]>
Commit | Line | Data |
---|---|---|
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 | } |