1 : /*
2 : * jdmaster.c
3 : *
4 : * Copyright (C) 1991-1997, Thomas G. Lane.
5 : * Copyright (C) 2009-2011, D. R. Commander.
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 decompressor.
10 : * These routines are concerned with selecting the modules to be executed
11 : * and with determining the number of passes and the work to be done in each
12 : * pass.
13 : */
14 :
15 : #define JPEG_INTERNALS
16 : #include "jinclude.h"
17 : #include "jpeglib.h"
18 : #include "jpegcomp.h"
19 :
20 :
21 : /* Private state */
22 :
23 : typedef struct {
24 : struct jpeg_decomp_master pub; /* public fields */
25 :
26 : int pass_number; /* # of passes completed */
27 :
28 : boolean using_merged_upsample; /* TRUE if using merged upsample/cconvert */
29 :
30 : /* Saved references to initialized quantizer modules,
31 : * in case we need to switch modes.
32 : */
33 : struct jpeg_color_quantizer * quantizer_1pass;
34 : struct jpeg_color_quantizer * quantizer_2pass;
35 : } my_decomp_master;
36 :
37 : typedef my_decomp_master * my_master_ptr;
38 :
39 :
40 : /*
41 : * Determine whether merged upsample/color conversion should be used.
42 : * CRUCIAL: this must match the actual capabilities of jdmerge.c!
43 : */
44 :
45 : LOCAL(boolean)
46 15 : use_merged_upsample (j_decompress_ptr cinfo)
47 : {
48 : #ifdef UPSAMPLE_MERGING_SUPPORTED
49 : /* Merging is the equivalent of plain box-filter upsampling */
50 15 : if (cinfo->do_fancy_upsampling || cinfo->CCIR601_sampling)
51 15 : return FALSE;
52 : /* jdmerge.c only supports YCC=>RGB color conversion */
53 0 : if (cinfo->jpeg_color_space != JCS_YCbCr || cinfo->num_components != 3 ||
54 0 : (cinfo->out_color_space != JCS_RGB &&
55 0 : cinfo->out_color_space != JCS_EXT_RGB &&
56 0 : cinfo->out_color_space != JCS_EXT_RGBX &&
57 0 : cinfo->out_color_space != JCS_EXT_BGR &&
58 0 : cinfo->out_color_space != JCS_EXT_BGRX &&
59 0 : cinfo->out_color_space != JCS_EXT_XBGR &&
60 0 : cinfo->out_color_space != JCS_EXT_XRGB &&
61 0 : cinfo->out_color_space != JCS_EXT_RGBA &&
62 0 : cinfo->out_color_space != JCS_EXT_BGRA &&
63 0 : cinfo->out_color_space != JCS_EXT_ABGR &&
64 0 : cinfo->out_color_space != JCS_EXT_ARGB) ||
65 0 : cinfo->out_color_components != rgb_pixelsize[cinfo->out_color_space])
66 0 : return FALSE;
67 : /* and it only handles 2h1v or 2h2v sampling ratios */
68 0 : if (cinfo->comp_info[0].h_samp_factor != 2 ||
69 0 : cinfo->comp_info[1].h_samp_factor != 1 ||
70 0 : cinfo->comp_info[2].h_samp_factor != 1 ||
71 0 : cinfo->comp_info[0].v_samp_factor > 2 ||
72 0 : cinfo->comp_info[1].v_samp_factor != 1 ||
73 0 : cinfo->comp_info[2].v_samp_factor != 1)
74 0 : return FALSE;
75 : /* furthermore, it doesn't work if we've scaled the IDCTs differently */
76 0 : if (cinfo->comp_info[0]._DCT_scaled_size != cinfo->_min_DCT_scaled_size ||
77 0 : cinfo->comp_info[1]._DCT_scaled_size != cinfo->_min_DCT_scaled_size ||
78 0 : cinfo->comp_info[2]._DCT_scaled_size != cinfo->_min_DCT_scaled_size)
79 0 : return FALSE;
80 : /* ??? also need to test for upsample-time rescaling, when & if supported */
81 0 : return TRUE; /* by golly, it'll work... */
82 : #else
83 : return FALSE;
84 : #endif
85 : }
86 :
87 :
88 : /*
89 : * Compute output image dimensions and related values.
90 : * NOTE: this is exported for possible use by application.
91 : * Hence it mustn't do anything that can't be done twice.
92 : * Also note that it may be called before the master module is initialized!
93 : */
94 :
95 : GLOBAL(void)
96 10 : jpeg_calc_output_dimensions (j_decompress_ptr cinfo)
97 : /* Do computations that are needed before master selection phase */
98 : {
99 : #ifdef IDCT_SCALING_SUPPORTED
100 : int ci;
101 : jpeg_component_info *compptr;
102 : #endif
103 :
104 : /* Prevent application from calling me at wrong times */
105 10 : if (cinfo->global_state != DSTATE_READY)
106 0 : ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
107 :
108 : #ifdef IDCT_SCALING_SUPPORTED
109 :
110 : /* Compute actual output image dimensions and DCT scaling choices. */
111 10 : if (cinfo->scale_num * 8 <= cinfo->scale_denom) {
112 : /* Provide 1/8 scaling */
113 0 : cinfo->output_width = (JDIMENSION)
114 0 : jdiv_round_up((long) cinfo->image_width, 8L);
115 0 : cinfo->output_height = (JDIMENSION)
116 0 : jdiv_round_up((long) cinfo->image_height, 8L);
117 : #if JPEG_LIB_VERSION >= 70
118 : cinfo->min_DCT_h_scaled_size = cinfo->min_DCT_v_scaled_size = 1;
119 : #else
120 0 : cinfo->min_DCT_scaled_size = 1;
121 : #endif
122 10 : } else if (cinfo->scale_num * 4 <= cinfo->scale_denom) {
123 : /* Provide 1/4 scaling */
124 0 : cinfo->output_width = (JDIMENSION)
125 0 : jdiv_round_up((long) cinfo->image_width, 4L);
126 0 : cinfo->output_height = (JDIMENSION)
127 0 : jdiv_round_up((long) cinfo->image_height, 4L);
128 : #if JPEG_LIB_VERSION >= 70
129 : cinfo->min_DCT_h_scaled_size = cinfo->min_DCT_v_scaled_size = 2;
130 : #else
131 0 : cinfo->min_DCT_scaled_size = 2;
132 : #endif
133 10 : } else if (cinfo->scale_num * 2 <= cinfo->scale_denom) {
134 : /* Provide 1/2 scaling */
135 0 : cinfo->output_width = (JDIMENSION)
136 0 : jdiv_round_up((long) cinfo->image_width, 2L);
137 0 : cinfo->output_height = (JDIMENSION)
138 0 : jdiv_round_up((long) cinfo->image_height, 2L);
139 : #if JPEG_LIB_VERSION >= 70
140 : cinfo->min_DCT_h_scaled_size = cinfo->min_DCT_v_scaled_size = 4;
141 : #else
142 0 : cinfo->min_DCT_scaled_size = 4;
143 : #endif
144 : } else {
145 : /* Provide 1/1 scaling */
146 10 : cinfo->output_width = cinfo->image_width;
147 10 : cinfo->output_height = cinfo->image_height;
148 : #if JPEG_LIB_VERSION >= 70
149 : cinfo->min_DCT_h_scaled_size = cinfo->min_DCT_v_scaled_size = DCTSIZE;
150 : #else
151 10 : cinfo->min_DCT_scaled_size = DCTSIZE;
152 : #endif
153 : }
154 : /* In selecting the actual DCT scaling for each component, we try to
155 : * scale up the chroma components via IDCT scaling rather than upsampling.
156 : * This saves time if the upsampler gets to use 1:1 scaling.
157 : * Note this code assumes that the supported DCT scalings are powers of 2.
158 : */
159 50 : for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
160 30 : ci++, compptr++) {
161 30 : int ssize = cinfo->_min_DCT_scaled_size;
162 60 : while (ssize < DCTSIZE &&
163 0 : (compptr->h_samp_factor * ssize * 2 <=
164 0 : cinfo->max_h_samp_factor * cinfo->_min_DCT_scaled_size) &&
165 0 : (compptr->v_samp_factor * ssize * 2 <=
166 0 : cinfo->max_v_samp_factor * cinfo->_min_DCT_scaled_size)) {
167 0 : ssize = ssize * 2;
168 : }
169 : #if JPEG_LIB_VERSION >= 70
170 : compptr->DCT_h_scaled_size = compptr->DCT_v_scaled_size = ssize;
171 : #else
172 30 : compptr->DCT_scaled_size = ssize;
173 : #endif
174 : }
175 :
176 : /* Recompute downsampled dimensions of components;
177 : * application needs to know these if using raw downsampled data.
178 : */
179 50 : for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
180 30 : ci++, compptr++) {
181 : /* Size in samples, after IDCT scaling */
182 30 : compptr->downsampled_width = (JDIMENSION)
183 60 : jdiv_round_up((long) cinfo->image_width *
184 30 : (long) (compptr->h_samp_factor * compptr->_DCT_scaled_size),
185 30 : (long) (cinfo->max_h_samp_factor * DCTSIZE));
186 30 : compptr->downsampled_height = (JDIMENSION)
187 60 : jdiv_round_up((long) cinfo->image_height *
188 30 : (long) (compptr->v_samp_factor * compptr->_DCT_scaled_size),
189 30 : (long) (cinfo->max_v_samp_factor * DCTSIZE));
190 : }
191 :
192 : #else /* !IDCT_SCALING_SUPPORTED */
193 :
194 : /* Hardwire it to "no scaling" */
195 : cinfo->output_width = cinfo->image_width;
196 : cinfo->output_height = cinfo->image_height;
197 : /* jdinput.c has already initialized DCT_scaled_size to DCTSIZE,
198 : * and has computed unscaled downsampled_width and downsampled_height.
199 : */
200 :
201 : #endif /* IDCT_SCALING_SUPPORTED */
202 :
203 : /* Report number of components in selected colorspace. */
204 : /* Probably this should be in the color conversion module... */
205 10 : switch (cinfo->out_color_space) {
206 : case JCS_GRAYSCALE:
207 0 : cinfo->out_color_components = 1;
208 0 : break;
209 : case JCS_RGB:
210 : case JCS_EXT_RGB:
211 : case JCS_EXT_RGBX:
212 : case JCS_EXT_BGR:
213 : case JCS_EXT_BGRX:
214 : case JCS_EXT_XBGR:
215 : case JCS_EXT_XRGB:
216 : case JCS_EXT_RGBA:
217 : case JCS_EXT_BGRA:
218 : case JCS_EXT_ABGR:
219 : case JCS_EXT_ARGB:
220 10 : cinfo->out_color_components = rgb_pixelsize[cinfo->out_color_space];
221 10 : break;
222 : case JCS_YCbCr:
223 0 : cinfo->out_color_components = 3;
224 0 : break;
225 : case JCS_CMYK:
226 : case JCS_YCCK:
227 0 : cinfo->out_color_components = 4;
228 0 : break;
229 : default: /* else must be same colorspace as in file */
230 0 : cinfo->out_color_components = cinfo->num_components;
231 0 : break;
232 : }
233 10 : cinfo->output_components = (cinfo->quantize_colors ? 1 :
234 : cinfo->out_color_components);
235 :
236 : /* See if upsampler will want to emit more than one row at a time */
237 10 : if (use_merged_upsample(cinfo))
238 0 : cinfo->rec_outbuf_height = cinfo->max_v_samp_factor;
239 : else
240 10 : cinfo->rec_outbuf_height = 1;
241 10 : }
242 :
243 :
244 : /*
245 : * Several decompression processes need to range-limit values to the range
246 : * 0..MAXJSAMPLE; the input value may fall somewhat outside this range
247 : * due to noise introduced by quantization, roundoff error, etc. These
248 : * processes are inner loops and need to be as fast as possible. On most
249 : * machines, particularly CPUs with pipelines or instruction prefetch,
250 : * a (subscript-check-less) C table lookup
251 : * x = sample_range_limit[x];
252 : * is faster than explicit tests
253 : * if (x < 0) x = 0;
254 : * else if (x > MAXJSAMPLE) x = MAXJSAMPLE;
255 : * These processes all use a common table prepared by the routine below.
256 : *
257 : * For most steps we can mathematically guarantee that the initial value
258 : * of x is within MAXJSAMPLE+1 of the legal range, so a table running from
259 : * -(MAXJSAMPLE+1) to 2*MAXJSAMPLE+1 is sufficient. But for the initial
260 : * limiting step (just after the IDCT), a wildly out-of-range value is
261 : * possible if the input data is corrupt. To avoid any chance of indexing
262 : * off the end of memory and getting a bad-pointer trap, we perform the
263 : * post-IDCT limiting thus:
264 : * x = range_limit[x & MASK];
265 : * where MASK is 2 bits wider than legal sample data, ie 10 bits for 8-bit
266 : * samples. Under normal circumstances this is more than enough range and
267 : * a correct output will be generated; with bogus input data the mask will
268 : * cause wraparound, and we will safely generate a bogus-but-in-range output.
269 : * For the post-IDCT step, we want to convert the data from signed to unsigned
270 : * representation by adding CENTERJSAMPLE at the same time that we limit it.
271 : * So the post-IDCT limiting table ends up looking like this:
272 : * CENTERJSAMPLE,CENTERJSAMPLE+1,...,MAXJSAMPLE,
273 : * MAXJSAMPLE (repeat 2*(MAXJSAMPLE+1)-CENTERJSAMPLE times),
274 : * 0 (repeat 2*(MAXJSAMPLE+1)-CENTERJSAMPLE times),
275 : * 0,1,...,CENTERJSAMPLE-1
276 : * Negative inputs select values from the upper half of the table after
277 : * masking.
278 : *
279 : * We can save some space by overlapping the start of the post-IDCT table
280 : * with the simpler range limiting table. The post-IDCT table begins at
281 : * sample_range_limit + CENTERJSAMPLE.
282 : *
283 : * Note that the table is allocated in near data space on PCs; it's small
284 : * enough and used often enough to justify this.
285 : */
286 :
287 : LOCAL(void)
288 5 : prepare_range_limit_table (j_decompress_ptr cinfo)
289 : /* Allocate and fill in the sample_range_limit table */
290 : {
291 : JSAMPLE * table;
292 : int i;
293 :
294 5 : table = (JSAMPLE *)
295 5 : (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
296 : (5 * (MAXJSAMPLE+1) + CENTERJSAMPLE) * SIZEOF(JSAMPLE));
297 5 : table += (MAXJSAMPLE+1); /* allow negative subscripts of simple table */
298 5 : cinfo->sample_range_limit = table;
299 : /* First segment of "simple" table: limit[x] = 0 for x < 0 */
300 5 : MEMZERO(table - (MAXJSAMPLE+1), (MAXJSAMPLE+1) * SIZEOF(JSAMPLE));
301 : /* Main part of "simple" table: limit[x] = x */
302 1285 : for (i = 0; i <= MAXJSAMPLE; i++)
303 1280 : table[i] = (JSAMPLE) i;
304 5 : table += CENTERJSAMPLE; /* Point to where post-IDCT table starts */
305 : /* End of simple table, rest of first half of post-IDCT table */
306 1925 : for (i = CENTERJSAMPLE; i < 2*(MAXJSAMPLE+1); i++)
307 1920 : table[i] = MAXJSAMPLE;
308 : /* Second half of post-IDCT table */
309 5 : MEMZERO(table + (2 * (MAXJSAMPLE+1)),
310 : (2 * (MAXJSAMPLE+1) - CENTERJSAMPLE) * SIZEOF(JSAMPLE));
311 5 : MEMCOPY(table + (4 * (MAXJSAMPLE+1) - CENTERJSAMPLE),
312 : cinfo->sample_range_limit, CENTERJSAMPLE * SIZEOF(JSAMPLE));
313 5 : }
314 :
315 :
316 : /*
317 : * Master selection of decompression modules.
318 : * This is done once at jpeg_start_decompress time. We determine
319 : * which modules will be used and give them appropriate initialization calls.
320 : * We also initialize the decompressor input side to begin consuming data.
321 : *
322 : * Since jpeg_read_header has finished, we know what is in the SOF
323 : * and (first) SOS markers. We also have all the application parameter
324 : * settings.
325 : */
326 :
327 : LOCAL(void)
328 5 : master_selection (j_decompress_ptr cinfo)
329 : {
330 5 : my_master_ptr master = (my_master_ptr) cinfo->master;
331 : boolean use_c_buffer;
332 : long samplesperrow;
333 : JDIMENSION jd_samplesperrow;
334 :
335 : /* Initialize dimensions and other stuff */
336 5 : jpeg_calc_output_dimensions(cinfo);
337 5 : prepare_range_limit_table(cinfo);
338 :
339 : /* Width of an output scanline must be representable as JDIMENSION. */
340 5 : samplesperrow = (long) cinfo->output_width * (long) cinfo->out_color_components;
341 5 : jd_samplesperrow = (JDIMENSION) samplesperrow;
342 5 : if ((long) jd_samplesperrow != samplesperrow)
343 0 : ERREXIT(cinfo, JERR_WIDTH_OVERFLOW);
344 :
345 : /* Initialize my private state */
346 5 : master->pass_number = 0;
347 5 : master->using_merged_upsample = use_merged_upsample(cinfo);
348 :
349 : /* Color quantizer selection */
350 5 : master->quantizer_1pass = NULL;
351 5 : master->quantizer_2pass = NULL;
352 : /* No mode changes if not using buffered-image mode. */
353 5 : if (! cinfo->quantize_colors || ! cinfo->buffered_image) {
354 5 : cinfo->enable_1pass_quant = FALSE;
355 5 : cinfo->enable_external_quant = FALSE;
356 5 : cinfo->enable_2pass_quant = FALSE;
357 : }
358 5 : if (cinfo->quantize_colors) {
359 0 : if (cinfo->raw_data_out)
360 0 : ERREXIT(cinfo, JERR_NOTIMPL);
361 : /* 2-pass quantizer only works in 3-component color space. */
362 0 : if (cinfo->out_color_components != 3) {
363 0 : cinfo->enable_1pass_quant = TRUE;
364 0 : cinfo->enable_external_quant = FALSE;
365 0 : cinfo->enable_2pass_quant = FALSE;
366 0 : cinfo->colormap = NULL;
367 0 : } else if (cinfo->colormap != NULL) {
368 0 : cinfo->enable_external_quant = TRUE;
369 0 : } else if (cinfo->two_pass_quantize) {
370 0 : cinfo->enable_2pass_quant = TRUE;
371 : } else {
372 0 : cinfo->enable_1pass_quant = TRUE;
373 : }
374 :
375 0 : if (cinfo->enable_1pass_quant) {
376 : #ifdef QUANT_1PASS_SUPPORTED
377 0 : jinit_1pass_quantizer(cinfo);
378 0 : master->quantizer_1pass = cinfo->cquantize;
379 : #else
380 : ERREXIT(cinfo, JERR_NOT_COMPILED);
381 : #endif
382 : }
383 :
384 : /* We use the 2-pass code to map to external colormaps. */
385 0 : if (cinfo->enable_2pass_quant || cinfo->enable_external_quant) {
386 : #ifdef QUANT_2PASS_SUPPORTED
387 0 : jinit_2pass_quantizer(cinfo);
388 0 : master->quantizer_2pass = cinfo->cquantize;
389 : #else
390 : ERREXIT(cinfo, JERR_NOT_COMPILED);
391 : #endif
392 : }
393 : /* If both quantizers are initialized, the 2-pass one is left active;
394 : * this is necessary for starting with quantization to an external map.
395 : */
396 : }
397 :
398 : /* Post-processing: in particular, color conversion first */
399 5 : if (! cinfo->raw_data_out) {
400 5 : if (master->using_merged_upsample) {
401 : #ifdef UPSAMPLE_MERGING_SUPPORTED
402 0 : jinit_merged_upsampler(cinfo); /* does color conversion too */
403 : #else
404 : ERREXIT(cinfo, JERR_NOT_COMPILED);
405 : #endif
406 : } else {
407 5 : jinit_color_deconverter(cinfo);
408 5 : jinit_upsampler(cinfo);
409 : }
410 5 : jinit_d_post_controller(cinfo, cinfo->enable_2pass_quant);
411 : }
412 : /* Inverse DCT */
413 5 : jinit_inverse_dct(cinfo);
414 : /* Entropy decoding: either Huffman or arithmetic coding. */
415 5 : if (cinfo->arith_code) {
416 : #ifdef D_ARITH_CODING_SUPPORTED
417 : jinit_arith_decoder(cinfo);
418 : #else
419 0 : ERREXIT(cinfo, JERR_ARITH_NOTIMPL);
420 : #endif
421 : } else {
422 5 : if (cinfo->progressive_mode) {
423 : #ifdef D_PROGRESSIVE_SUPPORTED
424 0 : jinit_phuff_decoder(cinfo);
425 : #else
426 : ERREXIT(cinfo, JERR_NOT_COMPILED);
427 : #endif
428 : } else
429 5 : jinit_huff_decoder(cinfo);
430 : }
431 :
432 : /* Initialize principal buffer controllers. */
433 5 : use_c_buffer = cinfo->inputctl->has_multiple_scans || cinfo->buffered_image;
434 5 : jinit_d_coef_controller(cinfo, use_c_buffer);
435 :
436 5 : if (! cinfo->raw_data_out)
437 5 : jinit_d_main_controller(cinfo, FALSE /* never need full buffer here */);
438 :
439 : /* We can now tell the memory manager to allocate virtual arrays. */
440 5 : (*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo);
441 :
442 : /* Initialize input side of decompressor to consume first scan. */
443 5 : (*cinfo->inputctl->start_input_pass) (cinfo);
444 :
445 : #ifdef D_MULTISCAN_FILES_SUPPORTED
446 : /* If jpeg_start_decompress will read the whole file, initialize
447 : * progress monitoring appropriately. The input step is counted
448 : * as one pass.
449 : */
450 5 : if (cinfo->progress != NULL && ! cinfo->buffered_image &&
451 0 : cinfo->inputctl->has_multiple_scans) {
452 : int nscans;
453 : /* Estimate number of scans to set pass_limit. */
454 0 : if (cinfo->progressive_mode) {
455 : /* Arbitrarily estimate 2 interleaved DC scans + 3 AC scans/component. */
456 0 : nscans = 2 + 3 * cinfo->num_components;
457 : } else {
458 : /* For a nonprogressive multiscan file, estimate 1 scan per component. */
459 0 : nscans = cinfo->num_components;
460 : }
461 0 : cinfo->progress->pass_counter = 0L;
462 0 : cinfo->progress->pass_limit = (long) cinfo->total_iMCU_rows * nscans;
463 0 : cinfo->progress->completed_passes = 0;
464 0 : cinfo->progress->total_passes = (cinfo->enable_2pass_quant ? 3 : 2);
465 : /* Count the input pass as done */
466 0 : master->pass_number++;
467 : }
468 : #endif /* D_MULTISCAN_FILES_SUPPORTED */
469 5 : }
470 :
471 :
472 : /*
473 : * Per-pass setup.
474 : * This is called at the beginning of each output pass. We determine which
475 : * modules will be active during this pass and give them appropriate
476 : * start_pass calls. We also set is_dummy_pass to indicate whether this
477 : * is a "real" output pass or a dummy pass for color quantization.
478 : * (In the latter case, jdapistd.c will crank the pass to completion.)
479 : */
480 :
481 : METHODDEF(void)
482 5 : prepare_for_output_pass (j_decompress_ptr cinfo)
483 : {
484 5 : my_master_ptr master = (my_master_ptr) cinfo->master;
485 :
486 5 : if (master->pub.is_dummy_pass) {
487 : #ifdef QUANT_2PASS_SUPPORTED
488 : /* Final pass of 2-pass quantization */
489 0 : master->pub.is_dummy_pass = FALSE;
490 0 : (*cinfo->cquantize->start_pass) (cinfo, FALSE);
491 0 : (*cinfo->post->start_pass) (cinfo, JBUF_CRANK_DEST);
492 0 : (*cinfo->main->start_pass) (cinfo, JBUF_CRANK_DEST);
493 : #else
494 : ERREXIT(cinfo, JERR_NOT_COMPILED);
495 : #endif /* QUANT_2PASS_SUPPORTED */
496 : } else {
497 5 : if (cinfo->quantize_colors && cinfo->colormap == NULL) {
498 : /* Select new quantization method */
499 0 : if (cinfo->two_pass_quantize && cinfo->enable_2pass_quant) {
500 0 : cinfo->cquantize = master->quantizer_2pass;
501 0 : master->pub.is_dummy_pass = TRUE;
502 0 : } else if (cinfo->enable_1pass_quant) {
503 0 : cinfo->cquantize = master->quantizer_1pass;
504 : } else {
505 0 : ERREXIT(cinfo, JERR_MODE_CHANGE);
506 : }
507 : }
508 5 : (*cinfo->idct->start_pass) (cinfo);
509 5 : (*cinfo->coef->start_output_pass) (cinfo);
510 5 : if (! cinfo->raw_data_out) {
511 5 : if (! master->using_merged_upsample)
512 5 : (*cinfo->cconvert->start_pass) (cinfo);
513 5 : (*cinfo->upsample->start_pass) (cinfo);
514 5 : if (cinfo->quantize_colors)
515 0 : (*cinfo->cquantize->start_pass) (cinfo, master->pub.is_dummy_pass);
516 10 : (*cinfo->post->start_pass) (cinfo,
517 5 : (master->pub.is_dummy_pass ? JBUF_SAVE_AND_PASS : JBUF_PASS_THRU));
518 5 : (*cinfo->main->start_pass) (cinfo, JBUF_PASS_THRU);
519 : }
520 : }
521 :
522 : /* Set up progress monitor's pass info if present */
523 5 : if (cinfo->progress != NULL) {
524 0 : cinfo->progress->completed_passes = master->pass_number;
525 0 : cinfo->progress->total_passes = master->pass_number +
526 0 : (master->pub.is_dummy_pass ? 2 : 1);
527 : /* In buffered-image mode, we assume one more output pass if EOI not
528 : * yet reached, but no more passes if EOI has been reached.
529 : */
530 0 : if (cinfo->buffered_image && ! cinfo->inputctl->eoi_reached) {
531 0 : cinfo->progress->total_passes += (cinfo->enable_2pass_quant ? 2 : 1);
532 : }
533 : }
534 5 : }
535 :
536 :
537 : /*
538 : * Finish up at end of an output pass.
539 : */
540 :
541 : METHODDEF(void)
542 5 : finish_output_pass (j_decompress_ptr cinfo)
543 : {
544 5 : my_master_ptr master = (my_master_ptr) cinfo->master;
545 :
546 5 : if (cinfo->quantize_colors)
547 0 : (*cinfo->cquantize->finish_pass) (cinfo);
548 5 : master->pass_number++;
549 5 : }
550 :
551 :
552 : #ifdef D_MULTISCAN_FILES_SUPPORTED
553 :
554 : /*
555 : * Switch to a new external colormap between output passes.
556 : */
557 :
558 : GLOBAL(void)
559 0 : jpeg_new_colormap (j_decompress_ptr cinfo)
560 : {
561 0 : my_master_ptr master = (my_master_ptr) cinfo->master;
562 :
563 : /* Prevent application from calling me at wrong times */
564 0 : if (cinfo->global_state != DSTATE_BUFIMAGE)
565 0 : ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
566 :
567 0 : if (cinfo->quantize_colors && cinfo->enable_external_quant &&
568 0 : cinfo->colormap != NULL) {
569 : /* Select 2-pass quantizer for external colormap use */
570 0 : cinfo->cquantize = master->quantizer_2pass;
571 : /* Notify quantizer of colormap change */
572 0 : (*cinfo->cquantize->new_color_map) (cinfo);
573 0 : master->pub.is_dummy_pass = FALSE; /* just in case */
574 : } else
575 0 : ERREXIT(cinfo, JERR_MODE_CHANGE);
576 0 : }
577 :
578 : #endif /* D_MULTISCAN_FILES_SUPPORTED */
579 :
580 :
581 : /*
582 : * Initialize master decompression control and select active modules.
583 : * This is performed at the start of jpeg_start_decompress.
584 : */
585 :
586 : GLOBAL(void)
587 5 : jinit_master_decompress (j_decompress_ptr cinfo)
588 : {
589 : my_master_ptr master;
590 :
591 5 : master = (my_master_ptr)
592 5 : (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
593 : SIZEOF(my_decomp_master));
594 5 : cinfo->master = (struct jpeg_decomp_master *) master;
595 5 : master->pub.prepare_for_output_pass = prepare_for_output_pass;
596 5 : master->pub.finish_output_pass = finish_output_pass;
597 :
598 5 : master->pub.is_dummy_pass = FALSE;
599 :
600 5 : master_selection(cinfo);
601 5 : }
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