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| 1 /* | |
| 2 * jdapistd.c | |
| 3 * | |
| 4 * Copyright (C) 1994-1996, 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 decompression half | |
| 9 * of the JPEG library. These are the "standard" API routines that are | |
| 10 * used in the normal full-decompression case. They are not used by a | |
| 11 * transcoding-only application. Note that if an application links in | |
| 12 * jpeg_start_decompress, it will end up linking in the entire decompressor. | |
| 13 * We thus must separate this file from jdapimin.c to avoid linking the | |
| 14 * whole decompression library into a transcoder. | |
| 15 */ | |
| 16 | |
| 17 #define JPEG_INTERNALS | |
| 18 #include "jinclude.h" | |
| 19 #include "jpeglib.h" | |
| 20 | |
| 21 | |
| 22 /* Forward declarations */ | |
| 23 LOCAL(boolean) output_pass_setup JPP((j_decompress_ptr cinfo)); | |
| 24 | |
| 25 | |
| 26 /* | |
| 27 * Decompression initialization. | |
| 28 * jpeg_read_header must be completed before calling this. | |
| 29 * | |
| 30 * If a multipass operating mode was selected, this will do all but the | |
| 31 * last pass, and thus may take a great deal of time. | |
| 32 * | |
| 33 * Returns FALSE if suspended. The return value need be inspected only if | |
| 34 * a suspending data source is used. | |
| 35 */ | |
| 36 | |
| 37 GLOBAL(boolean) | |
| 38 jpeg_start_decompress (j_decompress_ptr cinfo) | |
| 39 { | |
| 40 if (cinfo->global_state == DSTATE_READY) { | |
| 41 /* First call: initialize master control, select active modules */ | |
| 42 jinit_master_decompress(cinfo); | |
| 43 if (cinfo->buffered_image) { | |
| 44 /* No more work here; expecting jpeg_start_output next */ | |
| 45 cinfo->global_state = DSTATE_BUFIMAGE; | |
| 46 return TRUE; | |
| 47 } | |
| 48 cinfo->global_state = DSTATE_PRELOAD; | |
| 49 } | |
| 50 if (cinfo->global_state == DSTATE_PRELOAD) { | |
| 51 /* If file has multiple scans, absorb them all into the coef buffer */ | |
| 52 if (cinfo->inputctl->has_multiple_scans) { | |
| 53 #ifdef D_MULTISCAN_FILES_SUPPORTED | |
| 54 for (;;) { | |
| 55 int retcode; | |
| 56 /* Call progress monitor hook if present */ | |
| 57 if (cinfo->progress != NULL) | |
| 58 (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo); | |
| 59 /* Absorb some more input */ | |
| 60 retcode = (*cinfo->inputctl->consume_input) (cinfo); | |
| 61 if (retcode == JPEG_SUSPENDED) | |
| 62 return FALSE; | |
| 63 if (retcode == JPEG_REACHED_EOI) | |
| 64 break; | |
| 65 /* Advance progress counter if appropriate */ | |
| 66 if (cinfo->progress != NULL && | |
| 67 (retcode == JPEG_ROW_COMPLETED || retcode == JPEG_REACHED_SOS)) { | |
| 68 if (++cinfo->progress->pass_counter >= cinfo->progress->pass_limit) { | |
| 69 /* jdmaster underestimated number of scans; ratchet up one scan */ | |
| 70 cinfo->progress->pass_limit += (long) cinfo->total_iMCU_rows; | |
| 71 } | |
| 72 } | |
| 73 } | |
| 74 #else | |
| 75 ERREXIT(cinfo, JERR_NOT_COMPILED); | |
| 76 #endif /* D_MULTISCAN_FILES_SUPPORTED */ | |
| 77 } | |
| 78 cinfo->output_scan_number = cinfo->input_scan_number; | |
| 79 } else if (cinfo->global_state != DSTATE_PRESCAN) | |
| 80 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); | |
| 81 /* Perform any dummy output passes, and set up for the final pass */ | |
| 82 return output_pass_setup(cinfo); | |
| 83 } | |
| 84 | |
| 85 | |
| 86 /* | |
| 87 * Set up for an output pass, and perform any dummy pass(es) needed. | |
| 88 * Common subroutine for jpeg_start_decompress and jpeg_start_output. | |
| 89 * Entry: global_state = DSTATE_PRESCAN only if previously suspended. | |
| 90 * Exit: If done, returns TRUE and sets global_state for proper output mode. | |
| 91 * If suspended, returns FALSE and sets global_state = DSTATE_PRESCAN. | |
| 92 */ | |
| 93 | |
| 94 LOCAL(boolean) | |
| 95 output_pass_setup (j_decompress_ptr cinfo) | |
| 96 { | |
| 97 if (cinfo->global_state != DSTATE_PRESCAN) { | |
| 98 /* First call: do pass setup */ | |
| 99 (*cinfo->master->prepare_for_output_pass) (cinfo); | |
| 100 cinfo->output_scanline = 0; | |
| 101 cinfo->global_state = DSTATE_PRESCAN; | |
| 102 } | |
| 103 /* Loop over any required dummy passes */ | |
| 104 while (cinfo->master->is_dummy_pass) { | |
| 105 #ifdef QUANT_2PASS_SUPPORTED | |
| 106 /* Crank through the dummy pass */ | |
| 107 while (cinfo->output_scanline < cinfo->output_height) { | |
| 108 JDIMENSION last_scanline; | |
| 109 /* Call progress monitor hook if present */ | |
| 110 if (cinfo->progress != NULL) { | |
| 111 cinfo->progress->pass_counter = (long) cinfo->output_scanline; | |
| 112 cinfo->progress->pass_limit = (long) cinfo->output_height; | |
| 113 (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo); | |
| 114 } | |
| 115 /* Process some data */ | |
| 116 last_scanline = cinfo->output_scanline; | |
| 117 (*cinfo->main->process_data) (cinfo, (JSAMPARRAY) NULL, | |
| 118 &cinfo->output_scanline, (JDIMENSION) 0); | |
| 119 if (cinfo->output_scanline == last_scanline) | |
| 120 return FALSE; /* No progress made, must suspend */ | |
| 121 } | |
| 122 /* Finish up dummy pass, and set up for another one */ | |
| 123 (*cinfo->master->finish_output_pass) (cinfo); | |
| 124 (*cinfo->master->prepare_for_output_pass) (cinfo); | |
| 125 cinfo->output_scanline = 0; | |
| 126 #else | |
| 127 ERREXIT(cinfo, JERR_NOT_COMPILED); | |
| 128 #endif /* QUANT_2PASS_SUPPORTED */ | |
| 129 } | |
| 130 /* Ready for application to drive output pass through | |
| 131 * jpeg_read_scanlines or jpeg_read_raw_data. | |
| 132 */ | |
| 133 cinfo->global_state = cinfo->raw_data_out ? DSTATE_RAW_OK : DSTATE_SCANNING; | |
| 134 return TRUE; | |
| 135 } | |
| 136 | |
| 137 | |
| 138 /* | |
| 139 * Read some scanlines of data from the JPEG decompressor. | |
| 140 * | |
| 141 * The return value will be the number of lines actually read. | |
| 142 * This may be less than the number requested in several cases, | |
| 143 * including bottom of image, data source suspension, and operating | |
| 144 * modes that emit multiple scanlines at a time. | |
| 145 * | |
| 146 * Note: we warn about excess calls to jpeg_read_scanlines() since | |
| 147 * this likely signals an application programmer error. However, | |
| 148 * an oversize buffer (max_lines > scanlines remaining) is not an error. | |
| 149 */ | |
| 150 | |
| 151 GLOBAL(JDIMENSION) | |
| 152 jpeg_read_scanlines (j_decompress_ptr cinfo, JSAMPARRAY scanlines, | |
| 153 JDIMENSION max_lines) | |
| 154 { | |
| 155 JDIMENSION row_ctr; | |
| 156 | |
| 157 if (cinfo->global_state != DSTATE_SCANNING) | |
| 158 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); | |
| 159 if (cinfo->output_scanline >= cinfo->output_height) { | |
| 160 WARNMS(cinfo, JWRN_TOO_MUCH_DATA); | |
| 161 return 0; | |
| 162 } | |
| 163 | |
| 164 /* Call progress monitor hook if present */ | |
| 165 if (cinfo->progress != NULL) { | |
| 166 cinfo->progress->pass_counter = (long) cinfo->output_scanline; | |
| 167 cinfo->progress->pass_limit = (long) cinfo->output_height; | |
| 168 (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo); | |
| 169 } | |
| 170 | |
| 171 /* Process some data */ | |
| 172 row_ctr = 0; | |
| 173 (*cinfo->main->process_data) (cinfo, scanlines, &row_ctr, max_lines); | |
| 174 cinfo->output_scanline += row_ctr; | |
| 175 return row_ctr; | |
| 176 } | |
| 177 | |
| 178 | |
| 179 /* | |
| 180 * Alternate entry point to read raw data. | |
| 181 * Processes exactly one iMCU row per call, unless suspended. | |
| 182 */ | |
| 183 | |
| 184 GLOBAL(JDIMENSION) | |
| 185 jpeg_read_raw_data (j_decompress_ptr cinfo, JSAMPIMAGE data, | |
| 186 JDIMENSION max_lines) | |
| 187 { | |
| 188 JDIMENSION lines_per_iMCU_row; | |
| 189 | |
| 190 if (cinfo->global_state != DSTATE_RAW_OK) | |
| 191 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); | |
| 192 if (cinfo->output_scanline >= cinfo->output_height) { | |
| 193 WARNMS(cinfo, JWRN_TOO_MUCH_DATA); | |
| 194 return 0; | |
| 195 } | |
| 196 | |
| 197 /* Call progress monitor hook if present */ | |
| 198 if (cinfo->progress != NULL) { | |
| 199 cinfo->progress->pass_counter = (long) cinfo->output_scanline; | |
| 200 cinfo->progress->pass_limit = (long) cinfo->output_height; | |
| 201 (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo); | |
| 202 } | |
| 203 | |
| 204 /* Verify that at least one iMCU row can be returned. */ | |
| 205 lines_per_iMCU_row = cinfo->max_v_samp_factor * cinfo->min_DCT_scaled_size; | |
| 206 if (max_lines < lines_per_iMCU_row) | |
| 207 ERREXIT(cinfo, JERR_BUFFER_SIZE); | |
| 208 | |
| 209 /* Decompress directly into user's buffer. */ | |
| 210 if (! (*cinfo->coef->decompress_data) (cinfo, data)) | |
| 211 return 0; /* suspension forced, can do nothing more */ | |
| 212 | |
| 213 /* OK, we processed one iMCU row. */ | |
| 214 cinfo->output_scanline += lines_per_iMCU_row; | |
| 215 return lines_per_iMCU_row; | |
| 216 } | |
| 217 | |
| 218 | |
| 219 /* Additional entry points for buffered-image mode. */ | |
| 220 | |
| 221 #ifdef D_MULTISCAN_FILES_SUPPORTED | |
| 222 | |
| 223 /* | |
| 224 * Initialize for an output pass in buffered-image mode. | |
| 225 */ | |
| 226 | |
| 227 GLOBAL(boolean) | |
| 228 jpeg_start_output (j_decompress_ptr cinfo, int scan_number) | |
| 229 { | |
| 230 if (cinfo->global_state != DSTATE_BUFIMAGE && | |
| 231 cinfo->global_state != DSTATE_PRESCAN) | |
| 232 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); | |
| 233 /* Limit scan number to valid range */ | |
| 234 if (scan_number <= 0) | |
| 235 scan_number = 1; | |
| 236 if (cinfo->inputctl->eoi_reached && | |
| 237 scan_number > cinfo->input_scan_number) | |
| 238 scan_number = cinfo->input_scan_number; | |
| 239 cinfo->output_scan_number = scan_number; | |
| 240 /* Perform any dummy output passes, and set up for the real pass */ | |
| 241 return output_pass_setup(cinfo); | |
| 242 } | |
| 243 | |
| 244 | |
| 245 /* | |
| 246 * Finish up after an output pass in buffered-image mode. | |
| 247 * | |
| 248 * Returns FALSE if suspended. The return value need be inspected only if | |
| 249 * a suspending data source is used. | |
| 250 */ | |
| 251 | |
| 252 GLOBAL(boolean) | |
| 253 jpeg_finish_output (j_decompress_ptr cinfo) | |
| 254 { | |
| 255 if ((cinfo->global_state == DSTATE_SCANNING || | |
| 256 cinfo->global_state == DSTATE_RAW_OK) && cinfo->buffered_image) { | |
| 257 /* Terminate this pass. */ | |
| 258 /* We do not require the whole pass to have been completed. */ | |
| 259 (*cinfo->master->finish_output_pass) (cinfo); | |
| 260 cinfo->global_state = DSTATE_BUFPOST; | |
| 261 } else if (cinfo->global_state != DSTATE_BUFPOST) { | |
| 262 /* BUFPOST = repeat call after a suspension, anything else is error */ | |
| 263 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); | |
| 264 } | |
| 265 /* Read markers looking for SOS or EOI */ | |
| 266 while (cinfo->input_scan_number <= cinfo->output_scan_number && | |
| 267 ! cinfo->inputctl->eoi_reached) { | |
| 268 if ((*cinfo->inputctl->consume_input) (cinfo) == JPEG_SUSPENDED) | |
| 269 return FALSE; /* Suspend, come back later */ | |
| 270 } | |
| 271 cinfo->global_state = DSTATE_BUFIMAGE; | |
| 272 return TRUE; | |
| 273 } | |
| 274 | |
| 275 #endif /* D_MULTISCAN_FILES_SUPPORTED */ | |
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Chromium Code Reviews
Issue 1705523002:
Remove libjpeg and libjpeg_turbo. (Closed)
Base URL: https://github.com/domokit/mojo.git@master