source: trunk/src/3rdparty/libjpeg/jcmaster.c@ 1163

Last change on this file since 1163 was 846, checked in by Dmitry A. Kuminov, 15 years ago

trunk: Merged in qt 4.7.2 sources from branches/vendor/nokia/qt.
File size: 29.1 KB
Line 
1/*
2 * jcmaster.c
3 *
4 * Copyright (C) 1991-1997, Thomas G. Lane.
5 * Modified 2003-2010 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
22typedef 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
28typedef 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
39typedef my_comp_master * my_master_ptr;
40
41
42/*
43 * Support routines that do various essential calculations.
44 */
45
46/*
47 * Compute JPEG image dimensions and related values.
48 * NOTE: this is exported for possible use by application.
49 * Hence it mustn't do anything that can't be done twice.
50 */
51
52GLOBAL(void)
53jpeg_calc_jpeg_dimensions (j_compress_ptr cinfo)
54/* Do computations that are needed before master selection phase */
55{
56#ifdef DCT_SCALING_SUPPORTED
57
58 /* Compute actual JPEG image dimensions and DCT scaling choices. */
59 if (cinfo->scale_num >= cinfo->scale_denom * 8) {
60 /* Provide 8/1 scaling */
61 cinfo->jpeg_width = cinfo->image_width << 3;
62 cinfo->jpeg_height = cinfo->image_height << 3;
63 cinfo->min_DCT_h_scaled_size = 1;
64 cinfo->min_DCT_v_scaled_size = 1;
65 } else if (cinfo->scale_num >= cinfo->scale_denom * 4) {
66 /* Provide 4/1 scaling */
67 cinfo->jpeg_width = cinfo->image_width << 2;
68 cinfo->jpeg_height = cinfo->image_height << 2;
69 cinfo->min_DCT_h_scaled_size = 2;
70 cinfo->min_DCT_v_scaled_size = 2;
71 } else if (cinfo->scale_num * 3 >= cinfo->scale_denom * 8) {
72 /* Provide 8/3 scaling */
73 cinfo->jpeg_width = (cinfo->image_width << 1) + (JDIMENSION)
74 jdiv_round_up((long) cinfo->image_width * 2, 3L);
75 cinfo->jpeg_height = (cinfo->image_height << 1) + (JDIMENSION)
76 jdiv_round_up((long) cinfo->image_height * 2, 3L);
77 cinfo->min_DCT_h_scaled_size = 3;
78 cinfo->min_DCT_v_scaled_size = 3;
79 } else if (cinfo->scale_num >= cinfo->scale_denom * 2) {
80 /* Provide 2/1 scaling */
81 cinfo->jpeg_width = cinfo->image_width << 1;
82 cinfo->jpeg_height = cinfo->image_height << 1;
83 cinfo->min_DCT_h_scaled_size = 4;
84 cinfo->min_DCT_v_scaled_size = 4;
85 } else if (cinfo->scale_num * 5 >= cinfo->scale_denom * 8) {
86 /* Provide 8/5 scaling */
87 cinfo->jpeg_width = cinfo->image_width + (JDIMENSION)
88 jdiv_round_up((long) cinfo->image_width * 3, 5L);
89 cinfo->jpeg_height = cinfo->image_height + (JDIMENSION)
90 jdiv_round_up((long) cinfo->image_height * 3, 5L);
91 cinfo->min_DCT_h_scaled_size = 5;
92 cinfo->min_DCT_v_scaled_size = 5;
93 } else if (cinfo->scale_num * 3 >= cinfo->scale_denom * 4) {
94 /* Provide 4/3 scaling */
95 cinfo->jpeg_width = cinfo->image_width + (JDIMENSION)
96 jdiv_round_up((long) cinfo->image_width, 3L);
97 cinfo->jpeg_height = cinfo->image_height + (JDIMENSION)
98 jdiv_round_up((long) cinfo->image_height, 3L);
99 cinfo->min_DCT_h_scaled_size = 6;
100 cinfo->min_DCT_v_scaled_size = 6;
101 } else if (cinfo->scale_num * 7 >= cinfo->scale_denom * 8) {
102 /* Provide 8/7 scaling */
103 cinfo->jpeg_width = cinfo->image_width + (JDIMENSION)
104 jdiv_round_up((long) cinfo->image_width, 7L);
105 cinfo->jpeg_height = cinfo->image_height + (JDIMENSION)
106 jdiv_round_up((long) cinfo->image_height, 7L);
107 cinfo->min_DCT_h_scaled_size = 7;
108 cinfo->min_DCT_v_scaled_size = 7;
109 } else if (cinfo->scale_num >= cinfo->scale_denom) {
110 /* Provide 1/1 scaling */
111 cinfo->jpeg_width = cinfo->image_width;
112 cinfo->jpeg_height = cinfo->image_height;
113 cinfo->min_DCT_h_scaled_size = 8;
114 cinfo->min_DCT_v_scaled_size = 8;
115 } else if (cinfo->scale_num * 9 >= cinfo->scale_denom * 8) {
116 /* Provide 8/9 scaling */
117 cinfo->jpeg_width = (JDIMENSION)
118 jdiv_round_up((long) cinfo->image_width * 8, 9L);
119 cinfo->jpeg_height = (JDIMENSION)
120 jdiv_round_up((long) cinfo->image_height * 8, 9L);
121 cinfo->min_DCT_h_scaled_size = 9;
122 cinfo->min_DCT_v_scaled_size = 9;
123 } else if (cinfo->scale_num * 5 >= cinfo->scale_denom * 4) {
124 /* Provide 4/5 scaling */
125 cinfo->jpeg_width = (JDIMENSION)
126 jdiv_round_up((long) cinfo->image_width * 4, 5L);
127 cinfo->jpeg_height = (JDIMENSION)
128 jdiv_round_up((long) cinfo->image_height * 4, 5L);
129 cinfo->min_DCT_h_scaled_size = 10;
130 cinfo->min_DCT_v_scaled_size = 10;
131 } else if (cinfo->scale_num * 11 >= cinfo->scale_denom * 8) {
132 /* Provide 8/11 scaling */
133 cinfo->jpeg_width = (JDIMENSION)
134 jdiv_round_up((long) cinfo->image_width * 8, 11L);
135 cinfo->jpeg_height = (JDIMENSION)
136 jdiv_round_up((long) cinfo->image_height * 8, 11L);
137 cinfo->min_DCT_h_scaled_size = 11;
138 cinfo->min_DCT_v_scaled_size = 11;
139 } else if (cinfo->scale_num * 3 >= cinfo->scale_denom * 2) {
140 /* Provide 2/3 scaling */
141 cinfo->jpeg_width = (JDIMENSION)
142 jdiv_round_up((long) cinfo->image_width * 2, 3L);
143 cinfo->jpeg_height = (JDIMENSION)
144 jdiv_round_up((long) cinfo->image_height * 2, 3L);
145 cinfo->min_DCT_h_scaled_size = 12;
146 cinfo->min_DCT_v_scaled_size = 12;
147 } else if (cinfo->scale_num * 13 >= cinfo->scale_denom * 8) {
148 /* Provide 8/13 scaling */
149 cinfo->jpeg_width = (JDIMENSION)
150 jdiv_round_up((long) cinfo->image_width * 8, 13L);
151 cinfo->jpeg_height = (JDIMENSION)
152 jdiv_round_up((long) cinfo->image_height * 8, 13L);
153 cinfo->min_DCT_h_scaled_size = 13;
154 cinfo->min_DCT_v_scaled_size = 13;
155 } else if (cinfo->scale_num * 7 >= cinfo->scale_denom * 4) {
156 /* Provide 4/7 scaling */
157 cinfo->jpeg_width = (JDIMENSION)
158 jdiv_round_up((long) cinfo->image_width * 4, 7L);
159 cinfo->jpeg_height = (JDIMENSION)
160 jdiv_round_up((long) cinfo->image_height * 4, 7L);
161 cinfo->min_DCT_h_scaled_size = 14;
162 cinfo->min_DCT_v_scaled_size = 14;
163 } else if (cinfo->scale_num * 15 >= cinfo->scale_denom * 8) {
164 /* Provide 8/15 scaling */
165 cinfo->jpeg_width = (JDIMENSION)
166 jdiv_round_up((long) cinfo->image_width * 8, 15L);
167 cinfo->jpeg_height = (JDIMENSION)
168 jdiv_round_up((long) cinfo->image_height * 8, 15L);
169 cinfo->min_DCT_h_scaled_size = 15;
170 cinfo->min_DCT_v_scaled_size = 15;
171 } else {
172 /* Provide 1/2 scaling */
173 cinfo->jpeg_width = (JDIMENSION)
174 jdiv_round_up((long) cinfo->image_width, 2L);
175 cinfo->jpeg_height = (JDIMENSION)
176 jdiv_round_up((long) cinfo->image_height, 2L);
177 cinfo->min_DCT_h_scaled_size = 16;
178 cinfo->min_DCT_v_scaled_size = 16;
179 }
180
181#else /* !DCT_SCALING_SUPPORTED */
182
183 /* Hardwire it to "no scaling" */
184 cinfo->jpeg_width = cinfo->image_width;
185 cinfo->jpeg_height = cinfo->image_height;
186 cinfo->min_DCT_h_scaled_size = DCTSIZE;
187 cinfo->min_DCT_v_scaled_size = DCTSIZE;
188
189#endif /* DCT_SCALING_SUPPORTED */
190
191 cinfo->block_size = DCTSIZE;
192 cinfo->natural_order = jpeg_natural_order;
193 cinfo->lim_Se = DCTSIZE2-1;
194}
195
196
197LOCAL(void)
198jpeg_calc_trans_dimensions (j_compress_ptr cinfo)
199{
200 if (cinfo->min_DCT_h_scaled_size < 1 || cinfo->min_DCT_h_scaled_size > 16
201 || cinfo->min_DCT_h_scaled_size != cinfo->min_DCT_v_scaled_size)
202 ERREXIT2(cinfo, JERR_BAD_DCTSIZE,
203 cinfo->min_DCT_h_scaled_size, cinfo->min_DCT_v_scaled_size);
204
205 cinfo->block_size = cinfo->min_DCT_h_scaled_size;
206
207 switch (cinfo->block_size) {
208 case 2: cinfo->natural_order = jpeg_natural_order2; break;
209 case 3: cinfo->natural_order = jpeg_natural_order3; break;
210 case 4: cinfo->natural_order = jpeg_natural_order4; break;
211 case 5: cinfo->natural_order = jpeg_natural_order5; break;
212 case 6: cinfo->natural_order = jpeg_natural_order6; break;
213 case 7: cinfo->natural_order = jpeg_natural_order7; break;
214 default: cinfo->natural_order = jpeg_natural_order; break;
215 }
216
217 cinfo->lim_Se = cinfo->block_size < DCTSIZE ?
218 cinfo->block_size * cinfo->block_size - 1 : DCTSIZE2-1;
219}
220
221
222LOCAL(void)
223initial_setup (j_compress_ptr cinfo, boolean transcode_only)
224/* Do computations that are needed before master selection phase */
225{
226 int ci, ssize;
227 jpeg_component_info *compptr;
228 long samplesperrow;
229 JDIMENSION jd_samplesperrow;
230
231 if (transcode_only)
232 jpeg_calc_trans_dimensions(cinfo);
233 else
234 jpeg_calc_jpeg_dimensions(cinfo);
235
236 /* Sanity check on image dimensions */
237 if (cinfo->jpeg_height <= 0 || cinfo->jpeg_width <= 0 ||
238 cinfo->num_components <= 0 || cinfo->input_components <= 0)
239 ERREXIT(cinfo, JERR_EMPTY_IMAGE);
240
241 /* Make sure image isn't bigger than I can handle */
242 if ((long) cinfo->jpeg_height > (long) JPEG_MAX_DIMENSION ||
243 (long) cinfo->jpeg_width > (long) JPEG_MAX_DIMENSION)
244 ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) JPEG_MAX_DIMENSION);
245
246 /* Width of an input scanline must be representable as JDIMENSION. */
247 samplesperrow = (long) cinfo->image_width * (long) cinfo->input_components;
248 jd_samplesperrow = (JDIMENSION) samplesperrow;
249 if ((long) jd_samplesperrow != samplesperrow)
250 ERREXIT(cinfo, JERR_WIDTH_OVERFLOW);
251
252 /* For now, precision must match compiled-in value... */
253 if (cinfo->data_precision != BITS_IN_JSAMPLE)
254 ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision);
255
256 /* Check that number of components won't exceed internal array sizes */
257 if (cinfo->num_components > MAX_COMPONENTS)
258 ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components,
259 MAX_COMPONENTS);
260
261 /* Compute maximum sampling factors; check factor validity */
262 cinfo->max_h_samp_factor = 1;
263 cinfo->max_v_samp_factor = 1;
264 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
265 ci++, compptr++) {
266 if (compptr->h_samp_factor<=0 || compptr->h_samp_factor>MAX_SAMP_FACTOR ||
267 compptr->v_samp_factor<=0 || compptr->v_samp_factor>MAX_SAMP_FACTOR)
268 ERREXIT(cinfo, JERR_BAD_SAMPLING);
269 cinfo->max_h_samp_factor = MAX(cinfo->max_h_samp_factor,
270 compptr->h_samp_factor);
271 cinfo->max_v_samp_factor = MAX(cinfo->max_v_samp_factor,
272 compptr->v_samp_factor);
273 }
274
275 /* Compute dimensions of components */
276 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
277 ci++, compptr++) {
278 /* Fill in the correct component_index value; don't rely on application */
279 compptr->component_index = ci;
280 /* In selecting the actual DCT scaling for each component, we try to
281 * scale down the chroma components via DCT scaling rather than downsampling.
282 * This saves time if the downsampler gets to use 1:1 scaling.
283 * Note this code adapts subsampling ratios which are powers of 2.
284 */
285 ssize = 1;
286#ifdef DCT_SCALING_SUPPORTED
287 while (cinfo->min_DCT_h_scaled_size * ssize <=
288 (cinfo->do_fancy_downsampling ? DCTSIZE : DCTSIZE / 2) &&
289 (cinfo->max_h_samp_factor % (compptr->h_samp_factor * ssize * 2)) == 0) {
290 ssize = ssize * 2;
291 }
292#endif
293 compptr->DCT_h_scaled_size = cinfo->min_DCT_h_scaled_size * ssize;
294 ssize = 1;
295#ifdef DCT_SCALING_SUPPORTED
296 while (cinfo->min_DCT_v_scaled_size * ssize <=
297 (cinfo->do_fancy_downsampling ? DCTSIZE : DCTSIZE / 2) &&
298 (cinfo->max_v_samp_factor % (compptr->v_samp_factor * ssize * 2)) == 0) {
299 ssize = ssize * 2;
300 }
301#endif
302 compptr->DCT_v_scaled_size = cinfo->min_DCT_v_scaled_size * ssize;
303
304 /* We don't support DCT ratios larger than 2. */
305 if (compptr->DCT_h_scaled_size > compptr->DCT_v_scaled_size * 2)
306 compptr->DCT_h_scaled_size = compptr->DCT_v_scaled_size * 2;
307 else if (compptr->DCT_v_scaled_size > compptr->DCT_h_scaled_size * 2)
308 compptr->DCT_v_scaled_size = compptr->DCT_h_scaled_size * 2;
309
310 /* Size in DCT blocks */
311 compptr->width_in_blocks = (JDIMENSION)
312 jdiv_round_up((long) cinfo->jpeg_width * (long) compptr->h_samp_factor,
313 (long) (cinfo->max_h_samp_factor * cinfo->block_size));
314 compptr->height_in_blocks = (JDIMENSION)
315 jdiv_round_up((long) cinfo->jpeg_height * (long) compptr->v_samp_factor,
316 (long) (cinfo->max_v_samp_factor * cinfo->block_size));
317 /* Size in samples */
318 compptr->downsampled_width = (JDIMENSION)
319 jdiv_round_up((long) cinfo->jpeg_width *
320 (long) (compptr->h_samp_factor * compptr->DCT_h_scaled_size),
321 (long) (cinfo->max_h_samp_factor * cinfo->block_size));
322 compptr->downsampled_height = (JDIMENSION)
323 jdiv_round_up((long) cinfo->jpeg_height *
324 (long) (compptr->v_samp_factor * compptr->DCT_v_scaled_size),
325 (long) (cinfo->max_v_samp_factor * cinfo->block_size));
326 /* Mark component needed (this flag isn't actually used for compression) */
327 compptr->component_needed = TRUE;
328 }
329
330 /* Compute number of fully interleaved MCU rows (number of times that
331 * main controller will call coefficient controller).
332 */
333 cinfo->total_iMCU_rows = (JDIMENSION)
334 jdiv_round_up((long) cinfo->jpeg_height,
335 (long) (cinfo->max_v_samp_factor * cinfo->block_size));
336}
337
338
339#ifdef C_MULTISCAN_FILES_SUPPORTED
340
341LOCAL(void)
342validate_script (j_compress_ptr cinfo)
343/* Verify that the scan script in cinfo->scan_info[] is valid; also
344 * determine whether it uses progressive JPEG, and set cinfo->progressive_mode.
345 */
346{
347 const jpeg_scan_info * scanptr;
348 int scanno, ncomps, ci, coefi, thisi;
349 int Ss, Se, Ah, Al;
350 boolean component_sent[MAX_COMPONENTS];
351#ifdef C_PROGRESSIVE_SUPPORTED
352 int * last_bitpos_ptr;
353 int last_bitpos[MAX_COMPONENTS][DCTSIZE2];
354 /* -1 until that coefficient has been seen; then last Al for it */
355#endif
356
357 if (cinfo->num_scans <= 0)
358 ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, 0);
359
360 /* For sequential JPEG, all scans must have Ss=0, Se=DCTSIZE2-1;
361 * for progressive JPEG, no scan can have this.
362 */
363 scanptr = cinfo->scan_info;
364 if (scanptr->Ss != 0 || scanptr->Se != DCTSIZE2-1) {
365#ifdef C_PROGRESSIVE_SUPPORTED
366 cinfo->progressive_mode = TRUE;
367 last_bitpos_ptr = & last_bitpos[0][0];
368 for (ci = 0; ci < cinfo->num_components; ci++)
369 for (coefi = 0; coefi < DCTSIZE2; coefi++)
370 *last_bitpos_ptr++ = -1;
371#else
372 ERREXIT(cinfo, JERR_NOT_COMPILED);
373#endif
374 } else {
375 cinfo->progressive_mode = FALSE;
376 for (ci = 0; ci < cinfo->num_components; ci++)
377 component_sent[ci] = FALSE;
378 }
379
380 for (scanno = 1; scanno <= cinfo->num_scans; scanptr++, scanno++) {
381 /* Validate component indexes */
382 ncomps = scanptr->comps_in_scan;
383 if (ncomps <= 0 || ncomps > MAX_COMPS_IN_SCAN)
384 ERREXIT2(cinfo, JERR_COMPONENT_COUNT, ncomps, MAX_COMPS_IN_SCAN);
385 for (ci = 0; ci < ncomps; ci++) {
386 thisi = scanptr->component_index[ci];
387 if (thisi < 0 || thisi >= cinfo->num_components)
388 ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, scanno);
389 /* Components must appear in SOF order within each scan */
390 if (ci > 0 && thisi <= scanptr->component_index[ci-1])
391 ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, scanno);
392 }
393 /* Validate progression parameters */
394 Ss = scanptr->Ss;
395 Se = scanptr->Se;
396 Ah = scanptr->Ah;
397 Al = scanptr->Al;
398 if (cinfo->progressive_mode) {
399#ifdef C_PROGRESSIVE_SUPPORTED
400 /* The JPEG spec simply gives the ranges 0..13 for Ah and Al, but that
401 * seems wrong: the upper bound ought to depend on data precision.
402 * Perhaps they really meant 0..N+1 for N-bit precision.
403 * Here we allow 0..10 for 8-bit data; Al larger than 10 results in
404 * out-of-range reconstructed DC values during the first DC scan,
405 * which might cause problems for some decoders.
406 */
407#if BITS_IN_JSAMPLE == 8
408#define MAX_AH_AL 10
409#else
410#define MAX_AH_AL 13
411#endif
412 if (Ss < 0 || Ss >= DCTSIZE2 || Se < Ss || Se >= DCTSIZE2 ||
413 Ah < 0 || Ah > MAX_AH_AL || Al < 0 || Al > MAX_AH_AL)
414 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
415 if (Ss == 0) {
416 if (Se != 0) /* DC and AC together not OK */
417 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
418 } else {
419 if (ncomps != 1) /* AC scans must be for only one component */
420 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
421 }
422 for (ci = 0; ci < ncomps; ci++) {
423 last_bitpos_ptr = & last_bitpos[scanptr->component_index[ci]][0];
424 if (Ss != 0 && last_bitpos_ptr[0] < 0) /* AC without prior DC scan */
425 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
426 for (coefi = Ss; coefi <= Se; coefi++) {
427 if (last_bitpos_ptr[coefi] < 0) {
428 /* first scan of this coefficient */
429 if (Ah != 0)
430 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
431 } else {
432 /* not first scan */
433 if (Ah != last_bitpos_ptr[coefi] || Al != Ah-1)
434 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
435 }
436 last_bitpos_ptr[coefi] = Al;
437 }
438 }
439#endif
440 } else {
441 /* For sequential JPEG, all progression parameters must be these: */
442 if (Ss != 0 || Se != DCTSIZE2-1 || Ah != 0 || Al != 0)
443 ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
444 /* Make sure components are not sent twice */
445 for (ci = 0; ci < ncomps; ci++) {
446 thisi = scanptr->component_index[ci];
447 if (component_sent[thisi])
448 ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, scanno);
449 component_sent[thisi] = TRUE;
450 }
451 }
452 }
453
454 /* Now verify that everything got sent. */
455 if (cinfo->progressive_mode) {
456#ifdef C_PROGRESSIVE_SUPPORTED
457 /* For progressive mode, we only check that at least some DC data
458 * got sent for each component; the spec does not require that all bits
459 * of all coefficients be transmitted. Would it be wiser to enforce
460 * transmission of all coefficient bits??
461 */
462 for (ci = 0; ci < cinfo->num_components; ci++) {
463 if (last_bitpos[ci][0] < 0)
464 ERREXIT(cinfo, JERR_MISSING_DATA);
465 }
466#endif
467 } else {
468 for (ci = 0; ci < cinfo->num_components; ci++) {
469 if (! component_sent[ci])
470 ERREXIT(cinfo, JERR_MISSING_DATA);
471 }
472 }
473}
474
475
476LOCAL(void)
477reduce_script (j_compress_ptr cinfo)
478/* Adapt scan script for use with reduced block size;
479 * assume that script has been validated before.
480 */
481{
482 jpeg_scan_info * scanptr;
483 int idxout, idxin;
484
485 /* Circumvent const declaration for this function */
486 scanptr = (jpeg_scan_info *) cinfo->scan_info;
487 idxout = 0;
488
489 for (idxin = 0; idxin < cinfo->num_scans; idxin++) {
490 /* After skipping, idxout becomes smaller than idxin */
491 if (idxin != idxout)
492 /* Copy rest of data;
493 * note we stay in given chunk of allocated memory.
494 */
495 scanptr[idxout] = scanptr[idxin];
496 if (scanptr[idxout].Ss > cinfo->lim_Se)
497 /* Entire scan out of range - skip this entry */
498 continue;
499 if (scanptr[idxout].Se > cinfo->lim_Se)
500 /* Limit scan to end of block */
501 scanptr[idxout].Se = cinfo->lim_Se;
502 idxout++;
503 }
504
505 cinfo->num_scans = idxout;
506}
507
508#endif /* C_MULTISCAN_FILES_SUPPORTED */
509
510
511LOCAL(void)
512select_scan_parameters (j_compress_ptr cinfo)
513/* Set up the scan parameters for the current scan */
514{
515 int ci;
516
517#ifdef C_MULTISCAN_FILES_SUPPORTED
518 if (cinfo->scan_info != NULL) {
519 /* Prepare for current scan --- the script is already validated */
520 my_master_ptr master = (my_master_ptr) cinfo->master;
521 const jpeg_scan_info * scanptr = cinfo->scan_info + master->scan_number;
522
523 cinfo->comps_in_scan = scanptr->comps_in_scan;
524 for (ci = 0; ci < scanptr->comps_in_scan; ci++) {
525 cinfo->cur_comp_info[ci] =
526 &cinfo->comp_info[scanptr->component_index[ci]];
527 }
528 if (cinfo->progressive_mode) {
529 cinfo->Ss = scanptr->Ss;
530 cinfo->Se = scanptr->Se;
531 cinfo->Ah = scanptr->Ah;
532 cinfo->Al = scanptr->Al;
533 return;
534 }
535 }
536 else
537#endif
538 {
539 /* Prepare for single sequential-JPEG scan containing all components */
540 if (cinfo->num_components > MAX_COMPS_IN_SCAN)
541 ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components,
542 MAX_COMPS_IN_SCAN);
543 cinfo->comps_in_scan = cinfo->num_components;
544 for (ci = 0; ci < cinfo->num_components; ci++) {
545 cinfo->cur_comp_info[ci] = &cinfo->comp_info[ci];
546 }
547 }
548 cinfo->Ss = 0;
549 cinfo->Se = cinfo->block_size * cinfo->block_size - 1;
550 cinfo->Ah = 0;
551 cinfo->Al = 0;
552}
553
554
555LOCAL(void)
556per_scan_setup (j_compress_ptr cinfo)
557/* Do computations that are needed before processing a JPEG scan */
558/* cinfo->comps_in_scan and cinfo->cur_comp_info[] are already set */
559{
560 int ci, mcublks, tmp;
561 jpeg_component_info *compptr;
562
563 if (cinfo->comps_in_scan == 1) {
564
565 /* Noninterleaved (single-component) scan */
566 compptr = cinfo->cur_comp_info[0];
567
568 /* Overall image size in MCUs */
569 cinfo->MCUs_per_row = compptr->width_in_blocks;
570 cinfo->MCU_rows_in_scan = compptr->height_in_blocks;
571
572 /* For noninterleaved scan, always one block per MCU */
573 compptr->MCU_width = 1;
574 compptr->MCU_height = 1;
575 compptr->MCU_blocks = 1;
576 compptr->MCU_sample_width = compptr->DCT_h_scaled_size;
577 compptr->last_col_width = 1;
578 /* For noninterleaved scans, it is convenient to define last_row_height
579 * as the number of block rows present in the last iMCU row.
580 */
581 tmp = (int) (compptr->height_in_blocks % compptr->v_samp_factor);
582 if (tmp == 0) tmp = compptr->v_samp_factor;
583 compptr->last_row_height = tmp;
584
585 /* Prepare array describing MCU composition */
586 cinfo->blocks_in_MCU = 1;
587 cinfo->MCU_membership[0] = 0;
588
589 } else {
590
591 /* Interleaved (multi-component) scan */
592 if (cinfo->comps_in_scan <= 0 || cinfo->comps_in_scan > MAX_COMPS_IN_SCAN)
593 ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->comps_in_scan,
594 MAX_COMPS_IN_SCAN);
595
596 /* Overall image size in MCUs */
597 cinfo->MCUs_per_row = (JDIMENSION)
598 jdiv_round_up((long) cinfo->jpeg_width,
599 (long) (cinfo->max_h_samp_factor * cinfo->block_size));
600 cinfo->MCU_rows_in_scan = (JDIMENSION)
601 jdiv_round_up((long) cinfo->jpeg_height,
602 (long) (cinfo->max_v_samp_factor * cinfo->block_size));
603
604 cinfo->blocks_in_MCU = 0;
605
606 for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
607 compptr = cinfo->cur_comp_info[ci];
608 /* Sampling factors give # of blocks of component in each MCU */
609 compptr->MCU_width = compptr->h_samp_factor;
610 compptr->MCU_height = compptr->v_samp_factor;
611 compptr->MCU_blocks = compptr->MCU_width * compptr->MCU_height;
612 compptr->MCU_sample_width = compptr->MCU_width * compptr->DCT_h_scaled_size;
613 /* Figure number of non-dummy blocks in last MCU column & row */
614 tmp = (int) (compptr->width_in_blocks % compptr->MCU_width);
615 if (tmp == 0) tmp = compptr->MCU_width;
616 compptr->last_col_width = tmp;
617 tmp = (int) (compptr->height_in_blocks % compptr->MCU_height);
618 if (tmp == 0) tmp = compptr->MCU_height;
619 compptr->last_row_height = tmp;
620 /* Prepare array describing MCU composition */
621 mcublks = compptr->MCU_blocks;
622 if (cinfo->blocks_in_MCU + mcublks > C_MAX_BLOCKS_IN_MCU)
623 ERREXIT(cinfo, JERR_BAD_MCU_SIZE);
624 while (mcublks-- > 0) {
625 cinfo->MCU_membership[cinfo->blocks_in_MCU++] = ci;
626 }
627 }
628
629 }
630
631 /* Convert restart specified in rows to actual MCU count. */
632 /* Note that count must fit in 16 bits, so we provide limiting. */
633 if (cinfo->restart_in_rows > 0) {
634 long nominal = (long) cinfo->restart_in_rows * (long) cinfo->MCUs_per_row;
635 cinfo->restart_interval = (unsigned int) MIN(nominal, 65535L);
636 }
637}
638
639
640/*
641 * Per-pass setup.
642 * This is called at the beginning of each pass. We determine which modules
643 * will be active during this pass and give them appropriate start_pass calls.
644 * We also set is_last_pass to indicate whether any more passes will be
645 * required.
646 */
647
648METHODDEF(void)
649prepare_for_pass (j_compress_ptr cinfo)
650{
651 my_master_ptr master = (my_master_ptr) cinfo->master;
652
653 switch (master->pass_type) {
654 case main_pass:
655 /* Initial pass: will collect input data, and do either Huffman
656 * optimization or data output for the first scan.
657 */
658 select_scan_parameters(cinfo);
659 per_scan_setup(cinfo);
660 if (! cinfo->raw_data_in) {
661 (*cinfo->cconvert->start_pass) (cinfo);
662 (*cinfo->downsample->start_pass) (cinfo);
663 (*cinfo->prep->start_pass) (cinfo, JBUF_PASS_THRU);
664 }
665 (*cinfo->fdct->start_pass) (cinfo);
666 (*cinfo->entropy->start_pass) (cinfo, cinfo->optimize_coding);
667 (*cinfo->coef->start_pass) (cinfo,
668 (master->total_passes > 1 ?
669 JBUF_SAVE_AND_PASS : JBUF_PASS_THRU));
670 (*cinfo->main->start_pass) (cinfo, JBUF_PASS_THRU);
671 if (cinfo->optimize_coding) {
672 /* No immediate data output; postpone writing frame/scan headers */
673 master->pub.call_pass_startup = FALSE;
674 } else {
675 /* Will write frame/scan headers at first jpeg_write_scanlines call */
676 master->pub.call_pass_startup = TRUE;
677 }
678 break;
679#ifdef ENTROPY_OPT_SUPPORTED
680 case huff_opt_pass:
681 /* Do Huffman optimization for a scan after the first one. */
682 select_scan_parameters(cinfo);
683 per_scan_setup(cinfo);
684 if (cinfo->Ss != 0 || cinfo->Ah == 0) {
685 (*cinfo->entropy->start_pass) (cinfo, TRUE);
686 (*cinfo->coef->start_pass) (cinfo, JBUF_CRANK_DEST);
687 master->pub.call_pass_startup = FALSE;
688 break;
689 }
690 /* Special case: Huffman DC refinement scans need no Huffman table
691 * and therefore we can skip the optimization pass for them.
692 */
693 master->pass_type = output_pass;
694 master->pass_number++;
695 /*FALLTHROUGH*/
696#endif
697 case output_pass:
698 /* Do a data-output pass. */
699 /* We need not repeat per-scan setup if prior optimization pass did it. */
700 if (! cinfo->optimize_coding) {
701 select_scan_parameters(cinfo);
702 per_scan_setup(cinfo);
703 }
704 (*cinfo->entropy->start_pass) (cinfo, FALSE);
705 (*cinfo->coef->start_pass) (cinfo, JBUF_CRANK_DEST);
706 /* We emit frame/scan headers now */
707 if (master->scan_number == 0)
708 (*cinfo->marker->write_frame_header) (cinfo);
709 (*cinfo->marker->write_scan_header) (cinfo);
710 master->pub.call_pass_startup = FALSE;
711 break;
712 default:
713 ERREXIT(cinfo, JERR_NOT_COMPILED);
714 }
715
716 master->pub.is_last_pass = (master->pass_number == master->total_passes-1);
717
718 /* Set up progress monitor's pass info if present */
719 if (cinfo->progress != NULL) {
720 cinfo->progress->completed_passes = master->pass_number;
721 cinfo->progress->total_passes = master->total_passes;
722 }
723}
724
725
726/*
727 * Special start-of-pass hook.
728 * This is called by jpeg_write_scanlines if call_pass_startup is TRUE.
729 * In single-pass processing, we need this hook because we don't want to
730 * write frame/scan headers during jpeg_start_compress; we want to let the
731 * application write COM markers etc. between jpeg_start_compress and the
732 * jpeg_write_scanlines loop.
733 * In multi-pass processing, this routine is not used.
734 */
735
736METHODDEF(void)
737pass_startup (j_compress_ptr cinfo)
738{
739 cinfo->master->call_pass_startup = FALSE; /* reset flag so call only once */
740
741 (*cinfo->marker->write_frame_header) (cinfo);
742 (*cinfo->marker->write_scan_header) (cinfo);
743}
744
745
746/*
747 * Finish up at end of pass.
748 */
749
750METHODDEF(void)
751finish_pass_master (j_compress_ptr cinfo)
752{
753 my_master_ptr master = (my_master_ptr) cinfo->master;
754
755 /* The entropy coder always needs an end-of-pass call,
756 * either to analyze statistics or to flush its output buffer.
757 */
758 (*cinfo->entropy->finish_pass) (cinfo);
759
760 /* Update state for next pass */
761 switch (master->pass_type) {
762 case main_pass:
763 /* next pass is either output of scan 0 (after optimization)
764 * or output of scan 1 (if no optimization).
765 */
766 master->pass_type = output_pass;
767 if (! cinfo->optimize_coding)
768 master->scan_number++;
769 break;
770 case huff_opt_pass:
771 /* next pass is always output of current scan */
772 master->pass_type = output_pass;
773 break;
774 case output_pass:
775 /* next pass is either optimization or output of next scan */
776 if (cinfo->optimize_coding)
777 master->pass_type = huff_opt_pass;
778 master->scan_number++;
779 break;
780 }
781
782 master->pass_number++;
783}
784
785
786/*
787 * Initialize master compression control.
788 */
789
790GLOBAL(void)
791jinit_c_master_control (j_compress_ptr cinfo, boolean transcode_only)
792{
793 my_master_ptr master;
794
795 master = (my_master_ptr)
796 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
797 SIZEOF(my_comp_master));
798 cinfo->master = (struct jpeg_comp_master *) master;
799 master->pub.prepare_for_pass = prepare_for_pass;
800 master->pub.pass_startup = pass_startup;
801 master->pub.finish_pass = finish_pass_master;
802 master->pub.is_last_pass = FALSE;
803
804 /* Validate parameters, determine derived values */
805 initial_setup(cinfo, transcode_only);
806
807 if (cinfo->scan_info != NULL) {
808#ifdef C_MULTISCAN_FILES_SUPPORTED
809 validate_script(cinfo);
810 if (cinfo->block_size < DCTSIZE)
811 reduce_script(cinfo);
812#else
813 ERREXIT(cinfo, JERR_NOT_COMPILED);
814#endif
815 } else {
816 cinfo->progressive_mode = FALSE;
817 cinfo->num_scans = 1;
818 }
819
820 if ((cinfo->progressive_mode || cinfo->block_size < DCTSIZE) &&
821 !cinfo->arith_code) /* TEMPORARY HACK ??? */
822 /* assume default tables no good for progressive or downscale mode */
823 cinfo->optimize_coding = TRUE;
824
825 /* Initialize my private state */
826 if (transcode_only) {
827 /* no main pass in transcoding */
828 if (cinfo->optimize_coding)
829 master->pass_type = huff_opt_pass;
830 else
831 master->pass_type = output_pass;
832 } else {
833 /* for normal compression, first pass is always this type: */
834 master->pass_type = main_pass;
835 }
836 master->scan_number = 0;
837 master->pass_number = 0;
838 if (cinfo->optimize_coding)
839 master->total_passes = cinfo->num_scans * 2;
840 else
841 master->total_passes = cinfo->num_scans;
842}
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