4 * This file was part of the Independent JPEG Group's software:
5 * Copyright (C) 1994-1998, Thomas G. Lane.
6 * Modified 2003-2010 by Guido Vollbeding.
7 * libjpeg-turbo Modifications:
8 * Copyright (C) 2022, D. R. Commander.
9 * For conditions of distribution and use, see the accompanying README.ijg
12 * This file contains application interface code for the compression half
13 * of the JPEG library. These are the "minimum" API routines that may be
14 * needed in either the normal full-compression case or the transcoding-only
17 * Most of the routines intended to be called directly by an application
18 * are in this file or in jcapistd.c. But also see jcparam.c for
19 * parameter-setup helper routines, jcomapi.c for routines shared by
20 * compression and decompression, and jctrans.c for the transcoding case.
23 #define JPEG_INTERNALS
30 * Initialization of a JPEG compression object.
31 * The error manager must already be set up (in case memory manager fails).
35 jpeg_CreateCompress(j_compress_ptr cinfo, int version, size_t structsize)
39 /* Guard against version mismatches between library and caller. */
40 cinfo->mem = NULL; /* so jpeg_destroy knows mem mgr not called */
41 if (version != JPEG_LIB_VERSION)
42 ERREXIT2(cinfo, JERR_BAD_LIB_VERSION, JPEG_LIB_VERSION, version);
43 if (structsize != sizeof(struct jpeg_compress_struct))
44 ERREXIT2(cinfo, JERR_BAD_STRUCT_SIZE,
45 (int)sizeof(struct jpeg_compress_struct), (int)structsize);
47 /* For debugging purposes, we zero the whole master structure.
48 * But the application has already set the err pointer, and may have set
49 * client_data, so we have to save and restore those fields.
50 * Note: if application hasn't set client_data, tools like Purify may
54 struct jpeg_error_mgr *err = cinfo->err;
55 void *client_data = cinfo->client_data; /* ignore Purify complaint here */
56 memset(cinfo, 0, sizeof(struct jpeg_compress_struct));
58 cinfo->client_data = client_data;
60 cinfo->is_decompressor = FALSE;
62 /* Initialize a memory manager instance for this object */
63 jinit_memory_mgr((j_common_ptr)cinfo);
65 /* Zero out pointers to permanent structures. */
66 cinfo->progress = NULL;
69 cinfo->comp_info = NULL;
71 for (i = 0; i < NUM_QUANT_TBLS; i++) {
72 cinfo->quant_tbl_ptrs[i] = NULL;
73 #if JPEG_LIB_VERSION >= 70
74 cinfo->q_scale_factor[i] = 100;
78 for (i = 0; i < NUM_HUFF_TBLS; i++) {
79 cinfo->dc_huff_tbl_ptrs[i] = NULL;
80 cinfo->ac_huff_tbl_ptrs[i] = NULL;
83 #if JPEG_LIB_VERSION >= 80
84 /* Must do it here for emit_dqt in case jpeg_write_tables is used */
85 cinfo->block_size = DCTSIZE;
86 cinfo->natural_order = jpeg_natural_order;
87 cinfo->lim_Se = DCTSIZE2 - 1;
90 cinfo->script_space = NULL;
92 cinfo->input_gamma = 1.0; /* in case application forgets */
94 cinfo->data_precision = BITS_IN_JSAMPLE;
97 cinfo->global_state = CSTATE_START;
99 /* The master struct is used to store extension parameters, so we allocate it
102 cinfo->master = (struct jpeg_comp_master *)
103 (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_PERMANENT,
104 sizeof(my_comp_master));
105 memset(cinfo->master, 0, sizeof(my_comp_master));
110 * Destruction of a JPEG compression object
114 jpeg_destroy_compress(j_compress_ptr cinfo)
116 jpeg_destroy((j_common_ptr)cinfo); /* use common routine */
121 * Abort processing of a JPEG compression operation,
122 * but don't destroy the object itself.
126 jpeg_abort_compress(j_compress_ptr cinfo)
128 jpeg_abort((j_common_ptr)cinfo); /* use common routine */
133 * Forcibly suppress or un-suppress all quantization and Huffman tables.
134 * Marks all currently defined tables as already written (if suppress)
135 * or not written (if !suppress). This will control whether they get emitted
136 * by a subsequent jpeg_start_compress call.
138 * This routine is exported for use by applications that want to produce
139 * abbreviated JPEG datastreams. It logically belongs in jcparam.c, but
140 * since it is called by jpeg_start_compress, we put it here --- otherwise
141 * jcparam.o would be linked whether the application used it or not.
145 jpeg_suppress_tables(j_compress_ptr cinfo, boolean suppress)
151 for (i = 0; i < NUM_QUANT_TBLS; i++) {
152 if ((qtbl = cinfo->quant_tbl_ptrs[i]) != NULL)
153 qtbl->sent_table = suppress;
156 for (i = 0; i < NUM_HUFF_TBLS; i++) {
157 if ((htbl = cinfo->dc_huff_tbl_ptrs[i]) != NULL)
158 htbl->sent_table = suppress;
159 if ((htbl = cinfo->ac_huff_tbl_ptrs[i]) != NULL)
160 htbl->sent_table = suppress;
166 * Finish JPEG compression.
168 * If a multipass operating mode was selected, this may do a great deal of
169 * work including most of the actual output.
173 jpeg_finish_compress(j_compress_ptr cinfo)
177 if (cinfo->global_state == CSTATE_SCANNING ||
178 cinfo->global_state == CSTATE_RAW_OK) {
179 /* Terminate first pass */
180 if (cinfo->next_scanline < cinfo->image_height)
181 ERREXIT(cinfo, JERR_TOO_LITTLE_DATA);
182 (*cinfo->master->finish_pass) (cinfo);
183 } else if (cinfo->global_state != CSTATE_WRCOEFS)
184 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
185 /* Perform any remaining passes */
186 while (!cinfo->master->is_last_pass) {
187 (*cinfo->master->prepare_for_pass) (cinfo);
188 for (iMCU_row = 0; iMCU_row < cinfo->total_iMCU_rows; iMCU_row++) {
189 if (cinfo->progress != NULL) {
190 cinfo->progress->pass_counter = (long)iMCU_row;
191 cinfo->progress->pass_limit = (long)cinfo->total_iMCU_rows;
192 (*cinfo->progress->progress_monitor) ((j_common_ptr)cinfo);
194 /* We bypass the main controller and invoke coef controller directly;
195 * all work is being done from the coefficient buffer.
197 if (cinfo->data_precision == 16) {
198 #ifdef C_LOSSLESS_SUPPORTED
199 if (!(*cinfo->coef->compress_data_16) (cinfo, (J16SAMPIMAGE)NULL))
200 ERREXIT(cinfo, JERR_CANT_SUSPEND);
202 ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision);
204 } else if (cinfo->data_precision == 12) {
205 if (!(*cinfo->coef->compress_data_12) (cinfo, (J12SAMPIMAGE)NULL))
206 ERREXIT(cinfo, JERR_CANT_SUSPEND);
208 if (!(*cinfo->coef->compress_data) (cinfo, (JSAMPIMAGE)NULL))
209 ERREXIT(cinfo, JERR_CANT_SUSPEND);
212 (*cinfo->master->finish_pass) (cinfo);
214 /* Write EOI, do final cleanup */
215 (*cinfo->marker->write_file_trailer) (cinfo);
216 (*cinfo->dest->term_destination) (cinfo);
217 /* We can use jpeg_abort to release memory and reset global_state */
218 jpeg_abort((j_common_ptr)cinfo);
223 * Write a special marker.
224 * This is only recommended for writing COM or APPn markers.
225 * Must be called after jpeg_start_compress() and before
226 * first call to jpeg_write_scanlines() or jpeg_write_raw_data().
230 jpeg_write_marker(j_compress_ptr cinfo, int marker, const JOCTET *dataptr,
231 unsigned int datalen)
233 void (*write_marker_byte) (j_compress_ptr info, int val);
235 if (cinfo->next_scanline != 0 ||
236 (cinfo->global_state != CSTATE_SCANNING &&
237 cinfo->global_state != CSTATE_RAW_OK &&
238 cinfo->global_state != CSTATE_WRCOEFS))
239 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
241 (*cinfo->marker->write_marker_header) (cinfo, marker, datalen);
242 write_marker_byte = cinfo->marker->write_marker_byte; /* copy for speed */
244 (*write_marker_byte) (cinfo, *dataptr);
249 /* Same, but piecemeal. */
252 jpeg_write_m_header(j_compress_ptr cinfo, int marker, unsigned int datalen)
254 if (cinfo->next_scanline != 0 ||
255 (cinfo->global_state != CSTATE_SCANNING &&
256 cinfo->global_state != CSTATE_RAW_OK &&
257 cinfo->global_state != CSTATE_WRCOEFS))
258 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
260 (*cinfo->marker->write_marker_header) (cinfo, marker, datalen);
264 jpeg_write_m_byte(j_compress_ptr cinfo, int val)
266 (*cinfo->marker->write_marker_byte) (cinfo, val);
271 * Alternate compression function: just write an abbreviated table file.
272 * Before calling this, all parameters and a data destination must be set up.
274 * To produce a pair of files containing abbreviated tables and abbreviated
275 * image data, one would proceed as follows:
277 * initialize JPEG object
278 * set JPEG parameters
279 * set destination to table file
280 * jpeg_write_tables(cinfo);
281 * set destination to image file
282 * jpeg_start_compress(cinfo, FALSE);
284 * jpeg_finish_compress(cinfo);
286 * jpeg_write_tables has the side effect of marking all tables written
287 * (same as jpeg_suppress_tables(..., TRUE)). Thus a subsequent start_compress
288 * will not re-emit the tables unless it is passed write_all_tables=TRUE.
292 jpeg_write_tables(j_compress_ptr cinfo)
294 if (cinfo->global_state != CSTATE_START)
295 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
297 /* (Re)initialize error mgr and destination modules */
298 (*cinfo->err->reset_error_mgr) ((j_common_ptr)cinfo);
299 (*cinfo->dest->init_destination) (cinfo);
300 /* Initialize the marker writer ... bit of a crock to do it here. */
301 jinit_marker_writer(cinfo);
302 /* Write them tables! */
303 (*cinfo->marker->write_tables_only) (cinfo);
305 (*cinfo->dest->term_destination) (cinfo);
307 * In library releases up through v6a, we called jpeg_abort() here to free
308 * any working memory allocated by the destination manager and marker
309 * writer. Some applications had a problem with that: they allocated space
310 * of their own from the library memory manager, and didn't want it to go
311 * away during write_tables. So now we do nothing. This will cause a
312 * memory leak if an app calls write_tables repeatedly without doing a full
313 * compression cycle or otherwise resetting the JPEG object. However, that
314 * seems less bad than unexpectedly freeing memory in the normal case.
315 * An app that prefers the old behavior can call jpeg_abort for itself after
316 * each call to jpeg_write_tables().