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 file.
10 *
11 * This file contains routines to write JPEG datastream markers.
12 */
13
14#define JPEG_INTERNALS
15#include "jinclude.h"
16#include "jpeglib.h"
17#include "jpegcomp.h"
18
19
20typedef enum {			/* JPEG marker codes */
21  M_SOF0  = 0xc0,
22  M_SOF1  = 0xc1,
23  M_SOF2  = 0xc2,
24  M_SOF3  = 0xc3,
25
26  M_SOF5  = 0xc5,
27  M_SOF6  = 0xc6,
28  M_SOF7  = 0xc7,
29
30  M_JPG   = 0xc8,
31  M_SOF9  = 0xc9,
32  M_SOF10 = 0xca,
33  M_SOF11 = 0xcb,
34
35  M_SOF13 = 0xcd,
36  M_SOF14 = 0xce,
37  M_SOF15 = 0xcf,
38
39  M_DHT   = 0xc4,
40
41  M_DAC   = 0xcc,
42
43  M_RST0  = 0xd0,
44  M_RST1  = 0xd1,
45  M_RST2  = 0xd2,
46  M_RST3  = 0xd3,
47  M_RST4  = 0xd4,
48  M_RST5  = 0xd5,
49  M_RST6  = 0xd6,
50  M_RST7  = 0xd7,
51
52  M_SOI   = 0xd8,
53  M_EOI   = 0xd9,
54  M_SOS   = 0xda,
55  M_DQT   = 0xdb,
56  M_DNL   = 0xdc,
57  M_DRI   = 0xdd,
58  M_DHP   = 0xde,
59  M_EXP   = 0xdf,
60
61  M_APP0  = 0xe0,
62  M_APP1  = 0xe1,
63  M_APP2  = 0xe2,
64  M_APP3  = 0xe3,
65  M_APP4  = 0xe4,
66  M_APP5  = 0xe5,
67  M_APP6  = 0xe6,
68  M_APP7  = 0xe7,
69  M_APP8  = 0xe8,
70  M_APP9  = 0xe9,
71  M_APP10 = 0xea,
72  M_APP11 = 0xeb,
73  M_APP12 = 0xec,
74  M_APP13 = 0xed,
75  M_APP14 = 0xee,
76  M_APP15 = 0xef,
77
78  M_JPG0  = 0xf0,
79  M_JPG13 = 0xfd,
80  M_COM   = 0xfe,
81
82  M_TEM   = 0x01,
83
84  M_ERROR = 0x100
85} JPEG_MARKER;
86
87
88/* Private state */
89
90typedef struct {
91  struct jpeg_marker_writer pub; /* public fields */
92
93  unsigned int last_restart_interval; /* last DRI value emitted; 0 after SOI */
94} my_marker_writer;
95
96typedef my_marker_writer * my_marker_ptr;
97
98
99/*
100 * Basic output routines.
101 *
102 * Note that we do not support suspension while writing a marker.
103 * Therefore, an application using suspension must ensure that there is
104 * enough buffer space for the initial markers (typ. 600-700 bytes) before
105 * calling jpeg_start_compress, and enough space to write the trailing EOI
106 * (a few bytes) before calling jpeg_finish_compress.  Multipass compression
107 * modes are not supported at all with suspension, so those two are the only
108 * points where markers will be written.
109 */
110
111LOCAL(void)
112emit_byte (j_compress_ptr cinfo, int val)
113/* Emit a byte */
114{
115  struct jpeg_destination_mgr * dest = cinfo->dest;
116
117  *(dest->next_output_byte)++ = (JOCTET) val;
118  if (--dest->free_in_buffer == 0) {
119    if (! (*dest->empty_output_buffer) (cinfo))
120      ERREXIT(cinfo, JERR_CANT_SUSPEND);
121  }
122}
123
124
125LOCAL(void)
126emit_marker (j_compress_ptr cinfo, JPEG_MARKER mark)
127/* Emit a marker code */
128{
129  emit_byte(cinfo, 0xFF);
130  emit_byte(cinfo, (int) mark);
131}
132
133
134LOCAL(void)
135emit_2bytes (j_compress_ptr cinfo, int value)
136/* Emit a 2-byte integer; these are always MSB first in JPEG files */
137{
138  emit_byte(cinfo, (value >> 8) & 0xFF);
139  emit_byte(cinfo, value & 0xFF);
140}
141
142
143/*
144 * Routines to write specific marker types.
145 */
146
147LOCAL(int)
148emit_dqt (j_compress_ptr cinfo, int index)
149/* Emit a DQT marker */
150/* Returns the precision used (0 = 8bits, 1 = 16bits) for baseline checking */
151{
152  JQUANT_TBL * qtbl = cinfo->quant_tbl_ptrs[index];
153  int prec;
154  int i;
155
156  if (qtbl == NULL)
157    ERREXIT1(cinfo, JERR_NO_QUANT_TABLE, index);
158
159  prec = 0;
160  for (i = 0; i < DCTSIZE2; i++) {
161    if (qtbl->quantval[i] > 255)
162      prec = 1;
163  }
164
165  if (! qtbl->sent_table) {
166    emit_marker(cinfo, M_DQT);
167
168    emit_2bytes(cinfo, prec ? DCTSIZE2*2 + 1 + 2 : DCTSIZE2 + 1 + 2);
169
170    emit_byte(cinfo, index + (prec<<4));
171
172    for (i = 0; i < DCTSIZE2; i++) {
173      /* The table entries must be emitted in zigzag order. */
174      unsigned int qval = qtbl->quantval[jpeg_natural_order[i]];
175      if (prec)
176	emit_byte(cinfo, (int) (qval >> 8));
177      emit_byte(cinfo, (int) (qval & 0xFF));
178    }
179
180    qtbl->sent_table = TRUE;
181  }
182
183  return prec;
184}
185
186
187LOCAL(void)
188emit_dht (j_compress_ptr cinfo, int index, boolean is_ac)
189/* Emit a DHT marker */
190{
191  JHUFF_TBL * htbl;
192  int length, i;
193
194  if (is_ac) {
195    htbl = cinfo->ac_huff_tbl_ptrs[index];
196    index += 0x10;		/* output index has AC bit set */
197  } else {
198    htbl = cinfo->dc_huff_tbl_ptrs[index];
199  }
200
201  if (htbl == NULL)
202    ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, index);
203
204  if (! htbl->sent_table) {
205    emit_marker(cinfo, M_DHT);
206
207    length = 0;
208    for (i = 1; i <= 16; i++)
209      length += htbl->bits[i];
210
211    emit_2bytes(cinfo, length + 2 + 1 + 16);
212    emit_byte(cinfo, index);
213
214    for (i = 1; i <= 16; i++)
215      emit_byte(cinfo, htbl->bits[i]);
216
217    for (i = 0; i < length; i++)
218      emit_byte(cinfo, htbl->huffval[i]);
219
220    htbl->sent_table = TRUE;
221  }
222}
223
224
225LOCAL(void)
226emit_dac (j_compress_ptr cinfo)
227/* Emit a DAC marker */
228/* Since the useful info is so small, we want to emit all the tables in */
229/* one DAC marker.  Therefore this routine does its own scan of the table. */
230{
231#ifdef C_ARITH_CODING_SUPPORTED
232  char dc_in_use[NUM_ARITH_TBLS];
233  char ac_in_use[NUM_ARITH_TBLS];
234  int length, i;
235  jpeg_component_info *compptr;
236
237  for (i = 0; i < NUM_ARITH_TBLS; i++)
238    dc_in_use[i] = ac_in_use[i] = 0;
239
240  for (i = 0; i < cinfo->comps_in_scan; i++) {
241    compptr = cinfo->cur_comp_info[i];
242    /* DC needs no table for refinement scan */
243    if (cinfo->Ss == 0 && cinfo->Ah == 0)
244      dc_in_use[compptr->dc_tbl_no] = 1;
245    /* AC needs no table when not present */
246    if (cinfo->Se)
247      ac_in_use[compptr->ac_tbl_no] = 1;
248  }
249
250  length = 0;
251  for (i = 0; i < NUM_ARITH_TBLS; i++)
252    length += dc_in_use[i] + ac_in_use[i];
253
254  if (length) {
255    emit_marker(cinfo, M_DAC);
256
257    emit_2bytes(cinfo, length*2 + 2);
258
259    for (i = 0; i < NUM_ARITH_TBLS; i++) {
260      if (dc_in_use[i]) {
261	emit_byte(cinfo, i);
262	emit_byte(cinfo, cinfo->arith_dc_L[i] + (cinfo->arith_dc_U[i]<<4));
263      }
264      if (ac_in_use[i]) {
265	emit_byte(cinfo, i + 0x10);
266	emit_byte(cinfo, cinfo->arith_ac_K[i]);
267      }
268    }
269  }
270#endif /* C_ARITH_CODING_SUPPORTED */
271}
272
273
274LOCAL(void)
275emit_dri (j_compress_ptr cinfo)
276/* Emit a DRI marker */
277{
278  emit_marker(cinfo, M_DRI);
279
280  emit_2bytes(cinfo, 4);	/* fixed length */
281
282  emit_2bytes(cinfo, (int) cinfo->restart_interval);
283}
284
285
286LOCAL(void)
287emit_sof (j_compress_ptr cinfo, JPEG_MARKER code)
288/* Emit a SOF marker */
289{
290  int ci;
291  jpeg_component_info *compptr;
292
293  emit_marker(cinfo, code);
294
295  emit_2bytes(cinfo, 3 * cinfo->num_components + 2 + 5 + 1); /* length */
296
297  /* Make sure image isn't bigger than SOF field can handle */
298  if ((long) cinfo->_jpeg_height > 65535L ||
299      (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