1/*
2 * jcapimin.c
3 *
4 * Copyright (C) 1994-1998, Thomas G. Lane.
5 * Modified 2003-2010 by Guido Vollbeding.
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 application interface code for the compression half
10 * of the JPEG library.  These are the "minimum" API routines that may be
11 * needed in either the normal full-compression case or the transcoding-only
12 * case.
13 *
14 * Most of the routines intended to be called directly by an application
15 * are in this file or in jcapistd.c.  But also see jcparam.c for
16 * parameter-setup helper routines, jcomapi.c for routines shared by
17 * compression and decompression, and jctrans.c for the transcoding case.
18 */
19
20#define JPEG_INTERNALS
21#include "jinclude.h"
22#include "jpeglib.h"
23
24
25/*
26 * Initialization of a JPEG compression object.
27 * The error manager must already be set up (in case memory manager fails).
28 */
29
30GLOBAL(void)
31jpeg_CreateCompress (j_compress_ptr cinfo, int version, size_t structsize)
32{
33  int i;
34
35  /* Guard against version mismatches between library and caller. */
36  cinfo->mem = NULL;		/* so jpeg_destroy knows mem mgr not called */
37  if (version != JPEG_LIB_VERSION)
38    ERREXIT2(cinfo, JERR_BAD_LIB_VERSION, JPEG_LIB_VERSION, version);
39  if (structsize != SIZEOF(struct jpeg_compress_struct))
40    ERREXIT2(cinfo, JERR_BAD_STRUCT_SIZE,
41	     (int) SIZEOF(struct jpeg_compress_struct), (int) structsize);
42
43  /* For debugging purposes, we zero the whole master structure.
44   * But the application has already set the err pointer, and may have set
45   * client_data, so we have to save and restore those fields.
46   * Note: if application hasn't set client_data, tools like Purify may
47   * complain here.
48   */
49  {
50    struct jpeg_error_mgr * err = cinfo->err;
51    void * client_data = cinfo->client_data; /* ignore Purify complaint here */
52    MEMZERO(cinfo, SIZEOF(struct jpeg_compress_struct));
53    cinfo->err = err;
54    cinfo->client_data = client_data;
55  }
56  cinfo->is_decompressor = FALSE;
57
58  /* Initialize a memory manager instance for this object */
59  jinit_memory_mgr((j_common_ptr) cinfo);
60
61  /* Zero out pointers to permanent structures. */
62  cinfo->progress = NULL;
63  cinfo->dest = NULL;
64
65  cinfo->comp_info = NULL;
66
67  for (i = 0; i < NUM_QUANT_TBLS; i++) {
68    cinfo->quant_tbl_ptrs[i] = NULL;
69#if JPEG_LIB_VERSION >= 70
70    cinfo->q_scale_factor[i] = 100;
71#endif
72  }
73
74  for (i = 0; i < NUM_HUFF_TBLS; i++) {
75    cinfo->dc_huff_tbl_ptrs[i] = NULL;
76    cinfo->ac_huff_tbl_ptrs[i] = NULL;
77  }
78
79#if JPEG_LIB_VERSION >= 80
80  /* Must do it here for emit_dqt in case jpeg_write_tables is used */
81  cinfo->block_size = DCTSIZE;
82  cinfo->natural_order = jpeg_natural_order;
83  cinfo->lim_Se = DCTSIZE2-1;
84#endif
85
86  cinfo->script_space = NULL;
87
88  cinfo->input_gamma = 1.0;	/* in case application forgets */
89
90  /* OK, I'm ready */
91  cinfo->global_state = CSTATE_START;
92}
93
94
95/*
96 * Destruction of a JPEG compression object
97 */
98
99GLOBAL(void)
100jpeg_destroy_compress (j_compress_ptr cinfo)
101{
102  jpeg_destroy((j_common_ptr) cinfo); /* use common routine */
103}
104
105
106/*
107 * Abort processing of a JPEG compression operation,
108 * but don't destroy the object itself.
109 */
110
111GLOBAL(void)
112jpeg_abort_compress (j_compress_ptr cinfo)
113{
114  jpeg_abort((j_common_ptr) cinfo); /* use common routine */
115}
116
117
118/*
119 * Forcibly suppress or un-suppress all quantization and Huffman tables.
120 * Marks all currently defined tables as already written (if suppress)
121 * or not written (if !suppress).  This will control whether they get emitted
122 * by a subsequent jpeg_start_compress call.
123 *
124 * This routine is exported for use by applications that want to produce
125 * abbreviated JPEG datastreams.  It logically belongs in jcparam.c, but
126 * since it is called by jpeg_start_compress, we put it here --- otherwise
127 * jcparam.o would be linked whether the application used it or not.
128 */
129
130GLOBAL(void)
131jpeg_suppress_tables (j_compress_ptr cinfo, boolean suppress)
132{
133  int i;
134  JQUANT_TBL * qtbl;
135  JHUFF_TBL * htbl;
136
137  for (i = 0; i < NUM_QUANT_TBLS; i++) {
138    if ((qtbl = cinfo->quant_tbl_ptrs[i]) != NULL)
139      qtbl->sent_table = suppress;
140  }
141
142  for (i = 0; i < NUM_HUFF_TBLS; i++) {
143    if ((htbl = cinfo->dc_huff_tbl_ptrs[i]) != NULL)
144      htbl->sent_table = suppress;
145    if ((htbl = cinfo->ac_huff_tbl_ptrs[i]) != NULL)
146      htbl->sent_table = suppress;
147  }
148}
149
150
151/*
152 * Finish JPEG compression.
153 *
154 * If a multipass operating mode was selected, this may do a great deal of
155 * work including most of the actual output.
156 */
157
158GLOBAL(void)
159jpeg_finish_compress (j_compress_ptr cinfo)
160{
161  JDIMENSION iMCU_row;
162
163  if (cinfo->global_state == CSTATE_SCANNING ||
164      cinfo->global_state == CSTATE_RAW_OK) {
165    /* Terminate first pass */
166    if (cinfo->next_scanline < cinfo->image_height)
167      ERREXIT(cinfo, JERR_TOO_LITTLE_DATA);
168    (*cinfo->master->finish_pass) (cinfo);
169  } else if (cinfo->global_state != CSTATE_WRCOEFS)
170    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
171  /* Perform any remaining passes */
172  while (! cinfo->master->is_last_pass) {
173    (*cinfo->master->prepare_for_pass) (cinfo);
174    for (iMCU_row = 0; iMCU_row < cinfo->total_iMCU_rows; iMCU_row++) {
175      if (cinfo->progress != NULL) {
176	cinfo->progress->pass_counter = (long) iMCU_row;
177	cinfo->progress->pass_limit = (long) cinfo->total_iMCU_rows;
178	(*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
179      }
180      /* We bypass the main controller and invoke coef controller directly;
181       * all work is being done from the coefficient buffer.
182       */
183      if (! (*cinfo->coef->compress_data) (cinfo, (JSAMPIMAGE) NULL))
184	ERREXIT(cinfo, JERR_CANT_SUSPEND);
185    }
186    (*cinfo->master->finish_pass) (cinfo);
187  }
188  /* Write EOI, do final cleanup */
189  (*cinfo->marker->write_file_trailer) (cinfo);
190  (*cinfo->dest->term_destination) (cinfo);
191  /* We can use jpeg_abort to release memory and reset global_state */
192  jpeg_abort((j_common_ptr) cinfo);
193}
194
195
196/*
197 * Write a special marker.
198 * This is only recommended for writing COM or APPn markers.
199 * Must be called after jpeg_start_compress() and before
200 * first call to jpeg_write_scanlines() or jpeg_write_raw_data().
201 */
202
203GLOBAL(void)
204jpeg_write_marker (j_compress_ptr cinfo, int marker,
205		   const JOCTET *dataptr, unsigned int datalen)
206{
207  JMETHOD(void, write_marker_byte, (j_compress_ptr info, int val));
208
209  if (cinfo->next_scanline != 0 ||
210      (cinfo->global_state != CSTATE_SCANNING &&
211       cinfo->global_state != CSTATE_RAW_OK &&
212       cinfo->global_state != CSTATE_WRCOEFS))
213    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
214
215  (*cinfo->marker->write_marker_header) (cinfo, marker, datalen);
216  write_marker_byte = cinfo->marker->write_marker_byte;	/* copy for speed */
217  while (datalen--) {
218    (*write_marker_byte) (cinfo, *dataptr);
219    dataptr++;
220  }
221}
222
223/* Same, but piecemeal. */
224
225GLOBAL(void)
226jpeg_write_m_header (j_compress_ptr cinfo, int marker, unsigned int datalen)
227{
228  if (cinfo->next_scanline != 0 ||
229      (cinfo->global_state != CSTATE_SCANNING &&
230       cinfo->global_state != CSTATE_RAW_OK &&
231       cinfo->global_state != CSTATE_WRCOEFS))
232    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
233
234  (*cinfo->marker->write_marker_header) (cinfo, marker, datalen);
235}
236
237GLOBAL(void)
238jpeg_write_m_byte (j_compress_ptr cinfo, int val)
239{
240  (*cinfo->marker->write_marker_byte) (cinfo, val);
241}
242
243
244/*
245 * Alternate compression function: just write an abbreviated table file.
246 * Before calling this, all parameters and a data destination must be set up.
247 *
248 * To produce a pair of files containing abbreviated tables and abbreviated
249 * image data, one would proceed as follows:
250 *
251 *		initialize JPEG object
252 *		set JPEG parameters
253 *		set destination to table file
254 *		jpeg_write_tables(cinfo);
255 *		set destination to image file
256 *		jpeg_start_compress(cinfo, FALSE);
257 *		write data...
258 *		jpeg_finish_compress(cinfo);
259 *
260 * jpeg_write_tables has the side effect of marking all tables written
261 * (same as jpeg_suppress_tables(..., TRUE)).  Thus a subsequent start_compress
262 * will not re-emit the tables unless it is passed write_all_tables=TRUE.
263 */
264
265GLOBAL(void)
266jpeg_write_tables (j_compress_ptr cinfo)
267{
268  if (cinfo->global_state != CSTATE_START)
269    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
270
271  /* (Re)initialize error mgr and destination modules */
272  (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
273  (*cinfo->dest->init_destination) (cinfo);
274  /* Initialize the marker writer ... bit of a crock to do it here. */
275  jinit_marker_writer(cinfo);
276  /* Write them tables! */
277  (*cinfo->marker->write_tables_only) (cinfo);
278  /* And clean up. */
279  (*cinfo->dest->term_destination) (cinfo);
280  /*
281   * In library releases up through v6a, we called jpeg_abort() here to free
282   * any working memory allocated by the destination manager and marker
283   * writer.  Some applications had a problem with that: they allocated space
284   * of their own from the library memory manager, and didn't want it to go
285   * away during write_tables.  So now we do nothing.  This will cause a
286   * memory leak if an app calls write_tables repeatedly without doing a full
287   * compression cycle or otherwise resetting the JPEG object.  However, that
288   * seems less bad than unexpectedly freeing memory in the normal case.
289   * An app that prefers the old behavior can call jpeg_abort for itself after
290   * each call to jpeg_write_tables().
291   */
292}
293