1/*
2 * jcmarker.c
3 *
4 * This file was part of the Independent JPEG Group's software:
5 * Copyright (C) 1991-1998, Thomas G. Lane.
6 * Modified 2003-2010 by Guido Vollbeding.
7 * libjpeg-turbo Modifications:
8 * Copyright (C) 2010, D. R. Commander.
9 * For conditions of distribution and use, see the accompanying README.ijg
10 * file.
11 *
12 * This file contains routines to write JPEG datastream markers.
13 */
14
15#define JPEG_INTERNALS
16#include "jinclude.h"
17#include "jpeglib.h"
18#include "jpegcomp.h"
19
20
21typedef enum { /* JPEG marker codes */
22 M_SOF0 = 0xc0,
23 M_SOF1 = 0xc1,
24 M_SOF2 = 0xc2,
25 M_SOF3 = 0xc3,
26
27 M_SOF5 = 0xc5,
28 M_SOF6 = 0xc6,
29 M_SOF7 = 0xc7,
30
31 M_JPG = 0xc8,
32 M_SOF9 = 0xc9,
33 M_SOF10 = 0xca,
34 M_SOF11 = 0xcb,
35
36 M_SOF13 = 0xcd,
37 M_SOF14 = 0xce,
38 M_SOF15 = 0xcf,
39
40 M_DHT = 0xc4,
41
42 M_DAC = 0xcc,
43
44 M_RST0 = 0xd0,
45 M_RST1 = 0xd1,
46 M_RST2 = 0xd2,
47 M_RST3 = 0xd3,
48 M_RST4 = 0xd4,
49 M_RST5 = 0xd5,
50 M_RST6 = 0xd6,
51 M_RST7 = 0xd7,
52
53 M_SOI = 0xd8,
54 M_EOI = 0xd9,
55 M_SOS = 0xda,
56 M_DQT = 0xdb,
57 M_DNL = 0xdc,
58 M_DRI = 0xdd,
59 M_DHP = 0xde,
60 M_EXP = 0xdf,
61
62 M_APP0 = 0xe0,
63 M_APP1 = 0xe1,
64 M_APP2 = 0xe2,
65 M_APP3 = 0xe3,
66 M_APP4 = 0xe4,
67 M_APP5 = 0xe5,
68 M_APP6 = 0xe6,
69 M_APP7 = 0xe7,
70 M_APP8 = 0xe8,
71 M_APP9 = 0xe9,
72 M_APP10 = 0xea,
73 M_APP11 = 0xeb,
74 M_APP12 = 0xec,
75 M_APP13 = 0xed,
76 M_APP14 = 0xee,
77 M_APP15 = 0xef,
78
79 M_JPG0 = 0xf0,
80 M_JPG13 = 0xfd,
81 M_COM = 0xfe,
82
83 M_TEM = 0x01,
84
85 M_ERROR = 0x100
86} JPEG_MARKER;
87
88
89/* Private state */
90
91typedef struct {
92 struct jpeg_marker_writer pub; /* public fields */
93
94 unsigned int last_restart_interval; /* last DRI value emitted; 0 after SOI */
95} my_marker_writer;
96
97typedef my_marker_writer *my_marker_ptr;
98
99
100/*
101 * Basic output routines.
102 *
103 * Note that we do not support suspension while writing a marker.
104 * Therefore, an application using suspension must ensure that there is
105 * enough buffer space for the initial markers (typ. 600-700 bytes) before
106 * calling jpeg_start_compress, and enough space to write the trailing EOI
107 * (a few bytes) before calling jpeg_finish_compress. Multipass compression
108 * modes are not supported at all with suspension, so those two are the only
109 * points where markers will be written.
110 */
111
112LOCAL(void)
113emit_byte(j_compress_ptr cinfo, int val)
114/* Emit a byte */
115{
116 struct jpeg_destination_mgr *dest = cinfo->dest;
117
118 *(dest->next_output_byte)++ = (JOCTET)val;
119 if (--dest->free_in_buffer == 0) {
120 if (!(*dest->empty_output_buffer) (cinfo))
121 ERREXIT(cinfo, JERR_CANT_SUSPEND);
122 }
123}
124
125
126LOCAL(void)
127emit_marker(j_compress_ptr cinfo, JPEG_MARKER mark)
128/* Emit a marker code */
129{
130 emit_byte(cinfo, 0xFF);
131 emit_byte(cinfo, (int)mark);
132}
133
134
135LOCAL(void)
136emit_2bytes(j_compress_ptr cinfo, int value)
137/* Emit a 2-byte integer; these are always MSB first in JPEG files */
138{
139 emit_byte(cinfo, (value >> 8) & 0xFF);
140 emit_byte(cinfo, value & 0xFF);
141}
142
143
144/*
145 * Routines to write specific marker types.
146 */
147
148LOCAL(int)
149emit_dqt(j_compress_ptr cinfo, int index)
150/* Emit a DQT marker */
151/* Returns the precision used (0 = 8bits, 1 = 16bits) for baseline checking */
152{
153 JQUANT_TBL *qtbl = cinfo->quant_tbl_ptrs[index];
154 int prec;
155 int i;
156
157 if (qtbl == NULL)
158 ERREXIT1(cinfo, JERR_NO_QUANT_TABLE, index);
159
160 prec = 0;
161 for (i = 0; i < DCTSIZE2; i++) {
162 if (qtbl->quantval[i] > 255)
163 prec = 1;
164 }
165
166 if (!qtbl->sent_table) {
167 emit_marker(cinfo, M_DQT);
168
169 emit_2bytes(cinfo, prec ? DCTSIZE2 * 2 + 1 + 2 : DCTSIZE2 + 1 + 2);
170
171 emit_byte(cinfo, index + (prec << 4));
172
173 for (i = 0; i < DCTSIZE2; i++) {
174 /* The table entries must be emitted in zigzag order. */
175 unsigned int qval = qtbl->quantval[jpeg_natural_order[i]];
176 if (prec)
177 emit_byte(cinfo, (int)(qval >> 8));
178 emit_byte(cinfo, (int)(qval & 0xFF));
179 }
180
181 qtbl->sent_table = TRUE;
182 }
183
184 return prec;
185}
186
187
188LOCAL(void)
189emit_dht(j_compress_ptr cinfo, int index, boolean is_ac)
190/* Emit a DHT marker */
191{
192 JHUFF_TBL *htbl;
193 int length, i;
194
195 if (is_ac) {
196 htbl = cinfo->ac_huff_tbl_ptrs[index];
197 index += 0x10; /* output index has AC bit set */
198 } else {
199 htbl = cinfo->dc_huff_tbl_ptrs[index];
200 }
201
202 if (htbl == NULL)
203 ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, index);
204
205 if (!htbl->sent_table) {
206 emit_marker(cinfo, M_DHT);
207
208 length = 0;
209 for (i = 1; i <= 16; i++)
210 length += htbl->bits[i];
211
212 emit_2bytes(cinfo, length + 2 + 1 + 16);
213 emit_byte(cinfo, index);
214
215 for (i = 1; i <= 16; i++)
216 emit_byte(cinfo, htbl->bits[i]);
217
218 for (i = 0; i < length; i++)
219 emit_byte(cinfo, htbl->huffval[i]);
220
221 htbl->sent_table = TRUE;
222 }
223}
224
225
226LOCAL(void)
227emit_dac(j_compress_ptr cinfo)
228/* Emit a DAC marker */
229/* Since the useful info is so small, we want to emit all the tables in */
230/* one DAC marker. Therefore this routine does its own scan of the table. */
231{
232#ifdef C_ARITH_CODING_SUPPORTED
233 char dc_in_use[NUM_ARITH_TBLS];
234 char ac_in_use[NUM_ARITH_TBLS];
235 int length, i;
236 jpeg_component_info *compptr;
237
238 for (i = 0; i < NUM_ARITH_TBLS; i++)
239 dc_in_use[i] = ac_in_use[i] = 0;
240
241 for (i = 0; i < cinfo->comps_in_scan; i++) {
242 compptr = cinfo->cur_comp_info[i];
243 /* DC needs no table for refinement scan */
244 if (cinfo->Ss == 0 && cinfo->Ah == 0)
245 dc_in_use[compptr->dc_tbl_no] = 1;
246 /* AC needs no table when not present */
247 if (cinfo->Se)
248 ac_in_use[compptr->ac_tbl_no] = 1;
249 }
250
251 length = 0;
252 for (i = 0; i < NUM_ARITH_TBLS; i++)
253 length += dc_in_use[i] + ac_in_use[i];
254
255 if (length) {
256 emit_marker(cinfo, M_DAC);
257
258 emit_2bytes(cinfo, length * 2 + 2);
259
260 for (i = 0; i < NUM_ARITH_TBLS; i++) {
261 if (dc_in_use[i]) {
262 emit_byte(cinfo, i);
263 emit_byte(cinfo, cinfo->arith_dc_L[i] + (cinfo->arith_dc_U[i] << 4));
264 }
265 if (ac_in_use[i]) {
266 emit_byte(cinfo, i + 0x10);
267 emit_byte(cinfo, cinfo->arith_ac_K[i]);
268 }
269 }
270 }
271#endif /* C_ARITH_CODING_SUPPORTED */
272}
273
274
275LOCAL(void)
276emit_dri(j_compress_ptr cinfo)
277/* Emit a DRI marker */
278{
279 emit_marker(cinfo, M_DRI);
280
281 emit_2bytes(cinfo, 4); /* fixed length */
282
283 emit_2bytes(cinfo, (int)cinfo->restart_interval);
284}
285
286
287LOCAL(void)
288emit_sof(j_compress_ptr cinfo, JPEG_MARKER code)
289/* Emit a SOF marker */
290{
291 int ci;
292 jpeg_component_info *compptr;
293
294 emit_marker(cinfo, code);
295
296 emit_2bytes(cinfo, 3 * cinfo->num_components + 2 + 5 + 1); /* length */
297
298 /* Make sure image isn't bigger than SOF field can handle */
299 if ((long)cinfo->_jpeg_height > 65535L || (long)cinfo->_jpeg_width > 65535L)
300 ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int)65535);
301
302 emit_byte(cinfo, cinfo->data_precision);
303 emit_2bytes(cinfo, (int)cinfo->_jpeg_height);
304 emit_2bytes(cinfo, (int)cinfo->_jpeg_width);
305
306 emit_byte(cinfo, cinfo->num_components);
307
308 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
309 ci++, compptr++) {
310 emit_byte(cinfo, compptr->component_id);
311 emit_byte(cinfo, (compptr->h_samp_factor << 4) + compptr->v_samp_factor);
312 emit_byte(cinfo, compptr->quant_tbl_no);
313 }
314}
315
316
317LOCAL(void)
318emit_sos(j_compress_ptr cinfo)
319/* Emit a SOS marker */
320{
321 int i, td, ta;
322 jpeg_component_info *compptr;
323
324 emit_marker(cinfo, M_SOS);
325
326 emit_2bytes(cinfo, 2 * cinfo->comps_in_scan + 2 + 1 + 3); /* length */
327
328 emit_byte(cinfo, cinfo->comps_in_scan);
329
330 for (i = 0; i < cinfo->comps_in_scan; i++) {
331 compptr = cinfo->cur_comp_info[i];
332 emit_byte(cinfo, compptr->component_id);
333
334 /* We emit 0 for unused field(s); this is recommended by the P&M text
335 * but does not seem to be specified in the standard.
336 */
337
338 /* DC needs no table for refinement scan */
339 td = cinfo->Ss == 0 && cinfo->Ah == 0 ? compptr->dc_tbl_no : 0;
340 /* AC needs no table when not present */
341 ta = cinfo->Se ? compptr->ac_tbl_no : 0;
342
343 emit_byte(cinfo, (td << 4) + ta);
344 }
345
346 emit_byte(cinfo, cinfo->Ss);
347 emit_byte(cinfo, cinfo->Se);
348 emit_byte(cinfo, (cinfo->Ah << 4) + cinfo->Al);
349}
350
351
352LOCAL(void)
353emit_jfif_app0(j_compress_ptr cinfo)
354/* Emit a JFIF-compliant APP0 marker */
355{
356 /*
357 * Length of APP0 block (2 bytes)
358 * Block ID (4 bytes - ASCII "JFIF")
359 * Zero byte (1 byte to terminate the ID string)
360 * Version Major, Minor (2 bytes - major first)
361 * Units (1 byte - 0x00 = none, 0x01 = inch, 0x02 = cm)
362 * Xdpu (2 bytes - dots per unit horizontal)
363 * Ydpu (2 bytes - dots per unit vertical)
364 * Thumbnail X size (1 byte)
365 * Thumbnail Y size (1 byte)
366 */
367
368 emit_marker(cinfo, M_APP0);
369
370 emit_2bytes(cinfo, 2 + 4 + 1 + 2 + 1 + 2 + 2 + 1 + 1); /* length */
371
372 emit_byte(cinfo, 0x4A); /* Identifier: ASCII "JFIF" */
373 emit_byte(cinfo, 0x46);
374 emit_byte(cinfo, 0x49);
375 emit_byte(cinfo, 0x46);
376 emit_byte(cinfo, 0);
377 emit_byte(cinfo, cinfo->JFIF_major_version); /* Version fields */
378 emit_byte(cinfo, cinfo->JFIF_minor_version);
379 emit_byte(cinfo, cinfo->density_unit); /* Pixel size information */
380 emit_2bytes(cinfo, (int)cinfo->X_density);
381 emit_2bytes(cinfo, (int)cinfo->Y_density);
382 emit_byte(cinfo, 0); /* No thumbnail image */
383 emit_byte(cinfo, 0);
384}
385
386
387LOCAL(void)
388emit_adobe_app14(j_compress_ptr cinfo)
389/* Emit an Adobe APP14 marker */
390{
391 /*
392 * Length of APP14 block (2 bytes)
393 * Block ID (5 bytes - ASCII "Adobe")
394 * Version Number (2 bytes - currently 100)
395 * Flags0 (2 bytes - currently 0)
396 * Flags1 (2 bytes - currently 0)
397 * Color transform (1 byte)
398 *
399 * Although Adobe TN 5116 mentions Version = 101, all the Adobe files
400 * now in circulation seem to use Version = 100, so that's what we write.
401 *
402 * We write the color transform byte as 1 if the JPEG color space is
403 * YCbCr, 2 if it's YCCK, 0 otherwise. Adobe's definition has to do with
404 * whether the encoder performed a transformation, which is pretty useless.
405 */
406
407 emit_marker(cinfo, M_APP14);
408
409 emit_2bytes(cinfo, 2 + 5 + 2 + 2 + 2 + 1); /* length */
410
411 emit_byte(cinfo, 0x41); /* Identifier: ASCII "Adobe" */
412 emit_byte(cinfo, 0x64);
413 emit_byte(cinfo, 0x6F);
414 emit_byte(cinfo, 0x62);
415 emit_byte(cinfo, 0x65);
416 emit_2bytes(cinfo, 100); /* Version */
417 emit_2bytes(cinfo, 0); /* Flags0 */
418 emit_2bytes(cinfo, 0); /* Flags1 */
419 switch (cinfo->jpeg_color_space) {
420 case JCS_YCbCr:
421 emit_byte(cinfo, 1); /* Color transform = 1 */
422 break;
423 case JCS_YCCK:
424 emit_byte(cinfo, 2); /* Color transform = 2 */
425 break;
426 default:
427 emit_byte(cinfo, 0); /* Color transform = 0 */
428 break;
429 }
430}
431
432
433/*
434 * These routines allow writing an arbitrary marker with parameters.
435 * The only intended use is to emit COM or APPn markers after calling
436 * write_file_header and before calling write_frame_header.
437 * Other uses are not guaranteed to produce desirable results.
438 * Counting the parameter bytes properly is the caller's responsibility.
439 */
440
441METHODDEF(void)
442write_marker_header(j_compress_ptr cinfo, int marker, unsigned int datalen)
443/* Emit an arbitrary marker header */
444{
445 if (datalen > (unsigned int)65533) /* safety check */
446 ERREXIT(cinfo, JERR_BAD_LENGTH);
447
448 emit_marker(cinfo, (JPEG_MARKER)marker);
449
450 emit_2bytes(cinfo, (int)(datalen + 2)); /* total length */
451}
452
453METHODDEF(void)
454write_marker_byte(j_compress_ptr cinfo, int val)
455/* Emit one byte of marker parameters following write_marker_header */
456{
457 emit_byte(cinfo, val);
458}
459
460
461/*
462 * Write datastream header.
463 * This consists of an SOI and optional APPn markers.
464 * We recommend use of the JFIF marker, but not the Adobe marker,
465 * when using YCbCr or grayscale data. The JFIF marker should NOT
466 * be used for any other JPEG colorspace. The Adobe marker is helpful
467 * to distinguish RGB, CMYK, and YCCK colorspaces.
468 * Note that an application can write additional header markers after
469 * jpeg_start_compress returns.
470 */
471
472METHODDEF(void)
473write_file_header(j_compress_ptr cinfo)
474{
475 my_marker_ptr marker = (my_marker_ptr)cinfo->marker;
476
477 emit_marker(cinfo, M_SOI); /* first the SOI */
478
479 /* SOI is defined to reset restart interval to 0 */
480 marker->last_restart_interval = 0;
481
482 if (cinfo->write_JFIF_header) /* next an optional JFIF APP0 */
483 emit_jfif_app0(cinfo);
484 if (cinfo->write_Adobe_marker) /* next an optional Adobe APP14 */
485 emit_adobe_app14(cinfo);
486}
487
488
489/*
490 * Write frame header.
491 * This consists of DQT and SOFn markers.
492 * Note that we do not emit the SOF until we have emitted the DQT(s).
493 * This avoids compatibility problems with incorrect implementations that
494 * try to error-check the quant table numbers as soon as they see the SOF.
495 */
496
497METHODDEF(void)
498write_frame_header(j_compress_ptr cinfo)
499{
500 int ci, prec;
501 boolean is_baseline;
502 jpeg_component_info *compptr;
503
504 /* Emit DQT for each quantization table.
505 * Note that emit_dqt() suppresses any duplicate tables.
506 */
507 prec = 0;
508 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
509 ci++, compptr++) {
510 prec += emit_dqt(cinfo, compptr->quant_tbl_no);
511 }
512 /* now prec is nonzero iff there are any 16-bit quant tables. */
513
514 /* Check for a non-baseline specification.
515 * Note we assume that Huffman table numbers won't be changed later.
516 */
517 if (cinfo->arith_code || cinfo->progressive_mode ||
518 cinfo->data_precision != 8) {
519 is_baseline = FALSE;
520 } else {
521 is_baseline = TRUE;
522 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
523 ci++, compptr++) {
524 if (compptr->dc_tbl_no > 1 || compptr->ac_tbl_no > 1)
525 is_baseline = FALSE;
526 }
527 if (prec && is_baseline) {
528 is_baseline = FALSE;
529 /* If it's baseline except for quantizer size, warn the user */
530 TRACEMS(cinfo, 0, JTRC_16BIT_TABLES);
531 }
532 }
533
534 /* Emit the proper SOF marker */
535 if (cinfo->arith_code) {
536 if (cinfo->progressive_mode)
537 emit_sof(cinfo, M_SOF10); /* SOF code for progressive arithmetic */
538 else
539 emit_sof(cinfo, M_SOF9); /* SOF code for sequential arithmetic */
540 } else {
541 if (cinfo->progressive_mode)
542 emit_sof(cinfo, M_SOF2); /* SOF code for progressive Huffman */
543 else if (is_baseline)
544 emit_sof(cinfo, M_SOF0); /* SOF code for baseline implementation */
545 else
546 emit_sof(cinfo, M_SOF1); /* SOF code for non-baseline Huffman file */
547 }
548}
549
550
551/*
552 * Write scan header.
553 * This consists of DHT or DAC markers, optional DRI, and SOS.
554 * Compressed data will be written following the SOS.
555 */
556
557METHODDEF(void)
558write_scan_header(j_compress_ptr cinfo)
559{
560 my_marker_ptr marker = (my_marker_ptr)cinfo->marker;
561 int i;
562 jpeg_component_info *compptr;
563
564 if (cinfo->arith_code) {
565 /* Emit arith conditioning info. We may have some duplication
566 * if the file has multiple scans, but it's so small it's hardly
567 * worth worrying about.
568 */
569 emit_dac(cinfo);
570 } else {
571 /* Emit Huffman tables.
572 * Note that emit_dht() suppresses any duplicate tables.
573 */
574 for (i = 0; i < cinfo->comps_in_scan; i++) {
575 compptr = cinfo->cur_comp_info[i];
576 /* DC needs no table for refinement scan */
577 if (cinfo->Ss == 0 && cinfo->Ah == 0)
578 emit_dht(cinfo, compptr->dc_tbl_no, FALSE);
579 /* AC needs no table when not present */
580 if (cinfo->Se)
581 emit_dht(cinfo, compptr->ac_tbl_no, TRUE);
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
601METHODDEF(void)
602write_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
615METHODDEF(void)
616write_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
644GLOBAL(void)
645jinit_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}
665