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 } 281
