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comparison mupdf-source/thirdparty/libjpeg/jdapimin.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 * jdapimin.c
3 *
4 * Copyright (C) 1994-1998, Thomas G. Lane.
5 * Modified 2009-2020 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 application interface code for the decompression half
10 * of the JPEG library. These are the "minimum" API routines that may be
11 * needed in either the normal full-decompression case or the
12 * transcoding-only case.
13 *
14 * Most of the routines intended to be called directly by an application
15 * are in this file or in jdapistd.c. But also see jcomapi.c for routines
16 * shared by compression and decompression, and jdtrans.c for the transcoding
17 * case.
18 */
19
20 #define JPEG_INTERNALS
21 #include "jinclude.h"
22 #include "jpeglib.h"
23
24
25 /*
26 * Initialization of a JPEG decompression object.
27 * The error manager must already be set up (in case memory manager fails).
28 */
29
30 GLOBAL(void)
31 jpeg_CreateDecompress (j_decompress_ptr cinfo, int version, size_t structsize)
32 {
33 int i;
34
35 /* Guard against version mismatches between library and caller. */
36 cinfo->mem = NULL; /* so jpeg_destroy knows mem mgr not called */
37 if (version != JPEG_LIB_VERSION)
38 ERREXIT2(cinfo, JERR_BAD_LIB_VERSION, JPEG_LIB_VERSION, version);
39 if (structsize != SIZEOF(struct jpeg_decompress_struct))
40 ERREXIT2(cinfo, JERR_BAD_STRUCT_SIZE,
41 (int) SIZEOF(struct jpeg_decompress_struct), (int) structsize);
42
43 /* For debugging purposes, we zero the whole master structure.
44 * But the application has already set the err pointer, and may have set
45 * client_data, so we have to save and restore those fields.
46 * Note: if application hasn't set client_data, tools like Purify may
47 * complain here.
48 */
49 {
50 struct jpeg_error_mgr * err = cinfo->err;
51 void * client_data = cinfo->client_data; /* ignore Purify complaint here */
52 MEMZERO(cinfo, SIZEOF(struct jpeg_decompress_struct));
53 cinfo->err = err;
54 cinfo->client_data = client_data;
55 }
56 cinfo->is_decompressor = TRUE;
57
58 /* Initialize a memory manager instance for this object */
59 jinit_memory_mgr((j_common_ptr) cinfo);
60
61 /* Zero out pointers to permanent structures. */
62 cinfo->progress = NULL;
63 cinfo->src = NULL;
64
65 for (i = 0; i < NUM_QUANT_TBLS; i++)
66 cinfo->quant_tbl_ptrs[i] = NULL;
67
68 for (i = 0; i < NUM_HUFF_TBLS; i++) {
69 cinfo->dc_huff_tbl_ptrs[i] = NULL;
70 cinfo->ac_huff_tbl_ptrs[i] = NULL;
71 }
72
73 /* Initialize marker processor so application can override methods
74 * for COM, APPn markers before calling jpeg_read_header.
75 */
76 cinfo->marker_list = NULL;
77 jinit_marker_reader(cinfo);
78
79 /* And initialize the overall input controller. */
80 jinit_input_controller(cinfo);
81
82 /* OK, I'm ready */
83 cinfo->global_state = DSTATE_START;
84 }
85
86
87 /*
88 * Destruction of a JPEG decompression object
89 */
90
91 GLOBAL(void)
92 jpeg_destroy_decompress (j_decompress_ptr cinfo)
93 {
94 jpeg_destroy((j_common_ptr) cinfo); /* use common routine */
95 }
96
97
98 /*
99 * Abort processing of a JPEG decompression operation,
100 * but don't destroy the object itself.
101 */
102
103 GLOBAL(void)
104 jpeg_abort_decompress (j_decompress_ptr cinfo)
105 {
106 jpeg_abort((j_common_ptr) cinfo); /* use common routine */
107 }
108
109
110 /*
111 * Set default decompression parameters.
112 */
113
114 LOCAL(void)
115 default_decompress_parms (j_decompress_ptr cinfo)
116 {
117 int cid0, cid1, cid2, cid3;
118
119 /* Guess the input colorspace, and set output colorspace accordingly. */
120 /* Note application may override our guesses. */
121 switch (cinfo->num_components) {
122 case 1:
123 cinfo->jpeg_color_space = JCS_GRAYSCALE;
124 cinfo->out_color_space = JCS_GRAYSCALE;
125 break;
126
127 case 3:
128 cid0 = cinfo->comp_info[0].component_id;
129 cid1 = cinfo->comp_info[1].component_id;
130 cid2 = cinfo->comp_info[2].component_id;
131
132 /* For robust detection of standard colorspaces
133 * regardless of the presence of special markers,
134 * check component IDs from SOF marker first.
135 */
136 if (cid0 == 0x01 && cid1 == 0x02 && cid2 == 0x03)
137 cinfo->jpeg_color_space = JCS_YCbCr;
138 else if (cid0 == 0x01 && cid1 == 0x22 && cid2 == 0x23)
139 cinfo->jpeg_color_space = JCS_BG_YCC;
140 else if (cid0 == 0x52 && cid1 == 0x47 && cid2 == 0x42)
141 cinfo->jpeg_color_space = JCS_RGB; /* ASCII 'R', 'G', 'B' */
142 else if (cid0 == 0x72 && cid1 == 0x67 && cid2 == 0x62)
143 cinfo->jpeg_color_space = JCS_BG_RGB; /* ASCII 'r', 'g', 'b' */
144 else if (cinfo->saw_JFIF_marker)
145 cinfo->jpeg_color_space = JCS_YCbCr; /* assume it's YCbCr */
146 else if (cinfo->saw_Adobe_marker) {
147 switch (cinfo->Adobe_transform) {
148 case 0:
149 cinfo->jpeg_color_space = JCS_RGB;
150 break;
151 case 1:
152 cinfo->jpeg_color_space = JCS_YCbCr;
153 break;
154 default:
155 WARNMS1(cinfo, JWRN_ADOBE_XFORM, cinfo->Adobe_transform);
156 cinfo->jpeg_color_space = JCS_YCbCr; /* assume it's YCbCr */
157 }
158 } else {
159 TRACEMS3(cinfo, 1, JTRC_UNKNOWN_IDS, cid0, cid1, cid2);
160 cinfo->jpeg_color_space = JCS_YCbCr; /* assume it's YCbCr */
161 }
162 /* Always guess RGB is proper output colorspace. */
163 cinfo->out_color_space = JCS_RGB;
164 break;
165
166 case 4:
167 cid0 = cinfo->comp_info[0].component_id;
168 cid1 = cinfo->comp_info[1].component_id;
169 cid2 = cinfo->comp_info[2].component_id;
170 cid3 = cinfo->comp_info[3].component_id;
171
172 /* For robust detection of standard colorspaces
173 * regardless of the presence of special markers,
174 * check component IDs from SOF marker first.
175 */
176 if (cid0 == 0x01 && cid1 == 0x02 && cid2 == 0x03 && cid3 == 0x04)
177 cinfo->jpeg_color_space = JCS_YCCK;
178 else if (cid0 == 0x43 && cid1 == 0x4D && cid2 == 0x59 && cid3 == 0x4B)
179 cinfo->jpeg_color_space = JCS_CMYK; /* ASCII 'C', 'M', 'Y', 'K' */
180 else if (cinfo->saw_Adobe_marker) {
181 switch (cinfo->Adobe_transform) {
182 case 0:
183 cinfo->jpeg_color_space = JCS_CMYK;
184 break;
185 case 2:
186 cinfo->jpeg_color_space = JCS_YCCK;
187 break;
188 default:
189 WARNMS1(cinfo, JWRN_ADOBE_XFORM, cinfo->Adobe_transform);
190 cinfo->jpeg_color_space = JCS_YCCK; /* assume it's YCCK */
191 }
192 } else {
193 /* Unknown IDs and no special markers, assume straight CMYK. */
194 cinfo->jpeg_color_space = JCS_CMYK;
195 }
196 cinfo->out_color_space = JCS_CMYK;
197 break;
198
199 default:
200 cinfo->jpeg_color_space = JCS_UNKNOWN;
201 cinfo->out_color_space = JCS_UNKNOWN;
202 }
203
204 /* Set defaults for other decompression parameters. */
205 cinfo->scale_num = cinfo->block_size; /* 1:1 scaling */
206 cinfo->scale_denom = cinfo->block_size;
207 cinfo->output_gamma = 1.0;
208 cinfo->buffered_image = FALSE;
209 cinfo->raw_data_out = FALSE;
210 cinfo->dct_method = JDCT_DEFAULT;
211 cinfo->do_fancy_upsampling = TRUE;
212 cinfo->do_block_smoothing = TRUE;
213 cinfo->quantize_colors = FALSE;
214 /* We set these in case application only sets quantize_colors. */
215 cinfo->dither_mode = JDITHER_FS;
216 #ifdef QUANT_2PASS_SUPPORTED
217 cinfo->two_pass_quantize = TRUE;
218 #else
219 cinfo->two_pass_quantize = FALSE;
220 #endif
221 cinfo->desired_number_of_colors = 256;
222 cinfo->colormap = NULL;
223 /* Initialize for no mode change in buffered-image mode. */
224 cinfo->enable_1pass_quant = FALSE;
225 cinfo->enable_external_quant = FALSE;
226 cinfo->enable_2pass_quant = FALSE;
227 }
228
229
230 /*
231 * Decompression startup: read start of JPEG datastream to see what's there.
232 * Need only initialize JPEG object and supply a data source before calling.
233 *
234 * This routine will read as far as the first SOS marker (ie, actual start of
235 * compressed data), and will save all tables and parameters in the JPEG
236 * object. It will also initialize the decompression parameters to default
237 * values, and finally return JPEG_HEADER_OK. On return, the application may
238 * adjust the decompression parameters and then call jpeg_start_decompress.
239 * (Or, if the application only wanted to determine the image parameters,
240 * the data need not be decompressed. In that case, call jpeg_abort or
241 * jpeg_destroy to release any temporary space.)
242 * If an abbreviated (tables only) datastream is presented, the routine will
243 * return JPEG_HEADER_TABLES_ONLY upon reaching EOI. The application may then
244 * re-use the JPEG object to read the abbreviated image datastream(s).
245 * It is unnecessary (but OK) to call jpeg_abort in this case.
246 * The JPEG_SUSPENDED return code only occurs if the data source module
247 * requests suspension of the decompressor. In this case the application
248 * should load more source data and then re-call jpeg_read_header to resume
249 * processing.
250 * If a non-suspending data source is used and require_image is TRUE, then the
251 * return code need not be inspected since only JPEG_HEADER_OK is possible.
252 *
253 * This routine is now just a front end to jpeg_consume_input, with some
254 * extra error checking.
255 */
256
257 GLOBAL(int)
258 jpeg_read_header (j_decompress_ptr cinfo, boolean require_image)
259 {
260 int retcode;
261
262 if (cinfo->global_state != DSTATE_START &&
263 cinfo->global_state != DSTATE_INHEADER)
264 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
265
266 retcode = jpeg_consume_input(cinfo);
267
268 switch (retcode) {
269 case JPEG_REACHED_SOS:
270 retcode = JPEG_HEADER_OK;
271 break;
272 case JPEG_REACHED_EOI:
273 if (require_image) /* Complain if application wanted an image */
274 ERREXIT(cinfo, JERR_NO_IMAGE);
275 /* Reset to start state; it would be safer to require the application to
276 * call jpeg_abort, but we can't change it now for compatibility reasons.
277 * A side effect is to free any temporary memory (there shouldn't be any).
278 */
279 jpeg_abort((j_common_ptr) cinfo); /* sets state = DSTATE_START */
280 retcode = JPEG_HEADER_TABLES_ONLY;
281 break;
282 case JPEG_SUSPENDED:
283 /* no work */
284 break;
285 }
286
287 return retcode;
288 }
289
290
291 /*
292 * Consume data in advance of what the decompressor requires.
293 * This can be called at any time once the decompressor object has
294 * been created and a data source has been set up.
295 *
296 * This routine is essentially a state machine that handles a couple
297 * of critical state-transition actions, namely initial setup and
298 * transition from header scanning to ready-for-start_decompress.
299 * All the actual input is done via the input controller's consume_input
300 * method.
301 */
302
303 GLOBAL(int)
304 jpeg_consume_input (j_decompress_ptr cinfo)
305 {
306 int retcode = JPEG_SUSPENDED;
307
308 /* NB: every possible DSTATE value should be listed in this switch */
309 switch (cinfo->global_state) {
310 case DSTATE_START:
311 /* Start-of-datastream actions: reset appropriate modules */
312 (*cinfo->inputctl->reset_input_controller) (cinfo);
313 /* Initialize application's data source module */
314 (*cinfo->src->init_source) (cinfo);
315 cinfo->global_state = DSTATE_INHEADER;
316 /*FALLTHROUGH*/
317 case DSTATE_INHEADER:
318 retcode = (*cinfo->inputctl->consume_input) (cinfo);
319 if (retcode == JPEG_REACHED_SOS) { /* Found SOS, prepare to decompress */
320 /* Set up default parameters based on header data */
321 default_decompress_parms(cinfo);
322 /* Set global state: ready for start_decompress */
323 cinfo->global_state = DSTATE_READY;
324 }
325 break;
326 case DSTATE_READY:
327 /* Can't advance past first SOS until start_decompress is called */
328 retcode = JPEG_REACHED_SOS;
329 break;
330 case DSTATE_PRELOAD:
331 case DSTATE_PRESCAN:
332 case DSTATE_SCANNING:
333 case DSTATE_RAW_OK:
334 case DSTATE_BUFIMAGE:
335 case DSTATE_BUFPOST:
336 case DSTATE_STOPPING:
337 retcode = (*cinfo->inputctl->consume_input) (cinfo);
338 break;
339 default:
340 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
341 }
342 return retcode;
343 }
344
345
346 /*
347 * Have we finished reading the input file?
348 */
349
350 GLOBAL(boolean)
351 jpeg_input_complete (j_decompress_ptr cinfo)
352 {
353 /* Check for valid jpeg object */
354 if (cinfo->global_state < DSTATE_START ||
355 cinfo->global_state > DSTATE_STOPPING)
356 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
357 return cinfo->inputctl->eoi_reached;
358 }
359
360
361 /*
362 * Is there more than one scan?
363 */
364
365 GLOBAL(boolean)
366 jpeg_has_multiple_scans (j_decompress_ptr cinfo)
367 {
368 /* Only valid after jpeg_read_header completes */
369 if (cinfo->global_state < DSTATE_READY ||
370 cinfo->global_state > DSTATE_STOPPING)
371 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
372 return cinfo->inputctl->has_multiple_scans;
373 }
374
375
376 /*
377 * Finish JPEG decompression.
378 *
379 * This will normally just verify the file trailer and release temp storage.
380 *
381 * Returns FALSE if suspended. The return value need be inspected only if
382 * a suspending data source is used.
383 */
384
385 GLOBAL(boolean)
386 jpeg_finish_decompress (j_decompress_ptr cinfo)
387 {
388 if ((cinfo->global_state == DSTATE_SCANNING ||
389 cinfo->global_state == DSTATE_RAW_OK) && ! cinfo->buffered_image) {
390 /* Terminate final pass of non-buffered mode */
391 if (cinfo->output_scanline < cinfo->output_height)
392 ERREXIT(cinfo, JERR_TOO_LITTLE_DATA);
393 (*cinfo->master->finish_output_pass) (cinfo);
394 cinfo->global_state = DSTATE_STOPPING;
395 } else if (cinfo->global_state == DSTATE_BUFIMAGE) {
396 /* Finishing after a buffered-image operation */
397 cinfo->global_state = DSTATE_STOPPING;
398 } else if (cinfo->global_state != DSTATE_STOPPING) {
399 /* STOPPING = repeat call after a suspension, anything else is error */
400 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
401 }
402 /* Read until EOI */
403 while (! cinfo->inputctl->eoi_reached) {
404 if ((*cinfo->inputctl->consume_input) (cinfo) == JPEG_SUSPENDED)
405 return FALSE; /* Suspend, come back later */
406 }
407 /* Do final cleanup */
408 (*cinfo->src->term_source) (cinfo);
409 /* We can use jpeg_abort to release memory and reset global_state */
410 jpeg_abort((j_common_ptr) cinfo);
411 return TRUE;
412 }