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