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
29GLOBAL(void)
30jpeg_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
87GLOBAL(void)
88jpeg_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
99GLOBAL(void)
100jpeg_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
118GLOBAL(void)
119jpeg_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
146GLOBAL(void)
147jpeg_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
191GLOBAL(void)
192jpeg_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
213GLOBAL(void)
214jpeg_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
225GLOBAL(void)
226jpeg_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
253GLOBAL(void)
254jpeg_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}
281