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