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| 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 } |
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