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1 /* | |
2 * jcapimin.c | |
3 * | |
4 * Copyright (C) 1994-1998, Thomas G. Lane. | |
5 * This file is part of the Independent JPEG Group's software. | |
6 * For conditions of distribution and use, see the accompanying README file. | |
7 * | |
8 * This file contains application interface code for the compression half | |
9 * of the JPEG library. These are the "minimum" API routines that may be | |
10 * needed in either the normal full-compression case or the transcoding-only | |
11 * case. | |
12 * | |
13 * Most of the routines intended to be called directly by an application | |
14 * are in this file or in jcapistd.c. But also see jcparam.c for | |
15 * parameter-setup helper routines, jcomapi.c for routines shared by | |
16 * compression and decompression, and jctrans.c for the transcoding case. | |
17 */ | |
18 | |
19 #define JPEG_INTERNALS | |
20 #include "jinclude.h" | |
21 #include "jpeglib.h" | |
22 | |
23 | |
24 /* | |
25 * Initialization of a JPEG compression object. | |
26 * The error manager must already be set up (in case memory manager fails). | |
27 */ | |
28 | |
29 GLOBAL(void) | |
30 jpeg_CreateCompress (j_compress_ptr cinfo, int version, size_t structsize) | |
31 { | |
32 int i; | |
33 | |
34 /* Guard against version mismatches between library and caller. */ | |
35 cinfo->mem = NULL; /* so jpeg_destroy knows mem mgr not called */ | |
36 if (version != JPEG_LIB_VERSION) | |
37 ERREXIT2(cinfo, JERR_BAD_LIB_VERSION, JPEG_LIB_VERSION, version); | |
38 if (structsize != SIZEOF(struct jpeg_compress_struct)) | |
39 ERREXIT2(cinfo, JERR_BAD_STRUCT_SIZE, | |
40 (int) SIZEOF(struct jpeg_compress_struct), (int) structsize); | |
41 | |
42 /* For debugging purposes, we zero the whole master structure. | |
43 * But the application has already set the err pointer, and may have set | |
44 * client_data, so we have to save and restore those fields. | |
45 * Note: if application hasn't set client_data, tools like Purify may | |
46 * complain here. | |
47 */ | |
48 { | |
49 struct jpeg_error_mgr * err = cinfo->err; | |
50 void * client_data = cinfo->client_data; /* ignore Purify complaint here */ | |
51 MEMZERO(cinfo, SIZEOF(struct jpeg_compress_struct)); | |
52 cinfo->err = err; | |
53 cinfo->client_data = client_data; | |
54 } | |
55 cinfo->is_decompressor = FALSE; | |
56 | |
57 /* Initialize a memory manager instance for this object */ | |
58 jinit_memory_mgr((j_common_ptr) cinfo); | |
59 | |
60 /* Zero out pointers to permanent structures. */ | |
61 cinfo->progress = NULL; | |
62 cinfo->dest = NULL; | |
63 | |
64 cinfo->comp_info = NULL; | |
65 | |
66 for (i = 0; i < NUM_QUANT_TBLS; i++) | |
67 cinfo->quant_tbl_ptrs[i] = NULL; | |
68 | |
69 for (i = 0; i < NUM_HUFF_TBLS; i++) { | |
70 cinfo->dc_huff_tbl_ptrs[i] = NULL; | |
71 cinfo->ac_huff_tbl_ptrs[i] = NULL; | |
72 } | |
73 | |
74 cinfo->script_space = NULL; | |
75 | |
76 cinfo->input_gamma = 1.0; /* in case application forgets */ | |
77 | |
78 /* OK, I'm ready */ | |
79 cinfo->global_state = CSTATE_START; | |
80 } | |
81 | |
82 | |
83 /* | |
84 * Destruction of a JPEG compression object | |
85 */ | |
86 | |
87 GLOBAL(void) | |
88 jpeg_destroy_compress (j_compress_ptr cinfo) | |
89 { | |
90 jpeg_destroy((j_common_ptr) cinfo); /* use common routine */ | |
91 } | |
92 | |
93 | |
94 /* | |
95 * Abort processing of a JPEG compression operation, | |
96 * but don't destroy the object itself. | |
97 */ | |
98 | |
99 GLOBAL(void) | |
100 jpeg_abort_compress (j_compress_ptr cinfo) | |
101 { | |
102 jpeg_abort((j_common_ptr) cinfo); /* use common routine */ | |
103 } | |
104 | |
105 | |
106 /* | |
107 * Forcibly suppress or un-suppress all quantization and Huffman tables. | |
108 * Marks all currently defined tables as already written (if suppress) | |
109 * or not written (if !suppress). This will control whether they get emitted | |
110 * by a subsequent jpeg_start_compress call. | |
111 * | |
112 * This routine is exported for use by applications that want to produce | |
113 * abbreviated JPEG datastreams. It logically belongs in jcparam.c, but | |
114 * since it is called by jpeg_start_compress, we put it here --- otherwise | |
115 * jcparam.o would be linked whether the application used it or not. | |
116 */ | |
117 | |
118 GLOBAL(void) | |
119 jpeg_suppress_tables (j_compress_ptr cinfo, boolean suppress) | |
120 { | |
121 int i; | |
122 JQUANT_TBL * qtbl; | |
123 JHUFF_TBL * htbl; | |
124 | |
125 for (i = 0; i < NUM_QUANT_TBLS; i++) { | |
126 if ((qtbl = cinfo->quant_tbl_ptrs[i]) != NULL) | |
127 qtbl->sent_table = suppress; | |
128 } | |
129 | |
130 for (i = 0; i < NUM_HUFF_TBLS; i++) { | |
131 if ((htbl = cinfo->dc_huff_tbl_ptrs[i]) != NULL) | |
132 htbl->sent_table = suppress; | |
133 if ((htbl = cinfo->ac_huff_tbl_ptrs[i]) != NULL) | |
134 htbl->sent_table = suppress; | |
135 } | |
136 } | |
137 | |
138 | |
139 /* | |
140 * Finish JPEG compression. | |
141 * | |
142 * If a multipass operating mode was selected, this may do a great deal of | |
143 * work including most of the actual output. | |
144 */ | |
145 | |
146 GLOBAL(void) | |
147 jpeg_finish_compress (j_compress_ptr cinfo) | |
148 { | |
149 JDIMENSION iMCU_row; | |
150 | |
151 if (cinfo->global_state == CSTATE_SCANNING || | |
152 cinfo->global_state == CSTATE_RAW_OK) { | |
153 /* Terminate first pass */ | |
154 if (cinfo->next_scanline < cinfo->image_height) | |
155 ERREXIT(cinfo, JERR_TOO_LITTLE_DATA); | |
156 (*cinfo->master->finish_pass) (cinfo); | |
157 } else if (cinfo->global_state != CSTATE_WRCOEFS) | |
158 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); | |
159 /* Perform any remaining passes */ | |
160 while (! cinfo->master->is_last_pass) { | |
161 (*cinfo->master->prepare_for_pass) (cinfo); | |
162 for (iMCU_row = 0; iMCU_row < cinfo->total_iMCU_rows; iMCU_row++) { | |
163 if (cinfo->progress != NULL) { | |
164 cinfo->progress->pass_counter = (long) iMCU_row; | |
165 cinfo->progress->pass_limit = (long) cinfo->total_iMCU_rows; | |
166 (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo); | |
167 } | |
168 /* We bypass the main controller and invoke coef controller directly; | |
169 * all work is being done from the coefficient buffer. | |
170 */ | |
171 if (! (*cinfo->coef->compress_data) (cinfo, (JSAMPIMAGE) NULL)) | |
172 ERREXIT(cinfo, JERR_CANT_SUSPEND); | |
173 } | |
174 (*cinfo->master->finish_pass) (cinfo); | |
175 } | |
176 /* Write EOI, do final cleanup */ | |
177 (*cinfo->marker->write_file_trailer) (cinfo); | |
178 (*cinfo->dest->term_destination) (cinfo); | |
179 /* We can use jpeg_abort to release memory and reset global_state */ | |
180 jpeg_abort((j_common_ptr) cinfo); | |
181 } | |
182 | |
183 | |
184 /* | |
185 * Write a special marker. | |
186 * This is only recommended for writing COM or APPn markers. | |
187 * Must be called after jpeg_start_compress() and before | |
188 * first call to jpeg_write_scanlines() or jpeg_write_raw_data(). | |
189 */ | |
190 | |
191 GLOBAL(void) | |
192 jpeg_write_marker (j_compress_ptr cinfo, int marker, | |
193 const JOCTET *dataptr, unsigned int datalen) | |
194 { | |
195 JMETHOD(void, write_marker_byte, (j_compress_ptr info, int val)); | |
196 | |
197 if (cinfo->next_scanline != 0 || | |
198 (cinfo->global_state != CSTATE_SCANNING && | |
199 cinfo->global_state != CSTATE_RAW_OK && | |
200 cinfo->global_state != CSTATE_WRCOEFS)) | |
201 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); | |
202 | |
203 (*cinfo->marker->write_marker_header) (cinfo, marker, datalen); | |
204 write_marker_byte = cinfo->marker->write_marker_byte; /* copy for speed */ | |
205 while (datalen--) { | |
206 (*write_marker_byte) (cinfo, *dataptr); | |
207 dataptr++; | |
208 } | |
209 } | |
210 | |
211 /* Same, but piecemeal. */ | |
212 | |
213 GLOBAL(void) | |
214 jpeg_write_m_header (j_compress_ptr cinfo, int marker, unsigned int datalen) | |
215 { | |
216 if (cinfo->next_scanline != 0 || | |
217 (cinfo->global_state != CSTATE_SCANNING && | |
218 cinfo->global_state != CSTATE_RAW_OK && | |
219 cinfo->global_state != CSTATE_WRCOEFS)) | |
220 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); | |
221 | |
222 (*cinfo->marker->write_marker_header) (cinfo, marker, datalen); | |
223 } | |
224 | |
225 GLOBAL(void) | |
226 jpeg_write_m_byte (j_compress_ptr cinfo, int val) | |
227 { | |
228 (*cinfo->marker->write_marker_byte) (cinfo, val); | |
229 } | |
230 | |
231 | |
232 /* | |
233 * Alternate compression function: just write an abbreviated table file. | |
234 * Before calling this, all parameters and a data destination must be set up. | |
235 * | |
236 * To produce a pair of files containing abbreviated tables and abbreviated | |
237 * image data, one would proceed as follows: | |
238 * | |
239 * initialize JPEG object | |
240 * set JPEG parameters | |
241 * set destination to table file | |
242 * jpeg_write_tables(cinfo); | |
243 * set destination to image file | |
244 * jpeg_start_compress(cinfo, FALSE); | |
245 * write data... | |
246 * jpeg_finish_compress(cinfo); | |
247 * | |
248 * jpeg_write_tables has the side effect of marking all tables written | |
249 * (same as jpeg_suppress_tables(..., TRUE)). Thus a subsequent start_compress | |
250 * will not re-emit the tables unless it is passed write_all_tables=TRUE. | |
251 */ | |
252 | |
253 GLOBAL(void) | |
254 jpeg_write_tables (j_compress_ptr cinfo) | |
255 { | |
256 if (cinfo->global_state != CSTATE_START) | |
257 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); | |
258 | |
259 /* (Re)initialize error mgr and destination modules */ | |
260 (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo); | |
261 (*cinfo->dest->init_destination) (cinfo); | |
262 /* Initialize the marker writer ... bit of a crock to do it here. */ | |
263 jinit_marker_writer(cinfo); | |
264 /* Write them tables! */ | |
265 (*cinfo->marker->write_tables_only) (cinfo); | |
266 /* And clean up. */ | |
267 (*cinfo->dest->term_destination) (cinfo); | |
268 /* | |
269 * In library releases up through v6a, we called jpeg_abort() here to free | |
270 * any working memory allocated by the destination manager and marker | |
271 * writer. Some applications had a problem with that: they allocated space | |
272 * of their own from the library memory manager, and didn't want it to go | |
273 * away during write_tables. So now we do nothing. This will cause a | |
274 * memory leak if an app calls write_tables repeatedly without doing a full | |
275 * compression cycle or otherwise resetting the JPEG object. However, that | |
276 * seems less bad than unexpectedly freeing memory in the normal case. | |
277 * An app that prefers the old behavior can call jpeg_abort for itself after | |
278 * each call to jpeg_write_tables(). | |
279 */ | |
280 } | |
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