1/*
2 * jcapimin.c
3 *
4 * This file was part of the Independent JPEG Group's software:
5 * Copyright (C) 1994-1998, Thomas G. Lane.
6 * Modified 2003-2010 by Guido Vollbeding.
7 * It was modified by The libjpeg-turbo Project to include only code relevant
8 * to libjpeg-turbo.
9 * For conditions of distribution and use, see the accompanying README.ijg
10 * file.
11 *
12 * This file contains application interface code for the compression half
13 * of the JPEG library.  These are the "minimum" API routines that may be
14 * needed in either the normal full-compression case or the transcoding-only
15 * case.
16 *
17 * Most of the routines intended to be called directly by an application
18 * are in this file or in jcapistd.c.  But also see jcparam.c for
19 * parameter-setup helper routines, jcomapi.c for routines shared by
20 * compression and decompression, and jctrans.c for the transcoding case.
21 */
22
23#define JPEG_INTERNALS
24#include "jinclude.h"
25#include "jpeglib.h"
26
27
28/*
29 * Initialization of a JPEG compression object.
30 * The error manager must already be set up (in case memory manager fails).
31 */
32
33GLOBAL(void)
34jpeg_CreateCompress (j_compress_ptr cinfo, int version, size_t structsize)
35{
36  int i;
37
38  /* Guard against version mismatches between library and caller. */
39  cinfo->mem = NULL;            /* so jpeg_destroy knows mem mgr not called */
40  if (version != JPEG_LIB_VERSION)
41    ERREXIT2(cinfo, JERR_BAD_LIB_VERSION, JPEG_LIB_VERSION, version);
42  if (structsize != sizeof(struct jpeg_compress_struct))
43    ERREXIT2(cinfo, JERR_BAD_STRUCT_SIZE,
44             (int) sizeof(struct jpeg_compress_struct), (int) structsize);
45
46  /* For debugging purposes, we zero the whole master structure.
47   * But the application has already set the err pointer, and may have set
48   * client_data, so we have to save and restore those fields.
49   * Note: if application hasn't set client_data, tools like Purify may
50   * complain here.
51   */
52  {
53    struct jpeg_error_mgr *err = cinfo->err;
54    void *client_data = cinfo->client_data; /* ignore Purify complaint here */
55    MEMZERO(cinfo, sizeof(struct jpeg_compress_struct));
56    cinfo->err = err;
57    cinfo->client_data = client_data;
58  }
59  cinfo->is_decompressor = FALSE;
60
61  /* Initialize a memory manager instance for this object */
62  jinit_memory_mgr((j_common_ptr) cinfo);
63
64  /* Zero out pointers to permanent structures. */
65  cinfo->progress = NULL;
66  cinfo->dest = NULL;
67
68  cinfo->comp_info = NULL;
69
70  for (i = 0; i < NUM_QUANT_TBLS; i++) {
71    cinfo->quant_tbl_ptrs[i] = NULL;
72#if JPEG_LIB_VERSION >= 70
73    cinfo->q_scale_factor[i] = 100;
74#endif
75  }
76
77  for (i = 0; i < NUM_HUFF_TBLS; i++) {
78    cinfo->dc_huff_tbl_ptrs[i] = NULL;
79    cinfo->ac_huff_tbl_ptrs[i] = NULL;
80  }
81
82#if JPEG_LIB_VERSION >= 80
83  /* Must do it here for emit_dqt in case jpeg_write_tables is used */
84  cinfo->block_size = DCTSIZE;
85  cinfo->natural_order = jpeg_natural_order;
86  cinfo->lim_Se = DCTSIZE2-1;
87#endif
88
89  cinfo->script_space = NULL;
90
91  cinfo->input_gamma = 1.0;     /* in case application forgets */
92
93  /* OK, I'm ready */
94  cinfo->global_state = CSTATE_START;
95}
96
97
98/*
99 * Destruction of a JPEG compression object
100 */
101
102GLOBAL(void)
103jpeg_destroy_compress (j_compress_ptr cinfo)
104{
105  jpeg_destroy((j_common_ptr) cinfo); /* use common routine */
106}
107
108
109/*
110 * Abort processing of a JPEG compression operation,
111 * but don't destroy the object itself.
112 */
113
114GLOBAL(void)
115jpeg_abort_compress (j_compress_ptr cinfo)
116{
117  jpeg_abort((j_common_ptr) cinfo); /* use common routine */
118}
119
120
121/*
122 * Forcibly suppress or un-suppress all quantization and Huffman tables.
123 * Marks all currently defined tables as already written (if suppress)
124 * or not written (if !suppress).  This will control whether they get emitted
125 * by a subsequent jpeg_start_compress call.
126 *
127 * This routine is exported for use by applications that want to produce
128 * abbreviated JPEG datastreams.  It logically belongs in jcparam.c, but
129 * since it is called by jpeg_start_compress, we put it here --- otherwise
130 * jcparam.o would be linked whether the application used it or not.
131 */
132
133GLOBAL(void)
134jpeg_suppress_tables (j_compress_ptr cinfo, boolean suppress)
135{
136  int i;
137  JQUANT_TBL *qtbl;
138  JHUFF_TBL *htbl;
139
140  for (i = 0; i < NUM_QUANT_TBLS; i++) {
141    if ((qtbl = cinfo->quant_tbl_ptrs[i]) != NULL)
142      qtbl->sent_table = suppress;
143  }
144
145  for (i = 0; i < NUM_HUFF_TBLS; i++) {
146    if ((htbl = cinfo->dc_huff_tbl_ptrs[i]) != NULL)
147      htbl->sent_table = suppress;
148    if ((htbl = cinfo->ac_huff_tbl_ptrs[i]) != NULL)
149      htbl->sent_table = suppress;
150  }
151}
152
153
154/*
155 * Finish JPEG compression.
156 *
157 * If a multipass operating mode was selected, this may do a great deal of
158 * work including most of the actual output.
159 */
160
161GLOBAL(void)
162jpeg_finish_compress (j_compress_ptr cinfo)
163{
164  JDIMENSION iMCU_row;
165
166  if (cinfo->global_state == CSTATE_SCANNING ||
167      cinfo->global_state == CSTATE_RAW_OK) {
168    /* Terminate first pass */
169    if (cinfo->next_scanline < cinfo->image_height)
170      ERREXIT(cinfo, JERR_TOO_LITTLE_DATA);
171    (*cinfo->master->finish_pass) (cinfo);
172  } else if (cinfo->global_state != CSTATE_WRCOEFS)
173    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
174  /* Perform any remaining passes */
175  while (! cinfo->master->is_last_pass) {
176    (*cinfo->master->prepare_for_pass) (cinfo);
177    for (iMCU_row = 0; iMCU_row < cinfo->total_iMCU_rows; iMCU_row++) {
178      if (cinfo->progress != NULL) {
179        cinfo->progress->pass_counter = (long) iMCU_row;
180        cinfo->progress->pass_limit = (long) cinfo->total_iMCU_rows;
181        (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
182      }
183      /* We bypass the main controller and invoke coef controller directly;
184       * all work is being done from the coefficient buffer.
185       */
186      if (! (*cinfo->coef->compress_data) (cinfo, (JSAMPIMAGE) NULL))
187        ERREXIT(cinfo, JERR_CANT_SUSPEND);
188    }
189    (*cinfo->master->finish_pass) (cinfo);
190  }
191  /* Write EOI, do final cleanup */
192  (*cinfo->marker->write_file_trailer) (cinfo);
193  (*cinfo->dest->term_destination) (cinfo);
194  /* We can use jpeg_abort to release memory and reset global_state */
195  jpeg_abort((j_common_ptr) cinfo);
196}
197
198
199/*
200 * Write a special marker.
201 * This is only recommended for writing COM or APPn markers.
202 * Must be called after jpeg_start_compress() and before
203 * first call to jpeg_write_scanlines() or jpeg_write_raw_data().
204 */
205
206GLOBAL(void)
207jpeg_write_marker (j_compress_ptr cinfo, int marker,
208                   const JOCTET *dataptr, unsigned int datalen)
209{
210  void (*write_marker_byte) (j_compress_ptr info, int val);
211
212  if (cinfo->next_scanline != 0 ||
213      (cinfo->global_state != CSTATE_SCANNING &&
214       cinfo->global_state != CSTATE_RAW_OK &&
215       cinfo->global_state != CSTATE_WRCOEFS))
216    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
217
218  (*cinfo->marker->write_marker_header) (cinfo, marker, datalen);
219  write_marker_byte = cinfo->marker->write_marker_byte; /* copy for speed */
220  while (datalen--) {
221    (*write_marker_byte) (cinfo, *dataptr);
222    dataptr++;
223  }
224}
225
226/* Same, but piecemeal. */
227
228GLOBAL(void)
229jpeg_write_m_header (j_compress_ptr cinfo, int marker, unsigned int datalen)
230{
231  if (cinfo->next_scanline != 0 ||
232      (cinfo->global_state != CSTATE_SCANNING &&
233       cinfo->global_state != CSTATE_RAW_OK &&
234       cinfo->global_state != CSTATE_WRCOEFS))
235    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
236
237  (*cinfo->marker->write_marker_header) (cinfo, marker, datalen);
238}
239
240GLOBAL(void)
241jpeg_write_m_byte (j_compress_ptr cinfo, int val)
242{
243  (*cinfo->marker->write_marker_byte) (cinfo, val);
244}
245
246
247/*
248 * Alternate compression function: just write an abbreviated table file.
249 * Before calling this, all parameters and a data destination must be set up.
250 *
251 * To produce a pair of files containing abbreviated tables and abbreviated
252 * image data, one would proceed as follows:
253 *
254 *              initialize JPEG object
255 *              set JPEG parameters
256 *              set destination to table file
257 *              jpeg_write_tables(cinfo);
258 *              set destination to image file
259 *              jpeg_start_compress(cinfo, FALSE);
260 *              write data...
261 *              jpeg_finish_compress(cinfo);
262 *
263 * jpeg_write_tables has the side effect of marking all tables written
264 * (same as jpeg_suppress_tables(..., TRUE)).  Thus a subsequent start_compress
265 * will not re-emit the tables unless it is passed write_all_tables=TRUE.
266 */
267
268GLOBAL(void)
269jpeg_write_tables (j_compress_ptr cinfo)
270{
271  if (cinfo->global_state != CSTATE_START)
272    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
273
274  /* (Re)initialize error mgr and destination modules */
275  (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
276  (*cinfo->dest->init_destination) (cinfo);
277  /* Initialize the marker writer ... bit of a crock to do it here. */
278  jinit_marker_writer(cinfo);
279  /* Write them tables! */
280  (*cinfo->marker->write_tables_only) (cinfo);
281  /* And clean up. */
282  (*cinfo->dest->term_destination) (cinfo);
283  /*
284   * In library releases up through v6a, we called jpeg_abort() here to free
285   * any working memory allocated by the destination manager and marker
286   * writer.  Some applications had a problem with that: they allocated space
287   * of their own from the library memory manager, and didn't want it to go
288   * away during write_tables.  So now we do nothing.  This will cause a
289   * memory leak if an app calls write_tables repeatedly without doing a full
290   * compression cycle or otherwise resetting the JPEG object.  However, that
291   * seems less bad than unexpectedly freeing memory in the normal case.
292   * An app that prefers the old behavior can call jpeg_abort for itself after
293   * each call to jpeg_write_tables().
294   */
295}
296