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ADD: MuPDF v1.26.7: the MuPDF source as downloaded by a default build of PyMuPDF 1.26.4. The directory name has changed: no version number in the expanded directory now.
author Franz Glasner <fzglas.hg@dom66.de>
date Mon, 15 Sep 2025 11:43:07 +0200
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1:1d09e1dec1d9 2:b50eed0cc0ef
1 /*
2 * jcparam.c
3 *
4 * Copyright (C) 1991-1998, Thomas G. Lane.
5 * Modified 2003-2022 by Guido Vollbeding.
6 * This file is part of the Independent JPEG Group's software.
7 * For conditions of distribution and use, see the accompanying README file.
8 *
9 * This file contains optional default-setting code for the JPEG compressor.
10 * Applications do not have to use this file, but those that don't use it
11 * must know a lot more about the innards of the JPEG code.
12 */
13
14 #define JPEG_INTERNALS
15 #include "jinclude.h"
16 #include "jpeglib.h"
17
18
19 /*
20 * Quantization table setup routines
21 */
22
23 GLOBAL(void)
24 jpeg_add_quant_table (j_compress_ptr cinfo, int which_tbl,
25 const unsigned int *basic_table,
26 int scale_factor, boolean force_baseline)
27 /* Define a quantization table equal to the basic_table times
28 * a scale factor (given as a percentage).
29 * If force_baseline is TRUE, the computed quantization table entries
30 * are limited to 1..255 for JPEG baseline compatibility.
31 */
32 {
33 JQUANT_TBL ** qtblptr;
34 int i;
35 long temp;
36
37 /* Safety check to ensure start_compress not called yet. */
38 if (cinfo->global_state != CSTATE_START)
39 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
40
41 if (which_tbl < 0 || which_tbl >= NUM_QUANT_TBLS)
42 ERREXIT1(cinfo, JERR_DQT_INDEX, which_tbl);
43
44 qtblptr = & cinfo->quant_tbl_ptrs[which_tbl];
45
46 if (*qtblptr == NULL)
47 *qtblptr = jpeg_alloc_quant_table((j_common_ptr) cinfo);
48
49 for (i = 0; i < DCTSIZE2; i++) {
50 temp = ((long) basic_table[i] * scale_factor + 50L) / 100L;
51 /* limit the values to the valid range */
52 if (temp <= 0L) temp = 1L;
53 if (temp > 32767L) temp = 32767L; /* max quantizer needed for 12 bits */
54 if (force_baseline && temp > 255L)
55 temp = 255L; /* limit to baseline range if requested */
56 (*qtblptr)->quantval[i] = (UINT16) temp;
57 }
58
59 /* Initialize sent_table FALSE so table will be written to JPEG file. */
60 (*qtblptr)->sent_table = FALSE;
61 }
62
63
64 /* These are the sample quantization tables given in JPEG spec section K.1.
65 * NOTE: chrominance DC value is changed from 17 to 16 for lossless support.
66 * The spec says that the values given produce "good" quality,
67 * and when divided by 2, "very good" quality.
68 */
69 static const unsigned int std_luminance_quant_tbl[DCTSIZE2] = {
70 16, 11, 10, 16, 24, 40, 51, 61,
71 12, 12, 14, 19, 26, 58, 60, 55,
72 14, 13, 16, 24, 40, 57, 69, 56,
73 14, 17, 22, 29, 51, 87, 80, 62,
74 18, 22, 37, 56, 68, 109, 103, 77,
75 24, 35, 55, 64, 81, 104, 113, 92,
76 49, 64, 78, 87, 103, 121, 120, 101,
77 72, 92, 95, 98, 112, 100, 103, 99
78 };
79 static const unsigned int std_chrominance_quant_tbl[DCTSIZE2] = {
80 16, 18, 24, 47, 99, 99, 99, 99,
81 18, 21, 26, 66, 99, 99, 99, 99,
82 24, 26, 56, 99, 99, 99, 99, 99,
83 47, 66, 99, 99, 99, 99, 99, 99,
84 99, 99, 99, 99, 99, 99, 99, 99,
85 99, 99, 99, 99, 99, 99, 99, 99,
86 99, 99, 99, 99, 99, 99, 99, 99,
87 99, 99, 99, 99, 99, 99, 99, 99
88 };
89
90
91 GLOBAL(void)
92 jpeg_default_qtables (j_compress_ptr cinfo, boolean force_baseline)
93 /* Set or change the 'quality' (quantization) setting, using default tables
94 * and straight percentage-scaling quality scales.
95 * This entry point allows different scalings for luminance and chrominance.
96 */
97 {
98 /* Set up two quantization tables using the specified scaling */
99 jpeg_add_quant_table(cinfo, 0, std_luminance_quant_tbl,
100 cinfo->q_scale_factor[0], force_baseline);
101 jpeg_add_quant_table(cinfo, 1, std_chrominance_quant_tbl,
102 cinfo->q_scale_factor[1], force_baseline);
103 }
104
105
106 GLOBAL(void)
107 jpeg_set_linear_quality (j_compress_ptr cinfo, int scale_factor,
108 boolean force_baseline)
109 /* Set or change the 'quality' (quantization) setting, using default tables
110 * and a straight percentage-scaling quality scale. In most cases it's better
111 * to use jpeg_set_quality (below); this entry point is provided for
112 * applications that insist on a linear percentage scaling.
113 */
114 {
115 /* Set up two quantization tables using the specified scaling */
116 jpeg_add_quant_table(cinfo, 0, std_luminance_quant_tbl,
117 scale_factor, force_baseline);
118 jpeg_add_quant_table(cinfo, 1, std_chrominance_quant_tbl,
119 scale_factor, force_baseline);
120 }
121
122
123 GLOBAL(int)
124 jpeg_quality_scaling (int quality)
125 /* Convert a user-specified quality rating to a percentage scaling factor
126 * for an underlying quantization table, using our recommended scaling curve.
127 * The input 'quality' factor should be 0 (terrible) to 100 (very good).
128 */
129 {
130 /* Safety limit on quality factor. Convert 0 to 1 to avoid zero divide. */
131 if (quality <= 0) quality = 1;
132 if (quality > 100) quality = 100;
133
134 /* The basic table is used as-is (scaling 100) for a quality of 50.
135 * Qualities 50..100 are converted to scaling percentage 200 - 2*Q;
136 * note that at Q=100 the scaling is 0, which will cause jpeg_add_quant_table
137 * to make all the table entries 1 (hence, minimum quantization loss).
138 * Qualities 1..50 are converted to scaling percentage 5000/Q.
139 */
140 if (quality < 50)
141 quality = 5000 / quality;
142 else
143 quality = 200 - quality*2;
144
145 return quality;
146 }
147
148
149 GLOBAL(void)
150 jpeg_set_quality (j_compress_ptr cinfo, int quality, boolean force_baseline)
151 /* Set or change the 'quality' (quantization) setting, using default tables.
152 * This is the standard quality-adjusting entry point for typical user
153 * interfaces; only those who want detailed control over quantization tables
154 * would use the preceding routines directly.
155 */
156 {
157 /* Convert user 0-100 rating to percentage scaling */
158 quality = jpeg_quality_scaling(quality);
159
160 /* Set up standard quality tables */
161 jpeg_set_linear_quality(cinfo, quality, force_baseline);
162 }
163
164
165 /*
166 * Reset standard Huffman tables
167 */
168
169 LOCAL(void)
170 std_huff_tables (j_compress_ptr cinfo)
171 {
172 if (cinfo->dc_huff_tbl_ptrs[0] != NULL)
173 (void) jpeg_std_huff_table((j_common_ptr) cinfo, TRUE, 0);
174
175 if (cinfo->ac_huff_tbl_ptrs[0] != NULL)
176 (void) jpeg_std_huff_table((j_common_ptr) cinfo, FALSE, 0);
177
178 if (cinfo->dc_huff_tbl_ptrs[1] != NULL)
179 (void) jpeg_std_huff_table((j_common_ptr) cinfo, TRUE, 1);
180
181 if (cinfo->ac_huff_tbl_ptrs[1] != NULL)
182 (void) jpeg_std_huff_table((j_common_ptr) cinfo, FALSE, 1);
183 }
184
185
186 /*
187 * Default parameter setup for compression.
188 *
189 * Applications that don't choose to use this routine must do their
190 * own setup of all these parameters. Alternately, you can call this
191 * to establish defaults and then alter parameters selectively. This
192 * is the recommended approach since, if we add any new parameters,
193 * your code will still work (they'll be set to reasonable defaults).
194 */
195
196 GLOBAL(void)
197 jpeg_set_defaults (j_compress_ptr cinfo)
198 {
199 int i;
200
201 /* Safety check to ensure start_compress not called yet. */
202 if (cinfo->global_state != CSTATE_START)
203 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
204
205 /* Allocate comp_info array large enough for maximum component count.
206 * Array is made permanent in case application wants to compress
207 * multiple images at same param settings.
208 */
209 if (cinfo->comp_info == NULL)
210 cinfo->comp_info = (jpeg_component_info *)
211 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
212 MAX_COMPONENTS * SIZEOF(jpeg_component_info));
213
214 /* Initialize everything not dependent on the color space */
215
216 cinfo->scale_num = 1; /* 1:1 scaling */
217 cinfo->scale_denom = 1;
218 cinfo->data_precision = BITS_IN_JSAMPLE;
219 /* Set up two quantization tables using default quality of 75 */
220 jpeg_set_quality(cinfo, 75, TRUE);
221 /* Reset standard Huffman tables */
222 std_huff_tables(cinfo);
223
224 /* Initialize default arithmetic coding conditioning */
225 for (i = 0; i < NUM_ARITH_TBLS; i++) {
226 cinfo->arith_dc_L[i] = 0;
227 cinfo->arith_dc_U[i] = 1;
228 cinfo->arith_ac_K[i] = 5;
229 }
230
231 /* Default is no multiple-scan output */
232 cinfo->scan_info = NULL;
233 cinfo->num_scans = 0;
234
235 /* Expect normal source image, not raw downsampled data */
236 cinfo->raw_data_in = FALSE;
237
238 /* The standard Huffman tables are only valid for 8-bit data precision.
239 * If the precision is higher, use arithmetic coding.
240 * (Alternatively, using Huffman coding would be possible with forcing
241 * optimization on so that usable tables will be computed, or by
242 * supplying default tables that are valid for the desired precision.)
243 * Otherwise, use Huffman coding by default.
244 */
245 cinfo->arith_code = cinfo->data_precision > 8 ? TRUE : FALSE;
246
247 /* By default, don't do extra passes to optimize entropy coding */
248 cinfo->optimize_coding = FALSE;
249
250 /* By default, use the simpler non-cosited sampling alignment */
251 cinfo->CCIR601_sampling = FALSE;
252
253 /* By default, apply fancy downsampling */
254 cinfo->do_fancy_downsampling = TRUE;
255
256 /* No input smoothing */
257 cinfo->smoothing_factor = 0;
258
259 /* DCT algorithm preference */
260 cinfo->dct_method = JDCT_DEFAULT;
261
262 /* No restart markers */
263 cinfo->restart_interval = 0;
264 cinfo->restart_in_rows = 0;
265
266 /* Fill in default JFIF marker parameters. Note that whether the marker
267 * will actually be written is determined by jpeg_set_colorspace.
268 *
269 * By default, the library emits JFIF version code 1.01.
270 * An application that wants to emit JFIF 1.02 extension markers should set
271 * JFIF_minor_version to 2. We could probably get away with just defaulting
272 * to 1.02, but there may still be some decoders in use that will complain
273 * about that; saying 1.01 should minimize compatibility problems.
274 *
275 * For wide gamut colorspaces (BG_RGB and BG_YCC), the major version will be
276 * overridden by jpeg_set_colorspace and set to 2.
277 */
278 cinfo->JFIF_major_version = 1; /* Default JFIF version = 1.01 */
279 cinfo->JFIF_minor_version = 1;
280 cinfo->density_unit = 0; /* Pixel size is unknown by default */
281 cinfo->X_density = 1; /* Pixel aspect ratio is square by default */
282 cinfo->Y_density = 1;
283
284 /* No color transform */
285 cinfo->color_transform = JCT_NONE;
286
287 /* Choose JPEG colorspace based on input space, set defaults accordingly */
288
289 jpeg_default_colorspace(cinfo);
290 }
291
292
293 /*
294 * Select an appropriate JPEG colorspace for in_color_space.
295 */
296
297 GLOBAL(void)
298 jpeg_default_colorspace (j_compress_ptr cinfo)
299 {
300 switch (cinfo->in_color_space) {
301 case JCS_UNKNOWN:
302 jpeg_set_colorspace(cinfo, JCS_UNKNOWN);
303 break;
304 case JCS_GRAYSCALE:
305 jpeg_set_colorspace(cinfo, JCS_GRAYSCALE);
306 break;
307 case JCS_RGB:
308 jpeg_set_colorspace(cinfo, JCS_YCbCr);
309 break;
310 case JCS_YCbCr:
311 jpeg_set_colorspace(cinfo, JCS_YCbCr);
312 break;
313 case JCS_CMYK:
314 jpeg_set_colorspace(cinfo, JCS_CMYK); /* By default, no translation */
315 break;
316 case JCS_YCCK:
317 jpeg_set_colorspace(cinfo, JCS_YCCK);
318 break;
319 case JCS_BG_RGB:
320 /* No translation for now -- conversion to BG_YCC not yet supportet */
321 jpeg_set_colorspace(cinfo, JCS_BG_RGB);
322 break;
323 case JCS_BG_YCC:
324 jpeg_set_colorspace(cinfo, JCS_BG_YCC);
325 break;
326 default:
327 ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
328 }
329 }
330
331
332 /*
333 * Set the JPEG colorspace, and choose colorspace-dependent default values.
334 */
335
336 GLOBAL(void)
337 jpeg_set_colorspace (j_compress_ptr cinfo, J_COLOR_SPACE colorspace)
338 {
339 jpeg_component_info * compptr;
340 int ci;
341
342 #define SET_COMP(index,id,hsamp,vsamp,quant,dctbl,actbl) \
343 (compptr = &cinfo->comp_info[index], \
344 compptr->component_id = (id), \
345 compptr->h_samp_factor = (hsamp), \
346 compptr->v_samp_factor = (vsamp), \
347 compptr->quant_tbl_no = (quant), \
348 compptr->dc_tbl_no = (dctbl), \
349 compptr->ac_tbl_no = (actbl) )
350
351 /* Safety check to ensure start_compress not called yet. */
352 if (cinfo->global_state != CSTATE_START)
353 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
354
355 /* For all colorspaces, we use Q and Huff tables 0 for luminance components,
356 * tables 1 for chrominance components.
357 */
358
359 cinfo->jpeg_color_space = colorspace;
360
361 cinfo->write_JFIF_header = FALSE; /* No marker for non-JFIF colorspaces */
362 cinfo->write_Adobe_marker = FALSE; /* write no Adobe marker by default */
363
364 switch (colorspace) {
365 case JCS_UNKNOWN:
366 cinfo->num_components = cinfo->input_components;
367 if (cinfo->num_components < 1 || cinfo->num_components > MAX_COMPONENTS)
368 ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components,
369 MAX_COMPONENTS);
370 for (ci = 0; ci < cinfo->num_components; ci++) {
371 SET_COMP(ci, ci, 1,1, 0, 0,0);
372 }
373 break;
374 case JCS_GRAYSCALE:
375 cinfo->write_JFIF_header = TRUE; /* Write a JFIF marker */
376 cinfo->num_components = 1;
377 /* JFIF specifies component ID 1 */
378 SET_COMP(0, 0x01, 1,1, 0, 0,0);
379 break;
380 case JCS_RGB:
381 cinfo->write_Adobe_marker = TRUE; /* write Adobe marker to flag RGB */
382 cinfo->num_components = 3;
383 SET_COMP(0, 0x52 /* 'R' */, 1,1,
384 cinfo->color_transform == JCT_SUBTRACT_GREEN ? 1 : 0,
385 cinfo->color_transform == JCT_SUBTRACT_GREEN ? 1 : 0,
386 cinfo->color_transform == JCT_SUBTRACT_GREEN ? 1 : 0);
387 SET_COMP(1, 0x47 /* 'G' */, 1,1, 0, 0,0);
388 SET_COMP(2, 0x42 /* 'B' */, 1,1,
389 cinfo->color_transform == JCT_SUBTRACT_GREEN ? 1 : 0,
390 cinfo->color_transform == JCT_SUBTRACT_GREEN ? 1 : 0,
391 cinfo->color_transform == JCT_SUBTRACT_GREEN ? 1 : 0);
392 break;
393 case JCS_YCbCr:
394 cinfo->write_JFIF_header = TRUE; /* Write a JFIF marker */
395 cinfo->num_components = 3;
396 /* JFIF specifies component IDs 1,2,3 */
397 /* We default to 2x2 subsamples of chrominance */
398 SET_COMP(0, 0x01, 2,2, 0, 0,0);
399 SET_COMP(1, 0x02, 1,1, 1, 1,1);
400 SET_COMP(2, 0x03, 1,1, 1, 1,1);
401 break;
402 case JCS_CMYK:
403 cinfo->write_Adobe_marker = TRUE; /* write Adobe marker to flag CMYK */
404 cinfo->num_components = 4;
405 SET_COMP(0, 0x43 /* 'C' */, 1,1, 0, 0,0);
406 SET_COMP(1, 0x4D /* 'M' */, 1,1, 0, 0,0);
407 SET_COMP(2, 0x59 /* 'Y' */, 1,1, 0, 0,0);
408 SET_COMP(3, 0x4B /* 'K' */, 1,1, 0, 0,0);
409 break;
410 case JCS_YCCK:
411 cinfo->write_Adobe_marker = TRUE; /* write Adobe marker to flag YCCK */
412 cinfo->num_components = 4;
413 SET_COMP(0, 0x01, 2,2, 0, 0,0);
414 SET_COMP(1, 0x02, 1,1, 1, 1,1);
415 SET_COMP(2, 0x03, 1,1, 1, 1,1);
416 SET_COMP(3, 0x04, 2,2, 0, 0,0);
417 break;
418 case JCS_BG_RGB:
419 cinfo->write_JFIF_header = TRUE; /* Write a JFIF marker */
420 cinfo->JFIF_major_version = 2; /* Set JFIF major version = 2 */
421 cinfo->num_components = 3;
422 /* Add offset 0x20 to the normal R/G/B component IDs */
423 SET_COMP(0, 0x72 /* 'r' */, 1,1,
424 cinfo->color_transform == JCT_SUBTRACT_GREEN ? 1 : 0,
425 cinfo->color_transform == JCT_SUBTRACT_GREEN ? 1 : 0,
426 cinfo->color_transform == JCT_SUBTRACT_GREEN ? 1 : 0);
427 SET_COMP(1, 0x67 /* 'g' */, 1,1, 0, 0,0);
428 SET_COMP(2, 0x62 /* 'b' */, 1,1,
429 cinfo->color_transform == JCT_SUBTRACT_GREEN ? 1 : 0,
430 cinfo->color_transform == JCT_SUBTRACT_GREEN ? 1 : 0,
431 cinfo->color_transform == JCT_SUBTRACT_GREEN ? 1 : 0);
432 break;
433 case JCS_BG_YCC:
434 cinfo->write_JFIF_header = TRUE; /* Write a JFIF marker */
435 cinfo->JFIF_major_version = 2; /* Set JFIF major version = 2 */
436 cinfo->num_components = 3;
437 /* Add offset 0x20 to the normal Cb/Cr component IDs */
438 /* We default to 2x2 subsamples of chrominance */
439 SET_COMP(0, 0x01, 2,2, 0, 0,0);
440 SET_COMP(1, 0x22, 1,1, 1, 1,1);
441 SET_COMP(2, 0x23, 1,1, 1, 1,1);
442 break;
443 default:
444 ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
445 }
446 }
447
448
449 #ifdef C_PROGRESSIVE_SUPPORTED
450
451 LOCAL(jpeg_scan_info *)
452 fill_a_scan (jpeg_scan_info * scanptr, int ci,
453 int Ss, int Se, int Ah, int Al)
454 /* Support routine: generate one scan for specified component */
455 {
456 scanptr->comps_in_scan = 1;
457 scanptr->component_index[0] = ci;
458 scanptr->Ss = Ss;
459 scanptr->Se = Se;
460 scanptr->Ah = Ah;
461 scanptr->Al = Al;
462 scanptr++;
463 return scanptr;
464 }
465
466 LOCAL(jpeg_scan_info *)
467 fill_scans (jpeg_scan_info * scanptr, int ncomps,
468 int Ss, int Se, int Ah, int Al)
469 /* Support routine: generate one scan for each component */
470 {
471 int ci;
472
473 for (ci = 0; ci < ncomps; ci++) {
474 scanptr->comps_in_scan = 1;
475 scanptr->component_index[0] = ci;
476 scanptr->Ss = Ss;
477 scanptr->Se = Se;
478 scanptr->Ah = Ah;
479 scanptr->Al = Al;
480 scanptr++;
481 }
482 return scanptr;
483 }
484
485 LOCAL(jpeg_scan_info *)
486 fill_dc_scans (jpeg_scan_info * scanptr, int ncomps, int Ah, int Al)
487 /* Support routine: generate interleaved DC scan if possible, else N scans */
488 {
489 int ci;
490
491 if (ncomps <= MAX_COMPS_IN_SCAN) {
492 /* Single interleaved DC scan */
493 scanptr->comps_in_scan = ncomps;
494 for (ci = 0; ci < ncomps; ci++)
495 scanptr->component_index[ci] = ci;
496 scanptr->Ss = scanptr->Se = 0;
497 scanptr->Ah = Ah;
498 scanptr->Al = Al;
499 scanptr++;
500 } else {
501 /* Noninterleaved DC scan for each component */
502 scanptr = fill_scans(scanptr, ncomps, 0, 0, Ah, Al);
503 }
504 return scanptr;
505 }
506
507
508 /*
509 * Create a recommended progressive-JPEG script.
510 * cinfo->num_components and cinfo->jpeg_color_space must be correct.
511 */
512
513 GLOBAL(void)
514 jpeg_simple_progression (j_compress_ptr cinfo)
515 {
516 int ncomps = cinfo->num_components;
517 int nscans;
518 jpeg_scan_info * scanptr;
519
520 /* Safety check to ensure start_compress not called yet. */
521 if (cinfo->global_state != CSTATE_START)
522 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
523
524 /* Figure space needed for script. Calculation must match code below! */
525 if (ncomps == 3 &&
526 (cinfo->jpeg_color_space == JCS_YCbCr ||
527 cinfo->jpeg_color_space == JCS_BG_YCC)) {
528 /* Custom script for YCC color images. */
529 nscans = 10;
530 } else {
531 /* All-purpose script for other color spaces. */
532 if (ncomps > MAX_COMPS_IN_SCAN)
533 nscans = 6 * ncomps; /* 2 DC + 4 AC scans per component */
534 else
535 nscans = 2 + 4 * ncomps; /* 2 DC scans; 4 AC scans per component */
536 }
537
538 /* Allocate space for script.
539 * We need to put it in the permanent pool in case the application performs
540 * multiple compressions without changing the settings. To avoid a memory
541 * leak if jpeg_simple_progression is called repeatedly for the same JPEG
542 * object, we try to re-use previously allocated space, and we allocate
543 * enough space to handle YCC even if initially asked for grayscale.
544 */
545 if (cinfo->script_space == NULL || cinfo->script_space_size < nscans) {
546 cinfo->script_space_size = MAX(nscans, 10);
547 cinfo->script_space = (jpeg_scan_info *)
548 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
549 cinfo->script_space_size * SIZEOF(jpeg_scan_info));
550 }
551 scanptr = cinfo->script_space;
552 cinfo->scan_info = scanptr;
553 cinfo->num_scans = nscans;
554
555 if (ncomps == 3 &&
556 (cinfo->jpeg_color_space == JCS_YCbCr ||
557 cinfo->jpeg_color_space == JCS_BG_YCC)) {
558 /* Custom script for YCC color images. */
559 /* Initial DC scan */
560 scanptr = fill_dc_scans(scanptr, ncomps, 0, 1);
561 /* Initial AC scan: get some luma data out in a hurry */
562 scanptr = fill_a_scan(scanptr, 0, 1, 5, 0, 2);
563 /* Chroma data is too small to be worth expending many scans on */
564 scanptr = fill_a_scan(scanptr, 2, 1, 63, 0, 1);
565 scanptr = fill_a_scan(scanptr, 1, 1, 63, 0, 1);
566 /* Complete spectral selection for luma AC */
567 scanptr = fill_a_scan(scanptr, 0, 6, 63, 0, 2);
568 /* Refine next bit of luma AC */
569 scanptr = fill_a_scan(scanptr, 0, 1, 63, 2, 1);
570 /* Finish DC successive approximation */
571 scanptr = fill_dc_scans(scanptr, ncomps, 1, 0);
572 /* Finish AC successive approximation */
573 scanptr = fill_a_scan(scanptr, 2, 1, 63, 1, 0);
574 scanptr = fill_a_scan(scanptr, 1, 1, 63, 1, 0);
575 /* Luma bottom bit comes last since it's usually largest scan */
576 scanptr = fill_a_scan(scanptr, 0, 1, 63, 1, 0);
577 } else {
578 /* All-purpose script for other color spaces. */
579 /* Successive approximation first pass */
580 scanptr = fill_dc_scans(scanptr, ncomps, 0, 1);
581 scanptr = fill_scans(scanptr, ncomps, 1, 5, 0, 2);
582 scanptr = fill_scans(scanptr, ncomps, 6, 63, 0, 2);
583 /* Successive approximation second pass */
584 scanptr = fill_scans(scanptr, ncomps, 1, 63, 2, 1);
585 /* Successive approximation final pass */
586 scanptr = fill_dc_scans(scanptr, ncomps, 1, 0);
587 scanptr = fill_scans(scanptr, ncomps, 1, 63, 1, 0);
588 }
589 }
590
591 #endif /* C_PROGRESSIVE_SUPPORTED */