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