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 ||
300 (long) cinfo->_jpeg_width > 65535L)
301 ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) 65535);
302
303 emit_byte(cinfo, cinfo->data_precision);
304 emit_2bytes(cinfo, (int) cinfo->_jpeg_height);
305 emit_2bytes(cinfo, (int) cinfo->_jpeg_width);
306
307 emit_byte(cinfo, cinfo->num_components);
308
309 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
310 ci++, compptr++) {
311 emit_byte(cinfo, compptr->component_id);
312 emit_byte(cinfo, (compptr->h_samp_factor << 4) + compptr->v_samp_factor);
313 emit_byte(cinfo, compptr->quant_tbl_no);
314 }
315}
316
317
318LOCAL(void)
319emit_sos (j_compress_ptr cinfo)
320/* Emit a SOS marker */
321{
322 int i, td, ta;
323 jpeg_component_info *compptr;
324
325 emit_marker(cinfo, M_SOS);
326
327 emit_2bytes(cinfo, 2 * cinfo->comps_in_scan + 2 + 1 + 3); /* length */
328
329 emit_byte(cinfo, cinfo->comps_in_scan);
330
331 for (i = 0; i < cinfo->comps_in_scan; i++) {
332 compptr = cinfo->cur_comp_info[i];
333 emit_byte(cinfo, compptr->component_id);
334
335 /* We emit 0 for unused field(s); this is recommended by the P&M text
336 * but does not seem to be specified in the standard.
337 */
338
339 /* DC needs no table for refinement scan */
340 td = cinfo->Ss == 0 && cinfo->Ah == 0 ? compptr->dc_tbl_no : 0;
341 /* AC needs no table when not present */
342 ta = cinfo->Se ? compptr->ac_tbl_no : 0;
343
344 emit_byte(cinfo, (td << 4) + ta);
345 }
346
347 emit_byte(cinfo, cinfo->Ss);
348 emit_byte(cinfo, cinfo->Se);
349 emit_byte(cinfo, (cinfo->Ah << 4) + cinfo->Al);
350}
351
352
353LOCAL(void)
354emit_jfif_app0 (j_compress_ptr cinfo)
355/* Emit a JFIF-compliant APP0 marker */
356{
357 /*
358 * Length of APP0 block (2 bytes)
359 * Block ID (4 bytes - ASCII "JFIF")
360 * Zero byte (1 byte to terminate the ID string)
361 * Version Major, Minor (2 bytes - major first)
362 * Units (1 byte - 0x00 = none, 0x01 = inch, 0x02 = cm)
363 * Xdpu (2 bytes - dots per unit horizontal)
364 * Ydpu (2 bytes - dots per unit vertical)
365 * Thumbnail X size (1 byte)
366 * Thumbnail Y size (1 byte)
367 */
368
369 emit_marker(cinfo, M_APP0);
370
371 emit_2bytes(cinfo, 2 + 4 + 1 + 2 + 1 + 2 + 2 + 1 + 1); /* length */
372
373 emit_byte(cinfo, 0x4A); /* Identifier: ASCII "JFIF" */
374 emit_byte(cinfo, 0x46);
375 emit_byte(cinfo, 0x49);
376 emit_byte(cinfo, 0x46);
377 emit_byte(cinfo, 0);
378 emit_byte(cinfo, cinfo->JFIF_major_version); /* Version fields */
379 emit_byte(cinfo, cinfo->JFIF_minor_version);
380 emit_byte(cinfo, cinfo->density_unit); /* Pixel size information */
381 emit_2bytes(cinfo, (int) cinfo->X_density);
382 emit_2bytes(cinfo, (int) cinfo->Y_density);
383 emit_byte(cinfo, 0); /* No thumbnail image */
384 emit_byte(cinfo, 0);
385}
386
387
388LOCAL(void)
389emit_adobe_app14 (j_compress_ptr cinfo)
390/* Emit an Adobe APP14 marker */
391{
392 /*
393 * Length of APP14 block (2 bytes)
394 * Block ID (5 bytes - ASCII "Adobe")
395 * Version Number (2 bytes - currently 100)
396 * Flags0 (2 bytes - currently 0)
397 * Flags1 (2 bytes - currently 0)
398 * Color transform (1 byte)
399 *
400 * Although Adobe TN 5116 mentions Version = 101, all the Adobe files
401 * now in circulation seem to use Version = 100, so that's what we write.
402 *
403 * We write the color transform byte as 1 if the JPEG color space is
404 * YCbCr, 2 if it's YCCK, 0 otherwise. Adobe's definition has to do with
405 * whether the encoder performed a transformation, which is pretty useless.
406 */
407
408 emit_marker(cinfo, M_APP14);
409
410 emit_2bytes(cinfo, 2 + 5 + 2 + 2 + 2 + 1); /* length */
411
412 emit_byte(cinfo, 0x41); /* Identifier: ASCII "Adobe" */
413 emit_byte(cinfo, 0x64);
414 emit_byte(cinfo, 0x6F);
415 emit_byte(cinfo, 0x62);
416 emit_byte(cinfo, 0x65);
417 emit_2bytes(cinfo, 100); /* Version */
418 emit_2bytes(cinfo, 0); /* Flags0 */
419 emit_2bytes(cinfo, 0); /* Flags1 */
420 switch (cinfo->jpeg_color_space) {
421 case JCS_YCbCr:
422 emit_byte(cinfo, 1); /* Color transform = 1 */
423 break;
424 case JCS_YCCK:
425 emit_byte(cinfo, 2); /* Color transform = 2 */
426 break;
427 default:
428 emit_byte(cinfo, 0); /* Color transform = 0 */
429 break;
430 }
431}
432
433
434/*
435 * These routines allow writing an arbitrary marker with parameters.
436 * The only intended use is to emit COM or APPn markers after calling
437 * write_file_header and before calling write_frame_header.
438 * Other uses are not guaranteed to produce desirable results.
439 * Counting the parameter bytes properly is the caller's responsibility.
440 */
441
442METHODDEF(void)
443write_marker_header (j_compress_ptr cinfo, int marker, unsigned int datalen)
444/* Emit an arbitrary marker header */
445{
446 if (datalen > (unsigned int) 65533) /* safety check */
447 ERREXIT(cinfo, JERR_BAD_LENGTH);
448
449 emit_marker(cinfo, (JPEG_MARKER) marker);
450
451 emit_2bytes(cinfo, (int) (datalen + 2)); /* total length */
452}
453
454METHODDEF(void)
455write_marker_byte (j_compress_ptr cinfo, int val)
456/* Emit one byte of marker parameters following write_marker_header */
457{
458 emit_byte(cinfo, val);
459}
460
461
462/*
463 * Write datastream header.
464 * This consists of an SOI and optional APPn markers.
465 * We recommend use of the JFIF marker, but not the Adobe marker,
466 * when using YCbCr or grayscale data. The JFIF marker should NOT
467 * be used for any other JPEG colorspace. The Adobe marker is helpful
468 * to distinguish RGB, CMYK, and YCCK colorspaces.
469 * Note that an application can write additional header markers after
470 * jpeg_start_compress returns.
471 */
472
473METHODDEF(void)
474write_file_header (j_compress_ptr cinfo)
475{
476 my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
477
478 emit_marker(cinfo, M_SOI); /* first the SOI */
479
480 /* SOI is defined to reset restart interval to 0 */
481 marker->last_restart_interval = 0;
482
483 if (cinfo->write_JFIF_header) /* next an optional JFIF APP0 */
484 emit_jfif_app0(cinfo);
485 if (cinfo->write_Adobe_marker) /* next an optional Adobe APP14 */
486 emit_adobe_app14(cinfo);
487}
488
489
490/*
491 * Write frame header.
492 * This consists of DQT and SOFn markers.
493 * Note that we do not emit the SOF until we have emitted the DQT(s).
494 * This avoids compatibility problems with incorrect implementations that
495 * try to error-check the quant table numbers as soon as they see the SOF.
496 */
497
498METHODDEF(void)
499write_frame_header (j_compress_ptr cinfo)
500{
501 int ci, prec;
502 boolean is_baseline;
503 jpeg_component_info *compptr;
504
505 /* Emit DQT for each quantization table.
506 * Note that emit_dqt() suppresses any duplicate tables.
507 */
508 prec = 0;
509 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
510 ci++, compptr++) {
511 prec += emit_dqt(cinfo, compptr->quant_tbl_no);
512 }
513 /* now prec is nonzero iff there are any 16-bit quant tables. */
514
515 /* Check for a non-baseline specification.
516 * Note we assume that Huffman table numbers won't be changed later.
517 */
518 if (cinfo->arith_code || cinfo->progressive_mode ||
519 cinfo->data_precision != 8) {
520 is_baseline = FALSE;
521 } else {
522 is_baseline = TRUE;
523 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
524 ci++, compptr++) {
525 if (compptr->dc_tbl_no > 1 || compptr->ac_tbl_no > 1)
526 is_baseline = FALSE;
527 }
528 if (prec && is_baseline) {
529 is_baseline = FALSE;
530 /* If it's baseline except for quantizer size, warn the user */
531 TRACEMS(cinfo, 0, JTRC_16BIT_TABLES);
532 }
533 }
534
535 /* Emit the proper SOF marker */
536 if (cinfo->arith_code) {
537 if (cinfo->progressive_mode)
538 emit_sof(cinfo, M_SOF10); /* SOF code for progressive arithmetic */
539 else
540 emit_sof(cinfo, M_SOF9); /* SOF code for sequential arithmetic */
541 } else {
542 if (cinfo->progressive_mode)
543 emit_sof(cinfo, M_SOF2); /* SOF code for progressive Huffman */
544 else if (is_baseline)
545 emit_sof(cinfo, M_SOF0); /* SOF code for baseline implementation */
546 else
547 emit_sof(cinfo, M_SOF1); /* SOF code for non-baseline Huffman file */
548 }
549}
550
551
552/*
553 * Write scan header.
554 * This consists of DHT or DAC markers, optional DRI, and SOS.
555 * Compressed data will be written following the SOS.
556 */
557
558METHODDEF(void)
559write_scan_header (j_compress_ptr cinfo)
560{
561 my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
562 int i;
563 jpeg_component_info *compptr;
564
565 if (cinfo->arith_code) {
566 /* Emit arith conditioning info. We may have some duplication
567 * if the file has multiple scans, but it's so small it's hardly
568 * worth worrying about.
569 */
570 emit_dac(cinfo);
571 } else {
572 /* Emit Huffman tables.
573 * Note that emit_dht() suppresses any duplicate tables.
574 */
575 for (i = 0; i < cinfo->comps_in_scan; i++) {
576 compptr = cinfo->cur_comp_info[i];
577 /* DC needs no table for refinement scan */
578 if (cinfo->Ss == 0 && cinfo->Ah == 0)
579 emit_dht(cinfo, compptr->dc_tbl_no, FALSE);
580 /* AC needs no table when not present */
581 if (cinfo->Se)
582 emit_dht(cinfo, compptr->ac_tbl_no, TRUE);
583 }
584 }
585
586 /* Emit DRI if required --- note that DRI value could change for each scan.
587 * We avoid wasting space with unnecessary DRIs, however.
588 */
589 if (cinfo->restart_interval != marker->last_restart_interval) {
590 emit_dri(cinfo);
591 marker->last_restart_interval = cinfo->restart_interval;
592 }
593
594 emit_sos(cinfo);
595}
596
597
598/*
599 * Write datastream trailer.
600 */
601
602METHODDEF(void)
603write_file_trailer (j_compress_ptr cinfo)
604{
605 emit_marker(cinfo, M_EOI);
606}
607
608
609/*
610 * Write an abbreviated table-specification datastream.
611 * This consists of SOI, DQT and DHT tables, and EOI.
612 * Any table that is defined and not marked sent_table = TRUE will be
613 * emitted. Note that all tables will be marked sent_table = TRUE at exit.
614 */
615
616METHODDEF(void)
617write_tables_only (j_compress_ptr cinfo)
618{
619 int i;
620
621 emit_marker(cinfo, M_SOI);
622
623 for (i = 0; i < NUM_QUANT_TBLS; i++) {
624 if (cinfo->quant_tbl_ptrs[i] != NULL)
625 (void) emit_dqt(cinfo, i);
626 }
627
628 if (! cinfo->arith_code) {
629 for (i = 0; i < NUM_HUFF_TBLS; i++) {
630 if (cinfo->dc_huff_tbl_ptrs[i] != NULL)
631 emit_dht(cinfo, i, FALSE);
632 if (cinfo->ac_huff_tbl_ptrs[i] != NULL)
633 emit_dht(cinfo, i, TRUE);
634 }
635 }
636
637 emit_marker(cinfo, M_EOI);
638}
639
640
641/*
642 * Initialize the marker writer module.
643 */
644
645GLOBAL(void)
646jinit_marker_writer (j_compress_ptr cinfo)
647{
648 my_marker_ptr marker;
649
650 /* Create the subobject */
651 marker = (my_marker_ptr)
652 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
653 sizeof(my_marker_writer));
654 cinfo->marker = (struct jpeg_marker_writer *) marker;
655 /* Initialize method pointers */
656 marker->pub.write_file_header = write_file_header;
657 marker->pub.write_frame_header = write_frame_header;
658 marker->pub.write_scan_header = write_scan_header;
659 marker->pub.write_file_trailer = write_file_trailer;
660 marker->pub.write_tables_only = write_tables_only;
661 marker->pub.write_marker_header = write_marker_header;
662 marker->pub.write_marker_byte = write_marker_byte;
663 /* Initialize private state */
664 marker->last_restart_interval = 0;
665}
666