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 #if JPEG_LIB_VERSION >= 70 70 cinfo->q_scale_factor[i] = 100; 71 #endif 72 } 73 74 for (i = 0; i < NUM_HUFF_TBLS; i++) { 75 cinfo->dc_huff_tbl_ptrs[i] = NULL; 76 cinfo->ac_huff_tbl_ptrs[i] = NULL; 77 } 78 79 #if JPEG_LIB_VERSION >= 80 80 /* Must do it here for emit_dqt in case jpeg_write_tables is used */ 81 cinfo->block_size = DCTSIZE; 82 cinfo->natural_order = jpeg_natural_order; 83 cinfo->lim_Se = DCTSIZE2-1; 84 #endif 85 86 cinfo->script_space = NULL; 87 88 cinfo->input_gamma = 1.0; /* in case application forgets */ 89 90 /* OK, I'm ready */ 91 cinfo->global_state = CSTATE_START; 92 } 93 94 95 /* 96 * Destruction of a JPEG compression object 97 */ 98 99 GLOBAL(void) 100 jpeg_destroy_compress (j_compress_ptr cinfo) 101 { 102 jpeg_destroy((j_common_ptr) cinfo); /* use common routine */ 103 } 104 105 106 /* 107 * Abort processing of a JPEG compression operation, 108 * but don't destroy the object itself. 109 */ 110 111 GLOBAL(void) 112 jpeg_abort_compress (j_compress_ptr cinfo) 113 { 114 jpeg_abort((j_common_ptr) cinfo); /* use common routine */ 115 } 116 117 118 /* 119 * Forcibly suppress or un-suppress all quantization and Huffman tables. 120 * Marks all currently defined tables as already written (if suppress) 121 * or not written (if !suppress). This will control whether they get emitted 122 * by a subsequent jpeg_start_compress call. 123 * 124 * This routine is exported for use by applications that want to produce 125 * abbreviated JPEG datastreams. It logically belongs in jcparam.c, but 126 * since it is called by jpeg_start_compress, we put it here --- otherwise 127 * jcparam.o would be linked whether the application used it or not. 128 */ 129 130 GLOBAL(void) 131 jpeg_suppress_tables (j_compress_ptr cinfo, boolean suppress) 132 { 133 int i; 134 JQUANT_TBL * qtbl; 135 JHUFF_TBL * htbl; 136 137 for (i = 0; i < NUM_QUANT_TBLS; i++) { 138 if ((qtbl = cinfo->quant_tbl_ptrs[i]) != NULL) 139 qtbl->sent_table = suppress; 140 } 141 142 for (i = 0; i < NUM_HUFF_TBLS; i++) { 143 if ((htbl = cinfo->dc_huff_tbl_ptrs[i]) != NULL) 144 htbl->sent_table = suppress; 145 if ((htbl = cinfo->ac_huff_tbl_ptrs[i]) != NULL) 146 htbl->sent_table = suppress; 147 } 148 } 149 150 151 /* 152 * Finish JPEG compression. 153 * 154 * If a multipass operating mode was selected, this may do a great deal of 155 * work including most of the actual output. 156 */ 157 158 GLOBAL(void) 159 jpeg_finish_compress (j_compress_ptr cinfo) 160 { 161 JDIMENSION iMCU_row; 162 163 if (cinfo->global_state == CSTATE_SCANNING || 164 cinfo->global_state == CSTATE_RAW_OK) { 165 /* Terminate first pass */ 166 if (cinfo->next_scanline < cinfo->image_height) 167 ERREXIT(cinfo, JERR_TOO_LITTLE_DATA); 168 (*cinfo->master->finish_pass) (cinfo); 169 } else if (cinfo->global_state != CSTATE_WRCOEFS) 170 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); 171 /* Perform any remaining passes */ 172 while (! cinfo->master->is_last_pass) { 173 (*cinfo->master->prepare_for_pass) (cinfo); 174 for (iMCU_row = 0; iMCU_row < cinfo->total_iMCU_rows; iMCU_row++) { 175 if (cinfo->progress != NULL) { 176 cinfo->progress->pass_counter = (long) iMCU_row; 177 cinfo->progress->pass_limit = (long) cinfo->total_iMCU_rows; 178 (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo); 179 } 180 /* We bypass the main controller and invoke coef controller directly; 181 * all work is being done from the coefficient buffer. 182 */ 183 if (! (*cinfo->coef->compress_data) (cinfo, (JSAMPIMAGE) NULL)) 184 ERREXIT(cinfo, JERR_CANT_SUSPEND); 185 } 186 (*cinfo->master->finish_pass) (cinfo); 187 } 188 /* Write EOI, do final cleanup */ 189 (*cinfo->marker->write_file_trailer) (cinfo); 190 (*cinfo->dest->term_destination) (cinfo); 191 /* We can use jpeg_abort to release memory and reset global_state */ 192 jpeg_abort((j_common_ptr) cinfo); 193 } 194 195 196 /* 197 * Write a special marker. 198 * This is only recommended for writing COM or APPn markers. 199 * Must be called after jpeg_start_compress() and before 200 * first call to jpeg_write_scanlines() or jpeg_write_raw_data(). 201 */ 202 203 GLOBAL(void) 204 jpeg_write_marker (j_compress_ptr cinfo, int marker, 205 const JOCTET *dataptr, unsigned int datalen) 206 { 207 JMETHOD(void, write_marker_byte, (j_compress_ptr info, int val)); 208 209 if (cinfo->next_scanline != 0 || 210 (cinfo->global_state != CSTATE_SCANNING && 211 cinfo->global_state != CSTATE_RAW_OK && 212 cinfo->global_state != CSTATE_WRCOEFS)) 213 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); 214 215 (*cinfo->marker->write_marker_header) (cinfo, marker, datalen); 216 write_marker_byte = cinfo->marker->write_marker_byte; /* copy for speed */ 217 while (datalen--) { 218 (*write_marker_byte) (cinfo, *dataptr); 219 dataptr++; 220 } 221 } 222 223 /* Same, but piecemeal. */ 224 225 GLOBAL(void) 226 jpeg_write_m_header (j_compress_ptr cinfo, int marker, unsigned int datalen) 227 { 228 if (cinfo->next_scanline != 0 || 229 (cinfo->global_state != CSTATE_SCANNING && 230 cinfo->global_state != CSTATE_RAW_OK && 231 cinfo->global_state != CSTATE_WRCOEFS)) 232 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); 233 234 (*cinfo->marker->write_marker_header) (cinfo, marker, datalen); 235 } 236 237 GLOBAL(void) 238 jpeg_write_m_byte (j_compress_ptr cinfo, int val) 239 { 240 (*cinfo->marker->write_marker_byte) (cinfo, val); 241 } 242 243 244 /* 245 * Alternate compression function: just write an abbreviated table file. 246 * Before calling this, all parameters and a data destination must be set up. 247 * 248 * To produce a pair of files containing abbreviated tables and abbreviated 249 * image data, one would proceed as follows: 250 * 251 * initialize JPEG object 252 * set JPEG parameters 253 * set destination to table file 254 * jpeg_write_tables(cinfo); 255 * set destination to image file 256 * jpeg_start_compress(cinfo, FALSE); 257 * write data... 258 * jpeg_finish_compress(cinfo); 259 * 260 * jpeg_write_tables has the side effect of marking all tables written 261 * (same as jpeg_suppress_tables(..., TRUE)). Thus a subsequent start_compress 262 * will not re-emit the tables unless it is passed write_all_tables=TRUE. 263 */ 264 265 GLOBAL(void) 266 jpeg_write_tables (j_compress_ptr cinfo) 267 { 268 if (cinfo->global_state != CSTATE_START) 269 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); 270 271 /* (Re)initialize error mgr and destination modules */ 272 (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo); 273 (*cinfo->dest->init_destination) (cinfo); 274 /* Initialize the marker writer ... bit of a crock to do it here. */ 275 jinit_marker_writer(cinfo); 276 /* Write them tables! */ 277 (*cinfo->marker->write_tables_only) (cinfo); 278 /* And clean up. */ 279 (*cinfo->dest->term_destination) (cinfo); 280 /* 281 * In library releases up through v6a, we called jpeg_abort() here to free 282 * any working memory allocated by the destination manager and marker 283 * writer. Some applications had a problem with that: they allocated space 284 * of their own from the library memory manager, and didn't want it to go 285 * away during write_tables. So now we do nothing. This will cause a 286 * memory leak if an app calls write_tables repeatedly without doing a full 287 * compression cycle or otherwise resetting the JPEG object. However, that 288 * seems less bad than unexpectedly freeing memory in the normal case. 289 * An app that prefers the old behavior can call jpeg_abort for itself after 290 * each call to jpeg_write_tables(). 291 */ 292 } 293
