Bug 1835867 - Part 2: Fold requested heap and per-kind nursery allocation allowed...
[gecko.git] / media / libjpeg / jcmaster.c
blobb821710ac308ffc7758e97104ad84451729ef9bc
1 /*
2 * jcmaster.c
4 * This file was part of the Independent JPEG Group's software:
5 * Copyright (C) 1991-1997, Thomas G. Lane.
6 * Modified 2003-2010 by Guido Vollbeding.
7 * libjpeg-turbo Modifications:
8 * Copyright (C) 2010, 2016, 2018, D. R. Commander.
9 * For conditions of distribution and use, see the accompanying README.ijg
10 * file.
12 * This file contains master control logic for the JPEG compressor.
13 * These routines are concerned with parameter validation, initial setup,
14 * and inter-pass control (determining the number of passes and the work
15 * to be done in each pass).
18 #define JPEG_INTERNALS
19 #include "jinclude.h"
20 #include "jpeglib.h"
21 #include "jpegcomp.h"
24 /* Private state */
26 typedef enum {
27 main_pass, /* input data, also do first output step */
28 huff_opt_pass, /* Huffman code optimization pass */
29 output_pass /* data output pass */
30 } c_pass_type;
32 typedef struct {
33 struct jpeg_comp_master pub; /* public fields */
35 c_pass_type pass_type; /* the type of the current pass */
37 int pass_number; /* # of passes completed */
38 int total_passes; /* total # of passes needed */
40 int scan_number; /* current index in scan_info[] */
43 * This is here so we can add libjpeg-turbo version/build information to the
44 * global string table without introducing a new global symbol. Adding this
45 * information to the global string table allows one to examine a binary
46 * object and determine which version of libjpeg-turbo it was built from or
47 * linked against.
49 const char *jpeg_version;
51 } my_comp_master;
53 typedef my_comp_master *my_master_ptr;
57 * Support routines that do various essential calculations.
60 #if JPEG_LIB_VERSION >= 70
62 * Compute JPEG image dimensions and related values.
63 * NOTE: this is exported for possible use by application.
64 * Hence it mustn't do anything that can't be done twice.
67 GLOBAL(void)
68 jpeg_calc_jpeg_dimensions(j_compress_ptr cinfo)
69 /* Do computations that are needed before master selection phase */
71 /* Hardwire it to "no scaling" */
72 cinfo->jpeg_width = cinfo->image_width;
73 cinfo->jpeg_height = cinfo->image_height;
74 cinfo->min_DCT_h_scaled_size = DCTSIZE;
75 cinfo->min_DCT_v_scaled_size = DCTSIZE;
77 #endif
80 LOCAL(void)
81 initial_setup(j_compress_ptr cinfo, boolean transcode_only)
82 /* Do computations that are needed before master selection phase */
84 int ci;
85 jpeg_component_info *compptr;
86 long samplesperrow;
87 JDIMENSION jd_samplesperrow;
89 #if JPEG_LIB_VERSION >= 70
90 #if JPEG_LIB_VERSION >= 80
91 if (!transcode_only)
92 #endif
93 jpeg_calc_jpeg_dimensions(cinfo);
94 #endif
96 /* Sanity check on image dimensions */
97 if (cinfo->_jpeg_height <= 0 || cinfo->_jpeg_width <= 0 ||
98 cinfo->num_components <= 0 || cinfo->input_components <= 0)
99 ERREXIT(cinfo, JERR_EMPTY_IMAGE);
101 /* Make sure image isn't bigger than I can handle */
102 if ((long)cinfo->_jpeg_height > (long)JPEG_MAX_DIMENSION ||
103 (long)cinfo->_jpeg_width > (long)JPEG_MAX_DIMENSION)
104 ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int)JPEG_MAX_DIMENSION);
106 /* Width of an input scanline must be representable as JDIMENSION. */
107 samplesperrow = (long)cinfo->image_width * (long)cinfo->input_components;
108 jd_samplesperrow = (JDIMENSION)samplesperrow;
109 if ((long)jd_samplesperrow != samplesperrow)
110 ERREXIT(cinfo, JERR_WIDTH_OVERFLOW);
112 /* For now, precision must match compiled-in value... */
113 if (cinfo->data_precision != BITS_IN_JSAMPLE)
114 ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision);
116 /* Check that number of components won't exceed internal array sizes */
117 if (cinfo->num_components > MAX_COMPONENTS)
118 ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components,
119 MAX_COMPONENTS);
121 /* Compute maximum sampling factors; check factor validity */
122 cinfo->max_h_samp_factor = 1;
123 cinfo->max_v_samp_factor = 1;
124 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
125 ci++, compptr++) {
126 if (compptr->h_samp_factor <= 0 ||
127 compptr->h_samp_factor > MAX_SAMP_FACTOR ||
128 compptr->v_samp_factor <= 0 ||
129 compptr->v_samp_factor > MAX_SAMP_FACTOR)
130 ERREXIT(cinfo, JERR_BAD_SAMPLING);
131 cinfo->max_h_samp_factor = MAX(cinfo->max_h_samp_factor,
132 compptr->h_samp_factor);
133 cinfo->max_v_samp_factor = MAX(cinfo->max_v_samp_factor,
134 compptr->v_samp_factor);
137 /* Compute dimensions of components */
138 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
139 ci++, compptr++) {
140 /* Fill in the correct component_index value; don't rely on application */
141 compptr->component_index = ci;
142 /* For compression, we never do DCT scaling. */
143 #if JPEG_LIB_VERSION >= 70
144 compptr->DCT_h_scaled_size = compptr->DCT_v_scaled_size = DCTSIZE;
145 #else
146 compptr->DCT_scaled_size = DCTSIZE;
147 #endif
148 /* Size in DCT blocks */
149 compptr->width_in_blocks = (JDIMENSION)
150 jdiv_round_up((long)cinfo->_jpeg_width * (long)compptr->h_samp_factor,
151 (long)(cinfo->max_h_samp_factor * DCTSIZE));
152 compptr->height_in_blocks = (JDIMENSION)
153 jdiv_round_up((long)cinfo->_jpeg_height * (long)compptr->v_samp_factor,
154 (long)(cinfo->max_v_samp_factor * DCTSIZE));
155 /* Size in samples */
156 compptr->downsampled_width = (JDIMENSION)
157 jdiv_round_up((long)cinfo->_jpeg_width * (long)compptr->h_samp_factor,
158 (long)cinfo->max_h_samp_factor);
159 compptr->downsampled_height = (JDIMENSION)
160 jdiv_round_up((long)cinfo->_jpeg_height * (long)compptr->v_samp_factor,
161 (long)cinfo->max_v_samp_factor);
162 /* Mark component needed (this flag isn't actually used for compression) */
163 compptr->component_needed = TRUE;
166 /* Compute number of fully interleaved MCU rows (number of times that
167 * main controller will call coefficient controller).
169 cinfo->total_iMCU_rows = (JDIMENSION)
170 jdiv_round_up((long)cinfo->_jpeg_height,
171 (long)(cinfo->max_v_samp_factor * DCTSIZE));
175 #ifdef C_MULTISCAN_FILES_SUPPORTED
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.
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
193 if (cinfo->num_scans <= 0)
194 ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, 0);
196 /* For sequential JPEG, all scans must have Ss=0, Se=DCTSIZE2-1;
197 * for progressive JPEG, no scan can have this.
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;
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);
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 /* Rec. ITU-T T.81 | ISO/IEC 10918-1 simply gives the ranges 0..13 for Ah
237 * and Al, but that seems wrong: the upper bound ought to depend on data
238 * precision. 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.
243 #if BITS_IN_JSAMPLE == 8
244 #define MAX_AH_AL 10
245 #else
246 #define MAX_AH_AL 13
247 #endif
248 if (Ss < 0 || Ss >= DCTSIZE2 || Se < Ss || Se >= DCTSIZE2 ||
249 Ah < 0 || Ah > MAX_AH_AL || Al < 0 || Al > MAX_AH_AL)
250 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
251 if (Ss == 0) {
252 if (Se != 0) /* DC and AC together not OK */
253 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
254 } else {
255 if (ncomps != 1) /* AC scans must be for only one component */
256 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
258 for (ci = 0; ci < ncomps; ci++) {
259 last_bitpos_ptr = &last_bitpos[scanptr->component_index[ci]][0];
260 if (Ss != 0 && last_bitpos_ptr[0] < 0) /* AC without prior DC scan */
261 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
262 for (coefi = Ss; coefi <= Se; coefi++) {
263 if (last_bitpos_ptr[coefi] < 0) {
264 /* first scan of this coefficient */
265 if (Ah != 0)
266 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
267 } else {
268 /* not first scan */
269 if (Ah != last_bitpos_ptr[coefi] || Al != Ah - 1)
270 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
272 last_bitpos_ptr[coefi] = Al;
275 #endif
276 } else {
277 /* For sequential JPEG, all progression parameters must be these: */
278 if (Ss != 0 || Se != DCTSIZE2 - 1 || Ah != 0 || Al != 0)
279 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
280 /* Make sure components are not sent twice */
281 for (ci = 0; ci < ncomps; ci++) {
282 thisi = scanptr->component_index[ci];
283 if (component_sent[thisi])
284 ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, scanno);
285 component_sent[thisi] = TRUE;
290 /* Now verify that everything got sent. */
291 if (cinfo->progressive_mode) {
292 #ifdef C_PROGRESSIVE_SUPPORTED
293 /* For progressive mode, we only check that at least some DC data
294 * got sent for each component; the spec does not require that all bits
295 * of all coefficients be transmitted. Would it be wiser to enforce
296 * transmission of all coefficient bits??
298 for (ci = 0; ci < cinfo->num_components; ci++) {
299 if (last_bitpos[ci][0] < 0)
300 ERREXIT(cinfo, JERR_MISSING_DATA);
302 #endif
303 } else {
304 for (ci = 0; ci < cinfo->num_components; ci++) {
305 if (!component_sent[ci])
306 ERREXIT(cinfo, JERR_MISSING_DATA);
311 #endif /* C_MULTISCAN_FILES_SUPPORTED */
314 LOCAL(void)
315 select_scan_parameters(j_compress_ptr cinfo)
316 /* Set up the scan parameters for the current scan */
318 int ci;
320 #ifdef C_MULTISCAN_FILES_SUPPORTED
321 if (cinfo->scan_info != NULL) {
322 /* Prepare for current scan --- the script is already validated */
323 my_master_ptr master = (my_master_ptr)cinfo->master;
324 const jpeg_scan_info *scanptr = cinfo->scan_info + master->scan_number;
326 cinfo->comps_in_scan = scanptr->comps_in_scan;
327 for (ci = 0; ci < scanptr->comps_in_scan; ci++) {
328 cinfo->cur_comp_info[ci] =
329 &cinfo->comp_info[scanptr->component_index[ci]];
331 cinfo->Ss = scanptr->Ss;
332 cinfo->Se = scanptr->Se;
333 cinfo->Ah = scanptr->Ah;
334 cinfo->Al = scanptr->Al;
335 } else
336 #endif
338 /* Prepare for single sequential-JPEG scan containing all components */
339 if (cinfo->num_components > MAX_COMPS_IN_SCAN)
340 ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components,
341 MAX_COMPS_IN_SCAN);
342 cinfo->comps_in_scan = cinfo->num_components;
343 for (ci = 0; ci < cinfo->num_components; ci++) {
344 cinfo->cur_comp_info[ci] = &cinfo->comp_info[ci];
346 cinfo->Ss = 0;
347 cinfo->Se = DCTSIZE2 - 1;
348 cinfo->Ah = 0;
349 cinfo->Al = 0;
354 LOCAL(void)
355 per_scan_setup(j_compress_ptr cinfo)
356 /* Do computations that are needed before processing a JPEG scan */
357 /* cinfo->comps_in_scan and cinfo->cur_comp_info[] are already set */
359 int ci, mcublks, tmp;
360 jpeg_component_info *compptr;
362 if (cinfo->comps_in_scan == 1) {
364 /* Noninterleaved (single-component) scan */
365 compptr = cinfo->cur_comp_info[0];
367 /* Overall image size in MCUs */
368 cinfo->MCUs_per_row = compptr->width_in_blocks;
369 cinfo->MCU_rows_in_scan = compptr->height_in_blocks;
371 /* For noninterleaved scan, always one block per MCU */
372 compptr->MCU_width = 1;
373 compptr->MCU_height = 1;
374 compptr->MCU_blocks = 1;
375 compptr->MCU_sample_width = DCTSIZE;
376 compptr->last_col_width = 1;
377 /* For noninterleaved scans, it is convenient to define last_row_height
378 * as the number of block rows present in the last iMCU row.
380 tmp = (int)(compptr->height_in_blocks % compptr->v_samp_factor);
381 if (tmp == 0) tmp = compptr->v_samp_factor;
382 compptr->last_row_height = tmp;
384 /* Prepare array describing MCU composition */
385 cinfo->blocks_in_MCU = 1;
386 cinfo->MCU_membership[0] = 0;
388 } else {
390 /* Interleaved (multi-component) scan */
391 if (cinfo->comps_in_scan <= 0 || cinfo->comps_in_scan > MAX_COMPS_IN_SCAN)
392 ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->comps_in_scan,
393 MAX_COMPS_IN_SCAN);
395 /* Overall image size in MCUs */
396 cinfo->MCUs_per_row = (JDIMENSION)
397 jdiv_round_up((long)cinfo->_jpeg_width,
398 (long)(cinfo->max_h_samp_factor * DCTSIZE));
399 cinfo->MCU_rows_in_scan = (JDIMENSION)
400 jdiv_round_up((long)cinfo->_jpeg_height,
401 (long)(cinfo->max_v_samp_factor * DCTSIZE));
403 cinfo->blocks_in_MCU = 0;
405 for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
406 compptr = cinfo->cur_comp_info[ci];
407 /* Sampling factors give # of blocks of component in each MCU */
408 compptr->MCU_width = compptr->h_samp_factor;
409 compptr->MCU_height = compptr->v_samp_factor;
410 compptr->MCU_blocks = compptr->MCU_width * compptr->MCU_height;
411 compptr->MCU_sample_width = compptr->MCU_width * DCTSIZE;
412 /* Figure number of non-dummy blocks in last MCU column & row */
413 tmp = (int)(compptr->width_in_blocks % compptr->MCU_width);
414 if (tmp == 0) tmp = compptr->MCU_width;
415 compptr->last_col_width = tmp;
416 tmp = (int)(compptr->height_in_blocks % compptr->MCU_height);
417 if (tmp == 0) tmp = compptr->MCU_height;
418 compptr->last_row_height = tmp;
419 /* Prepare array describing MCU composition */
420 mcublks = compptr->MCU_blocks;
421 if (cinfo->blocks_in_MCU + mcublks > C_MAX_BLOCKS_IN_MCU)
422 ERREXIT(cinfo, JERR_BAD_MCU_SIZE);
423 while (mcublks-- > 0) {
424 cinfo->MCU_membership[cinfo->blocks_in_MCU++] = ci;
430 /* Convert restart specified in rows to actual MCU count. */
431 /* Note that count must fit in 16 bits, so we provide limiting. */
432 if (cinfo->restart_in_rows > 0) {
433 long nominal = (long)cinfo->restart_in_rows * (long)cinfo->MCUs_per_row;
434 cinfo->restart_interval = (unsigned int)MIN(nominal, 65535L);
440 * Per-pass setup.
441 * This is called at the beginning of each pass. We determine which modules
442 * will be active during this pass and give them appropriate start_pass calls.
443 * We also set is_last_pass to indicate whether any more passes will be
444 * required.
447 METHODDEF(void)
448 prepare_for_pass(j_compress_ptr cinfo)
450 my_master_ptr master = (my_master_ptr)cinfo->master;
452 switch (master->pass_type) {
453 case main_pass:
454 /* Initial pass: will collect input data, and do either Huffman
455 * optimization or data output for the first scan.
457 select_scan_parameters(cinfo);
458 per_scan_setup(cinfo);
459 if (!cinfo->raw_data_in) {
460 (*cinfo->cconvert->start_pass) (cinfo);
461 (*cinfo->downsample->start_pass) (cinfo);
462 (*cinfo->prep->start_pass) (cinfo, JBUF_PASS_THRU);
464 (*cinfo->fdct->start_pass) (cinfo);
465 (*cinfo->entropy->start_pass) (cinfo, cinfo->optimize_coding);
466 (*cinfo->coef->start_pass) (cinfo,
467 (master->total_passes > 1 ?
468 JBUF_SAVE_AND_PASS : JBUF_PASS_THRU));
469 (*cinfo->main->start_pass) (cinfo, JBUF_PASS_THRU);
470 if (cinfo->optimize_coding) {
471 /* No immediate data output; postpone writing frame/scan headers */
472 master->pub.call_pass_startup = FALSE;
473 } else {
474 /* Will write frame/scan headers at first jpeg_write_scanlines call */
475 master->pub.call_pass_startup = TRUE;
477 break;
478 #ifdef ENTROPY_OPT_SUPPORTED
479 case huff_opt_pass:
480 /* Do Huffman optimization for a scan after the first one. */
481 select_scan_parameters(cinfo);
482 per_scan_setup(cinfo);
483 if (cinfo->Ss != 0 || cinfo->Ah == 0 || cinfo->arith_code) {
484 (*cinfo->entropy->start_pass) (cinfo, TRUE);
485 (*cinfo->coef->start_pass) (cinfo, JBUF_CRANK_DEST);
486 master->pub.call_pass_startup = FALSE;
487 break;
489 /* Special case: Huffman DC refinement scans need no Huffman table
490 * and therefore we can skip the optimization pass for them.
492 master->pass_type = output_pass;
493 master->pass_number++;
494 #endif
495 FALLTHROUGH /*FALLTHROUGH*/
496 case output_pass:
497 /* Do a data-output pass. */
498 /* We need not repeat per-scan setup if prior optimization pass did it. */
499 if (!cinfo->optimize_coding) {
500 select_scan_parameters(cinfo);
501 per_scan_setup(cinfo);
503 (*cinfo->entropy->start_pass) (cinfo, FALSE);
504 (*cinfo->coef->start_pass) (cinfo, JBUF_CRANK_DEST);
505 /* We emit frame/scan headers now */
506 if (master->scan_number == 0)
507 (*cinfo->marker->write_frame_header) (cinfo);
508 (*cinfo->marker->write_scan_header) (cinfo);
509 master->pub.call_pass_startup = FALSE;
510 break;
511 default:
512 ERREXIT(cinfo, JERR_NOT_COMPILED);
515 master->pub.is_last_pass = (master->pass_number == master->total_passes - 1);
517 /* Set up progress monitor's pass info if present */
518 if (cinfo->progress != NULL) {
519 cinfo->progress->completed_passes = master->pass_number;
520 cinfo->progress->total_passes = master->total_passes;
526 * Special start-of-pass hook.
527 * This is called by jpeg_write_scanlines if call_pass_startup is TRUE.
528 * In single-pass processing, we need this hook because we don't want to
529 * write frame/scan headers during jpeg_start_compress; we want to let the
530 * application write COM markers etc. between jpeg_start_compress and the
531 * jpeg_write_scanlines loop.
532 * In multi-pass processing, this routine is not used.
535 METHODDEF(void)
536 pass_startup(j_compress_ptr cinfo)
538 cinfo->master->call_pass_startup = FALSE; /* reset flag so call only once */
540 (*cinfo->marker->write_frame_header) (cinfo);
541 (*cinfo->marker->write_scan_header) (cinfo);
546 * Finish up at end of pass.
549 METHODDEF(void)
550 finish_pass_master(j_compress_ptr cinfo)
552 my_master_ptr master = (my_master_ptr)cinfo->master;
554 /* The entropy coder always needs an end-of-pass call,
555 * either to analyze statistics or to flush its output buffer.
557 (*cinfo->entropy->finish_pass) (cinfo);
559 /* Update state for next pass */
560 switch (master->pass_type) {
561 case main_pass:
562 /* next pass is either output of scan 0 (after optimization)
563 * or output of scan 1 (if no optimization).
565 master->pass_type = output_pass;
566 if (!cinfo->optimize_coding)
567 master->scan_number++;
568 break;
569 case huff_opt_pass:
570 /* next pass is always output of current scan */
571 master->pass_type = output_pass;
572 break;
573 case output_pass:
574 /* next pass is either optimization or output of next scan */
575 if (cinfo->optimize_coding)
576 master->pass_type = huff_opt_pass;
577 master->scan_number++;
578 break;
581 master->pass_number++;
586 * Initialize master compression control.
589 GLOBAL(void)
590 jinit_c_master_control(j_compress_ptr cinfo, boolean transcode_only)
592 my_master_ptr master;
594 master = (my_master_ptr)
595 (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
596 sizeof(my_comp_master));
597 cinfo->master = (struct jpeg_comp_master *)master;
598 master->pub.prepare_for_pass = prepare_for_pass;
599 master->pub.pass_startup = pass_startup;
600 master->pub.finish_pass = finish_pass_master;
601 master->pub.is_last_pass = FALSE;
603 /* Validate parameters, determine derived values */
604 initial_setup(cinfo, transcode_only);
606 if (cinfo->scan_info != NULL) {
607 #ifdef C_MULTISCAN_FILES_SUPPORTED
608 validate_script(cinfo);
609 #else
610 ERREXIT(cinfo, JERR_NOT_COMPILED);
611 #endif
612 } else {
613 cinfo->progressive_mode = FALSE;
614 cinfo->num_scans = 1;
617 if (cinfo->progressive_mode && !cinfo->arith_code) /* TEMPORARY HACK ??? */
618 cinfo->optimize_coding = TRUE; /* assume default tables no good for progressive mode */
620 /* Initialize my private state */
621 if (transcode_only) {
622 /* no main pass in transcoding */
623 if (cinfo->optimize_coding)
624 master->pass_type = huff_opt_pass;
625 else
626 master->pass_type = output_pass;
627 } else {
628 /* for normal compression, first pass is always this type: */
629 master->pass_type = main_pass;
631 master->scan_number = 0;
632 master->pass_number = 0;
633 if (cinfo->optimize_coding)
634 master->total_passes = cinfo->num_scans * 2;
635 else
636 master->total_passes = cinfo->num_scans;
638 master->jpeg_version = PACKAGE_NAME " version " VERSION " (build " BUILD ")";