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comparison mupdf-source/thirdparty/libjpeg/jcmaster.c @ 2:b50eed0cc0ef upstream

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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 * jcmaster.c
3 *
4 * Copyright (C) 1991-1997, Thomas G. Lane.
5 * Modified 2003-2020 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 master control logic for the JPEG compressor.
10 * These routines are concerned with parameter validation, initial setup,
11 * and inter-pass control (determining the number of passes and the work
12 * to be done in each pass).
13 */
14
15 #define JPEG_INTERNALS
16 #include "jinclude.h"
17 #include "jpeglib.h"
18
19
20 /* Private state */
21
22 typedef enum {
23 main_pass, /* input data, also do first output step */
24 huff_opt_pass, /* Huffman code optimization pass */
25 output_pass /* data output pass */
26 } c_pass_type;
27
28 typedef struct {
29 struct jpeg_comp_master pub; /* public fields */
30
31 c_pass_type pass_type; /* the type of the current pass */
32
33 int pass_number; /* # of passes completed */
34 int total_passes; /* total # of passes needed */
35
36 int scan_number; /* current index in scan_info[] */
37 } my_comp_master;
38
39 typedef my_comp_master * my_master_ptr;
40
41
42 /*
43 * Support routines that do various essential calculations.
44 */
45
46 LOCAL(void)
47 initial_setup (j_compress_ptr cinfo)
48 /* Do computations that are needed before master selection phase */
49 {
50 int ci, ssize;
51 jpeg_component_info *compptr;
52
53 /* Sanity check on block_size */
54 if (cinfo->block_size < 1 || cinfo->block_size > 16)
55 ERREXIT2(cinfo, JERR_BAD_DCTSIZE, cinfo->block_size, cinfo->block_size);
56
57 /* Derive natural_order from block_size */
58 switch (cinfo->block_size) {
59 case 2: cinfo->natural_order = jpeg_natural_order2; break;
60 case 3: cinfo->natural_order = jpeg_natural_order3; break;
61 case 4: cinfo->natural_order = jpeg_natural_order4; break;
62 case 5: cinfo->natural_order = jpeg_natural_order5; break;
63 case 6: cinfo->natural_order = jpeg_natural_order6; break;
64 case 7: cinfo->natural_order = jpeg_natural_order7; break;
65 default: cinfo->natural_order = jpeg_natural_order;
66 }
67
68 /* Derive lim_Se from block_size */
69 cinfo->lim_Se = cinfo->block_size < DCTSIZE ?
70 cinfo->block_size * cinfo->block_size - 1 : DCTSIZE2-1;
71
72 /* Sanity check on image dimensions */
73 if (cinfo->jpeg_height <= 0 || cinfo->jpeg_width <= 0 ||
74 cinfo->num_components <= 0)
75 ERREXIT(cinfo, JERR_EMPTY_IMAGE);
76
77 /* Make sure image isn't bigger than I can handle */
78 if ((long) cinfo->jpeg_height > (long) JPEG_MAX_DIMENSION ||
79 (long) cinfo->jpeg_width > (long) JPEG_MAX_DIMENSION)
80 ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) JPEG_MAX_DIMENSION);
81
82 /* Only 8 to 12 bits data precision are supported for DCT based JPEG */
83 if (cinfo->data_precision < 8 || cinfo->data_precision > 12)
84 ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision);
85
86 /* Check that number of components won't exceed internal array sizes */
87 if (cinfo->num_components > MAX_COMPONENTS)
88 ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components,
89 MAX_COMPONENTS);
90
91 /* Compute maximum sampling factors; check factor validity */
92 cinfo->max_h_samp_factor = 1;
93 cinfo->max_v_samp_factor = 1;
94 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
95 ci++, compptr++) {
96 if (compptr->h_samp_factor<=0 || compptr->h_samp_factor>MAX_SAMP_FACTOR ||
97 compptr->v_samp_factor<=0 || compptr->v_samp_factor>MAX_SAMP_FACTOR)
98 ERREXIT(cinfo, JERR_BAD_SAMPLING);
99 cinfo->max_h_samp_factor = MAX(cinfo->max_h_samp_factor,
100 compptr->h_samp_factor);
101 cinfo->max_v_samp_factor = MAX(cinfo->max_v_samp_factor,
102 compptr->v_samp_factor);
103 }
104
105 /* Compute dimensions of components */
106 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
107 ci++, compptr++) {
108 /* Fill in the correct component_index value; don't rely on application */
109 compptr->component_index = ci;
110 /* In selecting the actual DCT scaling for each component, we try to
111 * scale down the chroma components via DCT scaling rather than downsampling.
112 * This saves time if the downsampler gets to use 1:1 scaling.
113 * Note this code adapts subsampling ratios which are powers of 2.
114 */
115 ssize = 1;
116 #ifdef DCT_SCALING_SUPPORTED
117 if (! cinfo->raw_data_in)
118 while (cinfo->min_DCT_h_scaled_size * ssize <=
119 (cinfo->do_fancy_downsampling ? DCTSIZE : DCTSIZE / 2) &&
120 (cinfo->max_h_samp_factor % (compptr->h_samp_factor * ssize * 2)) ==
121 0) {
122 ssize = ssize * 2;
123 }
124 #endif
125 compptr->DCT_h_scaled_size = cinfo->min_DCT_h_scaled_size * ssize;
126 ssize = 1;
127 #ifdef DCT_SCALING_SUPPORTED
128 if (! cinfo->raw_data_in)
129 while (cinfo->min_DCT_v_scaled_size * ssize <=
130 (cinfo->do_fancy_downsampling ? DCTSIZE : DCTSIZE / 2) &&
131 (cinfo->max_v_samp_factor % (compptr->v_samp_factor * ssize * 2)) ==
132 0) {
133 ssize = ssize * 2;
134 }
135 #endif
136 compptr->DCT_v_scaled_size = cinfo->min_DCT_v_scaled_size * ssize;
137
138 /* We don't support DCT ratios larger than 2. */
139 if (compptr->DCT_h_scaled_size > compptr->DCT_v_scaled_size * 2)
140 compptr->DCT_h_scaled_size = compptr->DCT_v_scaled_size * 2;
141 else if (compptr->DCT_v_scaled_size > compptr->DCT_h_scaled_size * 2)
142 compptr->DCT_v_scaled_size = compptr->DCT_h_scaled_size * 2;
143
144 /* Size in DCT blocks */
145 compptr->width_in_blocks = (JDIMENSION)
146 jdiv_round_up((long) cinfo->jpeg_width * (long) compptr->h_samp_factor,
147 (long) (cinfo->max_h_samp_factor * cinfo->block_size));
148 compptr->height_in_blocks = (JDIMENSION)
149 jdiv_round_up((long) cinfo->jpeg_height * (long) compptr->v_samp_factor,
150 (long) (cinfo->max_v_samp_factor * cinfo->block_size));
151 /* Size in samples */
152 compptr->downsampled_width = (JDIMENSION)
153 jdiv_round_up((long) cinfo->jpeg_width *
154 (long) (compptr->h_samp_factor * compptr->DCT_h_scaled_size),
155 (long) (cinfo->max_h_samp_factor * cinfo->block_size));
156 compptr->downsampled_height = (JDIMENSION)
157 jdiv_round_up((long) cinfo->jpeg_height *
158 (long) (compptr->v_samp_factor * compptr->DCT_v_scaled_size),
159 (long) (cinfo->max_v_samp_factor * cinfo->block_size));
160 /* Don't need quantization scale after DCT,
161 * until color conversion says otherwise.
162 */
163 compptr->component_needed = FALSE;
164 }
165
166 /* Compute number of fully interleaved MCU rows (number of times that
167 * main controller will call coefficient controller).
168 */
169 cinfo->total_iMCU_rows = (JDIMENSION)
170 jdiv_round_up((long) cinfo->jpeg_height,
171 (long) (cinfo->max_v_samp_factor * cinfo->block_size));
172 }
173
174
175 #ifdef C_MULTISCAN_FILES_SUPPORTED
176
177 LOCAL(void)
178 validate_script (j_compress_ptr cinfo)
179 /* Verify that the scan script in cinfo->scan_info[] is valid; also
180 * determine whether it uses progressive JPEG, and set cinfo->progressive_mode.
181 */
182 {
183 const jpeg_scan_info * scanptr;
184 int scanno, ncomps, ci, coefi, thisi;
185 int Ss, Se, Ah, Al;
186 boolean component_sent[MAX_COMPONENTS];
187 #ifdef C_PROGRESSIVE_SUPPORTED
188 int * last_bitpos_ptr;
189 int last_bitpos[MAX_COMPONENTS][DCTSIZE2];
190 /* -1 until that coefficient has been seen; then last Al for it */
191 #endif
192
193 if (cinfo->num_scans <= 0)
194 ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, 0);
195
196 /* For sequential JPEG, all scans must have Ss=0, Se=DCTSIZE2-1;
197 * for progressive JPEG, no scan can have this.
198 */
199 scanptr = cinfo->scan_info;
200 if (scanptr->Ss != 0 || scanptr->Se != DCTSIZE2-1) {
201 #ifdef C_PROGRESSIVE_SUPPORTED
202 cinfo->progressive_mode = TRUE;
203 last_bitpos_ptr = & last_bitpos[0][0];
204 for (ci = 0; ci < cinfo->num_components; ci++)
205 for (coefi = 0; coefi < DCTSIZE2; coefi++)
206 *last_bitpos_ptr++ = -1;
207 #else
208 ERREXIT(cinfo, JERR_NOT_COMPILED);
209 #endif
210 } else {
211 cinfo->progressive_mode = FALSE;
212 for (ci = 0; ci < cinfo->num_components; ci++)
213 component_sent[ci] = FALSE;
214 }
215
216 for (scanno = 1; scanno <= cinfo->num_scans; scanptr++, scanno++) {
217 /* Validate component indexes */
218 ncomps = scanptr->comps_in_scan;
219 if (ncomps <= 0 || ncomps > MAX_COMPS_IN_SCAN)
220 ERREXIT2(cinfo, JERR_COMPONENT_COUNT, ncomps, MAX_COMPS_IN_SCAN);
221 for (ci = 0; ci < ncomps; ci++) {
222 thisi = scanptr->component_index[ci];
223 if (thisi < 0 || thisi >= cinfo->num_components)
224 ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, scanno);
225 /* Components must appear in SOF order within each scan */
226 if (ci > 0 && thisi <= scanptr->component_index[ci-1])
227 ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, scanno);
228 }
229 /* Validate progression parameters */
230 Ss = scanptr->Ss;
231 Se = scanptr->Se;
232 Ah = scanptr->Ah;
233 Al = scanptr->Al;
234 if (cinfo->progressive_mode) {
235 #ifdef C_PROGRESSIVE_SUPPORTED
236 /* The JPEG spec simply gives the ranges 0..13 for Ah and Al, but that
237 * seems wrong: the upper bound ought to depend on data precision.
238 * Perhaps they really meant 0..N+1 for N-bit precision.
239 * Here we allow 0..10 for 8-bit data; Al larger than 10 results in
240 * out-of-range reconstructed DC values during the first DC scan,
241 * which might cause problems for some decoders.
242 */
243 if (Ss < 0 || Ss >= DCTSIZE2 || Se < Ss || Se >= DCTSIZE2 ||
244 Ah < 0 || Ah > (cinfo->data_precision > 8 ? 13 : 10) ||
245 Al < 0 || Al > (cinfo->data_precision > 8 ? 13 : 10))
246 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
247 if (Ss == 0) {
248 if (Se != 0) /* DC and AC together not OK */
249 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
250 } else {
251 if (ncomps != 1) /* AC scans must be for only one component */
252 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
253 }
254 for (ci = 0; ci < ncomps; ci++) {
255 last_bitpos_ptr = & last_bitpos[scanptr->component_index[ci]][0];
256 if (Ss != 0 && last_bitpos_ptr[0] < 0) /* AC without prior DC scan */
257 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
258 for (coefi = Ss; coefi <= Se; coefi++) {
259 if (last_bitpos_ptr[coefi] < 0) {
260 /* first scan of this coefficient */
261 if (Ah != 0)
262 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
263 } else {
264 /* not first scan */
265 if (Ah != last_bitpos_ptr[coefi] || Al != Ah-1)
266 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
267 }
268 last_bitpos_ptr[coefi] = Al;
269 }
270 }
271 #endif
272 } else {
273 /* For sequential JPEG, all progression parameters must be these: */
274 if (Ss != 0 || Se != DCTSIZE2-1 || Ah != 0 || Al != 0)
275 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
276 /* Make sure components are not sent twice */
277 for (ci = 0; ci < ncomps; ci++) {
278 thisi = scanptr->component_index[ci];
279 if (component_sent[thisi])
280 ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, scanno);
281 component_sent[thisi] = TRUE;
282 }
283 }
284 }
285
286 /* Now verify that everything got sent. */
287 if (cinfo->progressive_mode) {
288 #ifdef C_PROGRESSIVE_SUPPORTED
289 /* For progressive mode, we only check that at least some DC data
290 * got sent for each component; the spec does not require that all bits
291 * of all coefficients be transmitted. Would it be wiser to enforce
292 * transmission of all coefficient bits??
293 */
294 for (ci = 0; ci < cinfo->num_components; ci++) {
295 if (last_bitpos[ci][0] < 0)
296 ERREXIT(cinfo, JERR_MISSING_DATA);
297 }
298 #endif
299 } else {
300 for (ci = 0; ci < cinfo->num_components; ci++) {
301 if (! component_sent[ci])
302 ERREXIT(cinfo, JERR_MISSING_DATA);
303 }
304 }
305 }
306
307
308 LOCAL(void)
309 reduce_script (j_compress_ptr cinfo)
310 /* Adapt scan script for use with reduced block size;
311 * assume that script has been validated before.
312 */
313 {
314 jpeg_scan_info * scanptr;
315 int idxout, idxin;
316
317 /* Circumvent const declaration for this function */
318 scanptr = (jpeg_scan_info *) cinfo->scan_info;
319 idxout = 0;
320
321 for (idxin = 0; idxin < cinfo->num_scans; idxin++) {
322 /* After skipping, idxout becomes smaller than idxin */
323 if (idxin != idxout)
324 /* Copy rest of data;
325 * note we stay in given chunk of allocated memory.
326 */
327 scanptr[idxout] = scanptr[idxin];
328 if (scanptr[idxout].Ss > cinfo->lim_Se)
329 /* Entire scan out of range - skip this entry */
330 continue;
331 if (scanptr[idxout].Se > cinfo->lim_Se)
332 /* Limit scan to end of block */
333 scanptr[idxout].Se = cinfo->lim_Se;
334 idxout++;
335 }
336
337 cinfo->num_scans = idxout;
338 }
339
340 #endif /* C_MULTISCAN_FILES_SUPPORTED */
341
342
343 LOCAL(void)
344 select_scan_parameters (j_compress_ptr cinfo)
345 /* Set up the scan parameters for the current scan */
346 {
347 int ci;
348
349 #ifdef C_MULTISCAN_FILES_SUPPORTED
350 if (cinfo->scan_info != NULL) {
351 /* Prepare for current scan --- the script is already validated */
352 my_master_ptr master = (my_master_ptr) cinfo->master;
353 const jpeg_scan_info * scanptr = cinfo->scan_info + master->scan_number;
354
355 cinfo->comps_in_scan = scanptr->comps_in_scan;
356 for (ci = 0; ci < scanptr->comps_in_scan; ci++) {
357 cinfo->cur_comp_info[ci] =
358 &cinfo->comp_info[scanptr->component_index[ci]];
359 }
360 if (cinfo->progressive_mode) {
361 cinfo->Ss = scanptr->Ss;
362 cinfo->Se = scanptr->Se;
363 cinfo->Ah = scanptr->Ah;
364 cinfo->Al = scanptr->Al;
365 return;
366 }
367 }
368 else
369 #endif
370 {
371 /* Prepare for single sequential-JPEG scan containing all components */
372 if (cinfo->num_components > MAX_COMPS_IN_SCAN)
373 ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components,
374 MAX_COMPS_IN_SCAN);
375 cinfo->comps_in_scan = cinfo->num_components;
376 for (ci = 0; ci < cinfo->num_components; ci++) {
377 cinfo->cur_comp_info[ci] = &cinfo->comp_info[ci];
378 }
379 }
380 cinfo->Ss = 0;
381 cinfo->Se = cinfo->block_size * cinfo->block_size - 1;
382 cinfo->Ah = 0;
383 cinfo->Al = 0;
384 }
385
386
387 LOCAL(void)
388 per_scan_setup (j_compress_ptr cinfo)
389 /* Do computations that are needed before processing a JPEG scan */
390 /* cinfo->comps_in_scan and cinfo->cur_comp_info[] are already set */
391 {
392 int ci, mcublks, tmp;
393 jpeg_component_info *compptr;
394
395 if (cinfo->comps_in_scan == 1) {
396
397 /* Noninterleaved (single-component) scan */
398 compptr = cinfo->cur_comp_info[0];
399
400 /* Overall image size in MCUs */
401 cinfo->MCUs_per_row = compptr->width_in_blocks;
402 cinfo->MCU_rows_in_scan = compptr->height_in_blocks;
403
404 /* For noninterleaved scan, always one block per MCU */
405 compptr->MCU_width = 1;
406 compptr->MCU_height = 1;
407 compptr->MCU_blocks = 1;
408 compptr->MCU_sample_width = compptr->DCT_h_scaled_size;
409 compptr->last_col_width = 1;
410 /* For noninterleaved scans, it is convenient to define last_row_height
411 * as the number of block rows present in the last iMCU row.
412 */
413 tmp = (int) (compptr->height_in_blocks % compptr->v_samp_factor);
414 if (tmp == 0) tmp = compptr->v_samp_factor;
415 compptr->last_row_height = tmp;
416
417 /* Prepare array describing MCU composition */
418 cinfo->blocks_in_MCU = 1;
419 cinfo->MCU_membership[0] = 0;
420
421 } else {
422
423 /* Interleaved (multi-component) scan */
424 if (cinfo->comps_in_scan <= 0 || cinfo->comps_in_scan > MAX_COMPS_IN_SCAN)
425 ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->comps_in_scan,
426 MAX_COMPS_IN_SCAN);
427
428 /* Overall image size in MCUs */
429 cinfo->MCUs_per_row = (JDIMENSION)
430 jdiv_round_up((long) cinfo->jpeg_width,
431 (long) (cinfo->max_h_samp_factor * cinfo->block_size));
432 cinfo->MCU_rows_in_scan = cinfo->total_iMCU_rows;
433
434 cinfo->blocks_in_MCU = 0;
435
436 for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
437 compptr = cinfo->cur_comp_info[ci];
438 /* Sampling factors give # of blocks of component in each MCU */
439 compptr->MCU_width = compptr->h_samp_factor;
440 compptr->MCU_height = compptr->v_samp_factor;
441 compptr->MCU_blocks = compptr->MCU_width * compptr->MCU_height;
442 compptr->MCU_sample_width = compptr->MCU_width * compptr->DCT_h_scaled_size;
443 /* Figure number of non-dummy blocks in last MCU column & row */
444 tmp = (int) (compptr->width_in_blocks % compptr->MCU_width);
445 if (tmp == 0) tmp = compptr->MCU_width;
446 compptr->last_col_width = tmp;
447 tmp = (int) (compptr->height_in_blocks % compptr->MCU_height);
448 if (tmp == 0) tmp = compptr->MCU_height;
449 compptr->last_row_height = tmp;
450 /* Prepare array describing MCU composition */
451 mcublks = compptr->MCU_blocks;
452 if (cinfo->blocks_in_MCU + mcublks > C_MAX_BLOCKS_IN_MCU)
453 ERREXIT(cinfo, JERR_BAD_MCU_SIZE);
454 while (mcublks-- > 0) {
455 cinfo->MCU_membership[cinfo->blocks_in_MCU++] = ci;
456 }
457 }
458
459 }
460
461 /* Convert restart specified in rows to actual MCU count. */
462 /* Note that count must fit in 16 bits, so we provide limiting. */
463 if (cinfo->restart_in_rows > 0) {
464 long nominal = (long) cinfo->restart_in_rows * (long) cinfo->MCUs_per_row;
465 cinfo->restart_interval = (unsigned int) MIN(nominal, 65535L);
466 }
467 }
468
469
470 /*
471 * Per-pass setup.
472 * This is called at the beginning of each pass. We determine which modules
473 * will be active during this pass and give them appropriate start_pass calls.
474 * We also set is_last_pass to indicate whether any more passes will be
475 * required.
476 */
477
478 METHODDEF(void)
479 prepare_for_pass (j_compress_ptr cinfo)
480 {
481 my_master_ptr master = (my_master_ptr) cinfo->master;
482
483 switch (master->pass_type) {
484 case main_pass:
485 /* Initial pass: will collect input data, and do either Huffman
486 * optimization or data output for the first scan.
487 */
488 select_scan_parameters(cinfo);
489 per_scan_setup(cinfo);
490 if (! cinfo->raw_data_in) {
491 (*cinfo->cconvert->start_pass) (cinfo);
492 (*cinfo->downsample->start_pass) (cinfo);
493 (*cinfo->prep->start_pass) (cinfo, JBUF_PASS_THRU);
494 }
495 (*cinfo->fdct->start_pass) (cinfo);
496 (*cinfo->entropy->start_pass) (cinfo, cinfo->optimize_coding);
497 (*cinfo->coef->start_pass) (cinfo,
498 (master->total_passes > 1 ?
499 JBUF_SAVE_AND_PASS : JBUF_PASS_THRU));
500 (*cinfo->main->start_pass) (cinfo, JBUF_PASS_THRU);
501 if (cinfo->optimize_coding) {
502 /* No immediate data output; postpone writing frame/scan headers */
503 master->pub.call_pass_startup = FALSE;
504 } else {
505 /* Will write frame/scan headers at first jpeg_write_scanlines call */
506 master->pub.call_pass_startup = TRUE;
507 }
508 break;
509 #ifdef ENTROPY_OPT_SUPPORTED
510 case huff_opt_pass:
511 /* Do Huffman optimization for a scan after the first one. */
512 select_scan_parameters(cinfo);
513 per_scan_setup(cinfo);
514 if (cinfo->Ss != 0 || cinfo->Ah == 0) {
515 (*cinfo->entropy->start_pass) (cinfo, TRUE);
516 (*cinfo->coef->start_pass) (cinfo, JBUF_CRANK_DEST);
517 master->pub.call_pass_startup = FALSE;
518 break;
519 }
520 /* Special case: Huffman DC refinement scans need no Huffman table
521 * and therefore we can skip the optimization pass for them.
522 */
523 master->pass_type = output_pass;
524 master->pass_number++;
525 /*FALLTHROUGH*/
526 #endif
527 case output_pass:
528 /* Do a data-output pass. */
529 /* We need not repeat per-scan setup if prior optimization pass did it. */
530 if (! cinfo->optimize_coding) {
531 select_scan_parameters(cinfo);
532 per_scan_setup(cinfo);
533 }
534 (*cinfo->entropy->start_pass) (cinfo, FALSE);
535 (*cinfo->coef->start_pass) (cinfo, JBUF_CRANK_DEST);
536 /* We emit frame/scan headers now */
537 if (master->scan_number == 0)
538 (*cinfo->marker->write_frame_header) (cinfo);
539 (*cinfo->marker->write_scan_header) (cinfo);
540 master->pub.call_pass_startup = FALSE;
541 break;
542 default:
543 ERREXIT(cinfo, JERR_NOT_COMPILED);
544 }
545
546 master->pub.is_last_pass = (master->pass_number == master->total_passes-1);
547
548 /* Set up progress monitor's pass info if present */
549 if (cinfo->progress != NULL) {
550 cinfo->progress->completed_passes = master->pass_number;
551 cinfo->progress->total_passes = master->total_passes;
552 }
553 }
554
555
556 /*
557 * Special start-of-pass hook.
558 * This is called by jpeg_write_scanlines if call_pass_startup is TRUE.
559 * In single-pass processing, we need this hook because we don't want to
560 * write frame/scan headers during jpeg_start_compress; we want to let the
561 * application write COM markers etc. between jpeg_start_compress and the
562 * jpeg_write_scanlines loop.
563 * In multi-pass processing, this routine is not used.
564 */
565
566 METHODDEF(void)
567 pass_startup (j_compress_ptr cinfo)
568 {
569 cinfo->master->call_pass_startup = FALSE; /* reset flag so call only once */
570
571 (*cinfo->marker->write_frame_header) (cinfo);
572 (*cinfo->marker->write_scan_header) (cinfo);
573 }
574
575
576 /*
577 * Finish up at end of pass.
578 */
579
580 METHODDEF(void)
581 finish_pass_master (j_compress_ptr cinfo)
582 {
583 my_master_ptr master = (my_master_ptr) cinfo->master;
584
585 /* The entropy coder always needs an end-of-pass call,
586 * either to analyze statistics or to flush its output buffer.
587 */
588 (*cinfo->entropy->finish_pass) (cinfo);
589
590 /* Update state for next pass */
591 switch (master->pass_type) {
592 case main_pass:
593 /* next pass is either output of scan 0 (after optimization)
594 * or output of scan 1 (if no optimization).
595 */
596 master->pass_type = output_pass;
597 if (! cinfo->optimize_coding)
598 master->scan_number++;
599 break;
600 case huff_opt_pass:
601 /* next pass is always output of current scan */
602 master->pass_type = output_pass;
603 break;
604 case output_pass:
605 /* next pass is either optimization or output of next scan */
606 if (cinfo->optimize_coding)
607 master->pass_type = huff_opt_pass;
608 master->scan_number++;
609 break;
610 }
611
612 master->pass_number++;
613 }
614
615
616 /*
617 * Initialize master compression control.
618 */
619
620 GLOBAL(void)
621 jinit_c_master_control (j_compress_ptr cinfo, boolean transcode_only)
622 {
623 my_master_ptr master;
624
625 master = (my_master_ptr) (*cinfo->mem->alloc_small)
626 ((j_common_ptr) cinfo, JPOOL_IMAGE, SIZEOF(my_comp_master));
627 cinfo->master = &master->pub;
628 master->pub.prepare_for_pass = prepare_for_pass;
629 master->pub.pass_startup = pass_startup;
630 master->pub.finish_pass = finish_pass_master;
631 master->pub.is_last_pass = FALSE;
632
633 /* Validate parameters, determine derived values */
634 initial_setup(cinfo);
635
636 if (cinfo->scan_info != NULL) {
637 #ifdef C_MULTISCAN_FILES_SUPPORTED
638 validate_script(cinfo);
639 if (cinfo->block_size < DCTSIZE)
640 reduce_script(cinfo);
641 #else
642 ERREXIT(cinfo, JERR_NOT_COMPILED);
643 #endif
644 } else {
645 cinfo->progressive_mode = FALSE;
646 cinfo->num_scans = 1;
647 }
648
649 if (cinfo->optimize_coding)
650 cinfo->arith_code = FALSE; /* disable arithmetic coding */
651 else if (! cinfo->arith_code &&
652 (cinfo->progressive_mode ||
653 (cinfo->block_size > 1 && cinfo->block_size < DCTSIZE)))
654 /* TEMPORARY HACK ??? */
655 /* assume default tables no good for progressive or reduced AC mode */
656 cinfo->optimize_coding = TRUE; /* force Huffman optimization */
657
658 /* Initialize my private state */
659 if (transcode_only) {
660 /* no main pass in transcoding */
661 if (cinfo->optimize_coding)
662 master->pass_type = huff_opt_pass;
663 else
664 master->pass_type = output_pass;
665 } else {
666 /* for normal compression, first pass is always this type: */
667 master->pass_type = main_pass;
668 }
669 master->scan_number = 0;
670 master->pass_number = 0;
671 if (cinfo->optimize_coding)
672 master->total_passes = cinfo->num_scans * 2;
673 else
674 master->total_passes = cinfo->num_scans;
675 }