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 
30 GLOBAL(void)
jpeg_CreateCompress(j_compress_ptr cinfo,int version,size_t structsize)31 jpeg_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     cinfo->q_scale_factor[i] = 100;
70   }
71 
72   for (i = 0; i < NUM_HUFF_TBLS; i++) {
73     cinfo->dc_huff_tbl_ptrs[i] = NULL;
74     cinfo->ac_huff_tbl_ptrs[i] = NULL;
75   }
76 
77   /* Must do it here for emit_dqt in case jpeg_write_tables is used */
78   cinfo->block_size = DCTSIZE;
79   cinfo->natural_order = jpeg_natural_order;
80   cinfo->lim_Se = DCTSIZE2-1;
81 
82   cinfo->script_space = NULL;
83 
84   cinfo->input_gamma = 1.0;	/* in case application forgets */
85 
86   /* OK, I'm ready */
87   cinfo->global_state = CSTATE_START;
88 }
89 
90 
91 /*
92  * Destruction of a JPEG compression object
93  */
94 
95 GLOBAL(void)
jpeg_destroy_compress(j_compress_ptr cinfo)96 jpeg_destroy_compress (j_compress_ptr cinfo)
97 {
98   jpeg_destroy((j_common_ptr) cinfo); /* use common routine */
99 }
100 
101 
102 /*
103  * Abort processing of a JPEG compression operation,
104  * but don't destroy the object itself.
105  */
106 
107 GLOBAL(void)
jpeg_abort_compress(j_compress_ptr cinfo)108 jpeg_abort_compress (j_compress_ptr cinfo)
109 {
110   jpeg_abort((j_common_ptr) cinfo); /* use common routine */
111 }
112 
113 
114 /*
115  * Forcibly suppress or un-suppress all quantization and Huffman tables.
116  * Marks all currently defined tables as already written (if suppress)
117  * or not written (if !suppress).  This will control whether they get emitted
118  * by a subsequent jpeg_start_compress call.
119  *
120  * This routine is exported for use by applications that want to produce
121  * abbreviated JPEG datastreams.  It logically belongs in jcparam.c, but
122  * since it is called by jpeg_start_compress, we put it here --- otherwise
123  * jcparam.o would be linked whether the application used it or not.
124  */
125 
126 GLOBAL(void)
jpeg_suppress_tables(j_compress_ptr cinfo,boolean suppress)127 jpeg_suppress_tables (j_compress_ptr cinfo, boolean suppress)
128 {
129   int i;
130   JQUANT_TBL * qtbl;
131   JHUFF_TBL * htbl;
132 
133   for (i = 0; i < NUM_QUANT_TBLS; i++) {
134     if ((qtbl = cinfo->quant_tbl_ptrs[i]) != NULL)
135       qtbl->sent_table = suppress;
136   }
137 
138   for (i = 0; i < NUM_HUFF_TBLS; i++) {
139     if ((htbl = cinfo->dc_huff_tbl_ptrs[i]) != NULL)
140       htbl->sent_table = suppress;
141     if ((htbl = cinfo->ac_huff_tbl_ptrs[i]) != NULL)
142       htbl->sent_table = suppress;
143   }
144 }
145 
146 
147 /*
148  * Finish JPEG compression.
149  *
150  * If a multipass operating mode was selected, this may do a great deal of
151  * work including most of the actual output.
152  */
153 
154 GLOBAL(void)
jpeg_finish_compress(j_compress_ptr cinfo)155 jpeg_finish_compress (j_compress_ptr cinfo)
156 {
157   JDIMENSION iMCU_row;
158 
159   if (cinfo->global_state == CSTATE_SCANNING ||
160       cinfo->global_state == CSTATE_RAW_OK) {
161     /* Terminate first pass */
162     if (cinfo->next_scanline < cinfo->image_height)
163       ERREXIT(cinfo, JERR_TOO_LITTLE_DATA);
164     (*cinfo->master->finish_pass) (cinfo);
165   } else if (cinfo->global_state != CSTATE_WRCOEFS)
166     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
167   /* Perform any remaining passes */
168   while (! cinfo->master->is_last_pass) {
169     (*cinfo->master->prepare_for_pass) (cinfo);
170     for (iMCU_row = 0; iMCU_row < cinfo->total_iMCU_rows; iMCU_row++) {
171       if (cinfo->progress != NULL) {
172 	cinfo->progress->pass_counter = (long) iMCU_row;
173 	cinfo->progress->pass_limit = (long) cinfo->total_iMCU_rows;
174 	(*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
175       }
176       /* We bypass the main controller and invoke coef controller directly;
177        * all work is being done from the coefficient buffer.
178        */
179       if (! (*cinfo->coef->compress_data) (cinfo, (JSAMPIMAGE) NULL))
180 	ERREXIT(cinfo, JERR_CANT_SUSPEND);
181     }
182     (*cinfo->master->finish_pass) (cinfo);
183   }
184   /* Write EOI, do final cleanup */
185   (*cinfo->marker->write_file_trailer) (cinfo);
186   (*cinfo->dest->term_destination) (cinfo);
187   /* We can use jpeg_abort to release memory and reset global_state */
188   jpeg_abort((j_common_ptr) cinfo);
189 }
190 
191 
192 /*
193  * Write a special marker.
194  * This is only recommended for writing COM or APPn markers.
195  * Must be called after jpeg_start_compress() and before
196  * first call to jpeg_write_scanlines() or jpeg_write_raw_data().
197  */
198 
199 GLOBAL(void)
jpeg_write_marker(j_compress_ptr cinfo,int marker,const JOCTET * dataptr,unsigned int datalen)200 jpeg_write_marker (j_compress_ptr cinfo, int marker,
201 		   const JOCTET *dataptr, unsigned int datalen)
202 {
203   JMETHOD(void, write_marker_byte, (j_compress_ptr info, int val));
204 
205   if (cinfo->next_scanline != 0 ||
206       (cinfo->global_state != CSTATE_SCANNING &&
207        cinfo->global_state != CSTATE_RAW_OK &&
208        cinfo->global_state != CSTATE_WRCOEFS))
209     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
210 
211   (*cinfo->marker->write_marker_header) (cinfo, marker, datalen);
212   write_marker_byte = cinfo->marker->write_marker_byte;	/* copy for speed */
213   while (datalen--) {
214     (*write_marker_byte) (cinfo, *dataptr);
215     dataptr++;
216   }
217 }
218 
219 /* Same, but piecemeal. */
220 
221 GLOBAL(void)
jpeg_write_m_header(j_compress_ptr cinfo,int marker,unsigned int datalen)222 jpeg_write_m_header (j_compress_ptr cinfo, int marker, unsigned int datalen)
223 {
224   if (cinfo->next_scanline != 0 ||
225       (cinfo->global_state != CSTATE_SCANNING &&
226        cinfo->global_state != CSTATE_RAW_OK &&
227        cinfo->global_state != CSTATE_WRCOEFS))
228     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
229 
230   (*cinfo->marker->write_marker_header) (cinfo, marker, datalen);
231 }
232 
233 GLOBAL(void)
jpeg_write_m_byte(j_compress_ptr cinfo,int val)234 jpeg_write_m_byte (j_compress_ptr cinfo, int val)
235 {
236   (*cinfo->marker->write_marker_byte) (cinfo, val);
237 }
238 
239 
240 /*
241  * Alternate compression function: just write an abbreviated table file.
242  * Before calling this, all parameters and a data destination must be set up.
243  *
244  * To produce a pair of files containing abbreviated tables and abbreviated
245  * image data, one would proceed as follows:
246  *
247  *		initialize JPEG object
248  *		set JPEG parameters
249  *		set destination to table file
250  *		jpeg_write_tables(cinfo);
251  *		set destination to image file
252  *		jpeg_start_compress(cinfo, FALSE);
253  *		write data...
254  *		jpeg_finish_compress(cinfo);
255  *
256  * jpeg_write_tables has the side effect of marking all tables written
257  * (same as jpeg_suppress_tables(..., TRUE)).  Thus a subsequent start_compress
258  * will not re-emit the tables unless it is passed write_all_tables=TRUE.
259  */
260 
261 GLOBAL(void)
jpeg_write_tables(j_compress_ptr cinfo)262 jpeg_write_tables (j_compress_ptr cinfo)
263 {
264   if (cinfo->global_state != CSTATE_START)
265     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
266 
267   /* (Re)initialize error mgr and destination modules */
268   (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
269   (*cinfo->dest->init_destination) (cinfo);
270   /* Initialize the marker writer ... bit of a crock to do it here. */
271   jinit_marker_writer(cinfo);
272   /* Write them tables! */
273   (*cinfo->marker->write_tables_only) (cinfo);
274   /* And clean up. */
275   (*cinfo->dest->term_destination) (cinfo);
276   /*
277    * In library releases up through v6a, we called jpeg_abort() here to free
278    * any working memory allocated by the destination manager and marker
279    * writer.  Some applications had a problem with that: they allocated space
280    * of their own from the library memory manager, and didn't want it to go
281    * away during write_tables.  So now we do nothing.  This will cause a
282    * memory leak if an app calls write_tables repeatedly without doing a full
283    * compression cycle or otherwise resetting the JPEG object.  However, that
284    * seems less bad than unexpectedly freeing memory in the normal case.
285    * An app that prefers the old behavior can call jpeg_abort for itself after
286    * each call to jpeg_write_tables().
287    */
288 }
289