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| 1 /* | |
| 2 * jcmarker.c | |
| 3 * | |
| 4 * Copyright (C) 1991-1998, 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 routines to write JPEG datastream markers. | |
| 9 */ | |
| 10 | |
| 11 #define JPEG_INTERNALS | |
| 12 #include "jinclude.h" | |
| 13 #include "jpeglib.h" | |
| 14 | |
| 15 | |
| 16 typedef enum { /* JPEG marker codes */ | |
| 17 M_SOF0 = 0xc0, | |
| 18 M_SOF1 = 0xc1, | |
| 19 M_SOF2 = 0xc2, | |
| 20 M_SOF3 = 0xc3, | |
| 21 | |
| 22 M_SOF5 = 0xc5, | |
| 23 M_SOF6 = 0xc6, | |
| 24 M_SOF7 = 0xc7, | |
| 25 | |
| 26 M_JPG = 0xc8, | |
| 27 M_SOF9 = 0xc9, | |
| 28 M_SOF10 = 0xca, | |
| 29 M_SOF11 = 0xcb, | |
| 30 | |
| 31 M_SOF13 = 0xcd, | |
| 32 M_SOF14 = 0xce, | |
| 33 M_SOF15 = 0xcf, | |
| 34 | |
| 35 M_DHT = 0xc4, | |
| 36 | |
| 37 M_DAC = 0xcc, | |
| 38 | |
| 39 M_RST0 = 0xd0, | |
| 40 M_RST1 = 0xd1, | |
| 41 M_RST2 = 0xd2, | |
| 42 M_RST3 = 0xd3, | |
| 43 M_RST4 = 0xd4, | |
| 44 M_RST5 = 0xd5, | |
| 45 M_RST6 = 0xd6, | |
| 46 M_RST7 = 0xd7, | |
| 47 | |
| 48 M_SOI = 0xd8, | |
| 49 M_EOI = 0xd9, | |
| 50 M_SOS = 0xda, | |
| 51 M_DQT = 0xdb, | |
| 52 M_DNL = 0xdc, | |
| 53 M_DRI = 0xdd, | |
| 54 M_DHP = 0xde, | |
| 55 M_EXP = 0xdf, | |
| 56 | |
| 57 M_APP0 = 0xe0, | |
| 58 M_APP1 = 0xe1, | |
| 59 M_APP2 = 0xe2, | |
| 60 M_APP3 = 0xe3, | |
| 61 M_APP4 = 0xe4, | |
| 62 M_APP5 = 0xe5, | |
| 63 M_APP6 = 0xe6, | |
| 64 M_APP7 = 0xe7, | |
| 65 M_APP8 = 0xe8, | |
| 66 M_APP9 = 0xe9, | |
| 67 M_APP10 = 0xea, | |
| 68 M_APP11 = 0xeb, | |
| 69 M_APP12 = 0xec, | |
| 70 M_APP13 = 0xed, | |
| 71 M_APP14 = 0xee, | |
| 72 M_APP15 = 0xef, | |
| 73 | |
| 74 M_JPG0 = 0xf0, | |
| 75 M_JPG13 = 0xfd, | |
| 76 M_COM = 0xfe, | |
| 77 | |
| 78 M_TEM = 0x01, | |
| 79 | |
| 80 M_ERROR = 0x100 | |
| 81 } JPEG_MARKER; | |
| 82 | |
| 83 | |
| 84 /* Private state */ | |
| 85 | |
| 86 typedef struct { | |
| 87 struct jpeg_marker_writer pub; /* public fields */ | |
| 88 | |
| 89 unsigned int last_restart_interval; /* last DRI value emitted; 0 after SOI */ | |
| 90 } my_marker_writer; | |
| 91 | |
| 92 typedef my_marker_writer * my_marker_ptr; | |
| 93 | |
| 94 | |
| 95 /* | |
| 96 * Basic output routines. | |
| 97 * | |
| 98 * Note that we do not support suspension while writing a marker. | |
| 99 * Therefore, an application using suspension must ensure that there is | |
| 100 * enough buffer space for the initial markers (typ. 600-700 bytes) before | |
| 101 * calling jpeg_start_compress, and enough space to write the trailing EOI | |
| 102 * (a few bytes) before calling jpeg_finish_compress. Multipass compression | |
| 103 * modes are not supported at all with suspension, so those two are the only | |
| 104 * points where markers will be written. | |
| 105 */ | |
| 106 | |
| 107 LOCAL(void) | |
| 108 emit_byte (j_compress_ptr cinfo, int val) | |
| 109 /* Emit a byte */ | |
| 110 { | |
| 111 struct jpeg_destination_mgr * dest = cinfo->dest; | |
| 112 | |
| 113 *(dest->next_output_byte)++ = (JOCTET) val; | |
| 114 if (--dest->free_in_buffer == 0) { | |
| 115 if (! (*dest->empty_output_buffer) (cinfo)) | |
| 116 ERREXIT(cinfo, JERR_CANT_SUSPEND); | |
| 117 } | |
| 118 } | |
| 119 | |
| 120 | |
| 121 LOCAL(void) | |
| 122 emit_marker (j_compress_ptr cinfo, JPEG_MARKER mark) | |
| 123 /* Emit a marker code */ | |
| 124 { | |
| 125 emit_byte(cinfo, 0xFF); | |
| 126 emit_byte(cinfo, (int) mark); | |
| 127 } | |
| 128 | |
| 129 | |
| 130 LOCAL(void) | |
| 131 emit_2bytes (j_compress_ptr cinfo, int value) | |
| 132 /* Emit a 2-byte integer; these are always MSB first in JPEG files */ | |
| 133 { | |
| 134 emit_byte(cinfo, (value >> 8) & 0xFF); | |
| 135 emit_byte(cinfo, value & 0xFF); | |
| 136 } | |
| 137 | |
| 138 | |
| 139 /* | |
| 140 * Routines to write specific marker types. | |
| 141 */ | |
| 142 | |
| 143 LOCAL(int) | |
| 144 emit_dqt (j_compress_ptr cinfo, int index) | |
| 145 /* Emit a DQT marker */ | |
| 146 /* Returns the precision used (0 = 8bits, 1 = 16bits) for baseline checking */ | |
| 147 { | |
| 148 JQUANT_TBL * qtbl = cinfo->quant_tbl_ptrs[index]; | |
| 149 int prec; | |
| 150 int i; | |
| 151 | |
| 152 if (qtbl == NULL) | |
| 153 ERREXIT1(cinfo, JERR_NO_QUANT_TABLE, index); | |
| 154 | |
| 155 prec = 0; | |
| 156 for (i = 0; i < DCTSIZE2; i++) { | |
| 157 if (qtbl->quantval[i] > 255) | |
| 158 prec = 1; | |
| 159 } | |
| 160 | |
| 161 if (! qtbl->sent_table) { | |
| 162 emit_marker(cinfo, M_DQT); | |
| 163 | |
| 164 emit_2bytes(cinfo, prec ? DCTSIZE2*2 + 1 + 2 : DCTSIZE2 + 1 + 2); | |
| 165 | |
| 166 emit_byte(cinfo, index + (prec<<4)); | |
| 167 | |
| 168 for (i = 0; i < DCTSIZE2; i++) { | |
| 169 /* The table entries must be emitted in zigzag order. */ | |
| 170 unsigned int qval = qtbl->quantval[jpeg_natural_order[i]]; | |
| 171 if (prec) | |
| 172 emit_byte(cinfo, (int) (qval >> 8)); | |
| 173 emit_byte(cinfo, (int) (qval & 0xFF)); | |
| 174 } | |
| 175 | |
| 176 qtbl->sent_table = TRUE; | |
| 177 } | |
| 178 | |
| 179 return prec; | |
| 180 } | |
| 181 | |
| 182 | |
| 183 LOCAL(void) | |
| 184 emit_dht (j_compress_ptr cinfo, int index, boolean is_ac) | |
| 185 /* Emit a DHT marker */ | |
| 186 { | |
| 187 JHUFF_TBL * htbl; | |
| 188 int length, i; | |
| 189 | |
| 190 if (is_ac) { | |
| 191 htbl = cinfo->ac_huff_tbl_ptrs[index]; | |
| 192 index += 0x10; /* output index has AC bit set */ | |
| 193 } else { | |
| 194 htbl = cinfo->dc_huff_tbl_ptrs[index]; | |
| 195 } | |
| 196 | |
| 197 if (htbl == NULL) | |
| 198 ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, index); | |
| 199 | |
| 200 if (! htbl->sent_table) { | |
| 201 emit_marker(cinfo, M_DHT); | |
| 202 | |
| 203 length = 0; | |
| 204 for (i = 1; i <= 16; i++) | |
| 205 length += htbl->bits[i]; | |
| 206 | |
| 207 emit_2bytes(cinfo, length + 2 + 1 + 16); | |
| 208 emit_byte(cinfo, index); | |
| 209 | |
| 210 for (i = 1; i <= 16; i++) | |
| 211 emit_byte(cinfo, htbl->bits[i]); | |
| 212 | |
| 213 for (i = 0; i < length; i++) | |
| 214 emit_byte(cinfo, htbl->huffval[i]); | |
| 215 | |
| 216 htbl->sent_table = TRUE; | |
| 217 } | |
| 218 } | |
| 219 | |
| 220 | |
| 221 LOCAL(void) | |
| 222 emit_dac (j_compress_ptr cinfo) | |
| 223 /* Emit a DAC marker */ | |
| 224 /* Since the useful info is so small, we want to emit all the tables in */ | |
| 225 /* one DAC marker. Therefore this routine does its own scan of the table. */ | |
| 226 { | |
| 227 #ifdef C_ARITH_CODING_SUPPORTED | |
| 228 char dc_in_use[NUM_ARITH_TBLS]; | |
| 229 char ac_in_use[NUM_ARITH_TBLS]; | |
| 230 int length, i; | |
| 231 jpeg_component_info *compptr; | |
| 232 | |
| 233 for (i = 0; i < NUM_ARITH_TBLS; i++) | |
| 234 dc_in_use[i] = ac_in_use[i] = 0; | |
| 235 | |
| 236 for (i = 0; i < cinfo->comps_in_scan; i++) { | |
| 237 compptr = cinfo->cur_comp_info[i]; | |
| 238 dc_in_use[compptr->dc_tbl_no] = 1; | |
| 239 ac_in_use[compptr->ac_tbl_no] = 1; | |
| 240 } | |
| 241 | |
| 242 length = 0; | |
| 243 for (i = 0; i < NUM_ARITH_TBLS; i++) | |
| 244 length += dc_in_use[i] + ac_in_use[i]; | |
| 245 | |
| 246 emit_marker(cinfo, M_DAC); | |
| 247 | |
| 248 emit_2bytes(cinfo, length*2 + 2); | |
| 249 | |
| 250 for (i = 0; i < NUM_ARITH_TBLS; i++) { | |
| 251 if (dc_in_use[i]) { | |
| 252 emit_byte(cinfo, i); | |
| 253 emit_byte(cinfo, cinfo->arith_dc_L[i] + (cinfo->arith_dc_U[i]<<4)); | |
| 254 } | |
| 255 if (ac_in_use[i]) { | |
| 256 emit_byte(cinfo, i + 0x10); | |
| 257 emit_byte(cinfo, cinfo->arith_ac_K[i]); | |
| 258 } | |
| 259 } | |
| 260 #endif /* C_ARITH_CODING_SUPPORTED */ | |
| 261 } | |
| 262 | |
| 263 | |
| 264 LOCAL(void) | |
| 265 emit_dri (j_compress_ptr cinfo) | |
| 266 /* Emit a DRI marker */ | |
| 267 { | |
| 268 emit_marker(cinfo, M_DRI); | |
| 269 | |
| 270 emit_2bytes(cinfo, 4); /* fixed length */ | |
| 271 | |
| 272 emit_2bytes(cinfo, (int) cinfo->restart_interval); | |
| 273 } | |
| 274 | |
| 275 | |
| 276 LOCAL(void) | |
| 277 emit_sof (j_compress_ptr cinfo, JPEG_MARKER code) | |
| 278 /* Emit a SOF marker */ | |
| 279 { | |
| 280 int ci; | |
| 281 jpeg_component_info *compptr; | |
| 282 | |
| 283 emit_marker(cinfo, code); | |
| 284 | |
| 285 emit_2bytes(cinfo, 3 * cinfo->num_components + 2 + 5 + 1); /* length */ | |
| 286 | |
| 287 /* Make sure image isn't bigger than SOF field can handle */ | |
| 288 if ((long) cinfo->image_height > 65535L || | |
| 289 (long) cinfo->image_width > 65535L) | |
| 290 ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) 65535); | |
| 291 | |
| 292 emit_byte(cinfo, cinfo->data_precision); | |
| 293 emit_2bytes(cinfo, (int) cinfo->image_height); | |
| 294 emit_2bytes(cinfo, (int) cinfo->image_width); | |
| 295 | |
| 296 emit_byte(cinfo, cinfo->num_components); | |
| 297 | |
| 298 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; | |
| 299 ci++, compptr++) { | |
| 300 emit_byte(cinfo, compptr->component_id); | |
| 301 emit_byte(cinfo, (compptr->h_samp_factor << 4) + compptr->v_samp_factor); | |
| 302 emit_byte(cinfo, compptr->quant_tbl_no); | |
| 303 } | |
| 304 } | |
| 305 | |
| 306 | |
| 307 LOCAL(void) | |
| 308 emit_sos (j_compress_ptr cinfo) | |
| 309 /* Emit a SOS marker */ | |
| 310 { | |
| 311 int i, td, ta; | |
| 312 jpeg_component_info *compptr; | |
| 313 | |
| 314 emit_marker(cinfo, M_SOS); | |
| 315 | |
| 316 emit_2bytes(cinfo, 2 * cinfo->comps_in_scan + 2 + 1 + 3); /* length */ | |
| 317 | |
| 318 emit_byte(cinfo, cinfo->comps_in_scan); | |
| 319 | |
| 320 for (i = 0; i < cinfo->comps_in_scan; i++) { | |
| 321 compptr = cinfo->cur_comp_info[i]; | |
| 322 emit_byte(cinfo, compptr->component_id); | |
| 323 td = compptr->dc_tbl_no; | |
| 324 ta = compptr->ac_tbl_no; | |
| 325 if (cinfo->progressive_mode) { | |
| 326 /* Progressive mode: only DC or only AC tables are used in one scan; | |
| 327 * furthermore, Huffman coding of DC refinement uses no table at all. | |
| 328 * We emit 0 for unused field(s); this is recommended by the P&M text | |
| 329 * but does not seem to be specified in the standard. | |
| 330 */ | |
| 331 if (cinfo->Ss == 0) { | |
| 332 ta = 0; /* DC scan */ | |
| 333 if (cinfo->Ah != 0 && !cinfo->arith_code) | |
| 334 td = 0; /* no DC table either */ | |
| 335 } else { | |
| 336 td = 0; /* AC scan */ | |
| 337 } | |
| 338 } | |
| 339 emit_byte(cinfo, (td << 4) + ta); | |
| 340 } | |
| 341 | |
| 342 emit_byte(cinfo, cinfo->Ss); | |
| 343 emit_byte(cinfo, cinfo->Se); | |
| 344 emit_byte(cinfo, (cinfo->Ah << 4) + cinfo->Al); | |
| 345 } | |
| 346 | |
| 347 | |
| 348 LOCAL(void) | |
| 349 emit_jfif_app0 (j_compress_ptr cinfo) | |
| 350 /* Emit a JFIF-compliant APP0 marker */ | |
| 351 { | |
| 352 /* | |
| 353 * Length of APP0 block (2 bytes) | |
| 354 * Block ID (4 bytes - ASCII "JFIF") | |
| 355 * Zero byte (1 byte to terminate the ID string) | |
| 356 * Version Major, Minor (2 bytes - major first) | |
| 357 * Units (1 byte - 0x00 = none, 0x01 = inch, 0x02 = cm) | |
| 358 * Xdpu (2 bytes - dots per unit horizontal) | |
| 359 * Ydpu (2 bytes - dots per unit vertical) | |
| 360 * Thumbnail X size (1 byte) | |
| 361 * Thumbnail Y size (1 byte) | |
| 362 */ | |
| 363 | |
| 364 emit_marker(cinfo, M_APP0); | |
| 365 | |
| 366 emit_2bytes(cinfo, 2 + 4 + 1 + 2 + 1 + 2 + 2 + 1 + 1); /* length */ | |
| 367 | |
| 368 emit_byte(cinfo, 0x4A); /* Identifier: ASCII "JFIF" */ | |
| 369 emit_byte(cinfo, 0x46); | |
| 370 emit_byte(cinfo, 0x49); | |
| 371 emit_byte(cinfo, 0x46); | |
| 372 emit_byte(cinfo, 0); | |
| 373 emit_byte(cinfo, cinfo->JFIF_major_version); /* Version fields */ | |
| 374 emit_byte(cinfo, cinfo->JFIF_minor_version); | |
| 375 emit_byte(cinfo, cinfo->density_unit); /* Pixel size information */ | |
| 376 emit_2bytes(cinfo, (int) cinfo->X_density); | |
| 377 emit_2bytes(cinfo, (int) cinfo->Y_density); | |
| 378 emit_byte(cinfo, 0); /* No thumbnail image */ | |
| 379 emit_byte(cinfo, 0); | |
| 380 } | |
| 381 | |
| 382 | |
| 383 LOCAL(void) | |
| 384 emit_adobe_app14 (j_compress_ptr cinfo) | |
| 385 /* Emit an Adobe APP14 marker */ | |
| 386 { | |
| 387 /* | |
| 388 * Length of APP14 block (2 bytes) | |
| 389 * Block ID (5 bytes - ASCII "Adobe") | |
| 390 * Version Number (2 bytes - currently 100) | |
| 391 * Flags0 (2 bytes - currently 0) | |
| 392 * Flags1 (2 bytes - currently 0) | |
| 393 * Color transform (1 byte) | |
| 394 * | |
| 395 * Although Adobe TN 5116 mentions Version = 101, all the Adobe files | |
| 396 * now in circulation seem to use Version = 100, so that's what we write. | |
| 397 * | |
| 398 * We write the color transform byte as 1 if the JPEG color space is | |
| 399 * YCbCr, 2 if it's YCCK, 0 otherwise. Adobe's definition has to do with | |
| 400 * whether the encoder performed a transformation, which is pretty useless. | |
| 401 */ | |
| 402 | |
| 403 emit_marker(cinfo, M_APP14); | |
| 404 | |
| 405 emit_2bytes(cinfo, 2 + 5 + 2 + 2 + 2 + 1); /* length */ | |
| 406 | |
| 407 emit_byte(cinfo, 0x41); /* Identifier: ASCII "Adobe" */ | |
| 408 emit_byte(cinfo, 0x64); | |
| 409 emit_byte(cinfo, 0x6F); | |
| 410 emit_byte(cinfo, 0x62); | |
| 411 emit_byte(cinfo, 0x65); | |
| 412 emit_2bytes(cinfo, 100); /* Version */ | |
| 413 emit_2bytes(cinfo, 0); /* Flags0 */ | |
| 414 emit_2bytes(cinfo, 0); /* Flags1 */ | |
| 415 switch (cinfo->jpeg_color_space) { | |
| 416 case JCS_YCbCr: | |
| 417 emit_byte(cinfo, 1); /* Color transform = 1 */ | |
| 418 break; | |
| 419 case JCS_YCCK: | |
| 420 emit_byte(cinfo, 2); /* Color transform = 2 */ | |
| 421 break; | |
| 422 default: | |
| 423 emit_byte(cinfo, 0); /* Color transform = 0 */ | |
| 424 break; | |
| 425 } | |
| 426 } | |
| 427 | |
| 428 | |
| 429 /* | |
| 430 * These routines allow writing an arbitrary marker with parameters. | |
| 431 * The only intended use is to emit COM or APPn markers after calling | |
| 432 * write_file_header and before calling write_frame_header. | |
| 433 * Other uses are not guaranteed to produce desirable results. | |
| 434 * Counting the parameter bytes properly is the caller's responsibility. | |
| 435 */ | |
| 436 | |
| 437 METHODDEF(void) | |
| 438 write_marker_header (j_compress_ptr cinfo, int marker, unsigned int datalen) | |
| 439 /* Emit an arbitrary marker header */ | |
| 440 { | |
| 441 if (datalen > (unsigned int) 65533) /* safety check */ | |
| 442 ERREXIT(cinfo, JERR_BAD_LENGTH); | |
| 443 | |
| 444 emit_marker(cinfo, (JPEG_MARKER) marker); | |
| 445 | |
| 446 emit_2bytes(cinfo, (int) (datalen + 2)); /* total length */ | |
| 447 } | |
| 448 | |
| 449 METHODDEF(void) | |
| 450 write_marker_byte (j_compress_ptr cinfo, int val) | |
| 451 /* Emit one byte of marker parameters following write_marker_header */ | |
| 452 { | |
| 453 emit_byte(cinfo, val); | |
| 454 } | |
| 455 | |
| 456 | |
| 457 /* | |
| 458 * Write datastream header. | |
| 459 * This consists of an SOI and optional APPn markers. | |
| 460 * We recommend use of the JFIF marker, but not the Adobe marker, | |
| 461 * when using YCbCr or grayscale data. The JFIF marker should NOT | |
| 462 * be used for any other JPEG colorspace. The Adobe marker is helpful | |
| 463 * to distinguish RGB, CMYK, and YCCK colorspaces. | |
| 464 * Note that an application can write additional header markers after | |
| 465 * jpeg_start_compress returns. | |
| 466 */ | |
| 467 | |
| 468 METHODDEF(void) | |
| 469 write_file_header (j_compress_ptr cinfo) | |
| 470 { | |
| 471 my_marker_ptr marker = (my_marker_ptr) cinfo->marker; | |
| 472 | |
| 473 emit_marker(cinfo, M_SOI); /* first the SOI */ | |
| 474 | |
| 475 /* SOI is defined to reset restart interval to 0 */ | |
| 476 marker->last_restart_interval = 0; | |
| 477 | |
| 478 if (cinfo->write_JFIF_header) /* next an optional JFIF APP0 */ | |
| 479 emit_jfif_app0(cinfo); | |
| 480 if (cinfo->write_Adobe_marker) /* next an optional Adobe APP14 */ | |
| 481 emit_adobe_app14(cinfo); | |
| 482 } | |
| 483 | |
| 484 | |
| 485 /* | |
| 486 * Write frame header. | |
| 487 * This consists of DQT and SOFn markers. | |
| 488 * Note that we do not emit the SOF until we have emitted the DQT(s). | |
| 489 * This avoids compatibility problems with incorrect implementations that | |
| 490 * try to error-check the quant table numbers as soon as they see the SOF. | |
| 491 */ | |
| 492 | |
| 493 METHODDEF(void) | |
| 494 write_frame_header (j_compress_ptr cinfo) | |
| 495 { | |
| 496 int ci, prec; | |
| 497 boolean is_baseline; | |
| 498 jpeg_component_info *compptr; | |
| 499 | |
| 500 /* Emit DQT for each quantization table. | |
| 501 * Note that emit_dqt() suppresses any duplicate tables. | |
| 502 */ | |
| 503 prec = 0; | |
| 504 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; | |
| 505 ci++, compptr++) { | |
| 506 prec += emit_dqt(cinfo, compptr->quant_tbl_no); | |
| 507 } | |
| 508 /* now prec is nonzero iff there are any 16-bit quant tables. */ | |
| 509 | |
| 510 /* Check for a non-baseline specification. | |
| 511 * Note we assume that Huffman table numbers won't be changed later. | |
| 512 */ | |
| 513 if (cinfo->arith_code || cinfo->progressive_mode || | |
| 514 cinfo->data_precision != 8) { | |
| 515 is_baseline = FALSE; | |
| 516 } else { | |
| 517 is_baseline = TRUE; | |
| 518 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; | |
| 519 ci++, compptr++) { | |
| 520 if (compptr->dc_tbl_no > 1 || compptr->ac_tbl_no > 1) | |
| 521 is_baseline = FALSE; | |
| 522 } | |
| 523 if (prec && is_baseline) { | |
| 524 is_baseline = FALSE; | |
| 525 /* If it's baseline except for quantizer size, warn the user */ | |
| 526 TRACEMS(cinfo, 0, JTRC_16BIT_TABLES); | |
| 527 } | |
| 528 } | |
| 529 | |
| 530 /* Emit the proper SOF marker */ | |
| 531 if (cinfo->arith_code) { | |
| 532 emit_sof(cinfo, M_SOF9); /* SOF code for arithmetic coding */ | |
| 533 } else { | |
| 534 if (cinfo->progressive_mode) | |
| 535 emit_sof(cinfo, M_SOF2); /* SOF code for progressive Huffman */ | |
| 536 else if (is_baseline) | |
| 537 emit_sof(cinfo, M_SOF0); /* SOF code for baseline implementation */ | |
| 538 else | |
| 539 emit_sof(cinfo, M_SOF1); /* SOF code for non-baseline Huffman file */ | |
| 540 } | |
| 541 } | |
| 542 | |
| 543 | |
| 544 /* | |
| 545 * Write scan header. | |
| 546 * This consists of DHT or DAC markers, optional DRI, and SOS. | |
| 547 * Compressed data will be written following the SOS. | |
| 548 */ | |
| 549 | |
| 550 METHODDEF(void) | |
| 551 write_scan_header (j_compress_ptr cinfo) | |
| 552 { | |
| 553 my_marker_ptr marker = (my_marker_ptr) cinfo->marker; | |
| 554 int i; | |
| 555 jpeg_component_info *compptr; | |
| 556 | |
| 557 if (cinfo->arith_code) { | |
| 558 /* Emit arith conditioning info. We may have some duplication | |
| 559 * if the file has multiple scans, but it's so small it's hardly | |
| 560 * worth worrying about. | |
| 561 */ | |
| 562 emit_dac(cinfo); | |
| 563 } else { | |
| 564 /* Emit Huffman tables. | |
| 565 * Note that emit_dht() suppresses any duplicate tables. | |
| 566 */ | |
| 567 for (i = 0; i < cinfo->comps_in_scan; i++) { | |
| 568 compptr = cinfo->cur_comp_info[i]; | |
| 569 if (cinfo->progressive_mode) { | |
| 570 /* Progressive mode: only DC or only AC tables are used in one scan */ | |
| 571 if (cinfo->Ss == 0) { | |
| 572 if (cinfo->Ah == 0) /* DC needs no table for refinement scan */ | |
| 573 emit_dht(cinfo, compptr->dc_tbl_no, FALSE); | |
| 574 } else { | |
| 575 emit_dht(cinfo, compptr->ac_tbl_no, TRUE); | |
| 576 } | |
| 577 } else { | |
| 578 /* Sequential mode: need both DC and AC tables */ | |
| 579 emit_dht(cinfo, compptr->dc_tbl_no, FALSE); | |
| 580 emit_dht(cinfo, compptr->ac_tbl_no, TRUE); | |
| 581 } | |
| 582 } | |
| 583 } | |
| 584 | |
| 585 /* Emit DRI if required --- note that DRI value could change for each scan. | |
| 586 * We avoid wasting space with unnecessary DRIs, however. | |
| 587 */ | |
| 588 if (cinfo->restart_interval != marker->last_restart_interval) { | |
| 589 emit_dri(cinfo); | |
| 590 marker->last_restart_interval = cinfo->restart_interval; | |
| 591 } | |
| 592 | |
| 593 emit_sos(cinfo); | |
| 594 } | |
| 595 | |
| 596 | |
| 597 /* | |
| 598 * Write datastream trailer. | |
| 599 */ | |
| 600 | |
| 601 METHODDEF(void) | |
| 602 write_file_trailer (j_compress_ptr cinfo) | |
| 603 { | |
| 604 emit_marker(cinfo, M_EOI); | |
| 605 } | |
| 606 | |
| 607 | |
| 608 /* | |
| 609 * Write an abbreviated table-specification datastream. | |
| 610 * This consists of SOI, DQT and DHT tables, and EOI. | |
| 611 * Any table that is defined and not marked sent_table = TRUE will be | |
| 612 * emitted. Note that all tables will be marked sent_table = TRUE at exit. | |
| 613 */ | |
| 614 | |
| 615 METHODDEF(void) | |
| 616 write_tables_only (j_compress_ptr cinfo) | |
| 617 { | |
| 618 int i; | |
| 619 | |
| 620 emit_marker(cinfo, M_SOI); | |
| 621 | |
| 622 for (i = 0; i < NUM_QUANT_TBLS; i++) { | |
| 623 if (cinfo->quant_tbl_ptrs[i] != NULL) | |
| 624 (void) emit_dqt(cinfo, i); | |
| 625 } | |
| 626 | |
| 627 if (! cinfo->arith_code) { | |
| 628 for (i = 0; i < NUM_HUFF_TBLS; i++) { | |
| 629 if (cinfo->dc_huff_tbl_ptrs[i] != NULL) | |
| 630 emit_dht(cinfo, i, FALSE); | |
| 631 if (cinfo->ac_huff_tbl_ptrs[i] != NULL) | |
| 632 emit_dht(cinfo, i, TRUE); | |
| 633 } | |
| 634 } | |
| 635 | |
| 636 emit_marker(cinfo, M_EOI); | |
| 637 } | |
| 638 | |
| 639 | |
| 640 /* | |
| 641 * Initialize the marker writer module. | |
| 642 */ | |
| 643 | |
| 644 GLOBAL(void) | |
| 645 jinit_marker_writer (j_compress_ptr cinfo) | |
| 646 { | |
| 647 my_marker_ptr marker; | |
| 648 | |
| 649 /* Create the subobject */ | |
| 650 marker = (my_marker_ptr) | |
| 651 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, | |
| 652 SIZEOF(my_marker_writer)); | |
| 653 cinfo->marker = (struct jpeg_marker_writer *) marker; | |
| 654 /* Initialize method pointers */ | |
| 655 marker->pub.write_file_header = write_file_header; | |
| 656 marker->pub.write_frame_header = write_frame_header; | |
| 657 marker->pub.write_scan_header = write_scan_header; | |
| 658 marker->pub.write_file_trailer = write_file_trailer; | |
| 659 marker->pub.write_tables_only = write_tables_only; | |
| 660 marker->pub.write_marker_header = write_marker_header; | |
| 661 marker->pub.write_marker_byte = write_marker_byte; | |
| 662 /* Initialize private state */ | |
| 663 marker->last_restart_interval = 0; | |
| 664 } | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 1705523002:
Remove libjpeg and libjpeg_turbo. (Closed)
Base URL: https://github.com/domokit/mojo.git@master