1 /*
2  * jdcolor.c
3  *
4  * This file was part of the Independent JPEG Group's software:
5  * Copyright (C) 1991-1997, Thomas G. Lane.
6  * Modified 2011 by Guido Vollbeding.
7  * libjpeg-turbo Modifications:
8  * Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
9  * Copyright (C) 2009, 2011-2012, 2014-2015, D. R. Commander.
10  * Copyright (C) 2013, Linaro Limited.
11  * For conditions of distribution and use, see the accompanying README.ijg
12  * file.
13  *
14  * This file contains output colorspace conversion routines.
15  */
16 
17 #define JPEG_INTERNALS
18 #include "jinclude.h"
19 #include "jpeglib.h"
20 #include "jsimd.h"
21 #include "jconfigint.h"
22 
23 
24 /* Private subobject */
25 
26 typedef struct {
27   struct jpeg_color_deconverter pub; /* public fields */
28 
29   /* Private state for YCC->RGB conversion */
30   int *Cr_r_tab;                /* => table for Cr to R conversion */
31   int *Cb_b_tab;                /* => table for Cb to B conversion */
32   JLONG *Cr_g_tab;              /* => table for Cr to G conversion */
33   JLONG *Cb_g_tab;              /* => table for Cb to G conversion */
34 
35   /* Private state for RGB->Y conversion */
36   JLONG *rgb_y_tab;             /* => table for RGB to Y conversion */
37 } my_color_deconverter;
38 
39 typedef my_color_deconverter *my_cconvert_ptr;
40 
41 
42 /**************** YCbCr -> RGB conversion: most common case **************/
43 /****************   RGB -> Y   conversion: less common case **************/
44 
45 /*
46  * YCbCr is defined per CCIR 601-1, except that Cb and Cr are
47  * normalized to the range 0..MAXJSAMPLE rather than -0.5 .. 0.5.
48  * The conversion equations to be implemented are therefore
49  *
50  *      R = Y                + 1.40200 * Cr
51  *      G = Y - 0.34414 * Cb - 0.71414 * Cr
52  *      B = Y + 1.77200 * Cb
53  *
54  *      Y = 0.29900 * R + 0.58700 * G + 0.11400 * B
55  *
56  * where Cb and Cr represent the incoming values less CENTERJSAMPLE.
57  * (These numbers are derived from TIFF 6.0 section 21, dated 3-June-92.)
58  *
59  * To avoid floating-point arithmetic, we represent the fractional constants
60  * as integers scaled up by 2^16 (about 4 digits precision); we have to divide
61  * the products by 2^16, with appropriate rounding, to get the correct answer.
62  * Notice that Y, being an integral input, does not contribute any fraction
63  * so it need not participate in the rounding.
64  *
65  * For even more speed, we avoid doing any multiplications in the inner loop
66  * by precalculating the constants times Cb and Cr for all possible values.
67  * For 8-bit JSAMPLEs this is very reasonable (only 256 entries per table);
68  * for 12-bit samples it is still acceptable.  It's not very reasonable for
69  * 16-bit samples, but if you want lossless storage you shouldn't be changing
70  * colorspace anyway.
71  * The Cr=>R and Cb=>B values can be rounded to integers in advance; the
72  * values for the G calculation are left scaled up, since we must add them
73  * together before rounding.
74  */
75 
76 #define SCALEBITS       16      /* speediest right-shift on some machines */
77 #define ONE_HALF        ((JLONG)1 << (SCALEBITS - 1))
78 #define FIX(x)          ((JLONG)((x) * (1L << SCALEBITS) + 0.5))
79 
80 /* We allocate one big table for RGB->Y conversion and divide it up into
81  * three parts, instead of doing three alloc_small requests.  This lets us
82  * use a single table base address, which can be held in a register in the
83  * inner loops on many machines (more than can hold all three addresses,
84  * anyway).
85  */
86 
87 #define R_Y_OFF         0                       /* offset to R => Y section */
88 #define G_Y_OFF         (1 * (MAXJSAMPLE + 1))  /* offset to G => Y section */
89 #define B_Y_OFF         (2 * (MAXJSAMPLE + 1))  /* etc. */
90 #define TABLE_SIZE      (3 * (MAXJSAMPLE + 1))
91 
92 
93 /* Include inline routines for colorspace extensions */
94 
95 #include "jdcolext.c"
96 #undef RGB_RED
97 #undef RGB_GREEN
98 #undef RGB_BLUE
99 #undef RGB_PIXELSIZE
100 
101 #define RGB_RED  EXT_RGB_RED
102 #define RGB_GREEN  EXT_RGB_GREEN
103 #define RGB_BLUE  EXT_RGB_BLUE
104 #define RGB_PIXELSIZE  EXT_RGB_PIXELSIZE
105 #define ycc_rgb_convert_internal  ycc_extrgb_convert_internal
106 #define gray_rgb_convert_internal  gray_extrgb_convert_internal
107 #define rgb_rgb_convert_internal  rgb_extrgb_convert_internal
108 #include "jdcolext.c"
109 #undef RGB_RED
110 #undef RGB_GREEN
111 #undef RGB_BLUE
112 #undef RGB_PIXELSIZE
113 #undef ycc_rgb_convert_internal
114 #undef gray_rgb_convert_internal
115 #undef rgb_rgb_convert_internal
116 
117 #define RGB_RED  EXT_RGBX_RED
118 #define RGB_GREEN  EXT_RGBX_GREEN
119 #define RGB_BLUE  EXT_RGBX_BLUE
120 #define RGB_ALPHA  3
121 #define RGB_PIXELSIZE  EXT_RGBX_PIXELSIZE
122 #define ycc_rgb_convert_internal  ycc_extrgbx_convert_internal
123 #define gray_rgb_convert_internal  gray_extrgbx_convert_internal
124 #define rgb_rgb_convert_internal  rgb_extrgbx_convert_internal
125 #include "jdcolext.c"
126 #undef RGB_RED
127 #undef RGB_GREEN
128 #undef RGB_BLUE
129 #undef RGB_ALPHA
130 #undef RGB_PIXELSIZE
131 #undef ycc_rgb_convert_internal
132 #undef gray_rgb_convert_internal
133 #undef rgb_rgb_convert_internal
134 
135 #define RGB_RED  EXT_BGR_RED
136 #define RGB_GREEN  EXT_BGR_GREEN
137 #define RGB_BLUE  EXT_BGR_BLUE
138 #define RGB_PIXELSIZE  EXT_BGR_PIXELSIZE
139 #define ycc_rgb_convert_internal  ycc_extbgr_convert_internal
140 #define gray_rgb_convert_internal  gray_extbgr_convert_internal
141 #define rgb_rgb_convert_internal  rgb_extbgr_convert_internal
142 #include "jdcolext.c"
143 #undef RGB_RED
144 #undef RGB_GREEN
145 #undef RGB_BLUE
146 #undef RGB_PIXELSIZE
147 #undef ycc_rgb_convert_internal
148 #undef gray_rgb_convert_internal
149 #undef rgb_rgb_convert_internal
150 
151 #define RGB_RED  EXT_BGRX_RED
152 #define RGB_GREEN  EXT_BGRX_GREEN
153 #define RGB_BLUE  EXT_BGRX_BLUE
154 #define RGB_ALPHA  3
155 #define RGB_PIXELSIZE  EXT_BGRX_PIXELSIZE
156 #define ycc_rgb_convert_internal  ycc_extbgrx_convert_internal
157 #define gray_rgb_convert_internal  gray_extbgrx_convert_internal
158 #define rgb_rgb_convert_internal  rgb_extbgrx_convert_internal
159 #include "jdcolext.c"
160 #undef RGB_RED
161 #undef RGB_GREEN
162 #undef RGB_BLUE
163 #undef RGB_ALPHA
164 #undef RGB_PIXELSIZE
165 #undef ycc_rgb_convert_internal
166 #undef gray_rgb_convert_internal
167 #undef rgb_rgb_convert_internal
168 
169 #define RGB_RED  EXT_XBGR_RED
170 #define RGB_GREEN  EXT_XBGR_GREEN
171 #define RGB_BLUE  EXT_XBGR_BLUE
172 #define RGB_ALPHA  0
173 #define RGB_PIXELSIZE  EXT_XBGR_PIXELSIZE
174 #define ycc_rgb_convert_internal  ycc_extxbgr_convert_internal
175 #define gray_rgb_convert_internal  gray_extxbgr_convert_internal
176 #define rgb_rgb_convert_internal  rgb_extxbgr_convert_internal
177 #include "jdcolext.c"
178 #undef RGB_RED
179 #undef RGB_GREEN
180 #undef RGB_BLUE
181 #undef RGB_ALPHA
182 #undef RGB_PIXELSIZE
183 #undef ycc_rgb_convert_internal
184 #undef gray_rgb_convert_internal
185 #undef rgb_rgb_convert_internal
186 
187 #define RGB_RED  EXT_XRGB_RED
188 #define RGB_GREEN  EXT_XRGB_GREEN
189 #define RGB_BLUE  EXT_XRGB_BLUE
190 #define RGB_ALPHA  0
191 #define RGB_PIXELSIZE  EXT_XRGB_PIXELSIZE
192 #define ycc_rgb_convert_internal  ycc_extxrgb_convert_internal
193 #define gray_rgb_convert_internal  gray_extxrgb_convert_internal
194 #define rgb_rgb_convert_internal  rgb_extxrgb_convert_internal
195 #include "jdcolext.c"
196 #undef RGB_RED
197 #undef RGB_GREEN
198 #undef RGB_BLUE
199 #undef RGB_ALPHA
200 #undef RGB_PIXELSIZE
201 #undef ycc_rgb_convert_internal
202 #undef gray_rgb_convert_internal
203 #undef rgb_rgb_convert_internal
204 
205 
206 /*
207  * Initialize tables for YCC->RGB colorspace conversion.
208  */
209 
210 LOCAL(void)
build_ycc_rgb_table(j_decompress_ptr cinfo)211 build_ycc_rgb_table(j_decompress_ptr cinfo)
212 {
213   my_cconvert_ptr cconvert = (my_cconvert_ptr)cinfo->cconvert;
214   int i;
215   JLONG x;
216   SHIFT_TEMPS
217 
218   cconvert->Cr_r_tab = (int *)
219     (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
220                                 (MAXJSAMPLE + 1) * sizeof(int));
221   cconvert->Cb_b_tab = (int *)
222     (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
223                                 (MAXJSAMPLE + 1) * sizeof(int));
224   cconvert->Cr_g_tab = (JLONG *)
225     (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
226                                 (MAXJSAMPLE + 1) * sizeof(JLONG));
227   cconvert->Cb_g_tab = (JLONG *)
228     (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
229                                 (MAXJSAMPLE + 1) * sizeof(JLONG));
230 
231   for (i = 0, x = -CENTERJSAMPLE; i <= MAXJSAMPLE; i++, x++) {
232     /* i is the actual input pixel value, in the range 0..MAXJSAMPLE */
233     /* The Cb or Cr value we are thinking of is x = i - CENTERJSAMPLE */
234     /* Cr=>R value is nearest int to 1.40200 * x */
235     cconvert->Cr_r_tab[i] = (int)
236                     RIGHT_SHIFT(FIX(1.40200) * x + ONE_HALF, SCALEBITS);
237     /* Cb=>B value is nearest int to 1.77200 * x */
238     cconvert->Cb_b_tab[i] = (int)
239                     RIGHT_SHIFT(FIX(1.77200) * x + ONE_HALF, SCALEBITS);
240     /* Cr=>G value is scaled-up -0.71414 * x */
241     cconvert->Cr_g_tab[i] = (-FIX(0.71414)) * x;
242     /* Cb=>G value is scaled-up -0.34414 * x */
243     /* We also add in ONE_HALF so that need not do it in inner loop */
244     cconvert->Cb_g_tab[i] = (-FIX(0.34414)) * x + ONE_HALF;
245   }
246 }
247 
248 
249 /*
250  * Convert some rows of samples to the output colorspace.
251  */
252 
253 METHODDEF(void)
ycc_rgb_convert(j_decompress_ptr cinfo,JSAMPIMAGE input_buf,JDIMENSION input_row,JSAMPARRAY output_buf,int num_rows)254 ycc_rgb_convert(j_decompress_ptr cinfo, JSAMPIMAGE input_buf,
255                 JDIMENSION input_row, JSAMPARRAY output_buf, int num_rows)
256 {
257   switch (cinfo->out_color_space) {
258   case JCS_EXT_RGB:
259     ycc_extrgb_convert_internal(cinfo, input_buf, input_row, output_buf,
260                                 num_rows);
261     break;
262   case JCS_EXT_RGBX:
263   case JCS_EXT_RGBA:
264     ycc_extrgbx_convert_internal(cinfo, input_buf, input_row, output_buf,
265                                  num_rows);
266     break;
267   case JCS_EXT_BGR:
268     ycc_extbgr_convert_internal(cinfo, input_buf, input_row, output_buf,
269                                 num_rows);
270     break;
271   case JCS_EXT_BGRX:
272   case JCS_EXT_BGRA:
273     ycc_extbgrx_convert_internal(cinfo, input_buf, input_row, output_buf,
274                                  num_rows);
275     break;
276   case JCS_EXT_XBGR:
277   case JCS_EXT_ABGR:
278     ycc_extxbgr_convert_internal(cinfo, input_buf, input_row, output_buf,
279                                  num_rows);
280     break;
281   case JCS_EXT_XRGB:
282   case JCS_EXT_ARGB:
283     ycc_extxrgb_convert_internal(cinfo, input_buf, input_row, output_buf,
284                                  num_rows);
285     break;
286   default:
287     ycc_rgb_convert_internal(cinfo, input_buf, input_row, output_buf,
288                              num_rows);
289     break;
290   }
291 }
292 
293 
294 /**************** Cases other than YCbCr -> RGB **************/
295 
296 
297 /*
298  * Initialize for RGB->grayscale colorspace conversion.
299  */
300 
301 LOCAL(void)
build_rgb_y_table(j_decompress_ptr cinfo)302 build_rgb_y_table(j_decompress_ptr cinfo)
303 {
304   my_cconvert_ptr cconvert = (my_cconvert_ptr)cinfo->cconvert;
305   JLONG *rgb_y_tab;
306   JLONG i;
307 
308   /* Allocate and fill in the conversion tables. */
309   cconvert->rgb_y_tab = rgb_y_tab = (JLONG *)
310     (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
311                                 (TABLE_SIZE * sizeof(JLONG)));
312 
313   for (i = 0; i <= MAXJSAMPLE; i++) {
314     rgb_y_tab[i + R_Y_OFF] = FIX(0.29900) * i;
315     rgb_y_tab[i + G_Y_OFF] = FIX(0.58700) * i;
316     rgb_y_tab[i + B_Y_OFF] = FIX(0.11400) * i + ONE_HALF;
317   }
318 }
319 
320 
321 /*
322  * Convert RGB to grayscale.
323  */
324 
325 METHODDEF(void)
rgb_gray_convert(j_decompress_ptr cinfo,JSAMPIMAGE input_buf,JDIMENSION input_row,JSAMPARRAY output_buf,int num_rows)326 rgb_gray_convert(j_decompress_ptr cinfo, JSAMPIMAGE input_buf,
327                  JDIMENSION input_row, JSAMPARRAY output_buf, int num_rows)
328 {
329   my_cconvert_ptr cconvert = (my_cconvert_ptr)cinfo->cconvert;
330   register int r, g, b;
331   register JLONG *ctab = cconvert->rgb_y_tab;
332   register JSAMPROW outptr;
333   register JSAMPROW inptr0, inptr1, inptr2;
334   register JDIMENSION col;
335   JDIMENSION num_cols = cinfo->output_width;
336 
337   while (--num_rows >= 0) {
338     inptr0 = input_buf[0][input_row];
339     inptr1 = input_buf[1][input_row];
340     inptr2 = input_buf[2][input_row];
341     input_row++;
342     outptr = *output_buf++;
343     for (col = 0; col < num_cols; col++) {
344       r = GETJSAMPLE(inptr0[col]);
345       g = GETJSAMPLE(inptr1[col]);
346       b = GETJSAMPLE(inptr2[col]);
347       /* Y */
348       outptr[col] = (JSAMPLE)((ctab[r + R_Y_OFF] + ctab[g + G_Y_OFF] +
349                                ctab[b + B_Y_OFF]) >> SCALEBITS);
350     }
351   }
352 }
353 
354 
355 /*
356  * Color conversion for no colorspace change: just copy the data,
357  * converting from separate-planes to interleaved representation.
358  */
359 
360 METHODDEF(void)
null_convert(j_decompress_ptr cinfo,JSAMPIMAGE input_buf,JDIMENSION input_row,JSAMPARRAY output_buf,int num_rows)361 null_convert(j_decompress_ptr cinfo, JSAMPIMAGE input_buf,
362              JDIMENSION input_row, JSAMPARRAY output_buf, int num_rows)
363 {
364   register JSAMPROW inptr, inptr0, inptr1, inptr2, inptr3, outptr;
365   register JDIMENSION col;
366   register int num_components = cinfo->num_components;
367   JDIMENSION num_cols = cinfo->output_width;
368   int ci;
369 
370   if (num_components == 3) {
371     while (--num_rows >= 0) {
372       inptr0 = input_buf[0][input_row];
373       inptr1 = input_buf[1][input_row];
374       inptr2 = input_buf[2][input_row];
375       input_row++;
376       outptr = *output_buf++;
377       for (col = 0; col < num_cols; col++) {
378         *outptr++ = inptr0[col];
379         *outptr++ = inptr1[col];
380         *outptr++ = inptr2[col];
381       }
382     }
383   } else if (num_components == 4) {
384     while (--num_rows >= 0) {
385       inptr0 = input_buf[0][input_row];
386       inptr1 = input_buf[1][input_row];
387       inptr2 = input_buf[2][input_row];
388       inptr3 = input_buf[3][input_row];
389       input_row++;
390       outptr = *output_buf++;
391       for (col = 0; col < num_cols; col++) {
392         *outptr++ = inptr0[col];
393         *outptr++ = inptr1[col];
394         *outptr++ = inptr2[col];
395         *outptr++ = inptr3[col];
396       }
397     }
398   } else {
399     while (--num_rows >= 0) {
400       for (ci = 0; ci < num_components; ci++) {
401         inptr = input_buf[ci][input_row];
402         outptr = *output_buf;
403         for (col = 0; col < num_cols; col++) {
404           outptr[ci] = inptr[col];
405           outptr += num_components;
406         }
407       }
408       output_buf++;
409       input_row++;
410     }
411   }
412 }
413 
414 
415 /*
416  * Color conversion for grayscale: just copy the data.
417  * This also works for YCbCr -> grayscale conversion, in which
418  * we just copy the Y (luminance) component and ignore chrominance.
419  */
420 
421 METHODDEF(void)
grayscale_convert(j_decompress_ptr cinfo,JSAMPIMAGE input_buf,JDIMENSION input_row,JSAMPARRAY output_buf,int num_rows)422 grayscale_convert(j_decompress_ptr cinfo, JSAMPIMAGE input_buf,
423                   JDIMENSION input_row, JSAMPARRAY output_buf, int num_rows)
424 {
425   jcopy_sample_rows(input_buf[0], (int)input_row, output_buf, 0, num_rows,
426                     cinfo->output_width);
427 }
428 
429 
430 /*
431  * Convert grayscale to RGB
432  */
433 
434 METHODDEF(void)
gray_rgb_convert(j_decompress_ptr cinfo,JSAMPIMAGE input_buf,JDIMENSION input_row,JSAMPARRAY output_buf,int num_rows)435 gray_rgb_convert(j_decompress_ptr cinfo, JSAMPIMAGE input_buf,
436                  JDIMENSION input_row, JSAMPARRAY output_buf, int num_rows)
437 {
438   switch (cinfo->out_color_space) {
439   case JCS_EXT_RGB:
440     gray_extrgb_convert_internal(cinfo, input_buf, input_row, output_buf,
441                                  num_rows);
442     break;
443   case JCS_EXT_RGBX:
444   case JCS_EXT_RGBA:
445     gray_extrgbx_convert_internal(cinfo, input_buf, input_row, output_buf,
446                                   num_rows);
447     break;
448   case JCS_EXT_BGR:
449     gray_extbgr_convert_internal(cinfo, input_buf, input_row, output_buf,
450                                  num_rows);
451     break;
452   case JCS_EXT_BGRX:
453   case JCS_EXT_BGRA:
454     gray_extbgrx_convert_internal(cinfo, input_buf, input_row, output_buf,
455                                   num_rows);
456     break;
457   case JCS_EXT_XBGR:
458   case JCS_EXT_ABGR:
459     gray_extxbgr_convert_internal(cinfo, input_buf, input_row, output_buf,
460                                   num_rows);
461     break;
462   case JCS_EXT_XRGB:
463   case JCS_EXT_ARGB:
464     gray_extxrgb_convert_internal(cinfo, input_buf, input_row, output_buf,
465                                   num_rows);
466     break;
467   default:
468     gray_rgb_convert_internal(cinfo, input_buf, input_row, output_buf,
469                               num_rows);
470     break;
471   }
472 }
473 
474 
475 /*
476  * Convert plain RGB to extended RGB
477  */
478 
479 METHODDEF(void)
rgb_rgb_convert(j_decompress_ptr cinfo,JSAMPIMAGE input_buf,JDIMENSION input_row,JSAMPARRAY output_buf,int num_rows)480 rgb_rgb_convert(j_decompress_ptr cinfo, JSAMPIMAGE input_buf,
481                 JDIMENSION input_row, JSAMPARRAY output_buf, int num_rows)
482 {
483   switch (cinfo->out_color_space) {
484   case JCS_EXT_RGB:
485     rgb_extrgb_convert_internal(cinfo, input_buf, input_row, output_buf,
486                                 num_rows);
487     break;
488   case JCS_EXT_RGBX:
489   case JCS_EXT_RGBA:
490     rgb_extrgbx_convert_internal(cinfo, input_buf, input_row, output_buf,
491                                  num_rows);
492     break;
493   case JCS_EXT_BGR:
494     rgb_extbgr_convert_internal(cinfo, input_buf, input_row, output_buf,
495                                 num_rows);
496     break;
497   case JCS_EXT_BGRX:
498   case JCS_EXT_BGRA:
499     rgb_extbgrx_convert_internal(cinfo, input_buf, input_row, output_buf,
500                                  num_rows);
501     break;
502   case JCS_EXT_XBGR:
503   case JCS_EXT_ABGR:
504     rgb_extxbgr_convert_internal(cinfo, input_buf, input_row, output_buf,
505                                  num_rows);
506     break;
507   case JCS_EXT_XRGB:
508   case JCS_EXT_ARGB:
509     rgb_extxrgb_convert_internal(cinfo, input_buf, input_row, output_buf,
510                                  num_rows);
511     break;
512   default:
513     rgb_rgb_convert_internal(cinfo, input_buf, input_row, output_buf,
514                              num_rows);
515     break;
516   }
517 }
518 
519 
520 /*
521  * Adobe-style YCCK->CMYK conversion.
522  * We convert YCbCr to R=1-C, G=1-M, and B=1-Y using the same
523  * conversion as above, while passing K (black) unchanged.
524  * We assume build_ycc_rgb_table has been called.
525  */
526 
527 METHODDEF(void)
ycck_cmyk_convert(j_decompress_ptr cinfo,JSAMPIMAGE input_buf,JDIMENSION input_row,JSAMPARRAY output_buf,int num_rows)528 ycck_cmyk_convert(j_decompress_ptr cinfo, JSAMPIMAGE input_buf,
529                   JDIMENSION input_row, JSAMPARRAY output_buf, int num_rows)
530 {
531   my_cconvert_ptr cconvert = (my_cconvert_ptr)cinfo->cconvert;
532   register int y, cb, cr;
533   register JSAMPROW outptr;
534   register JSAMPROW inptr0, inptr1, inptr2, inptr3;
535   register JDIMENSION col;
536   JDIMENSION num_cols = cinfo->output_width;
537   /* copy these pointers into registers if possible */
538   register JSAMPLE *range_limit = cinfo->sample_range_limit;
539   register int *Crrtab = cconvert->Cr_r_tab;
540   register int *Cbbtab = cconvert->Cb_b_tab;
541   register JLONG *Crgtab = cconvert->Cr_g_tab;
542   register JLONG *Cbgtab = cconvert->Cb_g_tab;
543   SHIFT_TEMPS
544 
545   while (--num_rows >= 0) {
546     inptr0 = input_buf[0][input_row];
547     inptr1 = input_buf[1][input_row];
548     inptr2 = input_buf[2][input_row];
549     inptr3 = input_buf[3][input_row];
550     input_row++;
551     outptr = *output_buf++;
552     for (col = 0; col < num_cols; col++) {
553       y  = GETJSAMPLE(inptr0[col]);
554       cb = GETJSAMPLE(inptr1[col]);
555       cr = GETJSAMPLE(inptr2[col]);
556       /* Range-limiting is essential due to noise introduced by DCT losses. */
557       outptr[0] = range_limit[MAXJSAMPLE - (y + Crrtab[cr])];   /* red */
558       outptr[1] = range_limit[MAXJSAMPLE - (y +                 /* green */
559                               ((int)RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr],
560                                                  SCALEBITS)))];
561       outptr[2] = range_limit[MAXJSAMPLE - (y + Cbbtab[cb])];   /* blue */
562       /* K passes through unchanged */
563       outptr[3] = inptr3[col];  /* don't need GETJSAMPLE here */
564       outptr += 4;
565     }
566   }
567 }
568 
569 
570 /*
571  * RGB565 conversion
572  */
573 
574 #define PACK_SHORT_565_LE(r, g, b)  ((((r) << 8) & 0xF800) | \
575                                      (((g) << 3) & 0x7E0) | ((b) >> 3))
576 #define PACK_SHORT_565_BE(r, g, b)  (((r) & 0xF8) | ((g) >> 5) | \
577                                      (((g) << 11) & 0xE000) | \
578                                      (((b) << 5) & 0x1F00))
579 
580 #define PACK_TWO_PIXELS_LE(l, r)    ((r << 16) | l)
581 #define PACK_TWO_PIXELS_BE(l, r)    ((l << 16) | r)
582 
583 #define PACK_NEED_ALIGNMENT(ptr)    (((size_t)(ptr)) & 3)
584 
585 #define WRITE_TWO_ALIGNED_PIXELS(addr, pixels)  ((*(int *)(addr)) = pixels)
586 
587 #define DITHER_565_R(r, dither)  ((r) + ((dither) & 0xFF))
588 #define DITHER_565_G(g, dither)  ((g) + (((dither) & 0xFF) >> 1))
589 #define DITHER_565_B(b, dither)  ((b) + ((dither) & 0xFF))
590 
591 
592 /* Declarations for ordered dithering
593  *
594  * We use a 4x4 ordered dither array packed into 32 bits.  This array is
595  * sufficient for dithering RGB888 to RGB565.
596  */
597 
598 #define DITHER_MASK       0x3
599 #define DITHER_ROTATE(x)  ((((x) & 0xFF) << 24) | (((x) >> 8) & 0x00FFFFFF))
600 static const JLONG dither_matrix[4] = {
601   0x0008020A,
602   0x0C040E06,
603   0x030B0109,
604   0x0F070D05
605 };
606 
607 
is_big_endian(void)608 static INLINE boolean is_big_endian(void)
609 {
610   int test_value = 1;
611   if (*(char *)&test_value != 1)
612     return TRUE;
613   return FALSE;
614 }
615 
616 
617 /* Include inline routines for RGB565 conversion */
618 
619 #define PACK_SHORT_565  PACK_SHORT_565_LE
620 #define PACK_TWO_PIXELS  PACK_TWO_PIXELS_LE
621 #define ycc_rgb565_convert_internal  ycc_rgb565_convert_le
622 #define ycc_rgb565D_convert_internal  ycc_rgb565D_convert_le
623 #define rgb_rgb565_convert_internal  rgb_rgb565_convert_le
624 #define rgb_rgb565D_convert_internal  rgb_rgb565D_convert_le
625 #define gray_rgb565_convert_internal  gray_rgb565_convert_le
626 #define gray_rgb565D_convert_internal  gray_rgb565D_convert_le
627 #include "jdcol565.c"
628 #undef PACK_SHORT_565
629 #undef PACK_TWO_PIXELS
630 #undef ycc_rgb565_convert_internal
631 #undef ycc_rgb565D_convert_internal
632 #undef rgb_rgb565_convert_internal
633 #undef rgb_rgb565D_convert_internal
634 #undef gray_rgb565_convert_internal
635 #undef gray_rgb565D_convert_internal
636 
637 #define PACK_SHORT_565  PACK_SHORT_565_BE
638 #define PACK_TWO_PIXELS  PACK_TWO_PIXELS_BE
639 #define ycc_rgb565_convert_internal  ycc_rgb565_convert_be
640 #define ycc_rgb565D_convert_internal  ycc_rgb565D_convert_be
641 #define rgb_rgb565_convert_internal  rgb_rgb565_convert_be
642 #define rgb_rgb565D_convert_internal  rgb_rgb565D_convert_be
643 #define gray_rgb565_convert_internal  gray_rgb565_convert_be
644 #define gray_rgb565D_convert_internal  gray_rgb565D_convert_be
645 #include "jdcol565.c"
646 #undef PACK_SHORT_565
647 #undef PACK_TWO_PIXELS
648 #undef ycc_rgb565_convert_internal
649 #undef ycc_rgb565D_convert_internal
650 #undef rgb_rgb565_convert_internal
651 #undef rgb_rgb565D_convert_internal
652 #undef gray_rgb565_convert_internal
653 #undef gray_rgb565D_convert_internal
654 
655 
656 METHODDEF(void)
ycc_rgb565_convert(j_decompress_ptr cinfo,JSAMPIMAGE input_buf,JDIMENSION input_row,JSAMPARRAY output_buf,int num_rows)657 ycc_rgb565_convert(j_decompress_ptr cinfo, JSAMPIMAGE input_buf,
658                    JDIMENSION input_row, JSAMPARRAY output_buf, int num_rows)
659 {
660   if (is_big_endian())
661     ycc_rgb565_convert_be(cinfo, input_buf, input_row, output_buf, num_rows);
662   else
663     ycc_rgb565_convert_le(cinfo, input_buf, input_row, output_buf, num_rows);
664 }
665 
666 
667 METHODDEF(void)
ycc_rgb565D_convert(j_decompress_ptr cinfo,JSAMPIMAGE input_buf,JDIMENSION input_row,JSAMPARRAY output_buf,int num_rows)668 ycc_rgb565D_convert(j_decompress_ptr cinfo, JSAMPIMAGE input_buf,
669                     JDIMENSION input_row, JSAMPARRAY output_buf, int num_rows)
670 {
671   if (is_big_endian())
672     ycc_rgb565D_convert_be(cinfo, input_buf, input_row, output_buf, num_rows);
673   else
674     ycc_rgb565D_convert_le(cinfo, input_buf, input_row, output_buf, num_rows);
675 }
676 
677 
678 METHODDEF(void)
rgb_rgb565_convert(j_decompress_ptr cinfo,JSAMPIMAGE input_buf,JDIMENSION input_row,JSAMPARRAY output_buf,int num_rows)679 rgb_rgb565_convert(j_decompress_ptr cinfo, JSAMPIMAGE input_buf,
680                    JDIMENSION input_row, JSAMPARRAY output_buf, int num_rows)
681 {
682   if (is_big_endian())
683     rgb_rgb565_convert_be(cinfo, input_buf, input_row, output_buf, num_rows);
684   else
685     rgb_rgb565_convert_le(cinfo, input_buf, input_row, output_buf, num_rows);
686 }
687 
688 
689 METHODDEF(void)
rgb_rgb565D_convert(j_decompress_ptr cinfo,JSAMPIMAGE input_buf,JDIMENSION input_row,JSAMPARRAY output_buf,int num_rows)690 rgb_rgb565D_convert(j_decompress_ptr cinfo, JSAMPIMAGE input_buf,
691                     JDIMENSION input_row, JSAMPARRAY output_buf, int num_rows)
692 {
693   if (is_big_endian())
694     rgb_rgb565D_convert_be(cinfo, input_buf, input_row, output_buf, num_rows);
695   else
696     rgb_rgb565D_convert_le(cinfo, input_buf, input_row, output_buf, num_rows);
697 }
698 
699 
700 METHODDEF(void)
gray_rgb565_convert(j_decompress_ptr cinfo,JSAMPIMAGE input_buf,JDIMENSION input_row,JSAMPARRAY output_buf,int num_rows)701 gray_rgb565_convert(j_decompress_ptr cinfo, JSAMPIMAGE input_buf,
702                     JDIMENSION input_row, JSAMPARRAY output_buf, int num_rows)
703 {
704   if (is_big_endian())
705     gray_rgb565_convert_be(cinfo, input_buf, input_row, output_buf, num_rows);
706   else
707     gray_rgb565_convert_le(cinfo, input_buf, input_row, output_buf, num_rows);
708 }
709 
710 
711 METHODDEF(void)
gray_rgb565D_convert(j_decompress_ptr cinfo,JSAMPIMAGE input_buf,JDIMENSION input_row,JSAMPARRAY output_buf,int num_rows)712 gray_rgb565D_convert(j_decompress_ptr cinfo, JSAMPIMAGE input_buf,
713                      JDIMENSION input_row, JSAMPARRAY output_buf, int num_rows)
714 {
715   if (is_big_endian())
716     gray_rgb565D_convert_be(cinfo, input_buf, input_row, output_buf, num_rows);
717   else
718     gray_rgb565D_convert_le(cinfo, input_buf, input_row, output_buf, num_rows);
719 }
720 
721 
722 /*
723  * Empty method for start_pass.
724  */
725 
726 METHODDEF(void)
start_pass_dcolor(j_decompress_ptr cinfo)727 start_pass_dcolor(j_decompress_ptr cinfo)
728 {
729   /* no work needed */
730 }
731 
732 
733 /*
734  * Module initialization routine for output colorspace conversion.
735  */
736 
737 GLOBAL(void)
jinit_color_deconverter(j_decompress_ptr cinfo)738 jinit_color_deconverter(j_decompress_ptr cinfo)
739 {
740   my_cconvert_ptr cconvert;
741   int ci;
742 
743   cconvert = (my_cconvert_ptr)
744     (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
745                                 sizeof(my_color_deconverter));
746   cinfo->cconvert = (struct jpeg_color_deconverter *)cconvert;
747   cconvert->pub.start_pass = start_pass_dcolor;
748 
749   /* Make sure num_components agrees with jpeg_color_space */
750   switch (cinfo->jpeg_color_space) {
751   case JCS_GRAYSCALE:
752     if (cinfo->num_components != 1)
753       ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
754     break;
755 
756   case JCS_RGB:
757   case JCS_YCbCr:
758     if (cinfo->num_components != 3)
759       ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
760     break;
761 
762   case JCS_CMYK:
763   case JCS_YCCK:
764     if (cinfo->num_components != 4)
765       ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
766     break;
767 
768   default:                      /* JCS_UNKNOWN can be anything */
769     if (cinfo->num_components < 1)
770       ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
771     break;
772   }
773 
774   /* Set out_color_components and conversion method based on requested space.
775    * Also clear the component_needed flags for any unused components,
776    * so that earlier pipeline stages can avoid useless computation.
777    */
778 
779   switch (cinfo->out_color_space) {
780   case JCS_GRAYSCALE:
781     cinfo->out_color_components = 1;
782     if (cinfo->jpeg_color_space == JCS_GRAYSCALE ||
783         cinfo->jpeg_color_space == JCS_YCbCr) {
784       cconvert->pub.color_convert = grayscale_convert;
785       /* For color->grayscale conversion, only the Y (0) component is needed */
786       for (ci = 1; ci < cinfo->num_components; ci++)
787         cinfo->comp_info[ci].component_needed = FALSE;
788     } else if (cinfo->jpeg_color_space == JCS_RGB) {
789       cconvert->pub.color_convert = rgb_gray_convert;
790       build_rgb_y_table(cinfo);
791     } else
792       ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
793     break;
794 
795   case JCS_RGB:
796   case JCS_EXT_RGB:
797   case JCS_EXT_RGBX:
798   case JCS_EXT_BGR:
799   case JCS_EXT_BGRX:
800   case JCS_EXT_XBGR:
801   case JCS_EXT_XRGB:
802   case JCS_EXT_RGBA:
803   case JCS_EXT_BGRA:
804   case JCS_EXT_ABGR:
805   case JCS_EXT_ARGB:
806     cinfo->out_color_components = rgb_pixelsize[cinfo->out_color_space];
807     if (cinfo->jpeg_color_space == JCS_YCbCr) {
808       if (jsimd_can_ycc_rgb())
809         cconvert->pub.color_convert = jsimd_ycc_rgb_convert;
810       else {
811         cconvert->pub.color_convert = ycc_rgb_convert;
812         build_ycc_rgb_table(cinfo);
813       }
814     } else if (cinfo->jpeg_color_space == JCS_GRAYSCALE) {
815       cconvert->pub.color_convert = gray_rgb_convert;
816     } else if (cinfo->jpeg_color_space == JCS_RGB) {
817       if (rgb_red[cinfo->out_color_space] == 0 &&
818           rgb_green[cinfo->out_color_space] == 1 &&
819           rgb_blue[cinfo->out_color_space] == 2 &&
820           rgb_pixelsize[cinfo->out_color_space] == 3)
821         cconvert->pub.color_convert = null_convert;
822       else
823         cconvert->pub.color_convert = rgb_rgb_convert;
824     } else
825       ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
826     break;
827 
828   case JCS_RGB565:
829     cinfo->out_color_components = 3;
830     if (cinfo->dither_mode == JDITHER_NONE) {
831       if (cinfo->jpeg_color_space == JCS_YCbCr) {
832         if (jsimd_can_ycc_rgb565())
833           cconvert->pub.color_convert = jsimd_ycc_rgb565_convert;
834         else {
835           cconvert->pub.color_convert = ycc_rgb565_convert;
836           build_ycc_rgb_table(cinfo);
837         }
838       } else if (cinfo->jpeg_color_space == JCS_GRAYSCALE) {
839         cconvert->pub.color_convert = gray_rgb565_convert;
840       } else if (cinfo->jpeg_color_space == JCS_RGB) {
841         cconvert->pub.color_convert = rgb_rgb565_convert;
842       } else
843         ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
844     } else {
845       /* only ordered dithering is supported */
846       if (cinfo->jpeg_color_space == JCS_YCbCr) {
847         cconvert->pub.color_convert = ycc_rgb565D_convert;
848         build_ycc_rgb_table(cinfo);
849       } else if (cinfo->jpeg_color_space == JCS_GRAYSCALE) {
850         cconvert->pub.color_convert = gray_rgb565D_convert;
851       } else if (cinfo->jpeg_color_space == JCS_RGB) {
852         cconvert->pub.color_convert = rgb_rgb565D_convert;
853       } else
854         ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
855     }
856     break;
857 
858   case JCS_CMYK:
859     cinfo->out_color_components = 4;
860     if (cinfo->jpeg_color_space == JCS_YCCK) {
861       cconvert->pub.color_convert = ycck_cmyk_convert;
862       build_ycc_rgb_table(cinfo);
863     } else if (cinfo->jpeg_color_space == JCS_CMYK) {
864       cconvert->pub.color_convert = null_convert;
865     } else
866       ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
867     break;
868 
869   default:
870     /* Permit null conversion to same output space */
871     if (cinfo->out_color_space == cinfo->jpeg_color_space) {
872       cinfo->out_color_components = cinfo->num_components;
873       cconvert->pub.color_convert = null_convert;
874     } else                      /* unsupported non-null conversion */
875       ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
876     break;
877   }
878 
879   if (cinfo->quantize_colors)
880     cinfo->output_components = 1; /* single colormapped output component */
881   else
882     cinfo->output_components = cinfo->out_color_components;
883 }
884