jdk
284 строки · 9.1 Кб
1/*
2* reserved comment block
3* DO NOT REMOVE OR ALTER!
4*/
5/*
6* jcapimin.c
7*
8* Copyright (C) 1994-1998, Thomas G. Lane.
9* This file is part of the Independent JPEG Group's software.
10* For conditions of distribution and use, see the accompanying README 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{
36int i;
37
38/* Guard against version mismatches between library and caller. */
39cinfo->mem = NULL; /* so jpeg_destroy knows mem mgr not called */
40if (version != JPEG_LIB_VERSION)
41ERREXIT2(cinfo, JERR_BAD_LIB_VERSION, JPEG_LIB_VERSION, version);
42if (structsize != SIZEOF(struct jpeg_compress_struct))
43ERREXIT2(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{
53struct jpeg_error_mgr * err = cinfo->err;
54void * client_data = cinfo->client_data; /* ignore Purify complaint here */
55MEMZERO(cinfo, SIZEOF(struct jpeg_compress_struct));
56cinfo->err = err;
57cinfo->client_data = client_data;
58}
59cinfo->is_decompressor = FALSE;
60
61/* Initialize a memory manager instance for this object */
62jinit_memory_mgr((j_common_ptr) cinfo);
63
64/* Zero out pointers to permanent structures. */
65cinfo->progress = NULL;
66cinfo->dest = NULL;
67
68cinfo->comp_info = NULL;
69
70for (i = 0; i < NUM_QUANT_TBLS; i++)
71cinfo->quant_tbl_ptrs[i] = NULL;
72
73for (i = 0; i < NUM_HUFF_TBLS; i++) {
74cinfo->dc_huff_tbl_ptrs[i] = NULL;
75cinfo->ac_huff_tbl_ptrs[i] = NULL;
76}
77
78cinfo->script_space = NULL;
79
80cinfo->input_gamma = 1.0; /* in case application forgets */
81
82/* OK, I'm ready */
83cinfo->global_state = CSTATE_START;
84}
85
86
87/*
88* Destruction of a JPEG compression object
89*/
90
91GLOBAL(void)
92jpeg_destroy_compress (j_compress_ptr cinfo)
93{
94jpeg_destroy((j_common_ptr) cinfo); /* use common routine */
95}
96
97
98/*
99* Abort processing of a JPEG compression operation,
100* but don't destroy the object itself.
101*/
102
103GLOBAL(void)
104jpeg_abort_compress (j_compress_ptr cinfo)
105{
106jpeg_abort((j_common_ptr) cinfo); /* use common routine */
107}
108
109
110/*
111* Forcibly suppress or un-suppress all quantization and Huffman tables.
112* Marks all currently defined tables as already written (if suppress)
113* or not written (if !suppress). This will control whether they get emitted
114* by a subsequent jpeg_start_compress call.
115*
116* This routine is exported for use by applications that want to produce
117* abbreviated JPEG datastreams. It logically belongs in jcparam.c, but
118* since it is called by jpeg_start_compress, we put it here --- otherwise
119* jcparam.o would be linked whether the application used it or not.
120*/
121
122GLOBAL(void)
123jpeg_suppress_tables (j_compress_ptr cinfo, boolean suppress)
124{
125int i;
126JQUANT_TBL * qtbl;
127JHUFF_TBL * htbl;
128
129for (i = 0; i < NUM_QUANT_TBLS; i++) {
130if ((qtbl = cinfo->quant_tbl_ptrs[i]) != NULL)
131qtbl->sent_table = suppress;
132}
133
134for (i = 0; i < NUM_HUFF_TBLS; i++) {
135if ((htbl = cinfo->dc_huff_tbl_ptrs[i]) != NULL)
136htbl->sent_table = suppress;
137if ((htbl = cinfo->ac_huff_tbl_ptrs[i]) != NULL)
138htbl->sent_table = suppress;
139}
140}
141
142
143/*
144* Finish JPEG compression.
145*
146* If a multipass operating mode was selected, this may do a great deal of
147* work including most of the actual output.
148*/
149
150GLOBAL(void)
151jpeg_finish_compress (j_compress_ptr cinfo)
152{
153JDIMENSION iMCU_row;
154
155if (cinfo->global_state == CSTATE_SCANNING ||
156cinfo->global_state == CSTATE_RAW_OK) {
157/* Terminate first pass */
158if (cinfo->next_scanline < cinfo->image_height)
159ERREXIT(cinfo, JERR_TOO_LITTLE_DATA);
160(*cinfo->master->finish_pass) (cinfo);
161} else if (cinfo->global_state != CSTATE_WRCOEFS)
162ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
163/* Perform any remaining passes */
164while (! cinfo->master->is_last_pass) {
165(*cinfo->master->prepare_for_pass) (cinfo);
166for (iMCU_row = 0; iMCU_row < cinfo->total_iMCU_rows; iMCU_row++) {
167if (cinfo->progress != NULL) {
168cinfo->progress->pass_counter = (long) iMCU_row;
169cinfo->progress->pass_limit = (long) cinfo->total_iMCU_rows;
170(*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
171}
172/* We bypass the main controller and invoke coef controller directly;
173* all work is being done from the coefficient buffer.
174*/
175if (! (*cinfo->coef->compress_data) (cinfo, (JSAMPIMAGE) NULL))
176ERREXIT(cinfo, JERR_CANT_SUSPEND);
177}
178(*cinfo->master->finish_pass) (cinfo);
179}
180/* Write EOI, do final cleanup */
181(*cinfo->marker->write_file_trailer) (cinfo);
182(*cinfo->dest->term_destination) (cinfo);
183/* We can use jpeg_abort to release memory and reset global_state */
184jpeg_abort((j_common_ptr) cinfo);
185}
186
187
188/*
189* Write a special marker.
190* This is only recommended for writing COM or APPn markers.
191* Must be called after jpeg_start_compress() and before
192* first call to jpeg_write_scanlines() or jpeg_write_raw_data().
193*/
194
195GLOBAL(void)
196jpeg_write_marker (j_compress_ptr cinfo, int marker,
197const JOCTET *dataptr, unsigned int datalen)
198{
199JMETHOD(void, write_marker_byte, (j_compress_ptr info, int val));
200
201if (cinfo->next_scanline != 0 ||
202(cinfo->global_state != CSTATE_SCANNING &&
203cinfo->global_state != CSTATE_RAW_OK &&
204cinfo->global_state != CSTATE_WRCOEFS))
205ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
206
207(*cinfo->marker->write_marker_header) (cinfo, marker, datalen);
208write_marker_byte = cinfo->marker->write_marker_byte; /* copy for speed */
209while (datalen--) {
210(*write_marker_byte) (cinfo, *dataptr);
211dataptr++;
212}
213}
214
215/* Same, but piecemeal. */
216
217GLOBAL(void)
218jpeg_write_m_header (j_compress_ptr cinfo, int marker, unsigned int datalen)
219{
220if (cinfo->next_scanline != 0 ||
221(cinfo->global_state != CSTATE_SCANNING &&
222cinfo->global_state != CSTATE_RAW_OK &&
223cinfo->global_state != CSTATE_WRCOEFS))
224ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
225
226(*cinfo->marker->write_marker_header) (cinfo, marker, datalen);
227}
228
229GLOBAL(void)
230jpeg_write_m_byte (j_compress_ptr cinfo, int val)
231{
232(*cinfo->marker->write_marker_byte) (cinfo, val);
233}
234
235
236/*
237* Alternate compression function: just write an abbreviated table file.
238* Before calling this, all parameters and a data destination must be set up.
239*
240* To produce a pair of files containing abbreviated tables and abbreviated
241* image data, one would proceed as follows:
242*
243* initialize JPEG object
244* set JPEG parameters
245* set destination to table file
246* jpeg_write_tables(cinfo);
247* set destination to image file
248* jpeg_start_compress(cinfo, FALSE);
249* write data...
250* jpeg_finish_compress(cinfo);
251*
252* jpeg_write_tables has the side effect of marking all tables written
253* (same as jpeg_suppress_tables(..., TRUE)). Thus a subsequent start_compress
254* will not re-emit the tables unless it is passed write_all_tables=TRUE.
255*/
256
257GLOBAL(void)
258jpeg_write_tables (j_compress_ptr cinfo)
259{
260if (cinfo->global_state != CSTATE_START)
261ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
262
263/* (Re)initialize error mgr and destination modules */
264(*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
265(*cinfo->dest->init_destination) (cinfo);
266/* Initialize the marker writer ... bit of a crock to do it here. */
267jinit_marker_writer(cinfo);
268/* Write them tables! */
269(*cinfo->marker->write_tables_only) (cinfo);
270/* And clean up. */
271(*cinfo->dest->term_destination) (cinfo);
272/*
273* In library releases up through v6a, we called jpeg_abort() here to free
274* any working memory allocated by the destination manager and marker
275* writer. Some applications had a problem with that: they allocated space
276* of their own from the library memory manager, and didn't want it to go
277* away during write_tables. So now we do nothing. This will cause a
278* memory leak if an app calls write_tables repeatedly without doing a full
279* compression cycle or otherwise resetting the JPEG object. However, that
280* seems less bad than unexpectedly freeing memory in the normal case.
281* An app that prefers the old behavior can call jpeg_abort for itself after
282* each call to jpeg_write_tables().
283*/
284}
285