1 #if !defined(_FX_JPEG_TURBO_)
2 /*
3  * jcmarker.c
4  *
5  * Copyright (C) 1991-1998, Thomas G. Lane.
6  * This file is part of the Independent JPEG Group's software.
7  * For conditions of distribution and use, see the accompanying README file.
8  *
9  * This file contains routines to write JPEG datastream markers.
10  */
11 
12 #define JPEG_INTERNALS
13 #include "jinclude.h"
14 #include "jpeglib.h"
15 
16 
17 typedef enum {			/* JPEG marker codes */
18   M_SOF0  = 0xc0,
19   M_SOF1  = 0xc1,
20   M_SOF2  = 0xc2,
21   M_SOF3  = 0xc3,
22 
23   M_SOF5  = 0xc5,
24   M_SOF6  = 0xc6,
25   M_SOF7  = 0xc7,
26 
27   M_JPG   = 0xc8,
28   M_SOF9  = 0xc9,
29   M_SOF10 = 0xca,
30   M_SOF11 = 0xcb,
31 
32   M_SOF13 = 0xcd,
33   M_SOF14 = 0xce,
34   M_SOF15 = 0xcf,
35 
36   M_DHT   = 0xc4,
37 
38   M_DAC   = 0xcc,
39 
40   M_RST0  = 0xd0,
41   M_RST1  = 0xd1,
42   M_RST2  = 0xd2,
43   M_RST3  = 0xd3,
44   M_RST4  = 0xd4,
45   M_RST5  = 0xd5,
46   M_RST6  = 0xd6,
47   M_RST7  = 0xd7,
48 
49   M_SOI   = 0xd8,
50   M_EOI   = 0xd9,
51   M_SOS   = 0xda,
52   M_DQT   = 0xdb,
53   M_DNL   = 0xdc,
54   M_DRI   = 0xdd,
55   M_DHP   = 0xde,
56   M_EXP   = 0xdf,
57 
58   M_APP0  = 0xe0,
59   M_APP1  = 0xe1,
60   M_APP2  = 0xe2,
61   M_APP3  = 0xe3,
62   M_APP4  = 0xe4,
63   M_APP5  = 0xe5,
64   M_APP6  = 0xe6,
65   M_APP7  = 0xe7,
66   M_APP8  = 0xe8,
67   M_APP9  = 0xe9,
68   M_APP10 = 0xea,
69   M_APP11 = 0xeb,
70   M_APP12 = 0xec,
71   M_APP13 = 0xed,
72   M_APP14 = 0xee,
73   M_APP15 = 0xef,
74 
75   M_JPG0  = 0xf0,
76   M_JPG13 = 0xfd,
77   M_COM   = 0xfe,
78 
79   M_TEM   = 0x01,
80 
81   M_ERROR = 0x100
82 } JPEG_MARKER;
83 
84 
85 /* Private state */
86 
87 typedef struct {
88   struct jpeg_marker_writer pub; /* public fields */
89 
90   unsigned int last_restart_interval; /* last DRI value emitted; 0 after SOI */
91 } my_marker_writer;
92 
93 typedef my_marker_writer * my_marker_ptr;
94 
95 
96 /*
97  * Basic output routines.
98  *
99  * Note that we do not support suspension while writing a marker.
100  * Therefore, an application using suspension must ensure that there is
101  * enough buffer space for the initial markers (typ. 600-700 bytes) before
102  * calling jpeg_start_compress, and enough space to write the trailing EOI
103  * (a few bytes) before calling jpeg_finish_compress.  Multipass compression
104  * modes are not supported at all with suspension, so those two are the only
105  * points where markers will be written.
106  */
107 
108 LOCAL(void)
emit_byte(j_compress_ptr cinfo,int val)109 emit_byte (j_compress_ptr cinfo, int val)
110 /* Emit a byte */
111 {
112   struct jpeg_destination_mgr * dest = cinfo->dest;
113 
114   *(dest->next_output_byte)++ = (JOCTET) val;
115   if (--dest->free_in_buffer == 0) {
116     if (! (*dest->empty_output_buffer) (cinfo))
117       ERREXIT(cinfo, JERR_CANT_SUSPEND);
118   }
119 }
120 
121 
122 LOCAL(void)
emit_marker(j_compress_ptr cinfo,JPEG_MARKER mark)123 emit_marker (j_compress_ptr cinfo, JPEG_MARKER mark)
124 /* Emit a marker code */
125 {
126   emit_byte(cinfo, 0xFF);
127   emit_byte(cinfo, (int) mark);
128 }
129 
130 
131 LOCAL(void)
emit_2bytes(j_compress_ptr cinfo,int value)132 emit_2bytes (j_compress_ptr cinfo, int value)
133 /* Emit a 2-byte integer; these are always MSB first in JPEG files */
134 {
135   emit_byte(cinfo, (value >> 8) & 0xFF);
136   emit_byte(cinfo, value & 0xFF);
137 }
138 
139 
140 /*
141  * Routines to write specific marker types.
142  */
143 
144 LOCAL(int)
emit_dqt(j_compress_ptr cinfo,int index)145 emit_dqt (j_compress_ptr cinfo, int index)
146 /* Emit a DQT marker */
147 /* Returns the precision used (0 = 8bits, 1 = 16bits) for baseline checking */
148 {
149   JQUANT_TBL * qtbl = cinfo->quant_tbl_ptrs[index];
150   int prec;
151   int i;
152 
153   if (qtbl == NULL)
154     ERREXIT1(cinfo, JERR_NO_QUANT_TABLE, index);
155 
156   prec = 0;
157   for (i = 0; i < DCTSIZE2; i++) {
158     if (qtbl->quantval[i] > 255)
159       prec = 1;
160   }
161 
162   if (! qtbl->sent_table) {
163     emit_marker(cinfo, M_DQT);
164 
165     emit_2bytes(cinfo, prec ? DCTSIZE2*2 + 1 + 2 : DCTSIZE2 + 1 + 2);
166 
167     emit_byte(cinfo, index + (prec<<4));
168 
169     for (i = 0; i < DCTSIZE2; i++) {
170       /* The table entries must be emitted in zigzag order. */
171       unsigned int qval = qtbl->quantval[jpeg_natural_order[i]];
172       if (prec)
173 	emit_byte(cinfo, (int) (qval >> 8));
174       emit_byte(cinfo, (int) (qval & 0xFF));
175     }
176 
177     qtbl->sent_table = TRUE;
178   }
179 
180   return prec;
181 }
182 
183 
184 LOCAL(void)
emit_dht(j_compress_ptr cinfo,int index,boolean is_ac)185 emit_dht (j_compress_ptr cinfo, int index, boolean is_ac)
186 /* Emit a DHT marker */
187 {
188   JHUFF_TBL * htbl;
189   int length, i;
190 
191   if (is_ac) {
192     htbl = cinfo->ac_huff_tbl_ptrs[index];
193     index += 0x10;		/* output index has AC bit set */
194   } else {
195     htbl = cinfo->dc_huff_tbl_ptrs[index];
196   }
197 
198   if (htbl == NULL)
199     ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, index);
200 
201   if (! htbl->sent_table) {
202     emit_marker(cinfo, M_DHT);
203 
204     length = 0;
205     for (i = 1; i <= 16; i++)
206       length += htbl->bits[i];
207 
208     emit_2bytes(cinfo, length + 2 + 1 + 16);
209     emit_byte(cinfo, index);
210 
211     for (i = 1; i <= 16; i++)
212       emit_byte(cinfo, htbl->bits[i]);
213 
214     for (i = 0; i < length; i++)
215       emit_byte(cinfo, htbl->huffval[i]);
216 
217     htbl->sent_table = TRUE;
218   }
219 }
220 
221 
222 LOCAL(void)
emit_dac(j_compress_ptr cinfo)223 emit_dac (j_compress_ptr cinfo)
224 /* Emit a DAC marker */
225 /* Since the useful info is so small, we want to emit all the tables in */
226 /* one DAC marker.  Therefore this routine does its own scan of the table. */
227 {
228 #ifdef C_ARITH_CODING_SUPPORTED
229   char dc_in_use[NUM_ARITH_TBLS];
230   char ac_in_use[NUM_ARITH_TBLS];
231   int length, i;
232   jpeg_component_info *compptr;
233 
234   for (i = 0; i < NUM_ARITH_TBLS; i++)
235     dc_in_use[i] = ac_in_use[i] = 0;
236 
237   for (i = 0; i < cinfo->comps_in_scan; i++) {
238     compptr = cinfo->cur_comp_info[i];
239     dc_in_use[compptr->dc_tbl_no] = 1;
240     ac_in_use[compptr->ac_tbl_no] = 1;
241   }
242 
243   length = 0;
244   for (i = 0; i < NUM_ARITH_TBLS; i++)
245     length += dc_in_use[i] + ac_in_use[i];
246 
247   emit_marker(cinfo, M_DAC);
248 
249   emit_2bytes(cinfo, length*2 + 2);
250 
251   for (i = 0; i < NUM_ARITH_TBLS; i++) {
252     if (dc_in_use[i]) {
253       emit_byte(cinfo, i);
254       emit_byte(cinfo, cinfo->arith_dc_L[i] + (cinfo->arith_dc_U[i]<<4));
255     }
256     if (ac_in_use[i]) {
257       emit_byte(cinfo, i + 0x10);
258       emit_byte(cinfo, cinfo->arith_ac_K[i]);
259     }
260   }
261 #endif /* C_ARITH_CODING_SUPPORTED */
262 }
263 
264 
265 LOCAL(void)
emit_dri(j_compress_ptr cinfo)266 emit_dri (j_compress_ptr cinfo)
267 /* Emit a DRI marker */
268 {
269   emit_marker(cinfo, M_DRI);
270 
271   emit_2bytes(cinfo, 4);	/* fixed length */
272 
273   emit_2bytes(cinfo, (int) cinfo->restart_interval);
274 }
275 
276 
277 LOCAL(void)
emit_sof(j_compress_ptr cinfo,JPEG_MARKER code)278 emit_sof (j_compress_ptr cinfo, JPEG_MARKER code)
279 /* Emit a SOF marker */
280 {
281   int ci;
282   jpeg_component_info *compptr;
283 
284   emit_marker(cinfo, code);
285 
286   emit_2bytes(cinfo, 3 * cinfo->num_components + 2 + 5 + 1); /* length */
287 
288   /* Make sure image isn't bigger than SOF field can handle */
289   if ((long) cinfo->image_height > 65535L ||
290       (long) cinfo->image_width > 65535L)
291     ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) 65535);
292 
293   emit_byte(cinfo, cinfo->data_precision);
294   emit_2bytes(cinfo, (int) cinfo->image_height);
295   emit_2bytes(cinfo, (int) cinfo->image_width);
296 
297   emit_byte(cinfo, cinfo->num_components);
298 
299   for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
300        ci++, compptr++) {
301     emit_byte(cinfo, compptr->component_id);
302     emit_byte(cinfo, (compptr->h_samp_factor << 4) + compptr->v_samp_factor);
303     emit_byte(cinfo, compptr->quant_tbl_no);
304   }
305 }
306 
307 
308 LOCAL(void)
emit_sos(j_compress_ptr cinfo)309 emit_sos (j_compress_ptr cinfo)
310 /* Emit a SOS marker */
311 {
312   int i, td, ta;
313   jpeg_component_info *compptr;
314 
315   emit_marker(cinfo, M_SOS);
316 
317   emit_2bytes(cinfo, 2 * cinfo->comps_in_scan + 2 + 1 + 3); /* length */
318 
319   emit_byte(cinfo, cinfo->comps_in_scan);
320 
321   for (i = 0; i < cinfo->comps_in_scan; i++) {
322     compptr = cinfo->cur_comp_info[i];
323     emit_byte(cinfo, compptr->component_id);
324     td = compptr->dc_tbl_no;
325     ta = compptr->ac_tbl_no;
326     if (cinfo->progressive_mode) {
327       /* Progressive mode: only DC or only AC tables are used in one scan;
328        * furthermore, Huffman coding of DC refinement uses no table at all.
329        * We emit 0 for unused field(s); this is recommended by the P&M text
330        * but does not seem to be specified in the standard.
331        */
332       if (cinfo->Ss == 0) {
333 	ta = 0;			/* DC scan */
334 	if (cinfo->Ah != 0 && !cinfo->arith_code)
335 	  td = 0;		/* no DC table either */
336       } else {
337 	td = 0;			/* AC scan */
338       }
339     }
340     emit_byte(cinfo, (td << 4) + ta);
341   }
342 
343   emit_byte(cinfo, cinfo->Ss);
344   emit_byte(cinfo, cinfo->Se);
345   emit_byte(cinfo, (cinfo->Ah << 4) + cinfo->Al);
346 }
347 
348 
349 LOCAL(void)
emit_jfif_app0(j_compress_ptr cinfo)350 emit_jfif_app0 (j_compress_ptr cinfo)
351 /* Emit a JFIF-compliant APP0 marker */
352 {
353   /*
354    * Length of APP0 block	(2 bytes)
355    * Block ID			(4 bytes - ASCII "JFIF")
356    * Zero byte			(1 byte to terminate the ID string)
357    * Version Major, Minor	(2 bytes - major first)
358    * Units			(1 byte - 0x00 = none, 0x01 = inch, 0x02 = cm)
359    * Xdpu			(2 bytes - dots per unit horizontal)
360    * Ydpu			(2 bytes - dots per unit vertical)
361    * Thumbnail X size		(1 byte)
362    * Thumbnail Y size		(1 byte)
363    */
364 
365   emit_marker(cinfo, M_APP0);
366 
367   emit_2bytes(cinfo, 2 + 4 + 1 + 2 + 1 + 2 + 2 + 1 + 1); /* length */
368 
369   emit_byte(cinfo, 0x4A);	/* Identifier: ASCII "JFIF" */
370   emit_byte(cinfo, 0x46);
371   emit_byte(cinfo, 0x49);
372   emit_byte(cinfo, 0x46);
373   emit_byte(cinfo, 0);
374   emit_byte(cinfo, cinfo->JFIF_major_version); /* Version fields */
375   emit_byte(cinfo, cinfo->JFIF_minor_version);
376   emit_byte(cinfo, cinfo->density_unit); /* Pixel size information */
377   emit_2bytes(cinfo, (int) cinfo->X_density);
378   emit_2bytes(cinfo, (int) cinfo->Y_density);
379   emit_byte(cinfo, 0);		/* No thumbnail image */
380   emit_byte(cinfo, 0);
381 }
382 
383 
384 LOCAL(void)
emit_adobe_app14(j_compress_ptr cinfo)385 emit_adobe_app14 (j_compress_ptr cinfo)
386 /* Emit an Adobe APP14 marker */
387 {
388   /*
389    * Length of APP14 block	(2 bytes)
390    * Block ID			(5 bytes - ASCII "Adobe")
391    * Version Number		(2 bytes - currently 100)
392    * Flags0			(2 bytes - currently 0)
393    * Flags1			(2 bytes - currently 0)
394    * Color transform		(1 byte)
395    *
396    * Although Adobe TN 5116 mentions Version = 101, all the Adobe files
397    * now in circulation seem to use Version = 100, so that's what we write.
398    *
399    * We write the color transform byte as 1 if the JPEG color space is
400    * YCbCr, 2 if it's YCCK, 0 otherwise.  Adobe's definition has to do with
401    * whether the encoder performed a transformation, which is pretty useless.
402    */
403 
404   emit_marker(cinfo, M_APP14);
405 
406   emit_2bytes(cinfo, 2 + 5 + 2 + 2 + 2 + 1); /* length */
407 
408   emit_byte(cinfo, 0x41);	/* Identifier: ASCII "Adobe" */
409   emit_byte(cinfo, 0x64);
410   emit_byte(cinfo, 0x6F);
411   emit_byte(cinfo, 0x62);
412   emit_byte(cinfo, 0x65);
413   emit_2bytes(cinfo, 100);	/* Version */
414   emit_2bytes(cinfo, 0);	/* Flags0 */
415   emit_2bytes(cinfo, 0);	/* Flags1 */
416   switch (cinfo->jpeg_color_space) {
417   case JCS_YCbCr:
418     emit_byte(cinfo, 1);	/* Color transform = 1 */
419     break;
420   case JCS_YCCK:
421     emit_byte(cinfo, 2);	/* Color transform = 2 */
422     break;
423   default:
424     emit_byte(cinfo, 0);	/* Color transform = 0 */
425     break;
426   }
427 }
428 
429 
430 /*
431  * These routines allow writing an arbitrary marker with parameters.
432  * The only intended use is to emit COM or APPn markers after calling
433  * write_file_header and before calling write_frame_header.
434  * Other uses are not guaranteed to produce desirable results.
435  * Counting the parameter bytes properly is the caller's responsibility.
436  */
437 
438 METHODDEF(void)
write_marker_header(j_compress_ptr cinfo,int marker,unsigned int datalen)439 write_marker_header (j_compress_ptr cinfo, int marker, unsigned int datalen)
440 /* Emit an arbitrary marker header */
441 {
442   if (datalen > (unsigned int) 65533)		/* safety check */
443     ERREXIT(cinfo, JERR_BAD_LENGTH);
444 
445   emit_marker(cinfo, (JPEG_MARKER) marker);
446 
447   emit_2bytes(cinfo, (int) (datalen + 2));	/* total length */
448 }
449 
450 METHODDEF(void)
write_marker_byte(j_compress_ptr cinfo,int val)451 write_marker_byte (j_compress_ptr cinfo, int val)
452 /* Emit one byte of marker parameters following write_marker_header */
453 {
454   emit_byte(cinfo, val);
455 }
456 
457 
458 /*
459  * Write datastream header.
460  * This consists of an SOI and optional APPn markers.
461  * We recommend use of the JFIF marker, but not the Adobe marker,
462  * when using YCbCr or grayscale data.  The JFIF marker should NOT
463  * be used for any other JPEG colorspace.  The Adobe marker is helpful
464  * to distinguish RGB, CMYK, and YCCK colorspaces.
465  * Note that an application can write additional header markers after
466  * jpeg_start_compress returns.
467  */
468 
469 METHODDEF(void)
write_file_header(j_compress_ptr cinfo)470 write_file_header (j_compress_ptr cinfo)
471 {
472   my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
473 
474   emit_marker(cinfo, M_SOI);	/* first the SOI */
475 
476   /* SOI is defined to reset restart interval to 0 */
477   marker->last_restart_interval = 0;
478 
479   if (cinfo->write_JFIF_header)	/* next an optional JFIF APP0 */
480     emit_jfif_app0(cinfo);
481   if (cinfo->write_Adobe_marker) /* next an optional Adobe APP14 */
482     emit_adobe_app14(cinfo);
483 }
484 
485 
486 /*
487  * Write frame header.
488  * This consists of DQT and SOFn markers.
489  * Note that we do not emit the SOF until we have emitted the DQT(s).
490  * This avoids compatibility problems with incorrect implementations that
491  * try to error-check the quant table numbers as soon as they see the SOF.
492  */
493 
494 METHODDEF(void)
write_frame_header(j_compress_ptr cinfo)495 write_frame_header (j_compress_ptr cinfo)
496 {
497   int ci, prec;
498   boolean is_baseline;
499   jpeg_component_info *compptr;
500 
501   /* Emit DQT for each quantization table.
502    * Note that emit_dqt() suppresses any duplicate tables.
503    */
504   prec = 0;
505   for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
506        ci++, compptr++) {
507     prec += emit_dqt(cinfo, compptr->quant_tbl_no);
508   }
509   /* now prec is nonzero iff there are any 16-bit quant tables. */
510 
511   /* Check for a non-baseline specification.
512    * Note we assume that Huffman table numbers won't be changed later.
513    */
514   if (cinfo->arith_code || cinfo->progressive_mode ||
515       cinfo->data_precision != 8) {
516     is_baseline = FALSE;
517   } else {
518     is_baseline = TRUE;
519     for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
520 	 ci++, compptr++) {
521       if (compptr->dc_tbl_no > 1 || compptr->ac_tbl_no > 1)
522 	is_baseline = FALSE;
523     }
524     if (prec && is_baseline) {
525       is_baseline = FALSE;
526       /* If it's baseline except for quantizer size, warn the user */
527       TRACEMS(cinfo, 0, JTRC_16BIT_TABLES);
528     }
529   }
530 
531   /* Emit the proper SOF marker */
532   if (cinfo->arith_code) {
533     emit_sof(cinfo, M_SOF9);	/* SOF code for arithmetic coding */
534   } else {
535     if (cinfo->progressive_mode)
536       emit_sof(cinfo, M_SOF2);	/* SOF code for progressive Huffman */
537     else if (is_baseline)
538       emit_sof(cinfo, M_SOF0);	/* SOF code for baseline implementation */
539     else
540       emit_sof(cinfo, M_SOF1);	/* SOF code for non-baseline Huffman file */
541   }
542 }
543 
544 
545 /*
546  * Write scan header.
547  * This consists of DHT or DAC markers, optional DRI, and SOS.
548  * Compressed data will be written following the SOS.
549  */
550 
551 METHODDEF(void)
write_scan_header(j_compress_ptr cinfo)552 write_scan_header (j_compress_ptr cinfo)
553 {
554   my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
555   int i;
556   jpeg_component_info *compptr;
557 
558   if (cinfo->arith_code) {
559     /* Emit arith conditioning info.  We may have some duplication
560      * if the file has multiple scans, but it's so small it's hardly
561      * worth worrying about.
562      */
563     emit_dac(cinfo);
564   } else {
565     /* Emit Huffman tables.
566      * Note that emit_dht() suppresses any duplicate tables.
567      */
568     for (i = 0; i < cinfo->comps_in_scan; i++) {
569       compptr = cinfo->cur_comp_info[i];
570       if (cinfo->progressive_mode) {
571 	/* Progressive mode: only DC or only AC tables are used in one scan */
572 	if (cinfo->Ss == 0) {
573 	  if (cinfo->Ah == 0)	/* DC needs no table for refinement scan */
574 	    emit_dht(cinfo, compptr->dc_tbl_no, FALSE);
575 	} else {
576 	  emit_dht(cinfo, compptr->ac_tbl_no, TRUE);
577 	}
578       } else {
579 	/* Sequential mode: need both DC and AC tables */
580 	emit_dht(cinfo, compptr->dc_tbl_no, FALSE);
581 	emit_dht(cinfo, compptr->ac_tbl_no, TRUE);
582       }
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 
602 METHODDEF(void)
write_file_trailer(j_compress_ptr cinfo)603 write_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 
616 METHODDEF(void)
write_tables_only(j_compress_ptr cinfo)617 write_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 
645 GLOBAL(void)
jinit_marker_writer(j_compress_ptr cinfo)646 jinit_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 
667 #endif //_FX_JPEG_TURBO_
668