
] + start_col
;
1808 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[13]);
1809 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[12]);
1810 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[11]);
1811 tmp13
= GETJSAMPLE(elemptr
[3]) + GETJSAMPLE(elemptr
[10]);
1812 tmp4
= GETJSAMPLE(elemptr
[4]) + GETJSAMPLE(elemptr
[9]);
1813 tmp5
= GETJSAMPLE(elemptr
[5]) + GETJSAMPLE(elemptr
[8]);
1814 tmp6
= GETJSAMPLE(elemptr
[6]) + GETJSAMPLE(elemptr
[7]);
1816 tmp10
= tmp0
+ tmp6
;
1817 tmp14
= tmp0
- tmp6
;
1818 tmp11
= tmp1
+ tmp5
;
1819 tmp15
= tmp1
- tmp5
;
1820 tmp12
= tmp2
+ tmp4
;
1821 tmp16
= tmp2
- tmp4
;
1823 tmp0
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[13]);
1824 tmp1
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[12]);
1825 tmp2
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[11]);
1826 tmp3
= GETJSAMPLE(elemptr
[3]) - GETJSAMPLE(elemptr
[10]);
1827 tmp4
= GETJSAMPLE(elemptr
[4]) - GETJSAMPLE(elemptr
[9]);
1828 tmp5
= GETJSAMPLE(elemptr
[5]) - GETJSAMPLE(elemptr
[8]);
1829 tmp6
= GETJSAMPLE(elemptr
[6]) - GETJSAMPLE(elemptr
[7]);
1831 /* Apply unsigned->signed conversion */
1832 dataptr
[0] = (DCTELEM
)
1833 (tmp10
+ tmp11
+ tmp12
+ tmp13
- 14 * CENTERJSAMPLE
);
1835 dataptr
[4] = (DCTELEM
)
1836 DESCALE(MULTIPLY(tmp10
- tmp13
, FIX(1.274162392)) + /* c4 */
1837 MULTIPLY(tmp11
- tmp13
, FIX(0.314692123)) - /* c12 */
1838 MULTIPLY(tmp12
- tmp13
, FIX(0.881747734)), /* c8 */
1841 tmp10
= MULTIPLY(tmp14
+ tmp15
, FIX(1.105676686)); /* c6 */
1843 dataptr
[2] = (DCTELEM
)
1844 DESCALE(tmp10
+ MULTIPLY(tmp14
, FIX(0.273079590)) /* c2-c6 */
1845 + MULTIPLY(tmp16
, FIX(0.613604268)), /* c10 */
1847 dataptr
[6] = (DCTELEM
)
1848 DESCALE(tmp10
- MULTIPLY(tmp15
, FIX(1.719280954)) /* c6+c10 */
1849 - MULTIPLY(tmp16
, FIX(1.378756276)), /* c2 */
1854 tmp10
= tmp1
+ tmp2
;
1855 tmp11
= tmp5
- tmp4
;
1856 dataptr
[7] = (DCTELEM
) (tmp0
- tmp10
+ tmp3
- tmp11
- tmp6
);
1857 tmp3
<<= CONST_BITS
;
1858 tmp10
= MULTIPLY(tmp10
, - FIX(0.158341681)); /* -c13 */
1859 tmp11
= MULTIPLY(tmp11
, FIX(1.405321284)); /* c1 */
1860 tmp10
+= tmp11
- tmp3
;
1861 tmp11
= MULTIPLY(tmp0
+ tmp2
, FIX(1.197448846)) + /* c5 */
1862 MULTIPLY(tmp4
+ tmp6
, FIX(0.752406978)); /* c9 */
1863 dataptr
[5] = (DCTELEM
)
1864 DESCALE(tmp10
+ tmp11
- MULTIPLY(tmp2
, FIX(2.373959773)) /* c3+c5-c13 */
1865 + MULTIPLY(tmp4
, FIX(1.119999435)), /* c1+c11-c9 */
1867 tmp12
= MULTIPLY(tmp0
+ tmp1
, FIX(1.334852607)) + /* c3 */
1868 MULTIPLY(tmp5
- tmp6
, FIX(0.467085129)); /* c11 */
1869 dataptr
[3] = (DCTELEM
)
1870 DESCALE(tmp10
+ tmp12
- MULTIPLY(tmp1
, FIX(0.424103948)) /* c3-c9-c13 */
1871 - MULTIPLY(tmp5
, FIX(3.069855259)), /* c1+c5+c11 */
1873 dataptr
[1] = (DCTELEM
)
1874 DESCALE(tmp11
+ tmp12
+ tmp3
+ tmp6
-
1875 MULTIPLY(tmp0
+ tmp6
, FIX(1.126980169)), /* c3+c5-c1 */
1880 if (ctr
!= DCTSIZE
) {
1883 dataptr
+= DCTSIZE
; /* advance pointer to next row */
1885 dataptr
= workspace
; /* switch pointer to extended workspace */
1888 /* Pass 2: process columns.
1889 * We leave the results scaled up by an overall factor of 8.
1890 * We must also scale the output by (8/14)**2 = 16/49, which we partially
1891 * fold into the constant multipliers and final shifting:
1892 * cK now represents sqrt(2) * cos(K*pi/28) * 32/49.
1897 for (ctr
= DCTSIZE
-1; ctr
>= 0; ctr
--) {
1900 tmp0
= dataptr
[DCTSIZE
*0] + wsptr
[DCTSIZE
*5];
1901 tmp1
= dataptr
[DCTSIZE
*1] + wsptr
[DCTSIZE
*4];
1902 tmp2
= dataptr
[DCTSIZE
*2] + wsptr
[DCTSIZE
*3];
1903 tmp13
= dataptr
[DCTSIZE
*3] + wsptr
[DCTSIZE
*2];
1904 tmp4
= dataptr
[DCTSIZE
*4] + wsptr
[DCTSIZE
*1];
1905 tmp5
= dataptr
[DCTSIZE
*5] + wsptr
[DCTSIZE
*0];
1906 tmp6
= dataptr
[DCTSIZE
*6] + dataptr
[DCTSIZE
*7];
1908 tmp10
= tmp0
+ tmp6
;
1909 tmp14
= tmp0
- tmp6
;
1910 tmp11
= tmp1
+ tmp5
;
1911 tmp15
= tmp1
- tmp5
;
1912 tmp12
= tmp2
+ tmp4
;
1913 tmp16
= tmp2
- tmp4
;
1915 tmp0
= dataptr
[DCTSIZE
*0] - wsptr
[DCTSIZE
*5];
1916 tmp1
= dataptr
[DCTSIZE
*1] - wsptr
[DCTSIZE
*4];
1917 tmp2
= dataptr
[DCTSIZE
*2] - wsptr
[DCTSIZE
*3];
1918 tmp3
= dataptr
[DCTSIZE
*3] - wsptr
[DCTSIZE
*2];
1919 tmp4
= dataptr
[DCTSIZE
*4] - wsptr
[DCTSIZE
*1];
1920 tmp5
= dataptr
[DCTSIZE
*5] - wsptr
[DCTSIZE
*0];
1921 tmp6
= dataptr
[DCTSIZE
*6] - dataptr
[DCTSIZE
*7];
1923 dataptr
[DCTSIZE
*0] = (DCTELEM
)
1924 DESCALE(MULTIPLY(tmp10
+ tmp11
+ tmp12
+ tmp13
,
1925 FIX(0.653061224)), /* 32/49 */
1928 dataptr
[DCTSIZE
*4] = (DCTELEM
)
1929 DESCALE(MULTIPLY(tmp10
- tmp13
, FIX(0.832106052)) + /* c4 */
1930 MULTIPLY(tmp11
- tmp13
, FIX(0.205513223)) - /* c12 */
1931 MULTIPLY(tmp12
- tmp13
, FIX(0.575835255)), /* c8 */
1934 tmp10
= MULTIPLY(tmp14
+ tmp15
, FIX(0.722074570)); /* c6 */
1936 dataptr
[DCTSIZE
*2] = (DCTELEM
)
1937 DESCALE(tmp10
+ MULTIPLY(tmp14
, FIX(0.178337691)) /* c2-c6 */
1938 + MULTIPLY(tmp16
, FIX(0.400721155)), /* c10 */
1940 dataptr
[DCTSIZE
*6] = (DCTELEM
)
1941 DESCALE(tmp10
- MULTIPLY(tmp15
, FIX(1.122795725)) /* c6+c10 */
1942 - MULTIPLY(tmp16
, FIX(0.900412262)), /* c2 */
1947 tmp10
= tmp1
+ tmp2
;
1948 tmp11
= tmp5
- tmp4
;
1949 dataptr
[DCTSIZE
*7] = (DCTELEM
)
1950 DESCALE(MULTIPLY(tmp0
- tmp10
+ tmp3
- tmp11
- tmp6
,
1951 FIX(0.653061224)), /* 32/49 */
1953 tmp3
= MULTIPLY(tmp3
, FIX(0.653061224)); /* 32/49 */
1954 tmp10
= MULTIPLY(tmp10
, - FIX(0.103406812)); /* -c13 */
1955 tmp11
= MULTIPLY(tmp11
, FIX(0.917760839)); /* c1 */
1956 tmp10
+= tmp11
- tmp3
;
1957 tmp11
= MULTIPLY(tmp0
+ tmp2
, FIX(0.782007410)) + /* c5 */
1958 MULTIPLY(tmp4
+ tmp6
, FIX(0.491367823)); /* c9 */
1959 dataptr
[DCTSIZE
*5] = (DCTELEM
)
1960 DESCALE(tmp10
+ tmp11
- MULTIPLY(tmp2
, FIX(1.550341076)) /* c3+c5-c13 */
1961 + MULTIPLY(tmp4
, FIX(0.731428202)), /* c1+c11-c9 */
1963 tmp12
= MULTIPLY(tmp0
+ tmp1
, FIX(0.871740478)) + /* c3 */
1964 MULTIPLY(tmp5
- tmp6
, FIX(0.305035186)); /* c11 */
1965 dataptr
[DCTSIZE
*3] = (DCTELEM
)
1966 DESCALE(tmp10
+ tmp12
- MULTIPLY(tmp1
, FIX(0.276965844)) /* c3-c9-c13 */
1967 - MULTIPLY(tmp5
, FIX(2.004803435)), /* c1+c5+c11 */
1969 dataptr
[DCTSIZE
*1] = (DCTELEM
)
1970 DESCALE(tmp11
+ tmp12
+ tmp3
1971 - MULTIPLY(tmp0
, FIX(0.735987049)) /* c3+c5-c1 */
1972 - MULTIPLY(tmp6
, FIX(0.082925825)), /* c9-c11-c13 */
1975 dataptr
++; /* advance pointer to next column */
1976 wsptr
++; /* advance pointer to next column */
1982 * Perform the forward DCT on a 15x15 sample block.
1986 jpeg_fdct_15x15 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
1988 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
, tmp5
, tmp6
, tmp7
;
1989 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
, tmp15
, tmp16
;
1991 DCTELEM workspace
[8*7];
1998 /* Pass 1: process rows. */
1999 /* Note results are scaled up by sqrt(8) compared to a true DCT. */
2000 /* cK represents sqrt(2) * cos(K*pi/30). */
2005 elemptr
= sample_data
[ctr
] + start_col
;
2009 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[14]);
2010 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[13]);
2011 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[12]);
2012 tmp3
= GETJSAMPLE(elemptr
[3]) + GETJSAMPLE(elemptr
[11]);
2013 tmp4
= GETJSAMPLE(elemptr
[4]) + GETJSAMPLE(elemptr
[10]);
2014 tmp5
= GETJSAMPLE(elemptr
[5]) + GETJSAMPLE(elemptr
[9]);
2015 tmp6
= GETJSAMPLE(elemptr
[6]) + GETJSAMPLE(elemptr
[8]);
2016 tmp7
= GETJSAMPLE(elemptr
[7]);
2018 tmp10
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[14]);
2019 tmp11
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[13]);
2020 tmp12
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[12]);
2021 tmp13
= GETJSAMPLE(elemptr
[3]) - GETJSAMPLE(elemptr
[11]);
2022 tmp14
= GETJSAMPLE(elemptr
[4]) - GETJSAMPLE(elemptr
[10]);
2023 tmp15
= GETJSAMPLE(elemptr
[5]) - GETJSAMPLE(elemptr
[9]);
2024 tmp16
= GETJSAMPLE(elemptr
[6]) - GETJSAMPLE(elemptr
[8]);
2026 z1
= tmp0
+ tmp4
+ tmp5
;
2027 z2
= tmp1
+ tmp3
+ tmp6
;
2029 /* Apply unsigned->signed conversion */
2030 dataptr
[0] = (DCTELEM
) (z1
+ z2
+ z3
- 15 * CENTERJSAMPLE
);
2032 dataptr
[6] = (DCTELEM
)
2033 DESCALE(MULTIPLY(z1
- z3
, FIX(1.144122806)) - /* c6 */
2034 MULTIPLY(z2
- z3
, FIX(0.437016024)), /* c12 */
2036 tmp2
+= ((tmp1
+ tmp4
) >> 1) - tmp7
- tmp7
;
2037 z1
= MULTIPLY(tmp3
- tmp2
, FIX(1.531135173)) - /* c2+c14 */
2038 MULTIPLY(tmp6
- tmp2
, FIX(2.238241955)); /* c4+c8 */
2039 z2
= MULTIPLY(tmp5
- tmp2
, FIX(0.798468008)) - /* c8-c14 */
2040 MULTIPLY(tmp0
- tmp2
, FIX(0.091361227)); /* c2-c4 */
2041 z3
= MULTIPLY(tmp0
- tmp3
, FIX(1.383309603)) + /* c2 */
2042 MULTIPLY(tmp6
- tmp5
, FIX(0.946293579)) + /* c8 */
2043 MULTIPLY(tmp1
- tmp4
, FIX(0.790569415)); /* (c6+c12)/2 */
2045 dataptr
[2] = (DCTELEM
) DESCALE(z1
+ z3
, CONST_BITS
);
2046 dataptr
[4] = (DCTELEM
) DESCALE(z2
+ z3
, CONST_BITS
);
2050 tmp2
= MULTIPLY(tmp10
- tmp12
- tmp13
+ tmp15
+ tmp16
,
2051 FIX(1.224744871)); /* c5 */
2052 tmp1
= MULTIPLY(tmp10
- tmp14
- tmp15
, FIX(1.344997024)) + /* c3 */
2053 MULTIPLY(tmp11
- tmp13
- tmp16
, FIX(0.831253876)); /* c9 */
2054 tmp12
= MULTIPLY(tmp12
, FIX(1.224744871)); /* c5 */
2055 tmp4
= MULTIPLY(tmp10
- tmp16
, FIX(1.406466353)) + /* c1 */
2056 MULTIPLY(tmp11
+ tmp14
, FIX(1.344997024)) + /* c3 */
2057 MULTIPLY(tmp13
+ tmp15
, FIX(0.575212477)); /* c11 */
2058 tmp0
= MULTIPLY(tmp13
, FIX(0.475753014)) - /* c7-c11 */
2059 MULTIPLY(tmp14
, FIX(0.513743148)) + /* c3-c9 */
2060 MULTIPLY(tmp16
, FIX(1.700497885)) + tmp4
+ tmp12
; /* c1+c13 */
2061 tmp3
= MULTIPLY(tmp10
, - FIX(0.355500862)) - /* -(c1-c7) */
2062 MULTIPLY(tmp11
, FIX(2.176250899)) - /* c3+c9 */
2063 MULTIPLY(tmp15
, FIX(0.869244010)) + tmp4
- tmp12
; /* c11+c13 */
2065 dataptr
[1] = (DCTELEM
) DESCALE(tmp0
, CONST_BITS
);
2066 dataptr
[3] = (DCTELEM
) DESCALE(tmp1
, CONST_BITS
);
2067 dataptr
[5] = (DCTELEM
) DESCALE(tmp2
, CONST_BITS
);
2068 dataptr
[7] = (DCTELEM
) DESCALE(tmp3
, CONST_BITS
);
2072 if (ctr
!= DCTSIZE
) {
2075 dataptr
+= DCTSIZE
; /* advance pointer to next row */
2077 dataptr
= workspace
; /* switch pointer to extended workspace */
2080 /* Pass 2: process columns.
2081 * We leave the results scaled up by an overall factor of 8.
2082 * We must also scale the output by (8/15)**2 = 64/225, which we partially
2083 * fold into the constant multipliers and final shifting:
2084 * cK now represents sqrt(2) * cos(K*pi/30) * 256/225.
2089 for (ctr
= DCTSIZE
-1; ctr
>= 0; ctr
--) {
2092 tmp0
= dataptr
[DCTSIZE
*0] + wsptr
[DCTSIZE
*6];
2093 tmp1
= dataptr
[DCTSIZE
*1] + wsptr
[DCTSIZE
*5];
2094 tmp2
= dataptr
[DCTSIZE
*2] + wsptr
[DCTSIZE
*4];
2095 tmp3
= dataptr
[DCTSIZE
*3] + wsptr
[DCTSIZE
*3];
2096 tmp4
= dataptr
[DCTSIZE
*4] + wsptr
[DCTSIZE
*2];
2097 tmp5
= dataptr
[DCTSIZE
*5] + wsptr
[DCTSIZE
*1];
2098 tmp6
= dataptr
[DCTSIZE
*6] + wsptr
[DCTSIZE
*0];
2099 tmp7
= dataptr
[DCTSIZE
*7];
2101 tmp10
= dataptr
[DCTSIZE
*0] - wsptr
[DCTSIZE
*6];
2102 tmp11
= dataptr
[DCTSIZE
*1] - wsptr
[DCTSIZE
*5];
2103 tmp12
= dataptr
[DCTSIZE
*2] - wsptr
[DCTSIZE
*4];
2104 tmp13
= dataptr
[DCTSIZE
*3] - wsptr
[DCTSIZE
*3];
2105 tmp14
= dataptr
[DCTSIZE
*4] - wsptr
[DCTSIZE
*2];
2106 tmp15
= dataptr
[DCTSIZE
*5] - wsptr
[DCTSIZE
*1];
2107 tmp16
= dataptr
[DCTSIZE
*6] - wsptr
[DCTSIZE
*0];
2109 z1
= tmp0
+ tmp4
+ tmp5
;
2110 z2
= tmp1
+ tmp3
+ tmp6
;
2112 dataptr
[DCTSIZE
*0] = (DCTELEM
)
2113 DESCALE(MULTIPLY(z1
+ z2
+ z3
, FIX(1.137777778)), /* 256/225 */
2116 dataptr
[DCTSIZE
*6] = (DCTELEM
)
2117 DESCALE(MULTIPLY(z1
- z3
, FIX(1.301757503)) - /* c6 */
2118 MULTIPLY(z2
- z3
, FIX(0.497227121)), /* c12 */
2120 tmp2
+= ((tmp1
+ tmp4
) >> 1) - tmp7
- tmp7
;
2121 z1
= MULTIPLY(tmp3
- tmp2
, FIX(1.742091575)) - /* c2+c14 */
2122 MULTIPLY(tmp6
- tmp2
, FIX(2.546621957)); /* c4+c8 */
2123 z2
= MULTIPLY(tmp5
- tmp2
, FIX(0.908479156)) - /* c8-c14 */
2124 MULTIPLY(tmp0
- tmp2
, FIX(0.103948774)); /* c2-c4 */
2125 z3
= MULTIPLY(tmp0
- tmp3
, FIX(1.573898926)) + /* c2 */
2126 MULTIPLY(tmp6
- tmp5
, FIX(1.076671805)) + /* c8 */
2127 MULTIPLY(tmp1
- tmp4
, FIX(0.899492312)); /* (c6+c12)/2 */
2129 dataptr
[DCTSIZE
*2] = (DCTELEM
) DESCALE(z1
+ z3
, CONST_BITS
+2);
2130 dataptr
[DCTSIZE
*4] = (DCTELEM
) DESCALE(z2
+ z3
, CONST_BITS
+2);
2134 tmp2
= MULTIPLY(tmp10
- tmp12
- tmp13
+ tmp15
+ tmp16
,
2135 FIX(1.393487498)); /* c5 */
2136 tmp1
= MULTIPLY(tmp10
- tmp14
- tmp15
, FIX(1.530307725)) + /* c3 */
2137 MULTIPLY(tmp11
- tmp13
- tmp16
, FIX(0.945782187)); /* c9 */
2138 tmp12
= MULTIPLY(tmp12
, FIX(1.393487498)); /* c5 */
2139 tmp4
= MULTIPLY(tmp10
- tmp16
, FIX(1.600246161)) + /* c1 */
2140 MULTIPLY(tmp11
+ tmp14
, FIX(1.530307725)) + /* c3 */
2141 MULTIPLY(tmp13
+ tmp15
, FIX(0.654463974)); /* c11 */
2142 tmp0
= MULTIPLY(tmp13
, FIX(0.541301207)) - /* c7-c11 */
2143 MULTIPLY(tmp14
, FIX(0.584525538)) + /* c3-c9 */
2144 MULTIPLY(tmp16
, FIX(1.934788705)) + tmp4
+ tmp12
; /* c1+c13 */
2145 tmp3
= MULTIPLY(tmp10
, - FIX(0.404480980)) - /* -(c1-c7) */
2146 MULTIPLY(tmp11
, FIX(2.476089912)) - /* c3+c9 */
2147 MULTIPLY(tmp15
, FIX(0.989006518)) + tmp4
- tmp12
; /* c11+c13 */
2149 dataptr
[DCTSIZE
*1] = (DCTELEM
) DESCALE(tmp0
, CONST_BITS
+2);
2150 dataptr
[DCTSIZE
*3] = (DCTELEM
) DESCALE(tmp1
, CONST_BITS
+2);
2151 dataptr
[DCTSIZE
*5] = (DCTELEM
) DESCALE(tmp2
, CONST_BITS
+2);
2152 dataptr
[DCTSIZE
*7] = (DCTELEM
) DESCALE(tmp3
, CONST_BITS
+2);
2154 dataptr
++; /* advance pointer to next column */
2155 wsptr
++; /* advance pointer to next column */
2161 * Perform the forward DCT on a 16x16 sample block.
2165 jpeg_fdct_16x16 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
2167 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
, tmp5
, tmp6
, tmp7
;
2168 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
, tmp15
, tmp16
, tmp17
;
2169 DCTELEM workspace
[DCTSIZE2
];
2176 /* Pass 1: process rows. */
2177 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
2178 /* furthermore, we scale the results by 2**PASS1_BITS. */
2179 /* cK represents sqrt(2) * cos(K*pi/32). */
2184 elemptr
= sample_data
[ctr
] + start_col
;
2188 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[15]);
2189 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[14]);
2190 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[13]);
2191 tmp3
= GETJSAMPLE(elemptr
[3]) + GETJSAMPLE(elemptr
[12]);
2192 tmp4
= GETJSAMPLE(elemptr
[4]) + GETJSAMPLE(elemptr
[11]);
2193 tmp5
= GETJSAMPLE(elemptr
[5]) + GETJSAMPLE(elemptr
[10]);
2194 tmp6
= GETJSAMPLE(elemptr
[6]) + GETJSAMPLE(elemptr
[9]);
2195 tmp7
= GETJSAMPLE(elemptr
[7]) + GETJSAMPLE(elemptr
[8]);
2197 tmp10
= tmp0
+ tmp7
;
2198 tmp14
= tmp0
- tmp7
;
2199 tmp11
= tmp1
+ tmp6
;
2200 tmp15
= tmp1
- tmp6
;
2201 tmp12
= tmp2
+ tmp5
;
2202 tmp16
= tmp2
- tmp5
;
2203 tmp13
= tmp3
+ tmp4
;
2204 tmp17
= tmp3
- tmp4
;
2206 tmp0
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[15]);
2207 tmp1
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[14]);
2208 tmp2
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[13]);
2209 tmp3
= GETJSAMPLE(elemptr
[3]) - GETJSAMPLE(elemptr
[12]);
2210 tmp4
= GETJSAMPLE(elemptr
[4]) - GETJSAMPLE(elemptr
[11]);
2211 tmp5
= GETJSAMPLE(elemptr
[5]) - GETJSAMPLE(elemptr
[10]);
2212 tmp6
= GETJSAMPLE(elemptr
[6]) - GETJSAMPLE(elemptr
[9]);
2213 tmp7
= GETJSAMPLE(elemptr
[7]) - GETJSAMPLE(elemptr
[8]);
2215 /* Apply unsigned->signed conversion */
2216 dataptr
[0] = (DCTELEM
)
2217 ((tmp10
+ tmp11
+ tmp12
+ tmp13
- 16 * CENTERJSAMPLE
) << PASS1_BITS
);
2218 dataptr
[4] = (DCTELEM
)
2219 DESCALE(MULTIPLY(tmp10
- tmp13
, FIX(1.306562965)) + /* c4[16] = c2[8] */
2220 MULTIPLY(tmp11
- tmp12
, FIX_0_541196100
), /* c12[16] = c6[8] */
2221 CONST_BITS
-PASS1_BITS
);
2223 tmp10
= MULTIPLY(tmp17
- tmp15
, FIX(0.275899379)) + /* c14[16] = c7[8] */
2224 MULTIPLY(tmp14
- tmp16
, FIX(1.387039845)); /* c2[16] = c1[8] */
2226 dataptr
[2] = (DCTELEM
)
2227 DESCALE(tmp10
+ MULTIPLY(tmp15
, FIX(1.451774982)) /* c6+c14 */
2228 + MULTIPLY(tmp16
, FIX(2.172734804)), /* c2+c10 */
2229 CONST_BITS
-PASS1_BITS
);
2230 dataptr
[6] = (DCTELEM
)
2231 DESCALE(tmp10
- MULTIPLY(tmp14
, FIX(0.211164243)) /* c2-c6 */
2232 - MULTIPLY(tmp17
, FIX(1.061594338)), /* c10+c14 */
2233 CONST_BITS
-PASS1_BITS
);
2237 tmp11
= MULTIPLY(tmp0
+ tmp1
, FIX(1.353318001)) + /* c3 */
2238 MULTIPLY(tmp6
- tmp7
, FIX(0.410524528)); /* c13 */
2239 tmp12
= MULTIPLY(tmp0
+ tmp2
, FIX(1.247225013)) + /* c5 */
2240 MULTIPLY(tmp5
+ tmp7
, FIX(0.666655658)); /* c11 */
2241 tmp13
= MULTIPLY(tmp0
+ tmp3
, FIX(1.093201867)) + /* c7 */
2242 MULTIPLY(tmp4
- tmp7
, FIX(0.897167586)); /* c9 */
2243 tmp14
= MULTIPLY(tmp1
+ tmp2
, FIX(0.138617169)) + /* c15 */
2244 MULTIPLY(tmp6
- tmp5
, FIX(1.407403738)); /* c1 */
2245 tmp15
= MULTIPLY(tmp1
+ tmp3
, - FIX(0.666655658)) + /* -c11 */
2246 MULTIPLY(tmp4
+ tmp6
, - FIX(1.247225013)); /* -c5 */
2247 tmp16
= MULTIPLY(tmp2
+ tmp3
, - FIX(1.353318001)) + /* -c3 */
2248 MULTIPLY(tmp5
- tmp4
, FIX(0.410524528)); /* c13 */
2249 tmp10
= tmp11
+ tmp12
+ tmp13
-
2250 MULTIPLY(tmp0
, FIX(2.286341144)) + /* c7+c5+c3-c1 */
2251 MULTIPLY(tmp7
, FIX(0.779653625)); /* c15+c13-c11+c9 */
2252 tmp11
+= tmp14
+ tmp15
+ MULTIPLY(tmp1
, FIX(0.071888074)) /* c9-c3-c15+c11 */
2253 - MULTIPLY(tmp6
, FIX(1.663905119)); /* c7+c13+c1-c5 */
2254 tmp12
+= tmp14
+ tmp16
- MULTIPLY(tmp2
, FIX(1.125726048)) /* c7+c5+c15-c3 */
2255 + MULTIPLY(tmp5
, FIX(1.227391138)); /* c9-c11+c1-c13 */
2256 tmp13
+= tmp15
+ tmp16
+ MULTIPLY(tmp3
, FIX(1.065388962)) /* c15+c3+c11-c7 */
2257 + MULTIPLY(tmp4
, FIX(2.167985692)); /* c1+c13+c5-c9 */
2259 dataptr
[1] = (DCTELEM
) DESCALE(tmp10
, CONST_BITS
-PASS1_BITS
);
2260 dataptr
[3] = (DCTELEM
) DESCALE(tmp11
, CONST_BITS
-PASS1_BITS
);
2261 dataptr
[5] = (DCTELEM
) DESCALE(tmp12
, CONST_BITS
-PASS1_BITS
);
2262 dataptr
[7] = (DCTELEM
) DESCALE(tmp13
, CONST_BITS
-PASS1_BITS
);
2266 if (ctr
!= DCTSIZE
) {
2267 if (ctr
== DCTSIZE
* 2)
2269 dataptr
+= DCTSIZE
; /* advance pointer to next row */
2271 dataptr
= workspace
; /* switch pointer to extended workspace */
2274 /* Pass 2: process columns.
2275 * We remove the PASS1_BITS scaling, but leave the results scaled up
2276 * by an overall factor of 8.
2277 * We must also scale the output by (8/16)**2 = 1/2**2.
2282 for (ctr
= DCTSIZE
-1; ctr
>= 0; ctr
--) {
2285 tmp0
= dataptr
[DCTSIZE
*0] + wsptr
[DCTSIZE
*7];
2286 tmp1
= dataptr
[DCTSIZE
*1] + wsptr
[DCTSIZE
*6];
2287 tmp2
= dataptr
[DCTSIZE
*2] + wsptr
[DCTSIZE
*5];
2288 tmp3
= dataptr
[DCTSIZE
*3] + wsptr
[DCTSIZE
*4];
2289 tmp4
= dataptr
[DCTSIZE
*4] + wsptr
[DCTSIZE
*3];
2290 tmp5
= dataptr
[DCTSIZE
*5] + wsptr
[DCTSIZE
*2];
2291 tmp6
= dataptr
[DCTSIZE
*6] + wsptr
[DCTSIZE
*1];
2292 tmp7
= dataptr
[DCTSIZE
*7] + wsptr
[DCTSIZE
*0];
2294 tmp10
= tmp0
+ tmp7
;
2295 tmp14
= tmp0
- tmp7
;
2296 tmp11
= tmp1
+ tmp6
;
2297 tmp15
= tmp1
- tmp6
;
2298 tmp12
= tmp2
+ tmp5
;
2299 tmp16
= tmp2
- tmp5
;
2300 tmp13
= tmp3
+ tmp4
;
2301 tmp17
= tmp3
- tmp4
;
2303 tmp0
= dataptr
[DCTSIZE
*0] - wsptr
[DCTSIZE
*7];
2304 tmp1
= dataptr
[DCTSIZE
*1] - wsptr
[DCTSIZE
*6];
2305 tmp2
= dataptr
[DCTSIZE
*2] - wsptr
[DCTSIZE
*5];
2306 tmp3
= dataptr
[DCTSIZE
*3] - wsptr
[DCTSIZE
*4];
2307 tmp4
= dataptr
[DCTSIZE
*4] - wsptr
[DCTSIZE
*3];
2308 tmp5
= dataptr
[DCTSIZE
*5] - wsptr
[DCTSIZE
*2];
2309 tmp6
= dataptr
[DCTSIZE
*6] - wsptr
[DCTSIZE
*1];
2310 tmp7
= dataptr
[DCTSIZE
*7] - wsptr
[DCTSIZE
*0];
2312 dataptr
[DCTSIZE
*0] = (DCTELEM
)
2313 DESCALE(tmp10
+ tmp11
+ tmp12
+ tmp13
, PASS1_BITS
+2);
2314 dataptr
[DCTSIZE
*4] = (DCTELEM
)
2315 DESCALE(MULTIPLY(tmp10
- tmp13
, FIX(1.306562965)) + /* c4[16] = c2[8] */
2316 MULTIPLY(tmp11
- tmp12
, FIX_0_541196100
), /* c12[16] = c6[8] */
2317 CONST_BITS
+PASS1_BITS
+2);
2319 tmp10
= MULTIPLY(tmp17
- tmp15
, FIX(0.275899379)) + /* c14[16] = c7[8] */
2320 MULTIPLY(tmp14
- tmp16
, FIX(1.387039845)); /* c2[16] = c1[8] */
2322 dataptr
[DCTSIZE
*2] = (DCTELEM
)
2323 DESCALE(tmp10
+ MULTIPLY(tmp15
, FIX(1.451774982)) /* c6+c14 */
2324 + MULTIPLY(tmp16
, FIX(2.172734804)), /* c2+10 */
2325 CONST_BITS
+PASS1_BITS
+2);
2326 dataptr
[DCTSIZE
*6] = (DCTELEM
)
2327 DESCALE(tmp10
- MULTIPLY(tmp14
, FIX(0.211164243)) /* c2-c6 */
2328 - MULTIPLY(tmp17
, FIX(1.061594338)), /* c10+c14 */
2329 CONST_BITS
+PASS1_BITS
+2);
2333 tmp11
= MULTIPLY(tmp0
+ tmp1
, FIX(1.353318001)) + /* c3 */
2334 MULTIPLY(tmp6
- tmp7
, FIX(0.410524528)); /* c13 */
2335 tmp12
= MULTIPLY(tmp0
+ tmp2
, FIX(1.247225013)) + /* c5 */
2336 MULTIPLY(tmp5
+ tmp7
, FIX(0.666655658)); /* c11 */
2337 tmp13
= MULTIPLY(tmp0
+ tmp3
, FIX(1.093201867)) + /* c7 */
2338 MULTIPLY(tmp4
- tmp7
, FIX(0.897167586)); /* c9 */
2339 tmp14
= MULTIPLY(tmp1
+ tmp2
, FIX(0.138617169)) + /* c15 */
2340 MULTIPLY(tmp6
- tmp5
, FIX(1.407403738)); /* c1 */
2341 tmp15
= MULTIPLY(tmp1
+ tmp3
, - FIX(0.666655658)) + /* -c11 */
2342 MULTIPLY(tmp4
+ tmp6
, - FIX(1.247225013)); /* -c5 */
2343 tmp16
= MULTIPLY(tmp2
+ tmp3
, - FIX(1.353318001)) + /* -c3 */
2344 MULTIPLY(tmp5
- tmp4
, FIX(0.410524528)); /* c13 */
2345 tmp10
= tmp11
+ tmp12
+ tmp13
-
2346 MULTIPLY(tmp0
, FIX(2.286341144)) + /* c7+c5+c3-c1 */
2347 MULTIPLY(tmp7
, FIX(0.779653625)); /* c15+c13-c11+c9 */
2348 tmp11
+= tmp14
+ tmp15
+ MULTIPLY(tmp1
, FIX(0.071888074)) /* c9-c3-c15+c11 */
2349 - MULTIPLY(tmp6
, FIX(1.663905119)); /* c7+c13+c1-c5 */
2350 tmp12
+= tmp14
+ tmp16
- MULTIPLY(tmp2
, FIX(1.125726048)) /* c7+c5+c15-c3 */
2351 + MULTIPLY(tmp5
, FIX(1.227391138)); /* c9-c11+c1-c13 */
2352 tmp13
+= tmp15
+ tmp16
+ MULTIPLY(tmp3
, FIX(1.065388962)) /* c15+c3+c11-c7 */
2353 + MULTIPLY(tmp4
, FIX(2.167985692)); /* c1+c13+c5-c9 */
2355 dataptr
[DCTSIZE
*1] = (DCTELEM
) DESCALE(tmp10
, CONST_BITS
+PASS1_BITS
+2);
2356 dataptr
[DCTSIZE
*3] = (DCTELEM
) DESCALE(tmp11
, CONST_BITS
+PASS1_BITS
+2);
2357 dataptr
[DCTSIZE
*5] = (DCTELEM
) DESCALE(tmp12
, CONST_BITS
+PASS1_BITS
+2);
2358 dataptr
[DCTSIZE
*7] = (DCTELEM
) DESCALE(tmp13
, CONST_BITS
+PASS1_BITS
+2);
2360 dataptr
++; /* advance pointer to next column */
2361 wsptr
++; /* advance pointer to next column */
2367 * Perform the forward DCT on a 16x8 sample block.
2369 * 16-point FDCT in pass 1 (rows), 8-point in pass 2 (columns).
2373 jpeg_fdct_16x8 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
2375 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
, tmp5
, tmp6
, tmp7
;
2376 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
, tmp15
, tmp16
, tmp17
;
2383 /* Pass 1: process rows. */
2384 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
2385 /* furthermore, we scale the results by 2**PASS1_BITS. */
2386 /* 16-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/32). */
2390 for (ctr
= 0; ctr
< DCTSIZE
; ctr
++) {
2391 elemptr
= sample_data
[ctr
] + start_col
;
2395 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[15]);
2396 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[14]);
2397 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[13]);
2398 tmp3
= GETJSAMPLE(elemptr
[3]) + GETJSAMPLE(elemptr
[12]);
2399 tmp4
= GETJSAMPLE(elemptr
[4]) + GETJSAMPLE(elemptr
[11]);
2400 tmp5
= GETJSAMPLE(elemptr
[5]) + GETJSAMPLE(elemptr
[10]);
2401 tmp6
= GETJSAMPLE(elemptr
[6]) + GETJSAMPLE(elemptr
[9]);
2402 tmp7
= GETJSAMPLE(elemptr
[7]) + GETJSAMPLE(elemptr
[8]);
2404 tmp10
= tmp0
+ tmp7
;
2405 tmp14
= tmp0
- tmp7
;
2406 tmp11
= tmp1
+ tmp6
;
2407 tmp15
= tmp1
- tmp6
;
2408 tmp12
= tmp2
+ tmp5
;
2409 tmp16
= tmp2
- tmp5
;
2410 tmp13
= tmp3
+ tmp4
;
2411 tmp17
= tmp3
- tmp4
;
2413 tmp0
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[15]);
2414 tmp1
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[14]);
2415 tmp2
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[13]);
2416 tmp3
= GETJSAMPLE(elemptr
[3]) - GETJSAMPLE(elemptr
[12]);
2417 tmp4
= GETJSAMPLE(elemptr
[4]) - GETJSAMPLE(elemptr
[11]);
2418 tmp5
= GETJSAMPLE(elemptr
[5]) - GETJSAMPLE(elemptr
[10]);
2419 tmp6
= GETJSAMPLE(elemptr
[6]) - GETJSAMPLE(elemptr
[9]);
2420 tmp7
= GETJSAMPLE(elemptr
[7]) - GETJSAMPLE(elemptr
[8]);
2422 /* Apply unsigned->signed conversion */
2423 dataptr
[0] = (DCTELEM
)
2424 ((tmp10
+ tmp11
+ tmp12
+ tmp13
- 16 * CENTERJSAMPLE
) << PASS1_BITS
);
2425 dataptr
[4] = (DCTELEM
)
2426 DESCALE(MULTIPLY(tmp10
- tmp13
, FIX(1.306562965)) + /* c4[16] = c2[8] */
2427 MULTIPLY(tmp11
- tmp12
, FIX_0_541196100
), /* c12[16] = c6[8] */
2428 CONST_BITS
-PASS1_BITS
);
2430 tmp10
= MULTIPLY(tmp17
- tmp15
, FIX(0.275899379)) + /* c14[16] = c7[8] */
2431 MULTIPLY(tmp14
- tmp16
, FIX(1.387039845)); /* c2[16] = c1[8] */
2433 dataptr
[2] = (DCTELEM
)
2434 DESCALE(tmp10
+ MULTIPLY(tmp15
, FIX(1.451774982)) /* c6+c14 */
2435 + MULTIPLY(tmp16
, FIX(2.172734804)), /* c2+c10 */
2436 CONST_BITS
-PASS1_BITS
);
2437 dataptr
[6] = (DCTELEM
)
2438 DESCALE(tmp10
- MULTIPLY(tmp14
, FIX(0.211164243)) /* c2-c6 */
2439 - MULTIPLY(tmp17
, FIX(1.061594338)), /* c10+c14 */
2440 CONST_BITS
-PASS1_BITS
);
2444 tmp11
= MULTIPLY(tmp0
+ tmp1
, FIX(1.353318001)) + /* c3 */
2445 MULTIPLY(tmp6
- tmp7
, FIX(0.410524528)); /* c13 */
2446 tmp12
= MULTIPLY(tmp0
+ tmp2
, FIX(1.247225013)) + /* c5 */
2447 MULTIPLY(tmp5
+ tmp7
, FIX(0.666655658)); /* c11 */
2448 tmp13
= MULTIPLY(tmp0
+ tmp3
, FIX(1.093201867)) + /* c7 */
2449 MULTIPLY(tmp4
- tmp7
, FIX(0.897167586)); /* c9 */
2450 tmp14
= MULTIPLY(tmp1
+ tmp2
, FIX(0.138617169)) + /* c15 */
2451 MULTIPLY(tmp6
- tmp5
, FIX(1.407403738)); /* c1 */
2452 tmp15
= MULTIPLY(tmp1
+ tmp3
, - FIX(0.666655658)) + /* -c11 */
2453 MULTIPLY(tmp4
+ tmp6
, - FIX(1.247225013)); /* -c5 */
2454 tmp16
= MULTIPLY(tmp2
+ tmp3
, - FIX(1.353318001)) + /* -c3 */
2455 MULTIPLY(tmp5
- tmp4
, FIX(0.410524528)); /* c13 */
2456 tmp10
= tmp11
+ tmp12
+ tmp13
-
2457 MULTIPLY(tmp0
, FIX(2.286341144)) + /* c7+c5+c3-c1 */
2458 MULTIPLY(tmp7
, FIX(0.779653625)); /* c15+c13-c11+c9 */
2459 tmp11
+= tmp14
+ tmp15
+ MULTIPLY(tmp1
, FIX(0.071888074)) /* c9-c3-c15+c11 */
2460 - MULTIPLY(tmp6
, FIX(1.663905119)); /* c7+c13+c1-c5 */
2461 tmp12
+= tmp14
+ tmp16
- MULTIPLY(tmp2
, FIX(1.125726048)) /* c7+c5+c15-c3 */
2462 + MULTIPLY(tmp5
, FIX(1.227391138)); /* c9-c11+c1-c13 */
2463 tmp13
+= tmp15
+ tmp16
+ MULTIPLY(tmp3
, FIX(1.065388962)) /* c15+c3+c11-c7 */
2464 + MULTIPLY(tmp4
, FIX(2.167985692)); /* c1+c13+c5-c9 */
2466 dataptr
[1] = (DCTELEM
) DESCALE(tmp10
, CONST_BITS
-PASS1_BITS
);
2467 dataptr
[3] = (DCTELEM
) DESCALE(tmp11
, CONST_BITS
-PASS1_BITS
);
2468 dataptr
[5] = (DCTELEM
) DESCALE(tmp12
, CONST_BITS
-PASS1_BITS
);
2469 dataptr
[7] = (DCTELEM
) DESCALE(tmp13
, CONST_BITS
-PASS1_BITS
);
2471 dataptr
+= DCTSIZE
; /* advance pointer to next row */
2474 /* Pass 2: process columns.
2475 * We remove the PASS1_BITS scaling, but leave the results scaled up
2476 * by an overall factor of 8.
2477 * We must also scale the output by 8/16 = 1/2.
2481 for (ctr
= DCTSIZE
-1; ctr
>= 0; ctr
--) {
2482 /* Even part per LL&M figure 1 --- note that published figure is faulty;
2483 * rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
2486 tmp0
= dataptr
[DCTSIZE
*0] + dataptr
[DCTSIZE
*7];
2487 tmp1
= dataptr
[DCTSIZE
*1] + dataptr
[DCTSIZE
*6];
2488 tmp2
= dataptr
[DCTSIZE
*2] + dataptr
[DCTSIZE
*5];
2489 tmp3
= dataptr
[DCTSIZE
*3] + dataptr
[DCTSIZE
*4];
2491 tmp10
= tmp0
+ tmp3
;
2492 tmp12
= tmp0
- tmp3
;
2493 tmp11
= tmp1
+ tmp2
;
2494 tmp13
= tmp1
- tmp2
;
2496 tmp0
= dataptr
[DCTSIZE
*0] - dataptr
[DCTSIZE
*7];
2497 tmp1
= dataptr
[DCTSIZE
*1] - dataptr
[DCTSIZE
*6];
2498 tmp2
= dataptr
[DCTSIZE
*2] - dataptr
[DCTSIZE
*5];
2499 tmp3
= dataptr
[DCTSIZE
*3] - dataptr
[DCTSIZE
*4];
2501 dataptr
[DCTSIZE
*0] = (DCTELEM
) DESCALE(tmp10
+ tmp11
, PASS1_BITS
+1);
2502 dataptr
[DCTSIZE
*4] = (DCTELEM
) DESCALE(tmp10
- tmp11
, PASS1_BITS
+1);
2504 z1
= MULTIPLY(tmp12
+ tmp13
, FIX_0_541196100
);
2505 dataptr
[DCTSIZE
*2] = (DCTELEM
) DESCALE(z1
+ MULTIPLY(tmp12
, FIX_0_765366865
),
2506 CONST_BITS
+PASS1_BITS
+1);
2507 dataptr
[DCTSIZE
*6] = (DCTELEM
) DESCALE(z1
- MULTIPLY(tmp13
, FIX_1_847759065
),
2508 CONST_BITS
+PASS1_BITS
+1);
2510 /* Odd part per figure 8 --- note paper omits factor of sqrt(2).
2511 * 8-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
2512 * i0..i3 in the paper are tmp0..tmp3 here.
2515 tmp10
= tmp0
+ tmp3
;
2516 tmp11
= tmp1
+ tmp2
;
2517 tmp12
= tmp0
+ tmp2
;
2518 tmp13
= tmp1
+ tmp3
;
2519 z1
= MULTIPLY(tmp12
+ tmp13
, FIX_1_175875602
); /* c3 */
2521 tmp0
= MULTIPLY(tmp0
, FIX_1_501321110
); /* c1+c3-c5-c7 */
2522 tmp1
= MULTIPLY(tmp1
, FIX_3_072711026
); /* c1+c3+c5-c7 */
2523 tmp2
= MULTIPLY(tmp2
, FIX_2_053119869
); /* c1+c3-c5+c7 */
2524 tmp3
= MULTIPLY(tmp3
, FIX_0_298631336
); /* -c1+c3+c5-c7 */
2525 tmp10
= MULTIPLY(tmp10
, - FIX_0_899976223
); /* c7-c3 */
2526 tmp11
= MULTIPLY(tmp11
, - FIX_2_562915447
); /* -c1-c3 */
2527 tmp12
= MULTIPLY(tmp12
, - FIX_0_390180644
); /* c5-c3 */
2528 tmp13
= MULTIPLY(tmp13
, - FIX_1_961570560
); /* -c3-c5 */
2533 dataptr
[DCTSIZE
*1] = (DCTELEM
) DESCALE(tmp0
+ tmp10
+ tmp12
,
2534 CONST_BITS
+PASS1_BITS
+1);
2535 dataptr
[DCTSIZE
*3] = (DCTELEM
) DESCALE(tmp1
+ tmp11
+ tmp13
,
2536 CONST_BITS
+PASS1_BITS
+1);
2537 dataptr
[DCTSIZE
*5] = (DCTELEM
) DESCALE(tmp2
+ tmp11
+ tmp12
,
2538 CONST_BITS
+PASS1_BITS
+1);
2539 dataptr
[DCTSIZE
*7] = (DCTELEM
) DESCALE(tmp3
+ tmp10
+ tmp13
,
2540 CONST_BITS
+PASS1_BITS
+1);
2542 dataptr
++; /* advance pointer to next column */
2548 * Perform the forward DCT on a 14x7 sample block.
2550 * 14-point FDCT in pass 1 (rows), 7-point in pass 2 (columns).
2554 jpeg_fdct_14x7 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
2556 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
, tmp5
, tmp6
;
2557 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
, tmp15
, tmp16
;
2564 /* Zero bottom row of output coefficient block. */
2565 MEMZERO(&data
[DCTSIZE
*7], SIZEOF(DCTELEM
) * DCTSIZE
);
2567 /* Pass 1: process rows. */
2568 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
2569 /* furthermore, we scale the results by 2**PASS1_BITS. */
2570 /* 14-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/28). */
2573 for (ctr
= 0; ctr
< 7; ctr
++) {
2574 elemptr
= sample_data
[ctr
] + start_col
;
2578 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[13]);
2579 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[12]);
2580 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[11]);
2581 tmp13
= GETJSAMPLE(elemptr
[3]) + GETJSAMPLE(elemptr
[10]);
2582 tmp4
= GETJSAMPLE(elemptr
[4]) + GETJSAMPLE(elemptr
[9]);
2583 tmp5
= GETJSAMPLE(elemptr
[5]) + GETJSAMPLE(elemptr
[8]);
2584 tmp6
= GETJSAMPLE(elemptr
[6]) + GETJSAMPLE(elemptr
[7]);
2586 tmp10
= tmp0
+ tmp6
;
2587 tmp14
= tmp0
- tmp6
;
2588 tmp11
= tmp1
+ tmp5
;
2589 tmp15
= tmp1
- tmp5
;
2590 tmp12
= tmp2
+ tmp4
;
2591 tmp16
= tmp2
- tmp4
;
2593 tmp0
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[13]);
2594 tmp1
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[12]);
2595 tmp2
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[11]);
2596 tmp3
= GETJSAMPLE(elemptr
[3]) - GETJSAMPLE(elemptr
[10]);
2597 tmp4
= GETJSAMPLE(elemptr
[4]) - GETJSAMPLE(elemptr
[9]);
2598 tmp5
= GETJSAMPLE(elemptr
[5]) - GETJSAMPLE(elemptr
[8]);
2599 tmp6
= GETJSAMPLE(elemptr
[6]) - GETJSAMPLE(elemptr
[7]);
2601 /* Apply unsigned->signed conversion */
2602 dataptr
[0] = (DCTELEM
)
2603 ((tmp10
+ tmp11
+ tmp12
+ tmp13
- 14 * CENTERJSAMPLE
) << PASS1_BITS
);
2605 dataptr
[4] = (DCTELEM
)
2606 DESCALE(MULTIPLY(tmp10
- tmp13
, FIX(1.274162392)) + /* c4 */
2607 MULTIPLY(tmp11
- tmp13
, FIX(0.314692123)) - /* c12 */
2608 MULTIPLY(tmp12
- tmp13
, FIX(0.881747734)), /* c8 */
2609 CONST_BITS
-PASS1_BITS
);
2611 tmp10
= MULTIPLY(tmp14
+ tmp15
, FIX(1.105676686)); /* c6 */
2613 dataptr
[2] = (DCTELEM
)
2614 DESCALE(tmp10
+ MULTIPLY(tmp14
, FIX(0.273079590)) /* c2-c6 */
2615 + MULTIPLY(tmp16
, FIX(0.613604268)), /* c10 */
2616 CONST_BITS
-PASS1_BITS
);
2617 dataptr
[6] = (DCTELEM
)
2618 DESCALE(tmp10
- MULTIPLY(tmp15
, FIX(1.719280954)) /* c6+c10 */
2619 - MULTIPLY(tmp16
, FIX(1.378756276)), /* c2 */
2620 CONST_BITS
-PASS1_BITS
);
2624 tmp10
= tmp1
+ tmp2
;
2625 tmp11
= tmp5
- tmp4
;
2626 dataptr
[7] = (DCTELEM
) ((tmp0
- tmp10
+ tmp3
- tmp11
- tmp6
) << PASS1_BITS
);
2627 tmp3
<<= CONST_BITS
;
2628 tmp10
= MULTIPLY(tmp10
, - FIX(0.158341681)); /* -c13 */
2629 tmp11
= MULTIPLY(tmp11
, FIX(1.405321284)); /* c1 */
2630 tmp10
+= tmp11
- tmp3
;
2631 tmp11
= MULTIPLY(tmp0
+ tmp2
, FIX(1.197448846)) + /* c5 */
2632 MULTIPLY(tmp4
+ tmp6
, FIX(0.752406978)); /* c9 */
2633 dataptr
[5] = (DCTELEM
)
2634 DESCALE(tmp10
+ tmp11
- MULTIPLY(tmp2
, FIX(2.373959773)) /* c3+c5-c13 */
2635 + MULTIPLY(tmp4
, FIX(1.119999435)), /* c1+c11-c9 */
2636 CONST_BITS
-PASS1_BITS
);
2637 tmp12
= MULTIPLY(tmp0
+ tmp1
, FIX(1.334852607)) + /* c3 */
2638 MULTIPLY(tmp5
- tmp6
, FIX(0.467085129)); /* c11 */
2639 dataptr
[3] = (DCTELEM
)
2640 DESCALE(tmp10
+ tmp12
- MULTIPLY(tmp1
, FIX(0.424103948)) /* c3-c9-c13 */
2641 - MULTIPLY(tmp5
, FIX(3.069855259)), /* c1+c5+c11 */
2642 CONST_BITS
-PASS1_BITS
);
2643 dataptr
[1] = (DCTELEM
)
2644 DESCALE(tmp11
+ tmp12
+ tmp3
+ tmp6
-
2645 MULTIPLY(tmp0
+ tmp6
, FIX(1.126980169)), /* c3+c5-c1 */
2646 CONST_BITS
-PASS1_BITS
);
2648 dataptr
+= DCTSIZE
; /* advance pointer to next row */
2651 /* Pass 2: process columns.
2652 * We remove the PASS1_BITS scaling, but leave the results scaled up
2653 * by an overall factor of 8.
2654 * We must also scale the output by (8/14)*(8/7) = 32/49, which we
2655 * partially fold into the constant multipliers and final shifting:
2656 * 7-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/14) * 64/49.
2660 for (ctr
= DCTSIZE
-1; ctr
>= 0; ctr
--) {
2663 tmp0
= dataptr
[DCTSIZE
*0] + dataptr
[DCTSIZE
*6];
2664 tmp1
= dataptr
[DCTSIZE
*1] + dataptr
[DCTSIZE
*5];
2665 tmp2
= dataptr
[DCTSIZE
*2] + dataptr
[DCTSIZE
*4];
2666 tmp3
= dataptr
[DCTSIZE
*3];
2668 tmp10
= dataptr
[DCTSIZE
*0] - dataptr
[DCTSIZE
*6];
2669 tmp11
= dataptr
[DCTSIZE
*1] - dataptr
[DCTSIZE
*5];
2670 tmp12
= dataptr
[DCTSIZE
*2] - dataptr
[DCTSIZE
*4];
2673 dataptr
[DCTSIZE
*0] = (DCTELEM
)
2674 DESCALE(MULTIPLY(z1
+ tmp1
+ tmp3
, FIX(1.306122449)), /* 64/49 */
2675 CONST_BITS
+PASS1_BITS
+1);
2679 z1
= MULTIPLY(z1
, FIX(0.461784020)); /* (c2+c6-c4)/2 */
2680 z2
= MULTIPLY(tmp0
- tmp2
, FIX(1.202428084)); /* (c2+c4-c6)/2 */
2681 z3
= MULTIPLY(tmp1
- tmp2
, FIX(0.411026446)); /* c6 */
2682 dataptr
[DCTSIZE
*2] = (DCTELEM
) DESCALE(z1
+ z2
+ z3
, CONST_BITS
+PASS1_BITS
+1);
2684 z2
= MULTIPLY(tmp0
- tmp1
, FIX(1.151670509)); /* c4 */
2685 dataptr
[DCTSIZE
*4] = (DCTELEM
)
2686 DESCALE(z2
+ z3
- MULTIPLY(tmp1
- tmp3
, FIX(0.923568041)), /* c2+c6-c4 */
2687 CONST_BITS
+PASS1_BITS
+1);
2688 dataptr
[DCTSIZE
*6] = (DCTELEM
) DESCALE(z1
+ z2
, CONST_BITS
+PASS1_BITS
+1);
2692 tmp1
= MULTIPLY(tmp10
+ tmp11
, FIX(1.221765677)); /* (c3+c1-c5)/2 */
2693 tmp2
= MULTIPLY(tmp10
- tmp11
, FIX(0.222383464)); /* (c3+c5-c1)/2 */
2696 tmp2
= MULTIPLY(tmp11
+ tmp12
, - FIX(1.800824523)); /* -c1 */
2698 tmp3
= MULTIPLY(tmp10
+ tmp12
, FIX(0.801442310)); /* c5 */
2700 tmp2
+= tmp3
+ MULTIPLY(tmp12
, FIX(2.443531355)); /* c3+c1-c5 */
2702 dataptr
[DCTSIZE
*1] = (DCTELEM
) DESCALE(tmp0
, CONST_BITS
+PASS1_BITS
+1);
2703 dataptr
[DCTSIZE
*3] = (DCTELEM
) DESCALE(tmp1
, CONST_BITS
+PASS1_BITS
+1);
2704 dataptr
[DCTSIZE
*5] = (DCTELEM
) DESCALE(tmp2
, CONST_BITS
+PASS1_BITS
+1);
2706 dataptr
++; /* advance pointer to next column */
2712 * Perform the forward DCT on a 12x6 sample block.
2714 * 12-point FDCT in pass 1 (rows), 6-point in pass 2 (columns).
2718 jpeg_fdct_12x6 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
2720 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
, tmp5
;
2721 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
, tmp15
;
2727 /* Zero 2 bottom rows of output coefficient block. */
2728 MEMZERO(&data
[DCTSIZE
*6], SIZEOF(DCTELEM
) * DCTSIZE
* 2);
2730 /* Pass 1: process rows. */
2731 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
2732 /* furthermore, we scale the results by 2**PASS1_BITS. */
2733 /* 12-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/24). */
2736 for (ctr
= 0; ctr
< 6; ctr
++) {
2737 elemptr
= sample_data
[ctr
] + start_col
;
2741 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[11]);
2742 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[10]);
2743 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[9]);
2744 tmp3
= GETJSAMPLE(elemptr
[3]) + GETJSAMPLE(elemptr
[8]);
2745 tmp4
= GETJSAMPLE(elemptr
[4]) + GETJSAMPLE(elemptr
[7]);
2746 tmp5
= GETJSAMPLE(elemptr
[5]) + GETJSAMPLE(elemptr
[6]);
2748 tmp10
= tmp0
+ tmp5
;
2749 tmp13
= tmp0
- tmp5
;
2750 tmp11
= tmp1
+ tmp4
;
2751 tmp14
= tmp1
- tmp4
;
2752 tmp12
= tmp2
+ tmp3
;
2753 tmp15
= tmp2
- tmp3
;
2755 tmp0
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[11]);
2756 tmp1
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[10]);
2757 tmp2
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[9]);
2758 tmp3
= GETJSAMPLE(elemptr
[3]) - GETJSAMPLE(elemptr
[8]);
2759 tmp4
= GETJSAMPLE(elemptr
[4]) - GETJSAMPLE(elemptr
[7]);
2760 tmp5
= GETJSAMPLE(elemptr
[5]) - GETJSAMPLE(elemptr
[6]);
2762 /* Apply unsigned->signed conversion */
2763 dataptr
[0] = (DCTELEM
)
2764 ((tmp10
+ tmp11
+ tmp12
- 12 * CENTERJSAMPLE
) << PASS1_BITS
);
2765 dataptr
[6] = (DCTELEM
) ((tmp13
- tmp14
- tmp15
) << PASS1_BITS
);
2766 dataptr
[4] = (DCTELEM
)
2767 DESCALE(MULTIPLY(tmp10
- tmp12
, FIX(1.224744871)), /* c4 */
2768 CONST_BITS
-PASS1_BITS
);
2769 dataptr
[2] = (DCTELEM
)
2770 DESCALE(tmp14
- tmp15
+ MULTIPLY(tmp13
+ tmp15
, FIX(1.366025404)), /* c2 */
2771 CONST_BITS
-PASS1_BITS
);
2775 tmp10
= MULTIPLY(tmp1
+ tmp4
, FIX_0_541196100
); /* c9 */
2776 tmp14
= tmp10
+ MULTIPLY(tmp1
, FIX_0_765366865
); /* c3-c9 */
2777 tmp15
= tmp10
- MULTIPLY(tmp4
, FIX_1_847759065
); /* c3+c9 */
2778 tmp12
= MULTIPLY(tmp0
+ tmp2
, FIX(1.121971054)); /* c5 */
2779 tmp13
= MULTIPLY(tmp0
+ tmp3
, FIX(0.860918669)); /* c7 */
2780 tmp10
= tmp12
+ tmp13
+ tmp14
- MULTIPLY(tmp0
, FIX(0.580774953)) /* c5+c7-c1 */
2781 + MULTIPLY(tmp5
, FIX(0.184591911)); /* c11 */
2782 tmp11
= MULTIPLY(tmp2
+ tmp3
, - FIX(0.184591911)); /* -c11 */
2783 tmp12
+= tmp11
- tmp15
- MULTIPLY(tmp2
, FIX(2.339493912)) /* c1+c5-c11 */
2784 + MULTIPLY(tmp5
, FIX(0.860918669)); /* c7 */
2785 tmp13
+= tmp11
- tmp14
+ MULTIPLY(tmp3
, FIX(0.725788011)) /* c1+c11-c7 */
2786 - MULTIPLY(tmp5
, FIX(1.121971054)); /* c5 */
2787 tmp11
= tmp15
+ MULTIPLY(tmp0
- tmp3
, FIX(1.306562965)) /* c3 */
2788 - MULTIPLY(tmp2
+ tmp5
, FIX_0_541196100
); /* c9 */
2790 dataptr
[1] = (DCTELEM
) DESCALE(tmp10
, CONST_BITS
-PASS1_BITS
);
2791 dataptr
[3] = (DCTELEM
) DESCALE(tmp11
, CONST_BITS
-PASS1_BITS
);
2792 dataptr
[5] = (DCTELEM
) DESCALE(tmp12
, CONST_BITS
-PASS1_BITS
);
2793 dataptr
[7] = (DCTELEM
) DESCALE(tmp13
, CONST_BITS
-PASS1_BITS
);
2795 dataptr
+= DCTSIZE
; /* advance pointer to next row */
2798 /* Pass 2: process columns.
2799 * We remove the PASS1_BITS scaling, but leave the results scaled up
2800 * by an overall factor of 8.
2801 * We must also scale the output by (8/12)*(8/6) = 8/9, which we
2802 * partially fold into the constant multipliers and final shifting:
2803 * 6-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/12) * 16/9.
2807 for (ctr
= DCTSIZE
-1; ctr
>= 0; ctr
--) {
2810 tmp0
= dataptr
[DCTSIZE
*0] + dataptr
[DCTSIZE
*5];
2811 tmp11
= dataptr
[DCTSIZE
*1] + dataptr
[DCTSIZE
*4];
2812 tmp2
= dataptr
[DCTSIZE
*2] + dataptr
[DCTSIZE
*3];
2814 tmp10
= tmp0
+ tmp2
;
2815 tmp12
= tmp0
- tmp2
;
2817 tmp0
= dataptr
[DCTSIZE
*0] - dataptr
[DCTSIZE
*5];
2818 tmp1
= dataptr
[DCTSIZE
*1] - dataptr
[DCTSIZE
*4];
2819 tmp2
= dataptr
[DCTSIZE
*2] - dataptr
[DCTSIZE
*3];
2821 dataptr
[DCTSIZE
*0] = (DCTELEM
)
2822 DESCALE(MULTIPLY(tmp10
+ tmp11
, FIX(1.777777778)), /* 16/9 */
2823 CONST_BITS
+PASS1_BITS
+1);
2824 dataptr
[DCTSIZE
*2] = (DCTELEM
)
2825 DESCALE(MULTIPLY(tmp12
, FIX(2.177324216)), /* c2 */
2826 CONST_BITS
+PASS1_BITS
+1);
2827 dataptr
[DCTSIZE
*4] = (DCTELEM
)
2828 DESCALE(MULTIPLY(tmp10
- tmp11
- tmp11
, FIX(1.257078722)), /* c4 */
2829 CONST_BITS
+PASS1_BITS
+1);
2833 tmp10
= MULTIPLY(tmp0
+ tmp2
, FIX(0.650711829)); /* c5 */
2835 dataptr
[DCTSIZE
*1] = (DCTELEM
)
2836 DESCALE(tmp10
+ MULTIPLY(tmp0
+ tmp1
, FIX(1.777777778)), /* 16/9 */
2837 CONST_BITS
+PASS1_BITS
+1);
2838 dataptr
[DCTSIZE
*3] = (DCTELEM
)
2839 DESCALE(MULTIPLY(tmp0
- tmp1
- tmp2
, FIX(1.777777778)), /* 16/9 */
2840 CONST_BITS
+PASS1_BITS
+1);
2841 dataptr
[DCTSIZE
*5] = (DCTELEM
)
2842 DESCALE(tmp10
+ MULTIPLY(tmp2
- tmp1
, FIX(1.777777778)), /* 16/9 */
2843 CONST_BITS
+PASS1_BITS
+1);
2845 dataptr
++; /* advance pointer to next column */
2851 * Perform the forward DCT on a 10x5 sample block.
2853 * 10-point FDCT in pass 1 (rows), 5-point in pass 2 (columns).
2857 jpeg_fdct_10x5 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
2859 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
;
2860 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
;
2866 /* Zero 3 bottom rows of output coefficient block. */
2867 MEMZERO(&data
[DCTSIZE
*5], SIZEOF(DCTELEM
) * DCTSIZE
* 3);
2869 /* Pass 1: process rows. */
2870 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
2871 /* furthermore, we scale the results by 2**PASS1_BITS. */
2872 /* 10-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/20). */
2875 for (ctr
= 0; ctr
< 5; ctr
++) {
2876 elemptr
= sample_data
[ctr
] + start_col
;
2880 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[9]);
2881 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[8]);
2882 tmp12
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[7]);
2883 tmp3
= GETJSAMPLE(elemptr
[3]) + GETJSAMPLE(elemptr
[6]);
2884 tmp4
= GETJSAMPLE(elemptr
[4]) + GETJSAMPLE(elemptr
[5]);
2886 tmp10
= tmp0
+ tmp4
;
2887 tmp13
= tmp0
- tmp4
;
2888 tmp11
= tmp1
+ tmp3
;
2889 tmp14
= tmp1
- tmp3
;
2891 tmp0
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[9]);
2892 tmp1
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[8]);
2893 tmp2
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[7]);
2894 tmp3
= GETJSAMPLE(elemptr
[3]) - GETJSAMPLE(elemptr
[6]);
2895 tmp4
= GETJSAMPLE(elemptr
[4]) - GETJSAMPLE(elemptr
[5]);
2897 /* Apply unsigned->signed conversion */
2898 dataptr
[0] = (DCTELEM
)
2899 ((tmp10
+ tmp11
+ tmp12
- 10 * CENTERJSAMPLE
) << PASS1_BITS
);
2901 dataptr
[4] = (DCTELEM
)
2902 DESCALE(MULTIPLY(tmp10
- tmp12
, FIX(1.144122806)) - /* c4 */
2903 MULTIPLY(tmp11
- tmp12
, FIX(0.437016024)), /* c8 */
2904 CONST_BITS
-PASS1_BITS
);
2905 tmp10
= MULTIPLY(tmp13
+ tmp14
, FIX(0.831253876)); /* c6 */
2906 dataptr
[2] = (DCTELEM
)
2907 DESCALE(tmp10
+ MULTIPLY(tmp13
, FIX(0.513743148)), /* c2-c6 */
2908 CONST_BITS
-PASS1_BITS
);
2909 dataptr
[6] = (DCTELEM
)
2910 DESCALE(tmp10
- MULTIPLY(tmp14
, FIX(2.176250899)), /* c2+c6 */
2911 CONST_BITS
-PASS1_BITS
);
2915 tmp10
= tmp0
+ tmp4
;
2916 tmp11
= tmp1
- tmp3
;
2917 dataptr
[5] = (DCTELEM
) ((tmp10
- tmp11
- tmp2
) << PASS1_BITS
);
2918 tmp2
<<= CONST_BITS
;
2919 dataptr
[1] = (DCTELEM
)
2920 DESCALE(MULTIPLY(tmp0
, FIX(1.396802247)) + /* c1 */
2921 MULTIPLY(tmp1
, FIX(1.260073511)) + tmp2
+ /* c3 */
2922 MULTIPLY(tmp3
, FIX(0.642039522)) + /* c7 */
2923 MULTIPLY(tmp4
, FIX(0.221231742)), /* c9 */
2924 CONST_BITS
-PASS1_BITS
);
2925 tmp12
= MULTIPLY(tmp0
- tmp4
, FIX(0.951056516)) - /* (c3+c7)/2 */
2926 MULTIPLY(tmp1
+ tmp3
, FIX(0.587785252)); /* (c1-c9)/2 */
2927 tmp13
= MULTIPLY(tmp10
+ tmp11
, FIX(0.309016994)) + /* (c3-c7)/2 */
2928 (tmp11
<< (CONST_BITS
- 1)) - tmp2
;
2929 dataptr
[3] = (DCTELEM
) DESCALE(tmp12
+ tmp13
, CONST_BITS
-PASS1_BITS
);
2930 dataptr
[7] = (DCTELEM
) DESCALE(tmp12
- tmp13
, CONST_BITS
-PASS1_BITS
);
2932 dataptr
+= DCTSIZE
; /* advance pointer to next row */
2935 /* Pass 2: process columns.
2936 * We remove the PASS1_BITS scaling, but leave the results scaled up
2937 * by an overall factor of 8.
2938 * We must also scale the output by (8/10)*(8/5) = 32/25, which we
2939 * fold into the constant multipliers:
2940 * 5-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/10) * 32/25.
2944 for (ctr
= DCTSIZE
-1; ctr
>= 0; ctr
--) {
2947 tmp0
= dataptr
[DCTSIZE
*0] + dataptr
[DCTSIZE
*4];
2948 tmp1
= dataptr
[DCTSIZE
*1] + dataptr
[DCTSIZE
*3];
2949 tmp2
= dataptr
[DCTSIZE
*2];
2951 tmp10
= tmp0
+ tmp1
;
2952 tmp11
= tmp0
- tmp1
;
2954 tmp0
= dataptr
[DCTSIZE
*0] - dataptr
[DCTSIZE
*4];
2955 tmp1
= dataptr
[DCTSIZE
*1] - dataptr
[DCTSIZE
*3];
2957 dataptr
[DCTSIZE
*0] = (DCTELEM
)
2958 DESCALE(MULTIPLY(tmp10
+ tmp2
, FIX(1.28)), /* 32/25 */
2959 CONST_BITS
+PASS1_BITS
);
2960 tmp11
= MULTIPLY(tmp11
, FIX(1.011928851)); /* (c2+c4)/2 */
2962 tmp10
= MULTIPLY(tmp10
, FIX(0.452548340)); /* (c2-c4)/2 */
2963 dataptr
[DCTSIZE
*2] = (DCTELEM
) DESCALE(tmp11
+ tmp10
, CONST_BITS
+PASS1_BITS
);
2964 dataptr
[DCTSIZE
*4] = (DCTELEM
) DESCALE(tmp11
- tmp10
, CONST_BITS
+PASS1_BITS
);
2968 tmp10
= MULTIPLY(tmp0
+ tmp1
, FIX(1.064004961)); /* c3 */
2970 dataptr
[DCTSIZE
*1] = (DCTELEM
)
2971 DESCALE(tmp10
+ MULTIPLY(tmp0
, FIX(0.657591230)), /* c1-c3 */
2972 CONST_BITS
+PASS1_BITS
);
2973 dataptr
[DCTSIZE
*3] = (DCTELEM
)
2974 DESCALE(tmp10
- MULTIPLY(tmp1
, FIX(2.785601151)), /* c1+c3 */
2975 CONST_BITS
+PASS1_BITS
);
2977 dataptr
++; /* advance pointer to next column */
2983 * Perform the forward DCT on an 8x4 sample block.
2985 * 8-point FDCT in pass 1 (rows), 4-point in pass 2 (columns).
2989 jpeg_fdct_8x4 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
2991 INT32 tmp0
, tmp1
, tmp2
, tmp3
;
2992 INT32 tmp10
, tmp11
, tmp12
, tmp13
;
2999 /* Zero 4 bottom rows of output coefficient block. */
3000 MEMZERO(&data
[DCTSIZE
*4], SIZEOF(DCTELEM
) * DCTSIZE
* 4);
3002 /* Pass 1: process rows. */
3003 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
3004 /* furthermore, we scale the results by 2**PASS1_BITS. */
3005 /* We must also scale the output by 8/4 = 2, which we add here. */
3008 for (ctr
= 0; ctr
< 4; ctr
++) {
3009 elemptr
= sample_data
[ctr
] + start_col
;
3011 /* Even part per LL&M figure 1 --- note that published figure is faulty;
3012 * rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
3015 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[7]);
3016 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[6]);
3017 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[5]);
3018 tmp3
= GETJSAMPLE(elemptr
[3]) + GETJSAMPLE(elemptr
[4]);
3020 tmp10
= tmp0
+ tmp3
;
3021 tmp12
= tmp0
- tmp3
;
3022 tmp11
= tmp1
+ tmp2
;
3023 tmp13
= tmp1
- tmp2
;
3025 tmp0
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[7]);
3026 tmp1
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[6]);
3027 tmp2
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[5]);
3028 tmp3
= GETJSAMPLE(elemptr
[3]) - GETJSAMPLE(elemptr
[4]);
3030 /* Apply unsigned->signed conversion */
3031 dataptr
[0] = (DCTELEM
)
3032 ((tmp10
+ tmp11
- 8 * CENTERJSAMPLE
) << (PASS1_BITS
+1));
3033 dataptr
[4] = (DCTELEM
) ((tmp10
- tmp11
) << (PASS1_BITS
+1));
3035 z1
= MULTIPLY(tmp12
+ tmp13
, FIX_0_541196100
);
3036 /* Add fudge factor here for final descale. */
3037 z1
+= ONE
<< (CONST_BITS
-PASS1_BITS
-2);
3038 dataptr
[2] = (DCTELEM
) RIGHT_SHIFT(z1
+ MULTIPLY(tmp12
, FIX_0_765366865
),
3039 CONST_BITS
-PASS1_BITS
-1);
3040 dataptr
[6] = (DCTELEM
) RIGHT_SHIFT(z1
- MULTIPLY(tmp13
, FIX_1_847759065
),
3041 CONST_BITS
-PASS1_BITS
-1);
3043 /* Odd part per figure 8 --- note paper omits factor of sqrt(2).
3044 * 8-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
3045 * i0..i3 in the paper are tmp0..tmp3 here.
3048 tmp10
= tmp0
+ tmp3
;
3049 tmp11
= tmp1
+ tmp2
;
3050 tmp12
= tmp0
+ tmp2
;
3051 tmp13
= tmp1
+ tmp3
;
3052 z1
= MULTIPLY(tmp12
+ tmp13
, FIX_1_175875602
); /* c3 */
3053 /* Add fudge factor here for final descale. */
3054 z1
+= ONE
<< (CONST_BITS
-PASS1_BITS
-2);
3056 tmp0
= MULTIPLY(tmp0
, FIX_1_501321110
); /* c1+c3-c5-c7 */
3057 tmp1
= MULTIPLY(tmp1
, FIX_3_072711026
); /* c1+c3+c5-c7 */
3058 tmp2
= MULTIPLY(tmp2
, FIX_2_053119869
); /* c1+c3-c5+c7 */
3059 tmp3
= MULTIPLY(tmp3
, FIX_0_298631336
); /* -c1+c3+c5-c7 */
3060 tmp10
= MULTIPLY(tmp10
, - FIX_0_899976223
); /* c7-c3 */
3061 tmp11
= MULTIPLY(tmp11
, - FIX_2_562915447
); /* -c1-c3 */
3062 tmp12
= MULTIPLY(tmp12
, - FIX_0_390180644
); /* c5-c3 */
3063 tmp13
= MULTIPLY(tmp13
, - FIX_1_961570560
); /* -c3-c5 */
3068 dataptr
[1] = (DCTELEM
)
3069 RIGHT_SHIFT(tmp0
+ tmp10
+ tmp12
, CONST_BITS
-PASS1_BITS
-1);
3070 dataptr
[3] = (DCTELEM
)
3071 RIGHT_SHIFT(tmp1
+ tmp11
+ tmp13
, CONST_BITS
-PASS1_BITS
-1);
3072 dataptr
[5] = (DCTELEM
)
3073 RIGHT_SHIFT(tmp2
+ tmp11
+ tmp12
, CONST_BITS
-PASS1_BITS
-1);
3074 dataptr
[7] = (DCTELEM
)
3075 RIGHT_SHIFT(tmp3
+ tmp10
+ tmp13
, CONST_BITS
-PASS1_BITS
-1);
3077 dataptr
+= DCTSIZE
; /* advance pointer to next row */
3080 /* Pass 2: process columns.
3081 * We remove the PASS1_BITS scaling, but leave the results scaled up
3082 * by an overall factor of 8.
3083 * 4-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
3087 for (ctr
= DCTSIZE
-1; ctr
>= 0; ctr
--) {
3090 /* Add fudge factor here for final descale. */
3091 tmp0
= dataptr
[DCTSIZE
*0] + dataptr
[DCTSIZE
*3] + (ONE
<< (PASS1_BITS
-1));
3092 tmp1
= dataptr
[DCTSIZE
*1] + dataptr
[DCTSIZE
*2];
3094 tmp10
= dataptr
[DCTSIZE
*0] - dataptr
[DCTSIZE
*3];
3095 tmp11
= dataptr
[DCTSIZE
*1] - dataptr
[DCTSIZE
*2];
3097 dataptr
[DCTSIZE
*0] = (DCTELEM
) RIGHT_SHIFT(tmp0
+ tmp1
, PASS1_BITS
);
3098 dataptr
[DCTSIZE
*2] = (DCTELEM
) RIGHT_SHIFT(tmp0
- tmp1
, PASS1_BITS
);
3102 tmp0
= MULTIPLY(tmp10
+ tmp11
, FIX_0_541196100
); /* c6 */
3103 /* Add fudge factor here for final descale. */
3104 tmp0
+= ONE
<< (CONST_BITS
+PASS1_BITS
-1);
3106 dataptr
[DCTSIZE
*1] = (DCTELEM
)
3107 RIGHT_SHIFT(tmp0
+ MULTIPLY(tmp10
, FIX_0_765366865
), /* c2-c6 */
3108 CONST_BITS
+PASS1_BITS
);
3109 dataptr
[DCTSIZE
*3] = (DCTELEM
)
3110 RIGHT_SHIFT(tmp0
- MULTIPLY(tmp11
, FIX_1_847759065
), /* c2+c6 */
3111 CONST_BITS
+PASS1_BITS
);
3113 dataptr
++; /* advance pointer to next column */
3119 * Perform the forward DCT on a 6x3 sample block.
3121 * 6-point FDCT in pass 1 (rows), 3-point in pass 2 (columns).
3125 jpeg_fdct_6x3 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
3127 INT32 tmp0
, tmp1
, tmp2
;
3128 INT32 tmp10
, tmp11
, tmp12
;
3134 /* Pre-zero output coefficient block. */
3135 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
3137 /* Pass 1: process rows. */
3138 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
3139 /* furthermore, we scale the results by 2**PASS1_BITS. */
3140 /* We scale the results further by 2 as part of output adaption */
3141 /* scaling for different DCT size. */
3142 /* 6-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/12). */
3145 for (ctr
= 0; ctr
< 3; ctr
++) {
3146 elemptr
= sample_data
[ctr
] + start_col
;
3150 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[5]);
3151 tmp11
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[4]);
3152 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[3]);
3154 tmp10
= tmp0
+ tmp2
;
3155 tmp12
= tmp0
- tmp2
;
3157 tmp0
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[5]);
3158 tmp1
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[4]);
3159 tmp2
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[3]);
3161 /* Apply unsigned->signed conversion */
3162 dataptr
[0] = (DCTELEM
)
3163 ((tmp10
+ tmp11
- 6 * CENTERJSAMPLE
) << (PASS1_BITS
+1));
3164 dataptr
[2] = (DCTELEM
)
3165 DESCALE(MULTIPLY(tmp12
, FIX(1.224744871)), /* c2 */
3166 CONST_BITS
-PASS1_BITS
-1);
3167 dataptr
[4] = (DCTELEM
)
3168 DESCALE(MULTIPLY(tmp10
- tmp11
- tmp11
, FIX(0.707106781)), /* c4 */
3169 CONST_BITS
-PASS1_BITS
-1);
3173 tmp10
= DESCALE(MULTIPLY(tmp0
+ tmp2
, FIX(0.366025404)), /* c5 */
3174 CONST_BITS
-PASS1_BITS
-1);
3176 dataptr
[1] = (DCTELEM
) (tmp10
+ ((tmp0
+ tmp1
) << (PASS1_BITS
+1)));
3177 dataptr
[3] = (DCTELEM
) ((tmp0
- tmp1
- tmp2
) << (PASS1_BITS
+1));
3178 dataptr
[5] = (DCTELEM
) (tmp10
+ ((tmp2
- tmp1
) << (PASS1_BITS
+1)));
3180 dataptr
+= DCTSIZE
; /* advance pointer to next row */
3183 /* Pass 2: process columns.
3184 * We remove the PASS1_BITS scaling, but leave the results scaled up
3185 * by an overall factor of 8.
3186 * We must also scale the output by (8/6)*(8/3) = 32/9, which we partially
3187 * fold into the constant multipliers (other part was done in pass 1):
3188 * 3-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/6) * 16/9.
3192 for (ctr
= 0; ctr
< 6; ctr
++) {
3195 tmp0
= dataptr
[DCTSIZE
*0] + dataptr
[DCTSIZE
*2];
3196 tmp1
= dataptr
[DCTSIZE
*1];
3198 tmp2
= dataptr
[DCTSIZE
*0] - dataptr
[DCTSIZE
*2];
3200 dataptr
[DCTSIZE
*0] = (DCTELEM
)
3201 DESCALE(MULTIPLY(tmp0
+ tmp1
, FIX(1.777777778)), /* 16/9 */
3202 CONST_BITS
+PASS1_BITS
);
3203 dataptr
[DCTSIZE
*2] = (DCTELEM
)
3204 DESCALE(MULTIPLY(tmp0
- tmp1
- tmp1
, FIX(1.257078722)), /* c2 */
3205 CONST_BITS
+PASS1_BITS
);
3209 dataptr
[DCTSIZE
*1] = (DCTELEM
)
3210 DESCALE(MULTIPLY(tmp2
, FIX(2.177324216)), /* c1 */
3211 CONST_BITS
+PASS1_BITS
);
3213 dataptr
++; /* advance pointer to next column */
3219 * Perform the forward DCT on a 4x2 sample block.
3221 * 4-point FDCT in pass 1 (rows), 2-point in pass 2 (columns).
3225 jpeg_fdct_4x2 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
3234 /* Pre-zero output coefficient block. */
3235 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
3237 /* Pass 1: process rows. */
3238 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
3239 /* furthermore, we scale the results by 2**PASS1_BITS. */
3240 /* We must also scale the output by (8/4)*(8/2) = 2**3, which we add here. */
3241 /* 4-point FDCT kernel, */
3242 /* cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point FDCT]. */
3245 for (ctr
= 0; ctr
< 2; ctr
++) {
3246 elemptr
= sample_data
[ctr
] + start_col
;
3250 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[3]);
3251 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[2]);
3253 tmp10
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[3]);
3254 tmp11
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[2]);
3256 /* Apply unsigned->signed conversion */
3257 dataptr
[0] = (DCTELEM
)
3258 ((tmp0
+ tmp1
- 4 * CENTERJSAMPLE
) << (PASS1_BITS
+3));
3259 dataptr
[2] = (DCTELEM
) ((tmp0
- tmp1
) << (PASS1_BITS
+3));
3263 tmp0
= MULTIPLY(tmp10
+ tmp11
, FIX_0_541196100
); /* c6 */
3264 /* Add fudge factor here for final descale. */
3265 tmp0
+= ONE
<< (CONST_BITS
-PASS1_BITS
-4);
3267 dataptr
[1] = (DCTELEM
)
3268 RIGHT_SHIFT(tmp0
+ MULTIPLY(tmp10
, FIX_0_765366865
), /* c2-c6 */
3269 CONST_BITS
-PASS1_BITS
-3);
3270 dataptr
[3] = (DCTELEM
)
3271 RIGHT_SHIFT(tmp0
- MULTIPLY(tmp11
, FIX_1_847759065
), /* c2+c6 */
3272 CONST_BITS
-PASS1_BITS
-3);
3274 dataptr
+= DCTSIZE
; /* advance pointer to next row */
3277 /* Pass 2: process columns.
3278 * We remove the PASS1_BITS scaling, but leave the results scaled up
3279 * by an overall factor of 8.
3283 for (ctr
= 0; ctr
< 4; ctr
++) {
3286 /* Add fudge factor here for final descale. */
3287 tmp0
= dataptr
[DCTSIZE
*0] + (ONE
<< (PASS1_BITS
-1));
3288 tmp1
= dataptr
[DCTSIZE
*1];
3290 dataptr
[DCTSIZE
*0] = (DCTELEM
) RIGHT_SHIFT(tmp0
+ tmp1
, PASS1_BITS
);
3294 dataptr
[DCTSIZE
*1] = (DCTELEM
) RIGHT_SHIFT(tmp0
- tmp1
, PASS1_BITS
);
3296 dataptr
++; /* advance pointer to next column */
3302 * Perform the forward DCT on a 2x1 sample block.
3304 * 2-point FDCT in pass 1 (rows), 1-point in pass 2 (columns).
3308 jpeg_fdct_2x1 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
3313 /* Pre-zero output coefficient block. */
3314 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
3316 elemptr
= sample_data
[0] + start_col
;
3318 tmp0
= GETJSAMPLE(elemptr
[0]);
3319 tmp1
= GETJSAMPLE(elemptr
[1]);
3321 /* We leave the results scaled up by an overall factor of 8.
3322 * We must also scale the output by (8/2)*(8/1) = 2**5.
3326 /* Apply unsigned->signed conversion */
3327 data
[0] = (DCTELEM
) ((tmp0
+ tmp1
- 2 * CENTERJSAMPLE
) << 5);
3330 data
[1] = (DCTELEM
) ((tmp0
- tmp1
) << 5);
3335 * Perform the forward DCT on an 8x16 sample block.
3337 * 8-point FDCT in pass 1 (rows), 16-point in pass 2 (columns).
3341 jpeg_fdct_8x16 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
3343 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
, tmp5
, tmp6
, tmp7
;
3344 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
, tmp15
, tmp16
, tmp17
;
3346 DCTELEM workspace
[DCTSIZE2
];
3353 /* Pass 1: process rows. */
3354 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
3355 /* furthermore, we scale the results by 2**PASS1_BITS. */
3360 elemptr
= sample_data
[ctr
] + start_col
;
3362 /* Even part per LL&M figure 1 --- note that published figure is faulty;
3363 * rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
3366 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[7]);
3367 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[6]);
3368 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[5]);
3369 tmp3
= GETJSAMPLE(elemptr
[3]) + GETJSAMPLE(elemptr
[4]);
3371 tmp10
= tmp0
+ tmp3
;
3372 tmp12
= tmp0
- tmp3
;
3373 tmp11
= tmp1
+ tmp2
;
3374 tmp13
= tmp1
- tmp2
;
3376 tmp0
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[7]);
3377 tmp1
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[6]);
3378 tmp2
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[5]);
3379 tmp3
= GETJSAMPLE(elemptr
[3]) - GETJSAMPLE(elemptr
[4]);
3381 /* Apply unsigned->signed conversion */
3382 dataptr
[0] = (DCTELEM
) ((tmp10
+ tmp11
- 8 * CENTERJSAMPLE
) << PASS1_BITS
);
3383 dataptr
[4] = (DCTELEM
) ((tmp10
- tmp11
) << PASS1_BITS
);
3385 z1
= MULTIPLY(tmp12
+ tmp13
, FIX_0_541196100
);
3386 dataptr
[2] = (DCTELEM
) DESCALE(z1
+ MULTIPLY(tmp12
, FIX_0_765366865
),
3387 CONST_BITS
-PASS1_BITS
);
3388 dataptr
[6] = (DCTELEM
) DESCALE(z1
- MULTIPLY(tmp13
, FIX_1_847759065
),
3389 CONST_BITS
-PASS1_BITS
);
3391 /* Odd part per figure 8 --- note paper omits factor of sqrt(2).
3392 * 8-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
3393 * i0..i3 in the paper are tmp0..tmp3 here.
3396 tmp10
= tmp0
+ tmp3
;
3397 tmp11
= tmp1
+ tmp2
;
3398 tmp12
= tmp0
+ tmp2
;
3399 tmp13
= tmp1
+ tmp3
;
3400 z1
= MULTIPLY(tmp12
+ tmp13
, FIX_1_175875602
); /* c3 */
3402 tmp0
= MULTIPLY(tmp0
, FIX_1_501321110
); /* c1+c3-c5-c7 */
3403 tmp1
= MULTIPLY(tmp1
, FIX_3_072711026
); /* c1+c3+c5-c7 */
3404 tmp2
= MULTIPLY(tmp2
, FIX_2_053119869
); /* c1+c3-c5+c7 */
3405 tmp3
= MULTIPLY(tmp3
, FIX_0_298631336
); /* -c1+c3+c5-c7 */
3406 tmp10
= MULTIPLY(tmp10
, - FIX_0_899976223
); /* c7-c3 */
3407 tmp11
= MULTIPLY(tmp11
, - FIX_2_562915447
); /* -c1-c3 */
3408 tmp12
= MULTIPLY(tmp12
, - FIX_0_390180644
); /* c5-c3 */
3409 tmp13
= MULTIPLY(tmp13
, - FIX_1_961570560
); /* -c3-c5 */
3414 dataptr
[1] = (DCTELEM
) DESCALE(tmp0
+ tmp10
+ tmp12
, CONST_BITS
-PASS1_BITS
);
3415 dataptr
[3] = (DCTELEM
) DESCALE(tmp1
+ tmp11
+ tmp13
, CONST_BITS
-PASS1_BITS
);
3416 dataptr
[5] = (DCTELEM
) DESCALE(tmp2
+ tmp11
+ tmp12
, CONST_BITS
-PASS1_BITS
);
3417 dataptr
[7] = (DCTELEM
) DESCALE(tmp3
+ tmp10
+ tmp13
, CONST_BITS
-PASS1_BITS
);
3421 if (ctr
!= DCTSIZE
) {
3422 if (ctr
== DCTSIZE
* 2)
3424 dataptr
+= DCTSIZE
; /* advance pointer to next row */
3426 dataptr
= workspace
; /* switch pointer to extended workspace */
3429 /* Pass 2: process columns.
3430 * We remove the PASS1_BITS scaling, but leave the results scaled up
3431 * by an overall factor of 8.
3432 * We must also scale the output by 8/16 = 1/2.
3433 * 16-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/32).
3438 for (ctr
= DCTSIZE
-1; ctr
>= 0; ctr
--) {
3441 tmp0
= dataptr
[DCTSIZE
*0] + wsptr
[DCTSIZE
*7];
3442 tmp1
= dataptr
[DCTSIZE
*1] + wsptr
[DCTSIZE
*6];
3443 tmp2
= dataptr
[DCTSIZE
*2] + wsptr
[DCTSIZE
*5];
3444 tmp3
= dataptr
[DCTSIZE
*3] + wsptr
[DCTSIZE
*4];
3445 tmp4
= dataptr
[DCTSIZE
*4] + wsptr
[DCTSIZE
*3];
3446 tmp5
= dataptr
[DCTSIZE
*5] + wsptr
[DCTSIZE
*2];
3447 tmp6
= dataptr
[DCTSIZE
*6] + wsptr
[DCTSIZE
*1];
3448 tmp7
= dataptr
[DCTSIZE
*7] + wsptr
[DCTSIZE
*0];
3450 tmp10
= tmp0
+ tmp7
;
3451 tmp14
= tmp0
- tmp7
;
3452 tmp11
= tmp1
+ tmp6
;
3453 tmp15
= tmp1
- tmp6
;
3454 tmp12
= tmp2
+ tmp5
;
3455 tmp16
= tmp2
- tmp5
;
3456 tmp13
= tmp3
+ tmp4
;
3457 tmp17
= tmp3
- tmp4
;
3459 tmp0
= dataptr
[DCTSIZE
*0] - wsptr
[DCTSIZE
*7];
3460 tmp1
= dataptr
[DCTSIZE
*1] - wsptr
[DCTSIZE
*6];
3461 tmp2
= dataptr
[DCTSIZE
*2] - wsptr
[DCTSIZE
*5];
3462 tmp3
= dataptr
[DCTSIZE
*3] - wsptr
[DCTSIZE
*4];
3463 tmp4
= dataptr
[DCTSIZE
*4] - wsptr
[DCTSIZE
*3];
3464 tmp5
= dataptr
[DCTSIZE
*5] - wsptr
[DCTSIZE
*2];
3465 tmp6
= dataptr
[DCTSIZE
*6] - wsptr
[DCTSIZE
*1];
3466 tmp7
= dataptr
[DCTSIZE
*7] - wsptr
[DCTSIZE
*0];
3468 dataptr
[DCTSIZE
*0] = (DCTELEM
)
3469 DESCALE(tmp10
+ tmp11
+ tmp12
+ tmp13
, PASS1_BITS
+1);
3470 dataptr
[DCTSIZE
*4] = (DCTELEM
)
3471 DESCALE(MULTIPLY(tmp10
- tmp13
, FIX(1.306562965)) + /* c4[16] = c2[8] */
3472 MULTIPLY(tmp11
- tmp12
, FIX_0_541196100
), /* c12[16] = c6[8] */
3473 CONST_BITS
+PASS1_BITS
+1);
3475 tmp10
= MULTIPLY(tmp17
- tmp15
, FIX(0.275899379)) + /* c14[16] = c7[8] */
3476 MULTIPLY(tmp14
- tmp16
, FIX(1.387039845)); /* c2[16] = c1[8] */
3478 dataptr
[DCTSIZE
*2] = (DCTELEM
)
3479 DESCALE(tmp10
+ MULTIPLY(tmp15
, FIX(1.451774982)) /* c6+c14 */
3480 + MULTIPLY(tmp16
, FIX(2.172734804)), /* c2+c10 */
3481 CONST_BITS
+PASS1_BITS
+1);
3482 dataptr
[DCTSIZE
*6] = (DCTELEM
)
3483 DESCALE(tmp10
- MULTIPLY(tmp14
, FIX(0.211164243)) /* c2-c6 */
3484 - MULTIPLY(tmp17
, FIX(1.061594338)), /* c10+c14 */
3485 CONST_BITS
+PASS1_BITS
+1);
3489 tmp11
= MULTIPLY(tmp0
+ tmp1
, FIX(1.353318001)) + /* c3 */
3490 MULTIPLY(tmp6
- tmp7
, FIX(0.410524528)); /* c13 */
3491 tmp12
= MULTIPLY(tmp0
+ tmp2
, FIX(1.247225013)) + /* c5 */
3492 MULTIPLY(tmp5
+ tmp7
, FIX(0.666655658)); /* c11 */
3493 tmp13
= MULTIPLY(tmp0
+ tmp3
, FIX(1.093201867)) + /* c7 */
3494 MULTIPLY(tmp4
- tmp7
, FIX(0.897167586)); /* c9 */
3495 tmp14
= MULTIPLY(tmp1
+ tmp2
, FIX(0.138617169)) + /* c15 */
3496 MULTIPLY(tmp6
- tmp5
, FIX(1.407403738)); /* c1 */
3497 tmp15
= MULTIPLY(tmp1
+ tmp3
, - FIX(0.666655658)) + /* -c11 */
3498 MULTIPLY(tmp4
+ tmp6
, - FIX(1.247225013)); /* -c5 */
3499 tmp16
= MULTIPLY(tmp2
+ tmp3
, - FIX(1.353318001)) + /* -c3 */
3500 MULTIPLY(tmp5
- tmp4
, FIX(0.410524528)); /* c13 */
3501 tmp10
= tmp11
+ tmp12
+ tmp13
-
3502 MULTIPLY(tmp0
, FIX(2.286341144)) + /* c7+c5+c3-c1 */
3503 MULTIPLY(tmp7
, FIX(0.779653625)); /* c15+c13-c11+c9 */
3504 tmp11
+= tmp14
+ tmp15
+ MULTIPLY(tmp1
, FIX(0.071888074)) /* c9-c3-c15+c11 */
3505 - MULTIPLY(tmp6
, FIX(1.663905119)); /* c7+c13+c1-c5 */
3506 tmp12
+= tmp14
+ tmp16
- MULTIPLY(tmp2
, FIX(1.125726048)) /* c7+c5+c15-c3 */
3507 + MULTIPLY(tmp5
, FIX(1.227391138)); /* c9-c11+c1-c13 */
3508 tmp13
+= tmp15
+ tmp16
+ MULTIPLY(tmp3
, FIX(1.065388962)) /* c15+c3+c11-c7 */
3509 + MULTIPLY(tmp4
, FIX(2.167985692)); /* c1+c13+c5-c9 */
3511 dataptr
[DCTSIZE
*1] = (DCTELEM
) DESCALE(tmp10
, CONST_BITS
+PASS1_BITS
+1);
3512 dataptr
[DCTSIZE
*3] = (DCTELEM
) DESCALE(tmp11
, CONST_BITS
+PASS1_BITS
+1);
3513 dataptr
[DCTSIZE
*5] = (DCTELEM
) DESCALE(tmp12
, CONST_BITS
+PASS1_BITS
+1);
3514 dataptr
[DCTSIZE
*7] = (DCTELEM
) DESCALE(tmp13
, CONST_BITS
+PASS1_BITS
+1);
3516 dataptr
++; /* advance pointer to next column */
3517 wsptr
++; /* advance pointer to next column */
3523 * Perform the forward DCT on a 7x14 sample block.
3525 * 7-point FDCT in pass 1 (rows), 14-point in pass 2 (columns).
3529 jpeg_fdct_7x14 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
3531 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
, tmp5
, tmp6
;
3532 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
, tmp15
, tmp16
;
3534 DCTELEM workspace
[8*6];
3541 /* Pre-zero output coefficient block. */
3542 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
3544 /* Pass 1: process rows. */
3545 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
3546 /* furthermore, we scale the results by 2**PASS1_BITS. */
3547 /* 7-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/14). */
3552 elemptr
= sample_data
[ctr
] + start_col
;
3556 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[6]);
3557 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[5]);
3558 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[4]);
3559 tmp3
= GETJSAMPLE(elemptr
[3]);
3561 tmp10
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[6]);
3562 tmp11
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[5]);
3563 tmp12
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[4]);
3566 /* Apply unsigned->signed conversion */
3567 dataptr
[0] = (DCTELEM
)
3568 ((z1
+ tmp1
+ tmp3
- 7 * CENTERJSAMPLE
) << PASS1_BITS
);
3572 z1
= MULTIPLY(z1
, FIX(0.353553391)); /* (c2+c6-c4)/2 */
3573 z2
= MULTIPLY(tmp0
- tmp2
, FIX(0.920609002)); /* (c2+c4-c6)/2 */
3574 z3
= MULTIPLY(tmp1
- tmp2
, FIX(0.314692123)); /* c6 */
3575 dataptr
[2] = (DCTELEM
) DESCALE(z1
+ z2
+ z3
, CONST_BITS
-PASS1_BITS
);
3577 z2
= MULTIPLY(tmp0
- tmp1
, FIX(0.881747734)); /* c4 */
3578 dataptr
[4] = (DCTELEM
)
3579 DESCALE(z2
+ z3
- MULTIPLY(tmp1
- tmp3
, FIX(0.707106781)), /* c2+c6-c4 */
3580 CONST_BITS
-PASS1_BITS
);
3581 dataptr
[6] = (DCTELEM
) DESCALE(z1
+ z2
, CONST_BITS
-PASS1_BITS
);
3585 tmp1
= MULTIPLY(tmp10
+ tmp11
, FIX(0.935414347)); /* (c3+c1-c5)/2 */
3586 tmp2
= MULTIPLY(tmp10
- tmp11
, FIX(0.170262339)); /* (c3+c5-c1)/2 */
3589 tmp2
= MULTIPLY(tmp11
+ tmp12
, - FIX(1.378756276)); /* -c1 */
3591 tmp3
= MULTIPLY(tmp10
+ tmp12
, FIX(0.613604268)); /* c5 */
3593 tmp2
+= tmp3
+ MULTIPLY(tmp12
, FIX(1.870828693)); /* c3+c1-c5 */
3595 dataptr
[1] = (DCTELEM
) DESCALE(tmp0
, CONST_BITS
-PASS1_BITS
);
3596 dataptr
[3] = (DCTELEM
) DESCALE(tmp1
, CONST_BITS
-PASS1_BITS
);
3597 dataptr
[5] = (DCTELEM
) DESCALE(tmp2
, CONST_BITS
-PASS1_BITS
);
3601 if (ctr
!= DCTSIZE
) {
3604 dataptr
+= DCTSIZE
; /* advance pointer to next row */
3606 dataptr
= workspace
; /* switch pointer to extended workspace */
3609 /* Pass 2: process columns.
3610 * We remove the PASS1_BITS scaling, but leave the results scaled up
3611 * by an overall factor of 8.
3612 * We must also scale the output by (8/7)*(8/14) = 32/49, which we
3613 * fold into the constant multipliers:
3614 * 14-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/28) * 32/49.
3619 for (ctr
= 0; ctr
< 7; ctr
++) {
3622 tmp0
= dataptr
[DCTSIZE
*0] + wsptr
[DCTSIZE
*5];
3623 tmp1
= dataptr
[DCTSIZE
*1] + wsptr
[DCTSIZE
*4];
3624 tmp2
= dataptr
[DCTSIZE
*2] + wsptr
[DCTSIZE
*3];
3625 tmp13
= dataptr
[DCTSIZE
*3] + wsptr
[DCTSIZE
*2];
3626 tmp4
= dataptr
[DCTSIZE
*4] + wsptr
[DCTSIZE
*1];
3627 tmp5
= dataptr
[DCTSIZE
*5] + wsptr
[DCTSIZE
*0];
3628 tmp6
= dataptr
[DCTSIZE
*6] + dataptr
[DCTSIZE
*7];
3630 tmp10
= tmp0
+ tmp6
;
3631 tmp14
= tmp0
- tmp6
;
3632 tmp11
= tmp1
+ tmp5
;
3633 tmp15
= tmp1
- tmp5
;
3634 tmp12
= tmp2
+ tmp4
;
3635 tmp16
= tmp2
- tmp4
;
3637 tmp0
= dataptr
[DCTSIZE
*0] - wsptr
[DCTSIZE
*5];
3638 tmp1
= dataptr
[DCTSIZE
*1] - wsptr
[DCTSIZE
*4];
3639 tmp2
= dataptr
[DCTSIZE
*2] - wsptr
[DCTSIZE
*3];
3640 tmp3
= dataptr
[DCTSIZE
*3] - wsptr
[DCTSIZE
*2];
3641 tmp4
= dataptr
[DCTSIZE
*4] - wsptr
[DCTSIZE
*1];
3642 tmp5
= dataptr
[DCTSIZE
*5] - wsptr
[DCTSIZE
*0];
3643 tmp6
= dataptr
[DCTSIZE
*6] - dataptr
[DCTSIZE
*7];
3645 dataptr
[DCTSIZE
*0] = (DCTELEM
)
3646 DESCALE(MULTIPLY(tmp10
+ tmp11
+ tmp12
+ tmp13
,
3647 FIX(0.653061224)), /* 32/49 */
3648 CONST_BITS
+PASS1_BITS
);
3650 dataptr
[DCTSIZE
*4] = (DCTELEM
)
3651 DESCALE(MULTIPLY(tmp10
- tmp13
, FIX(0.832106052)) + /* c4 */
3652 MULTIPLY(tmp11
- tmp13
, FIX(0.205513223)) - /* c12 */
3653 MULTIPLY(tmp12
- tmp13
, FIX(0.575835255)), /* c8 */
3654 CONST_BITS
+PASS1_BITS
);
3656 tmp10
= MULTIPLY(tmp14
+ tmp15
, FIX(0.722074570)); /* c6 */
3658 dataptr
[DCTSIZE
*2] = (DCTELEM
)
3659 DESCALE(tmp10
+ MULTIPLY(tmp14
, FIX(0.178337691)) /* c2-c6 */
3660 + MULTIPLY(tmp16
, FIX(0.400721155)), /* c10 */
3661 CONST_BITS
+PASS1_BITS
);
3662 dataptr
[DCTSIZE
*6] = (DCTELEM
)
3663 DESCALE(tmp10
- MULTIPLY(tmp15
, FIX(1.122795725)) /* c6+c10 */
3664 - MULTIPLY(tmp16
, FIX(0.900412262)), /* c2 */
3665 CONST_BITS
+PASS1_BITS
);
3669 tmp10
= tmp1
+ tmp2
;
3670 tmp11
= tmp5
- tmp4
;
3671 dataptr
[DCTSIZE
*7] = (DCTELEM
)
3672 DESCALE(MULTIPLY(tmp0
- tmp10
+ tmp3
- tmp11
- tmp6
,
3673 FIX(0.653061224)), /* 32/49 */
3674 CONST_BITS
+PASS1_BITS
);
3675 tmp3
= MULTIPLY(tmp3
, FIX(0.653061224)); /* 32/49 */
3676 tmp10
= MULTIPLY(tmp10
, - FIX(0.103406812)); /* -c13 */
3677 tmp11
= MULTIPLY(tmp11
, FIX(0.917760839)); /* c1 */
3678 tmp10
+= tmp11
- tmp3
;
3679 tmp11
= MULTIPLY(tmp0
+ tmp2
, FIX(0.782007410)) + /* c5 */
3680 MULTIPLY(tmp4
+ tmp6
, FIX(0.491367823)); /* c9 */
3681 dataptr
[DCTSIZE
*5] = (DCTELEM
)
3682 DESCALE(tmp10
+ tmp11
- MULTIPLY(tmp2
, FIX(1.550341076)) /* c3+c5-c13 */
3683 + MULTIPLY(tmp4
, FIX(0.731428202)), /* c1+c11-c9 */
3684 CONST_BITS
+PASS1_BITS
);
3685 tmp12
= MULTIPLY(tmp0
+ tmp1
, FIX(0.871740478)) + /* c3 */
3686 MULTIPLY(tmp5
- tmp6
, FIX(0.305035186)); /* c11 */
3687 dataptr
[DCTSIZE
*3] = (DCTELEM
)
3688 DESCALE(tmp10
+ tmp12
- MULTIPLY(tmp1
, FIX(0.276965844)) /* c3-c9-c13 */
3689 - MULTIPLY(tmp5
, FIX(2.004803435)), /* c1+c5+c11 */
3690 CONST_BITS
+PASS1_BITS
);
3691 dataptr
[DCTSIZE
*1] = (DCTELEM
)
3692 DESCALE(tmp11
+ tmp12
+ tmp3
3693 - MULTIPLY(tmp0
, FIX(0.735987049)) /* c3+c5-c1 */
3694 - MULTIPLY(tmp6
, FIX(0.082925825)), /* c9-c11-c13 */
3695 CONST_BITS
+PASS1_BITS
);
3697 dataptr
++; /* advance pointer to next column */
3698 wsptr
++; /* advance pointer to next column */
3704 * Perform the forward DCT on a 6x12 sample block.
3706 * 6-point FDCT in pass 1 (rows), 12-point in pass 2 (columns).
3710 jpeg_fdct_6x12 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
3712 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
, tmp5
;
3713 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
, tmp15
;
3714 DCTELEM workspace
[8*4];
3721 /* Pre-zero output coefficient block. */
3722 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
3724 /* Pass 1: process rows. */
3725 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
3726 /* furthermore, we scale the results by 2**PASS1_BITS. */
3727 /* 6-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/12). */
3732 elemptr
= sample_data
[ctr
] + start_col
;
3736 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[5]);
3737 tmp11
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[4]);
3738 tmp2
= GETJSAMPLE(elemptr
[2]) + GETJSAMPLE(elemptr
[3]);
3740 tmp10
= tmp0
+ tmp2
;
3741 tmp12
= tmp0
- tmp2
;
3743 tmp0
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[5]);
3744 tmp1
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[4]);
3745 tmp2
= GETJSAMPLE(elemptr
[2]) - GETJSAMPLE(elemptr
[3]);
3747 /* Apply unsigned->signed conversion */
3748 dataptr
[0] = (DCTELEM
)
3749 ((tmp10
+ tmp11
- 6 * CENTERJSAMPLE
) << PASS1_BITS
);
3750 dataptr
[2] = (DCTELEM
)
3751 DESCALE(MULTIPLY(tmp12
, FIX(1.224744871)), /* c2 */
3752 CONST_BITS
-PASS1_BITS
);
3753 dataptr
[4] = (DCTELEM
)
3754 DESCALE(MULTIPLY(tmp10
- tmp11
- tmp11
, FIX(0.707106781)), /* c4 */
3755 CONST_BITS
-PASS1_BITS
);
3759 tmp10
= DESCALE(MULTIPLY(tmp0
+ tmp2
, FIX(0.366025404)), /* c5 */
3760 CONST_BITS
-PASS1_BITS
);
3762 dataptr
[1] = (DCTELEM
) (tmp10
+ ((tmp0
+ tmp1
) << PASS1_BITS
));
3763 dataptr
[3] = (DCTELEM
) ((tmp0
- tmp1
- tmp2
) << PASS1_BITS
);
3764 dataptr
[5] = (DCTELEM
) (tmp10
+ ((tmp2
- tmp1
) << PASS1_BITS
));
3768 if (ctr
!= DCTSIZE
) {
3771 dataptr
+= DCTSIZE
; /* advance pointer to next row */
3773 dataptr
= workspace
; /* switch pointer to extended workspace */
3776 /* Pass 2: process columns.
3777 * We remove the PASS1_BITS scaling, but leave the results scaled up
3778 * by an overall factor of 8.
3779 * We must also scale the output by (8/6)*(8/12) = 8/9, which we
3780 * fold into the constant multipliers:
3781 * 12-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/24) * 8/9.
3786 for (ctr
= 0; ctr
< 6; ctr
++) {
3789 tmp0
= dataptr
[DCTSIZE
*0] + wsptr
[DCTSIZE
*3];
3790 tmp1
= dataptr
[DCTSIZE
*1] + wsptr
[DCTSIZE
*2];
3791 tmp2
= dataptr
[DCTSIZE
*2] + wsptr
[DCTSIZE
*1];
3792 tmp3
= dataptr
[DCTSIZE
*3] + wsptr
[DCTSIZE
*0];
3793 tmp4
= dataptr
[DCTSIZE
*4] + dataptr
[DCTSIZE
*7];
3794 tmp5
= dataptr
[DCTSIZE
*5] + dataptr
[DCTSIZE
*6];
3796 tmp10
= tmp0
+ tmp5
;
3797 tmp13
= tmp0
- tmp5
;
3798 tmp11
= tmp1
+ tmp4
;
3799 tmp14
= tmp1
- tmp4
;
3800 tmp12
= tmp2
+ tmp3
;
3801 tmp15
= tmp2
- tmp3
;
3803 tmp0
= dataptr
[DCTSIZE
*0] - wsptr
[DCTSIZE
*3];
3804 tmp1
= dataptr
[DCTSIZE
*1] - wsptr
[DCTSIZE
*2];
3805 tmp2
= dataptr
[DCTSIZE
*2] - wsptr
[DCTSIZE
*1];
3806 tmp3
= dataptr
[DCTSIZE
*3] - wsptr
[DCTSIZE
*0];
3807 tmp4
= dataptr
[DCTSIZE
*4] - dataptr
[DCTSIZE
*7];
3808 tmp5
= dataptr
[DCTSIZE
*5] - dataptr
[DCTSIZE
*6];
3810 dataptr
[DCTSIZE
*0] = (DCTELEM
)
3811 DESCALE(MULTIPLY(tmp10
+ tmp11
+ tmp12
, FIX(0.888888889)), /* 8/9 */
3812 CONST_BITS
+PASS1_BITS
);
3813 dataptr
[DCTSIZE
*6] = (DCTELEM
)
3814 DESCALE(MULTIPLY(tmp13
- tmp14
- tmp15
, FIX(0.888888889)), /* 8/9 */
3815 CONST_BITS
+PASS1_BITS
);
3816 dataptr
[DCTSIZE
*4] = (DCTELEM
)
3817 DESCALE(MULTIPLY(tmp10
- tmp12
, FIX(1.088662108)), /* c4 */
3818 CONST_BITS
+PASS1_BITS
);
3819 dataptr
[DCTSIZE
*2] = (DCTELEM
)
3820 DESCALE(MULTIPLY(tmp14
- tmp15
, FIX(0.888888889)) + /* 8/9 */
3821 MULTIPLY(tmp13
+ tmp15
, FIX(1.214244803)), /* c2 */
3822 CONST_BITS
+PASS1_BITS
);
3826 tmp10
= MULTIPLY(tmp1
+ tmp4
, FIX(0.481063200)); /* c9 */
3827 tmp14
= tmp10
+ MULTIPLY(tmp1
, FIX(0.680326102)); /* c3-c9 */
3828 tmp15
= tmp10
- MULTIPLY(tmp4
, FIX(1.642452502)); /* c3+c9 */
3829 tmp12
= MULTIPLY(tmp0
+ tmp2
, FIX(0.997307603)); /* c5 */
3830 tmp13
= MULTIPLY(tmp0
+ tmp3
, FIX(0.765261039)); /* c7 */
3831 tmp10
= tmp12
+ tmp13
+ tmp14
- MULTIPLY(tmp0
, FIX(0.516244403)) /* c5+c7-c1 */
3832 + MULTIPLY(tmp5
, FIX(0.164081699)); /* c11 */
3833 tmp11
= MULTIPLY(tmp2
+ tmp3
, - FIX(0.164081699)); /* -c11 */
3834 tmp12
+= tmp11
- tmp15
- MULTIPLY(tmp2
, FIX(2.079550144)) /* c1+c5-c11 */
3835 + MULTIPLY(tmp5
, FIX(0.765261039)); /* c7 */
3836 tmp13
+= tmp11
- tmp14
+ MULTIPLY(tmp3
, FIX(0.645144899)) /* c1+c11-c7 */
3837 - MULTIPLY(tmp5
, FIX(0.997307603)); /* c5 */
3838 tmp11
= tmp15
+ MULTIPLY(tmp0
- tmp3
, FIX(1.161389302)) /* c3 */
3839 - MULTIPLY(tmp2
+ tmp5
, FIX(0.481063200)); /* c9 */
3841 dataptr
[DCTSIZE
*1] = (DCTELEM
) DESCALE(tmp10
, CONST_BITS
+PASS1_BITS
);
3842 dataptr
[DCTSIZE
*3] = (DCTELEM
) DESCALE(tmp11
, CONST_BITS
+PASS1_BITS
);
3843 dataptr
[DCTSIZE
*5] = (DCTELEM
) DESCALE(tmp12
, CONST_BITS
+PASS1_BITS
);
3844 dataptr
[DCTSIZE
*7] = (DCTELEM
) DESCALE(tmp13
, CONST_BITS
+PASS1_BITS
);
3846 dataptr
++; /* advance pointer to next column */
3847 wsptr
++; /* advance pointer to next column */
3853 * Perform the forward DCT on a 5x10 sample block.
3855 * 5-point FDCT in pass 1 (rows), 10-point in pass 2 (columns).
3859 jpeg_fdct_5x10 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
3861 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
;
3862 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
;
3863 DCTELEM workspace
[8*2];
3870 /* Pre-zero output coefficient block. */
3871 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
3873 /* Pass 1: process rows. */
3874 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
3875 /* furthermore, we scale the results by 2**PASS1_BITS. */
3876 /* 5-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/10). */
3881 elemptr
= sample_data
[ctr
] + start_col
;
3885 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[4]);
3886 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[3]);
3887 tmp2
= GETJSAMPLE(elemptr
[2]);
3889 tmp10
= tmp0
+ tmp1
;
3890 tmp11
= tmp0
- tmp1
;
3892 tmp0
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[4]);
3893 tmp1
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[3]);
3895 /* Apply unsigned->signed conversion */
3896 dataptr
[0] = (DCTELEM
)
3897 ((tmp10
+ tmp2
- 5 * CENTERJSAMPLE
) << PASS1_BITS
);
3898 tmp11
= MULTIPLY(tmp11
, FIX(0.790569415)); /* (c2+c4)/2 */
3900 tmp10
= MULTIPLY(tmp10
, FIX(0.353553391)); /* (c2-c4)/2 */
3901 dataptr
[2] = (DCTELEM
) DESCALE(tmp11
+ tmp10
, CONST_BITS
-PASS1_BITS
);
3902 dataptr
[4] = (DCTELEM
) DESCALE(tmp11
- tmp10
, CONST_BITS
-PASS1_BITS
);
3906 tmp10
= MULTIPLY(tmp0
+ tmp1
, FIX(0.831253876)); /* c3 */
3908 dataptr
[1] = (DCTELEM
)
3909 DESCALE(tmp10
+ MULTIPLY(tmp0
, FIX(0.513743148)), /* c1-c3 */
3910 CONST_BITS
-PASS1_BITS
);
3911 dataptr
[3] = (DCTELEM
)
3912 DESCALE(tmp10
- MULTIPLY(tmp1
, FIX(2.176250899)), /* c1+c3 */
3913 CONST_BITS
-PASS1_BITS
);
3917 if (ctr
!= DCTSIZE
) {
3920 dataptr
+= DCTSIZE
; /* advance pointer to next row */
3922 dataptr
= workspace
; /* switch pointer to extended workspace */
3925 /* Pass 2: process columns.
3926 * We remove the PASS1_BITS scaling, but leave the results scaled up
3927 * by an overall factor of 8.
3928 * We must also scale the output by (8/5)*(8/10) = 32/25, which we
3929 * fold into the constant multipliers:
3930 * 10-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/20) * 32/25.
3935 for (ctr
= 0; ctr
< 5; ctr
++) {
3938 tmp0
= dataptr
[DCTSIZE
*0] + wsptr
[DCTSIZE
*1];
3939 tmp1
= dataptr
[DCTSIZE
*1] + wsptr
[DCTSIZE
*0];
3940 tmp12
= dataptr
[DCTSIZE
*2] + dataptr
[DCTSIZE
*7];
3941 tmp3
= dataptr
[DCTSIZE
*3] + dataptr
[DCTSIZE
*6];
3942 tmp4
= dataptr
[DCTSIZE
*4] + dataptr
[DCTSIZE
*5];
3944 tmp10
= tmp0
+ tmp4
;
3945 tmp13
= tmp0
- tmp4
;
3946 tmp11
= tmp1
+ tmp3
;
3947 tmp14
= tmp1
- tmp3
;
3949 tmp0
= dataptr
[DCTSIZE
*0] - wsptr
[DCTSIZE
*1];
3950 tmp1
= dataptr
[DCTSIZE
*1] - wsptr
[DCTSIZE
*0];
3951 tmp2
= dataptr
[DCTSIZE
*2] - dataptr
[DCTSIZE
*7];
3952 tmp3
= dataptr
[DCTSIZE
*3] - dataptr
[DCTSIZE
*6];
3953 tmp4
= dataptr
[DCTSIZE
*4] - dataptr
[DCTSIZE
*5];
3955 dataptr
[DCTSIZE
*0] = (DCTELEM
)
3956 DESCALE(MULTIPLY(tmp10
+ tmp11
+ tmp12
, FIX(1.28)), /* 32/25 */
3957 CONST_BITS
+PASS1_BITS
);
3959 dataptr
[DCTSIZE
*4] = (DCTELEM
)
3960 DESCALE(MULTIPLY(tmp10
- tmp12
, FIX(1.464477191)) - /* c4 */
3961 MULTIPLY(tmp11
- tmp12
, FIX(0.559380511)), /* c8 */
3962 CONST_BITS
+PASS1_BITS
);
3963 tmp10
= MULTIPLY(tmp13
+ tmp14
, FIX(1.064004961)); /* c6 */
3964 dataptr
[DCTSIZE
*2] = (DCTELEM
)
3965 DESCALE(tmp10
+ MULTIPLY(tmp13
, FIX(0.657591230)), /* c2-c6 */
3966 CONST_BITS
+PASS1_BITS
);
3967 dataptr
[DCTSIZE
*6] = (DCTELEM
)
3968 DESCALE(tmp10
- MULTIPLY(tmp14
, FIX(2.785601151)), /* c2+c6 */
3969 CONST_BITS
+PASS1_BITS
);
3973 tmp10
= tmp0
+ tmp4
;
3974 tmp11
= tmp1
- tmp3
;
3975 dataptr
[DCTSIZE
*5] = (DCTELEM
)
3976 DESCALE(MULTIPLY(tmp10
- tmp11
- tmp2
, FIX(1.28)), /* 32/25 */
3977 CONST_BITS
+PASS1_BITS
);
3978 tmp2
= MULTIPLY(tmp2
, FIX(1.28)); /* 32/25 */
3979 dataptr
[DCTSIZE
*1] = (DCTELEM
)
3980 DESCALE(MULTIPLY(tmp0
, FIX(1.787906876)) + /* c1 */
3981 MULTIPLY(tmp1
, FIX(1.612894094)) + tmp2
+ /* c3 */
3982 MULTIPLY(tmp3
, FIX(0.821810588)) + /* c7 */
3983 MULTIPLY(tmp4
, FIX(0.283176630)), /* c9 */
3984 CONST_BITS
+PASS1_BITS
);
3985 tmp12
= MULTIPLY(tmp0
- tmp4
, FIX(1.217352341)) - /* (c3+c7)/2 */
3986 MULTIPLY(tmp1
+ tmp3
, FIX(0.752365123)); /* (c1-c9)/2 */
3987 tmp13
= MULTIPLY(tmp10
+ tmp11
, FIX(0.395541753)) + /* (c3-c7)/2 */
3988 MULTIPLY(tmp11
, FIX(0.64)) - tmp2
; /* 16/25 */
3989 dataptr
[DCTSIZE
*3] = (DCTELEM
) DESCALE(tmp12
+ tmp13
, CONST_BITS
+PASS1_BITS
);
3990 dataptr
[DCTSIZE
*7] = (DCTELEM
) DESCALE(tmp12
- tmp13
, CONST_BITS
+PASS1_BITS
);
3992 dataptr
++; /* advance pointer to next column */
3993 wsptr
++; /* advance pointer to next column */
3999 * Perform the forward DCT on a 4x8 sample block.
4001 * 4-point FDCT in pass 1 (rows), 8-point in pass 2 (columns).
4005 jpeg_fdct_4x8 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
4007 INT32 tmp0
, tmp1
, tmp2
, tmp3
;
4008 INT32 tmp10
, tmp11
, tmp12
, tmp13
;
4015 /* Pre-zero output coefficient block. */
4016 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
4018 /* Pass 1: process rows. */
4019 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
4020 /* furthermore, we scale the results by 2**PASS1_BITS. */
4021 /* We must also scale the output by 8/4 = 2, which we add here. */
4022 /* 4-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/16). */
4025 for (ctr
= 0; ctr
< DCTSIZE
; ctr
++) {
4026 elemptr
= sample_data
[ctr
] + start_col
;
4030 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[3]);
4031 tmp1
= GETJSAMPLE(elemptr
[1]) + GETJSAMPLE(elemptr
[2]);
4033 tmp10
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[3]);
4034 tmp11
= GETJSAMPLE(elemptr
[1]) - GETJSAMPLE(elemptr
[2]);
4036 /* Apply unsigned->signed conversion */
4037 dataptr
[0] = (DCTELEM
)
4038 ((tmp0
+ tmp1
- 4 * CENTERJSAMPLE
) << (PASS1_BITS
+1));
4039 dataptr
[2] = (DCTELEM
) ((tmp0
- tmp1
) << (PASS1_BITS
+1));
4043 tmp0
= MULTIPLY(tmp10
+ tmp11
, FIX_0_541196100
); /* c6 */
4044 /* Add fudge factor here for final descale. */
4045 tmp0
+= ONE
<< (CONST_BITS
-PASS1_BITS
-2);
4047 dataptr
[1] = (DCTELEM
)
4048 RIGHT_SHIFT(tmp0
+ MULTIPLY(tmp10
, FIX_0_765366865
), /* c2-c6 */
4049 CONST_BITS
-PASS1_BITS
-1);
4050 dataptr
[3] = (DCTELEM
)
4051 RIGHT_SHIFT(tmp0
- MULTIPLY(tmp11
, FIX_1_847759065
), /* c2+c6 */
4052 CONST_BITS
-PASS1_BITS
-1);
4054 dataptr
+= DCTSIZE
; /* advance pointer to next row */
4057 /* Pass 2: process columns.
4058 * We remove the PASS1_BITS scaling, but leave the results scaled up
4059 * by an overall factor of 8.
4063 for (ctr
= 0; ctr
< 4; ctr
++) {
4064 /* Even part per LL&M figure 1 --- note that published figure is faulty;
4065 * rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
4068 tmp0
= dataptr
[DCTSIZE
*0] + dataptr
[DCTSIZE
*7];
4069 tmp1
= dataptr
[DCTSIZE
*1] + dataptr
[DCTSIZE
*6];
4070 tmp2
= dataptr
[DCTSIZE
*2] + dataptr
[DCTSIZE
*5];
4071 tmp3
= dataptr
[DCTSIZE
*3] + dataptr
[DCTSIZE
*4];
4073 /* Add fudge factor here for final descale. */
4074 tmp10
= tmp0
+ tmp3
+ (ONE
<< (PASS1_BITS
-1));
4075 tmp12
= tmp0
- tmp3
;
4076 tmp11
= tmp1
+ tmp2
;
4077 tmp13
= tmp1
- tmp2
;
4079 tmp0
= dataptr
[DCTSIZE
*0] - dataptr
[DCTSIZE
*7];
4080 tmp1
= dataptr
[DCTSIZE
*1] - dataptr
[DCTSIZE
*6];
4081 tmp2
= dataptr
[DCTSIZE
*2] - dataptr
[DCTSIZE
*5];
4082 tmp3
= dataptr
[DCTSIZE
*3] - dataptr
[DCTSIZE
*4];
4084 dataptr
[DCTSIZE
*0] = (DCTELEM
) RIGHT_SHIFT(tmp10
+ tmp11
, PASS1_BITS
);
4085 dataptr
[DCTSIZE
*4] = (DCTELEM
) RIGHT_SHIFT(tmp10
- tmp11
, PASS1_BITS
);
4087 z1
= MULTIPLY(tmp12
+ tmp13
, FIX_0_541196100
);
4088 /* Add fudge factor here for final descale. */
4089 z1
+= ONE
<< (CONST_BITS
+PASS1_BITS
-1);
4090 dataptr
[DCTSIZE
*2] = (DCTELEM
)
4091 RIGHT_SHIFT(z1
+ MULTIPLY(tmp12
, FIX_0_765366865
), CONST_BITS
+PASS1_BITS
);
4092 dataptr
[DCTSIZE
*6] = (DCTELEM
)
4093 RIGHT_SHIFT(z1
- MULTIPLY(tmp13
, FIX_1_847759065
), CONST_BITS
+PASS1_BITS
);
4095 /* Odd part per figure 8 --- note paper omits factor of sqrt(2).
4096 * 8-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
4097 * i0..i3 in the paper are tmp0..tmp3 here.
4100 tmp10
= tmp0
+ tmp3
;
4101 tmp11
= tmp1
+ tmp2
;
4102 tmp12
= tmp0
+ tmp2
;
4103 tmp13
= tmp1
+ tmp3
;
4104 z1
= MULTIPLY(tmp12
+ tmp13
, FIX_1_175875602
); /* c3 */
4105 /* Add fudge factor here for final descale. */
4106 z1
+= ONE
<< (CONST_BITS
+PASS1_BITS
-1);
4108 tmp0
= MULTIPLY(tmp0
, FIX_1_501321110
); /* c1+c3-c5-c7 */
4109 tmp1
= MULTIPLY(tmp1
, FIX_3_072711026
); /* c1+c3+c5-c7 */
4110 tmp2
= MULTIPLY(tmp2
, FIX_2_053119869
); /* c1+c3-c5+c7 */
4111 tmp3
= MULTIPLY(tmp3
, FIX_0_298631336
); /* -c1+c3+c5-c7 */
4112 tmp10
= MULTIPLY(tmp10
, - FIX_0_899976223
); /* c7-c3 */
4113 tmp11
= MULTIPLY(tmp11
, - FIX_2_562915447
); /* -c1-c3 */
4114 tmp12
= MULTIPLY(tmp12
, - FIX_0_390180644
); /* c5-c3 */
4115 tmp13
= MULTIPLY(tmp13
, - FIX_1_961570560
); /* -c3-c5 */
4120 dataptr
[DCTSIZE
*1] = (DCTELEM
)
4121 RIGHT_SHIFT(tmp0
+ tmp10
+ tmp12
, CONST_BITS
+PASS1_BITS
);
4122 dataptr
[DCTSIZE
*3] = (DCTELEM
)
4123 RIGHT_SHIFT(tmp1
+ tmp11
+ tmp13
, CONST_BITS
+PASS1_BITS
);
4124 dataptr
[DCTSIZE
*5] = (DCTELEM
)
4125 RIGHT_SHIFT(tmp2
+ tmp11
+ tmp12
, CONST_BITS
+PASS1_BITS
);
4126 dataptr
[DCTSIZE
*7] = (DCTELEM
)
4127 RIGHT_SHIFT(tmp3
+ tmp10
+ tmp13
, CONST_BITS
+PASS1_BITS
);
4129 dataptr
++; /* advance pointer to next column */
4135 * Perform the forward DCT on a 3x6 sample block.
4137 * 3-point FDCT in pass 1 (rows), 6-point in pass 2 (columns).
4141 jpeg_fdct_3x6 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
4143 INT32 tmp0
, tmp1
, tmp2
;
4144 INT32 tmp10
, tmp11
, tmp12
;
4150 /* Pre-zero output coefficient block. */
4151 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
4153 /* Pass 1: process rows. */
4154 /* Note results are scaled up by sqrt(8) compared to a true DCT; */
4155 /* furthermore, we scale the results by 2**PASS1_BITS. */
4156 /* We scale the results further by 2 as part of output adaption */
4157 /* scaling for different DCT size. */
4158 /* 3-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/6). */
4161 for (ctr
= 0; ctr
< 6; ctr
++) {
4162 elemptr
= sample_data
[ctr
] + start_col
;
4166 tmp0
= GETJSAMPLE(elemptr
[0]) + GETJSAMPLE(elemptr
[2]);
4167 tmp1
= GETJSAMPLE(elemptr
[1]);
4169 tmp2
= GETJSAMPLE(elemptr
[0]) - GETJSAMPLE(elemptr
[2]);
4171 /* Apply unsigned->signed conversion */
4172 dataptr
[0] = (DCTELEM
)
4173 ((tmp0
+ tmp1
- 3 * CENTERJSAMPLE
) << (PASS1_BITS
+1));
4174 dataptr
[2] = (DCTELEM
)
4175 DESCALE(MULTIPLY(tmp0
- tmp1
- tmp1
, FIX(0.707106781)), /* c2 */
4176 CONST_BITS
-PASS1_BITS
-1);
4180 dataptr
[1] = (DCTELEM
)
4181 DESCALE(MULTIPLY(tmp2
, FIX(1.224744871)), /* c1 */
4182 CONST_BITS
-PASS1_BITS
-1);
4184 dataptr
+= DCTSIZE
; /* advance pointer to next row */
4187 /* Pass 2: process columns.
4188 * We remove the PASS1_BITS scaling, but leave the results scaled up
4189 * by an overall factor of 8.
4190 * We must also scale the output by (8/6)*(8/3) = 32/9, which we partially
4191 * fold into the constant multipliers (other part was done in pass 1):
4192 * 6-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/12) * 16/9.
4196 for (ctr
= 0; ctr
< 3; ctr
++) {
4199 tmp0
= dataptr
[DCTSIZE
*0] + dataptr
[DCTSIZE
*5];
4200 tmp11
= dataptr
[DCTSIZE
*1] + dataptr
[DCTSIZE
*4];
4201 tmp2
= dataptr
[DCTSIZE
*2] + dataptr
[DCTSIZE
*3];
4203 tmp10
= tmp0
+ tmp2
;
4204 tmp12
= tmp0
- tmp2
;
4206 tmp0
= dataptr
[DCTSIZE
*0] - dataptr
[DCTSIZE
*5];
4207 tmp1
= dataptr
[DCTSIZE
*1] - dataptr
[DCTSIZE
*4];
4208 tmp2
= dataptr
[DCTSIZE
*2] - dataptr
[DCTSIZE
*3];
4210 dataptr
[DCTSIZE
*0] = (DCTELEM
)
4211 DESCALE(MULTIPLY(tmp10
+ tmp11
, FIX(1.777777778)), /* 16/9 */
4212 CONST_BITS
+PASS1_BITS
);
4213 dataptr
[DCTSIZE
*2] = (DCTELEM
)
4214 DESCALE(MULTIPLY(tmp12
, FIX(2.177324216)), /* c2 */
4215 CONST_BITS
+PASS1_BITS
);
4216 dataptr
[DCTSIZE
*4] = (DCTELEM
)
4217 DESCALE(MULTIPLY(tmp10
- tmp11
- tmp11
, FIX(1.257078722)), /* c4 */
4218 CONST_BITS
+PASS1_BITS
);
4222 tmp10
= MULTIPLY(tmp0
+ tmp2
, FIX(0.650711829)); /* c5 */
4224 dataptr
[DCTSIZE
*1] = (DCTELEM
)
4225 DESCALE(tmp10
+ MULTIPLY(tmp0
+ tmp1
, FIX(1.777777778)), /* 16/9 */
4226 CONST_BITS
+PASS1_BITS
);
4227 dataptr
[DCTSIZE
*3] = (DCTELEM
)
4228 DESCALE(MULTIPLY(tmp0
- tmp1
- tmp2
, FIX(1.777777778)), /* 16/9 */
4229 CONST_BITS
+PASS1_BITS
);
4230 dataptr
[DCTSIZE
*5] = (DCTELEM
)
4231 DESCALE(tmp10
+ MULTIPLY(tmp2
- tmp1
, FIX(1.777777778)), /* 16/9 */
4232 CONST_BITS
+PASS1_BITS
);
4234 dataptr
++; /* advance pointer to next column */
4240 * Perform the forward DCT on a 2x4 sample block.
4242 * 2-point FDCT in pass 1 (rows), 4-point in pass 2 (columns).
4246 jpeg_fdct_2x4 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
4255 /* Pre-zero output coefficient block. */
4256 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
4258 /* Pass 1: process rows. */
4259 /* Note results are scaled up by sqrt(8) compared to a true DCT. */
4260 /* We must also scale the output by (8/2)*(8/4) = 2**3, which we add here. */
4263 for (ctr
= 0; ctr
< 4; ctr
++) {
4264 elemptr
= sample_data
[ctr
] + start_col
;
4268 tmp0
= GETJSAMPLE(elemptr
[0]);
4269 tmp1
= GETJSAMPLE(elemptr
[1]);
4271 /* Apply unsigned->signed conversion */
4272 dataptr
[0] = (DCTELEM
) ((tmp0
+ tmp1
- 2 * CENTERJSAMPLE
) << 3);
4276 dataptr
[1] = (DCTELEM
) ((tmp0
- tmp1
) << 3);
4278 dataptr
+= DCTSIZE
; /* advance pointer to next row */
4281 /* Pass 2: process columns.
4282 * We leave the results scaled up by an overall factor of 8.
4283 * 4-point FDCT kernel,
4284 * cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point FDCT].
4288 for (ctr
= 0; ctr
< 2; ctr
++) {
4291 tmp0
= dataptr
[DCTSIZE
*0] + dataptr
[DCTSIZE
*3];
4292 tmp1
= dataptr
[DCTSIZE
*1] + dataptr
[DCTSIZE
*2];
4294 tmp10
= dataptr
[DCTSIZE
*0] - dataptr
[DCTSIZE
*3];
4295 tmp11
= dataptr
[DCTSIZE
*1] - dataptr
[DCTSIZE
*2];
4297 dataptr
[DCTSIZE
*0] = (DCTELEM
) (tmp0
+ tmp1
);
4298 dataptr
[DCTSIZE
*2] = (DCTELEM
) (tmp0
- tmp1
);
4302 tmp0
= MULTIPLY(tmp10
+ tmp11
, FIX_0_541196100
); /* c6 */
4303 /* Add fudge factor here for final descale. */
4304 tmp0
+= ONE
<< (CONST_BITS
-1);
4306 dataptr
[DCTSIZE
*1] = (DCTELEM
)
4307 RIGHT_SHIFT(tmp0
+ MULTIPLY(tmp10
, FIX_0_765366865
), /* c2-c6 */
4309 dataptr
[DCTSIZE
*3] = (DCTELEM
)
4310 RIGHT_SHIFT(tmp0
- MULTIPLY(tmp11
, FIX_1_847759065
), /* c2+c6 */
4313 dataptr
++; /* advance pointer to next column */
4319 * Perform the forward DCT on a 1x2 sample block.
4321 * 1-point FDCT in pass 1 (rows), 2-point in pass 2 (columns).
4325 jpeg_fdct_1x2 (DCTELEM
* data
, JSAMPARRAY sample_data
, JDIMENSION start_col
)
4329 /* Pre-zero output coefficient block. */
4330 MEMZERO(data
, SIZEOF(DCTELEM
) * DCTSIZE2
);
4332 tmp0
= GETJSAMPLE(sample_data
[0][start_col
]);
4333 tmp1
= GETJSAMPLE(sample_data
[1][start_col
]);
4335 /* We leave the results scaled up by an overall factor of 8.
4336 * We must also scale the output by (8/1)*(8/2) = 2**5.
4340 /* Apply unsigned->signed conversion */
4341 data
[DCTSIZE
*0] = (DCTELEM
) ((tmp0
+ tmp1
- 2 * CENTERJSAMPLE
) << 5);
4344 data
[DCTSIZE
*1] = (DCTELEM
) ((tmp0
- tmp1
) << 5);
4347 #endif /* DCT_SCALING_SUPPORTED */
4348 #endif /* DCT_ISLOW_SUPPORTED */