4 * Copyright (C) 1991-1998, Thomas G. Lane.
5 * Modification developed 2002-2013 by Guido Vollbeding.
6 * This file is part of the Independent JPEG Group's software.
7 * For conditions of distribution and use, see the accompanying README file.
9 * This file contains a slow-but-accurate integer implementation of the
10 * inverse DCT (Discrete Cosine Transform). In the IJG code, this routine
11 * must also perform dequantization of the input coefficients.
13 * A 2-D IDCT can be done by 1-D IDCT on each column followed by 1-D IDCT
14 * on each row (or vice versa, but it's more convenient to emit a row at
15 * a time). Direct algorithms are also available, but they are much more
16 * complex and seem not to be any faster when reduced to code.
18 * This implementation is based on an algorithm described in
19 * C. Loeffler, A. Ligtenberg and G. Moschytz, "Practical Fast 1-D DCT
20 * Algorithms with 11 Multiplications", Proc. Int'l. Conf. on Acoustics,
21 * Speech, and Signal Processing 1989 (ICASSP '89), pp. 988-991.
22 * The primary algorithm described there uses 11 multiplies and 29 adds.
23 * We use their alternate method with 12 multiplies and 32 adds.
24 * The advantage of this method is that no data path contains more than one
25 * multiplication; this allows a very simple and accurate implementation in
26 * scaled fixed-point arithmetic, with a minimal number of shifts.
28 * We also provide IDCT routines with various output sample block sizes for
29 * direct resolution reduction or enlargement and for direct resolving the
30 * common 2x1 and 1x2 subsampling cases without additional resampling: NxN
31 * (N=1...16), 2NxN, and Nx2N (N=1...8) pixels for one 8x8 input DCT block.
33 * For N<8 we simply take the corresponding low-frequency coefficients of
34 * the 8x8 input DCT block and apply an NxN point IDCT on the sub-block
35 * to yield the downscaled outputs.
36 * This can be seen as direct low-pass downsampling from the DCT domain
37 * point of view rather than the usual spatial domain point of view,
38 * yielding significant computational savings and results at least
39 * as good as common bilinear (averaging) spatial downsampling.
41 * For N>8 we apply a partial NxN IDCT on the 8 input coefficients as
42 * lower frequencies and higher frequencies assumed to be zero.
43 * It turns out that the computational effort is similar to the 8x8 IDCT
44 * regarding the output size.
45 * Furthermore, the scaling and descaling is the same for all IDCT sizes.
47 * CAUTION: We rely on the FIX() macro except for the N=1,2,4,8 cases
48 * since there would be too many additional constants to pre-calculate.
51 #define JPEG_INTERNALS
54 #include "jdct.h" /* Private declarations for DCT subsystem */
56 #ifdef DCT_ISLOW_SUPPORTED
60 * This module is specialized to the case DCTSIZE = 8.
64 Sorry
, this code only copes with
8x8 DCT blocks
. /* deliberate syntax err */
69 * The poop on this scaling stuff is as follows:
71 * Each 1-D IDCT step produces outputs which are a factor of sqrt(N)
72 * larger than the true IDCT outputs. The final outputs are therefore
73 * a factor of N larger than desired; since N=8 this can be cured by
74 * a simple right shift at the end of the algorithm. The advantage of
75 * this arrangement is that we save two multiplications per 1-D IDCT,
76 * because the y0 and y4 inputs need not be divided by sqrt(N).
78 * We have to do addition and subtraction of the integer inputs, which
79 * is no problem, and multiplication by fractional constants, which is
80 * a problem to do in integer arithmetic. We multiply all the constants
81 * by CONST_SCALE and convert them to integer constants (thus retaining
82 * CONST_BITS bits of precision in the constants). After doing a
83 * multiplication we have to divide the product by CONST_SCALE, with proper
84 * rounding, to produce the correct output. This division can be done
85 * cheaply as a right shift of CONST_BITS bits. We postpone shifting
86 * as long as possible so that partial sums can be added together with
87 * full fractional precision.
89 * The outputs of the first pass are scaled up by PASS1_BITS bits so that
90 * they are represented to better-than-integral precision. These outputs
91 * require BITS_IN_JSAMPLE + PASS1_BITS + 3 bits; this fits in a 16-bit word
92 * with the recommended scaling. (To scale up 12-bit sample data further, an
93 * intermediate INT32 array would be needed.)
95 * To avoid overflow of the 32-bit intermediate results in pass 2, we must
96 * have BITS_IN_JSAMPLE + CONST_BITS + PASS1_BITS <= 26. Error analysis
97 * shows that the values given below are the most effective.
100 #if BITS_IN_JSAMPLE == 8
101 #define CONST_BITS 13
104 #define CONST_BITS 13
105 #define PASS1_BITS 1 /* lose a little precision to avoid overflow */
108 /* Some C compilers fail to reduce "FIX(constant)" at compile time, thus
109 * causing a lot of useless floating-point operations at run time.
110 * To get around this we use the following pre-calculated constants.
111 * If you change CONST_BITS you may want to add appropriate values.
112 * (With a reasonable C compiler, you can just rely on the FIX() macro...)
116 #define FIX_0_298631336 ((INT32) 2446) /* FIX(0.298631336) */
117 #define FIX_0_390180644 ((INT32) 3196) /* FIX(0.390180644) */
118 #define FIX_0_541196100 ((INT32) 4433) /* FIX(0.541196100) */
119 #define FIX_0_765366865 ((INT32) 6270) /* FIX(0.765366865) */
120 #define FIX_0_899976223 ((INT32) 7373) /* FIX(0.899976223) */
121 #define FIX_1_175875602 ((INT32) 9633) /* FIX(1.175875602) */
122 #define FIX_1_501321110 ((INT32) 12299) /* FIX(1.501321110) */
123 #define FIX_1_847759065 ((INT32) 15137) /* FIX(1.847759065) */
124 #define FIX_1_961570560 ((INT32) 16069) /* FIX(1.961570560) */
125 #define FIX_2_053119869 ((INT32) 16819) /* FIX(2.053119869) */
126 #define FIX_2_562915447 ((INT32) 20995) /* FIX(2.562915447) */
127 #define FIX_3_072711026 ((INT32) 25172) /* FIX(3.072711026) */
129 #define FIX_0_298631336 FIX(0.298631336)
130 #define FIX_0_390180644 FIX(0.390180644)
131 #define FIX_0_541196100 FIX(0.541196100)
132 #define FIX_0_765366865 FIX(0.765366865)
133 #define FIX_0_899976223 FIX(0.899976223)
134 #define FIX_1_175875602 FIX(1.175875602)
135 #define FIX_1_501321110 FIX(1.501321110)
136 #define FIX_1_847759065 FIX(1.847759065)
137 #define FIX_1_961570560 FIX(1.961570560)
138 #define FIX_2_053119869 FIX(2.053119869)
139 #define FIX_2_562915447 FIX(2.562915447)
140 #define FIX_3_072711026 FIX(3.072711026)
144 /* Multiply an INT32 variable by an INT32 constant to yield an INT32 result.
145 * For 8-bit samples with the recommended scaling, all the variable
146 * and constant values involved are no more than 16 bits wide, so a
147 * 16x16->32 bit multiply can be used instead of a full 32x32 multiply.
148 * For 12-bit samples, a full 32-bit multiplication will be needed.
151 #if BITS_IN_JSAMPLE == 8
152 #define MULTIPLY(var,const) MULTIPLY16C16(var,const)
154 #define MULTIPLY(var,const) ((var) * (const))
158 /* Dequantize a coefficient by multiplying it by the multiplier-table
159 * entry; produce an int result. In this module, both inputs and result
160 * are 16 bits or less, so either int or short multiply will work.
163 #define DEQUANTIZE(coef,quantval) (((ISLOW_MULT_TYPE) (coef)) * (quantval))
167 * Perform dequantization and inverse DCT on one block of coefficients.
169 * cK represents sqrt(2) * cos(K*pi/16).
173 jpeg_idct_islow (j_decompress_ptr cinfo
, jpeg_component_info
* compptr
,
175 JSAMPARRAY output_buf
, JDIMENSION output_col
)
177 INT32 tmp0
, tmp1
, tmp2
, tmp3
;
178 INT32 tmp10
, tmp11
, tmp12
, tmp13
;
181 ISLOW_MULT_TYPE
* quantptr
;
184 JSAMPLE
*range_limit
= IDCT_range_limit(cinfo
);
186 int workspace
[DCTSIZE2
]; /* buffers data between passes */
189 /* Pass 1: process columns from input, store into work array.
190 * Note results are scaled up by sqrt(8) compared to a true IDCT;
191 * furthermore, we scale the results by 2**PASS1_BITS.
195 quantptr
= (ISLOW_MULT_TYPE
*) compptr
->dct_table
;
197 for (ctr
= DCTSIZE
; ctr
> 0; ctr
--) {
198 /* Due to quantization, we will usually find that many of the input
199 * coefficients are zero, especially the AC terms. We can exploit this
200 * by short-circuiting the IDCT calculation for any column in which all
201 * the AC terms are zero. In that case each output is equal to the
202 * DC coefficient (with scale factor as needed).
203 * With typical images and quantization tables, half or more of the
204 * column DCT calculations can be simplified this way.
207 if (inptr
[DCTSIZE
*1] == 0 && inptr
[DCTSIZE
*2] == 0 &&
208 inptr
[DCTSIZE
*3] == 0 && inptr
[DCTSIZE
*4] == 0 &&
209 inptr
[DCTSIZE
*5] == 0 && inptr
[DCTSIZE
*6] == 0 &&
210 inptr
[DCTSIZE
*7] == 0) {
211 /* AC terms all zero */
212 int dcval
= DEQUANTIZE(inptr
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]) << PASS1_BITS
;
214 wsptr
[DCTSIZE
*0] = dcval
;
215 wsptr
[DCTSIZE
*1] = dcval
;
216 wsptr
[DCTSIZE
*2] = dcval
;
217 wsptr
[DCTSIZE
*3] = dcval
;
218 wsptr
[DCTSIZE
*4] = dcval
;
219 wsptr
[DCTSIZE
*5] = dcval
;
220 wsptr
[DCTSIZE
*6] = dcval
;
221 wsptr
[DCTSIZE
*7] = dcval
;
223 inptr
++; /* advance pointers to next column */
229 /* Even part: reverse the even part of the forward DCT.
230 * The rotator is c(-6).
233 z2
= DEQUANTIZE(inptr
[DCTSIZE
*2], quantptr
[DCTSIZE
*2]);
234 z3
= DEQUANTIZE(inptr
[DCTSIZE
*6], quantptr
[DCTSIZE
*6]);
236 z1
= MULTIPLY(z2
+ z3
, FIX_0_541196100
); /* c6 */
237 tmp2
= z1
+ MULTIPLY(z2
, FIX_0_765366865
); /* c2-c6 */
238 tmp3
= z1
- MULTIPLY(z3
, FIX_1_847759065
); /* c2+c6 */
240 z2
= DEQUANTIZE(inptr
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]);
241 z3
= DEQUANTIZE(inptr
[DCTSIZE
*4], quantptr
[DCTSIZE
*4]);
244 /* Add fudge factor here for final descale. */
245 z2
+= ONE
<< (CONST_BITS
-PASS1_BITS
-1);
255 /* Odd part per figure 8; the matrix is unitary and hence its
256 * transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively.
259 tmp0
= DEQUANTIZE(inptr
[DCTSIZE
*7], quantptr
[DCTSIZE
*7]);
260 tmp1
= DEQUANTIZE(inptr
[DCTSIZE
*5], quantptr
[DCTSIZE
*5]);
261 tmp2
= DEQUANTIZE(inptr
[DCTSIZE
*3], quantptr
[DCTSIZE
*3]);
262 tmp3
= DEQUANTIZE(inptr
[DCTSIZE
*1], quantptr
[DCTSIZE
*1]);
267 z1
= MULTIPLY(z2
+ z3
, FIX_1_175875602
); /* c3 */
268 z2
= MULTIPLY(z2
, - FIX_1_961570560
); /* -c3-c5 */
269 z3
= MULTIPLY(z3
, - FIX_0_390180644
); /* -c3+c5 */
273 z1
= MULTIPLY(tmp0
+ tmp3
, - FIX_0_899976223
); /* -c3+c7 */
274 tmp0
= MULTIPLY(tmp0
, FIX_0_298631336
); /* -c1+c3+c5-c7 */
275 tmp3
= MULTIPLY(tmp3
, FIX_1_501321110
); /* c1+c3-c5-c7 */
279 z1
= MULTIPLY(tmp1
+ tmp2
, - FIX_2_562915447
); /* -c1-c3 */
280 tmp1
= MULTIPLY(tmp1
, FIX_2_053119869
); /* c1+c3-c5+c7 */
281 tmp2
= MULTIPLY(tmp2
, FIX_3_072711026
); /* c1+c3+c5-c7 */
285 /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
287 wsptr
[DCTSIZE
*0] = (int) RIGHT_SHIFT(tmp10
+ tmp3
, CONST_BITS
-PASS1_BITS
);
288 wsptr
[DCTSIZE
*7] = (int) RIGHT_SHIFT(tmp10
- tmp3
, CONST_BITS
-PASS1_BITS
);
289 wsptr
[DCTSIZE
*1] = (int) RIGHT_SHIFT(tmp11
+ tmp2
, CONST_BITS
-PASS1_BITS
);
290 wsptr
[DCTSIZE
*6] = (int) RIGHT_SHIFT(tmp11
- tmp2
, CONST_BITS
-PASS1_BITS
);
291 wsptr
[DCTSIZE
*2] = (int) RIGHT_SHIFT(tmp12
+ tmp1
, CONST_BITS
-PASS1_BITS
);
292 wsptr
[DCTSIZE
*5] = (int) RIGHT_SHIFT(tmp12
- tmp1
, CONST_BITS
-PASS1_BITS
);
293 wsptr
[DCTSIZE
*3] = (int) RIGHT_SHIFT(tmp13
+ tmp0
, CONST_BITS
-PASS1_BITS
);
294 wsptr
[DCTSIZE
*4] = (int) RIGHT_SHIFT(tmp13
- tmp0
, CONST_BITS
-PASS1_BITS
);
296 inptr
++; /* advance pointers to next column */
301 /* Pass 2: process rows from work array, store into output array.
302 * Note that we must descale the results by a factor of 8 == 2**3,
303 * and also undo the PASS1_BITS scaling.
307 for (ctr
= 0; ctr
< DCTSIZE
; ctr
++) {
308 outptr
= output_buf
[ctr
] + output_col
;
309 /* Rows of zeroes can be exploited in the same way as we did with columns.
310 * However, the column calculation has created many nonzero AC terms, so
311 * the simplification applies less often (typically 5% to 10% of the time).
312 * On machines with very fast multiplication, it's possible that the
313 * test takes more time than it's worth. In that case this section
314 * may be commented out.
317 #ifndef NO_ZERO_ROW_TEST
318 if (wsptr
[1] == 0 && wsptr
[2] == 0 && wsptr
[3] == 0 && wsptr
[4] == 0 &&
319 wsptr
[5] == 0 && wsptr
[6] == 0 && wsptr
[7] == 0) {
320 /* AC terms all zero */
321 JSAMPLE dcval
= range_limit
[(int) DESCALE((INT32
) wsptr
[0], PASS1_BITS
+3)
333 wsptr
+= DCTSIZE
; /* advance pointer to next row */
338 /* Even part: reverse the even part of the forward DCT.
339 * The rotator is c(-6).
342 z2
= (INT32
) wsptr
[2];
343 z3
= (INT32
) wsptr
[6];
345 z1
= MULTIPLY(z2
+ z3
, FIX_0_541196100
); /* c6 */
346 tmp2
= z1
+ MULTIPLY(z2
, FIX_0_765366865
); /* c2-c6 */
347 tmp3
= z1
- MULTIPLY(z3
, FIX_1_847759065
); /* c2+c6 */
349 /* Add fudge factor here for final descale. */
350 z2
= (INT32
) wsptr
[0] + (ONE
<< (PASS1_BITS
+2));
351 z3
= (INT32
) wsptr
[4];
353 tmp0
= (z2
+ z3
) << CONST_BITS
;
354 tmp1
= (z2
- z3
) << CONST_BITS
;
361 /* Odd part per figure 8; the matrix is unitary and hence its
362 * transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively.
365 tmp0
= (INT32
) wsptr
[7];
366 tmp1
= (INT32
) wsptr
[5];
367 tmp2
= (INT32
) wsptr
[3];
368 tmp3
= (INT32
) wsptr
[1];
373 z1
= MULTIPLY(z2
+ z3
, FIX_1_175875602
); /* c3 */
374 z2
= MULTIPLY(z2
, - FIX_1_961570560
); /* -c3-c5 */
375 z3
= MULTIPLY(z3
, - FIX_0_390180644
); /* -c3+c5 */
379 z1
= MULTIPLY(tmp0
+ tmp3
, - FIX_0_899976223
); /* -c3+c7 */
380 tmp0
= MULTIPLY(tmp0
, FIX_0_298631336
); /* -c1+c3+c5-c7 */
381 tmp3
= MULTIPLY(tmp3
, FIX_1_501321110
); /* c1+c3-c5-c7 */
385 z1
= MULTIPLY(tmp1
+ tmp2
, - FIX_2_562915447
); /* -c1-c3 */
386 tmp1
= MULTIPLY(tmp1
, FIX_2_053119869
); /* c1+c3-c5+c7 */
387 tmp2
= MULTIPLY(tmp2
, FIX_3_072711026
); /* c1+c3+c5-c7 */
391 /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
393 outptr
[0] = range_limit
[(int) RIGHT_SHIFT(tmp10
+ tmp3
,
394 CONST_BITS
+PASS1_BITS
+3)
396 outptr
[7] = range_limit
[(int) RIGHT_SHIFT(tmp10
- tmp3
,
397 CONST_BITS
+PASS1_BITS
+3)
399 outptr
[1] = range_limit
[(int) RIGHT_SHIFT(tmp11
+ tmp2
,
400 CONST_BITS
+PASS1_BITS
+3)
402 outptr
[6] = range_limit
[(int) RIGHT_SHIFT(tmp11
- tmp2
,
403 CONST_BITS
+PASS1_BITS
+3)
405 outptr
[2] = range_limit
[(int) RIGHT_SHIFT(tmp12
+ tmp1
,
406 CONST_BITS
+PASS1_BITS
+3)
408 outptr
[5] = range_limit
[(int) RIGHT_SHIFT(tmp12
- tmp1
,
409 CONST_BITS
+PASS1_BITS
+3)
411 outptr
[3] = range_limit
[(int) RIGHT_SHIFT(tmp13
+ tmp0
,
412 CONST_BITS
+PASS1_BITS
+3)
414 outptr
[4] = range_limit
[(int) RIGHT_SHIFT(tmp13
- tmp0
,
415 CONST_BITS
+PASS1_BITS
+3)
418 wsptr
+= DCTSIZE
; /* advance pointer to next row */
422 #ifdef IDCT_SCALING_SUPPORTED
426 * Perform dequantization and inverse DCT on one block of coefficients,
427 * producing a 7x7 output block.
429 * Optimized algorithm with 12 multiplications in the 1-D kernel.
430 * cK represents sqrt(2) * cos(K*pi/14).
434 jpeg_idct_7x7 (j_decompress_ptr cinfo
, jpeg_component_info
* compptr
,
436 JSAMPARRAY output_buf
, JDIMENSION output_col
)
438 INT32 tmp0
, tmp1
, tmp2
, tmp10
, tmp11
, tmp12
, tmp13
;
441 ISLOW_MULT_TYPE
* quantptr
;
444 JSAMPLE
*range_limit
= IDCT_range_limit(cinfo
);
446 int workspace
[7*7]; /* buffers data between passes */
449 /* Pass 1: process columns from input, store into work array. */
452 quantptr
= (ISLOW_MULT_TYPE
*) compptr
->dct_table
;
454 for (ctr
= 0; ctr
< 7; ctr
++, inptr
++, quantptr
++, wsptr
++) {
457 tmp13
= DEQUANTIZE(inptr
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]);
458 tmp13
<<= CONST_BITS
;
459 /* Add fudge factor here for final descale. */
460 tmp13
+= ONE
<< (CONST_BITS
-PASS1_BITS
-1);
462 z1
= DEQUANTIZE(inptr
[DCTSIZE
*2], quantptr
[DCTSIZE
*2]);
463 z2
= DEQUANTIZE(inptr
[DCTSIZE
*4], quantptr
[DCTSIZE
*4]);
464 z3
= DEQUANTIZE(inptr
[DCTSIZE
*6], quantptr
[DCTSIZE
*6]);
466 tmp10
= MULTIPLY(z2
- z3
, FIX(0.881747734)); /* c4 */
467 tmp12
= MULTIPLY(z1
- z2
, FIX(0.314692123)); /* c6 */
468 tmp11
= tmp10
+ tmp12
+ tmp13
- MULTIPLY(z2
, FIX(1.841218003)); /* c2+c4-c6 */
471 tmp0
= MULTIPLY(tmp0
, FIX(1.274162392)) + tmp13
; /* c2 */
472 tmp10
+= tmp0
- MULTIPLY(z3
, FIX(0.077722536)); /* c2-c4-c6 */
473 tmp12
+= tmp0
- MULTIPLY(z1
, FIX(2.470602249)); /* c2+c4+c6 */
474 tmp13
+= MULTIPLY(z2
, FIX(1.414213562)); /* c0 */
478 z1
= DEQUANTIZE(inptr
[DCTSIZE
*1], quantptr
[DCTSIZE
*1]);
479 z2
= DEQUANTIZE(inptr
[DCTSIZE
*3], quantptr
[DCTSIZE
*3]);
480 z3
= DEQUANTIZE(inptr
[DCTSIZE
*5], quantptr
[DCTSIZE
*5]);
482 tmp1
= MULTIPLY(z1
+ z2
, FIX(0.935414347)); /* (c3+c1-c5)/2 */
483 tmp2
= MULTIPLY(z1
- z2
, FIX(0.170262339)); /* (c3+c5-c1)/2 */
486 tmp2
= MULTIPLY(z2
+ z3
, - FIX(1.378756276)); /* -c1 */
488 z2
= MULTIPLY(z1
+ z3
, FIX(0.613604268)); /* c5 */
490 tmp2
+= z2
+ MULTIPLY(z3
, FIX(1.870828693)); /* c3+c1-c5 */
492 /* Final output stage */
494 wsptr
[7*0] = (int) RIGHT_SHIFT(tmp10
+ tmp0
, CONST_BITS
-PASS1_BITS
);
495 wsptr
[7*6] = (int) RIGHT_SHIFT(tmp10
- tmp0
, CONST_BITS
-PASS1_BITS
);
496 wsptr
[7*1] = (int) RIGHT_SHIFT(tmp11
+ tmp1
, CONST_BITS
-PASS1_BITS
);
497 wsptr
[7*5] = (int) RIGHT_SHIFT(tmp11
- tmp1
, CONST_BITS
-PASS1_BITS
);
498 wsptr
[7*2] = (int) RIGHT_SHIFT(tmp12
+ tmp2
, CONST_BITS
-PASS1_BITS
);
499 wsptr
[7*4] = (int) RIGHT_SHIFT(tmp12
- tmp2
, CONST_BITS
-PASS1_BITS
);
500 wsptr
[7*3] = (int) RIGHT_SHIFT(tmp13
, CONST_BITS
-PASS1_BITS
);
503 /* Pass 2: process 7 rows from work array, store into output array. */
506 for (ctr
= 0; ctr
< 7; ctr
++) {
507 outptr
= output_buf
[ctr
] + output_col
;
511 /* Add fudge factor here for final descale. */
512 tmp13
= (INT32
) wsptr
[0] + (ONE
<< (PASS1_BITS
+2));
513 tmp13
<<= CONST_BITS
;
515 z1
= (INT32
) wsptr
[2];
516 z2
= (INT32
) wsptr
[4];
517 z3
= (INT32
) wsptr
[6];
519 tmp10
= MULTIPLY(z2
- z3
, FIX(0.881747734)); /* c4 */
520 tmp12
= MULTIPLY(z1
- z2
, FIX(0.314692123)); /* c6 */
521 tmp11
= tmp10
+ tmp12
+ tmp13
- MULTIPLY(z2
, FIX(1.841218003)); /* c2+c4-c6 */
524 tmp0
= MULTIPLY(tmp0
, FIX(1.274162392)) + tmp13
; /* c2 */
525 tmp10
+= tmp0
- MULTIPLY(z3
, FIX(0.077722536)); /* c2-c4-c6 */
526 tmp12
+= tmp0
- MULTIPLY(z1
, FIX(2.470602249)); /* c2+c4+c6 */
527 tmp13
+= MULTIPLY(z2
, FIX(1.414213562)); /* c0 */
531 z1
= (INT32
) wsptr
[1];
532 z2
= (INT32
) wsptr
[3];
533 z3
= (INT32
) wsptr
[5];
535 tmp1
= MULTIPLY(z1
+ z2
, FIX(0.935414347)); /* (c3+c1-c5)/2 */
536 tmp2
= MULTIPLY(z1
- z2
, FIX(0.170262339)); /* (c3+c5-c1)/2 */
539 tmp2
= MULTIPLY(z2
+ z3
, - FIX(1.378756276)); /* -c1 */
541 z2
= MULTIPLY(z1
+ z3
, FIX(0.613604268)); /* c5 */
543 tmp2
+= z2
+ MULTIPLY(z3
, FIX(1.870828693)); /* c3+c1-c5 */
545 /* Final output stage */
547 outptr
[0] = range_limit
[(int) RIGHT_SHIFT(tmp10
+ tmp0
,
548 CONST_BITS
+PASS1_BITS
+3)
550 outptr
[6] = range_limit
[(int) RIGHT_SHIFT(tmp10
- tmp0
,
551 CONST_BITS
+PASS1_BITS
+3)
553 outptr
[1] = range_limit
[(int) RIGHT_SHIFT(tmp11
+ tmp1
,
554 CONST_BITS
+PASS1_BITS
+3)
556 outptr
[5] = range_limit
[(int) RIGHT_SHIFT(tmp11
- tmp1
,
557 CONST_BITS
+PASS1_BITS
+3)
559 outptr
[2] = range_limit
[(int) RIGHT_SHIFT(tmp12
+ tmp2
,
560 CONST_BITS
+PASS1_BITS
+3)
562 outptr
[4] = range_limit
[(int) RIGHT_SHIFT(tmp12
- tmp2
,
563 CONST_BITS
+PASS1_BITS
+3)
565 outptr
[3] = range_limit
[(int) RIGHT_SHIFT(tmp13
,
566 CONST_BITS
+PASS1_BITS
+3)
569 wsptr
+= 7; /* advance pointer to next row */
575 * Perform dequantization and inverse DCT on one block of coefficients,
576 * producing a reduced-size 6x6 output block.
578 * Optimized algorithm with 3 multiplications in the 1-D kernel.
579 * cK represents sqrt(2) * cos(K*pi/12).
583 jpeg_idct_6x6 (j_decompress_ptr cinfo
, jpeg_component_info
* compptr
,
585 JSAMPARRAY output_buf
, JDIMENSION output_col
)
587 INT32 tmp0
, tmp1
, tmp2
, tmp10
, tmp11
, tmp12
;
590 ISLOW_MULT_TYPE
* quantptr
;
593 JSAMPLE
*range_limit
= IDCT_range_limit(cinfo
);
595 int workspace
[6*6]; /* buffers data between passes */
598 /* Pass 1: process columns from input, store into work array. */
601 quantptr
= (ISLOW_MULT_TYPE
*) compptr
->dct_table
;
603 for (ctr
= 0; ctr
< 6; ctr
++, inptr
++, quantptr
++, wsptr
++) {
606 tmp0
= DEQUANTIZE(inptr
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]);
608 /* Add fudge factor here for final descale. */
609 tmp0
+= ONE
<< (CONST_BITS
-PASS1_BITS
-1);
610 tmp2
= DEQUANTIZE(inptr
[DCTSIZE
*4], quantptr
[DCTSIZE
*4]);
611 tmp10
= MULTIPLY(tmp2
, FIX(0.707106781)); /* c4 */
613 tmp11
= RIGHT_SHIFT(tmp0
- tmp10
- tmp10
, CONST_BITS
-PASS1_BITS
);
614 tmp10
= DEQUANTIZE(inptr
[DCTSIZE
*2], quantptr
[DCTSIZE
*2]);
615 tmp0
= MULTIPLY(tmp10
, FIX(1.224744871)); /* c2 */
621 z1
= DEQUANTIZE(inptr
[DCTSIZE
*1], quantptr
[DCTSIZE
*1]);
622 z2
= DEQUANTIZE(inptr
[DCTSIZE
*3], quantptr
[DCTSIZE
*3]);
623 z3
= DEQUANTIZE(inptr
[DCTSIZE
*5], quantptr
[DCTSIZE
*5]);
624 tmp1
= MULTIPLY(z1
+ z3
, FIX(0.366025404)); /* c5 */
625 tmp0
= tmp1
+ ((z1
+ z2
) << CONST_BITS
);
626 tmp2
= tmp1
+ ((z3
- z2
) << CONST_BITS
);
627 tmp1
= (z1
- z2
- z3
) << PASS1_BITS
;
629 /* Final output stage */
631 wsptr
[6*0] = (int) RIGHT_SHIFT(tmp10
+ tmp0
, CONST_BITS
-PASS1_BITS
);
632 wsptr
[6*5] = (int) RIGHT_SHIFT(tmp10
- tmp0
, CONST_BITS
-PASS1_BITS
);
633 wsptr
[6*1] = (int) (tmp11
+ tmp1
);
634 wsptr
[6*4] = (int) (tmp11
- tmp1
);
635 wsptr
[6*2] = (int) RIGHT_SHIFT(tmp12
+ tmp2
, CONST_BITS
-PASS1_BITS
);
636 wsptr
[6*3] = (int) RIGHT_SHIFT(tmp12
- tmp2
, CONST_BITS
-PASS1_BITS
);
639 /* Pass 2: process 6 rows from work array, store into output array. */
642 for (ctr
= 0; ctr
< 6; ctr
++) {
643 outptr
= output_buf
[ctr
] + output_col
;
647 /* Add fudge factor here for final descale. */
648 tmp0
= (INT32
) wsptr
[0] + (ONE
<< (PASS1_BITS
+2));
650 tmp2
= (INT32
) wsptr
[4];
651 tmp10
= MULTIPLY(tmp2
, FIX(0.707106781)); /* c4 */
653 tmp11
= tmp0
- tmp10
- tmp10
;
654 tmp10
= (INT32
) wsptr
[2];
655 tmp0
= MULTIPLY(tmp10
, FIX(1.224744871)); /* c2 */
661 z1
= (INT32
) wsptr
[1];
662 z2
= (INT32
) wsptr
[3];
663 z3
= (INT32
) wsptr
[5];
664 tmp1
= MULTIPLY(z1
+ z3
, FIX(0.366025404)); /* c5 */
665 tmp0
= tmp1
+ ((z1
+ z2
) << CONST_BITS
);
666 tmp2
= tmp1
+ ((z3
- z2
) << CONST_BITS
);
667 tmp1
= (z1
- z2
- z3
) << CONST_BITS
;
669 /* Final output stage */
671 outptr
[0] = range_limit
[(int) RIGHT_SHIFT(tmp10
+ tmp0
,
672 CONST_BITS
+PASS1_BITS
+3)
674 outptr
[5] = range_limit
[(int) RIGHT_SHIFT(tmp10
- tmp0
,
675 CONST_BITS
+PASS1_BITS
+3)
677 outptr
[1] = range_limit
[(int) RIGHT_SHIFT(tmp11
+ tmp1
,
678 CONST_BITS
+PASS1_BITS
+3)
680 outptr
[4] = range_limit
[(int) RIGHT_SHIFT(tmp11
- tmp1
,
681 CONST_BITS
+PASS1_BITS
+3)
683 outptr
[2] = range_limit
[(int) RIGHT_SHIFT(tmp12
+ tmp2
,
684 CONST_BITS
+PASS1_BITS
+3)
686 outptr
[3] = range_limit
[(int) RIGHT_SHIFT(tmp12
- tmp2
,
687 CONST_BITS
+PASS1_BITS
+3)
690 wsptr
+= 6; /* advance pointer to next row */
696 * Perform dequantization and inverse DCT on one block of coefficients,
697 * producing a reduced-size 5x5 output block.
699 * Optimized algorithm with 5 multiplications in the 1-D kernel.
700 * cK represents sqrt(2) * cos(K*pi/10).
704 jpeg_idct_5x5 (j_decompress_ptr cinfo
, jpeg_component_info
* compptr
,
706 JSAMPARRAY output_buf
, JDIMENSION output_col
)
708 INT32 tmp0
, tmp1
, tmp10
, tmp11
, tmp12
;
711 ISLOW_MULT_TYPE
* quantptr
;
714 JSAMPLE
*range_limit
= IDCT_range_limit(cinfo
);
716 int workspace
[5*5]; /* buffers data between passes */
719 /* Pass 1: process columns from input, store into work array. */
722 quantptr
= (ISLOW_MULT_TYPE
*) compptr
->dct_table
;
724 for (ctr
= 0; ctr
< 5; ctr
++, inptr
++, quantptr
++, wsptr
++) {
727 tmp12
= DEQUANTIZE(inptr
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]);
728 tmp12
<<= CONST_BITS
;
729 /* Add fudge factor here for final descale. */
730 tmp12
+= ONE
<< (CONST_BITS
-PASS1_BITS
-1);
731 tmp0
= DEQUANTIZE(inptr
[DCTSIZE
*2], quantptr
[DCTSIZE
*2]);
732 tmp1
= DEQUANTIZE(inptr
[DCTSIZE
*4], quantptr
[DCTSIZE
*4]);
733 z1
= MULTIPLY(tmp0
+ tmp1
, FIX(0.790569415)); /* (c2+c4)/2 */
734 z2
= MULTIPLY(tmp0
- tmp1
, FIX(0.353553391)); /* (c2-c4)/2 */
742 z2
= DEQUANTIZE(inptr
[DCTSIZE
*1], quantptr
[DCTSIZE
*1]);
743 z3
= DEQUANTIZE(inptr
[DCTSIZE
*3], quantptr
[DCTSIZE
*3]);
745 z1
= MULTIPLY(z2
+ z3
, FIX(0.831253876)); /* c3 */
746 tmp0
= z1
+ MULTIPLY(z2
, FIX(0.513743148)); /* c1-c3 */
747 tmp1
= z1
- MULTIPLY(z3
, FIX(2.176250899)); /* c1+c3 */
749 /* Final output stage */
751 wsptr
[5*0] = (int) RIGHT_SHIFT(tmp10
+ tmp0
, CONST_BITS
-PASS1_BITS
);
752 wsptr
[5*4] = (int) RIGHT_SHIFT(tmp10
- tmp0
, CONST_BITS
-PASS1_BITS
);
753 wsptr
[5*1] = (int) RIGHT_SHIFT(tmp11
+ tmp1
, CONST_BITS
-PASS1_BITS
);
754 wsptr
[5*3] = (int) RIGHT_SHIFT(tmp11
- tmp1
, CONST_BITS
-PASS1_BITS
);
755 wsptr
[5*2] = (int) RIGHT_SHIFT(tmp12
, CONST_BITS
-PASS1_BITS
);
758 /* Pass 2: process 5 rows from work array, store into output array. */
761 for (ctr
= 0; ctr
< 5; ctr
++) {
762 outptr
= output_buf
[ctr
] + output_col
;
766 /* Add fudge factor here for final descale. */
767 tmp12
= (INT32
) wsptr
[0] + (ONE
<< (PASS1_BITS
+2));
768 tmp12
<<= CONST_BITS
;
769 tmp0
= (INT32
) wsptr
[2];
770 tmp1
= (INT32
) wsptr
[4];
771 z1
= MULTIPLY(tmp0
+ tmp1
, FIX(0.790569415)); /* (c2+c4)/2 */
772 z2
= MULTIPLY(tmp0
- tmp1
, FIX(0.353553391)); /* (c2-c4)/2 */
780 z2
= (INT32
) wsptr
[1];
781 z3
= (INT32
) wsptr
[3];
783 z1
= MULTIPLY(z2
+ z3
, FIX(0.831253876)); /* c3 */
784 tmp0
= z1
+ MULTIPLY(z2
, FIX(0.513743148)); /* c1-c3 */
785 tmp1
= z1
- MULTIPLY(z3
, FIX(2.176250899)); /* c1+c3 */
787 /* Final output stage */
789 outptr
[0] = range_limit
[(int) RIGHT_SHIFT(tmp10
+ tmp0
,
790 CONST_BITS
+PASS1_BITS
+3)
792 outptr
[4] = range_limit
[(int) RIGHT_SHIFT(tmp10
- tmp0
,
793 CONST_BITS
+PASS1_BITS
+3)
795 outptr
[1] = range_limit
[(int) RIGHT_SHIFT(tmp11
+ tmp1
,
796 CONST_BITS
+PASS1_BITS
+3)
798 outptr
[3] = range_limit
[(int) RIGHT_SHIFT(tmp11
- tmp1
,
799 CONST_BITS
+PASS1_BITS
+3)
801 outptr
[2] = range_limit
[(int) RIGHT_SHIFT(tmp12
,
802 CONST_BITS
+PASS1_BITS
+3)
805 wsptr
+= 5; /* advance pointer to next row */
811 * Perform dequantization and inverse DCT on one block of coefficients,
812 * producing a reduced-size 4x4 output block.
814 * Optimized algorithm with 3 multiplications in the 1-D kernel.
815 * cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point IDCT].
819 jpeg_idct_4x4 (j_decompress_ptr cinfo
, jpeg_component_info
* compptr
,
821 JSAMPARRAY output_buf
, JDIMENSION output_col
)
823 INT32 tmp0
, tmp2
, tmp10
, tmp12
;
826 ISLOW_MULT_TYPE
* quantptr
;
829 JSAMPLE
*range_limit
= IDCT_range_limit(cinfo
);
831 int workspace
[4*4]; /* buffers data between passes */
834 /* Pass 1: process columns from input, store into work array. */
837 quantptr
= (ISLOW_MULT_TYPE
*) compptr
->dct_table
;
839 for (ctr
= 0; ctr
< 4; ctr
++, inptr
++, quantptr
++, wsptr
++) {
842 tmp0
= DEQUANTIZE(inptr
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]);
843 tmp2
= DEQUANTIZE(inptr
[DCTSIZE
*2], quantptr
[DCTSIZE
*2]);
845 tmp10
= (tmp0
+ tmp2
) << PASS1_BITS
;
846 tmp12
= (tmp0
- tmp2
) << PASS1_BITS
;
849 /* Same rotation as in the even part of the 8x8 LL&M IDCT */
851 z2
= DEQUANTIZE(inptr
[DCTSIZE
*1], quantptr
[DCTSIZE
*1]);
852 z3
= DEQUANTIZE(inptr
[DCTSIZE
*3], quantptr
[DCTSIZE
*3]);
854 z1
= MULTIPLY(z2
+ z3
, FIX_0_541196100
); /* c6 */
855 /* Add fudge factor here for final descale. */
856 z1
+= ONE
<< (CONST_BITS
-PASS1_BITS
-1);
857 tmp0
= RIGHT_SHIFT(z1
+ MULTIPLY(z2
, FIX_0_765366865
), /* c2-c6 */
858 CONST_BITS
-PASS1_BITS
);
859 tmp2
= RIGHT_SHIFT(z1
- MULTIPLY(z3
, FIX_1_847759065
), /* c2+c6 */
860 CONST_BITS
-PASS1_BITS
);
862 /* Final output stage */
864 wsptr
[4*0] = (int) (tmp10
+ tmp0
);
865 wsptr
[4*3] = (int) (tmp10
- tmp0
);
866 wsptr
[4*1] = (int) (tmp12
+ tmp2
);
867 wsptr
[4*2] = (int) (tmp12
- tmp2
);
870 /* Pass 2: process 4 rows from work array, store into output array. */
873 for (ctr
= 0; ctr
< 4; ctr
++) {
874 outptr
= output_buf
[ctr
] + output_col
;
878 /* Add fudge factor here for final descale. */
879 tmp0
= (INT32
) wsptr
[0] + (ONE
<< (PASS1_BITS
+2));
880 tmp2
= (INT32
) wsptr
[2];
882 tmp10
= (tmp0
+ tmp2
) << CONST_BITS
;
883 tmp12
= (tmp0
- tmp2
) << CONST_BITS
;
886 /* Same rotation as in the even part of the 8x8 LL&M IDCT */
888 z2
= (INT32
) wsptr
[1];
889 z3
= (INT32
) wsptr
[3];
891 z1
= MULTIPLY(z2
+ z3
, FIX_0_541196100
); /* c6 */
892 tmp0
= z1
+ MULTIPLY(z2
, FIX_0_765366865
); /* c2-c6 */
893 tmp2
= z1
- MULTIPLY(z3
, FIX_1_847759065
); /* c2+c6 */
895 /* Final output stage */
897 outptr
[0] = range_limit
[(int) RIGHT_SHIFT(tmp10
+ tmp0
,
898 CONST_BITS
+PASS1_BITS
+3)
900 outptr
[3] = range_limit
[(int) RIGHT_SHIFT(tmp10
- tmp0
,
901 CONST_BITS
+PASS1_BITS
+3)
903 outptr
[1] = range_limit
[(int) RIGHT_SHIFT(tmp12
+ tmp2
,
904 CONST_BITS
+PASS1_BITS
+3)
906 outptr
[2] = range_limit
[(int) RIGHT_SHIFT(tmp12
- tmp2
,
907 CONST_BITS
+PASS1_BITS
+3)
910 wsptr
+= 4; /* advance pointer to next row */
916 * Perform dequantization and inverse DCT on one block of coefficients,
917 * producing a reduced-size 3x3 output block.
919 * Optimized algorithm with 2 multiplications in the 1-D kernel.
920 * cK represents sqrt(2) * cos(K*pi/6).
924 jpeg_idct_3x3 (j_decompress_ptr cinfo
, jpeg_component_info
* compptr
,
926 JSAMPARRAY output_buf
, JDIMENSION output_col
)
928 INT32 tmp0
, tmp2
, tmp10
, tmp12
;
930 ISLOW_MULT_TYPE
* quantptr
;
933 JSAMPLE
*range_limit
= IDCT_range_limit(cinfo
);
935 int workspace
[3*3]; /* buffers data between passes */
938 /* Pass 1: process columns from input, store into work array. */
941 quantptr
= (ISLOW_MULT_TYPE
*) compptr
->dct_table
;
943 for (ctr
= 0; ctr
< 3; ctr
++, inptr
++, quantptr
++, wsptr
++) {
946 tmp0
= DEQUANTIZE(inptr
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]);
948 /* Add fudge factor here for final descale. */
949 tmp0
+= ONE
<< (CONST_BITS
-PASS1_BITS
-1);
950 tmp2
= DEQUANTIZE(inptr
[DCTSIZE
*2], quantptr
[DCTSIZE
*2]);
951 tmp12
= MULTIPLY(tmp2
, FIX(0.707106781)); /* c2 */
952 tmp10
= tmp0
+ tmp12
;
953 tmp2
= tmp0
- tmp12
- tmp12
;
957 tmp12
= DEQUANTIZE(inptr
[DCTSIZE
*1], quantptr
[DCTSIZE
*1]);
958 tmp0
= MULTIPLY(tmp12
, FIX(1.224744871)); /* c1 */
960 /* Final output stage */
962 wsptr
[3*0] = (int) RIGHT_SHIFT(tmp10
+ tmp0
, CONST_BITS
-PASS1_BITS
);
963 wsptr
[3*2] = (int) RIGHT_SHIFT(tmp10
- tmp0
, CONST_BITS
-PASS1_BITS
);
964 wsptr
[3*1] = (int) RIGHT_SHIFT(tmp2
, CONST_BITS
-PASS1_BITS
);
967 /* Pass 2: process 3 rows from work array, store into output array. */
970 for (ctr
= 0; ctr
< 3; ctr
++) {
971 outptr
= output_buf
[ctr
] + output_col
;
975 /* Add fudge factor here for final descale. */
976 tmp0
= (INT32
) wsptr
[0] + (ONE
<< (PASS1_BITS
+2));
978 tmp2
= (INT32
) wsptr
[2];
979 tmp12
= MULTIPLY(tmp2
, FIX(0.707106781)); /* c2 */
980 tmp10
= tmp0
+ tmp12
;
981 tmp2
= tmp0
- tmp12
- tmp12
;
985 tmp12
= (INT32
) wsptr
[1];
986 tmp0
= MULTIPLY(tmp12
, FIX(1.224744871)); /* c1 */
988 /* Final output stage */
990 outptr
[0] = range_limit
[(int) RIGHT_SHIFT(tmp10
+ tmp0
,
991 CONST_BITS
+PASS1_BITS
+3)
993 outptr
[2] = range_limit
[(int) RIGHT_SHIFT(tmp10
- tmp0
,
994 CONST_BITS
+PASS1_BITS
+3)
996 outptr
[1] = range_limit
[(int) RIGHT_SHIFT(tmp2
,
997 CONST_BITS
+PASS1_BITS
+3)
1000 wsptr
+= 3; /* advance pointer to next row */
1006 * Perform dequantization and inverse DCT on one block of coefficients,
1007 * producing a reduced-size 2x2 output block.
1009 * Multiplication-less algorithm.
1013 jpeg_idct_2x2 (j_decompress_ptr cinfo
, jpeg_component_info
* compptr
,
1014 JCOEFPTR coef_block
,
1015 JSAMPARRAY output_buf
, JDIMENSION output_col
)
1017 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp4
, tmp5
;
1018 ISLOW_MULT_TYPE
* quantptr
;
1020 JSAMPLE
*range_limit
= IDCT_range_limit(cinfo
);
1023 /* Pass 1: process columns from input. */
1025 quantptr
= (ISLOW_MULT_TYPE
*) compptr
->dct_table
;
1028 tmp4
= DEQUANTIZE(coef_block
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]);
1029 tmp5
= DEQUANTIZE(coef_block
[DCTSIZE
*1], quantptr
[DCTSIZE
*1]);
1030 /* Add fudge factor here for final descale. */
1037 tmp4
= DEQUANTIZE(coef_block
[DCTSIZE
*0+1], quantptr
[DCTSIZE
*0+1]);
1038 tmp5
= DEQUANTIZE(coef_block
[DCTSIZE
*1+1], quantptr
[DCTSIZE
*1+1]);
1043 /* Pass 2: process 2 rows, store into output array. */
1046 outptr
= output_buf
[0] + output_col
;
1048 outptr
[0] = range_limit
[(int) RIGHT_SHIFT(tmp0
+ tmp1
, 3) & RANGE_MASK
];
1049 outptr
[1] = range_limit
[(int) RIGHT_SHIFT(tmp0
- tmp1
, 3) & RANGE_MASK
];
1052 outptr
= output_buf
[1] + output_col
;
1054 outptr
[0] = range_limit
[(int) RIGHT_SHIFT(tmp2
+ tmp3
, 3) & RANGE_MASK
];
1055 outptr
[1] = range_limit
[(int) RIGHT_SHIFT(tmp2
- tmp3
, 3) & RANGE_MASK
];
1060 * Perform dequantization and inverse DCT on one block of coefficients,
1061 * producing a reduced-size 1x1 output block.
1063 * We hardly need an inverse DCT routine for this: just take the
1064 * average pixel value, which is one-eighth of the DC coefficient.
1068 jpeg_idct_1x1 (j_decompress_ptr cinfo
, jpeg_component_info
* compptr
,
1069 JCOEFPTR coef_block
,
1070 JSAMPARRAY output_buf
, JDIMENSION output_col
)
1073 ISLOW_MULT_TYPE
* quantptr
;
1074 JSAMPLE
*range_limit
= IDCT_range_limit(cinfo
);
1077 /* 1x1 is trivial: just take the DC coefficient divided by 8. */
1078 quantptr
= (ISLOW_MULT_TYPE
*) compptr
->dct_table
;
1079 dcval
= DEQUANTIZE(coef_block
[0], quantptr
[0]);
1080 dcval
= (int) DESCALE((INT32
) dcval
, 3);
1082 output_buf
[0][output_col
] = range_limit
[dcval
& RANGE_MASK
];
1087 * Perform dequantization and inverse DCT on one block of coefficients,
1088 * producing a 9x9 output block.
1090 * Optimized algorithm with 10 multiplications in the 1-D kernel.
1091 * cK represents sqrt(2) * cos(K*pi/18).
1095 jpeg_idct_9x9 (j_decompress_ptr cinfo
, jpeg_component_info
* compptr
,
1096 JCOEFPTR coef_block
,
1097 JSAMPARRAY output_buf
, JDIMENSION output_col
)
1099 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp10
, tmp11
, tmp12
, tmp13
, tmp14
;
1100 INT32 z1
, z2
, z3
, z4
;
1102 ISLOW_MULT_TYPE
* quantptr
;
1105 JSAMPLE
*range_limit
= IDCT_range_limit(cinfo
);
1107 int workspace
[8*9]; /* buffers data between passes */
1110 /* Pass 1: process columns from input, store into work array. */
1113 quantptr
= (ISLOW_MULT_TYPE
*) compptr
->dct_table
;
1115 for (ctr
= 0; ctr
< 8; ctr
++, inptr
++, quantptr
++, wsptr
++) {
1118 tmp0
= DEQUANTIZE(inptr
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]);
1119 tmp0
<<= CONST_BITS
;
1120 /* Add fudge factor here for final descale. */
1121 tmp0
+= ONE
<< (CONST_BITS
-PASS1_BITS
-1);
1123 z1
= DEQUANTIZE(inptr
[DCTSIZE
*2], quantptr
[DCTSIZE
*2]);
1124 z2
= DEQUANTIZE(inptr
[DCTSIZE
*4], quantptr
[DCTSIZE
*4]);
1125 z3
= DEQUANTIZE(inptr
[DCTSIZE
*6], quantptr
[DCTSIZE
*6]);
1127 tmp3
= MULTIPLY(z3
, FIX(0.707106781)); /* c6 */
1129 tmp2
= tmp0
- tmp3
- tmp3
;
1131 tmp0
= MULTIPLY(z1
- z2
, FIX(0.707106781)); /* c6 */
1132 tmp11
= tmp2
+ tmp0
;
1133 tmp14
= tmp2
- tmp0
- tmp0
;
1135 tmp0
= MULTIPLY(z1
+ z2
, FIX(1.328926049)); /* c2 */
1136 tmp2
= MULTIPLY(z1
, FIX(1.083350441)); /* c4 */
1137 tmp3
= MULTIPLY(z2
, FIX(0.245575608)); /* c8 */
1139 tmp10
= tmp1
+ tmp0
- tmp3
;
1140 tmp12
= tmp1
- tmp0
+ tmp2
;
1141 tmp13
= tmp1
- tmp2
+ tmp3
;
1145 z1
= DEQUANTIZE(inptr
[DCTSIZE
*1], quantptr
[DCTSIZE
*1]);
1146 z2
= DEQUANTIZE(inptr
[DCTSIZE
*3], quantptr
[DCTSIZE
*3]);
1147 z3
= DEQUANTIZE(inptr
[DCTSIZE
*5], quantptr
[DCTSIZE
*5]);
1148 z4
= DEQUANTIZE(inptr
[DCTSIZE
*7], quantptr
[DCTSIZE
*7]);
1150 z2
= MULTIPLY(z2
, - FIX(1.224744871)); /* -c3 */
1152 tmp2
= MULTIPLY(z1
+ z3
, FIX(0.909038955)); /* c5 */
1153 tmp3
= MULTIPLY(z1
+ z4
, FIX(0.483689525)); /* c7 */
1154 tmp0
= tmp2
+ tmp3
- z2
;
1155 tmp1
= MULTIPLY(z3
- z4
, FIX(1.392728481)); /* c1 */
1158 tmp1
= MULTIPLY(z1
- z3
- z4
, FIX(1.224744871)); /* c3 */
1160 /* Final output stage */
1162 wsptr
[8*0] = (int) RIGHT_SHIFT(tmp10
+ tmp0
, CONST_BITS
-PASS1_BITS
);
1163 wsptr
[8*8] = (int) RIGHT_SHIFT(tmp10
- tmp0
, CONST_BITS
-PASS1_BITS
);
1164 wsptr
[8*1] = (int) RIGHT_SHIFT(tmp11
+ tmp1
, CONST_BITS
-PASS1_BITS
);
1165 wsptr
[8*7] = (int) RIGHT_SHIFT(tmp11
- tmp1
, CONST_BITS
-PASS1_BITS
);
1166 wsptr
[8*2] = (int) RIGHT_SHIFT(tmp12
+ tmp2
, CONST_BITS
-PASS1_BITS
);
1167 wsptr
[8*6] = (int) RIGHT_SHIFT(tmp12
- tmp2
, CONST_BITS
-PASS1_BITS
);
1168 wsptr
[8*3] = (int) RIGHT_SHIFT(tmp13
+ tmp3
, CONST_BITS
-PASS1_BITS
);
1169 wsptr
[8*5] = (int) RIGHT_SHIFT(tmp13
- tmp3
, CONST_BITS
-PASS1_BITS
);
1170 wsptr
[8*4] = (int) RIGHT_SHIFT(tmp14
, CONST_BITS
-PASS1_BITS
);
1173 /* Pass 2: process 9 rows from work array, store into output array. */
1176 for (ctr
= 0; ctr
< 9; ctr
++) {
1177 outptr
= output_buf
[ctr
] + output_col
;
1181 /* Add fudge factor here for final descale. */
1182 tmp0
= (INT32
) wsptr
[0] + (ONE
<< (PASS1_BITS
+2));
1183 tmp0
<<= CONST_BITS
;
1185 z1
= (INT32
) wsptr
[2];
1186 z2
= (INT32
) wsptr
[4];
1187 z3
= (INT32
) wsptr
[6];
1189 tmp3
= MULTIPLY(z3
, FIX(0.707106781)); /* c6 */
1191 tmp2
= tmp0
- tmp3
- tmp3
;
1193 tmp0
= MULTIPLY(z1
- z2
, FIX(0.707106781)); /* c6 */
1194 tmp11
= tmp2
+ tmp0
;
1195 tmp14
= tmp2
- tmp0
- tmp0
;
1197 tmp0
= MULTIPLY(z1
+ z2
, FIX(1.328926049)); /* c2 */
1198 tmp2
= MULTIPLY(z1
, FIX(1.083350441)); /* c4 */
1199 tmp3
= MULTIPLY(z2
, FIX(0.245575608)); /* c8 */
1201 tmp10
= tmp1
+ tmp0
- tmp3
;
1202 tmp12
= tmp1
- tmp0
+ tmp2
;
1203 tmp13
= tmp1
- tmp2
+ tmp3
;
1207 z1
= (INT32
) wsptr
[1];
1208 z2
= (INT32
) wsptr
[3];
1209 z3
= (INT32
) wsptr
[5];
1210 z4
= (INT32
) wsptr
[7];
1212 z2
= MULTIPLY(z2
, - FIX(1.224744871)); /* -c3 */
1214 tmp2
= MULTIPLY(z1
+ z3
, FIX(0.909038955)); /* c5 */
1215 tmp3
= MULTIPLY(z1
+ z4
, FIX(0.483689525)); /* c7 */
1216 tmp0
= tmp2
+ tmp3
- z2
;
1217 tmp1
= MULTIPLY(z3
- z4
, FIX(1.392728481)); /* c1 */
1220 tmp1
= MULTIPLY(z1
- z3
- z4
, FIX(1.224744871)); /* c3 */
1222 /* Final output stage */
1224 outptr
[0] = range_limit
[(int) RIGHT_SHIFT(tmp10
+ tmp0
,
1225 CONST_BITS
+PASS1_BITS
+3)
1227 outptr
[8] = range_limit
[(int) RIGHT_SHIFT(tmp10
- tmp0
,
1228 CONST_BITS
+PASS1_BITS
+3)
1230 outptr
[1] = range_limit
[(int) RIGHT_SHIFT(tmp11
+ tmp1
,
1231 CONST_BITS
+PASS1_BITS
+3)
1233 outptr
[7] = range_limit
[(int) RIGHT_SHIFT(tmp11
- tmp1
,
1234 CONST_BITS
+PASS1_BITS
+3)
1236 outptr
[2] = range_limit
[(int) RIGHT_SHIFT(tmp12
+ tmp2
,
1237 CONST_BITS
+PASS1_BITS
+3)
1239 outptr
[6] = range_limit
[(int) RIGHT_SHIFT(tmp12
- tmp2
,
1240 CONST_BITS
+PASS1_BITS
+3)
1242 outptr
[3] = range_limit
[(int) RIGHT_SHIFT(tmp13
+ tmp3
,
1243 CONST_BITS
+PASS1_BITS
+3)
1245 outptr
[5] = range_limit
[(int) RIGHT_SHIFT(tmp13
- tmp3
,
1246 CONST_BITS
+PASS1_BITS
+3)
1248 outptr
[4] = range_limit
[(int) RIGHT_SHIFT(tmp14
,
1249 CONST_BITS
+PASS1_BITS
+3)
1252 wsptr
+= 8; /* advance pointer to next row */
1258 * Perform dequantization and inverse DCT on one block of coefficients,
1259 * producing a 10x10 output block.
1261 * Optimized algorithm with 12 multiplications in the 1-D kernel.
1262 * cK represents sqrt(2) * cos(K*pi/20).
1266 jpeg_idct_10x10 (j_decompress_ptr cinfo
, jpeg_component_info
* compptr
,
1267 JCOEFPTR coef_block
,
1268 JSAMPARRAY output_buf
, JDIMENSION output_col
)
1270 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
;
1271 INT32 tmp20
, tmp21
, tmp22
, tmp23
, tmp24
;
1272 INT32 z1
, z2
, z3
, z4
, z5
;
1274 ISLOW_MULT_TYPE
* quantptr
;
1277 JSAMPLE
*range_limit
= IDCT_range_limit(cinfo
);
1279 int workspace
[8*10]; /* buffers data between passes */
1282 /* Pass 1: process columns from input, store into work array. */
1285 quantptr
= (ISLOW_MULT_TYPE
*) compptr
->dct_table
;
1287 for (ctr
= 0; ctr
< 8; ctr
++, inptr
++, quantptr
++, wsptr
++) {
1290 z3
= DEQUANTIZE(inptr
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]);
1292 /* Add fudge factor here for final descale. */
1293 z3
+= ONE
<< (CONST_BITS
-PASS1_BITS
-1);
1294 z4
= DEQUANTIZE(inptr
[DCTSIZE
*4], quantptr
[DCTSIZE
*4]);
1295 z1
= MULTIPLY(z4
, FIX(1.144122806)); /* c4 */
1296 z2
= MULTIPLY(z4
, FIX(0.437016024)); /* c8 */
1300 tmp22
= RIGHT_SHIFT(z3
- ((z1
- z2
) << 1), /* c0 = (c4-c8)*2 */
1301 CONST_BITS
-PASS1_BITS
);
1303 z2
= DEQUANTIZE(inptr
[DCTSIZE
*2], quantptr
[DCTSIZE
*2]);
1304 z3
= DEQUANTIZE(inptr
[DCTSIZE
*6], quantptr
[DCTSIZE
*6]);
1306 z1
= MULTIPLY(z2
+ z3
, FIX(0.831253876)); /* c6 */
1307 tmp12
= z1
+ MULTIPLY(z2
, FIX(0.513743148)); /* c2-c6 */
1308 tmp13
= z1
- MULTIPLY(z3
, FIX(2.176250899)); /* c2+c6 */
1310 tmp20
= tmp10
+ tmp12
;
1311 tmp24
= tmp10
- tmp12
;
1312 tmp21
= tmp11
+ tmp13
;
1313 tmp23
= tmp11
- tmp13
;
1317 z1
= DEQUANTIZE(inptr
[DCTSIZE
*1], quantptr
[DCTSIZE
*1]);
1318 z2
= DEQUANTIZE(inptr
[DCTSIZE
*3], quantptr
[DCTSIZE
*3]);
1319 z3
= DEQUANTIZE(inptr
[DCTSIZE
*5], quantptr
[DCTSIZE
*5]);
1320 z4
= DEQUANTIZE(inptr
[DCTSIZE
*7], quantptr
[DCTSIZE
*7]);
1325 tmp12
= MULTIPLY(tmp13
, FIX(0.309016994)); /* (c3-c7)/2 */
1326 z5
= z3
<< CONST_BITS
;
1328 z2
= MULTIPLY(tmp11
, FIX(0.951056516)); /* (c3+c7)/2 */
1331 tmp10
= MULTIPLY(z1
, FIX(1.396802247)) + z2
+ z4
; /* c1 */
1332 tmp14
= MULTIPLY(z1
, FIX(0.221231742)) - z2
+ z4
; /* c9 */
1334 z2
= MULTIPLY(tmp11
, FIX(0.587785252)); /* (c1-c9)/2 */
1335 z4
= z5
- tmp12
- (tmp13
<< (CONST_BITS
- 1));
1337 tmp12
= (z1
- tmp13
- z3
) << PASS1_BITS
;
1339 tmp11
= MULTIPLY(z1
, FIX(1.260073511)) - z2
- z4
; /* c3 */
1340 tmp13
= MULTIPLY(z1
, FIX(0.642039522)) - z2
+ z4
; /* c7 */
1342 /* Final output stage */
1344 wsptr
[8*0] = (int) RIGHT_SHIFT(tmp20
+ tmp10
, CONST_BITS
-PASS1_BITS
);
1345 wsptr
[8*9] = (int) RIGHT_SHIFT(tmp20
- tmp10
, CONST_BITS
-PASS1_BITS
);
1346 wsptr
[8*1] = (int) RIGHT_SHIFT(tmp21
+ tmp11
, CONST_BITS
-PASS1_BITS
);
1347 wsptr
[8*8] = (int) RIGHT_SHIFT(tmp21
- tmp11
, CONST_BITS
-PASS1_BITS
);
1348 wsptr
[8*2] = (int) (tmp22
+ tmp12
);
1349 wsptr
[8*7] = (int) (tmp22
- tmp12
);
1350 wsptr
[8*3] = (int) RIGHT_SHIFT(tmp23
+ tmp13
, CONST_BITS
-PASS1_BITS
);
1351 wsptr
[8*6] = (int) RIGHT_SHIFT(tmp23
- tmp13
, CONST_BITS
-PASS1_BITS
);
1352 wsptr
[8*4] = (int) RIGHT_SHIFT(tmp24
+ tmp14
, CONST_BITS
-PASS1_BITS
);
1353 wsptr
[8*5] = (int) RIGHT_SHIFT(tmp24
- tmp14
, CONST_BITS
-PASS1_BITS
);
1356 /* Pass 2: process 10 rows from work array, store into output array. */
1359 for (ctr
= 0; ctr
< 10; ctr
++) {
1360 outptr
= output_buf
[ctr
] + output_col
;
1364 /* Add fudge factor here for final descale. */
1365 z3
= (INT32
) wsptr
[0] + (ONE
<< (PASS1_BITS
+2));
1367 z4
= (INT32
) wsptr
[4];
1368 z1
= MULTIPLY(z4
, FIX(1.144122806)); /* c4 */
1369 z2
= MULTIPLY(z4
, FIX(0.437016024)); /* c8 */
1373 tmp22
= z3
- ((z1
- z2
) << 1); /* c0 = (c4-c8)*2 */
1375 z2
= (INT32
) wsptr
[2];
1376 z3
= (INT32
) wsptr
[6];
1378 z1
= MULTIPLY(z2
+ z3
, FIX(0.831253876)); /* c6 */
1379 tmp12
= z1
+ MULTIPLY(z2
, FIX(0.513743148)); /* c2-c6 */
1380 tmp13
= z1
- MULTIPLY(z3
, FIX(2.176250899)); /* c2+c6 */
1382 tmp20
= tmp10
+ tmp12
;
1383 tmp24
= tmp10
- tmp12
;
1384 tmp21
= tmp11
+ tmp13
;
1385 tmp23
= tmp11
- tmp13
;
1389 z1
= (INT32
) wsptr
[1];
1390 z2
= (INT32
) wsptr
[3];
1391 z3
= (INT32
) wsptr
[5];
1393 z4
= (INT32
) wsptr
[7];
1398 tmp12
= MULTIPLY(tmp13
, FIX(0.309016994)); /* (c3-c7)/2 */
1400 z2
= MULTIPLY(tmp11
, FIX(0.951056516)); /* (c3+c7)/2 */
1403 tmp10
= MULTIPLY(z1
, FIX(1.396802247)) + z2
+ z4
; /* c1 */
1404 tmp14
= MULTIPLY(z1
, FIX(0.221231742)) - z2
+ z4
; /* c9 */
1406 z2
= MULTIPLY(tmp11
, FIX(0.587785252)); /* (c1-c9)/2 */
1407 z4
= z3
- tmp12
- (tmp13
<< (CONST_BITS
- 1));
1409 tmp12
= ((z1
- tmp13
) << CONST_BITS
) - z3
;
1411 tmp11
= MULTIPLY(z1
, FIX(1.260073511)) - z2
- z4
; /* c3 */
1412 tmp13
= MULTIPLY(z1
, FIX(0.642039522)) - z2
+ z4
; /* c7 */
1414 /* Final output stage */
1416 outptr
[0] = range_limit
[(int) RIGHT_SHIFT(tmp20
+ tmp10
,
1417 CONST_BITS
+PASS1_BITS
+3)
1419 outptr
[9] = range_limit
[(int) RIGHT_SHIFT(tmp20
- tmp10
,
1420 CONST_BITS
+PASS1_BITS
+3)
1422 outptr
[1] = range_limit
[(int) RIGHT_SHIFT(tmp21
+ tmp11
,
1423 CONST_BITS
+PASS1_BITS
+3)
1425 outptr
[8] = range_limit
[(int) RIGHT_SHIFT(tmp21
- tmp11
,
1426 CONST_BITS
+PASS1_BITS
+3)
1428 outptr
[2] = range_limit
[(int) RIGHT_SHIFT(tmp22
+ tmp12
,
1429 CONST_BITS
+PASS1_BITS
+3)
1431 outptr
[7] = range_limit
[(int) RIGHT_SHIFT(tmp22
- tmp12
,
1432 CONST_BITS
+PASS1_BITS
+3)
1434 outptr
[3] = range_limit
[(int) RIGHT_SHIFT(tmp23
+ tmp13
,
1435 CONST_BITS
+PASS1_BITS
+3)
1437 outptr
[6] = range_limit
[(int) RIGHT_SHIFT(tmp23
- tmp13
,
1438 CONST_BITS
+PASS1_BITS
+3)
1440 outptr
[4] = range_limit
[(int) RIGHT_SHIFT(tmp24
+ tmp14
,
1441 CONST_BITS
+PASS1_BITS
+3)
1443 outptr
[5] = range_limit
[(int) RIGHT_SHIFT(tmp24
- tmp14
,
1444 CONST_BITS
+PASS1_BITS
+3)
1447 wsptr
+= 8; /* advance pointer to next row */
1453 * Perform dequantization and inverse DCT on one block of coefficients,
1454 * producing a 11x11 output block.
1456 * Optimized algorithm with 24 multiplications in the 1-D kernel.
1457 * cK represents sqrt(2) * cos(K*pi/22).
1461 jpeg_idct_11x11 (j_decompress_ptr cinfo
, jpeg_component_info
* compptr
,
1462 JCOEFPTR coef_block
,
1463 JSAMPARRAY output_buf
, JDIMENSION output_col
)
1465 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
;
1466 INT32 tmp20
, tmp21
, tmp22
, tmp23
, tmp24
, tmp25
;
1467 INT32 z1
, z2
, z3
, z4
;
1469 ISLOW_MULT_TYPE
* quantptr
;
1472 JSAMPLE
*range_limit
= IDCT_range_limit(cinfo
);
1474 int workspace
[8*11]; /* buffers data between passes */
1477 /* Pass 1: process columns from input, store into work array. */
1480 quantptr
= (ISLOW_MULT_TYPE
*) compptr
->dct_table
;
1482 for (ctr
= 0; ctr
< 8; ctr
++, inptr
++, quantptr
++, wsptr
++) {
1485 tmp10
= DEQUANTIZE(inptr
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]);
1486 tmp10
<<= CONST_BITS
;
1487 /* Add fudge factor here for final descale. */
1488 tmp10
+= ONE
<< (CONST_BITS
-PASS1_BITS
-1);
1490 z1
= DEQUANTIZE(inptr
[DCTSIZE
*2], quantptr
[DCTSIZE
*2]);
1491 z2
= DEQUANTIZE(inptr
[DCTSIZE
*4], quantptr
[DCTSIZE
*4]);
1492 z3
= DEQUANTIZE(inptr
[DCTSIZE
*6], quantptr
[DCTSIZE
*6]);
1494 tmp20
= MULTIPLY(z2
- z3
, FIX(2.546640132)); /* c2+c4 */
1495 tmp23
= MULTIPLY(z2
- z1
, FIX(0.430815045)); /* c2-c6 */
1497 tmp24
= MULTIPLY(z4
, - FIX(1.155664402)); /* -(c2-c10) */
1499 tmp25
= tmp10
+ MULTIPLY(z4
, FIX(1.356927976)); /* c2 */
1500 tmp21
= tmp20
+ tmp23
+ tmp25
-
1501 MULTIPLY(z2
, FIX(1.821790775)); /* c2+c4+c10-c6 */
1502 tmp20
+= tmp25
+ MULTIPLY(z3
, FIX(2.115825087)); /* c4+c6 */
1503 tmp23
+= tmp25
- MULTIPLY(z1
, FIX(1.513598477)); /* c6+c8 */
1505 tmp22
= tmp24
- MULTIPLY(z3
, FIX(0.788749120)); /* c8+c10 */
1506 tmp24
+= MULTIPLY(z2
, FIX(1.944413522)) - /* c2+c8 */
1507 MULTIPLY(z1
, FIX(1.390975730)); /* c4+c10 */
1508 tmp25
= tmp10
- MULTIPLY(z4
, FIX(1.414213562)); /* c0 */
1512 z1
= DEQUANTIZE(inptr
[DCTSIZE
*1], quantptr
[DCTSIZE
*1]);
1513 z2
= DEQUANTIZE(inptr
[DCTSIZE
*3], quantptr
[DCTSIZE
*3]);
1514 z3
= DEQUANTIZE(inptr
[DCTSIZE
*5], quantptr
[DCTSIZE
*5]);
1515 z4
= DEQUANTIZE(inptr
[DCTSIZE
*7], quantptr
[DCTSIZE
*7]);
1518 tmp14
= MULTIPLY(tmp11
+ z3
+ z4
, FIX(0.398430003)); /* c9 */
1519 tmp11
= MULTIPLY(tmp11
, FIX(0.887983902)); /* c3-c9 */
1520 tmp12
= MULTIPLY(z1
+ z3
, FIX(0.670361295)); /* c5-c9 */
1521 tmp13
= tmp14
+ MULTIPLY(z1
+ z4
, FIX(0.366151574)); /* c7-c9 */
1522 tmp10
= tmp11
+ tmp12
+ tmp13
-
1523 MULTIPLY(z1
, FIX(0.923107866)); /* c7+c5+c3-c1-2*c9 */
1524 z1
= tmp14
- MULTIPLY(z2
+ z3
, FIX(1.163011579)); /* c7+c9 */
1525 tmp11
+= z1
+ MULTIPLY(z2
, FIX(2.073276588)); /* c1+c7+3*c9-c3 */
1526 tmp12
+= z1
- MULTIPLY(z3
, FIX(1.192193623)); /* c3+c5-c7-c9 */
1527 z1
= MULTIPLY(z2
+ z4
, - FIX(1.798248910)); /* -(c1+c9) */
1529 tmp13
+= z1
+ MULTIPLY(z4
, FIX(2.102458632)); /* c1+c5+c9-c7 */
1530 tmp14
+= MULTIPLY(z2
, - FIX(1.467221301)) + /* -(c5+c9) */
1531 MULTIPLY(z3
, FIX(1.001388905)) - /* c1-c9 */
1532 MULTIPLY(z4
, FIX(1.684843907)); /* c3+c9 */
1534 /* Final output stage */
1536 wsptr
[8*0] = (int) RIGHT_SHIFT(tmp20
+ tmp10
, CONST_BITS
-PASS1_BITS
);
1537 wsptr
[8*10] = (int) RIGHT_SHIFT(tmp20
- tmp10
, CONST_BITS
-PASS1_BITS
);
1538 wsptr
[8*1] = (int) RIGHT_SHIFT(tmp21
+ tmp11
, CONST_BITS
-PASS1_BITS
);
1539 wsptr
[8*9] = (int) RIGHT_SHIFT(tmp21
- tmp11
, CONST_BITS
-PASS1_BITS
);
1540 wsptr
[8*2] = (int) RIGHT_SHIFT(tmp22
+ tmp12
, CONST_BITS
-PASS1_BITS
);
1541 wsptr
[8*8] = (int) RIGHT_SHIFT(tmp22
- tmp12
, CONST_BITS
-PASS1_BITS
);
1542 wsptr
[8*3] = (int) RIGHT_SHIFT(tmp23
+ tmp13
, CONST_BITS
-PASS1_BITS
);
1543 wsptr
[8*7] = (int) RIGHT_SHIFT(tmp23
- tmp13
, CONST_BITS
-PASS1_BITS
);
1544 wsptr
[8*4] = (int) RIGHT_SHIFT(tmp24
+ tmp14
, CONST_BITS
-PASS1_BITS
);
1545 wsptr
[8*6] = (int) RIGHT_SHIFT(tmp24
- tmp14
, CONST_BITS
-PASS1_BITS
);
1546 wsptr
[8*5] = (int) RIGHT_SHIFT(tmp25
, CONST_BITS
-PASS1_BITS
);
1549 /* Pass 2: process 11 rows from work array, store into output array. */
1552 for (ctr
= 0; ctr
< 11; ctr
++) {
1553 outptr
= output_buf
[ctr
] + output_col
;
1557 /* Add fudge factor here for final descale. */
1558 tmp10
= (INT32
) wsptr
[0] + (ONE
<< (PASS1_BITS
+2));
1559 tmp10
<<= CONST_BITS
;
1561 z1
= (INT32
) wsptr
[2];
1562 z2
= (INT32
) wsptr
[4];
1563 z3
= (INT32
) wsptr
[6];
1565 tmp20
= MULTIPLY(z2
- z3
, FIX(2.546640132)); /* c2+c4 */
1566 tmp23
= MULTIPLY(z2
- z1
, FIX(0.430815045)); /* c2-c6 */
1568 tmp24
= MULTIPLY(z4
, - FIX(1.155664402)); /* -(c2-c10) */
1570 tmp25
= tmp10
+ MULTIPLY(z4
, FIX(1.356927976)); /* c2 */
1571 tmp21
= tmp20
+ tmp23
+ tmp25
-
1572 MULTIPLY(z2
, FIX(1.821790775)); /* c2+c4+c10-c6 */
1573 tmp20
+= tmp25
+ MULTIPLY(z3
, FIX(2.115825087)); /* c4+c6 */
1574 tmp23
+= tmp25
- MULTIPLY(z1
, FIX(1.513598477)); /* c6+c8 */
1576 tmp22
= tmp24
- MULTIPLY(z3
, FIX(0.788749120)); /* c8+c10 */
1577 tmp24
+= MULTIPLY(z2
, FIX(1.944413522)) - /* c2+c8 */
1578 MULTIPLY(z1
, FIX(1.390975730)); /* c4+c10 */
1579 tmp25
= tmp10
- MULTIPLY(z4
, FIX(1.414213562)); /* c0 */
1583 z1
= (INT32
) wsptr
[1];
1584 z2
= (INT32
) wsptr
[3];
1585 z3
= (INT32
) wsptr
[5];
1586 z4
= (INT32
) wsptr
[7];
1589 tmp14
= MULTIPLY(tmp11
+ z3
+ z4
, FIX(0.398430003)); /* c9 */
1590 tmp11
= MULTIPLY(tmp11
, FIX(0.887983902)); /* c3-c9 */
1591 tmp12
= MULTIPLY(z1
+ z3
, FIX(0.670361295)); /* c5-c9 */
1592 tmp13
= tmp14
+ MULTIPLY(z1
+ z4
, FIX(0.366151574)); /* c7-c9 */
1593 tmp10
= tmp11
+ tmp12
+ tmp13
-
1594 MULTIPLY(z1
, FIX(0.923107866)); /* c7+c5+c3-c1-2*c9 */
1595 z1
= tmp14
- MULTIPLY(z2
+ z3
, FIX(1.163011579)); /* c7+c9 */
1596 tmp11
+= z1
+ MULTIPLY(z2
, FIX(2.073276588)); /* c1+c7+3*c9-c3 */
1597 tmp12
+= z1
- MULTIPLY(z3
, FIX(1.192193623)); /* c3+c5-c7-c9 */
1598 z1
= MULTIPLY(z2
+ z4
, - FIX(1.798248910)); /* -(c1+c9) */
1600 tmp13
+= z1
+ MULTIPLY(z4
, FIX(2.102458632)); /* c1+c5+c9-c7 */
1601 tmp14
+= MULTIPLY(z2
, - FIX(1.467221301)) + /* -(c5+c9) */
1602 MULTIPLY(z3
, FIX(1.001388905)) - /* c1-c9 */
1603 MULTIPLY(z4
, FIX(1.684843907)); /* c3+c9 */
1605 /* Final output stage */
1607 outptr
[0] = range_limit
[(int) RIGHT_SHIFT(tmp20
+ tmp10
,
1608 CONST_BITS
+PASS1_BITS
+3)
1610 outptr
[10] = range_limit
[(int) RIGHT_SHIFT(tmp20
- tmp10
,
1611 CONST_BITS
+PASS1_BITS
+3)
1613 outptr
[1] = range_limit
[(int) RIGHT_SHIFT(tmp21
+ tmp11
,
1614 CONST_BITS
+PASS1_BITS
+3)
1616 outptr
[9] = range_limit
[(int) RIGHT_SHIFT(tmp21
- tmp11
,
1617 CONST_BITS
+PASS1_BITS
+3)
1619 outptr
[2] = range_limit
[(int) RIGHT_SHIFT(tmp22
+ tmp12
,
1620 CONST_BITS
+PASS1_BITS
+3)
1622 outptr
[8] = range_limit
[(int) RIGHT_SHIFT(tmp22
- tmp12
,
1623 CONST_BITS
+PASS1_BITS
+3)
1625 outptr
[3] = range_limit
[(int) RIGHT_SHIFT(tmp23
+ tmp13
,
1626 CONST_BITS
+PASS1_BITS
+3)
1628 outptr
[7] = range_limit
[(int) RIGHT_SHIFT(tmp23
- tmp13
,
1629 CONST_BITS
+PASS1_BITS
+3)
1631 outptr
[4] = range_limit
[(int) RIGHT_SHIFT(tmp24
+ tmp14
,
1632 CONST_BITS
+PASS1_BITS
+3)
1634 outptr
[6] = range_limit
[(int) RIGHT_SHIFT(tmp24
- tmp14
,
1635 CONST_BITS
+PASS1_BITS
+3)
1637 outptr
[5] = range_limit
[(int) RIGHT_SHIFT(tmp25
,
1638 CONST_BITS
+PASS1_BITS
+3)
1641 wsptr
+= 8; /* advance pointer to next row */
1647 * Perform dequantization and inverse DCT on one block of coefficients,
1648 * producing a 12x12 output block.
1650 * Optimized algorithm with 15 multiplications in the 1-D kernel.
1651 * cK represents sqrt(2) * cos(K*pi/24).
1655 jpeg_idct_12x12 (j_decompress_ptr cinfo
, jpeg_component_info
* compptr
,
1656 JCOEFPTR coef_block
,
1657 JSAMPARRAY output_buf
, JDIMENSION output_col
)
1659 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
, tmp15
;
1660 INT32 tmp20
, tmp21
, tmp22
, tmp23
, tmp24
, tmp25
;
1661 INT32 z1
, z2
, z3
, z4
;
1663 ISLOW_MULT_TYPE
* quantptr
;
1666 JSAMPLE
*range_limit
= IDCT_range_limit(cinfo
);
1668 int workspace
[8*12]; /* buffers data between passes */
1671 /* Pass 1: process columns from input, store into work array. */
1674 quantptr
= (ISLOW_MULT_TYPE
*) compptr
->dct_table
;
1676 for (ctr
= 0; ctr
< 8; ctr
++, inptr
++, quantptr
++, wsptr
++) {
1679 z3
= DEQUANTIZE(inptr
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]);
1681 /* Add fudge factor here for final descale. */
1682 z3
+= ONE
<< (CONST_BITS
-PASS1_BITS
-1);
1684 z4
= DEQUANTIZE(inptr
[DCTSIZE
*4], quantptr
[DCTSIZE
*4]);
1685 z4
= MULTIPLY(z4
, FIX(1.224744871)); /* c4 */
1690 z1
= DEQUANTIZE(inptr
[DCTSIZE
*2], quantptr
[DCTSIZE
*2]);
1691 z4
= MULTIPLY(z1
, FIX(1.366025404)); /* c2 */
1693 z2
= DEQUANTIZE(inptr
[DCTSIZE
*6], quantptr
[DCTSIZE
*6]);
1703 tmp20
= tmp10
+ tmp12
;
1704 tmp25
= tmp10
- tmp12
;
1706 tmp12
= z4
- z1
- z2
;
1708 tmp22
= tmp11
+ tmp12
;
1709 tmp23
= tmp11
- tmp12
;
1713 z1
= DEQUANTIZE(inptr
[DCTSIZE
*1], quantptr
[DCTSIZE
*1]);
1714 z2
= DEQUANTIZE(inptr
[DCTSIZE
*3], quantptr
[DCTSIZE
*3]);
1715 z3
= DEQUANTIZE(inptr
[DCTSIZE
*5], quantptr
[DCTSIZE
*5]);
1716 z4
= DEQUANTIZE(inptr
[DCTSIZE
*7], quantptr
[DCTSIZE
*7]);
1718 tmp11
= MULTIPLY(z2
, FIX(1.306562965)); /* c3 */
1719 tmp14
= MULTIPLY(z2
, - FIX_0_541196100
); /* -c9 */
1722 tmp15
= MULTIPLY(tmp10
+ z4
, FIX(0.860918669)); /* c7 */
1723 tmp12
= tmp15
+ MULTIPLY(tmp10
, FIX(0.261052384)); /* c5-c7 */
1724 tmp10
= tmp12
+ tmp11
+ MULTIPLY(z1
, FIX(0.280143716)); /* c1-c5 */
1725 tmp13
= MULTIPLY(z3
+ z4
, - FIX(1.045510580)); /* -(c7+c11) */
1726 tmp12
+= tmp13
+ tmp14
- MULTIPLY(z3
, FIX(1.478575242)); /* c1+c5-c7-c11 */
1727 tmp13
+= tmp15
- tmp11
+ MULTIPLY(z4
, FIX(1.586706681)); /* c1+c11 */
1728 tmp15
+= tmp14
- MULTIPLY(z1
, FIX(0.676326758)) - /* c7-c11 */
1729 MULTIPLY(z4
, FIX(1.982889723)); /* c5+c7 */
1733 z3
= MULTIPLY(z1
+ z2
, FIX_0_541196100
); /* c9 */
1734 tmp11
= z3
+ MULTIPLY(z1
, FIX_0_765366865
); /* c3-c9 */
1735 tmp14
= z3
- MULTIPLY(z2
, FIX_1_847759065
); /* c3+c9 */
1737 /* Final output stage */
1739 wsptr
[8*0] = (int) RIGHT_SHIFT(tmp20
+ tmp10
, CONST_BITS
-PASS1_BITS
);
1740 wsptr
[8*11] = (int) RIGHT_SHIFT(tmp20
- tmp10
, CONST_BITS
-PASS1_BITS
);
1741 wsptr
[8*1] = (int) RIGHT_SHIFT(tmp21
+ tmp11
, CONST_BITS
-PASS1_BITS
);
1742 wsptr
[8*10] = (int) RIGHT_SHIFT(tmp21
- tmp11
, CONST_BITS
-PASS1_BITS
);
1743 wsptr
[8*2] = (int) RIGHT_SHIFT(tmp22
+ tmp12
, CONST_BITS
-PASS1_BITS
);
1744 wsptr
[8*9] = (int) RIGHT_SHIFT(tmp22
- tmp12
, CONST_BITS
-PASS1_BITS
);
1745 wsptr
[8*3] = (int) RIGHT_SHIFT(tmp23
+ tmp13
, CONST_BITS
-PASS1_BITS
);
1746 wsptr
[8*8] = (int) RIGHT_SHIFT(tmp23
- tmp13
, CONST_BITS
-PASS1_BITS
);
1747 wsptr
[8*4] = (int) RIGHT_SHIFT(tmp24
+ tmp14
, CONST_BITS
-PASS1_BITS
);
1748 wsptr
[8*7] = (int) RIGHT_SHIFT(tmp24
- tmp14
, CONST_BITS
-PASS1_BITS
);
1749 wsptr
[8*5] = (int) RIGHT_SHIFT(tmp25
+ tmp15
, CONST_BITS
-PASS1_BITS
);
1750 wsptr
[8*6] = (int) RIGHT_SHIFT(tmp25
- tmp15
, CONST_BITS
-PASS1_BITS
);
1753 /* Pass 2: process 12 rows from work array, store into output array. */
1756 for (ctr
= 0; ctr
< 12; ctr
++) {
1757 outptr
= output_buf
[ctr
] + output_col
;
1761 /* Add fudge factor here for final descale. */
1762 z3
= (INT32
) wsptr
[0] + (ONE
<< (PASS1_BITS
+2));
1765 z4
= (INT32
) wsptr
[4];
1766 z4
= MULTIPLY(z4
, FIX(1.224744871)); /* c4 */
1771 z1
= (INT32
) wsptr
[2];
1772 z4
= MULTIPLY(z1
, FIX(1.366025404)); /* c2 */
1774 z2
= (INT32
) wsptr
[6];
1784 tmp20
= tmp10
+ tmp12
;
1785 tmp25
= tmp10
- tmp12
;
1787 tmp12
= z4
- z1
- z2
;
1789 tmp22
= tmp11
+ tmp12
;
1790 tmp23
= tmp11
- tmp12
;
1794 z1
= (INT32
) wsptr
[1];
1795 z2
= (INT32
) wsptr
[3];
1796 z3
= (INT32
) wsptr
[5];
1797 z4
= (INT32
) wsptr
[7];
1799 tmp11
= MULTIPLY(z2
, FIX(1.306562965)); /* c3 */
1800 tmp14
= MULTIPLY(z2
, - FIX_0_541196100
); /* -c9 */
1803 tmp15
= MULTIPLY(tmp10
+ z4
, FIX(0.860918669)); /* c7 */
1804 tmp12
= tmp15
+ MULTIPLY(tmp10
, FIX(0.261052384)); /* c5-c7 */
1805 tmp10
= tmp12
+ tmp11
+ MULTIPLY(z1
, FIX(0.280143716)); /* c1-c5 */
1806 tmp13
= MULTIPLY(z3
+ z4
, - FIX(1.045510580)); /* -(c7+c11) */
1807 tmp12
+= tmp13
+ tmp14
- MULTIPLY(z3
, FIX(1.478575242)); /* c1+c5-c7-c11 */
1808 tmp13
+= tmp15
- tmp11
+ MULTIPLY(z4
, FIX(1.586706681)); /* c1+c11 */
1809 tmp15
+= tmp14
- MULTIPLY(z1
, FIX(0.676326758)) - /* c7-c11 */
1810 MULTIPLY(z4
, FIX(1.982889723)); /* c5+c7 */
1814 z3
= MULTIPLY(z1
+ z2
, FIX_0_541196100
); /* c9 */
1815 tmp11
= z3
+ MULTIPLY(z1
, FIX_0_765366865
); /* c3-c9 */
1816 tmp14
= z3
- MULTIPLY(z2
, FIX_1_847759065
); /* c3+c9 */
1818 /* Final output stage */
1820 outptr
[0] = range_limit
[(int) RIGHT_SHIFT(tmp20
+ tmp10
,
1821 CONST_BITS
+PASS1_BITS
+3)
1823 outptr
[11] = range_limit
[(int) RIGHT_SHIFT(tmp20
- tmp10
,
1824 CONST_BITS
+PASS1_BITS
+3)
1826 outptr
[1] = range_limit
[(int) RIGHT_SHIFT(tmp21
+ tmp11
,
1827 CONST_BITS
+PASS1_BITS
+3)
1829 outptr
[10] = range_limit
[(int) RIGHT_SHIFT(tmp21
- tmp11
,
1830 CONST_BITS
+PASS1_BITS
+3)
1832 outptr
[2] = range_limit
[(int) RIGHT_SHIFT(tmp22
+ tmp12
,
1833 CONST_BITS
+PASS1_BITS
+3)
1835 outptr
[9] = range_limit
[(int) RIGHT_SHIFT(tmp22
- tmp12
,
1836 CONST_BITS
+PASS1_BITS
+3)
1838 outptr
[3] = range_limit
[(int) RIGHT_SHIFT(tmp23
+ tmp13
,
1839 CONST_BITS
+PASS1_BITS
+3)
1841 outptr
[8] = range_limit
[(int) RIGHT_SHIFT(tmp23
- tmp13
,
1842 CONST_BITS
+PASS1_BITS
+3)
1844 outptr
[4] = range_limit
[(int) RIGHT_SHIFT(tmp24
+ tmp14
,
1845 CONST_BITS
+PASS1_BITS
+3)
1847 outptr
[7] = range_limit
[(int) RIGHT_SHIFT(tmp24
- tmp14
,
1848 CONST_BITS
+PASS1_BITS
+3)
1850 outptr
[5] = range_limit
[(int) RIGHT_SHIFT(tmp25
+ tmp15
,
1851 CONST_BITS
+PASS1_BITS
+3)
1853 outptr
[6] = range_limit
[(int) RIGHT_SHIFT(tmp25
- tmp15
,
1854 CONST_BITS
+PASS1_BITS
+3)
1857 wsptr
+= 8; /* advance pointer to next row */
1863 * Perform dequantization and inverse DCT on one block of coefficients,
1864 * producing a 13x13 output block.
1866 * Optimized algorithm with 29 multiplications in the 1-D kernel.
1867 * cK represents sqrt(2) * cos(K*pi/26).
1871 jpeg_idct_13x13 (j_decompress_ptr cinfo
, jpeg_component_info
* compptr
,
1872 JCOEFPTR coef_block
,
1873 JSAMPARRAY output_buf
, JDIMENSION output_col
)
1875 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
, tmp15
;
1876 INT32 tmp20
, tmp21
, tmp22
, tmp23
, tmp24
, tmp25
, tmp26
;
1877 INT32 z1
, z2
, z3
, z4
;
1879 ISLOW_MULT_TYPE
* quantptr
;
1882 JSAMPLE
*range_limit
= IDCT_range_limit(cinfo
);
1884 int workspace
[8*13]; /* buffers data between passes */
1887 /* Pass 1: process columns from input, store into work array. */
1890 quantptr
= (ISLOW_MULT_TYPE
*) compptr
->dct_table
;
1892 for (ctr
= 0; ctr
< 8; ctr
++, inptr
++, quantptr
++, wsptr
++) {
1895 z1
= DEQUANTIZE(inptr
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]);
1897 /* Add fudge factor here for final descale. */
1898 z1
+= ONE
<< (CONST_BITS
-PASS1_BITS
-1);
1900 z2
= DEQUANTIZE(inptr
[DCTSIZE
*2], quantptr
[DCTSIZE
*2]);
1901 z3
= DEQUANTIZE(inptr
[DCTSIZE
*4], quantptr
[DCTSIZE
*4]);
1902 z4
= DEQUANTIZE(inptr
[DCTSIZE
*6], quantptr
[DCTSIZE
*6]);
1907 tmp12
= MULTIPLY(tmp10
, FIX(1.155388986)); /* (c4+c6)/2 */
1908 tmp13
= MULTIPLY(tmp11
, FIX(0.096834934)) + z1
; /* (c4-c6)/2 */
1910 tmp20
= MULTIPLY(z2
, FIX(1.373119086)) + tmp12
+ tmp13
; /* c2 */
1911 tmp22
= MULTIPLY(z2
, FIX(0.501487041)) - tmp12
+ tmp13
; /* c10 */
1913 tmp12
= MULTIPLY(tmp10
, FIX(0.316450131)); /* (c8-c12)/2 */
1914 tmp13
= MULTIPLY(tmp11
, FIX(0.486914739)) + z1
; /* (c8+c12)/2 */
1916 tmp21
= MULTIPLY(z2
, FIX(1.058554052)) - tmp12
+ tmp13
; /* c6 */
1917 tmp25
= MULTIPLY(z2
, - FIX(1.252223920)) + tmp12
+ tmp13
; /* c4 */
1919 tmp12
= MULTIPLY(tmp10
, FIX(0.435816023)); /* (c2-c10)/2 */
1920 tmp13
= MULTIPLY(tmp11
, FIX(0.937303064)) - z1
; /* (c2+c10)/2 */
1922 tmp23
= MULTIPLY(z2
, - FIX(0.170464608)) - tmp12
- tmp13
; /* c12 */
1923 tmp24
= MULTIPLY(z2
, - FIX(0.803364869)) + tmp12
- tmp13
; /* c8 */
1925 tmp26
= MULTIPLY(tmp11
- z2
, FIX(1.414213562)) + z1
; /* c0 */
1929 z1
= DEQUANTIZE(inptr
[DCTSIZE
*1], quantptr
[DCTSIZE
*1]);
1930 z2
= DEQUANTIZE(inptr
[DCTSIZE
*3], quantptr
[DCTSIZE
*3]);
1931 z3
= DEQUANTIZE(inptr
[DCTSIZE
*5], quantptr
[DCTSIZE
*5]);
1932 z4
= DEQUANTIZE(inptr
[DCTSIZE
*7], quantptr
[DCTSIZE
*7]);
1934 tmp11
= MULTIPLY(z1
+ z2
, FIX(1.322312651)); /* c3 */
1935 tmp12
= MULTIPLY(z1
+ z3
, FIX(1.163874945)); /* c5 */
1937 tmp13
= MULTIPLY(tmp15
, FIX(0.937797057)); /* c7 */
1938 tmp10
= tmp11
+ tmp12
+ tmp13
-
1939 MULTIPLY(z1
, FIX(2.020082300)); /* c7+c5+c3-c1 */
1940 tmp14
= MULTIPLY(z2
+ z3
, - FIX(0.338443458)); /* -c11 */
1941 tmp11
+= tmp14
+ MULTIPLY(z2
, FIX(0.837223564)); /* c5+c9+c11-c3 */
1942 tmp12
+= tmp14
- MULTIPLY(z3
, FIX(1.572116027)); /* c1+c5-c9-c11 */
1943 tmp14
= MULTIPLY(z2
+ z4
, - FIX(1.163874945)); /* -c5 */
1945 tmp13
+= tmp14
+ MULTIPLY(z4
, FIX(2.205608352)); /* c3+c5+c9-c7 */
1946 tmp14
= MULTIPLY(z3
+ z4
, - FIX(0.657217813)); /* -c9 */
1949 tmp15
= MULTIPLY(tmp15
, FIX(0.338443458)); /* c11 */
1950 tmp14
= tmp15
+ MULTIPLY(z1
, FIX(0.318774355)) - /* c9-c11 */
1951 MULTIPLY(z2
, FIX(0.466105296)); /* c1-c7 */
1952 z1
= MULTIPLY(z3
- z2
, FIX(0.937797057)); /* c7 */
1954 tmp15
+= z1
+ MULTIPLY(z3
, FIX(0.384515595)) - /* c3-c7 */
1955 MULTIPLY(z4
, FIX(1.742345811)); /* c1+c11 */
1957 /* Final output stage */
1959 wsptr
[8*0] = (int) RIGHT_SHIFT(tmp20
+ tmp10
, CONST_BITS
-PASS1_BITS
);
1960 wsptr
[8*12] = (int) RIGHT_SHIFT(tmp20
- tmp10
, CONST_BITS
-PASS1_BITS
);
1961 wsptr
[8*1] = (int) RIGHT_SHIFT(tmp21
+ tmp11
, CONST_BITS
-PASS1_BITS
);
1962 wsptr
[8*11] = (int) RIGHT_SHIFT(tmp21
- tmp11
, CONST_BITS
-PASS1_BITS
);
1963 wsptr
[8*2] = (int) RIGHT_SHIFT(tmp22
+ tmp12
, CONST_BITS
-PASS1_BITS
);
1964 wsptr
[8*10] = (int) RIGHT_SHIFT(tmp22
- tmp12
, CONST_BITS
-PASS1_BITS
);
1965 wsptr
[8*3] = (int) RIGHT_SHIFT(tmp23
+ tmp13
, CONST_BITS
-PASS1_BITS
);
1966 wsptr
[8*9] = (int) RIGHT_SHIFT(tmp23
- tmp13
, CONST_BITS
-PASS1_BITS
);
1967 wsptr
[8*4] = (int) RIGHT_SHIFT(tmp24
+ tmp14
, CONST_BITS
-PASS1_BITS
);
1968 wsptr
[8*8] = (int) RIGHT_SHIFT(tmp24
- tmp14
, CONST_BITS
-PASS1_BITS
);
1969 wsptr
[8*5] = (int) RIGHT_SHIFT(tmp25
+ tmp15
, CONST_BITS
-PASS1_BITS
);
1970 wsptr
[8*7] = (int) RIGHT_SHIFT(tmp25
- tmp15
, CONST_BITS
-PASS1_BITS
);
1971 wsptr
[8*6] = (int) RIGHT_SHIFT(tmp26
, CONST_BITS
-PASS1_BITS
);
1974 /* Pass 2: process 13 rows from work array, store into output array. */
1977 for (ctr
= 0; ctr
< 13; ctr
++) {
1978 outptr
= output_buf
[ctr
] + output_col
;
1982 /* Add fudge factor here for final descale. */
1983 z1
= (INT32
) wsptr
[0] + (ONE
<< (PASS1_BITS
+2));
1986 z2
= (INT32
) wsptr
[2];
1987 z3
= (INT32
) wsptr
[4];
1988 z4
= (INT32
) wsptr
[6];
1993 tmp12
= MULTIPLY(tmp10
, FIX(1.155388986)); /* (c4+c6)/2 */
1994 tmp13
= MULTIPLY(tmp11
, FIX(0.096834934)) + z1
; /* (c4-c6)/2 */
1996 tmp20
= MULTIPLY(z2
, FIX(1.373119086)) + tmp12
+ tmp13
; /* c2 */
1997 tmp22
= MULTIPLY(z2
, FIX(0.501487041)) - tmp12
+ tmp13
; /* c10 */
1999 tmp12
= MULTIPLY(tmp10
, FIX(0.316450131)); /* (c8-c12)/2 */
2000 tmp13
= MULTIPLY(tmp11
, FIX(0.486914739)) + z1
; /* (c8+c12)/2 */
2002 tmp21
= MULTIPLY(z2
, FIX(1.058554052)) - tmp12
+ tmp13
; /* c6 */
2003 tmp25
= MULTIPLY(z2
, - FIX(1.252223920)) + tmp12
+ tmp13
; /* c4 */
2005 tmp12
= MULTIPLY(tmp10
, FIX(0.435816023)); /* (c2-c10)/2 */
2006 tmp13
= MULTIPLY(tmp11
, FIX(0.937303064)) - z1
; /* (c2+c10)/2 */
2008 tmp23
= MULTIPLY(z2
, - FIX(0.170464608)) - tmp12
- tmp13
; /* c12 */
2009 tmp24
= MULTIPLY(z2
, - FIX(0.803364869)) + tmp12
- tmp13
; /* c8 */
2011 tmp26
= MULTIPLY(tmp11
- z2
, FIX(1.414213562)) + z1
; /* c0 */
2015 z1
= (INT32
) wsptr
[1];
2016 z2
= (INT32
) wsptr
[3];
2017 z3
= (INT32
) wsptr
[5];
2018 z4
= (INT32
) wsptr
[7];
2020 tmp11
= MULTIPLY(z1
+ z2
, FIX(1.322312651)); /* c3 */
2021 tmp12
= MULTIPLY(z1
+ z3
, FIX(1.163874945)); /* c5 */
2023 tmp13
= MULTIPLY(tmp15
, FIX(0.937797057)); /* c7 */
2024 tmp10
= tmp11
+ tmp12
+ tmp13
-
2025 MULTIPLY(z1
, FIX(2.020082300)); /* c7+c5+c3-c1 */
2026 tmp14
= MULTIPLY(z2
+ z3
, - FIX(0.338443458)); /* -c11 */
2027 tmp11
+= tmp14
+ MULTIPLY(z2
, FIX(0.837223564)); /* c5+c9+c11-c3 */
2028 tmp12
+= tmp14
- MULTIPLY(z3
, FIX(1.572116027)); /* c1+c5-c9-c11 */
2029 tmp14
= MULTIPLY(z2
+ z4
, - FIX(1.163874945)); /* -c5 */
2031 tmp13
+= tmp14
+ MULTIPLY(z4
, FIX(2.205608352)); /* c3+c5+c9-c7 */
2032 tmp14
= MULTIPLY(z3
+ z4
, - FIX(0.657217813)); /* -c9 */
2035 tmp15
= MULTIPLY(tmp15
, FIX(0.338443458)); /* c11 */
2036 tmp14
= tmp15
+ MULTIPLY(z1
, FIX(0.318774355)) - /* c9-c11 */
2037 MULTIPLY(z2
, FIX(0.466105296)); /* c1-c7 */
2038 z1
= MULTIPLY(z3
- z2
, FIX(0.937797057)); /* c7 */
2040 tmp15
+= z1
+ MULTIPLY(z3
, FIX(0.384515595)) - /* c3-c7 */
2041 MULTIPLY(z4
, FIX(1.742345811)); /* c1+c11 */
2043 /* Final output stage */
2045 outptr
[0] = range_limit
[(int) RIGHT_SHIFT(tmp20
+ tmp10
,
2046 CONST_BITS
+PASS1_BITS
+3)
2048 outptr
[12] = range_limit
[(int) RIGHT_SHIFT(tmp20
- tmp10
,
2049 CONST_BITS
+PASS1_BITS
+3)
2051 outptr
[1] = range_limit
[(int) RIGHT_SHIFT(tmp21
+ tmp11
,
2052 CONST_BITS
+PASS1_BITS
+3)
2054 outptr
[11] = range_limit
[(int) RIGHT_SHIFT(tmp21
- tmp11
,
2055 CONST_BITS
+PASS1_BITS
+3)
2057 outptr
[2] = range_limit
[(int) RIGHT_SHIFT(tmp22
+ tmp12
,
2058 CONST_BITS
+PASS1_BITS
+3)
2060 outptr
[10] = range_limit
[(int) RIGHT_SHIFT(tmp22
- tmp12
,
2061 CONST_BITS
+PASS1_BITS
+3)
2063 outptr
[3] = range_limit
[(int) RIGHT_SHIFT(tmp23
+ tmp13
,
2064 CONST_BITS
+PASS1_BITS
+3)
2066 outptr
[9] = range_limit
[(int) RIGHT_SHIFT(tmp23
- tmp13
,
2067 CONST_BITS
+PASS1_BITS
+3)
2069 outptr
[4] = range_limit
[(int) RIGHT_SHIFT(tmp24
+ tmp14
,
2070 CONST_BITS
+PASS1_BITS
+3)
2072 outptr
[8] = range_limit
[(int) RIGHT_SHIFT(tmp24
- tmp14
,
2073 CONST_BITS
+PASS1_BITS
+3)
2075 outptr
[5] = range_limit
[(int) RIGHT_SHIFT(tmp25
+ tmp15
,
2076 CONST_BITS
+PASS1_BITS
+3)
2078 outptr
[7] = range_limit
[(int) RIGHT_SHIFT(tmp25
- tmp15
,
2079 CONST_BITS
+PASS1_BITS
+3)
2081 outptr
[6] = range_limit
[(int) RIGHT_SHIFT(tmp26
,
2082 CONST_BITS
+PASS1_BITS
+3)
2085 wsptr
+= 8; /* advance pointer to next row */
2091 * Perform dequantization and inverse DCT on one block of coefficients,
2092 * producing a 14x14 output block.
2094 * Optimized algorithm with 20 multiplications in the 1-D kernel.
2095 * cK represents sqrt(2) * cos(K*pi/28).
2099 jpeg_idct_14x14 (j_decompress_ptr cinfo
, jpeg_component_info
* compptr
,
2100 JCOEFPTR coef_block
,
2101 JSAMPARRAY output_buf
, JDIMENSION output_col
)
2103 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
, tmp15
, tmp16
;
2104 INT32 tmp20
, tmp21
, tmp22
, tmp23
, tmp24
, tmp25
, tmp26
;
2105 INT32 z1
, z2
, z3
, z4
;
2107 ISLOW_MULT_TYPE
* quantptr
;
2110 JSAMPLE
*range_limit
= IDCT_range_limit(cinfo
);
2112 int workspace
[8*14]; /* buffers data between passes */
2115 /* Pass 1: process columns from input, store into work array. */
2118 quantptr
= (ISLOW_MULT_TYPE
*) compptr
->dct_table
;
2120 for (ctr
= 0; ctr
< 8; ctr
++, inptr
++, quantptr
++, wsptr
++) {
2123 z1
= DEQUANTIZE(inptr
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]);
2125 /* Add fudge factor here for final descale. */
2126 z1
+= ONE
<< (CONST_BITS
-PASS1_BITS
-1);
2127 z4
= DEQUANTIZE(inptr
[DCTSIZE
*4], quantptr
[DCTSIZE
*4]);
2128 z2
= MULTIPLY(z4
, FIX(1.274162392)); /* c4 */
2129 z3
= MULTIPLY(z4
, FIX(0.314692123)); /* c12 */
2130 z4
= MULTIPLY(z4
, FIX(0.881747734)); /* c8 */
2136 tmp23
= RIGHT_SHIFT(z1
- ((z2
+ z3
- z4
) << 1), /* c0 = (c4+c12-c8)*2 */
2137 CONST_BITS
-PASS1_BITS
);
2139 z1
= DEQUANTIZE(inptr
[DCTSIZE
*2], quantptr
[DCTSIZE
*2]);
2140 z2
= DEQUANTIZE(inptr
[DCTSIZE
*6], quantptr
[DCTSIZE
*6]);
2142 z3
= MULTIPLY(z1
+ z2
, FIX(1.105676686)); /* c6 */
2144 tmp13
= z3
+ MULTIPLY(z1
, FIX(0.273079590)); /* c2-c6 */
2145 tmp14
= z3
- MULTIPLY(z2
, FIX(1.719280954)); /* c6+c10 */
2146 tmp15
= MULTIPLY(z1
, FIX(0.613604268)) - /* c10 */
2147 MULTIPLY(z2
, FIX(1.378756276)); /* c2 */
2149 tmp20
= tmp10
+ tmp13
;
2150 tmp26
= tmp10
- tmp13
;
2151 tmp21
= tmp11
+ tmp14
;
2152 tmp25
= tmp11
- tmp14
;
2153 tmp22
= tmp12
+ tmp15
;
2154 tmp24
= tmp12
- tmp15
;
2158 z1
= DEQUANTIZE(inptr
[DCTSIZE
*1], quantptr
[DCTSIZE
*1]);
2159 z2
= DEQUANTIZE(inptr
[DCTSIZE
*3], quantptr
[DCTSIZE
*3]);
2160 z3
= DEQUANTIZE(inptr
[DCTSIZE
*5], quantptr
[DCTSIZE
*5]);
2161 z4
= DEQUANTIZE(inptr
[DCTSIZE
*7], quantptr
[DCTSIZE
*7]);
2162 tmp13
= z4
<< CONST_BITS
;
2165 tmp11
= MULTIPLY(z1
+ z2
, FIX(1.334852607)); /* c3 */
2166 tmp12
= MULTIPLY(tmp14
, FIX(1.197448846)); /* c5 */
2167 tmp10
= tmp11
+ tmp12
+ tmp13
- MULTIPLY(z1
, FIX(1.126980169)); /* c3+c5-c1 */
2168 tmp14
= MULTIPLY(tmp14
, FIX(0.752406978)); /* c9 */
2169 tmp16
= tmp14
- MULTIPLY(z1
, FIX(1.061150426)); /* c9+c11-c13 */
2171 tmp15
= MULTIPLY(z1
, FIX(0.467085129)) - tmp13
; /* c11 */
2174 z4
= MULTIPLY(z2
+ z3
, - FIX(0.158341681)) - tmp13
; /* -c13 */
2175 tmp11
+= z4
- MULTIPLY(z2
, FIX(0.424103948)); /* c3-c9-c13 */
2176 tmp12
+= z4
- MULTIPLY(z3
, FIX(2.373959773)); /* c3+c5-c13 */
2177 z4
= MULTIPLY(z3
- z2
, FIX(1.405321284)); /* c1 */
2178 tmp14
+= z4
+ tmp13
- MULTIPLY(z3
, FIX(1.6906431334)); /* c1+c9-c11 */
2179 tmp15
+= z4
+ MULTIPLY(z2
, FIX(0.674957567)); /* c1+c11-c5 */
2181 tmp13
= (z1
- z3
) << PASS1_BITS
;
2183 /* Final output stage */
2185 wsptr
[8*0] = (int) RIGHT_SHIFT(tmp20
+ tmp10
, CONST_BITS
-PASS1_BITS
);
2186 wsptr
[8*13] = (int) RIGHT_SHIFT(tmp20
- tmp10
, CONST_BITS
-PASS1_BITS
);
2187 wsptr
[8*1] = (int) RIGHT_SHIFT(tmp21
+ tmp11
, CONST_BITS
-PASS1_BITS
);
2188 wsptr
[8*12] = (int) RIGHT_SHIFT(tmp21
- tmp11
, CONST_BITS
-PASS1_BITS
);
2189 wsptr
[8*2] = (int) RIGHT_SHIFT(tmp22
+ tmp12
, CONST_BITS
-PASS1_BITS
);
2190 wsptr
[8*11] = (int) RIGHT_SHIFT(tmp22
- tmp12
, CONST_BITS
-PASS1_BITS
);
2191 wsptr
[8*3] = (int) (tmp23
+ tmp13
);
2192 wsptr
[8*10] = (int) (tmp23
- tmp13
);
2193 wsptr
[8*4] = (int) RIGHT_SHIFT(tmp24
+ tmp14
, CONST_BITS
-PASS1_BITS
);
2194 wsptr
[8*9] = (int) RIGHT_SHIFT(tmp24
- tmp14
, CONST_BITS
-PASS1_BITS
);
2195 wsptr
[8*5] = (int) RIGHT_SHIFT(tmp25
+ tmp15
, CONST_BITS
-PASS1_BITS
);
2196 wsptr
[8*8] = (int) RIGHT_SHIFT(tmp25
- tmp15
, CONST_BITS
-PASS1_BITS
);
2197 wsptr
[8*6] = (int) RIGHT_SHIFT(tmp26
+ tmp16
, CONST_BITS
-PASS1_BITS
);
2198 wsptr
[8*7] = (int) RIGHT_SHIFT(tmp26
- tmp16
, CONST_BITS
-PASS1_BITS
);
2201 /* Pass 2: process 14 rows from work array, store into output array. */
2204 for (ctr
= 0; ctr
< 14; ctr
++) {
2205 outptr
= output_buf
[ctr
] + output_col
;
2209 /* Add fudge factor here for final descale. */
2210 z1
= (INT32
) wsptr
[0] + (ONE
<< (PASS1_BITS
+2));
2212 z4
= (INT32
) wsptr
[4];
2213 z2
= MULTIPLY(z4
, FIX(1.274162392)); /* c4 */
2214 z3
= MULTIPLY(z4
, FIX(0.314692123)); /* c12 */
2215 z4
= MULTIPLY(z4
, FIX(0.881747734)); /* c8 */
2221 tmp23
= z1
- ((z2
+ z3
- z4
) << 1); /* c0 = (c4+c12-c8)*2 */
2223 z1
= (INT32
) wsptr
[2];
2224 z2
= (INT32
) wsptr
[6];
2226 z3
= MULTIPLY(z1
+ z2
, FIX(1.105676686)); /* c6 */
2228 tmp13
= z3
+ MULTIPLY(z1
, FIX(0.273079590)); /* c2-c6 */
2229 tmp14
= z3
- MULTIPLY(z2
, FIX(1.719280954)); /* c6+c10 */
2230 tmp15
= MULTIPLY(z1
, FIX(0.613604268)) - /* c10 */
2231 MULTIPLY(z2
, FIX(1.378756276)); /* c2 */
2233 tmp20
= tmp10
+ tmp13
;
2234 tmp26
= tmp10
- tmp13
;
2235 tmp21
= tmp11
+ tmp14
;
2236 tmp25
= tmp11
- tmp14
;
2237 tmp22
= tmp12
+ tmp15
;
2238 tmp24
= tmp12
- tmp15
;
2242 z1
= (INT32
) wsptr
[1];
2243 z2
= (INT32
) wsptr
[3];
2244 z3
= (INT32
) wsptr
[5];
2245 z4
= (INT32
) wsptr
[7];
2249 tmp11
= MULTIPLY(z1
+ z2
, FIX(1.334852607)); /* c3 */
2250 tmp12
= MULTIPLY(tmp14
, FIX(1.197448846)); /* c5 */
2251 tmp10
= tmp11
+ tmp12
+ z4
- MULTIPLY(z1
, FIX(1.126980169)); /* c3+c5-c1 */
2252 tmp14
= MULTIPLY(tmp14
, FIX(0.752406978)); /* c9 */
2253 tmp16
= tmp14
- MULTIPLY(z1
, FIX(1.061150426)); /* c9+c11-c13 */
2255 tmp15
= MULTIPLY(z1
, FIX(0.467085129)) - z4
; /* c11 */
2257 tmp13
= MULTIPLY(z2
+ z3
, - FIX(0.158341681)) - z4
; /* -c13 */
2258 tmp11
+= tmp13
- MULTIPLY(z2
, FIX(0.424103948)); /* c3-c9-c13 */
2259 tmp12
+= tmp13
- MULTIPLY(z3
, FIX(2.373959773)); /* c3+c5-c13 */
2260 tmp13
= MULTIPLY(z3
- z2
, FIX(1.405321284)); /* c1 */
2261 tmp14
+= tmp13
+ z4
- MULTIPLY(z3
, FIX(1.6906431334)); /* c1+c9-c11 */
2262 tmp15
+= tmp13
+ MULTIPLY(z2
, FIX(0.674957567)); /* c1+c11-c5 */
2264 tmp13
= ((z1
- z3
) << CONST_BITS
) + z4
;
2266 /* Final output stage */
2268 outptr
[0] = range_limit
[(int) RIGHT_SHIFT(tmp20
+ tmp10
,
2269 CONST_BITS
+PASS1_BITS
+3)
2271 outptr
[13] = range_limit
[(int) RIGHT_SHIFT(tmp20
- tmp10
,
2272 CONST_BITS
+PASS1_BITS
+3)
2274 outptr
[1] = range_limit
[(int) RIGHT_SHIFT(tmp21
+ tmp11
,
2275 CONST_BITS
+PASS1_BITS
+3)
2277 outptr
[12] = range_limit
[(int) RIGHT_SHIFT(tmp21
- tmp11
,
2278 CONST_BITS
+PASS1_BITS
+3)
2280 outptr
[2] = range_limit
[(int) RIGHT_SHIFT(tmp22
+ tmp12
,
2281 CONST_BITS
+PASS1_BITS
+3)
2283 outptr
[11] = range_limit
[(int) RIGHT_SHIFT(tmp22
- tmp12
,
2284 CONST_BITS
+PASS1_BITS
+3)
2286 outptr
[3] = range_limit
[(int) RIGHT_SHIFT(tmp23
+ tmp13
,
2287 CONST_BITS
+PASS1_BITS
+3)
2289 outptr
[10] = range_limit
[(int) RIGHT_SHIFT(tmp23
- tmp13
,
2290 CONST_BITS
+PASS1_BITS
+3)
2292 outptr
[4] = range_limit
[(int) RIGHT_SHIFT(tmp24
+ tmp14
,
2293 CONST_BITS
+PASS1_BITS
+3)
2295 outptr
[9] = range_limit
[(int) RIGHT_SHIFT(tmp24
- tmp14
,
2296 CONST_BITS
+PASS1_BITS
+3)
2298 outptr
[5] = range_limit
[(int) RIGHT_SHIFT(tmp25
+ tmp15
,
2299 CONST_BITS
+PASS1_BITS
+3)
2301 outptr
[8] = range_limit
[(int) RIGHT_SHIFT(tmp25
- tmp15
,
2302 CONST_BITS
+PASS1_BITS
+3)
2304 outptr
[6] = range_limit
[(int) RIGHT_SHIFT(tmp26
+ tmp16
,
2305 CONST_BITS
+PASS1_BITS
+3)
2307 outptr
[7] = range_limit
[(int) RIGHT_SHIFT(tmp26
- tmp16
,
2308 CONST_BITS
+PASS1_BITS
+3)
2311 wsptr
+= 8; /* advance pointer to next row */
2317 * Perform dequantization and inverse DCT on one block of coefficients,
2318 * producing a 15x15 output block.
2320 * Optimized algorithm with 22 multiplications in the 1-D kernel.
2321 * cK represents sqrt(2) * cos(K*pi/30).
2325 jpeg_idct_15x15 (j_decompress_ptr cinfo
, jpeg_component_info
* compptr
,
2326 JCOEFPTR coef_block
,
2327 JSAMPARRAY output_buf
, JDIMENSION output_col
)
2329 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
, tmp15
, tmp16
;
2330 INT32 tmp20
, tmp21
, tmp22
, tmp23
, tmp24
, tmp25
, tmp26
, tmp27
;
2331 INT32 z1
, z2
, z3
, z4
;
2333 ISLOW_MULT_TYPE
* quantptr
;
2336 JSAMPLE
*range_limit
= IDCT_range_limit(cinfo
);
2338 int workspace
[8*15]; /* buffers data between passes */
2341 /* Pass 1: process columns from input, store into work array. */
2344 quantptr
= (ISLOW_MULT_TYPE
*) compptr
->dct_table
;
2346 for (ctr
= 0; ctr
< 8; ctr
++, inptr
++, quantptr
++, wsptr
++) {
2349 z1
= DEQUANTIZE(inptr
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]);
2351 /* Add fudge factor here for final descale. */
2352 z1
+= ONE
<< (CONST_BITS
-PASS1_BITS
-1);
2354 z2
= DEQUANTIZE(inptr
[DCTSIZE
*2], quantptr
[DCTSIZE
*2]);
2355 z3
= DEQUANTIZE(inptr
[DCTSIZE
*4], quantptr
[DCTSIZE
*4]);
2356 z4
= DEQUANTIZE(inptr
[DCTSIZE
*6], quantptr
[DCTSIZE
*6]);
2358 tmp10
= MULTIPLY(z4
, FIX(0.437016024)); /* c12 */
2359 tmp11
= MULTIPLY(z4
, FIX(1.144122806)); /* c6 */
2363 z1
-= (tmp11
- tmp10
) << 1; /* c0 = (c6-c12)*2 */
2367 tmp10
= MULTIPLY(z3
, FIX(1.337628990)); /* (c2+c4)/2 */
2368 tmp11
= MULTIPLY(z4
, FIX(0.045680613)); /* (c2-c4)/2 */
2369 z2
= MULTIPLY(z2
, FIX(1.439773946)); /* c4+c14 */
2371 tmp20
= tmp13
+ tmp10
+ tmp11
;
2372 tmp23
= tmp12
- tmp10
+ tmp11
+ z2
;
2374 tmp10
= MULTIPLY(z3
, FIX(0.547059574)); /* (c8+c14)/2 */
2375 tmp11
= MULTIPLY(z4
, FIX(0.399234004)); /* (c8-c14)/2 */
2377 tmp25
= tmp13
- tmp10
- tmp11
;
2378 tmp26
= tmp12
+ tmp10
- tmp11
- z2
;
2380 tmp10
= MULTIPLY(z3
, FIX(0.790569415)); /* (c6+c12)/2 */
2381 tmp11
= MULTIPLY(z4
, FIX(0.353553391)); /* (c6-c12)/2 */
2383 tmp21
= tmp12
+ tmp10
+ tmp11
;
2384 tmp24
= tmp13
- tmp10
+ tmp11
;
2386 tmp22
= z1
+ tmp11
; /* c10 = c6-c12 */
2387 tmp27
= z1
- tmp11
- tmp11
; /* c0 = (c6-c12)*2 */
2391 z1
= DEQUANTIZE(inptr
[DCTSIZE
*1], quantptr
[DCTSIZE
*1]);
2392 z2
= DEQUANTIZE(inptr
[DCTSIZE
*3], quantptr
[DCTSIZE
*3]);
2393 z4
= DEQUANTIZE(inptr
[DCTSIZE
*5], quantptr
[DCTSIZE
*5]);
2394 z3
= MULTIPLY(z4
, FIX(1.224744871)); /* c5 */
2395 z4
= DEQUANTIZE(inptr
[DCTSIZE
*7], quantptr
[DCTSIZE
*7]);
2398 tmp15
= MULTIPLY(z1
+ tmp13
, FIX(0.831253876)); /* c9 */
2399 tmp11
= tmp15
+ MULTIPLY(z1
, FIX(0.513743148)); /* c3-c9 */
2400 tmp14
= tmp15
- MULTIPLY(tmp13
, FIX(2.176250899)); /* c3+c9 */
2402 tmp13
= MULTIPLY(z2
, - FIX(0.831253876)); /* -c9 */
2403 tmp15
= MULTIPLY(z2
, - FIX(1.344997024)); /* -c3 */
2405 tmp12
= z3
+ MULTIPLY(z2
, FIX(1.406466353)); /* c1 */
2407 tmp10
= tmp12
+ MULTIPLY(z4
, FIX(2.457431844)) - tmp15
; /* c1+c7 */
2408 tmp16
= tmp12
- MULTIPLY(z1
, FIX(1.112434820)) + tmp13
; /* c1-c13 */
2409 tmp12
= MULTIPLY(z2
, FIX(1.224744871)) - z3
; /* c5 */
2410 z2
= MULTIPLY(z1
+ z4
, FIX(0.575212477)); /* c11 */
2411 tmp13
+= z2
+ MULTIPLY(z1
, FIX(0.475753014)) - z3
; /* c7-c11 */
2412 tmp15
+= z2
- MULTIPLY(z4
, FIX(0.869244010)) + z3
; /* c11+c13 */
2414 /* Final output stage */
2416 wsptr
[8*0] = (int) RIGHT_SHIFT(tmp20
+ tmp10
, CONST_BITS
-PASS1_BITS
);
2417 wsptr
[8*14] = (int) RIGHT_SHIFT(tmp20
- tmp10
, CONST_BITS
-PASS1_BITS
);
2418 wsptr
[8*1] = (int) RIGHT_SHIFT(tmp21
+ tmp11
, CONST_BITS
-PASS1_BITS
);
2419 wsptr
[8*13] = (int) RIGHT_SHIFT(tmp21
- tmp11
, CONST_BITS
-PASS1_BITS
);
2420 wsptr
[8*2] = (int) RIGHT_SHIFT(tmp22
+ tmp12
, CONST_BITS
-PASS1_BITS
);
2421 wsptr
[8*12] = (int) RIGHT_SHIFT(tmp22
- tmp12
, CONST_BITS
-PASS1_BITS
);
2422 wsptr
[8*3] = (int) RIGHT_SHIFT(tmp23
+ tmp13
, CONST_BITS
-PASS1_BITS
);
2423 wsptr
[8*11] = (int) RIGHT_SHIFT(tmp23
- tmp13
, CONST_BITS
-PASS1_BITS
);
2424 wsptr
[8*4] = (int) RIGHT_SHIFT(tmp24
+ tmp14
, CONST_BITS
-PASS1_BITS
);
2425 wsptr
[8*10] = (int) RIGHT_SHIFT(tmp24
- tmp14
, CONST_BITS
-PASS1_BITS
);
2426 wsptr
[8*5] = (int) RIGHT_SHIFT(tmp25
+ tmp15
, CONST_BITS
-PASS1_BITS
);
2427 wsptr
[8*9] = (int) RIGHT_SHIFT(tmp25
- tmp15
, CONST_BITS
-PASS1_BITS
);
2428 wsptr
[8*6] = (int) RIGHT_SHIFT(tmp26
+ tmp16
, CONST_BITS
-PASS1_BITS
);
2429 wsptr
[8*8] = (int) RIGHT_SHIFT(tmp26
- tmp16
, CONST_BITS
-PASS1_BITS
);
2430 wsptr
[8*7] = (int) RIGHT_SHIFT(tmp27
, CONST_BITS
-PASS1_BITS
);
2433 /* Pass 2: process 15 rows from work array, store into output array. */
2436 for (ctr
= 0; ctr
< 15; ctr
++) {
2437 outptr
= output_buf
[ctr
] + output_col
;
2441 /* Add fudge factor here for final descale. */
2442 z1
= (INT32
) wsptr
[0] + (ONE
<< (PASS1_BITS
+2));
2445 z2
= (INT32
) wsptr
[2];
2446 z3
= (INT32
) wsptr
[4];
2447 z4
= (INT32
) wsptr
[6];
2449 tmp10
= MULTIPLY(z4
, FIX(0.437016024)); /* c12 */
2450 tmp11
= MULTIPLY(z4
, FIX(1.144122806)); /* c6 */
2454 z1
-= (tmp11
- tmp10
) << 1; /* c0 = (c6-c12)*2 */
2458 tmp10
= MULTIPLY(z3
, FIX(1.337628990)); /* (c2+c4)/2 */
2459 tmp11
= MULTIPLY(z4
, FIX(0.045680613)); /* (c2-c4)/2 */
2460 z2
= MULTIPLY(z2
, FIX(1.439773946)); /* c4+c14 */
2462 tmp20
= tmp13
+ tmp10
+ tmp11
;
2463 tmp23
= tmp12
- tmp10
+ tmp11
+ z2
;
2465 tmp10
= MULTIPLY(z3
, FIX(0.547059574)); /* (c8+c14)/2 */
2466 tmp11
= MULTIPLY(z4
, FIX(0.399234004)); /* (c8-c14)/2 */
2468 tmp25
= tmp13
- tmp10
- tmp11
;
2469 tmp26
= tmp12
+ tmp10
- tmp11
- z2
;
2471 tmp10
= MULTIPLY(z3
, FIX(0.790569415)); /* (c6+c12)/2 */
2472 tmp11
= MULTIPLY(z4
, FIX(0.353553391)); /* (c6-c12)/2 */
2474 tmp21
= tmp12
+ tmp10
+ tmp11
;
2475 tmp24
= tmp13
- tmp10
+ tmp11
;
2477 tmp22
= z1
+ tmp11
; /* c10 = c6-c12 */
2478 tmp27
= z1
- tmp11
- tmp11
; /* c0 = (c6-c12)*2 */
2482 z1
= (INT32
) wsptr
[1];
2483 z2
= (INT32
) wsptr
[3];
2484 z4
= (INT32
) wsptr
[5];
2485 z3
= MULTIPLY(z4
, FIX(1.224744871)); /* c5 */
2486 z4
= (INT32
) wsptr
[7];
2489 tmp15
= MULTIPLY(z1
+ tmp13
, FIX(0.831253876)); /* c9 */
2490 tmp11
= tmp15
+ MULTIPLY(z1
, FIX(0.513743148)); /* c3-c9 */
2491 tmp14
= tmp15
- MULTIPLY(tmp13
, FIX(2.176250899)); /* c3+c9 */
2493 tmp13
= MULTIPLY(z2
, - FIX(0.831253876)); /* -c9 */
2494 tmp15
= MULTIPLY(z2
, - FIX(1.344997024)); /* -c3 */
2496 tmp12
= z3
+ MULTIPLY(z2
, FIX(1.406466353)); /* c1 */
2498 tmp10
= tmp12
+ MULTIPLY(z4
, FIX(2.457431844)) - tmp15
; /* c1+c7 */
2499 tmp16
= tmp12
- MULTIPLY(z1
, FIX(1.112434820)) + tmp13
; /* c1-c13 */
2500 tmp12
= MULTIPLY(z2
, FIX(1.224744871)) - z3
; /* c5 */
2501 z2
= MULTIPLY(z1
+ z4
, FIX(0.575212477)); /* c11 */
2502 tmp13
+= z2
+ MULTIPLY(z1
, FIX(0.475753014)) - z3
; /* c7-c11 */
2503 tmp15
+= z2
- MULTIPLY(z4
, FIX(0.869244010)) + z3
; /* c11+c13 */
2505 /* Final output stage */
2507 outptr
[0] = range_limit
[(int) RIGHT_SHIFT(tmp20
+ tmp10
,
2508 CONST_BITS
+PASS1_BITS
+3)
2510 outptr
[14] = range_limit
[(int) RIGHT_SHIFT(tmp20
- tmp10
,
2511 CONST_BITS
+PASS1_BITS
+3)
2513 outptr
[1] = range_limit
[(int) RIGHT_SHIFT(tmp21
+ tmp11
,
2514 CONST_BITS
+PASS1_BITS
+3)
2516 outptr
[13] = range_limit
[(int) RIGHT_SHIFT(tmp21
- tmp11
,
2517 CONST_BITS
+PASS1_BITS
+3)
2519 outptr
[2] = range_limit
[(int) RIGHT_SHIFT(tmp22
+ tmp12
,
2520 CONST_BITS
+PASS1_BITS
+3)
2522 outptr
[12] = range_limit
[(int) RIGHT_SHIFT(tmp22
- tmp12
,
2523 CONST_BITS
+PASS1_BITS
+3)
2525 outptr
[3] = range_limit
[(int) RIGHT_SHIFT(tmp23
+ tmp13
,
2526 CONST_BITS
+PASS1_BITS
+3)
2528 outptr
[11] = range_limit
[(int) RIGHT_SHIFT(tmp23
- tmp13
,
2529 CONST_BITS
+PASS1_BITS
+3)
2531 outptr
[4] = range_limit
[(int) RIGHT_SHIFT(tmp24
+ tmp14
,
2532 CONST_BITS
+PASS1_BITS
+3)
2534 outptr
[10] = range_limit
[(int) RIGHT_SHIFT(tmp24
- tmp14
,
2535 CONST_BITS
+PASS1_BITS
+3)
2537 outptr
[5] = range_limit
[(int) RIGHT_SHIFT(tmp25
+ tmp15
,
2538 CONST_BITS
+PASS1_BITS
+3)
2540 outptr
[9] = range_limit
[(int) RIGHT_SHIFT(tmp25
- tmp15
,
2541 CONST_BITS
+PASS1_BITS
+3)
2543 outptr
[6] = range_limit
[(int) RIGHT_SHIFT(tmp26
+ tmp16
,
2544 CONST_BITS
+PASS1_BITS
+3)
2546 outptr
[8] = range_limit
[(int) RIGHT_SHIFT(tmp26
- tmp16
,
2547 CONST_BITS
+PASS1_BITS
+3)
2549 outptr
[7] = range_limit
[(int) RIGHT_SHIFT(tmp27
,
2550 CONST_BITS
+PASS1_BITS
+3)
2553 wsptr
+= 8; /* advance pointer to next row */
2559 * Perform dequantization and inverse DCT on one block of coefficients,
2560 * producing a 16x16 output block.
2562 * Optimized algorithm with 28 multiplications in the 1-D kernel.
2563 * cK represents sqrt(2) * cos(K*pi/32).
2567 jpeg_idct_16x16 (j_decompress_ptr cinfo
, jpeg_component_info
* compptr
,
2568 JCOEFPTR coef_block
,
2569 JSAMPARRAY output_buf
, JDIMENSION output_col
)
2571 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp10
, tmp11
, tmp12
, tmp13
;
2572 INT32 tmp20
, tmp21
, tmp22
, tmp23
, tmp24
, tmp25
, tmp26
, tmp27
;
2573 INT32 z1
, z2
, z3
, z4
;
2575 ISLOW_MULT_TYPE
* quantptr
;
2578 JSAMPLE
*range_limit
= IDCT_range_limit(cinfo
);
2580 int workspace
[8*16]; /* buffers data between passes */
2583 /* Pass 1: process columns from input, store into work array. */
2586 quantptr
= (ISLOW_MULT_TYPE
*) compptr
->dct_table
;
2588 for (ctr
= 0; ctr
< 8; ctr
++, inptr
++, quantptr
++, wsptr
++) {
2591 tmp0
= DEQUANTIZE(inptr
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]);
2592 tmp0
<<= CONST_BITS
;
2593 /* Add fudge factor here for final descale. */
2594 tmp0
+= 1 << (CONST_BITS
-PASS1_BITS
-1);
2596 z1
= DEQUANTIZE(inptr
[DCTSIZE
*4], quantptr
[DCTSIZE
*4]);
2597 tmp1
= MULTIPLY(z1
, FIX(1.306562965)); /* c4[16] = c2[8] */
2598 tmp2
= MULTIPLY(z1
, FIX_0_541196100
); /* c12[16] = c6[8] */
2600 tmp10
= tmp0
+ tmp1
;
2601 tmp11
= tmp0
- tmp1
;
2602 tmp12
= tmp0
+ tmp2
;
2603 tmp13
= tmp0
- tmp2
;
2605 z1
= DEQUANTIZE(inptr
[DCTSIZE
*2], quantptr
[DCTSIZE
*2]);
2606 z2
= DEQUANTIZE(inptr
[DCTSIZE
*6], quantptr
[DCTSIZE
*6]);
2608 z4
= MULTIPLY(z3
, FIX(0.275899379)); /* c14[16] = c7[8] */
2609 z3
= MULTIPLY(z3
, FIX(1.387039845)); /* c2[16] = c1[8] */
2611 tmp0
= z3
+ MULTIPLY(z2
, FIX_2_562915447
); /* (c6+c2)[16] = (c3+c1)[8] */
2612 tmp1
= z4
+ MULTIPLY(z1
, FIX_0_899976223
); /* (c6-c14)[16] = (c3-c7)[8] */
2613 tmp2
= z3
- MULTIPLY(z1
, FIX(0.601344887)); /* (c2-c10)[16] = (c1-c5)[8] */
2614 tmp3
= z4
- MULTIPLY(z2
, FIX(0.509795579)); /* (c10-c14)[16] = (c5-c7)[8] */
2616 tmp20
= tmp10
+ tmp0
;
2617 tmp27
= tmp10
- tmp0
;
2618 tmp21
= tmp12
+ tmp1
;
2619 tmp26
= tmp12
- tmp1
;
2620 tmp22
= tmp13
+ tmp2
;
2621 tmp25
= tmp13
- tmp2
;
2622 tmp23
= tmp11
+ tmp3
;
2623 tmp24
= tmp11
- tmp3
;
2627 z1
= DEQUANTIZE(inptr
[DCTSIZE
*1], quantptr
[DCTSIZE
*1]);
2628 z2
= DEQUANTIZE(inptr
[DCTSIZE
*3], quantptr
[DCTSIZE
*3]);
2629 z3
= DEQUANTIZE(inptr
[DCTSIZE
*5], quantptr
[DCTSIZE
*5]);
2630 z4
= DEQUANTIZE(inptr
[DCTSIZE
*7], quantptr
[DCTSIZE
*7]);
2634 tmp1
= MULTIPLY(z1
+ z2
, FIX(1.353318001)); /* c3 */
2635 tmp2
= MULTIPLY(tmp11
, FIX(1.247225013)); /* c5 */
2636 tmp3
= MULTIPLY(z1
+ z4
, FIX(1.093201867)); /* c7 */
2637 tmp10
= MULTIPLY(z1
- z4
, FIX(0.897167586)); /* c9 */
2638 tmp11
= MULTIPLY(tmp11
, FIX(0.666655658)); /* c11 */
2639 tmp12
= MULTIPLY(z1
- z2
, FIX(0.410524528)); /* c13 */
2640 tmp0
= tmp1
+ tmp2
+ tmp3
-
2641 MULTIPLY(z1
, FIX(2.286341144)); /* c7+c5+c3-c1 */
2642 tmp13
= tmp10
+ tmp11
+ tmp12
-
2643 MULTIPLY(z1
, FIX(1.835730603)); /* c9+c11+c13-c15 */
2644 z1
= MULTIPLY(z2
+ z3
, FIX(0.138617169)); /* c15 */
2645 tmp1
+= z1
+ MULTIPLY(z2
, FIX(0.071888074)); /* c9+c11-c3-c15 */
2646 tmp2
+= z1
- MULTIPLY(z3
, FIX(1.125726048)); /* c5+c7+c15-c3 */
2647 z1
= MULTIPLY(z3
- z2
, FIX(1.407403738)); /* c1 */
2648 tmp11
+= z1
- MULTIPLY(z3
, FIX(0.766367282)); /* c1+c11-c9-c13 */
2649 tmp12
+= z1
+ MULTIPLY(z2
, FIX(1.971951411)); /* c1+c5+c13-c7 */
2651 z1
= MULTIPLY(z2
, - FIX(0.666655658)); /* -c11 */
2653 tmp3
+= z1
+ MULTIPLY(z4
, FIX(1.065388962)); /* c3+c11+c15-c7 */
2654 z2
= MULTIPLY(z2
, - FIX(1.247225013)); /* -c5 */
2655 tmp10
+= z2
+ MULTIPLY(z4
, FIX(3.141271809)); /* c1+c5+c9-c13 */
2657 z2
= MULTIPLY(z3
+ z4
, - FIX(1.353318001)); /* -c3 */
2660 z2
= MULTIPLY(z4
- z3
, FIX(0.410524528)); /* c13 */
2664 /* Final output stage */
2666 wsptr
[8*0] = (int) RIGHT_SHIFT(tmp20
+ tmp0
, CONST_BITS
-PASS1_BITS
);
2667 wsptr
[8*15] = (int) RIGHT_SHIFT(tmp20
- tmp0
, CONST_BITS
-PASS1_BITS
);
2668 wsptr
[8*1] = (int) RIGHT_SHIFT(tmp21
+ tmp1
, CONST_BITS
-PASS1_BITS
);
2669 wsptr
[8*14] = (int) RIGHT_SHIFT(tmp21
- tmp1
, CONST_BITS
-PASS1_BITS
);
2670 wsptr
[8*2] = (int) RIGHT_SHIFT(tmp22
+ tmp2
, CONST_BITS
-PASS1_BITS
);
2671 wsptr
[8*13] = (int) RIGHT_SHIFT(tmp22
- tmp2
, CONST_BITS
-PASS1_BITS
);
2672 wsptr
[8*3] = (int) RIGHT_SHIFT(tmp23
+ tmp3
, CONST_BITS
-PASS1_BITS
);
2673 wsptr
[8*12] = (int) RIGHT_SHIFT(tmp23
- tmp3
, CONST_BITS
-PASS1_BITS
);
2674 wsptr
[8*4] = (int) RIGHT_SHIFT(tmp24
+ tmp10
, CONST_BITS
-PASS1_BITS
);
2675 wsptr
[8*11] = (int) RIGHT_SHIFT(tmp24
- tmp10
, CONST_BITS
-PASS1_BITS
);
2676 wsptr
[8*5] = (int) RIGHT_SHIFT(tmp25
+ tmp11
, CONST_BITS
-PASS1_BITS
);
2677 wsptr
[8*10] = (int) RIGHT_SHIFT(tmp25
- tmp11
, CONST_BITS
-PASS1_BITS
);
2678 wsptr
[8*6] = (int) RIGHT_SHIFT(tmp26
+ tmp12
, CONST_BITS
-PASS1_BITS
);
2679 wsptr
[8*9] = (int) RIGHT_SHIFT(tmp26
- tmp12
, CONST_BITS
-PASS1_BITS
);
2680 wsptr
[8*7] = (int) RIGHT_SHIFT(tmp27
+ tmp13
, CONST_BITS
-PASS1_BITS
);
2681 wsptr
[8*8] = (int) RIGHT_SHIFT(tmp27
- tmp13
, CONST_BITS
-PASS1_BITS
);
2684 /* Pass 2: process 16 rows from work array, store into output array. */
2687 for (ctr
= 0; ctr
< 16; ctr
++) {
2688 outptr
= output_buf
[ctr
] + output_col
;
2692 /* Add fudge factor here for final descale. */
2693 tmp0
= (INT32
) wsptr
[0] + (ONE
<< (PASS1_BITS
+2));
2694 tmp0
<<= CONST_BITS
;
2696 z1
= (INT32
) wsptr
[4];
2697 tmp1
= MULTIPLY(z1
, FIX(1.306562965)); /* c4[16] = c2[8] */
2698 tmp2
= MULTIPLY(z1
, FIX_0_541196100
); /* c12[16] = c6[8] */
2700 tmp10
= tmp0
+ tmp1
;
2701 tmp11
= tmp0
- tmp1
;
2702 tmp12
= tmp0
+ tmp2
;
2703 tmp13
= tmp0
- tmp2
;
2705 z1
= (INT32
) wsptr
[2];
2706 z2
= (INT32
) wsptr
[6];
2708 z4
= MULTIPLY(z3
, FIX(0.275899379)); /* c14[16] = c7[8] */
2709 z3
= MULTIPLY(z3
, FIX(1.387039845)); /* c2[16] = c1[8] */
2711 tmp0
= z3
+ MULTIPLY(z2
, FIX_2_562915447
); /* (c6+c2)[16] = (c3+c1)[8] */
2712 tmp1
= z4
+ MULTIPLY(z1
, FIX_0_899976223
); /* (c6-c14)[16] = (c3-c7)[8] */
2713 tmp2
= z3
- MULTIPLY(z1
, FIX(0.601344887)); /* (c2-c10)[16] = (c1-c5)[8] */
2714 tmp3
= z4
- MULTIPLY(z2
, FIX(0.509795579)); /* (c10-c14)[16] = (c5-c7)[8] */
2716 tmp20
= tmp10
+ tmp0
;
2717 tmp27
= tmp10
- tmp0
;
2718 tmp21
= tmp12
+ tmp1
;
2719 tmp26
= tmp12
- tmp1
;
2720 tmp22
= tmp13
+ tmp2
;
2721 tmp25
= tmp13
- tmp2
;
2722 tmp23
= tmp11
+ tmp3
;
2723 tmp24
= tmp11
- tmp3
;
2727 z1
= (INT32
) wsptr
[1];
2728 z2
= (INT32
) wsptr
[3];
2729 z3
= (INT32
) wsptr
[5];
2730 z4
= (INT32
) wsptr
[7];
2734 tmp1
= MULTIPLY(z1
+ z2
, FIX(1.353318001)); /* c3 */
2735 tmp2
= MULTIPLY(tmp11
, FIX(1.247225013)); /* c5 */
2736 tmp3
= MULTIPLY(z1
+ z4
, FIX(1.093201867)); /* c7 */
2737 tmp10
= MULTIPLY(z1
- z4
, FIX(0.897167586)); /* c9 */
2738 tmp11
= MULTIPLY(tmp11
, FIX(0.666655658)); /* c11 */
2739 tmp12
= MULTIPLY(z1
- z2
, FIX(0.410524528)); /* c13 */
2740 tmp0
= tmp1
+ tmp2
+ tmp3
-
2741 MULTIPLY(z1
, FIX(2.286341144)); /* c7+c5+c3-c1 */
2742 tmp13
= tmp10
+ tmp11
+ tmp12
-
2743 MULTIPLY(z1
, FIX(1.835730603)); /* c9+c11+c13-c15 */
2744 z1
= MULTIPLY(z2
+ z3
, FIX(0.138617169)); /* c15 */
2745 tmp1
+= z1
+ MULTIPLY(z2
, FIX(0.071888074)); /* c9+c11-c3-c15 */
2746 tmp2
+= z1
- MULTIPLY(z3
, FIX(1.125726048)); /* c5+c7+c15-c3 */
2747 z1
= MULTIPLY(z3
- z2
, FIX(1.407403738)); /* c1 */
2748 tmp11
+= z1
- MULTIPLY(z3
, FIX(0.766367282)); /* c1+c11-c9-c13 */
2749 tmp12
+= z1
+ MULTIPLY(z2
, FIX(1.971951411)); /* c1+c5+c13-c7 */
2751 z1
= MULTIPLY(z2
, - FIX(0.666655658)); /* -c11 */
2753 tmp3
+= z1
+ MULTIPLY(z4
, FIX(1.065388962)); /* c3+c11+c15-c7 */
2754 z2
= MULTIPLY(z2
, - FIX(1.247225013)); /* -c5 */
2755 tmp10
+= z2
+ MULTIPLY(z4
, FIX(3.141271809)); /* c1+c5+c9-c13 */
2757 z2
= MULTIPLY(z3
+ z4
, - FIX(1.353318001)); /* -c3 */
2760 z2
= MULTIPLY(z4
- z3
, FIX(0.410524528)); /* c13 */
2764 /* Final output stage */
2766 outptr
[0] = range_limit
[(int) RIGHT_SHIFT(tmp20
+ tmp0
,
2767 CONST_BITS
+PASS1_BITS
+3)
2769 outptr
[15] = range_limit
[(int) RIGHT_SHIFT(tmp20
- tmp0
,
2770 CONST_BITS
+PASS1_BITS
+3)
2772 outptr
[1] = range_limit
[(int) RIGHT_SHIFT(tmp21
+ tmp1
,
2773 CONST_BITS
+PASS1_BITS
+3)
2775 outptr
[14] = range_limit
[(int) RIGHT_SHIFT(tmp21
- tmp1
,
2776 CONST_BITS
+PASS1_BITS
+3)
2778 outptr
[2] = range_limit
[(int) RIGHT_SHIFT(tmp22
+ tmp2
,
2779 CONST_BITS
+PASS1_BITS
+3)
2781 outptr
[13] = range_limit
[(int) RIGHT_SHIFT(tmp22
- tmp2
,
2782 CONST_BITS
+PASS1_BITS
+3)
2784 outptr
[3] = range_limit
[(int) RIGHT_SHIFT(tmp23
+ tmp3
,
2785 CONST_BITS
+PASS1_BITS
+3)
2787 outptr
[12] = range_limit
[(int) RIGHT_SHIFT(tmp23
- tmp3
,
2788 CONST_BITS
+PASS1_BITS
+3)
2790 outptr
[4] = range_limit
[(int) RIGHT_SHIFT(tmp24
+ tmp10
,
2791 CONST_BITS
+PASS1_BITS
+3)
2793 outptr
[11] = range_limit
[(int) RIGHT_SHIFT(tmp24
- tmp10
,
2794 CONST_BITS
+PASS1_BITS
+3)
2796 outptr
[5] = range_limit
[(int) RIGHT_SHIFT(tmp25
+ tmp11
,
2797 CONST_BITS
+PASS1_BITS
+3)
2799 outptr
[10] = range_limit
[(int) RIGHT_SHIFT(tmp25
- tmp11
,
2800 CONST_BITS
+PASS1_BITS
+3)
2802 outptr
[6] = range_limit
[(int) RIGHT_SHIFT(tmp26
+ tmp12
,
2803 CONST_BITS
+PASS1_BITS
+3)
2805 outptr
[9] = range_limit
[(int) RIGHT_SHIFT(tmp26
- tmp12
,
2806 CONST_BITS
+PASS1_BITS
+3)
2808 outptr
[7] = range_limit
[(int) RIGHT_SHIFT(tmp27
+ tmp13
,
2809 CONST_BITS
+PASS1_BITS
+3)
2811 outptr
[8] = range_limit
[(int) RIGHT_SHIFT(tmp27
- tmp13
,
2812 CONST_BITS
+PASS1_BITS
+3)
2815 wsptr
+= 8; /* advance pointer to next row */
2821 * Perform dequantization and inverse DCT on one block of coefficients,
2822 * producing a 16x8 output block.
2824 * 8-point IDCT in pass 1 (columns), 16-point in pass 2 (rows).
2828 jpeg_idct_16x8 (j_decompress_ptr cinfo
, jpeg_component_info
* compptr
,
2829 JCOEFPTR coef_block
,
2830 JSAMPARRAY output_buf
, JDIMENSION output_col
)
2832 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp10
, tmp11
, tmp12
, tmp13
;
2833 INT32 tmp20
, tmp21
, tmp22
, tmp23
, tmp24
, tmp25
, tmp26
, tmp27
;
2834 INT32 z1
, z2
, z3
, z4
;
2836 ISLOW_MULT_TYPE
* quantptr
;
2839 JSAMPLE
*range_limit
= IDCT_range_limit(cinfo
);
2841 int workspace
[8*8]; /* buffers data between passes */
2844 /* Pass 1: process columns from input, store into work array.
2845 * Note results are scaled up by sqrt(8) compared to a true IDCT;
2846 * furthermore, we scale the results by 2**PASS1_BITS.
2847 * 8-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
2851 quantptr
= (ISLOW_MULT_TYPE
*) compptr
->dct_table
;
2853 for (ctr
= DCTSIZE
; ctr
> 0; ctr
--) {
2854 /* Due to quantization, we will usually find that many of the input
2855 * coefficients are zero, especially the AC terms. We can exploit this
2856 * by short-circuiting the IDCT calculation for any column in which all
2857 * the AC terms are zero. In that case each output is equal to the
2858 * DC coefficient (with scale factor as needed).
2859 * With typical images and quantization tables, half or more of the
2860 * column DCT calculations can be simplified this way.
2863 if (inptr
[DCTSIZE
*1] == 0 && inptr
[DCTSIZE
*2] == 0 &&
2864 inptr
[DCTSIZE
*3] == 0 && inptr
[DCTSIZE
*4] == 0 &&
2865 inptr
[DCTSIZE
*5] == 0 && inptr
[DCTSIZE
*6] == 0 &&
2866 inptr
[DCTSIZE
*7] == 0) {
2867 /* AC terms all zero */
2868 int dcval
= DEQUANTIZE(inptr
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]) << PASS1_BITS
;
2870 wsptr
[DCTSIZE
*0] = dcval
;
2871 wsptr
[DCTSIZE
*1] = dcval
;
2872 wsptr
[DCTSIZE
*2] = dcval
;
2873 wsptr
[DCTSIZE
*3] = dcval
;
2874 wsptr
[DCTSIZE
*4] = dcval
;
2875 wsptr
[DCTSIZE
*5] = dcval
;
2876 wsptr
[DCTSIZE
*6] = dcval
;
2877 wsptr
[DCTSIZE
*7] = dcval
;
2879 inptr
++; /* advance pointers to next column */
2885 /* Even part: reverse the even part of the forward DCT.
2886 * The rotator is c(-6).
2889 z2
= DEQUANTIZE(inptr
[DCTSIZE
*2], quantptr
[DCTSIZE
*2]);
2890 z3
= DEQUANTIZE(inptr
[DCTSIZE
*6], quantptr
[DCTSIZE
*6]);
2892 z1
= MULTIPLY(z2
+ z3
, FIX_0_541196100
); /* c6 */
2893 tmp2
= z1
+ MULTIPLY(z2
, FIX_0_765366865
); /* c2-c6 */
2894 tmp3
= z1
- MULTIPLY(z3
, FIX_1_847759065
); /* c2+c6 */
2896 z2
= DEQUANTIZE(inptr
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]);
2897 z3
= DEQUANTIZE(inptr
[DCTSIZE
*4], quantptr
[DCTSIZE
*4]);
2900 /* Add fudge factor here for final descale. */
2901 z2
+= ONE
<< (CONST_BITS
-PASS1_BITS
-1);
2906 tmp10
= tmp0
+ tmp2
;
2907 tmp13
= tmp0
- tmp2
;
2908 tmp11
= tmp1
+ tmp3
;
2909 tmp12
= tmp1
- tmp3
;
2911 /* Odd part per figure 8; the matrix is unitary and hence its
2912 * transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively.
2915 tmp0
= DEQUANTIZE(inptr
[DCTSIZE
*7], quantptr
[DCTSIZE
*7]);
2916 tmp1
= DEQUANTIZE(inptr
[DCTSIZE
*5], quantptr
[DCTSIZE
*5]);
2917 tmp2
= DEQUANTIZE(inptr
[DCTSIZE
*3], quantptr
[DCTSIZE
*3]);
2918 tmp3
= DEQUANTIZE(inptr
[DCTSIZE
*1], quantptr
[DCTSIZE
*1]);
2923 z1
= MULTIPLY(z2
+ z3
, FIX_1_175875602
); /* c3 */
2924 z2
= MULTIPLY(z2
, - FIX_1_961570560
); /* -c3-c5 */
2925 z3
= MULTIPLY(z3
, - FIX_0_390180644
); /* -c3+c5 */
2929 z1
= MULTIPLY(tmp0
+ tmp3
, - FIX_0_899976223
); /* -c3+c7 */
2930 tmp0
= MULTIPLY(tmp0
, FIX_0_298631336
); /* -c1+c3+c5-c7 */
2931 tmp3
= MULTIPLY(tmp3
, FIX_1_501321110
); /* c1+c3-c5-c7 */
2935 z1
= MULTIPLY(tmp1
+ tmp2
, - FIX_2_562915447
); /* -c1-c3 */
2936 tmp1
= MULTIPLY(tmp1
, FIX_2_053119869
); /* c1+c3-c5+c7 */
2937 tmp2
= MULTIPLY(tmp2
, FIX_3_072711026
); /* c1+c3+c5-c7 */
2941 /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
2943 wsptr
[DCTSIZE
*0] = (int) RIGHT_SHIFT(tmp10
+ tmp3
, CONST_BITS
-PASS1_BITS
);
2944 wsptr
[DCTSIZE
*7] = (int) RIGHT_SHIFT(tmp10
- tmp3
, CONST_BITS
-PASS1_BITS
);
2945 wsptr
[DCTSIZE
*1] = (int) RIGHT_SHIFT(tmp11
+ tmp2
, CONST_BITS
-PASS1_BITS
);
2946 wsptr
[DCTSIZE
*6] = (int) RIGHT_SHIFT(tmp11
- tmp2
, CONST_BITS
-PASS1_BITS
);
2947 wsptr
[DCTSIZE
*2] = (int) RIGHT_SHIFT(tmp12
+ tmp1
, CONST_BITS
-PASS1_BITS
);
2948 wsptr
[DCTSIZE
*5] = (int) RIGHT_SHIFT(tmp12
- tmp1
, CONST_BITS
-PASS1_BITS
);
2949 wsptr
[DCTSIZE
*3] = (int) RIGHT_SHIFT(tmp13
+ tmp0
, CONST_BITS
-PASS1_BITS
);
2950 wsptr
[DCTSIZE
*4] = (int) RIGHT_SHIFT(tmp13
- tmp0
, CONST_BITS
-PASS1_BITS
);
2952 inptr
++; /* advance pointers to next column */
2957 /* Pass 2: process 8 rows from work array, store into output array.
2958 * 16-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/32).
2962 for (ctr
= 0; ctr
< 8; ctr
++) {
2963 outptr
= output_buf
[ctr
] + output_col
;
2967 /* Add fudge factor here for final descale. */
2968 tmp0
= (INT32
) wsptr
[0] + (ONE
<< (PASS1_BITS
+2));
2969 tmp0
<<= CONST_BITS
;
2971 z1
= (INT32
) wsptr
[4];
2972 tmp1
= MULTIPLY(z1
, FIX(1.306562965)); /* c4[16] = c2[8] */
2973 tmp2
= MULTIPLY(z1
, FIX_0_541196100
); /* c12[16] = c6[8] */
2975 tmp10
= tmp0
+ tmp1
;
2976 tmp11
= tmp0
- tmp1
;
2977 tmp12
= tmp0
+ tmp2
;
2978 tmp13
= tmp0
- tmp2
;
2980 z1
= (INT32
) wsptr
[2];
2981 z2
= (INT32
) wsptr
[6];
2983 z4
= MULTIPLY(z3
, FIX(0.275899379)); /* c14[16] = c7[8] */
2984 z3
= MULTIPLY(z3
, FIX(1.387039845)); /* c2[16] = c1[8] */
2986 tmp0
= z3
+ MULTIPLY(z2
, FIX_2_562915447
); /* (c6+c2)[16] = (c3+c1)[8] */
2987 tmp1
= z4
+ MULTIPLY(z1
, FIX_0_899976223
); /* (c6-c14)[16] = (c3-c7)[8] */
2988 tmp2
= z3
- MULTIPLY(z1
, FIX(0.601344887)); /* (c2-c10)[16] = (c1-c5)[8] */
2989 tmp3
= z4
- MULTIPLY(z2
, FIX(0.509795579)); /* (c10-c14)[16] = (c5-c7)[8] */
2991 tmp20
= tmp10
+ tmp0
;
2992 tmp27
= tmp10
- tmp0
;
2993 tmp21
= tmp12
+ tmp1
;
2994 tmp26
= tmp12
- tmp1
;
2995 tmp22
= tmp13
+ tmp2
;
2996 tmp25
= tmp13
- tmp2
;
2997 tmp23
= tmp11
+ tmp3
;
2998 tmp24
= tmp11
- tmp3
;
3002 z1
= (INT32
) wsptr
[1];
3003 z2
= (INT32
) wsptr
[3];
3004 z3
= (INT32
) wsptr
[5];
3005 z4
= (INT32
) wsptr
[7];
3009 tmp1
= MULTIPLY(z1
+ z2
, FIX(1.353318001)); /* c3 */
3010 tmp2
= MULTIPLY(tmp11
, FIX(1.247225013)); /* c5 */
3011 tmp3
= MULTIPLY(z1
+ z4
, FIX(1.093201867)); /* c7 */
3012 tmp10
= MULTIPLY(z1
- z4
, FIX(0.897167586)); /* c9 */
3013 tmp11
= MULTIPLY(tmp11
, FIX(0.666655658)); /* c11 */
3014 tmp12
= MULTIPLY(z1
- z2
, FIX(0.410524528)); /* c13 */
3015 tmp0
= tmp1
+ tmp2
+ tmp3
-
3016 MULTIPLY(z1
, FIX(2.286341144)); /* c7+c5+c3-c1 */
3017 tmp13
= tmp10
+ tmp11
+ tmp12
-
3018 MULTIPLY(z1
, FIX(1.835730603)); /* c9+c11+c13-c15 */
3019 z1
= MULTIPLY(z2
+ z3
, FIX(0.138617169)); /* c15 */
3020 tmp1
+= z1
+ MULTIPLY(z2
, FIX(0.071888074)); /* c9+c11-c3-c15 */
3021 tmp2
+= z1
- MULTIPLY(z3
, FIX(1.125726048)); /* c5+c7+c15-c3 */
3022 z1
= MULTIPLY(z3
- z2
, FIX(1.407403738)); /* c1 */
3023 tmp11
+= z1
- MULTIPLY(z3
, FIX(0.766367282)); /* c1+c11-c9-c13 */
3024 tmp12
+= z1
+ MULTIPLY(z2
, FIX(1.971951411)); /* c1+c5+c13-c7 */
3026 z1
= MULTIPLY(z2
, - FIX(0.666655658)); /* -c11 */
3028 tmp3
+= z1
+ MULTIPLY(z4
, FIX(1.065388962)); /* c3+c11+c15-c7 */
3029 z2
= MULTIPLY(z2
, - FIX(1.247225013)); /* -c5 */
3030 tmp10
+= z2
+ MULTIPLY(z4
, FIX(3.141271809)); /* c1+c5+c9-c13 */
3032 z2
= MULTIPLY(z3
+ z4
, - FIX(1.353318001)); /* -c3 */
3035 z2
= MULTIPLY(z4
- z3
, FIX(0.410524528)); /* c13 */
3039 /* Final output stage */
3041 outptr
[0] = range_limit
[(int) RIGHT_SHIFT(tmp20
+ tmp0
,
3042 CONST_BITS
+PASS1_BITS
+3)
3044 outptr
[15] = range_limit
[(int) RIGHT_SHIFT(tmp20
- tmp0
,
3045 CONST_BITS
+PASS1_BITS
+3)
3047 outptr
[1] = range_limit
[(int) RIGHT_SHIFT(tmp21
+ tmp1
,
3048 CONST_BITS
+PASS1_BITS
+3)
3050 outptr
[14] = range_limit
[(int) RIGHT_SHIFT(tmp21
- tmp1
,
3051 CONST_BITS
+PASS1_BITS
+3)
3053 outptr
[2] = range_limit
[(int) RIGHT_SHIFT(tmp22
+ tmp2
,
3054 CONST_BITS
+PASS1_BITS
+3)
3056 outptr
[13] = range_limit
[(int) RIGHT_SHIFT(tmp22
- tmp2
,
3057 CONST_BITS
+PASS1_BITS
+3)
3059 outptr
[3] = range_limit
[(int) RIGHT_SHIFT(tmp23
+ tmp3
,
3060 CONST_BITS
+PASS1_BITS
+3)
3062 outptr
[12] = range_limit
[(int) RIGHT_SHIFT(tmp23
- tmp3
,
3063 CONST_BITS
+PASS1_BITS
+3)
3065 outptr
[4] = range_limit
[(int) RIGHT_SHIFT(tmp24
+ tmp10
,
3066 CONST_BITS
+PASS1_BITS
+3)
3068 outptr
[11] = range_limit
[(int) RIGHT_SHIFT(tmp24
- tmp10
,
3069 CONST_BITS
+PASS1_BITS
+3)
3071 outptr
[5] = range_limit
[(int) RIGHT_SHIFT(tmp25
+ tmp11
,
3072 CONST_BITS
+PASS1_BITS
+3)
3074 outptr
[10] = range_limit
[(int) RIGHT_SHIFT(tmp25
- tmp11
,
3075 CONST_BITS
+PASS1_BITS
+3)
3077 outptr
[6] = range_limit
[(int) RIGHT_SHIFT(tmp26
+ tmp12
,
3078 CONST_BITS
+PASS1_BITS
+3)
3080 outptr
[9] = range_limit
[(int) RIGHT_SHIFT(tmp26
- tmp12
,
3081 CONST_BITS
+PASS1_BITS
+3)
3083 outptr
[7] = range_limit
[(int) RIGHT_SHIFT(tmp27
+ tmp13
,
3084 CONST_BITS
+PASS1_BITS
+3)
3086 outptr
[8] = range_limit
[(int) RIGHT_SHIFT(tmp27
- tmp13
,
3087 CONST_BITS
+PASS1_BITS
+3)
3090 wsptr
+= 8; /* advance pointer to next row */
3096 * Perform dequantization and inverse DCT on one block of coefficients,
3097 * producing a 14x7 output block.
3099 * 7-point IDCT in pass 1 (columns), 14-point in pass 2 (rows).
3103 jpeg_idct_14x7 (j_decompress_ptr cinfo
, jpeg_component_info
* compptr
,
3104 JCOEFPTR coef_block
,
3105 JSAMPARRAY output_buf
, JDIMENSION output_col
)
3107 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
, tmp15
, tmp16
;
3108 INT32 tmp20
, tmp21
, tmp22
, tmp23
, tmp24
, tmp25
, tmp26
;
3109 INT32 z1
, z2
, z3
, z4
;
3111 ISLOW_MULT_TYPE
* quantptr
;
3114 JSAMPLE
*range_limit
= IDCT_range_limit(cinfo
);
3116 int workspace
[8*7]; /* buffers data between passes */
3119 /* Pass 1: process columns from input, store into work array.
3120 * 7-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/14).
3124 quantptr
= (ISLOW_MULT_TYPE
*) compptr
->dct_table
;
3126 for (ctr
= 0; ctr
< 8; ctr
++, inptr
++, quantptr
++, wsptr
++) {
3129 tmp23
= DEQUANTIZE(inptr
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]);
3130 tmp23
<<= CONST_BITS
;
3131 /* Add fudge factor here for final descale. */
3132 tmp23
+= ONE
<< (CONST_BITS
-PASS1_BITS
-1);
3134 z1
= DEQUANTIZE(inptr
[DCTSIZE
*2], quantptr
[DCTSIZE
*2]);
3135 z2
= DEQUANTIZE(inptr
[DCTSIZE
*4], quantptr
[DCTSIZE
*4]);
3136 z3
= DEQUANTIZE(inptr
[DCTSIZE
*6], quantptr
[DCTSIZE
*6]);
3138 tmp20
= MULTIPLY(z2
- z3
, FIX(0.881747734)); /* c4 */
3139 tmp22
= MULTIPLY(z1
- z2
, FIX(0.314692123)); /* c6 */
3140 tmp21
= tmp20
+ tmp22
+ tmp23
- MULTIPLY(z2
, FIX(1.841218003)); /* c2+c4-c6 */
3143 tmp10
= MULTIPLY(tmp10
, FIX(1.274162392)) + tmp23
; /* c2 */
3144 tmp20
+= tmp10
- MULTIPLY(z3
, FIX(0.077722536)); /* c2-c4-c6 */
3145 tmp22
+= tmp10
- MULTIPLY(z1
, FIX(2.470602249)); /* c2+c4+c6 */
3146 tmp23
+= MULTIPLY(z2
, FIX(1.414213562)); /* c0 */
3150 z1
= DEQUANTIZE(inptr
[DCTSIZE
*1], quantptr
[DCTSIZE
*1]);
3151 z2
= DEQUANTIZE(inptr
[DCTSIZE
*3], quantptr
[DCTSIZE
*3]);
3152 z3
= DEQUANTIZE(inptr
[DCTSIZE
*5], quantptr
[DCTSIZE
*5]);
3154 tmp11
= MULTIPLY(z1
+ z2
, FIX(0.935414347)); /* (c3+c1-c5)/2 */
3155 tmp12
= MULTIPLY(z1
- z2
, FIX(0.170262339)); /* (c3+c5-c1)/2 */
3156 tmp10
= tmp11
- tmp12
;
3158 tmp12
= MULTIPLY(z2
+ z3
, - FIX(1.378756276)); /* -c1 */
3160 z2
= MULTIPLY(z1
+ z3
, FIX(0.613604268)); /* c5 */
3162 tmp12
+= z2
+ MULTIPLY(z3
, FIX(1.870828693)); /* c3+c1-c5 */
3164 /* Final output stage */
3166 wsptr
[8*0] = (int) RIGHT_SHIFT(tmp20
+ tmp10
, CONST_BITS
-PASS1_BITS
);
3167 wsptr
[8*6] = (int) RIGHT_SHIFT(tmp20
- tmp10
, CONST_BITS
-PASS1_BITS
);
3168 wsptr
[8*1] = (int) RIGHT_SHIFT(tmp21
+ tmp11
, CONST_BITS
-PASS1_BITS
);
3169 wsptr
[8*5] = (int) RIGHT_SHIFT(tmp21
- tmp11
, CONST_BITS
-PASS1_BITS
);
3170 wsptr
[8*2] = (int) RIGHT_SHIFT(tmp22
+ tmp12
, CONST_BITS
-PASS1_BITS
);
3171 wsptr
[8*4] = (int) RIGHT_SHIFT(tmp22
- tmp12
, CONST_BITS
-PASS1_BITS
);
3172 wsptr
[8*3] = (int) RIGHT_SHIFT(tmp23
, CONST_BITS
-PASS1_BITS
);
3175 /* Pass 2: process 7 rows from work array, store into output array.
3176 * 14-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/28).
3180 for (ctr
= 0; ctr
< 7; ctr
++) {
3181 outptr
= output_buf
[ctr
] + output_col
;
3185 /* Add fudge factor here for final descale. */
3186 z1
= (INT32
) wsptr
[0] + (ONE
<< (PASS1_BITS
+2));
3188 z4
= (INT32
) wsptr
[4];
3189 z2
= MULTIPLY(z4
, FIX(1.274162392)); /* c4 */
3190 z3
= MULTIPLY(z4
, FIX(0.314692123)); /* c12 */
3191 z4
= MULTIPLY(z4
, FIX(0.881747734)); /* c8 */
3197 tmp23
= z1
- ((z2
+ z3
- z4
) << 1); /* c0 = (c4+c12-c8)*2 */
3199 z1
= (INT32
) wsptr
[2];
3200 z2
= (INT32
) wsptr
[6];
3202 z3
= MULTIPLY(z1
+ z2
, FIX(1.105676686)); /* c6 */
3204 tmp13
= z3
+ MULTIPLY(z1
, FIX(0.273079590)); /* c2-c6 */
3205 tmp14
= z3
- MULTIPLY(z2
, FIX(1.719280954)); /* c6+c10 */
3206 tmp15
= MULTIPLY(z1
, FIX(0.613604268)) - /* c10 */
3207 MULTIPLY(z2
, FIX(1.378756276)); /* c2 */
3209 tmp20
= tmp10
+ tmp13
;
3210 tmp26
= tmp10
- tmp13
;
3211 tmp21
= tmp11
+ tmp14
;
3212 tmp25
= tmp11
- tmp14
;
3213 tmp22
= tmp12
+ tmp15
;
3214 tmp24
= tmp12
- tmp15
;
3218 z1
= (INT32
) wsptr
[1];
3219 z2
= (INT32
) wsptr
[3];
3220 z3
= (INT32
) wsptr
[5];
3221 z4
= (INT32
) wsptr
[7];
3225 tmp11
= MULTIPLY(z1
+ z2
, FIX(1.334852607)); /* c3 */
3226 tmp12
= MULTIPLY(tmp14
, FIX(1.197448846)); /* c5 */
3227 tmp10
= tmp11
+ tmp12
+ z4
- MULTIPLY(z1
, FIX(1.126980169)); /* c3+c5-c1 */
3228 tmp14
= MULTIPLY(tmp14
, FIX(0.752406978)); /* c9 */
3229 tmp16
= tmp14
- MULTIPLY(z1
, FIX(1.061150426)); /* c9+c11-c13 */
3231 tmp15
= MULTIPLY(z1
, FIX(0.467085129)) - z4
; /* c11 */
3233 tmp13
= MULTIPLY(z2
+ z3
, - FIX(0.158341681)) - z4
; /* -c13 */
3234 tmp11
+= tmp13
- MULTIPLY(z2
, FIX(0.424103948)); /* c3-c9-c13 */
3235 tmp12
+= tmp13
- MULTIPLY(z3
, FIX(2.373959773)); /* c3+c5-c13 */
3236 tmp13
= MULTIPLY(z3
- z2
, FIX(1.405321284)); /* c1 */
3237 tmp14
+= tmp13
+ z4
- MULTIPLY(z3
, FIX(1.6906431334)); /* c1+c9-c11 */
3238 tmp15
+= tmp13
+ MULTIPLY(z2
, FIX(0.674957567)); /* c1+c11-c5 */
3240 tmp13
= ((z1
- z3
) << CONST_BITS
) + z4
;
3242 /* Final output stage */
3244 outptr
[0] = range_limit
[(int) RIGHT_SHIFT(tmp20
+ tmp10
,
3245 CONST_BITS
+PASS1_BITS
+3)
3247 outptr
[13] = range_limit
[(int) RIGHT_SHIFT(tmp20
- tmp10
,
3248 CONST_BITS
+PASS1_BITS
+3)
3250 outptr
[1] = range_limit
[(int) RIGHT_SHIFT(tmp21
+ tmp11
,
3251 CONST_BITS
+PASS1_BITS
+3)
3253 outptr
[12] = range_limit
[(int) RIGHT_SHIFT(tmp21
- tmp11
,
3254 CONST_BITS
+PASS1_BITS
+3)
3256 outptr
[2] = range_limit
[(int) RIGHT_SHIFT(tmp22
+ tmp12
,
3257 CONST_BITS
+PASS1_BITS
+3)
3259 outptr
[11] = range_limit
[(int) RIGHT_SHIFT(tmp22
- tmp12
,
3260 CONST_BITS
+PASS1_BITS
+3)
3262 outptr
[3] = range_limit
[(int) RIGHT_SHIFT(tmp23
+ tmp13
,
3263 CONST_BITS
+PASS1_BITS
+3)
3265 outptr
[10] = range_limit
[(int) RIGHT_SHIFT(tmp23
- tmp13
,
3266 CONST_BITS
+PASS1_BITS
+3)
3268 outptr
[4] = range_limit
[(int) RIGHT_SHIFT(tmp24
+ tmp14
,
3269 CONST_BITS
+PASS1_BITS
+3)
3271 outptr
[9] = range_limit
[(int) RIGHT_SHIFT(tmp24
- tmp14
,
3272 CONST_BITS
+PASS1_BITS
+3)
3274 outptr
[5] = range_limit
[(int) RIGHT_SHIFT(tmp25
+ tmp15
,
3275 CONST_BITS
+PASS1_BITS
+3)
3277 outptr
[8] = range_limit
[(int) RIGHT_SHIFT(tmp25
- tmp15
,
3278 CONST_BITS
+PASS1_BITS
+3)
3280 outptr
[6] = range_limit
[(int) RIGHT_SHIFT(tmp26
+ tmp16
,
3281 CONST_BITS
+PASS1_BITS
+3)
3283 outptr
[7] = range_limit
[(int) RIGHT_SHIFT(tmp26
- tmp16
,
3284 CONST_BITS
+PASS1_BITS
+3)
3287 wsptr
+= 8; /* advance pointer to next row */
3293 * Perform dequantization and inverse DCT on one block of coefficients,
3294 * producing a 12x6 output block.
3296 * 6-point IDCT in pass 1 (columns), 12-point in pass 2 (rows).
3300 jpeg_idct_12x6 (j_decompress_ptr cinfo
, jpeg_component_info
* compptr
,
3301 JCOEFPTR coef_block
,
3302 JSAMPARRAY output_buf
, JDIMENSION output_col
)
3304 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
, tmp15
;
3305 INT32 tmp20
, tmp21
, tmp22
, tmp23
, tmp24
, tmp25
;
3306 INT32 z1
, z2
, z3
, z4
;
3308 ISLOW_MULT_TYPE
* quantptr
;
3311 JSAMPLE
*range_limit
= IDCT_range_limit(cinfo
);
3313 int workspace
[8*6]; /* buffers data between passes */
3316 /* Pass 1: process columns from input, store into work array.
3317 * 6-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/12).
3321 quantptr
= (ISLOW_MULT_TYPE
*) compptr
->dct_table
;
3323 for (ctr
= 0; ctr
< 8; ctr
++, inptr
++, quantptr
++, wsptr
++) {
3326 tmp10
= DEQUANTIZE(inptr
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]);
3327 tmp10
<<= CONST_BITS
;
3328 /* Add fudge factor here for final descale. */
3329 tmp10
+= ONE
<< (CONST_BITS
-PASS1_BITS
-1);
3330 tmp12
= DEQUANTIZE(inptr
[DCTSIZE
*4], quantptr
[DCTSIZE
*4]);
3331 tmp20
= MULTIPLY(tmp12
, FIX(0.707106781)); /* c4 */
3332 tmp11
= tmp10
+ tmp20
;
3333 tmp21
= RIGHT_SHIFT(tmp10
- tmp20
- tmp20
, CONST_BITS
-PASS1_BITS
);
3334 tmp20
= DEQUANTIZE(inptr
[DCTSIZE
*2], quantptr
[DCTSIZE
*2]);
3335 tmp10
= MULTIPLY(tmp20
, FIX(1.224744871)); /* c2 */
3336 tmp20
= tmp11
+ tmp10
;
3337 tmp22
= tmp11
- tmp10
;
3341 z1
= DEQUANTIZE(inptr
[DCTSIZE
*1], quantptr
[DCTSIZE
*1]);
3342 z2
= DEQUANTIZE(inptr
[DCTSIZE
*3], quantptr
[DCTSIZE
*3]);
3343 z3
= DEQUANTIZE(inptr
[DCTSIZE
*5], quantptr
[DCTSIZE
*5]);
3344 tmp11
= MULTIPLY(z1
+ z3
, FIX(0.366025404)); /* c5 */
3345 tmp10
= tmp11
+ ((z1
+ z2
) << CONST_BITS
);
3346 tmp12
= tmp11
+ ((z3
- z2
) << CONST_BITS
);
3347 tmp11
= (z1
- z2
- z3
) << PASS1_BITS
;
3349 /* Final output stage */
3351 wsptr
[8*0] = (int) RIGHT_SHIFT(tmp20
+ tmp10
, CONST_BITS
-PASS1_BITS
);
3352 wsptr
[8*5] = (int) RIGHT_SHIFT(tmp20
- tmp10
, CONST_BITS
-PASS1_BITS
);
3353 wsptr
[8*1] = (int) (tmp21
+ tmp11
);
3354 wsptr
[8*4] = (int) (tmp21
- tmp11
);
3355 wsptr
[8*2] = (int) RIGHT_SHIFT(tmp22
+ tmp12
, CONST_BITS
-PASS1_BITS
);
3356 wsptr
[8*3] = (int) RIGHT_SHIFT(tmp22
- tmp12
, CONST_BITS
-PASS1_BITS
);
3359 /* Pass 2: process 6 rows from work array, store into output array.
3360 * 12-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/24).
3364 for (ctr
= 0; ctr
< 6; ctr
++) {
3365 outptr
= output_buf
[ctr
] + output_col
;
3369 /* Add fudge factor here for final descale. */
3370 z3
= (INT32
) wsptr
[0] + (ONE
<< (PASS1_BITS
+2));
3373 z4
= (INT32
) wsptr
[4];
3374 z4
= MULTIPLY(z4
, FIX(1.224744871)); /* c4 */
3379 z1
= (INT32
) wsptr
[2];
3380 z4
= MULTIPLY(z1
, FIX(1.366025404)); /* c2 */
3382 z2
= (INT32
) wsptr
[6];
3392 tmp20
= tmp10
+ tmp12
;
3393 tmp25
= tmp10
- tmp12
;
3395 tmp12
= z4
- z1
- z2
;
3397 tmp22
= tmp11
+ tmp12
;
3398 tmp23
= tmp11
- tmp12
;
3402 z1
= (INT32
) wsptr
[1];
3403 z2
= (INT32
) wsptr
[3];
3404 z3
= (INT32
) wsptr
[5];
3405 z4
= (INT32
) wsptr
[7];
3407 tmp11
= MULTIPLY(z2
, FIX(1.306562965)); /* c3 */
3408 tmp14
= MULTIPLY(z2
, - FIX_0_541196100
); /* -c9 */
3411 tmp15
= MULTIPLY(tmp10
+ z4
, FIX(0.860918669)); /* c7 */
3412 tmp12
= tmp15
+ MULTIPLY(tmp10
, FIX(0.261052384)); /* c5-c7 */
3413 tmp10
= tmp12
+ tmp11
+ MULTIPLY(z1
, FIX(0.280143716)); /* c1-c5 */
3414 tmp13
= MULTIPLY(z3
+ z4
, - FIX(1.045510580)); /* -(c7+c11) */
3415 tmp12
+= tmp13
+ tmp14
- MULTIPLY(z3
, FIX(1.478575242)); /* c1+c5-c7-c11 */
3416 tmp13
+= tmp15
- tmp11
+ MULTIPLY(z4
, FIX(1.586706681)); /* c1+c11 */
3417 tmp15
+= tmp14
- MULTIPLY(z1
, FIX(0.676326758)) - /* c7-c11 */
3418 MULTIPLY(z4
, FIX(1.982889723)); /* c5+c7 */
3422 z3
= MULTIPLY(z1
+ z2
, FIX_0_541196100
); /* c9 */
3423 tmp11
= z3
+ MULTIPLY(z1
, FIX_0_765366865
); /* c3-c9 */
3424 tmp14
= z3
- MULTIPLY(z2
, FIX_1_847759065
); /* c3+c9 */
3426 /* Final output stage */
3428 outptr
[0] = range_limit
[(int) RIGHT_SHIFT(tmp20
+ tmp10
,
3429 CONST_BITS
+PASS1_BITS
+3)
3431 outptr
[11] = range_limit
[(int) RIGHT_SHIFT(tmp20
- tmp10
,
3432 CONST_BITS
+PASS1_BITS
+3)
3434 outptr
[1] = range_limit
[(int) RIGHT_SHIFT(tmp21
+ tmp11
,
3435 CONST_BITS
+PASS1_BITS
+3)
3437 outptr
[10] = range_limit
[(int) RIGHT_SHIFT(tmp21
- tmp11
,
3438 CONST_BITS
+PASS1_BITS
+3)
3440 outptr
[2] = range_limit
[(int) RIGHT_SHIFT(tmp22
+ tmp12
,
3441 CONST_BITS
+PASS1_BITS
+3)
3443 outptr
[9] = range_limit
[(int) RIGHT_SHIFT(tmp22
- tmp12
,
3444 CONST_BITS
+PASS1_BITS
+3)
3446 outptr
[3] = range_limit
[(int) RIGHT_SHIFT(tmp23
+ tmp13
,
3447 CONST_BITS
+PASS1_BITS
+3)
3449 outptr
[8] = range_limit
[(int) RIGHT_SHIFT(tmp23
- tmp13
,
3450 CONST_BITS
+PASS1_BITS
+3)
3452 outptr
[4] = range_limit
[(int) RIGHT_SHIFT(tmp24
+ tmp14
,
3453 CONST_BITS
+PASS1_BITS
+3)
3455 outptr
[7] = range_limit
[(int) RIGHT_SHIFT(tmp24
- tmp14
,
3456 CONST_BITS
+PASS1_BITS
+3)
3458 outptr
[5] = range_limit
[(int) RIGHT_SHIFT(tmp25
+ tmp15
,
3459 CONST_BITS
+PASS1_BITS
+3)
3461 outptr
[6] = range_limit
[(int) RIGHT_SHIFT(tmp25
- tmp15
,
3462 CONST_BITS
+PASS1_BITS
+3)
3465 wsptr
+= 8; /* advance pointer to next row */
3471 * Perform dequantization and inverse DCT on one block of coefficients,
3472 * producing a 10x5 output block.
3474 * 5-point IDCT in pass 1 (columns), 10-point in pass 2 (rows).
3478 jpeg_idct_10x5 (j_decompress_ptr cinfo
, jpeg_component_info
* compptr
,
3479 JCOEFPTR coef_block
,
3480 JSAMPARRAY output_buf
, JDIMENSION output_col
)
3482 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
;
3483 INT32 tmp20
, tmp21
, tmp22
, tmp23
, tmp24
;
3484 INT32 z1
, z2
, z3
, z4
;
3486 ISLOW_MULT_TYPE
* quantptr
;
3489 JSAMPLE
*range_limit
= IDCT_range_limit(cinfo
);
3491 int workspace
[8*5]; /* buffers data between passes */
3494 /* Pass 1: process columns from input, store into work array.
3495 * 5-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/10).
3499 quantptr
= (ISLOW_MULT_TYPE
*) compptr
->dct_table
;
3501 for (ctr
= 0; ctr
< 8; ctr
++, inptr
++, quantptr
++, wsptr
++) {
3504 tmp12
= DEQUANTIZE(inptr
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]);
3505 tmp12
<<= CONST_BITS
;
3506 /* Add fudge factor here for final descale. */
3507 tmp12
+= ONE
<< (CONST_BITS
-PASS1_BITS
-1);
3508 tmp13
= DEQUANTIZE(inptr
[DCTSIZE
*2], quantptr
[DCTSIZE
*2]);
3509 tmp14
= DEQUANTIZE(inptr
[DCTSIZE
*4], quantptr
[DCTSIZE
*4]);
3510 z1
= MULTIPLY(tmp13
+ tmp14
, FIX(0.790569415)); /* (c2+c4)/2 */
3511 z2
= MULTIPLY(tmp13
- tmp14
, FIX(0.353553391)); /* (c2-c4)/2 */
3519 z2
= DEQUANTIZE(inptr
[DCTSIZE
*1], quantptr
[DCTSIZE
*1]);
3520 z3
= DEQUANTIZE(inptr
[DCTSIZE
*3], quantptr
[DCTSIZE
*3]);
3522 z1
= MULTIPLY(z2
+ z3
, FIX(0.831253876)); /* c3 */
3523 tmp13
= z1
+ MULTIPLY(z2
, FIX(0.513743148)); /* c1-c3 */
3524 tmp14
= z1
- MULTIPLY(z3
, FIX(2.176250899)); /* c1+c3 */
3526 /* Final output stage */
3528 wsptr
[8*0] = (int) RIGHT_SHIFT(tmp10
+ tmp13
, CONST_BITS
-PASS1_BITS
);
3529 wsptr
[8*4] = (int) RIGHT_SHIFT(tmp10
- tmp13
, CONST_BITS
-PASS1_BITS
);
3530 wsptr
[8*1] = (int) RIGHT_SHIFT(tmp11
+ tmp14
, CONST_BITS
-PASS1_BITS
);
3531 wsptr
[8*3] = (int) RIGHT_SHIFT(tmp11
- tmp14
, CONST_BITS
-PASS1_BITS
);
3532 wsptr
[8*2] = (int) RIGHT_SHIFT(tmp12
, CONST_BITS
-PASS1_BITS
);
3535 /* Pass 2: process 5 rows from work array, store into output array.
3536 * 10-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/20).
3540 for (ctr
= 0; ctr
< 5; ctr
++) {
3541 outptr
= output_buf
[ctr
] + output_col
;
3545 /* Add fudge factor here for final descale. */
3546 z3
= (INT32
) wsptr
[0] + (ONE
<< (PASS1_BITS
+2));
3548 z4
= (INT32
) wsptr
[4];
3549 z1
= MULTIPLY(z4
, FIX(1.144122806)); /* c4 */
3550 z2
= MULTIPLY(z4
, FIX(0.437016024)); /* c8 */
3554 tmp22
= z3
- ((z1
- z2
) << 1); /* c0 = (c4-c8)*2 */
3556 z2
= (INT32
) wsptr
[2];
3557 z3
= (INT32
) wsptr
[6];
3559 z1
= MULTIPLY(z2
+ z3
, FIX(0.831253876)); /* c6 */
3560 tmp12
= z1
+ MULTIPLY(z2
, FIX(0.513743148)); /* c2-c6 */
3561 tmp13
= z1
- MULTIPLY(z3
, FIX(2.176250899)); /* c2+c6 */
3563 tmp20
= tmp10
+ tmp12
;
3564 tmp24
= tmp10
- tmp12
;
3565 tmp21
= tmp11
+ tmp13
;
3566 tmp23
= tmp11
- tmp13
;
3570 z1
= (INT32
) wsptr
[1];
3571 z2
= (INT32
) wsptr
[3];
3572 z3
= (INT32
) wsptr
[5];
3574 z4
= (INT32
) wsptr
[7];
3579 tmp12
= MULTIPLY(tmp13
, FIX(0.309016994)); /* (c3-c7)/2 */
3581 z2
= MULTIPLY(tmp11
, FIX(0.951056516)); /* (c3+c7)/2 */
3584 tmp10
= MULTIPLY(z1
, FIX(1.396802247)) + z2
+ z4
; /* c1 */
3585 tmp14
= MULTIPLY(z1
, FIX(0.221231742)) - z2
+ z4
; /* c9 */
3587 z2
= MULTIPLY(tmp11
, FIX(0.587785252)); /* (c1-c9)/2 */
3588 z4
= z3
- tmp12
- (tmp13
<< (CONST_BITS
- 1));
3590 tmp12
= ((z1
- tmp13
) << CONST_BITS
) - z3
;
3592 tmp11
= MULTIPLY(z1
, FIX(1.260073511)) - z2
- z4
; /* c3 */
3593 tmp13
= MULTIPLY(z1
, FIX(0.642039522)) - z2
+ z4
; /* c7 */
3595 /* Final output stage */
3597 outptr
[0] = range_limit
[(int) RIGHT_SHIFT(tmp20
+ tmp10
,
3598 CONST_BITS
+PASS1_BITS
+3)
3600 outptr
[9] = range_limit
[(int) RIGHT_SHIFT(tmp20
- tmp10
,
3601 CONST_BITS
+PASS1_BITS
+3)
3603 outptr
[1] = range_limit
[(int) RIGHT_SHIFT(tmp21
+ tmp11
,
3604 CONST_BITS
+PASS1_BITS
+3)
3606 outptr
[8] = range_limit
[(int) RIGHT_SHIFT(tmp21
- tmp11
,
3607 CONST_BITS
+PASS1_BITS
+3)
3609 outptr
[2] = range_limit
[(int) RIGHT_SHIFT(tmp22
+ tmp12
,
3610 CONST_BITS
+PASS1_BITS
+3)
3612 outptr
[7] = range_limit
[(int) RIGHT_SHIFT(tmp22
- tmp12
,
3613 CONST_BITS
+PASS1_BITS
+3)
3615 outptr
[3] = range_limit
[(int) RIGHT_SHIFT(tmp23
+ tmp13
,
3616 CONST_BITS
+PASS1_BITS
+3)
3618 outptr
[6] = range_limit
[(int) RIGHT_SHIFT(tmp23
- tmp13
,
3619 CONST_BITS
+PASS1_BITS
+3)
3621 outptr
[4] = range_limit
[(int) RIGHT_SHIFT(tmp24
+ tmp14
,
3622 CONST_BITS
+PASS1_BITS
+3)
3624 outptr
[5] = range_limit
[(int) RIGHT_SHIFT(tmp24
- tmp14
,
3625 CONST_BITS
+PASS1_BITS
+3)
3628 wsptr
+= 8; /* advance pointer to next row */
3634 * Perform dequantization and inverse DCT on one block of coefficients,
3635 * producing a 8x4 output block.
3637 * 4-point IDCT in pass 1 (columns), 8-point in pass 2 (rows).
3641 jpeg_idct_8x4 (j_decompress_ptr cinfo
, jpeg_component_info
* compptr
,
3642 JCOEFPTR coef_block
,
3643 JSAMPARRAY output_buf
, JDIMENSION output_col
)
3645 INT32 tmp0
, tmp1
, tmp2
, tmp3
;
3646 INT32 tmp10
, tmp11
, tmp12
, tmp13
;
3649 ISLOW_MULT_TYPE
* quantptr
;
3652 JSAMPLE
*range_limit
= IDCT_range_limit(cinfo
);
3654 int workspace
[8*4]; /* buffers data between passes */
3657 /* Pass 1: process columns from input, store into work array.
3658 * 4-point IDCT kernel,
3659 * cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point IDCT].
3663 quantptr
= (ISLOW_MULT_TYPE
*) compptr
->dct_table
;
3665 for (ctr
= 0; ctr
< 8; ctr
++, inptr
++, quantptr
++, wsptr
++) {
3668 tmp0
= DEQUANTIZE(inptr
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]);
3669 tmp2
= DEQUANTIZE(inptr
[DCTSIZE
*2], quantptr
[DCTSIZE
*2]);
3671 tmp10
= (tmp0
+ tmp2
) << PASS1_BITS
;
3672 tmp12
= (tmp0
- tmp2
) << PASS1_BITS
;
3675 /* Same rotation as in the even part of the 8x8 LL&M IDCT */
3677 z2
= DEQUANTIZE(inptr
[DCTSIZE
*1], quantptr
[DCTSIZE
*1]);
3678 z3
= DEQUANTIZE(inptr
[DCTSIZE
*3], quantptr
[DCTSIZE
*3]);
3680 z1
= MULTIPLY(z2
+ z3
, FIX_0_541196100
); /* c6 */
3681 /* Add fudge factor here for final descale. */
3682 z1
+= ONE
<< (CONST_BITS
-PASS1_BITS
-1);
3683 tmp0
= RIGHT_SHIFT(z1
+ MULTIPLY(z2
, FIX_0_765366865
), /* c2-c6 */
3684 CONST_BITS
-PASS1_BITS
);
3685 tmp2
= RIGHT_SHIFT(z1
- MULTIPLY(z3
, FIX_1_847759065
), /* c2+c6 */
3686 CONST_BITS
-PASS1_BITS
);
3688 /* Final output stage */
3690 wsptr
[8*0] = (int) (tmp10
+ tmp0
);
3691 wsptr
[8*3] = (int) (tmp10
- tmp0
);
3692 wsptr
[8*1] = (int) (tmp12
+ tmp2
);
3693 wsptr
[8*2] = (int) (tmp12
- tmp2
);
3696 /* Pass 2: process rows from work array, store into output array.
3697 * Note that we must descale the results by a factor of 8 == 2**3,
3698 * and also undo the PASS1_BITS scaling.
3699 * 8-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
3703 for (ctr
= 0; ctr
< 4; ctr
++) {
3704 outptr
= output_buf
[ctr
] + output_col
;
3706 /* Even part: reverse the even part of the forward DCT.
3707 * The rotator is c(-6).
3710 z2
= (INT32
) wsptr
[2];
3711 z3
= (INT32
) wsptr
[6];
3713 z1
= MULTIPLY(z2
+ z3
, FIX_0_541196100
); /* c6 */
3714 tmp2
= z1
+ MULTIPLY(z2
, FIX_0_765366865
); /* c2-c6 */
3715 tmp3
= z1
- MULTIPLY(z3
, FIX_1_847759065
); /* c2+c6 */
3717 /* Add fudge factor here for final descale. */
3718 z2
= (INT32
) wsptr
[0] + (ONE
<< (PASS1_BITS
+2));
3719 z3
= (INT32
) wsptr
[4];
3721 tmp0
= (z2
+ z3
) << CONST_BITS
;
3722 tmp1
= (z2
- z3
) << CONST_BITS
;
3724 tmp10
= tmp0
+ tmp2
;
3725 tmp13
= tmp0
- tmp2
;
3726 tmp11
= tmp1
+ tmp3
;
3727 tmp12
= tmp1
- tmp3
;
3729 /* Odd part per figure 8; the matrix is unitary and hence its
3730 * transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively.
3733 tmp0
= (INT32
) wsptr
[7];
3734 tmp1
= (INT32
) wsptr
[5];
3735 tmp2
= (INT32
) wsptr
[3];
3736 tmp3
= (INT32
) wsptr
[1];
3741 z1
= MULTIPLY(z2
+ z3
, FIX_1_175875602
); /* c3 */
3742 z2
= MULTIPLY(z2
, - FIX_1_961570560
); /* -c3-c5 */
3743 z3
= MULTIPLY(z3
, - FIX_0_390180644
); /* -c3+c5 */
3747 z1
= MULTIPLY(tmp0
+ tmp3
, - FIX_0_899976223
); /* -c3+c7 */
3748 tmp0
= MULTIPLY(tmp0
, FIX_0_298631336
); /* -c1+c3+c5-c7 */
3749 tmp3
= MULTIPLY(tmp3
, FIX_1_501321110
); /* c1+c3-c5-c7 */
3753 z1
= MULTIPLY(tmp1
+ tmp2
, - FIX_2_562915447
); /* -c1-c3 */
3754 tmp1
= MULTIPLY(tmp1
, FIX_2_053119869
); /* c1+c3-c5+c7 */
3755 tmp2
= MULTIPLY(tmp2
, FIX_3_072711026
); /* c1+c3+c5-c7 */
3759 /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
3761 outptr
[0] = range_limit
[(int) RIGHT_SHIFT(tmp10
+ tmp3
,
3762 CONST_BITS
+PASS1_BITS
+3)
3764 outptr
[7] = range_limit
[(int) RIGHT_SHIFT(tmp10
- tmp3
,
3765 CONST_BITS
+PASS1_BITS
+3)
3767 outptr
[1] = range_limit
[(int) RIGHT_SHIFT(tmp11
+ tmp2
,
3768 CONST_BITS
+PASS1_BITS
+3)
3770 outptr
[6] = range_limit
[(int) RIGHT_SHIFT(tmp11
- tmp2
,
3771 CONST_BITS
+PASS1_BITS
+3)
3773 outptr
[2] = range_limit
[(int) RIGHT_SHIFT(tmp12
+ tmp1
,
3774 CONST_BITS
+PASS1_BITS
+3)
3776 outptr
[5] = range_limit
[(int) RIGHT_SHIFT(tmp12
- tmp1
,
3777 CONST_BITS
+PASS1_BITS
+3)
3779 outptr
[3] = range_limit
[(int) RIGHT_SHIFT(tmp13
+ tmp0
,
3780 CONST_BITS
+PASS1_BITS
+3)
3782 outptr
[4] = range_limit
[(int) RIGHT_SHIFT(tmp13
- tmp0
,
3783 CONST_BITS
+PASS1_BITS
+3)
3786 wsptr
+= DCTSIZE
; /* advance pointer to next row */
3792 * Perform dequantization and inverse DCT on one block of coefficients,
3793 * producing a reduced-size 6x3 output block.
3795 * 3-point IDCT in pass 1 (columns), 6-point in pass 2 (rows).
3799 jpeg_idct_6x3 (j_decompress_ptr cinfo
, jpeg_component_info
* compptr
,
3800 JCOEFPTR coef_block
,
3801 JSAMPARRAY output_buf
, JDIMENSION output_col
)
3803 INT32 tmp0
, tmp1
, tmp2
, tmp10
, tmp11
, tmp12
;
3806 ISLOW_MULT_TYPE
* quantptr
;
3809 JSAMPLE
*range_limit
= IDCT_range_limit(cinfo
);
3811 int workspace
[6*3]; /* buffers data between passes */
3814 /* Pass 1: process columns from input, store into work array.
3815 * 3-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/6).
3819 quantptr
= (ISLOW_MULT_TYPE
*) compptr
->dct_table
;
3821 for (ctr
= 0; ctr
< 6; ctr
++, inptr
++, quantptr
++, wsptr
++) {
3824 tmp0
= DEQUANTIZE(inptr
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]);
3825 tmp0
<<= CONST_BITS
;
3826 /* Add fudge factor here for final descale. */
3827 tmp0
+= ONE
<< (CONST_BITS
-PASS1_BITS
-1);
3828 tmp2
= DEQUANTIZE(inptr
[DCTSIZE
*2], quantptr
[DCTSIZE
*2]);
3829 tmp12
= MULTIPLY(tmp2
, FIX(0.707106781)); /* c2 */
3830 tmp10
= tmp0
+ tmp12
;
3831 tmp2
= tmp0
- tmp12
- tmp12
;
3835 tmp12
= DEQUANTIZE(inptr
[DCTSIZE
*1], quantptr
[DCTSIZE
*1]);
3836 tmp0
= MULTIPLY(tmp12
, FIX(1.224744871)); /* c1 */
3838 /* Final output stage */
3840 wsptr
[6*0] = (int) RIGHT_SHIFT(tmp10
+ tmp0
, CONST_BITS
-PASS1_BITS
);
3841 wsptr
[6*2] = (int) RIGHT_SHIFT(tmp10
- tmp0
, CONST_BITS
-PASS1_BITS
);
3842 wsptr
[6*1] = (int) RIGHT_SHIFT(tmp2
, CONST_BITS
-PASS1_BITS
);
3845 /* Pass 2: process 3 rows from work array, store into output array.
3846 * 6-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/12).
3850 for (ctr
= 0; ctr
< 3; ctr
++) {
3851 outptr
= output_buf
[ctr
] + output_col
;
3855 /* Add fudge factor here for final descale. */
3856 tmp0
= (INT32
) wsptr
[0] + (ONE
<< (PASS1_BITS
+2));
3857 tmp0
<<= CONST_BITS
;
3858 tmp2
= (INT32
) wsptr
[4];
3859 tmp10
= MULTIPLY(tmp2
, FIX(0.707106781)); /* c4 */
3860 tmp1
= tmp0
+ tmp10
;
3861 tmp11
= tmp0
- tmp10
- tmp10
;
3862 tmp10
= (INT32
) wsptr
[2];
3863 tmp0
= MULTIPLY(tmp10
, FIX(1.224744871)); /* c2 */
3864 tmp10
= tmp1
+ tmp0
;
3865 tmp12
= tmp1
- tmp0
;
3869 z1
= (INT32
) wsptr
[1];
3870 z2
= (INT32
) wsptr
[3];
3871 z3
= (INT32
) wsptr
[5];
3872 tmp1
= MULTIPLY(z1
+ z3
, FIX(0.366025404)); /* c5 */
3873 tmp0
= tmp1
+ ((z1
+ z2
) << CONST_BITS
);
3874 tmp2
= tmp1
+ ((z3
- z2
) << CONST_BITS
);
3875 tmp1
= (z1
- z2
- z3
) << CONST_BITS
;
3877 /* Final output stage */
3879 outptr
[0] = range_limit
[(int) RIGHT_SHIFT(tmp10
+ tmp0
,
3880 CONST_BITS
+PASS1_BITS
+3)
3882 outptr
[5] = range_limit
[(int) RIGHT_SHIFT(tmp10
- tmp0
,
3883 CONST_BITS
+PASS1_BITS
+3)
3885 outptr
[1] = range_limit
[(int) RIGHT_SHIFT(tmp11
+ tmp1
,
3886 CONST_BITS
+PASS1_BITS
+3)
3888 outptr
[4] = range_limit
[(int) RIGHT_SHIFT(tmp11
- tmp1
,
3889 CONST_BITS
+PASS1_BITS
+3)
3891 outptr
[2] = range_limit
[(int) RIGHT_SHIFT(tmp12
+ tmp2
,
3892 CONST_BITS
+PASS1_BITS
+3)
3894 outptr
[3] = range_limit
[(int) RIGHT_SHIFT(tmp12
- tmp2
,
3895 CONST_BITS
+PASS1_BITS
+3)
3898 wsptr
+= 6; /* advance pointer to next row */
3904 * Perform dequantization and inverse DCT on one block of coefficients,
3905 * producing a 4x2 output block.
3907 * 2-point IDCT in pass 1 (columns), 4-point in pass 2 (rows).
3911 jpeg_idct_4x2 (j_decompress_ptr cinfo
, jpeg_component_info
* compptr
,
3912 JCOEFPTR coef_block
,
3913 JSAMPARRAY output_buf
, JDIMENSION output_col
)
3915 INT32 tmp0
, tmp2
, tmp10
, tmp12
;
3918 ISLOW_MULT_TYPE
* quantptr
;
3921 JSAMPLE
*range_limit
= IDCT_range_limit(cinfo
);
3923 INT32 workspace
[4*2]; /* buffers data between passes */
3926 /* Pass 1: process columns from input, store into work array. */
3929 quantptr
= (ISLOW_MULT_TYPE
*) compptr
->dct_table
;
3931 for (ctr
= 0; ctr
< 4; ctr
++, inptr
++, quantptr
++, wsptr
++) {
3934 tmp10
= DEQUANTIZE(inptr
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]);
3938 tmp0
= DEQUANTIZE(inptr
[DCTSIZE
*1], quantptr
[DCTSIZE
*1]);
3940 /* Final output stage */
3942 wsptr
[4*0] = tmp10
+ tmp0
;
3943 wsptr
[4*1] = tmp10
- tmp0
;
3946 /* Pass 2: process 2 rows from work array, store into output array.
3947 * 4-point IDCT kernel,
3948 * cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point IDCT].
3952 for (ctr
= 0; ctr
< 2; ctr
++) {
3953 outptr
= output_buf
[ctr
] + output_col
;
3957 /* Add fudge factor here for final descale. */
3958 tmp0
= wsptr
[0] + (ONE
<< 2);
3961 tmp10
= (tmp0
+ tmp2
) << CONST_BITS
;
3962 tmp12
= (tmp0
- tmp2
) << CONST_BITS
;
3965 /* Same rotation as in the even part of the 8x8 LL&M IDCT */
3970 z1
= MULTIPLY(z2
+ z3
, FIX_0_541196100
); /* c6 */
3971 tmp0
= z1
+ MULTIPLY(z2
, FIX_0_765366865
); /* c2-c6 */
3972 tmp2
= z1
- MULTIPLY(z3
, FIX_1_847759065
); /* c2+c6 */
3974 /* Final output stage */
3976 outptr
[0] = range_limit
[(int) RIGHT_SHIFT(tmp10
+ tmp0
,
3979 outptr
[3] = range_limit
[(int) RIGHT_SHIFT(tmp10
- tmp0
,
3982 outptr
[1] = range_limit
[(int) RIGHT_SHIFT(tmp12
+ tmp2
,
3985 outptr
[2] = range_limit
[(int) RIGHT_SHIFT(tmp12
- tmp2
,
3989 wsptr
+= 4; /* advance pointer to next row */
3995 * Perform dequantization and inverse DCT on one block of coefficients,
3996 * producing a 2x1 output block.
3998 * 1-point IDCT in pass 1 (columns), 2-point in pass 2 (rows).
4002 jpeg_idct_2x1 (j_decompress_ptr cinfo
, jpeg_component_info
* compptr
,
4003 JCOEFPTR coef_block
,
4004 JSAMPARRAY output_buf
, JDIMENSION output_col
)
4007 ISLOW_MULT_TYPE
* quantptr
;
4009 JSAMPLE
*range_limit
= IDCT_range_limit(cinfo
);
4012 /* Pass 1: empty. */
4014 /* Pass 2: process 1 row from input, store into output array. */
4016 quantptr
= (ISLOW_MULT_TYPE
*) compptr
->dct_table
;
4017 outptr
= output_buf
[0] + output_col
;
4021 tmp0
= DEQUANTIZE(coef_block
[0], quantptr
[0]);
4022 /* Add fudge factor here for final descale. */
4027 tmp1
= DEQUANTIZE(coef_block
[1], quantptr
[1]);
4029 /* Final output stage */
4031 outptr
[0] = range_limit
[(int) RIGHT_SHIFT(tmp0
+ tmp1
, 3) & RANGE_MASK
];
4032 outptr
[1] = range_limit
[(int) RIGHT_SHIFT(tmp0
- tmp1
, 3) & RANGE_MASK
];
4037 * Perform dequantization and inverse DCT on one block of coefficients,
4038 * producing a 8x16 output block.
4040 * 16-point IDCT in pass 1 (columns), 8-point in pass 2 (rows).
4044 jpeg_idct_8x16 (j_decompress_ptr cinfo
, jpeg_component_info
* compptr
,
4045 JCOEFPTR coef_block
,
4046 JSAMPARRAY output_buf
, JDIMENSION output_col
)
4048 INT32 tmp0
, tmp1
, tmp2
, tmp3
, tmp10
, tmp11
, tmp12
, tmp13
;
4049 INT32 tmp20
, tmp21
, tmp22
, tmp23
, tmp24
, tmp25
, tmp26
, tmp27
;
4050 INT32 z1
, z2
, z3
, z4
;
4052 ISLOW_MULT_TYPE
* quantptr
;
4055 JSAMPLE
*range_limit
= IDCT_range_limit(cinfo
);
4057 int workspace
[8*16]; /* buffers data between passes */
4060 /* Pass 1: process columns from input, store into work array.
4061 * 16-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/32).
4065 quantptr
= (ISLOW_MULT_TYPE
*) compptr
->dct_table
;
4067 for (ctr
= 0; ctr
< 8; ctr
++, inptr
++, quantptr
++, wsptr
++) {
4070 tmp0
= DEQUANTIZE(inptr
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]);
4071 tmp0
<<= CONST_BITS
;
4072 /* Add fudge factor here for final descale. */
4073 tmp0
+= ONE
<< (CONST_BITS
-PASS1_BITS
-1);
4075 z1
= DEQUANTIZE(inptr
[DCTSIZE
*4], quantptr
[DCTSIZE
*4]);
4076 tmp1
= MULTIPLY(z1
, FIX(1.306562965)); /* c4[16] = c2[8] */
4077 tmp2
= MULTIPLY(z1
, FIX_0_541196100
); /* c12[16] = c6[8] */
4079 tmp10
= tmp0
+ tmp1
;
4080 tmp11
= tmp0
- tmp1
;
4081 tmp12
= tmp0
+ tmp2
;
4082 tmp13
= tmp0
- tmp2
;
4084 z1
= DEQUANTIZE(inptr
[DCTSIZE
*2], quantptr
[DCTSIZE
*2]);
4085 z2
= DEQUANTIZE(inptr
[DCTSIZE
*6], quantptr
[DCTSIZE
*6]);
4087 z4
= MULTIPLY(z3
, FIX(0.275899379)); /* c14[16] = c7[8] */
4088 z3
= MULTIPLY(z3
, FIX(1.387039845)); /* c2[16] = c1[8] */
4090 tmp0
= z3
+ MULTIPLY(z2
, FIX_2_562915447
); /* (c6+c2)[16] = (c3+c1)[8] */
4091 tmp1
= z4
+ MULTIPLY(z1
, FIX_0_899976223
); /* (c6-c14)[16] = (c3-c7)[8] */
4092 tmp2
= z3
- MULTIPLY(z1
, FIX(0.601344887)); /* (c2-c10)[16] = (c1-c5)[8] */
4093 tmp3
= z4
- MULTIPLY(z2
, FIX(0.509795579)); /* (c10-c14)[16] = (c5-c7)[8] */
4095 tmp20
= tmp10
+ tmp0
;
4096 tmp27
= tmp10
- tmp0
;
4097 tmp21
= tmp12
+ tmp1
;
4098 tmp26
= tmp12
- tmp1
;
4099 tmp22
= tmp13
+ tmp2
;
4100 tmp25
= tmp13
- tmp2
;
4101 tmp23
= tmp11
+ tmp3
;
4102 tmp24
= tmp11
- tmp3
;
4106 z1
= DEQUANTIZE(inptr
[DCTSIZE
*1], quantptr
[DCTSIZE
*1]);
4107 z2
= DEQUANTIZE(inptr
[DCTSIZE
*3], quantptr
[DCTSIZE
*3]);
4108 z3
= DEQUANTIZE(inptr
[DCTSIZE
*5], quantptr
[DCTSIZE
*5]);
4109 z4
= DEQUANTIZE(inptr
[DCTSIZE
*7], quantptr
[DCTSIZE
*7]);
4113 tmp1
= MULTIPLY(z1
+ z2
, FIX(1.353318001)); /* c3 */
4114 tmp2
= MULTIPLY(tmp11
, FIX(1.247225013)); /* c5 */
4115 tmp3
= MULTIPLY(z1
+ z4
, FIX(1.093201867)); /* c7 */
4116 tmp10
= MULTIPLY(z1
- z4
, FIX(0.897167586)); /* c9 */
4117 tmp11
= MULTIPLY(tmp11
, FIX(0.666655658)); /* c11 */
4118 tmp12
= MULTIPLY(z1
- z2
, FIX(0.410524528)); /* c13 */
4119 tmp0
= tmp1
+ tmp2
+ tmp3
-
4120 MULTIPLY(z1
, FIX(2.286341144)); /* c7+c5+c3-c1 */
4121 tmp13
= tmp10
+ tmp11
+ tmp12
-
4122 MULTIPLY(z1
, FIX(1.835730603)); /* c9+c11+c13-c15 */
4123 z1
= MULTIPLY(z2
+ z3
, FIX(0.138617169)); /* c15 */
4124 tmp1
+= z1
+ MULTIPLY(z2
, FIX(0.071888074)); /* c9+c11-c3-c15 */
4125 tmp2
+= z1
- MULTIPLY(z3
, FIX(1.125726048)); /* c5+c7+c15-c3 */
4126 z1
= MULTIPLY(z3
- z2
, FIX(1.407403738)); /* c1 */
4127 tmp11
+= z1
- MULTIPLY(z3
, FIX(0.766367282)); /* c1+c11-c9-c13 */
4128 tmp12
+= z1
+ MULTIPLY(z2
, FIX(1.971951411)); /* c1+c5+c13-c7 */
4130 z1
= MULTIPLY(z2
, - FIX(0.666655658)); /* -c11 */
4132 tmp3
+= z1
+ MULTIPLY(z4
, FIX(1.065388962)); /* c3+c11+c15-c7 */
4133 z2
= MULTIPLY(z2
, - FIX(1.247225013)); /* -c5 */
4134 tmp10
+= z2
+ MULTIPLY(z4
, FIX(3.141271809)); /* c1+c5+c9-c13 */
4136 z2
= MULTIPLY(z3
+ z4
, - FIX(1.353318001)); /* -c3 */
4139 z2
= MULTIPLY(z4
- z3
, FIX(0.410524528)); /* c13 */
4143 /* Final output stage */
4145 wsptr
[8*0] = (int) RIGHT_SHIFT(tmp20
+ tmp0
, CONST_BITS
-PASS1_BITS
);
4146 wsptr
[8*15] = (int) RIGHT_SHIFT(tmp20
- tmp0
, CONST_BITS
-PASS1_BITS
);
4147 wsptr
[8*1] = (int) RIGHT_SHIFT(tmp21
+ tmp1
, CONST_BITS
-PASS1_BITS
);
4148 wsptr
[8*14] = (int) RIGHT_SHIFT(tmp21
- tmp1
, CONST_BITS
-PASS1_BITS
);
4149 wsptr
[8*2] = (int) RIGHT_SHIFT(tmp22
+ tmp2
, CONST_BITS
-PASS1_BITS
);
4150 wsptr
[8*13] = (int) RIGHT_SHIFT(tmp22
- tmp2
, CONST_BITS
-PASS1_BITS
);
4151 wsptr
[8*3] = (int) RIGHT_SHIFT(tmp23
+ tmp3
, CONST_BITS
-PASS1_BITS
);
4152 wsptr
[8*12] = (int) RIGHT_SHIFT(tmp23
- tmp3
, CONST_BITS
-PASS1_BITS
);
4153 wsptr
[8*4] = (int) RIGHT_SHIFT(tmp24
+ tmp10
, CONST_BITS
-PASS1_BITS
);
4154 wsptr
[8*11] = (int) RIGHT_SHIFT(tmp24
- tmp10
, CONST_BITS
-PASS1_BITS
);
4155 wsptr
[8*5] = (int) RIGHT_SHIFT(tmp25
+ tmp11
, CONST_BITS
-PASS1_BITS
);
4156 wsptr
[8*10] = (int) RIGHT_SHIFT(tmp25
- tmp11
, CONST_BITS
-PASS1_BITS
);
4157 wsptr
[8*6] = (int) RIGHT_SHIFT(tmp26
+ tmp12
, CONST_BITS
-PASS1_BITS
);
4158 wsptr
[8*9] = (int) RIGHT_SHIFT(tmp26
- tmp12
, CONST_BITS
-PASS1_BITS
);
4159 wsptr
[8*7] = (int) RIGHT_SHIFT(tmp27
+ tmp13
, CONST_BITS
-PASS1_BITS
);
4160 wsptr
[8*8] = (int) RIGHT_SHIFT(tmp27
- tmp13
, CONST_BITS
-PASS1_BITS
);
4163 /* Pass 2: process rows from work array, store into output array.
4164 * Note that we must descale the results by a factor of 8 == 2**3,
4165 * and also undo the PASS1_BITS scaling.
4166 * 8-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
4170 for (ctr
= 0; ctr
< 16; ctr
++) {
4171 outptr
= output_buf
[ctr
] + output_col
;
4173 /* Even part: reverse the even part of the forward DCT.
4174 * The rotator is c(-6).
4177 z2
= (INT32
) wsptr
[2];
4178 z3
= (INT32
) wsptr
[6];
4180 z1
= MULTIPLY(z2
+ z3
, FIX_0_541196100
); /* c6 */
4181 tmp2
= z1
+ MULTIPLY(z2
, FIX_0_765366865
); /* c2-c6 */
4182 tmp3
= z1
- MULTIPLY(z3
, FIX_1_847759065
); /* c2+c6 */
4184 /* Add fudge factor here for final descale. */
4185 z2
= (INT32
) wsptr
[0] + (ONE
<< (PASS1_BITS
+2));
4186 z3
= (INT32
) wsptr
[4];
4188 tmp0
= (z2
+ z3
) << CONST_BITS
;
4189 tmp1
= (z2
- z3
) << CONST_BITS
;
4191 tmp10
= tmp0
+ tmp2
;
4192 tmp13
= tmp0
- tmp2
;
4193 tmp11
= tmp1
+ tmp3
;
4194 tmp12
= tmp1
- tmp3
;
4196 /* Odd part per figure 8; the matrix is unitary and hence its
4197 * transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively.
4200 tmp0
= (INT32
) wsptr
[7];
4201 tmp1
= (INT32
) wsptr
[5];
4202 tmp2
= (INT32
) wsptr
[3];
4203 tmp3
= (INT32
) wsptr
[1];
4208 z1
= MULTIPLY(z2
+ z3
, FIX_1_175875602
); /* c3 */
4209 z2
= MULTIPLY(z2
, - FIX_1_961570560
); /* -c3-c5 */
4210 z3
= MULTIPLY(z3
, - FIX_0_390180644
); /* -c3+c5 */
4214 z1
= MULTIPLY(tmp0
+ tmp3
, - FIX_0_899976223
); /* -c3+c7 */
4215 tmp0
= MULTIPLY(tmp0
, FIX_0_298631336
); /* -c1+c3+c5-c7 */
4216 tmp3
= MULTIPLY(tmp3
, FIX_1_501321110
); /* c1+c3-c5-c7 */
4220 z1
= MULTIPLY(tmp1
+ tmp2
, - FIX_2_562915447
); /* -c1-c3 */
4221 tmp1
= MULTIPLY(tmp1
, FIX_2_053119869
); /* c1+c3-c5+c7 */
4222 tmp2
= MULTIPLY(tmp2
, FIX_3_072711026
); /* c1+c3+c5-c7 */
4226 /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
4228 outptr
[0] = range_limit
[(int) RIGHT_SHIFT(tmp10
+ tmp3
,
4229 CONST_BITS
+PASS1_BITS
+3)
4231 outptr
[7] = range_limit
[(int) RIGHT_SHIFT(tmp10
- tmp3
,
4232 CONST_BITS
+PASS1_BITS
+3)
4234 outptr
[1] = range_limit
[(int) RIGHT_SHIFT(tmp11
+ tmp2
,
4235 CONST_BITS
+PASS1_BITS
+3)
4237 outptr
[6] = range_limit
[(int) RIGHT_SHIFT(tmp11
- tmp2
,
4238 CONST_BITS
+PASS1_BITS
+3)
4240 outptr
[2] = range_limit
[(int) RIGHT_SHIFT(tmp12
+ tmp1
,
4241 CONST_BITS
+PASS1_BITS
+3)
4243 outptr
[5] = range_limit
[(int) RIGHT_SHIFT(tmp12
- tmp1
,
4244 CONST_BITS
+PASS1_BITS
+3)
4246 outptr
[3] = range_limit
[(int) RIGHT_SHIFT(tmp13
+ tmp0
,
4247 CONST_BITS
+PASS1_BITS
+3)
4249 outptr
[4] = range_limit
[(int) RIGHT_SHIFT(tmp13
- tmp0
,
4250 CONST_BITS
+PASS1_BITS
+3)
4253 wsptr
+= DCTSIZE
; /* advance pointer to next row */
4259 * Perform dequantization and inverse DCT on one block of coefficients,
4260 * producing a 7x14 output block.
4262 * 14-point IDCT in pass 1 (columns), 7-point in pass 2 (rows).
4266 jpeg_idct_7x14 (j_decompress_ptr cinfo
, jpeg_component_info
* compptr
,
4267 JCOEFPTR coef_block
,
4268 JSAMPARRAY output_buf
, JDIMENSION output_col
)
4270 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
, tmp15
, tmp16
;
4271 INT32 tmp20
, tmp21
, tmp22
, tmp23
, tmp24
, tmp25
, tmp26
;
4272 INT32 z1
, z2
, z3
, z4
;
4274 ISLOW_MULT_TYPE
* quantptr
;
4277 JSAMPLE
*range_limit
= IDCT_range_limit(cinfo
);
4279 int workspace
[7*14]; /* buffers data between passes */
4282 /* Pass 1: process columns from input, store into work array.
4283 * 14-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/28).
4287 quantptr
= (ISLOW_MULT_TYPE
*) compptr
->dct_table
;
4289 for (ctr
= 0; ctr
< 7; ctr
++, inptr
++, quantptr
++, wsptr
++) {
4292 z1
= DEQUANTIZE(inptr
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]);
4294 /* Add fudge factor here for final descale. */
4295 z1
+= ONE
<< (CONST_BITS
-PASS1_BITS
-1);
4296 z4
= DEQUANTIZE(inptr
[DCTSIZE
*4], quantptr
[DCTSIZE
*4]);
4297 z2
= MULTIPLY(z4
, FIX(1.274162392)); /* c4 */
4298 z3
= MULTIPLY(z4
, FIX(0.314692123)); /* c12 */
4299 z4
= MULTIPLY(z4
, FIX(0.881747734)); /* c8 */
4305 tmp23
= RIGHT_SHIFT(z1
- ((z2
+ z3
- z4
) << 1), /* c0 = (c4+c12-c8)*2 */
4306 CONST_BITS
-PASS1_BITS
);
4308 z1
= DEQUANTIZE(inptr
[DCTSIZE
*2], quantptr
[DCTSIZE
*2]);
4309 z2
= DEQUANTIZE(inptr
[DCTSIZE
*6], quantptr
[DCTSIZE
*6]);
4311 z3
= MULTIPLY(z1
+ z2
, FIX(1.105676686)); /* c6 */
4313 tmp13
= z3
+ MULTIPLY(z1
, FIX(0.273079590)); /* c2-c6 */
4314 tmp14
= z3
- MULTIPLY(z2
, FIX(1.719280954)); /* c6+c10 */
4315 tmp15
= MULTIPLY(z1
, FIX(0.613604268)) - /* c10 */
4316 MULTIPLY(z2
, FIX(1.378756276)); /* c2 */
4318 tmp20
= tmp10
+ tmp13
;
4319 tmp26
= tmp10
- tmp13
;
4320 tmp21
= tmp11
+ tmp14
;
4321 tmp25
= tmp11
- tmp14
;
4322 tmp22
= tmp12
+ tmp15
;
4323 tmp24
= tmp12
- tmp15
;
4327 z1
= DEQUANTIZE(inptr
[DCTSIZE
*1], quantptr
[DCTSIZE
*1]);
4328 z2
= DEQUANTIZE(inptr
[DCTSIZE
*3], quantptr
[DCTSIZE
*3]);
4329 z3
= DEQUANTIZE(inptr
[DCTSIZE
*5], quantptr
[DCTSIZE
*5]);
4330 z4
= DEQUANTIZE(inptr
[DCTSIZE
*7], quantptr
[DCTSIZE
*7]);
4331 tmp13
= z4
<< CONST_BITS
;
4334 tmp11
= MULTIPLY(z1
+ z2
, FIX(1.334852607)); /* c3 */
4335 tmp12
= MULTIPLY(tmp14
, FIX(1.197448846)); /* c5 */
4336 tmp10
= tmp11
+ tmp12
+ tmp13
- MULTIPLY(z1
, FIX(1.126980169)); /* c3+c5-c1 */
4337 tmp14
= MULTIPLY(tmp14
, FIX(0.752406978)); /* c9 */
4338 tmp16
= tmp14
- MULTIPLY(z1
, FIX(1.061150426)); /* c9+c11-c13 */
4340 tmp15
= MULTIPLY(z1
, FIX(0.467085129)) - tmp13
; /* c11 */
4343 z4
= MULTIPLY(z2
+ z3
, - FIX(0.158341681)) - tmp13
; /* -c13 */
4344 tmp11
+= z4
- MULTIPLY(z2
, FIX(0.424103948)); /* c3-c9-c13 */
4345 tmp12
+= z4
- MULTIPLY(z3
, FIX(2.373959773)); /* c3+c5-c13 */
4346 z4
= MULTIPLY(z3
- z2
, FIX(1.405321284)); /* c1 */
4347 tmp14
+= z4
+ tmp13
- MULTIPLY(z3
, FIX(1.6906431334)); /* c1+c9-c11 */
4348 tmp15
+= z4
+ MULTIPLY(z2
, FIX(0.674957567)); /* c1+c11-c5 */
4350 tmp13
= (z1
- z3
) << PASS1_BITS
;
4352 /* Final output stage */
4354 wsptr
[7*0] = (int) RIGHT_SHIFT(tmp20
+ tmp10
, CONST_BITS
-PASS1_BITS
);
4355 wsptr
[7*13] = (int) RIGHT_SHIFT(tmp20
- tmp10
, CONST_BITS
-PASS1_BITS
);
4356 wsptr
[7*1] = (int) RIGHT_SHIFT(tmp21
+ tmp11
, CONST_BITS
-PASS1_BITS
);
4357 wsptr
[7*12] = (int) RIGHT_SHIFT(tmp21
- tmp11
, CONST_BITS
-PASS1_BITS
);
4358 wsptr
[7*2] = (int) RIGHT_SHIFT(tmp22
+ tmp12
, CONST_BITS
-PASS1_BITS
);
4359 wsptr
[7*11] = (int) RIGHT_SHIFT(tmp22
- tmp12
, CONST_BITS
-PASS1_BITS
);
4360 wsptr
[7*3] = (int) (tmp23
+ tmp13
);
4361 wsptr
[7*10] = (int) (tmp23
- tmp13
);
4362 wsptr
[7*4] = (int) RIGHT_SHIFT(tmp24
+ tmp14
, CONST_BITS
-PASS1_BITS
);
4363 wsptr
[7*9] = (int) RIGHT_SHIFT(tmp24
- tmp14
, CONST_BITS
-PASS1_BITS
);
4364 wsptr
[7*5] = (int) RIGHT_SHIFT(tmp25
+ tmp15
, CONST_BITS
-PASS1_BITS
);
4365 wsptr
[7*8] = (int) RIGHT_SHIFT(tmp25
- tmp15
, CONST_BITS
-PASS1_BITS
);
4366 wsptr
[7*6] = (int) RIGHT_SHIFT(tmp26
+ tmp16
, CONST_BITS
-PASS1_BITS
);
4367 wsptr
[7*7] = (int) RIGHT_SHIFT(tmp26
- tmp16
, CONST_BITS
-PASS1_BITS
);
4370 /* Pass 2: process 14 rows from work array, store into output array.
4371 * 7-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/14).
4375 for (ctr
= 0; ctr
< 14; ctr
++) {
4376 outptr
= output_buf
[ctr
] + output_col
;
4380 /* Add fudge factor here for final descale. */
4381 tmp23
= (INT32
) wsptr
[0] + (ONE
<< (PASS1_BITS
+2));
4382 tmp23
<<= CONST_BITS
;
4384 z1
= (INT32
) wsptr
[2];
4385 z2
= (INT32
) wsptr
[4];
4386 z3
= (INT32
) wsptr
[6];
4388 tmp20
= MULTIPLY(z2
- z3
, FIX(0.881747734)); /* c4 */
4389 tmp22
= MULTIPLY(z1
- z2
, FIX(0.314692123)); /* c6 */
4390 tmp21
= tmp20
+ tmp22
+ tmp23
- MULTIPLY(z2
, FIX(1.841218003)); /* c2+c4-c6 */
4393 tmp10
= MULTIPLY(tmp10
, FIX(1.274162392)) + tmp23
; /* c2 */
4394 tmp20
+= tmp10
- MULTIPLY(z3
, FIX(0.077722536)); /* c2-c4-c6 */
4395 tmp22
+= tmp10
- MULTIPLY(z1
, FIX(2.470602249)); /* c2+c4+c6 */
4396 tmp23
+= MULTIPLY(z2
, FIX(1.414213562)); /* c0 */
4400 z1
= (INT32
) wsptr
[1];
4401 z2
= (INT32
) wsptr
[3];
4402 z3
= (INT32
) wsptr
[5];
4404 tmp11
= MULTIPLY(z1
+ z2
, FIX(0.935414347)); /* (c3+c1-c5)/2 */
4405 tmp12
= MULTIPLY(z1
- z2
, FIX(0.170262339)); /* (c3+c5-c1)/2 */
4406 tmp10
= tmp11
- tmp12
;
4408 tmp12
= MULTIPLY(z2
+ z3
, - FIX(1.378756276)); /* -c1 */
4410 z2
= MULTIPLY(z1
+ z3
, FIX(0.613604268)); /* c5 */
4412 tmp12
+= z2
+ MULTIPLY(z3
, FIX(1.870828693)); /* c3+c1-c5 */
4414 /* Final output stage */
4416 outptr
[0] = range_limit
[(int) RIGHT_SHIFT(tmp20
+ tmp10
,
4417 CONST_BITS
+PASS1_BITS
+3)
4419 outptr
[6] = range_limit
[(int) RIGHT_SHIFT(tmp20
- tmp10
,
4420 CONST_BITS
+PASS1_BITS
+3)
4422 outptr
[1] = range_limit
[(int) RIGHT_SHIFT(tmp21
+ tmp11
,
4423 CONST_BITS
+PASS1_BITS
+3)
4425 outptr
[5] = range_limit
[(int) RIGHT_SHIFT(tmp21
- tmp11
,
4426 CONST_BITS
+PASS1_BITS
+3)
4428 outptr
[2] = range_limit
[(int) RIGHT_SHIFT(tmp22
+ tmp12
,
4429 CONST_BITS
+PASS1_BITS
+3)
4431 outptr
[4] = range_limit
[(int) RIGHT_SHIFT(tmp22
- tmp12
,
4432 CONST_BITS
+PASS1_BITS
+3)
4434 outptr
[3] = range_limit
[(int) RIGHT_SHIFT(tmp23
,
4435 CONST_BITS
+PASS1_BITS
+3)
4438 wsptr
+= 7; /* advance pointer to next row */
4444 * Perform dequantization and inverse DCT on one block of coefficients,
4445 * producing a 6x12 output block.
4447 * 12-point IDCT in pass 1 (columns), 6-point in pass 2 (rows).
4451 jpeg_idct_6x12 (j_decompress_ptr cinfo
, jpeg_component_info
* compptr
,
4452 JCOEFPTR coef_block
,
4453 JSAMPARRAY output_buf
, JDIMENSION output_col
)
4455 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
, tmp15
;
4456 INT32 tmp20
, tmp21
, tmp22
, tmp23
, tmp24
, tmp25
;
4457 INT32 z1
, z2
, z3
, z4
;
4459 ISLOW_MULT_TYPE
* quantptr
;
4462 JSAMPLE
*range_limit
= IDCT_range_limit(cinfo
);
4464 int workspace
[6*12]; /* buffers data between passes */
4467 /* Pass 1: process columns from input, store into work array.
4468 * 12-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/24).
4472 quantptr
= (ISLOW_MULT_TYPE
*) compptr
->dct_table
;
4474 for (ctr
= 0; ctr
< 6; ctr
++, inptr
++, quantptr
++, wsptr
++) {
4477 z3
= DEQUANTIZE(inptr
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]);
4479 /* Add fudge factor here for final descale. */
4480 z3
+= ONE
<< (CONST_BITS
-PASS1_BITS
-1);
4482 z4
= DEQUANTIZE(inptr
[DCTSIZE
*4], quantptr
[DCTSIZE
*4]);
4483 z4
= MULTIPLY(z4
, FIX(1.224744871)); /* c4 */
4488 z1
= DEQUANTIZE(inptr
[DCTSIZE
*2], quantptr
[DCTSIZE
*2]);
4489 z4
= MULTIPLY(z1
, FIX(1.366025404)); /* c2 */
4491 z2
= DEQUANTIZE(inptr
[DCTSIZE
*6], quantptr
[DCTSIZE
*6]);
4501 tmp20
= tmp10
+ tmp12
;
4502 tmp25
= tmp10
- tmp12
;
4504 tmp12
= z4
- z1
- z2
;
4506 tmp22
= tmp11
+ tmp12
;
4507 tmp23
= tmp11
- tmp12
;
4511 z1
= DEQUANTIZE(inptr
[DCTSIZE
*1], quantptr
[DCTSIZE
*1]);
4512 z2
= DEQUANTIZE(inptr
[DCTSIZE
*3], quantptr
[DCTSIZE
*3]);
4513 z3
= DEQUANTIZE(inptr
[DCTSIZE
*5], quantptr
[DCTSIZE
*5]);
4514 z4
= DEQUANTIZE(inptr
[DCTSIZE
*7], quantptr
[DCTSIZE
*7]);
4516 tmp11
= MULTIPLY(z2
, FIX(1.306562965)); /* c3 */
4517 tmp14
= MULTIPLY(z2
, - FIX_0_541196100
); /* -c9 */
4520 tmp15
= MULTIPLY(tmp10
+ z4
, FIX(0.860918669)); /* c7 */
4521 tmp12
= tmp15
+ MULTIPLY(tmp10
, FIX(0.261052384)); /* c5-c7 */
4522 tmp10
= tmp12
+ tmp11
+ MULTIPLY(z1
, FIX(0.280143716)); /* c1-c5 */
4523 tmp13
= MULTIPLY(z3
+ z4
, - FIX(1.045510580)); /* -(c7+c11) */
4524 tmp12
+= tmp13
+ tmp14
- MULTIPLY(z3
, FIX(1.478575242)); /* c1+c5-c7-c11 */
4525 tmp13
+= tmp15
- tmp11
+ MULTIPLY(z4
, FIX(1.586706681)); /* c1+c11 */
4526 tmp15
+= tmp14
- MULTIPLY(z1
, FIX(0.676326758)) - /* c7-c11 */
4527 MULTIPLY(z4
, FIX(1.982889723)); /* c5+c7 */
4531 z3
= MULTIPLY(z1
+ z2
, FIX_0_541196100
); /* c9 */
4532 tmp11
= z3
+ MULTIPLY(z1
, FIX_0_765366865
); /* c3-c9 */
4533 tmp14
= z3
- MULTIPLY(z2
, FIX_1_847759065
); /* c3+c9 */
4535 /* Final output stage */
4537 wsptr
[6*0] = (int) RIGHT_SHIFT(tmp20
+ tmp10
, CONST_BITS
-PASS1_BITS
);
4538 wsptr
[6*11] = (int) RIGHT_SHIFT(tmp20
- tmp10
, CONST_BITS
-PASS1_BITS
);
4539 wsptr
[6*1] = (int) RIGHT_SHIFT(tmp21
+ tmp11
, CONST_BITS
-PASS1_BITS
);
4540 wsptr
[6*10] = (int) RIGHT_SHIFT(tmp21
- tmp11
, CONST_BITS
-PASS1_BITS
);
4541 wsptr
[6*2] = (int) RIGHT_SHIFT(tmp22
+ tmp12
, CONST_BITS
-PASS1_BITS
);
4542 wsptr
[6*9] = (int) RIGHT_SHIFT(tmp22
- tmp12
, CONST_BITS
-PASS1_BITS
);
4543 wsptr
[6*3] = (int) RIGHT_SHIFT(tmp23
+ tmp13
, CONST_BITS
-PASS1_BITS
);
4544 wsptr
[6*8] = (int) RIGHT_SHIFT(tmp23
- tmp13
, CONST_BITS
-PASS1_BITS
);
4545 wsptr
[6*4] = (int) RIGHT_SHIFT(tmp24
+ tmp14
, CONST_BITS
-PASS1_BITS
);
4546 wsptr
[6*7] = (int) RIGHT_SHIFT(tmp24
- tmp14
, CONST_BITS
-PASS1_BITS
);
4547 wsptr
[6*5] = (int) RIGHT_SHIFT(tmp25
+ tmp15
, CONST_BITS
-PASS1_BITS
);
4548 wsptr
[6*6] = (int) RIGHT_SHIFT(tmp25
- tmp15
, CONST_BITS
-PASS1_BITS
);
4551 /* Pass 2: process 12 rows from work array, store into output array.
4552 * 6-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/12).
4556 for (ctr
= 0; ctr
< 12; ctr
++) {
4557 outptr
= output_buf
[ctr
] + output_col
;
4561 /* Add fudge factor here for final descale. */
4562 tmp10
= (INT32
) wsptr
[0] + (ONE
<< (PASS1_BITS
+2));
4563 tmp10
<<= CONST_BITS
;
4564 tmp12
= (INT32
) wsptr
[4];
4565 tmp20
= MULTIPLY(tmp12
, FIX(0.707106781)); /* c4 */
4566 tmp11
= tmp10
+ tmp20
;
4567 tmp21
= tmp10
- tmp20
- tmp20
;
4568 tmp20
= (INT32
) wsptr
[2];
4569 tmp10
= MULTIPLY(tmp20
, FIX(1.224744871)); /* c2 */
4570 tmp20
= tmp11
+ tmp10
;
4571 tmp22
= tmp11
- tmp10
;
4575 z1
= (INT32
) wsptr
[1];
4576 z2
= (INT32
) wsptr
[3];
4577 z3
= (INT32
) wsptr
[5];
4578 tmp11
= MULTIPLY(z1
+ z3
, FIX(0.366025404)); /* c5 */
4579 tmp10
= tmp11
+ ((z1
+ z2
) << CONST_BITS
);
4580 tmp12
= tmp11
+ ((z3
- z2
) << CONST_BITS
);
4581 tmp11
= (z1
- z2
- z3
) << CONST_BITS
;
4583 /* Final output stage */
4585 outptr
[0] = range_limit
[(int) RIGHT_SHIFT(tmp20
+ tmp10
,
4586 CONST_BITS
+PASS1_BITS
+3)
4588 outptr
[5] = range_limit
[(int) RIGHT_SHIFT(tmp20
- tmp10
,
4589 CONST_BITS
+PASS1_BITS
+3)
4591 outptr
[1] = range_limit
[(int) RIGHT_SHIFT(tmp21
+ tmp11
,
4592 CONST_BITS
+PASS1_BITS
+3)
4594 outptr
[4] = range_limit
[(int) RIGHT_SHIFT(tmp21
- tmp11
,
4595 CONST_BITS
+PASS1_BITS
+3)
4597 outptr
[2] = range_limit
[(int) RIGHT_SHIFT(tmp22
+ tmp12
,
4598 CONST_BITS
+PASS1_BITS
+3)
4600 outptr
[3] = range_limit
[(int) RIGHT_SHIFT(tmp22
- tmp12
,
4601 CONST_BITS
+PASS1_BITS
+3)
4604 wsptr
+= 6; /* advance pointer to next row */
4610 * Perform dequantization and inverse DCT on one block of coefficients,
4611 * producing a 5x10 output block.
4613 * 10-point IDCT in pass 1 (columns), 5-point in pass 2 (rows).
4617 jpeg_idct_5x10 (j_decompress_ptr cinfo
, jpeg_component_info
* compptr
,
4618 JCOEFPTR coef_block
,
4619 JSAMPARRAY output_buf
, JDIMENSION output_col
)
4621 INT32 tmp10
, tmp11
, tmp12
, tmp13
, tmp14
;
4622 INT32 tmp20
, tmp21
, tmp22
, tmp23
, tmp24
;
4623 INT32 z1
, z2
, z3
, z4
, z5
;
4625 ISLOW_MULT_TYPE
* quantptr
;
4628 JSAMPLE
*range_limit
= IDCT_range_limit(cinfo
);
4630 int workspace
[5*10]; /* buffers data between passes */
4633 /* Pass 1: process columns from input, store into work array.
4634 * 10-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/20).
4638 quantptr
= (ISLOW_MULT_TYPE
*) compptr
->dct_table
;
4640 for (ctr
= 0; ctr
< 5; ctr
++, inptr
++, quantptr
++, wsptr
++) {
4643 z3
= DEQUANTIZE(inptr
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]);
4645 /* Add fudge factor here for final descale. */
4646 z3
+= ONE
<< (CONST_BITS
-PASS1_BITS
-1);
4647 z4
= DEQUANTIZE(inptr
[DCTSIZE
*4], quantptr
[DCTSIZE
*4]);
4648 z1
= MULTIPLY(z4
, FIX(1.144122806)); /* c4 */
4649 z2
= MULTIPLY(z4
, FIX(0.437016024)); /* c8 */
4653 tmp22
= RIGHT_SHIFT(z3
- ((z1
- z2
) << 1), /* c0 = (c4-c8)*2 */
4654 CONST_BITS
-PASS1_BITS
);
4656 z2
= DEQUANTIZE(inptr
[DCTSIZE
*2], quantptr
[DCTSIZE
*2]);
4657 z3
= DEQUANTIZE(inptr
[DCTSIZE
*6], quantptr
[DCTSIZE
*6]);
4659 z1
= MULTIPLY(z2
+ z3
, FIX(0.831253876)); /* c6 */
4660 tmp12
= z1
+ MULTIPLY(z2
, FIX(0.513743148)); /* c2-c6 */
4661 tmp13
= z1
- MULTIPLY(z3
, FIX(2.176250899)); /* c2+c6 */
4663 tmp20
= tmp10
+ tmp12
;
4664 tmp24
= tmp10
- tmp12
;
4665 tmp21
= tmp11
+ tmp13
;
4666 tmp23
= tmp11
- tmp13
;
4670 z1
= DEQUANTIZE(inptr
[DCTSIZE
*1], quantptr
[DCTSIZE
*1]);
4671 z2
= DEQUANTIZE(inptr
[DCTSIZE
*3], quantptr
[DCTSIZE
*3]);
4672 z3
= DEQUANTIZE(inptr
[DCTSIZE
*5], quantptr
[DCTSIZE
*5]);
4673 z4
= DEQUANTIZE(inptr
[DCTSIZE
*7], quantptr
[DCTSIZE
*7]);
4678 tmp12
= MULTIPLY(tmp13
, FIX(0.309016994)); /* (c3-c7)/2 */
4679 z5
= z3
<< CONST_BITS
;
4681 z2
= MULTIPLY(tmp11
, FIX(0.951056516)); /* (c3+c7)/2 */
4684 tmp10
= MULTIPLY(z1
, FIX(1.396802247)) + z2
+ z4
; /* c1 */
4685 tmp14
= MULTIPLY(z1
, FIX(0.221231742)) - z2
+ z4
; /* c9 */
4687 z2
= MULTIPLY(tmp11
, FIX(0.587785252)); /* (c1-c9)/2 */
4688 z4
= z5
- tmp12
- (tmp13
<< (CONST_BITS
- 1));
4690 tmp12
= (z1
- tmp13
- z3
) << PASS1_BITS
;
4692 tmp11
= MULTIPLY(z1
, FIX(1.260073511)) - z2
- z4
; /* c3 */
4693 tmp13
= MULTIPLY(z1
, FIX(0.642039522)) - z2
+ z4
; /* c7 */
4695 /* Final output stage */
4697 wsptr
[5*0] = (int) RIGHT_SHIFT(tmp20
+ tmp10
, CONST_BITS
-PASS1_BITS
);
4698 wsptr
[5*9] = (int) RIGHT_SHIFT(tmp20
- tmp10
, CONST_BITS
-PASS1_BITS
);
4699 wsptr
[5*1] = (int) RIGHT_SHIFT(tmp21
+ tmp11
, CONST_BITS
-PASS1_BITS
);
4700 wsptr
[5*8] = (int) RIGHT_SHIFT(tmp21
- tmp11
, CONST_BITS
-PASS1_BITS
);
4701 wsptr
[5*2] = (int) (tmp22
+ tmp12
);
4702 wsptr
[5*7] = (int) (tmp22
- tmp12
);
4703 wsptr
[5*3] = (int) RIGHT_SHIFT(tmp23
+ tmp13
, CONST_BITS
-PASS1_BITS
);
4704 wsptr
[5*6] = (int) RIGHT_SHIFT(tmp23
- tmp13
, CONST_BITS
-PASS1_BITS
);
4705 wsptr
[5*4] = (int) RIGHT_SHIFT(tmp24
+ tmp14
, CONST_BITS
-PASS1_BITS
);
4706 wsptr
[5*5] = (int) RIGHT_SHIFT(tmp24
- tmp14
, CONST_BITS
-PASS1_BITS
);
4709 /* Pass 2: process 10 rows from work array, store into output array.
4710 * 5-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/10).
4714 for (ctr
= 0; ctr
< 10; ctr
++) {
4715 outptr
= output_buf
[ctr
] + output_col
;
4719 /* Add fudge factor here for final descale. */
4720 tmp12
= (INT32
) wsptr
[0] + (ONE
<< (PASS1_BITS
+2));
4721 tmp12
<<= CONST_BITS
;
4722 tmp13
= (INT32
) wsptr
[2];
4723 tmp14
= (INT32
) wsptr
[4];
4724 z1
= MULTIPLY(tmp13
+ tmp14
, FIX(0.790569415)); /* (c2+c4)/2 */
4725 z2
= MULTIPLY(tmp13
- tmp14
, FIX(0.353553391)); /* (c2-c4)/2 */
4733 z2
= (INT32
) wsptr
[1];
4734 z3
= (INT32
) wsptr
[3];
4736 z1
= MULTIPLY(z2
+ z3
, FIX(0.831253876)); /* c3 */
4737 tmp13
= z1
+ MULTIPLY(z2
, FIX(0.513743148)); /* c1-c3 */
4738 tmp14
= z1
- MULTIPLY(z3
, FIX(2.176250899)); /* c1+c3 */
4740 /* Final output stage */
4742 outptr
[0] = range_limit
[(int) RIGHT_SHIFT(tmp10
+ tmp13
,
4743 CONST_BITS
+PASS1_BITS
+3)
4745 outptr
[4] = range_limit
[(int) RIGHT_SHIFT(tmp10
- tmp13
,
4746 CONST_BITS
+PASS1_BITS
+3)
4748 outptr
[1] = range_limit
[(int) RIGHT_SHIFT(tmp11
+ tmp14
,
4749 CONST_BITS
+PASS1_BITS
+3)
4751 outptr
[3] = range_limit
[(int) RIGHT_SHIFT(tmp11
- tmp14
,
4752 CONST_BITS
+PASS1_BITS
+3)
4754 outptr
[2] = range_limit
[(int) RIGHT_SHIFT(tmp12
,
4755 CONST_BITS
+PASS1_BITS
+3)
4758 wsptr
+= 5; /* advance pointer to next row */
4764 * Perform dequantization and inverse DCT on one block of coefficients,
4765 * producing a 4x8 output block.
4767 * 8-point IDCT in pass 1 (columns), 4-point in pass 2 (rows).
4771 jpeg_idct_4x8 (j_decompress_ptr cinfo
, jpeg_component_info
* compptr
,
4772 JCOEFPTR coef_block
,
4773 JSAMPARRAY output_buf
, JDIMENSION output_col
)
4775 INT32 tmp0
, tmp1
, tmp2
, tmp3
;
4776 INT32 tmp10
, tmp11
, tmp12
, tmp13
;
4779 ISLOW_MULT_TYPE
* quantptr
;
4782 JSAMPLE
*range_limit
= IDCT_range_limit(cinfo
);
4784 int workspace
[4*8]; /* buffers data between passes */
4787 /* Pass 1: process columns from input, store into work array.
4788 * Note results are scaled up by sqrt(8) compared to a true IDCT;
4789 * furthermore, we scale the results by 2**PASS1_BITS.
4790 * 8-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
4794 quantptr
= (ISLOW_MULT_TYPE
*) compptr
->dct_table
;
4796 for (ctr
= 4; ctr
> 0; ctr
--) {
4797 /* Due to quantization, we will usually find that many of the input
4798 * coefficients are zero, especially the AC terms. We can exploit this
4799 * by short-circuiting the IDCT calculation for any column in which all
4800 * the AC terms are zero. In that case each output is equal to the
4801 * DC coefficient (with scale factor as needed).
4802 * With typical images and quantization tables, half or more of the
4803 * column DCT calculations can be simplified this way.
4806 if (inptr
[DCTSIZE
*1] == 0 && inptr
[DCTSIZE
*2] == 0 &&
4807 inptr
[DCTSIZE
*3] == 0 && inptr
[DCTSIZE
*4] == 0 &&
4808 inptr
[DCTSIZE
*5] == 0 && inptr
[DCTSIZE
*6] == 0 &&
4809 inptr
[DCTSIZE
*7] == 0) {
4810 /* AC terms all zero */
4811 int dcval
= DEQUANTIZE(inptr
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]) << PASS1_BITS
;
4822 inptr
++; /* advance pointers to next column */
4828 /* Even part: reverse the even part of the forward DCT.
4829 * The rotator is c(-6).
4832 z2
= DEQUANTIZE(inptr
[DCTSIZE
*2], quantptr
[DCTSIZE
*2]);
4833 z3
= DEQUANTIZE(inptr
[DCTSIZE
*6], quantptr
[DCTSIZE
*6]);
4835 z1
= MULTIPLY(z2
+ z3
, FIX_0_541196100
); /* c6 */
4836 tmp2
= z1
+ MULTIPLY(z2
, FIX_0_765366865
); /* c2-c6 */
4837 tmp3
= z1
- MULTIPLY(z3
, FIX_1_847759065
); /* c2+c6 */
4839 z2
= DEQUANTIZE(inptr
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]);
4840 z3
= DEQUANTIZE(inptr
[DCTSIZE
*4], quantptr
[DCTSIZE
*4]);
4843 /* Add fudge factor here for final descale. */
4844 z2
+= ONE
<< (CONST_BITS
-PASS1_BITS
-1);
4849 tmp10
= tmp0
+ tmp2
;
4850 tmp13
= tmp0
- tmp2
;
4851 tmp11
= tmp1
+ tmp3
;
4852 tmp12
= tmp1
- tmp3
;
4854 /* Odd part per figure 8; the matrix is unitary and hence its
4855 * transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively.
4858 tmp0
= DEQUANTIZE(inptr
[DCTSIZE
*7], quantptr
[DCTSIZE
*7]);
4859 tmp1
= DEQUANTIZE(inptr
[DCTSIZE
*5], quantptr
[DCTSIZE
*5]);
4860 tmp2
= DEQUANTIZE(inptr
[DCTSIZE
*3], quantptr
[DCTSIZE
*3]);
4861 tmp3
= DEQUANTIZE(inptr
[DCTSIZE
*1], quantptr
[DCTSIZE
*1]);
4866 z1
= MULTIPLY(z2
+ z3
, FIX_1_175875602
); /* c3 */
4867 z2
= MULTIPLY(z2
, - FIX_1_961570560
); /* -c3-c5 */
4868 z3
= MULTIPLY(z3
, - FIX_0_390180644
); /* -c3+c5 */
4872 z1
= MULTIPLY(tmp0
+ tmp3
, - FIX_0_899976223
); /* -c3+c7 */
4873 tmp0
= MULTIPLY(tmp0
, FIX_0_298631336
); /* -c1+c3+c5-c7 */
4874 tmp3
= MULTIPLY(tmp3
, FIX_1_501321110
); /* c1+c3-c5-c7 */
4878 z1
= MULTIPLY(tmp1
+ tmp2
, - FIX_2_562915447
); /* -c1-c3 */
4879 tmp1
= MULTIPLY(tmp1
, FIX_2_053119869
); /* c1+c3-c5+c7 */
4880 tmp2
= MULTIPLY(tmp2
, FIX_3_072711026
); /* c1+c3+c5-c7 */
4884 /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
4886 wsptr
[4*0] = (int) RIGHT_SHIFT(tmp10
+ tmp3
, CONST_BITS
-PASS1_BITS
);
4887 wsptr
[4*7] = (int) RIGHT_SHIFT(tmp10
- tmp3
, CONST_BITS
-PASS1_BITS
);
4888 wsptr
[4*1] = (int) RIGHT_SHIFT(tmp11
+ tmp2
, CONST_BITS
-PASS1_BITS
);
4889 wsptr
[4*6] = (int) RIGHT_SHIFT(tmp11
- tmp2
, CONST_BITS
-PASS1_BITS
);
4890 wsptr
[4*2] = (int) RIGHT_SHIFT(tmp12
+ tmp1
, CONST_BITS
-PASS1_BITS
);
4891 wsptr
[4*5] = (int) RIGHT_SHIFT(tmp12
- tmp1
, CONST_BITS
-PASS1_BITS
);
4892 wsptr
[4*3] = (int) RIGHT_SHIFT(tmp13
+ tmp0
, CONST_BITS
-PASS1_BITS
);
4893 wsptr
[4*4] = (int) RIGHT_SHIFT(tmp13
- tmp0
, CONST_BITS
-PASS1_BITS
);
4895 inptr
++; /* advance pointers to next column */
4900 /* Pass 2: process 8 rows from work array, store into output array.
4901 * 4-point IDCT kernel,
4902 * cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point IDCT].
4906 for (ctr
= 0; ctr
< 8; ctr
++) {
4907 outptr
= output_buf
[ctr
] + output_col
;
4911 /* Add fudge factor here for final descale. */
4912 tmp0
= (INT32
) wsptr
[0] + (ONE
<< (PASS1_BITS
+2));
4913 tmp2
= (INT32
) wsptr
[2];
4915 tmp10
= (tmp0
+ tmp2
) << CONST_BITS
;
4916 tmp12
= (tmp0
- tmp2
) << CONST_BITS
;
4919 /* Same rotation as in the even part of the 8x8 LL&M IDCT */
4921 z2
= (INT32
) wsptr
[1];
4922 z3
= (INT32
) wsptr
[3];
4924 z1
= MULTIPLY(z2
+ z3
, FIX_0_541196100
); /* c6 */
4925 tmp0
= z1
+ MULTIPLY(z2
, FIX_0_765366865
); /* c2-c6 */
4926 tmp2
= z1
- MULTIPLY(z3
, FIX_1_847759065
); /* c2+c6 */
4928 /* Final output stage */
4930 outptr
[0] = range_limit
[(int) RIGHT_SHIFT(tmp10
+ tmp0
,
4931 CONST_BITS
+PASS1_BITS
+3)
4933 outptr
[3] = range_limit
[(int) RIGHT_SHIFT(tmp10
- tmp0
,
4934 CONST_BITS
+PASS1_BITS
+3)
4936 outptr
[1] = range_limit
[(int) RIGHT_SHIFT(tmp12
+ tmp2
,
4937 CONST_BITS
+PASS1_BITS
+3)
4939 outptr
[2] = range_limit
[(int) RIGHT_SHIFT(tmp12
- tmp2
,
4940 CONST_BITS
+PASS1_BITS
+3)
4943 wsptr
+= 4; /* advance pointer to next row */
4949 * Perform dequantization and inverse DCT on one block of coefficients,
4950 * producing a reduced-size 3x6 output block.
4952 * 6-point IDCT in pass 1 (columns), 3-point in pass 2 (rows).
4956 jpeg_idct_3x6 (j_decompress_ptr cinfo
, jpeg_component_info
* compptr
,
4957 JCOEFPTR coef_block
,
4958 JSAMPARRAY output_buf
, JDIMENSION output_col
)
4960 INT32 tmp0
, tmp1
, tmp2
, tmp10
, tmp11
, tmp12
;
4963 ISLOW_MULT_TYPE
* quantptr
;
4966 JSAMPLE
*range_limit
= IDCT_range_limit(cinfo
);
4968 int workspace
[3*6]; /* buffers data between passes */
4971 /* Pass 1: process columns from input, store into work array.
4972 * 6-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/12).
4976 quantptr
= (ISLOW_MULT_TYPE
*) compptr
->dct_table
;
4978 for (ctr
= 0; ctr
< 3; ctr
++, inptr
++, quantptr
++, wsptr
++) {
4981 tmp0
= DEQUANTIZE(inptr
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]);
4982 tmp0
<<= CONST_BITS
;
4983 /* Add fudge factor here for final descale. */
4984 tmp0
+= ONE
<< (CONST_BITS
-PASS1_BITS
-1);
4985 tmp2
= DEQUANTIZE(inptr
[DCTSIZE
*4], quantptr
[DCTSIZE
*4]);
4986 tmp10
= MULTIPLY(tmp2
, FIX(0.707106781)); /* c4 */
4987 tmp1
= tmp0
+ tmp10
;
4988 tmp11
= RIGHT_SHIFT(tmp0
- tmp10
- tmp10
, CONST_BITS
-PASS1_BITS
);
4989 tmp10
= DEQUANTIZE(inptr
[DCTSIZE
*2], quantptr
[DCTSIZE
*2]);
4990 tmp0
= MULTIPLY(tmp10
, FIX(1.224744871)); /* c2 */
4991 tmp10
= tmp1
+ tmp0
;
4992 tmp12
= tmp1
- tmp0
;
4996 z1
= DEQUANTIZE(inptr
[DCTSIZE
*1], quantptr
[DCTSIZE
*1]);
4997 z2
= DEQUANTIZE(inptr
[DCTSIZE
*3], quantptr
[DCTSIZE
*3]);
4998 z3
= DEQUANTIZE(inptr
[DCTSIZE
*5], quantptr
[DCTSIZE
*5]);
4999 tmp1
= MULTIPLY(z1
+ z3
, FIX(0.366025404)); /* c5 */
5000 tmp0
= tmp1
+ ((z1
+ z2
) << CONST_BITS
);
5001 tmp2
= tmp1
+ ((z3
- z2
) << CONST_BITS
);
5002 tmp1
= (z1
- z2
- z3
) << PASS1_BITS
;
5004 /* Final output stage */
5006 wsptr
[3*0] = (int) RIGHT_SHIFT(tmp10
+ tmp0
, CONST_BITS
-PASS1_BITS
);
5007 wsptr
[3*5] = (int) RIGHT_SHIFT(tmp10
- tmp0
, CONST_BITS
-PASS1_BITS
);
5008 wsptr
[3*1] = (int) (tmp11
+ tmp1
);
5009 wsptr
[3*4] = (int) (tmp11
- tmp1
);
5010 wsptr
[3*2] = (int) RIGHT_SHIFT(tmp12
+ tmp2
, CONST_BITS
-PASS1_BITS
);
5011 wsptr
[3*3] = (int) RIGHT_SHIFT(tmp12
- tmp2
, CONST_BITS
-PASS1_BITS
);
5014 /* Pass 2: process 6 rows from work array, store into output array.
5015 * 3-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/6).
5019 for (ctr
= 0; ctr
< 6; ctr
++) {
5020 outptr
= output_buf
[ctr
] + output_col
;
5024 /* Add fudge factor here for final descale. */
5025 tmp0
= (INT32
) wsptr
[0] + (ONE
<< (PASS1_BITS
+2));
5026 tmp0
<<= CONST_BITS
;
5027 tmp2
= (INT32
) wsptr
[2];
5028 tmp12
= MULTIPLY(tmp2
, FIX(0.707106781)); /* c2 */
5029 tmp10
= tmp0
+ tmp12
;
5030 tmp2
= tmp0
- tmp12
- tmp12
;
5034 tmp12
= (INT32
) wsptr
[1];
5035 tmp0
= MULTIPLY(tmp12
, FIX(1.224744871)); /* c1 */
5037 /* Final output stage */
5039 outptr
[0] = range_limit
[(int) RIGHT_SHIFT(tmp10
+ tmp0
,
5040 CONST_BITS
+PASS1_BITS
+3)
5042 outptr
[2] = range_limit
[(int) RIGHT_SHIFT(tmp10
- tmp0
,
5043 CONST_BITS
+PASS1_BITS
+3)
5045 outptr
[1] = range_limit
[(int) RIGHT_SHIFT(tmp2
,
5046 CONST_BITS
+PASS1_BITS
+3)
5049 wsptr
+= 3; /* advance pointer to next row */
5055 * Perform dequantization and inverse DCT on one block of coefficients,
5056 * producing a 2x4 output block.
5058 * 4-point IDCT in pass 1 (columns), 2-point in pass 2 (rows).
5062 jpeg_idct_2x4 (j_decompress_ptr cinfo
, jpeg_component_info
* compptr
,
5063 JCOEFPTR coef_block
,
5064 JSAMPARRAY output_buf
, JDIMENSION output_col
)
5066 INT32 tmp0
, tmp2
, tmp10
, tmp12
;
5069 ISLOW_MULT_TYPE
* quantptr
;
5072 JSAMPLE
*range_limit
= IDCT_range_limit(cinfo
);
5074 INT32 workspace
[2*4]; /* buffers data between passes */
5077 /* Pass 1: process columns from input, store into work array.
5078 * 4-point IDCT kernel,
5079 * cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point IDCT].
5083 quantptr
= (ISLOW_MULT_TYPE
*) compptr
->dct_table
;
5085 for (ctr
= 0; ctr
< 2; ctr
++, inptr
++, quantptr
++, wsptr
++) {
5088 tmp0
= DEQUANTIZE(inptr
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]);
5089 tmp2
= DEQUANTIZE(inptr
[DCTSIZE
*2], quantptr
[DCTSIZE
*2]);
5091 tmp10
= (tmp0
+ tmp2
) << CONST_BITS
;
5092 tmp12
= (tmp0
- tmp2
) << CONST_BITS
;
5095 /* Same rotation as in the even part of the 8x8 LL&M IDCT */
5097 z2
= DEQUANTIZE(inptr
[DCTSIZE
*1], quantptr
[DCTSIZE
*1]);
5098 z3
= DEQUANTIZE(inptr
[DCTSIZE
*3], quantptr
[DCTSIZE
*3]);
5100 z1
= MULTIPLY(z2
+ z3
, FIX_0_541196100
); /* c6 */
5101 tmp0
= z1
+ MULTIPLY(z2
, FIX_0_765366865
); /* c2-c6 */
5102 tmp2
= z1
- MULTIPLY(z3
, FIX_1_847759065
); /* c2+c6 */
5104 /* Final output stage */
5106 wsptr
[2*0] = tmp10
+ tmp0
;
5107 wsptr
[2*3] = tmp10
- tmp0
;
5108 wsptr
[2*1] = tmp12
+ tmp2
;
5109 wsptr
[2*2] = tmp12
- tmp2
;
5112 /* Pass 2: process 4 rows from work array, store into output array. */
5115 for (ctr
= 0; ctr
< 4; ctr
++) {
5116 outptr
= output_buf
[ctr
] + output_col
;
5120 /* Add fudge factor here for final descale. */
5121 tmp10
= wsptr
[0] + (ONE
<< (CONST_BITS
+2));
5127 /* Final output stage */
5129 outptr
[0] = range_limit
[(int) RIGHT_SHIFT(tmp10
+ tmp0
, CONST_BITS
+3)
5131 outptr
[1] = range_limit
[(int) RIGHT_SHIFT(tmp10
- tmp0
, CONST_BITS
+3)
5134 wsptr
+= 2; /* advance pointer to next row */
5140 * Perform dequantization and inverse DCT on one block of coefficients,
5141 * producing a 1x2 output block.
5143 * 2-point IDCT in pass 1 (columns), 1-point in pass 2 (rows).
5147 jpeg_idct_1x2 (j_decompress_ptr cinfo
, jpeg_component_info
* compptr
,
5148 JCOEFPTR coef_block
,
5149 JSAMPARRAY output_buf
, JDIMENSION output_col
)
5152 ISLOW_MULT_TYPE
* quantptr
;
5153 JSAMPLE
*range_limit
= IDCT_range_limit(cinfo
);
5156 /* Process 1 column from input, store into output array. */
5158 quantptr
= (ISLOW_MULT_TYPE
*) compptr
->dct_table
;
5162 tmp0
= DEQUANTIZE(coef_block
[DCTSIZE
*0], quantptr
[DCTSIZE
*0]);
5163 /* Add fudge factor here for final descale. */
5168 tmp1
= DEQUANTIZE(coef_block
[DCTSIZE
*1], quantptr
[DCTSIZE
*1]);
5170 /* Final output stage */
5172 output_buf
[0][output_col
] = range_limit
[(int) RIGHT_SHIFT(tmp0
+ tmp1
, 3)
5174 output_buf
[1][output_col
] = range_limit
[(int) RIGHT_SHIFT(tmp0
- tmp1
, 3)
5178 #endif /* IDCT_SCALING_SUPPORTED */
5179 #endif /* DCT_ISLOW_SUPPORTED */