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/libjpeg/jcapimin.c

https://code.google.com/p/xee/
C | 280 lines | 133 code | 42 blank | 105 comment | 39 complexity | c2b39cff18077c2601c7f013bc461764 MD5 | raw file
  1/*
  2 * jcapimin.c
  3 *
  4 * Copyright (C) 1994-1998, Thomas G. Lane.
  5 * This file is part of the Independent JPEG Group's software.
  6 * For conditions of distribution and use, see the accompanying README file.
  7 *
  8 * This file contains application interface code for the compression half
  9 * of the JPEG library.  These are the "minimum" API routines that may be
 10 * needed in either the normal full-compression case or the transcoding-only
 11 * case.
 12 *
 13 * Most of the routines intended to be called directly by an application
 14 * are in this file or in jcapistd.c.  But also see jcparam.c for
 15 * parameter-setup helper routines, jcomapi.c for routines shared by
 16 * compression and decompression, and jctrans.c for the transcoding case.
 17 */
 18
 19#define JPEG_INTERNALS
 20#include "jinclude.h"
 21#include "jpeglib.h"
 22
 23
 24/*
 25 * Initialization of a JPEG compression object.
 26 * The error manager must already be set up (in case memory manager fails).
 27 */
 28
 29GLOBAL(void)
 30jpeg_CreateCompress (j_compress_ptr cinfo, int version, size_t structsize)
 31{
 32  int i;
 33
 34  /* Guard against version mismatches between library and caller. */
 35  cinfo->mem = NULL;		/* so jpeg_destroy knows mem mgr not called */
 36  if (version != JPEG_LIB_VERSION)
 37    ERREXIT2(cinfo, JERR_BAD_LIB_VERSION, JPEG_LIB_VERSION, version);
 38  if (structsize != SIZEOF(struct jpeg_compress_struct))
 39    ERREXIT2(cinfo, JERR_BAD_STRUCT_SIZE, 
 40	     (int) SIZEOF(struct jpeg_compress_struct), (int) structsize);
 41
 42  /* For debugging purposes, we zero the whole master structure.
 43   * But the application has already set the err pointer, and may have set
 44   * client_data, so we have to save and restore those fields.
 45   * Note: if application hasn't set client_data, tools like Purify may
 46   * complain here.
 47   */
 48  {
 49    struct jpeg_error_mgr * err = cinfo->err;
 50    void * client_data = cinfo->client_data; /* ignore Purify complaint here */
 51    MEMZERO(cinfo, SIZEOF(struct jpeg_compress_struct));
 52    cinfo->err = err;
 53    cinfo->client_data = client_data;
 54  }
 55  cinfo->is_decompressor = FALSE;
 56
 57  /* Initialize a memory manager instance for this object */
 58  jinit_memory_mgr((j_common_ptr) cinfo);
 59
 60  /* Zero out pointers to permanent structures. */
 61  cinfo->progress = NULL;
 62  cinfo->dest = NULL;
 63
 64  cinfo->comp_info = NULL;
 65
 66  for (i = 0; i < NUM_QUANT_TBLS; i++)
 67    cinfo->quant_tbl_ptrs[i] = NULL;
 68
 69  for (i = 0; i < NUM_HUFF_TBLS; i++) {
 70    cinfo->dc_huff_tbl_ptrs[i] = NULL;
 71    cinfo->ac_huff_tbl_ptrs[i] = NULL;
 72  }
 73
 74  cinfo->script_space = NULL;
 75
 76  cinfo->input_gamma = 1.0;	/* in case application forgets */
 77
 78  /* OK, I'm ready */
 79  cinfo->global_state = CSTATE_START;
 80}
 81
 82
 83/*
 84 * Destruction of a JPEG compression object
 85 */
 86
 87GLOBAL(void)
 88jpeg_destroy_compress (j_compress_ptr cinfo)
 89{
 90  jpeg_destroy((j_common_ptr) cinfo); /* use common routine */
 91}
 92
 93
 94/*
 95 * Abort processing of a JPEG compression operation,
 96 * but don't destroy the object itself.
 97 */
 98
 99GLOBAL(void)
100jpeg_abort_compress (j_compress_ptr cinfo)
101{
102  jpeg_abort((j_common_ptr) cinfo); /* use common routine */
103}
104
105
106/*
107 * Forcibly suppress or un-suppress all quantization and Huffman tables.
108 * Marks all currently defined tables as already written (if suppress)
109 * or not written (if !suppress).  This will control whether they get emitted
110 * by a subsequent jpeg_start_compress call.
111 *
112 * This routine is exported for use by applications that want to produce
113 * abbreviated JPEG datastreams.  It logically belongs in jcparam.c, but
114 * since it is called by jpeg_start_compress, we put it here --- otherwise
115 * jcparam.o would be linked whether the application used it or not.
116 */
117
118GLOBAL(void)
119jpeg_suppress_tables (j_compress_ptr cinfo, boolean suppress)
120{
121  int i;
122  JQUANT_TBL * qtbl;
123  JHUFF_TBL * htbl;
124
125  for (i = 0; i < NUM_QUANT_TBLS; i++) {
126    if ((qtbl = cinfo->quant_tbl_ptrs[i]) != NULL)
127      qtbl->sent_table = suppress;
128  }
129
130  for (i = 0; i < NUM_HUFF_TBLS; i++) {
131    if ((htbl = cinfo->dc_huff_tbl_ptrs[i]) != NULL)
132      htbl->sent_table = suppress;
133    if ((htbl = cinfo->ac_huff_tbl_ptrs[i]) != NULL)
134      htbl->sent_table = suppress;
135  }
136}
137
138
139/*
140 * Finish JPEG compression.
141 *
142 * If a multipass operating mode was selected, this may do a great deal of
143 * work including most of the actual output.
144 */
145
146GLOBAL(void)
147jpeg_finish_compress (j_compress_ptr cinfo)
148{
149  JDIMENSION iMCU_row;
150
151  if (cinfo->global_state == CSTATE_SCANNING ||
152      cinfo->global_state == CSTATE_RAW_OK) {
153    /* Terminate first pass */
154    if (cinfo->next_scanline < cinfo->image_height)
155      ERREXIT(cinfo, JERR_TOO_LITTLE_DATA);
156    (*cinfo->master->finish_pass) (cinfo);
157  } else if (cinfo->global_state != CSTATE_WRCOEFS)
158    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
159  /* Perform any remaining passes */
160  while (! cinfo->master->is_last_pass) {
161    (*cinfo->master->prepare_for_pass) (cinfo);
162    for (iMCU_row = 0; iMCU_row < cinfo->total_iMCU_rows; iMCU_row++) {
163      if (cinfo->progress != NULL) {
164	cinfo->progress->pass_counter = (long) iMCU_row;
165	cinfo->progress->pass_limit = (long) cinfo->total_iMCU_rows;
166	(*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
167      }
168      /* We bypass the main controller and invoke coef controller directly;
169       * all work is being done from the coefficient buffer.
170       */
171      if (! (*cinfo->coef->compress_data) (cinfo, (JSAMPIMAGE) NULL))
172	ERREXIT(cinfo, JERR_CANT_SUSPEND);
173    }
174    (*cinfo->master->finish_pass) (cinfo);
175  }
176  /* Write EOI, do final cleanup */
177  (*cinfo->marker->write_file_trailer) (cinfo);
178  (*cinfo->dest->term_destination) (cinfo);
179  /* We can use jpeg_abort to release memory and reset global_state */
180  jpeg_abort((j_common_ptr) cinfo);
181}
182
183
184/*
185 * Write a special marker.
186 * This is only recommended for writing COM or APPn markers.
187 * Must be called after jpeg_start_compress() and before
188 * first call to jpeg_write_scanlines() or jpeg_write_raw_data().
189 */
190
191GLOBAL(void)
192jpeg_write_marker (j_compress_ptr cinfo, int marker,
193		   const JOCTET *dataptr, unsigned int datalen)
194{
195  JMETHOD(void, write_marker_byte, (j_compress_ptr info, int val));
196
197  if (cinfo->next_scanline != 0 ||
198      (cinfo->global_state != CSTATE_SCANNING &&
199       cinfo->global_state != CSTATE_RAW_OK &&
200       cinfo->global_state != CSTATE_WRCOEFS))
201    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
202
203  (*cinfo->marker->write_marker_header) (cinfo, marker, datalen);
204  write_marker_byte = cinfo->marker->write_marker_byte;	/* copy for speed */
205  while (datalen--) {
206    (*write_marker_byte) (cinfo, *dataptr);
207    dataptr++;
208  }
209}
210
211/* Same, but piecemeal. */
212
213GLOBAL(void)
214jpeg_write_m_header (j_compress_ptr cinfo, int marker, unsigned int datalen)
215{
216  if (cinfo->next_scanline != 0 ||
217      (cinfo->global_state != CSTATE_SCANNING &&
218       cinfo->global_state != CSTATE_RAW_OK &&
219       cinfo->global_state != CSTATE_WRCOEFS))
220    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
221
222  (*cinfo->marker->write_marker_header) (cinfo, marker, datalen);
223}
224
225GLOBAL(void)
226jpeg_write_m_byte (j_compress_ptr cinfo, int val)
227{
228  (*cinfo->marker->write_marker_byte) (cinfo, val);
229}
230
231
232/*
233 * Alternate compression function: just write an abbreviated table file.
234 * Before calling this, all parameters and a data destination must be set up.
235 *
236 * To produce a pair of files containing abbreviated tables and abbreviated
237 * image data, one would proceed as follows:
238 *
239 *		initialize JPEG object
240 *		set JPEG parameters
241 *		set destination to table file
242 *		jpeg_write_tables(cinfo);
243 *		set destination to image file
244 *		jpeg_start_compress(cinfo, FALSE);
245 *		write data...
246 *		jpeg_finish_compress(cinfo);
247 *
248 * jpeg_write_tables has the side effect of marking all tables written
249 * (same as jpeg_suppress_tables(..., TRUE)).  Thus a subsequent start_compress
250 * will not re-emit the tables unless it is passed write_all_tables=TRUE.
251 */
252
253GLOBAL(void)
254jpeg_write_tables (j_compress_ptr cinfo)
255{
256  if (cinfo->global_state != CSTATE_START)
257    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
258
259  /* (Re)initialize error mgr and destination modules */
260  (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
261  (*cinfo->dest->init_destination) (cinfo);
262  /* Initialize the marker writer ... bit of a crock to do it here. */
263  jinit_marker_writer(cinfo);
264  /* Write them tables! */
265  (*cinfo->marker->write_tables_only) (cinfo);
266  /* And clean up. */
267  (*cinfo->dest->term_destination) (cinfo);
268  /*
269   * In library releases up through v6a, we called jpeg_abort() here to free
270   * any working memory allocated by the destination manager and marker
271   * writer.  Some applications had a problem with that: they allocated space
272   * of their own from the library memory manager, and didn't want it to go
273   * away during write_tables.  So now we do nothing.  This will cause a
274   * memory leak if an app calls write_tables repeatedly without doing a full
275   * compression cycle or otherwise resetting the JPEG object.  However, that
276   * seems less bad than unexpectedly freeing memory in the normal case.
277   * An app that prefers the old behavior can call jpeg_abort for itself after
278   * each call to jpeg_write_tables().
279   */
280}