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annotate libs/libjpeg/jcmarker.c @ 0:b2f14e535253

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initial commit
author John Tsiombikas <nuclear@member.fsf.org>
date Sat, 01 Feb 2014 19:58:19 +0200
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nuclear@0 1 /*
nuclear@0 2 * jcmarker.c
nuclear@0 3 *
nuclear@0 4 * Copyright (C) 1991-1998, Thomas G. Lane.
nuclear@0 5 * This file is part of the Independent JPEG Group's software.
nuclear@0 6 * For conditions of distribution and use, see the accompanying README file.
nuclear@0 7 *
nuclear@0 8 * This file contains routines to write JPEG datastream markers.
nuclear@0 9 */
nuclear@0 10
nuclear@0 11 #define JPEG_INTERNALS
nuclear@0 12 #include "jinclude.h"
nuclear@0 13 #include "jpeglib.h"
nuclear@0 14
nuclear@0 15
nuclear@0 16 typedef enum { /* JPEG marker codes */
nuclear@0 17 M_SOF0 = 0xc0,
nuclear@0 18 M_SOF1 = 0xc1,
nuclear@0 19 M_SOF2 = 0xc2,
nuclear@0 20 M_SOF3 = 0xc3,
nuclear@0 21
nuclear@0 22 M_SOF5 = 0xc5,
nuclear@0 23 M_SOF6 = 0xc6,
nuclear@0 24 M_SOF7 = 0xc7,
nuclear@0 25
nuclear@0 26 M_JPG = 0xc8,
nuclear@0 27 M_SOF9 = 0xc9,
nuclear@0 28 M_SOF10 = 0xca,
nuclear@0 29 M_SOF11 = 0xcb,
nuclear@0 30
nuclear@0 31 M_SOF13 = 0xcd,
nuclear@0 32 M_SOF14 = 0xce,
nuclear@0 33 M_SOF15 = 0xcf,
nuclear@0 34
nuclear@0 35 M_DHT = 0xc4,
nuclear@0 36
nuclear@0 37 M_DAC = 0xcc,
nuclear@0 38
nuclear@0 39 M_RST0 = 0xd0,
nuclear@0 40 M_RST1 = 0xd1,
nuclear@0 41 M_RST2 = 0xd2,
nuclear@0 42 M_RST3 = 0xd3,
nuclear@0 43 M_RST4 = 0xd4,
nuclear@0 44 M_RST5 = 0xd5,
nuclear@0 45 M_RST6 = 0xd6,
nuclear@0 46 M_RST7 = 0xd7,
nuclear@0 47
nuclear@0 48 M_SOI = 0xd8,
nuclear@0 49 M_EOI = 0xd9,
nuclear@0 50 M_SOS = 0xda,
nuclear@0 51 M_DQT = 0xdb,
nuclear@0 52 M_DNL = 0xdc,
nuclear@0 53 M_DRI = 0xdd,
nuclear@0 54 M_DHP = 0xde,
nuclear@0 55 M_EXP = 0xdf,
nuclear@0 56
nuclear@0 57 M_APP0 = 0xe0,
nuclear@0 58 M_APP1 = 0xe1,
nuclear@0 59 M_APP2 = 0xe2,
nuclear@0 60 M_APP3 = 0xe3,
nuclear@0 61 M_APP4 = 0xe4,
nuclear@0 62 M_APP5 = 0xe5,
nuclear@0 63 M_APP6 = 0xe6,
nuclear@0 64 M_APP7 = 0xe7,
nuclear@0 65 M_APP8 = 0xe8,
nuclear@0 66 M_APP9 = 0xe9,
nuclear@0 67 M_APP10 = 0xea,
nuclear@0 68 M_APP11 = 0xeb,
nuclear@0 69 M_APP12 = 0xec,
nuclear@0 70 M_APP13 = 0xed,
nuclear@0 71 M_APP14 = 0xee,
nuclear@0 72 M_APP15 = 0xef,
nuclear@0 73
nuclear@0 74 M_JPG0 = 0xf0,
nuclear@0 75 M_JPG13 = 0xfd,
nuclear@0 76 M_COM = 0xfe,
nuclear@0 77
nuclear@0 78 M_TEM = 0x01,
nuclear@0 79
nuclear@0 80 M_ERROR = 0x100
nuclear@0 81 } JPEG_MARKER;
nuclear@0 82
nuclear@0 83
nuclear@0 84 /* Private state */
nuclear@0 85
nuclear@0 86 typedef struct {
nuclear@0 87 struct jpeg_marker_writer pub; /* public fields */
nuclear@0 88
nuclear@0 89 unsigned int last_restart_interval; /* last DRI value emitted; 0 after SOI */
nuclear@0 90 } my_marker_writer;
nuclear@0 91
nuclear@0 92 typedef my_marker_writer * my_marker_ptr;
nuclear@0 93
nuclear@0 94
nuclear@0 95 /*
nuclear@0 96 * Basic output routines.
nuclear@0 97 *
nuclear@0 98 * Note that we do not support suspension while writing a marker.
nuclear@0 99 * Therefore, an application using suspension must ensure that there is
nuclear@0 100 * enough buffer space for the initial markers (typ. 600-700 bytes) before
nuclear@0 101 * calling jpeg_start_compress, and enough space to write the trailing EOI
nuclear@0 102 * (a few bytes) before calling jpeg_finish_compress. Multipass compression
nuclear@0 103 * modes are not supported at all with suspension, so those two are the only
nuclear@0 104 * points where markers will be written.
nuclear@0 105 */
nuclear@0 106
nuclear@0 107 LOCAL(void)
nuclear@0 108 emit_byte (j_compress_ptr cinfo, int val)
nuclear@0 109 /* Emit a byte */
nuclear@0 110 {
nuclear@0 111 struct jpeg_destination_mgr * dest = cinfo->dest;
nuclear@0 112
nuclear@0 113 *(dest->next_output_byte)++ = (JOCTET) val;
nuclear@0 114 if (--dest->free_in_buffer == 0) {
nuclear@0 115 if (! (*dest->empty_output_buffer) (cinfo))
nuclear@0 116 ERREXIT(cinfo, JERR_CANT_SUSPEND);
nuclear@0 117 }
nuclear@0 118 }
nuclear@0 119
nuclear@0 120
nuclear@0 121 LOCAL(void)
nuclear@0 122 emit_marker (j_compress_ptr cinfo, JPEG_MARKER mark)
nuclear@0 123 /* Emit a marker code */
nuclear@0 124 {
nuclear@0 125 emit_byte(cinfo, 0xFF);
nuclear@0 126 emit_byte(cinfo, (int) mark);
nuclear@0 127 }
nuclear@0 128
nuclear@0 129
nuclear@0 130 LOCAL(void)
nuclear@0 131 emit_2bytes (j_compress_ptr cinfo, int value)
nuclear@0 132 /* Emit a 2-byte integer; these are always MSB first in JPEG files */
nuclear@0 133 {
nuclear@0 134 emit_byte(cinfo, (value >> 8) & 0xFF);
nuclear@0 135 emit_byte(cinfo, value & 0xFF);
nuclear@0 136 }
nuclear@0 137
nuclear@0 138
nuclear@0 139 /*
nuclear@0 140 * Routines to write specific marker types.
nuclear@0 141 */
nuclear@0 142
nuclear@0 143 LOCAL(int)
nuclear@0 144 emit_dqt (j_compress_ptr cinfo, int index)
nuclear@0 145 /* Emit a DQT marker */
nuclear@0 146 /* Returns the precision used (0 = 8bits, 1 = 16bits) for baseline checking */
nuclear@0 147 {
nuclear@0 148 JQUANT_TBL * qtbl = cinfo->quant_tbl_ptrs[index];
nuclear@0 149 int prec;
nuclear@0 150 int i;
nuclear@0 151
nuclear@0 152 if (qtbl == NULL)
nuclear@0 153 ERREXIT1(cinfo, JERR_NO_QUANT_TABLE, index);
nuclear@0 154
nuclear@0 155 prec = 0;
nuclear@0 156 for (i = 0; i < DCTSIZE2; i++) {
nuclear@0 157 if (qtbl->quantval[i] > 255)
nuclear@0 158 prec = 1;
nuclear@0 159 }
nuclear@0 160
nuclear@0 161 if (! qtbl->sent_table) {
nuclear@0 162 emit_marker(cinfo, M_DQT);
nuclear@0 163
nuclear@0 164 emit_2bytes(cinfo, prec ? DCTSIZE2*2 + 1 + 2 : DCTSIZE2 + 1 + 2);
nuclear@0 165
nuclear@0 166 emit_byte(cinfo, index + (prec<<4));
nuclear@0 167
nuclear@0 168 for (i = 0; i < DCTSIZE2; i++) {
nuclear@0 169 /* The table entries must be emitted in zigzag order. */
nuclear@0 170 unsigned int qval = qtbl->quantval[jpeg_natural_order[i]];
nuclear@0 171 if (prec)
nuclear@0 172 emit_byte(cinfo, (int) (qval >> 8));
nuclear@0 173 emit_byte(cinfo, (int) (qval & 0xFF));
nuclear@0 174 }
nuclear@0 175
nuclear@0 176 qtbl->sent_table = TRUE;
nuclear@0 177 }
nuclear@0 178
nuclear@0 179 return prec;
nuclear@0 180 }
nuclear@0 181
nuclear@0 182
nuclear@0 183 LOCAL(void)
nuclear@0 184 emit_dht (j_compress_ptr cinfo, int index, boolean is_ac)
nuclear@0 185 /* Emit a DHT marker */
nuclear@0 186 {
nuclear@0 187 JHUFF_TBL * htbl;
nuclear@0 188 int length, i;
nuclear@0 189
nuclear@0 190 if (is_ac) {
nuclear@0 191 htbl = cinfo->ac_huff_tbl_ptrs[index];
nuclear@0 192 index += 0x10; /* output index has AC bit set */
nuclear@0 193 } else {
nuclear@0 194 htbl = cinfo->dc_huff_tbl_ptrs[index];
nuclear@0 195 }
nuclear@0 196
nuclear@0 197 if (htbl == NULL)
nuclear@0 198 ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, index);
nuclear@0 199
nuclear@0 200 if (! htbl->sent_table) {
nuclear@0 201 emit_marker(cinfo, M_DHT);
nuclear@0 202
nuclear@0 203 length = 0;
nuclear@0 204 for (i = 1; i <= 16; i++)
nuclear@0 205 length += htbl->bits[i];
nuclear@0 206
nuclear@0 207 emit_2bytes(cinfo, length + 2 + 1 + 16);
nuclear@0 208 emit_byte(cinfo, index);
nuclear@0 209
nuclear@0 210 for (i = 1; i <= 16; i++)
nuclear@0 211 emit_byte(cinfo, htbl->bits[i]);
nuclear@0 212
nuclear@0 213 for (i = 0; i < length; i++)
nuclear@0 214 emit_byte(cinfo, htbl->huffval[i]);
nuclear@0 215
nuclear@0 216 htbl->sent_table = TRUE;
nuclear@0 217 }
nuclear@0 218 }
nuclear@0 219
nuclear@0 220
nuclear@0 221 LOCAL(void)
nuclear@0 222 emit_dac (j_compress_ptr cinfo)
nuclear@0 223 /* Emit a DAC marker */
nuclear@0 224 /* Since the useful info is so small, we want to emit all the tables in */
nuclear@0 225 /* one DAC marker. Therefore this routine does its own scan of the table. */
nuclear@0 226 {
nuclear@0 227 #ifdef C_ARITH_CODING_SUPPORTED
nuclear@0 228 char dc_in_use[NUM_ARITH_TBLS];
nuclear@0 229 char ac_in_use[NUM_ARITH_TBLS];
nuclear@0 230 int length, i;
nuclear@0 231 jpeg_component_info *compptr;
nuclear@0 232
nuclear@0 233 for (i = 0; i < NUM_ARITH_TBLS; i++)
nuclear@0 234 dc_in_use[i] = ac_in_use[i] = 0;
nuclear@0 235
nuclear@0 236 for (i = 0; i < cinfo->comps_in_scan; i++) {
nuclear@0 237 compptr = cinfo->cur_comp_info[i];
nuclear@0 238 dc_in_use[compptr->dc_tbl_no] = 1;
nuclear@0 239 ac_in_use[compptr->ac_tbl_no] = 1;
nuclear@0 240 }
nuclear@0 241
nuclear@0 242 length = 0;
nuclear@0 243 for (i = 0; i < NUM_ARITH_TBLS; i++)
nuclear@0 244 length += dc_in_use[i] + ac_in_use[i];
nuclear@0 245
nuclear@0 246 emit_marker(cinfo, M_DAC);
nuclear@0 247
nuclear@0 248 emit_2bytes(cinfo, length*2 + 2);
nuclear@0 249
nuclear@0 250 for (i = 0; i < NUM_ARITH_TBLS; i++) {
nuclear@0 251 if (dc_in_use[i]) {
nuclear@0 252 emit_byte(cinfo, i);
nuclear@0 253 emit_byte(cinfo, cinfo->arith_dc_L[i] + (cinfo->arith_dc_U[i]<<4));
nuclear@0 254 }
nuclear@0 255 if (ac_in_use[i]) {
nuclear@0 256 emit_byte(cinfo, i + 0x10);
nuclear@0 257 emit_byte(cinfo, cinfo->arith_ac_K[i]);
nuclear@0 258 }
nuclear@0 259 }
nuclear@0 260 #endif /* C_ARITH_CODING_SUPPORTED */
nuclear@0 261 }
nuclear@0 262
nuclear@0 263
nuclear@0 264 LOCAL(void)
nuclear@0 265 emit_dri (j_compress_ptr cinfo)
nuclear@0 266 /* Emit a DRI marker */
nuclear@0 267 {
nuclear@0 268 emit_marker(cinfo, M_DRI);
nuclear@0 269
nuclear@0 270 emit_2bytes(cinfo, 4); /* fixed length */
nuclear@0 271
nuclear@0 272 emit_2bytes(cinfo, (int) cinfo->restart_interval);
nuclear@0 273 }
nuclear@0 274
nuclear@0 275
nuclear@0 276 LOCAL(void)
nuclear@0 277 emit_sof (j_compress_ptr cinfo, JPEG_MARKER code)
nuclear@0 278 /* Emit a SOF marker */
nuclear@0 279 {
nuclear@0 280 int ci;
nuclear@0 281 jpeg_component_info *compptr;
nuclear@0 282
nuclear@0 283 emit_marker(cinfo, code);
nuclear@0 284
nuclear@0 285 emit_2bytes(cinfo, 3 * cinfo->num_components + 2 + 5 + 1); /* length */
nuclear@0 286
nuclear@0 287 /* Make sure image isn't bigger than SOF field can handle */
nuclear@0 288 if ((long) cinfo->image_height > 65535L ||
nuclear@0 289 (long) cinfo->image_width > 65535L)
nuclear@0 290 ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) 65535);
nuclear@0 291
nuclear@0 292 emit_byte(cinfo, cinfo->data_precision);
nuclear@0 293 emit_2bytes(cinfo, (int) cinfo->image_height);
nuclear@0 294 emit_2bytes(cinfo, (int) cinfo->image_width);
nuclear@0 295
nuclear@0 296 emit_byte(cinfo, cinfo->num_components);
nuclear@0 297
nuclear@0 298 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
nuclear@0 299 ci++, compptr++) {
nuclear@0 300 emit_byte(cinfo, compptr->component_id);
nuclear@0 301 emit_byte(cinfo, (compptr->h_samp_factor << 4) + compptr->v_samp_factor);
nuclear@0 302 emit_byte(cinfo, compptr->quant_tbl_no);
nuclear@0 303 }
nuclear@0 304 }
nuclear@0 305
nuclear@0 306
nuclear@0 307 LOCAL(void)
nuclear@0 308 emit_sos (j_compress_ptr cinfo)
nuclear@0 309 /* Emit a SOS marker */
nuclear@0 310 {
nuclear@0 311 int i, td, ta;
nuclear@0 312 jpeg_component_info *compptr;
nuclear@0 313
nuclear@0 314 emit_marker(cinfo, M_SOS);
nuclear@0 315
nuclear@0 316 emit_2bytes(cinfo, 2 * cinfo->comps_in_scan + 2 + 1 + 3); /* length */
nuclear@0 317
nuclear@0 318 emit_byte(cinfo, cinfo->comps_in_scan);
nuclear@0 319
nuclear@0 320 for (i = 0; i < cinfo->comps_in_scan; i++) {
nuclear@0 321 compptr = cinfo->cur_comp_info[i];
nuclear@0 322 emit_byte(cinfo, compptr->component_id);
nuclear@0 323 td = compptr->dc_tbl_no;
nuclear@0 324 ta = compptr->ac_tbl_no;
nuclear@0 325 if (cinfo->progressive_mode) {
nuclear@0 326 /* Progressive mode: only DC or only AC tables are used in one scan;
nuclear@0 327 * furthermore, Huffman coding of DC refinement uses no table at all.
nuclear@0 328 * We emit 0 for unused field(s); this is recommended by the P&M text
nuclear@0 329 * but does not seem to be specified in the standard.
nuclear@0 330 */
nuclear@0 331 if (cinfo->Ss == 0) {
nuclear@0 332 ta = 0; /* DC scan */
nuclear@0 333 if (cinfo->Ah != 0 && !cinfo->arith_code)
nuclear@0 334 td = 0; /* no DC table either */
nuclear@0 335 } else {
nuclear@0 336 td = 0; /* AC scan */
nuclear@0 337 }
nuclear@0 338 }
nuclear@0 339 emit_byte(cinfo, (td << 4) + ta);
nuclear@0 340 }
nuclear@0 341
nuclear@0 342 emit_byte(cinfo, cinfo->Ss);
nuclear@0 343 emit_byte(cinfo, cinfo->Se);
nuclear@0 344 emit_byte(cinfo, (cinfo->Ah << 4) + cinfo->Al);
nuclear@0 345 }
nuclear@0 346
nuclear@0 347
nuclear@0 348 LOCAL(void)
nuclear@0 349 emit_jfif_app0 (j_compress_ptr cinfo)
nuclear@0 350 /* Emit a JFIF-compliant APP0 marker */
nuclear@0 351 {
nuclear@0 352 /*
nuclear@0 353 * Length of APP0 block (2 bytes)
nuclear@0 354 * Block ID (4 bytes - ASCII "JFIF")
nuclear@0 355 * Zero byte (1 byte to terminate the ID string)
nuclear@0 356 * Version Major, Minor (2 bytes - major first)
nuclear@0 357 * Units (1 byte - 0x00 = none, 0x01 = inch, 0x02 = cm)
nuclear@0 358 * Xdpu (2 bytes - dots per unit horizontal)
nuclear@0 359 * Ydpu (2 bytes - dots per unit vertical)
nuclear@0 360 * Thumbnail X size (1 byte)
nuclear@0 361 * Thumbnail Y size (1 byte)
nuclear@0 362 */
nuclear@0 363
nuclear@0 364 emit_marker(cinfo, M_APP0);
nuclear@0 365
nuclear@0 366 emit_2bytes(cinfo, 2 + 4 + 1 + 2 + 1 + 2 + 2 + 1 + 1); /* length */
nuclear@0 367
nuclear@0 368 emit_byte(cinfo, 0x4A); /* Identifier: ASCII "JFIF" */
nuclear@0 369 emit_byte(cinfo, 0x46);
nuclear@0 370 emit_byte(cinfo, 0x49);
nuclear@0 371 emit_byte(cinfo, 0x46);
nuclear@0 372 emit_byte(cinfo, 0);
nuclear@0 373 emit_byte(cinfo, cinfo->JFIF_major_version); /* Version fields */
nuclear@0 374 emit_byte(cinfo, cinfo->JFIF_minor_version);
nuclear@0 375 emit_byte(cinfo, cinfo->density_unit); /* Pixel size information */
nuclear@0 376 emit_2bytes(cinfo, (int) cinfo->X_density);
nuclear@0 377 emit_2bytes(cinfo, (int) cinfo->Y_density);
nuclear@0 378 emit_byte(cinfo, 0); /* No thumbnail image */
nuclear@0 379 emit_byte(cinfo, 0);
nuclear@0 380 }
nuclear@0 381
nuclear@0 382
nuclear@0 383 LOCAL(void)
nuclear@0 384 emit_adobe_app14 (j_compress_ptr cinfo)
nuclear@0 385 /* Emit an Adobe APP14 marker */
nuclear@0 386 {
nuclear@0 387 /*
nuclear@0 388 * Length of APP14 block (2 bytes)
nuclear@0 389 * Block ID (5 bytes - ASCII "Adobe")
nuclear@0 390 * Version Number (2 bytes - currently 100)
nuclear@0 391 * Flags0 (2 bytes - currently 0)
nuclear@0 392 * Flags1 (2 bytes - currently 0)
nuclear@0 393 * Color transform (1 byte)
nuclear@0 394 *
nuclear@0 395 * Although Adobe TN 5116 mentions Version = 101, all the Adobe files
nuclear@0 396 * now in circulation seem to use Version = 100, so that's what we write.
nuclear@0 397 *
nuclear@0 398 * We write the color transform byte as 1 if the JPEG color space is
nuclear@0 399 * YCbCr, 2 if it's YCCK, 0 otherwise. Adobe's definition has to do with
nuclear@0 400 * whether the encoder performed a transformation, which is pretty useless.
nuclear@0 401 */
nuclear@0 402
nuclear@0 403 emit_marker(cinfo, M_APP14);
nuclear@0 404
nuclear@0 405 emit_2bytes(cinfo, 2 + 5 + 2 + 2 + 2 + 1); /* length */
nuclear@0 406
nuclear@0 407 emit_byte(cinfo, 0x41); /* Identifier: ASCII "Adobe" */
nuclear@0 408 emit_byte(cinfo, 0x64);
nuclear@0 409 emit_byte(cinfo, 0x6F);
nuclear@0 410 emit_byte(cinfo, 0x62);
nuclear@0 411 emit_byte(cinfo, 0x65);
nuclear@0 412 emit_2bytes(cinfo, 100); /* Version */
nuclear@0 413 emit_2bytes(cinfo, 0); /* Flags0 */
nuclear@0 414 emit_2bytes(cinfo, 0); /* Flags1 */
nuclear@0 415 switch (cinfo->jpeg_color_space) {
nuclear@0 416 case JCS_YCbCr:
nuclear@0 417 emit_byte(cinfo, 1); /* Color transform = 1 */
nuclear@0 418 break;
nuclear@0 419 case JCS_YCCK:
nuclear@0 420 emit_byte(cinfo, 2); /* Color transform = 2 */
nuclear@0 421 break;
nuclear@0 422 default:
nuclear@0 423 emit_byte(cinfo, 0); /* Color transform = 0 */
nuclear@0 424 break;
nuclear@0 425 }
nuclear@0 426 }
nuclear@0 427
nuclear@0 428
nuclear@0 429 /*
nuclear@0 430 * These routines allow writing an arbitrary marker with parameters.
nuclear@0 431 * The only intended use is to emit COM or APPn markers after calling
nuclear@0 432 * write_file_header and before calling write_frame_header.
nuclear@0 433 * Other uses are not guaranteed to produce desirable results.
nuclear@0 434 * Counting the parameter bytes properly is the caller's responsibility.
nuclear@0 435 */
nuclear@0 436
nuclear@0 437 METHODDEF(void)
nuclear@0 438 write_marker_header (j_compress_ptr cinfo, int marker, unsigned int datalen)
nuclear@0 439 /* Emit an arbitrary marker header */
nuclear@0 440 {
nuclear@0 441 if (datalen > (unsigned int) 65533) /* safety check */
nuclear@0 442 ERREXIT(cinfo, JERR_BAD_LENGTH);
nuclear@0 443
nuclear@0 444 emit_marker(cinfo, (JPEG_MARKER) marker);
nuclear@0 445
nuclear@0 446 emit_2bytes(cinfo, (int) (datalen + 2)); /* total length */
nuclear@0 447 }
nuclear@0 448
nuclear@0 449 METHODDEF(void)
nuclear@0 450 write_marker_byte (j_compress_ptr cinfo, int val)
nuclear@0 451 /* Emit one byte of marker parameters following write_marker_header */
nuclear@0 452 {
nuclear@0 453 emit_byte(cinfo, val);
nuclear@0 454 }
nuclear@0 455
nuclear@0 456
nuclear@0 457 /*
nuclear@0 458 * Write datastream header.
nuclear@0 459 * This consists of an SOI and optional APPn markers.
nuclear@0 460 * We recommend use of the JFIF marker, but not the Adobe marker,
nuclear@0 461 * when using YCbCr or grayscale data. The JFIF marker should NOT
nuclear@0 462 * be used for any other JPEG colorspace. The Adobe marker is helpful
nuclear@0 463 * to distinguish RGB, CMYK, and YCCK colorspaces.
nuclear@0 464 * Note that an application can write additional header markers after
nuclear@0 465 * jpeg_start_compress returns.
nuclear@0 466 */
nuclear@0 467
nuclear@0 468 METHODDEF(void)
nuclear@0 469 write_file_header (j_compress_ptr cinfo)
nuclear@0 470 {
nuclear@0 471 my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
nuclear@0 472
nuclear@0 473 emit_marker(cinfo, M_SOI); /* first the SOI */
nuclear@0 474
nuclear@0 475 /* SOI is defined to reset restart interval to 0 */
nuclear@0 476 marker->last_restart_interval = 0;
nuclear@0 477
nuclear@0 478 if (cinfo->write_JFIF_header) /* next an optional JFIF APP0 */
nuclear@0 479 emit_jfif_app0(cinfo);
nuclear@0 480 if (cinfo->write_Adobe_marker) /* next an optional Adobe APP14 */
nuclear@0 481 emit_adobe_app14(cinfo);
nuclear@0 482 }
nuclear@0 483
nuclear@0 484
nuclear@0 485 /*
nuclear@0 486 * Write frame header.
nuclear@0 487 * This consists of DQT and SOFn markers.
nuclear@0 488 * Note that we do not emit the SOF until we have emitted the DQT(s).
nuclear@0 489 * This avoids compatibility problems with incorrect implementations that
nuclear@0 490 * try to error-check the quant table numbers as soon as they see the SOF.
nuclear@0 491 */
nuclear@0 492
nuclear@0 493 METHODDEF(void)
nuclear@0 494 write_frame_header (j_compress_ptr cinfo)
nuclear@0 495 {
nuclear@0 496 int ci, prec;
nuclear@0 497 boolean is_baseline;
nuclear@0 498 jpeg_component_info *compptr;
nuclear@0 499
nuclear@0 500 /* Emit DQT for each quantization table.
nuclear@0 501 * Note that emit_dqt() suppresses any duplicate tables.
nuclear@0 502 */
nuclear@0 503 prec = 0;
nuclear@0 504 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
nuclear@0 505 ci++, compptr++) {
nuclear@0 506 prec += emit_dqt(cinfo, compptr->quant_tbl_no);
nuclear@0 507 }
nuclear@0 508 /* now prec is nonzero iff there are any 16-bit quant tables. */
nuclear@0 509
nuclear@0 510 /* Check for a non-baseline specification.
nuclear@0 511 * Note we assume that Huffman table numbers won't be changed later.
nuclear@0 512 */
nuclear@0 513 if (cinfo->arith_code || cinfo->progressive_mode ||
nuclear@0 514 cinfo->data_precision != 8) {
nuclear@0 515 is_baseline = FALSE;
nuclear@0 516 } else {
nuclear@0 517 is_baseline = TRUE;
nuclear@0 518 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
nuclear@0 519 ci++, compptr++) {
nuclear@0 520 if (compptr->dc_tbl_no > 1 || compptr->ac_tbl_no > 1)
nuclear@0 521 is_baseline = FALSE;
nuclear@0 522 }
nuclear@0 523 if (prec && is_baseline) {
nuclear@0 524 is_baseline = FALSE;
nuclear@0 525 /* If it's baseline except for quantizer size, warn the user */
nuclear@0 526 TRACEMS(cinfo, 0, JTRC_16BIT_TABLES);
nuclear@0 527 }
nuclear@0 528 }
nuclear@0 529
nuclear@0 530 /* Emit the proper SOF marker */
nuclear@0 531 if (cinfo->arith_code) {
nuclear@0 532 emit_sof(cinfo, M_SOF9); /* SOF code for arithmetic coding */
nuclear@0 533 } else {
nuclear@0 534 if (cinfo->progressive_mode)
nuclear@0 535 emit_sof(cinfo, M_SOF2); /* SOF code for progressive Huffman */
nuclear@0 536 else if (is_baseline)
nuclear@0 537 emit_sof(cinfo, M_SOF0); /* SOF code for baseline implementation */
nuclear@0 538 else
nuclear@0 539 emit_sof(cinfo, M_SOF1); /* SOF code for non-baseline Huffman file */
nuclear@0 540 }
nuclear@0 541 }
nuclear@0 542
nuclear@0 543
nuclear@0 544 /*
nuclear@0 545 * Write scan header.
nuclear@0 546 * This consists of DHT or DAC markers, optional DRI, and SOS.
nuclear@0 547 * Compressed data will be written following the SOS.
nuclear@0 548 */
nuclear@0 549
nuclear@0 550 METHODDEF(void)
nuclear@0 551 write_scan_header (j_compress_ptr cinfo)
nuclear@0 552 {
nuclear@0 553 my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
nuclear@0 554 int i;
nuclear@0 555 jpeg_component_info *compptr;
nuclear@0 556
nuclear@0 557 if (cinfo->arith_code) {
nuclear@0 558 /* Emit arith conditioning info. We may have some duplication
nuclear@0 559 * if the file has multiple scans, but it's so small it's hardly
nuclear@0 560 * worth worrying about.
nuclear@0 561 */
nuclear@0 562 emit_dac(cinfo);
nuclear@0 563 } else {
nuclear@0 564 /* Emit Huffman tables.
nuclear@0 565 * Note that emit_dht() suppresses any duplicate tables.
nuclear@0 566 */
nuclear@0 567 for (i = 0; i < cinfo->comps_in_scan; i++) {
nuclear@0 568 compptr = cinfo->cur_comp_info[i];
nuclear@0 569 if (cinfo->progressive_mode) {
nuclear@0 570 /* Progressive mode: only DC or only AC tables are used in one scan */
nuclear@0 571 if (cinfo->Ss == 0) {
nuclear@0 572 if (cinfo->Ah == 0) /* DC needs no table for refinement scan */
nuclear@0 573 emit_dht(cinfo, compptr->dc_tbl_no, FALSE);
nuclear@0 574 } else {
nuclear@0 575 emit_dht(cinfo, compptr->ac_tbl_no, TRUE);
nuclear@0 576 }
nuclear@0 577 } else {
nuclear@0 578 /* Sequential mode: need both DC and AC tables */
nuclear@0 579 emit_dht(cinfo, compptr->dc_tbl_no, FALSE);
nuclear@0 580 emit_dht(cinfo, compptr->ac_tbl_no, TRUE);
nuclear@0 581 }
nuclear@0 582 }
nuclear@0 583 }
nuclear@0 584
nuclear@0 585 /* Emit DRI if required --- note that DRI value could change for each scan.
nuclear@0 586 * We avoid wasting space with unnecessary DRIs, however.
nuclear@0 587 */
nuclear@0 588 if (cinfo->restart_interval != marker->last_restart_interval) {
nuclear@0 589 emit_dri(cinfo);
nuclear@0 590 marker->last_restart_interval = cinfo->restart_interval;
nuclear@0 591 }
nuclear@0 592
nuclear@0 593 emit_sos(cinfo);
nuclear@0 594 }
nuclear@0 595
nuclear@0 596
nuclear@0 597 /*
nuclear@0 598 * Write datastream trailer.
nuclear@0 599 */
nuclear@0 600
nuclear@0 601 METHODDEF(void)
nuclear@0 602 write_file_trailer (j_compress_ptr cinfo)
nuclear@0 603 {
nuclear@0 604 emit_marker(cinfo, M_EOI);
nuclear@0 605 }
nuclear@0 606
nuclear@0 607
nuclear@0 608 /*
nuclear@0 609 * Write an abbreviated table-specification datastream.
nuclear@0 610 * This consists of SOI, DQT and DHT tables, and EOI.
nuclear@0 611 * Any table that is defined and not marked sent_table = TRUE will be
nuclear@0 612 * emitted. Note that all tables will be marked sent_table = TRUE at exit.
nuclear@0 613 */
nuclear@0 614
nuclear@0 615 METHODDEF(void)
nuclear@0 616 write_tables_only (j_compress_ptr cinfo)
nuclear@0 617 {
nuclear@0 618 int i;
nuclear@0 619
nuclear@0 620 emit_marker(cinfo, M_SOI);
nuclear@0 621
nuclear@0 622 for (i = 0; i < NUM_QUANT_TBLS; i++) {
nuclear@0 623 if (cinfo->quant_tbl_ptrs[i] != NULL)
nuclear@0 624 (void) emit_dqt(cinfo, i);
nuclear@0 625 }
nuclear@0 626
nuclear@0 627 if (! cinfo->arith_code) {
nuclear@0 628 for (i = 0; i < NUM_HUFF_TBLS; i++) {
nuclear@0 629 if (cinfo->dc_huff_tbl_ptrs[i] != NULL)
nuclear@0 630 emit_dht(cinfo, i, FALSE);
nuclear@0 631 if (cinfo->ac_huff_tbl_ptrs[i] != NULL)
nuclear@0 632 emit_dht(cinfo, i, TRUE);
nuclear@0 633 }
nuclear@0 634 }
nuclear@0 635
nuclear@0 636 emit_marker(cinfo, M_EOI);
nuclear@0 637 }
nuclear@0 638
nuclear@0 639
nuclear@0 640 /*
nuclear@0 641 * Initialize the marker writer module.
nuclear@0 642 */
nuclear@0 643
nuclear@0 644 GLOBAL(void)
nuclear@0 645 jinit_marker_writer (j_compress_ptr cinfo)
nuclear@0 646 {
nuclear@0 647 my_marker_ptr marker;
nuclear@0 648
nuclear@0 649 /* Create the subobject */
nuclear@0 650 marker = (my_marker_ptr)
nuclear@0 651 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
nuclear@0 652 SIZEOF(my_marker_writer));
nuclear@0 653 cinfo->marker = (struct jpeg_marker_writer *) marker;
nuclear@0 654 /* Initialize method pointers */
nuclear@0 655 marker->pub.write_file_header = write_file_header;
nuclear@0 656 marker->pub.write_frame_header = write_frame_header;
nuclear@0 657 marker->pub.write_scan_header = write_scan_header;
nuclear@0 658 marker->pub.write_file_trailer = write_file_trailer;
nuclear@0 659 marker->pub.write_tables_only = write_tables_only;
nuclear@0 660 marker->pub.write_marker_header = write_marker_header;
nuclear@0 661 marker->pub.write_marker_byte = write_marker_byte;
nuclear@0 662 /* Initialize private state */
nuclear@0 663 marker->last_restart_interval = 0;
nuclear@0 664 }