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