1 : /*
2 : * jcapimin.c
3 : *
4 : * Copyright (C) 1994-1998, 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 application interface code for the compression half
10 : * of the JPEG library. These are the "minimum" API routines that may be
11 : * needed in either the normal full-compression case or the transcoding-only
12 : * case.
13 : *
14 : * Most of the routines intended to be called directly by an application
15 : * are in this file or in jcapistd.c. But also see jcparam.c for
16 : * parameter-setup helper routines, jcomapi.c for routines shared by
17 : * compression and decompression, and jctrans.c for the transcoding case.
18 : */
19 :
20 : #define JPEG_INTERNALS
21 : #include "jinclude.h"
22 : #include "jpeglib.h"
23 :
24 :
25 : /*
26 : * Initialization of a JPEG compression object.
27 : * The error manager must already be set up (in case memory manager fails).
28 : */
29 :
30 : GLOBAL(void)
31 3 : jpeg_CreateCompress (j_compress_ptr cinfo, int version, size_t structsize)
32 : {
33 : int i;
34 :
35 : /* Guard against version mismatches between library and caller. */
36 3 : cinfo->mem = NULL; /* so jpeg_destroy knows mem mgr not called */
37 3 : if (version != JPEG_LIB_VERSION)
38 0 : ERREXIT2(cinfo, JERR_BAD_LIB_VERSION, JPEG_LIB_VERSION, version);
39 3 : if (structsize != SIZEOF(struct jpeg_compress_struct))
40 0 : ERREXIT2(cinfo, JERR_BAD_STRUCT_SIZE,
41 : (int) SIZEOF(struct jpeg_compress_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 3 : struct jpeg_error_mgr * err = cinfo->err;
51 3 : void * client_data = cinfo->client_data; /* ignore Purify complaint here */
52 3 : MEMZERO(cinfo, SIZEOF(struct jpeg_compress_struct));
53 3 : cinfo->err = err;
54 3 : cinfo->client_data = client_data;
55 : }
56 3 : cinfo->is_decompressor = FALSE;
57 :
58 : /* Initialize a memory manager instance for this object */
59 3 : jinit_memory_mgr((j_common_ptr) cinfo);
60 :
61 : /* Zero out pointers to permanent structures. */
62 3 : cinfo->progress = NULL;
63 3 : cinfo->dest = NULL;
64 :
65 3 : cinfo->comp_info = NULL;
66 :
67 15 : for (i = 0; i < NUM_QUANT_TBLS; i++) {
68 12 : cinfo->quant_tbl_ptrs[i] = NULL;
69 : #if JPEG_LIB_VERSION >= 70
70 : cinfo->q_scale_factor[i] = 100;
71 : #endif
72 : }
73 :
74 15 : for (i = 0; i < NUM_HUFF_TBLS; i++) {
75 12 : cinfo->dc_huff_tbl_ptrs[i] = NULL;
76 12 : cinfo->ac_huff_tbl_ptrs[i] = NULL;
77 : }
78 :
79 : #if JPEG_LIB_VERSION >= 80
80 : /* Must do it here for emit_dqt in case jpeg_write_tables is used */
81 : cinfo->block_size = DCTSIZE;
82 : cinfo->natural_order = jpeg_natural_order;
83 : cinfo->lim_Se = DCTSIZE2-1;
84 : #endif
85 :
86 3 : cinfo->script_space = NULL;
87 :
88 3 : cinfo->input_gamma = 1.0; /* in case application forgets */
89 :
90 : /* OK, I'm ready */
91 3 : cinfo->global_state = CSTATE_START;
92 3 : }
93 :
94 :
95 : /*
96 : * Destruction of a JPEG compression object
97 : */
98 :
99 : GLOBAL(void)
100 3 : jpeg_destroy_compress (j_compress_ptr cinfo)
101 : {
102 3 : jpeg_destroy((j_common_ptr) cinfo); /* use common routine */
103 3 : }
104 :
105 :
106 : /*
107 : * Abort processing of a JPEG compression operation,
108 : * but don't destroy the object itself.
109 : */
110 :
111 : GLOBAL(void)
112 0 : jpeg_abort_compress (j_compress_ptr cinfo)
113 : {
114 0 : jpeg_abort((j_common_ptr) cinfo); /* use common routine */
115 0 : }
116 :
117 :
118 : /*
119 : * Forcibly suppress or un-suppress all quantization and Huffman tables.
120 : * Marks all currently defined tables as already written (if suppress)
121 : * or not written (if !suppress). This will control whether they get emitted
122 : * by a subsequent jpeg_start_compress call.
123 : *
124 : * This routine is exported for use by applications that want to produce
125 : * abbreviated JPEG datastreams. It logically belongs in jcparam.c, but
126 : * since it is called by jpeg_start_compress, we put it here --- otherwise
127 : * jcparam.o would be linked whether the application used it or not.
128 : */
129 :
130 : GLOBAL(void)
131 3 : jpeg_suppress_tables (j_compress_ptr cinfo, boolean suppress)
132 : {
133 : int i;
134 : JQUANT_TBL * qtbl;
135 : JHUFF_TBL * htbl;
136 :
137 15 : for (i = 0; i < NUM_QUANT_TBLS; i++) {
138 12 : if ((qtbl = cinfo->quant_tbl_ptrs[i]) != NULL)
139 6 : qtbl->sent_table = suppress;
140 : }
141 :
142 15 : for (i = 0; i < NUM_HUFF_TBLS; i++) {
143 12 : if ((htbl = cinfo->dc_huff_tbl_ptrs[i]) != NULL)
144 6 : htbl->sent_table = suppress;
145 12 : if ((htbl = cinfo->ac_huff_tbl_ptrs[i]) != NULL)
146 6 : htbl->sent_table = suppress;
147 : }
148 3 : }
149 :
150 :
151 : /*
152 : * Finish JPEG compression.
153 : *
154 : * If a multipass operating mode was selected, this may do a great deal of
155 : * work including most of the actual output.
156 : */
157 :
158 : GLOBAL(void)
159 3 : jpeg_finish_compress (j_compress_ptr cinfo)
160 : {
161 : JDIMENSION iMCU_row;
162 :
163 3 : if (cinfo->global_state == CSTATE_SCANNING ||
164 0 : cinfo->global_state == CSTATE_RAW_OK) {
165 : /* Terminate first pass */
166 3 : if (cinfo->next_scanline < cinfo->image_height)
167 0 : ERREXIT(cinfo, JERR_TOO_LITTLE_DATA);
168 3 : (*cinfo->master->finish_pass) (cinfo);
169 0 : } else if (cinfo->global_state != CSTATE_WRCOEFS)
170 0 : ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
171 : /* Perform any remaining passes */
172 6 : while (! cinfo->master->is_last_pass) {
173 0 : (*cinfo->master->prepare_for_pass) (cinfo);
174 0 : for (iMCU_row = 0; iMCU_row < cinfo->total_iMCU_rows; iMCU_row++) {
175 0 : if (cinfo->progress != NULL) {
176 0 : cinfo->progress->pass_counter = (long) iMCU_row;
177 0 : cinfo->progress->pass_limit = (long) cinfo->total_iMCU_rows;
178 0 : (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
179 : }
180 : /* We bypass the main controller and invoke coef controller directly;
181 : * all work is being done from the coefficient buffer.
182 : */
183 0 : if (! (*cinfo->coef->compress_data) (cinfo, (JSAMPIMAGE) NULL))
184 0 : ERREXIT(cinfo, JERR_CANT_SUSPEND);
185 : }
186 0 : (*cinfo->master->finish_pass) (cinfo);
187 : }
188 : /* Write EOI, do final cleanup */
189 3 : (*cinfo->marker->write_file_trailer) (cinfo);
190 3 : (*cinfo->dest->term_destination) (cinfo);
191 : /* We can use jpeg_abort to release memory and reset global_state */
192 3 : jpeg_abort((j_common_ptr) cinfo);
193 3 : }
194 :
195 :
196 : /*
197 : * Write a special marker.
198 : * This is only recommended for writing COM or APPn markers.
199 : * Must be called after jpeg_start_compress() and before
200 : * first call to jpeg_write_scanlines() or jpeg_write_raw_data().
201 : */
202 :
203 : GLOBAL(void)
204 0 : jpeg_write_marker (j_compress_ptr cinfo, int marker,
205 : const JOCTET *dataptr, unsigned int datalen)
206 : {
207 : JMETHOD(void, write_marker_byte, (j_compress_ptr info, int val));
208 :
209 0 : if (cinfo->next_scanline != 0 ||
210 0 : (cinfo->global_state != CSTATE_SCANNING &&
211 0 : cinfo->global_state != CSTATE_RAW_OK &&
212 0 : cinfo->global_state != CSTATE_WRCOEFS))
213 0 : ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
214 :
215 0 : (*cinfo->marker->write_marker_header) (cinfo, marker, datalen);
216 0 : write_marker_byte = cinfo->marker->write_marker_byte; /* copy for speed */
217 0 : while (datalen--) {
218 0 : (*write_marker_byte) (cinfo, *dataptr);
219 0 : dataptr++;
220 : }
221 0 : }
222 :
223 : /* Same, but piecemeal. */
224 :
225 : GLOBAL(void)
226 0 : jpeg_write_m_header (j_compress_ptr cinfo, int marker, unsigned int datalen)
227 : {
228 0 : if (cinfo->next_scanline != 0 ||
229 0 : (cinfo->global_state != CSTATE_SCANNING &&
230 0 : cinfo->global_state != CSTATE_RAW_OK &&
231 0 : cinfo->global_state != CSTATE_WRCOEFS))
232 0 : ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
233 :
234 0 : (*cinfo->marker->write_marker_header) (cinfo, marker, datalen);
235 0 : }
236 :
237 : GLOBAL(void)
238 0 : jpeg_write_m_byte (j_compress_ptr cinfo, int val)
239 : {
240 0 : (*cinfo->marker->write_marker_byte) (cinfo, val);
241 0 : }
242 :
243 :
244 : /*
245 : * Alternate compression function: just write an abbreviated table file.
246 : * Before calling this, all parameters and a data destination must be set up.
247 : *
248 : * To produce a pair of files containing abbreviated tables and abbreviated
249 : * image data, one would proceed as follows:
250 : *
251 : * initialize JPEG object
252 : * set JPEG parameters
253 : * set destination to table file
254 : * jpeg_write_tables(cinfo);
255 : * set destination to image file
256 : * jpeg_start_compress(cinfo, FALSE);
257 : * write data...
258 : * jpeg_finish_compress(cinfo);
259 : *
260 : * jpeg_write_tables has the side effect of marking all tables written
261 : * (same as jpeg_suppress_tables(..., TRUE)). Thus a subsequent start_compress
262 : * will not re-emit the tables unless it is passed write_all_tables=TRUE.
263 : */
264 :
265 : GLOBAL(void)
266 0 : jpeg_write_tables (j_compress_ptr cinfo)
267 : {
268 0 : if (cinfo->global_state != CSTATE_START)
269 0 : ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
270 :
271 : /* (Re)initialize error mgr and destination modules */
272 0 : (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
273 0 : (*cinfo->dest->init_destination) (cinfo);
274 : /* Initialize the marker writer ... bit of a crock to do it here. */
275 0 : jinit_marker_writer(cinfo);
276 : /* Write them tables! */
277 0 : (*cinfo->marker->write_tables_only) (cinfo);
278 : /* And clean up. */
279 0 : (*cinfo->dest->term_destination) (cinfo);
280 : /*
281 : * In library releases up through v6a, we called jpeg_abort() here to free
282 : * any working memory allocated by the destination manager and marker
283 : * writer. Some applications had a problem with that: they allocated space
284 : * of their own from the library memory manager, and didn't want it to go
285 : * away during write_tables. So now we do nothing. This will cause a
286 : * memory leak if an app calls write_tables repeatedly without doing a full
287 : * compression cycle or otherwise resetting the JPEG object. However, that
288 : * seems less bad than unexpectedly freeing memory in the normal case.
289 : * An app that prefers the old behavior can call jpeg_abort for itself after
290 : * each call to jpeg_write_tables().
291 : */
292 0 : }
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