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
21 typedef 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
91 typedef 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
97 typedef 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
112 LOCAL(void)
emit_byte(j_compress_ptr cinfo,int val)113 emit_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
126 LOCAL(void)
emit_marker(j_compress_ptr cinfo,JPEG_MARKER mark)127 emit_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
135 LOCAL(void)
emit_2bytes(j_compress_ptr cinfo,int value)136 emit_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
148 LOCAL(int)
emit_dqt(j_compress_ptr cinfo,int index)149 emit_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 LOCAL(int)
emit_multi_dqt(j_compress_ptr cinfo)188 emit_multi_dqt (j_compress_ptr cinfo)
189 /* Emits a DQT marker containing all quantization tables */
190 /* Returns number of emitted 16-bit tables, or -1 for failed for baseline checking. */
191 {
192 int prec[MAX_COMPONENTS];
193 int seen[MAX_COMPONENTS] = { 0 };
194 int fin_prec = 0;
195 int ci;
196 int size = 0;
197
198 if (cinfo->master->compress_profile == JCP_FASTEST)
199 return -1;
200
201 for (ci = 0; ci < cinfo->num_components; ci++) {
202 int tbl_num = cinfo->comp_info[ci].quant_tbl_no;
203 int i;
204 JQUANT_TBL * qtbl = cinfo->quant_tbl_ptrs[tbl_num];
205
206 if (qtbl == NULL || qtbl->sent_table == TRUE)
207 return -1;
208
209 prec[ci] = 0;
210 for (i = 0; i < DCTSIZE2; i++)
211 prec[ci] = !!(prec[ci] + (qtbl->quantval[i] > 255));
212
213 fin_prec += prec[ci];
214 }
215
216 emit_marker(cinfo, M_DQT);
217
218 for (ci = 0; ci < cinfo->num_components; ci++) {
219 int tbl_num = cinfo->comp_info[ci].quant_tbl_no;
220
221 if (!seen[tbl_num]) {
222 size += DCTSIZE2 * (prec[ci] + 1) + 1;
223 seen[tbl_num] = 1;
224 }
225 }
226 size += 2;
227
228 emit_2bytes(cinfo, size);
229
230 for (ci = 0; ci < cinfo->num_components; ci++) {
231 int tbl_num = cinfo->comp_info[ci].quant_tbl_no;
232 int i;
233 JQUANT_TBL * qtbl = cinfo->quant_tbl_ptrs[tbl_num];
234
235 if (qtbl->sent_table == TRUE)
236 continue;
237
238 emit_byte(cinfo, tbl_num + (prec[ci] << 4));
239
240 for (i = 0; i < DCTSIZE2; i++) {
241 unsigned int qval = qtbl->quantval[jpeg_natural_order[i]];
242
243 if (prec[ci])
244 emit_byte(cinfo, (int) (qval >> 8));
245 emit_byte(cinfo, (int) (qval & 0xFF));
246 }
247
248 qtbl->sent_table = TRUE;
249 }
250
251 return fin_prec;
252 }
253
254 LOCAL(void)
emit_dht(j_compress_ptr cinfo,int index,boolean is_ac)255 emit_dht(j_compress_ptr cinfo, int index, boolean is_ac)
256 /* Emit a DHT marker */
257 {
258 JHUFF_TBL *htbl;
259 int length, i;
260
261 if (is_ac) {
262 htbl = cinfo->ac_huff_tbl_ptrs[index];
263 index += 0x10; /* output index has AC bit set */
264 } else {
265 htbl = cinfo->dc_huff_tbl_ptrs[index];
266 }
267
268 if (htbl == NULL)
269 ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, index);
270
271 if (!htbl->sent_table) {
272 emit_marker(cinfo, M_DHT);
273
274 length = 0;
275 for (i = 1; i <= 16; i++)
276 length += htbl->bits[i];
277
278 emit_2bytes(cinfo, length + 2 + 1 + 16);
279 emit_byte(cinfo, index);
280
281 for (i = 1; i <= 16; i++)
282 emit_byte(cinfo, htbl->bits[i]);
283
284 for (i = 0; i < length; i++)
285 emit_byte(cinfo, htbl->huffval[i]);
286
287 htbl->sent_table = TRUE;
288 }
289 }
290
291 LOCAL(boolean)
emit_multi_dht(j_compress_ptr cinfo)292 emit_multi_dht (j_compress_ptr cinfo)
293 /* Emit all DHT markers */
294 /* Returns FALSE on failure, TRUE otherwise. */
295 {
296 int i, j;
297 int length = 2;
298 int dclens[NUM_HUFF_TBLS] = { 0 };
299 int aclens[NUM_HUFF_TBLS] = { 0 };
300 JHUFF_TBL *dcseen[NUM_HUFF_TBLS] = { NULL };
301 JHUFF_TBL *acseen[NUM_HUFF_TBLS] = { NULL };
302
303 if (cinfo->master->compress_profile == JCP_FASTEST)
304 return 0;
305
306 /* Calclate the total length. */
307 for (i = 0; i < cinfo->comps_in_scan; i++) {
308 jpeg_component_info *compptr = cinfo->cur_comp_info[i];
309 int dcidx = compptr->dc_tbl_no;
310 int acidx = compptr->ac_tbl_no;
311 JHUFF_TBL *dctbl = cinfo->dc_huff_tbl_ptrs[dcidx];
312 JHUFF_TBL *actbl = cinfo->ac_huff_tbl_ptrs[acidx];
313 int seen = 0;
314
315 /* Handle DC table lenghts */
316 if (cinfo->Ss == 0 && cinfo->Ah == 0) {
317 if (dctbl == NULL)
318 ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, dcidx);
319
320 if (dctbl->sent_table)
321 continue;
322
323 for (j = 0; j < NUM_HUFF_TBLS; j++)
324 seen += (dctbl == dcseen[j]);
325 if (seen)
326 continue;
327 dcseen[i] = dctbl;
328
329 for (j = 1; j <= 16; j++)
330 dclens[i] += dctbl->bits[j];
331 length += dclens[i] + 16 + 1;
332 }
333
334 /* Handle AC table lengths */
335 if (cinfo->Se) {
336 if (actbl == NULL)
337 ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, acidx + 0x10);
338
339 if (actbl->sent_table)
340 continue;
341
342 seen = 0;
343 for (j = 0; j < NUM_HUFF_TBLS; j++)
344 seen += (actbl == acseen[j]);
345 if (seen)
346 continue;
347 acseen[i] = actbl;
348
349 for (j = 1; j <= 16; j++)
350 aclens[i] += actbl->bits[j];
351 length += aclens[i] + 16 + 1;
352
353 }
354 }
355
356 /* Make sure we can fit it all into one DHT marker */
357 if (length > (1 << 16) - 1)
358 return FALSE;
359
360 emit_marker(cinfo, M_DHT);
361 emit_2bytes(cinfo, length);
362
363 for (i = 0; i < cinfo->comps_in_scan; i++) {
364 jpeg_component_info *compptr = cinfo->cur_comp_info[i];
365 int dcidx = compptr->dc_tbl_no;
366 int acidx = compptr->ac_tbl_no;
367 JHUFF_TBL *dctbl = cinfo->dc_huff_tbl_ptrs[dcidx];
368 JHUFF_TBL *actbl = cinfo->ac_huff_tbl_ptrs[acidx];
369
370 acidx += 0x10;
371
372 /* DC */
373 if (cinfo->Ss == 0 && cinfo->Ah == 0 && !dctbl->sent_table) {
374 emit_byte(cinfo, dcidx);
375
376 for (j = 1; j <= 16; j++)
377 emit_byte(cinfo, dctbl->bits[j]);
378
379 for (j = 0; j < dclens[i]; j++)
380 emit_byte(cinfo, dctbl->huffval[j]);
381
382 dctbl->sent_table = TRUE;
383 }
384
385 if (cinfo->Se && !actbl->sent_table) {
386 emit_byte(cinfo, acidx);
387
388 for (j = 1; j <= 16; j++)
389 emit_byte(cinfo, actbl->bits[j]);
390
391 for (j = 0; j < aclens[i]; j++)
392 emit_byte(cinfo, actbl->huffval[j]);
393
394 actbl->sent_table = TRUE;
395 }
396 }
397
398 return TRUE;
399 }
400
401 LOCAL(void)
emit_dac(j_compress_ptr cinfo)402 emit_dac(j_compress_ptr cinfo)
403 /* Emit a DAC marker */
404 /* Since the useful info is so small, we want to emit all the tables in */
405 /* one DAC marker. Therefore this routine does its own scan of the table. */
406 {
407 #ifdef C_ARITH_CODING_SUPPORTED
408 char dc_in_use[NUM_ARITH_TBLS];
409 char ac_in_use[NUM_ARITH_TBLS];
410 int length, i;
411 jpeg_component_info *compptr;
412
413 for (i = 0; i < NUM_ARITH_TBLS; i++)
414 dc_in_use[i] = ac_in_use[i] = 0;
415
416 for (i = 0; i < cinfo->comps_in_scan; i++) {
417 compptr = cinfo->cur_comp_info[i];
418 /* DC needs no table for refinement scan */
419 if (cinfo->Ss == 0 && cinfo->Ah == 0)
420 dc_in_use[compptr->dc_tbl_no] = 1;
421 /* AC needs no table when not present */
422 if (cinfo->Se)
423 ac_in_use[compptr->ac_tbl_no] = 1;
424 }
425
426 length = 0;
427 for (i = 0; i < NUM_ARITH_TBLS; i++)
428 length += dc_in_use[i] + ac_in_use[i];
429
430 if (length) {
431 emit_marker(cinfo, M_DAC);
432
433 emit_2bytes(cinfo, length * 2 + 2);
434
435 for (i = 0; i < NUM_ARITH_TBLS; i++) {
436 if (dc_in_use[i]) {
437 emit_byte(cinfo, i);
438 emit_byte(cinfo, cinfo->arith_dc_L[i] + (cinfo->arith_dc_U[i] << 4));
439 }
440 if (ac_in_use[i]) {
441 emit_byte(cinfo, i + 0x10);
442 emit_byte(cinfo, cinfo->arith_ac_K[i]);
443 }
444 }
445 }
446 #endif /* C_ARITH_CODING_SUPPORTED */
447 }
448
449
450 LOCAL(void)
emit_dri(j_compress_ptr cinfo)451 emit_dri(j_compress_ptr cinfo)
452 /* Emit a DRI marker */
453 {
454 emit_marker(cinfo, M_DRI);
455
456 emit_2bytes(cinfo, 4); /* fixed length */
457
458 emit_2bytes(cinfo, (int)cinfo->restart_interval);
459 }
460
461
462 LOCAL(void)
emit_sof(j_compress_ptr cinfo,JPEG_MARKER code)463 emit_sof(j_compress_ptr cinfo, JPEG_MARKER code)
464 /* Emit a SOF marker */
465 {
466 int ci;
467 jpeg_component_info *compptr;
468
469 emit_marker(cinfo, code);
470
471 emit_2bytes(cinfo, 3 * cinfo->num_components + 2 + 5 + 1); /* length */
472
473 /* Make sure image isn't bigger than SOF field can handle */
474 if ((long)cinfo->_jpeg_height > 65535L || (long)cinfo->_jpeg_width > 65535L)
475 ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int)65535);
476
477 emit_byte(cinfo, cinfo->data_precision);
478 emit_2bytes(cinfo, (int)cinfo->_jpeg_height);
479 emit_2bytes(cinfo, (int)cinfo->_jpeg_width);
480
481 emit_byte(cinfo, cinfo->num_components);
482
483 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
484 ci++, compptr++) {
485 emit_byte(cinfo, compptr->component_id);
486 emit_byte(cinfo, (compptr->h_samp_factor << 4) + compptr->v_samp_factor);
487 emit_byte(cinfo, compptr->quant_tbl_no);
488 }
489 }
490
491
492 LOCAL(void)
emit_sos(j_compress_ptr cinfo)493 emit_sos(j_compress_ptr cinfo)
494 /* Emit a SOS marker */
495 {
496 int i, td, ta;
497 jpeg_component_info *compptr;
498
499 emit_marker(cinfo, M_SOS);
500
501 emit_2bytes(cinfo, 2 * cinfo->comps_in_scan + 2 + 1 + 3); /* length */
502
503 emit_byte(cinfo, cinfo->comps_in_scan);
504
505 for (i = 0; i < cinfo->comps_in_scan; i++) {
506 compptr = cinfo->cur_comp_info[i];
507 emit_byte(cinfo, compptr->component_id);
508
509 /* We emit 0 for unused field(s); this is recommended by the P&M text
510 * but does not seem to be specified in the standard.
511 */
512
513 /* DC needs no table for refinement scan */
514 td = cinfo->Ss == 0 && cinfo->Ah == 0 ? compptr->dc_tbl_no : 0;
515 /* AC needs no table when not present */
516 ta = cinfo->Se ? compptr->ac_tbl_no : 0;
517
518 emit_byte(cinfo, (td << 4) + ta);
519 }
520
521 emit_byte(cinfo, cinfo->Ss);
522 emit_byte(cinfo, cinfo->Se);
523 emit_byte(cinfo, (cinfo->Ah << 4) + cinfo->Al);
524 }
525
526
527 LOCAL(void)
emit_jfif_app0(j_compress_ptr cinfo)528 emit_jfif_app0(j_compress_ptr cinfo)
529 /* Emit a JFIF-compliant APP0 marker */
530 {
531 /*
532 * Length of APP0 block (2 bytes)
533 * Block ID (4 bytes - ASCII "JFIF")
534 * Zero byte (1 byte to terminate the ID string)
535 * Version Major, Minor (2 bytes - major first)
536 * Units (1 byte - 0x00 = none, 0x01 = inch, 0x02 = cm)
537 * Xdpu (2 bytes - dots per unit horizontal)
538 * Ydpu (2 bytes - dots per unit vertical)
539 * Thumbnail X size (1 byte)
540 * Thumbnail Y size (1 byte)
541 */
542
543 emit_marker(cinfo, M_APP0);
544
545 emit_2bytes(cinfo, 2 + 4 + 1 + 2 + 1 + 2 + 2 + 1 + 1); /* length */
546
547 emit_byte(cinfo, 0x4A); /* Identifier: ASCII "JFIF" */
548 emit_byte(cinfo, 0x46);
549 emit_byte(cinfo, 0x49);
550 emit_byte(cinfo, 0x46);
551 emit_byte(cinfo, 0);
552 emit_byte(cinfo, cinfo->JFIF_major_version); /* Version fields */
553 emit_byte(cinfo, cinfo->JFIF_minor_version);
554 emit_byte(cinfo, cinfo->density_unit); /* Pixel size information */
555 emit_2bytes(cinfo, (int)cinfo->X_density);
556 emit_2bytes(cinfo, (int)cinfo->Y_density);
557 emit_byte(cinfo, 0); /* No thumbnail image */
558 emit_byte(cinfo, 0);
559 }
560
561
562 LOCAL(void)
emit_adobe_app14(j_compress_ptr cinfo)563 emit_adobe_app14(j_compress_ptr cinfo)
564 /* Emit an Adobe APP14 marker */
565 {
566 /*
567 * Length of APP14 block (2 bytes)
568 * Block ID (5 bytes - ASCII "Adobe")
569 * Version Number (2 bytes - currently 100)
570 * Flags0 (2 bytes - currently 0)
571 * Flags1 (2 bytes - currently 0)
572 * Color transform (1 byte)
573 *
574 * Although Adobe TN 5116 mentions Version = 101, all the Adobe files
575 * now in circulation seem to use Version = 100, so that's what we write.
576 *
577 * We write the color transform byte as 1 if the JPEG color space is
578 * YCbCr, 2 if it's YCCK, 0 otherwise. Adobe's definition has to do with
579 * whether the encoder performed a transformation, which is pretty useless.
580 */
581
582 emit_marker(cinfo, M_APP14);
583
584 emit_2bytes(cinfo, 2 + 5 + 2 + 2 + 2 + 1); /* length */
585
586 emit_byte(cinfo, 0x41); /* Identifier: ASCII "Adobe" */
587 emit_byte(cinfo, 0x64);
588 emit_byte(cinfo, 0x6F);
589 emit_byte(cinfo, 0x62);
590 emit_byte(cinfo, 0x65);
591 emit_2bytes(cinfo, 100); /* Version */
592 emit_2bytes(cinfo, 0); /* Flags0 */
593 emit_2bytes(cinfo, 0); /* Flags1 */
594 switch (cinfo->jpeg_color_space) {
595 case JCS_YCbCr:
596 emit_byte(cinfo, 1); /* Color transform = 1 */
597 break;
598 case JCS_YCCK:
599 emit_byte(cinfo, 2); /* Color transform = 2 */
600 break;
601 default:
602 emit_byte(cinfo, 0); /* Color transform = 0 */
603 break;
604 }
605 }
606
607
608 /*
609 * These routines allow writing an arbitrary marker with parameters.
610 * The only intended use is to emit COM or APPn markers after calling
611 * write_file_header and before calling write_frame_header.
612 * Other uses are not guaranteed to produce desirable results.
613 * Counting the parameter bytes properly is the caller's responsibility.
614 */
615
616 METHODDEF(void)
write_marker_header(j_compress_ptr cinfo,int marker,unsigned int datalen)617 write_marker_header(j_compress_ptr cinfo, int marker, unsigned int datalen)
618 /* Emit an arbitrary marker header */
619 {
620 if (datalen > (unsigned int)65533) /* safety check */
621 ERREXIT(cinfo, JERR_BAD_LENGTH);
622
623 emit_marker(cinfo, (JPEG_MARKER)marker);
624
625 emit_2bytes(cinfo, (int)(datalen + 2)); /* total length */
626 }
627
628 METHODDEF(void)
write_marker_byte(j_compress_ptr cinfo,int val)629 write_marker_byte(j_compress_ptr cinfo, int val)
630 /* Emit one byte of marker parameters following write_marker_header */
631 {
632 emit_byte(cinfo, val);
633 }
634
635
636 /*
637 * Write datastream header.
638 * This consists of an SOI and optional APPn markers.
639 * We recommend use of the JFIF marker, but not the Adobe marker,
640 * when using YCbCr or grayscale data. The JFIF marker should NOT
641 * be used for any other JPEG colorspace. The Adobe marker is helpful
642 * to distinguish RGB, CMYK, and YCCK colorspaces.
643 * Note that an application can write additional header markers after
644 * jpeg_start_compress returns.
645 */
646
647 METHODDEF(void)
write_file_header(j_compress_ptr cinfo)648 write_file_header(j_compress_ptr cinfo)
649 {
650 my_marker_ptr marker = (my_marker_ptr)cinfo->marker;
651
652 emit_marker(cinfo, M_SOI); /* first the SOI */
653
654 /* SOI is defined to reset restart interval to 0 */
655 marker->last_restart_interval = 0;
656
657 if (cinfo->write_JFIF_header) /* next an optional JFIF APP0 */
658 emit_jfif_app0(cinfo);
659 if (cinfo->write_Adobe_marker) /* next an optional Adobe APP14 */
660 emit_adobe_app14(cinfo);
661 }
662
663
664 /*
665 * Write frame header.
666 * This consists of DQT and SOFn markers.
667 * Note that we do not emit the SOF until we have emitted the DQT(s).
668 * This avoids compatibility problems with incorrect implementations that
669 * try to error-check the quant table numbers as soon as they see the SOF.
670 */
671
672 METHODDEF(void)
write_frame_header(j_compress_ptr cinfo)673 write_frame_header(j_compress_ptr cinfo)
674 {
675 int ci, prec;
676 boolean is_baseline;
677 jpeg_component_info *compptr;
678
679 /* Emit DQT for each quantization table.
680 * Note that emit_dqt() suppresses any duplicate tables.
681 */
682 prec = emit_multi_dqt(cinfo);
683 if (prec == -1) {
684 prec = 0;
685 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
686 ci++, compptr++) {
687 prec += emit_dqt(cinfo, compptr->quant_tbl_no);
688 }
689 }
690 /* now prec is nonzero iff there are any 16-bit quant tables. */
691
692 /* Check for a non-baseline specification.
693 * Note we assume that Huffman table numbers won't be changed later.
694 */
695 if (cinfo->arith_code || cinfo->progressive_mode ||
696 cinfo->data_precision != 8) {
697 is_baseline = FALSE;
698 } else {
699 is_baseline = TRUE;
700 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
701 ci++, compptr++) {
702 if (compptr->dc_tbl_no > 1 || compptr->ac_tbl_no > 1)
703 is_baseline = FALSE;
704 }
705 if (prec && is_baseline) {
706 is_baseline = FALSE;
707 /* If it's baseline except for quantizer size, warn the user */
708 TRACEMS(cinfo, 0, JTRC_16BIT_TABLES);
709 }
710 }
711
712 /* Emit the proper SOF marker */
713 if (cinfo->arith_code) {
714 if (cinfo->progressive_mode)
715 emit_sof(cinfo, M_SOF10); /* SOF code for progressive arithmetic */
716 else
717 emit_sof(cinfo, M_SOF9); /* SOF code for sequential arithmetic */
718 } else {
719 if (cinfo->progressive_mode)
720 emit_sof(cinfo, M_SOF2); /* SOF code for progressive Huffman */
721 else if (is_baseline)
722 emit_sof(cinfo, M_SOF0); /* SOF code for baseline implementation */
723 else
724 emit_sof(cinfo, M_SOF1); /* SOF code for non-baseline Huffman file */
725 }
726 }
727
728
729 /*
730 * Write scan header.
731 * This consists of DHT or DAC markers, optional DRI, and SOS.
732 * Compressed data will be written following the SOS.
733 */
734
735 METHODDEF(void)
write_scan_header(j_compress_ptr cinfo)736 write_scan_header(j_compress_ptr cinfo)
737 {
738 my_marker_ptr marker = (my_marker_ptr)cinfo->marker;
739 int i;
740 jpeg_component_info *compptr;
741
742 if (cinfo->arith_code) {
743 /* Emit arith conditioning info. We may have some duplication
744 * if the file has multiple scans, but it's so small it's hardly
745 * worth worrying about.
746 */
747 emit_dac(cinfo);
748 } else {
749 /* Emit Huffman tables.
750 * Note that emit_dht() suppresses any duplicate tables.
751 */
752 if (!emit_multi_dht(cinfo)) {
753 for (i = 0; i < cinfo->comps_in_scan; i++) {
754 compptr = cinfo->cur_comp_info[i];
755 /* DC needs no table for refinement scan */
756 if (cinfo->Ss == 0 && cinfo->Ah == 0)
757 emit_dht(cinfo, compptr->dc_tbl_no, FALSE);
758 /* AC needs no table when not present */
759 if (cinfo->Se)
760 emit_dht(cinfo, compptr->ac_tbl_no, TRUE);
761 }
762 }
763 }
764
765 /* Emit DRI if required --- note that DRI value could change for each scan.
766 * We avoid wasting space with unnecessary DRIs, however.
767 */
768 if (cinfo->restart_interval != marker->last_restart_interval) {
769 emit_dri(cinfo);
770 marker->last_restart_interval = cinfo->restart_interval;
771 }
772
773 emit_sos(cinfo);
774 }
775
776
777 /*
778 * Write datastream trailer.
779 */
780
781 METHODDEF(void)
write_file_trailer(j_compress_ptr cinfo)782 write_file_trailer(j_compress_ptr cinfo)
783 {
784 emit_marker(cinfo, M_EOI);
785 }
786
787
788 /*
789 * Write an abbreviated table-specification datastream.
790 * This consists of SOI, DQT and DHT tables, and EOI.
791 * Any table that is defined and not marked sent_table = TRUE will be
792 * emitted. Note that all tables will be marked sent_table = TRUE at exit.
793 */
794
795 METHODDEF(void)
write_tables_only(j_compress_ptr cinfo)796 write_tables_only(j_compress_ptr cinfo)
797 {
798 int i;
799
800 emit_marker(cinfo, M_SOI);
801
802 for (i = 0; i < NUM_QUANT_TBLS; i++) {
803 if (cinfo->quant_tbl_ptrs[i] != NULL)
804 (void)emit_dqt(cinfo, i);
805 }
806
807 if (!cinfo->arith_code) {
808 for (i = 0; i < NUM_HUFF_TBLS; i++) {
809 if (cinfo->dc_huff_tbl_ptrs[i] != NULL)
810 emit_dht(cinfo, i, FALSE);
811 if (cinfo->ac_huff_tbl_ptrs[i] != NULL)
812 emit_dht(cinfo, i, TRUE);
813 }
814 }
815
816 emit_marker(cinfo, M_EOI);
817 }
818
819
820 /*
821 * Initialize the marker writer module.
822 */
823
824 GLOBAL(void)
jinit_marker_writer(j_compress_ptr cinfo)825 jinit_marker_writer(j_compress_ptr cinfo)
826 {
827 my_marker_ptr marker;
828
829 /* Create the subobject */
830 marker = (my_marker_ptr)
831 (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
832 sizeof(my_marker_writer));
833 cinfo->marker = (struct jpeg_marker_writer *)marker;
834 /* Initialize method pointers */
835 marker->pub.write_file_header = write_file_header;
836 marker->pub.write_frame_header = write_frame_header;
837 marker->pub.write_scan_header = write_scan_header;
838 marker->pub.write_file_trailer = write_file_trailer;
839 marker->pub.write_tables_only = write_tables_only;
840 marker->pub.write_marker_header = write_marker_header;
841 marker->pub.write_marker_byte = write_marker_byte;
842 /* Initialize private state */
843 marker->last_restart_interval = 0;
844 }
845