ReactOS  0.4.15-dev-1070-ge1a01de
jdatadst.c
Go to the documentation of this file.
1 /*
2  * jdatadst.c
3  *
4  * Copyright (C) 1994-1996, Thomas G. Lane.
5  * Modified 2009-2019 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 compression data destination routines for the case of
10  * emitting JPEG data to memory or to a file (or any stdio stream).
11  * While these routines are sufficient for most applications,
12  * some will want to use a different destination manager.
13  * IMPORTANT: we assume that fwrite() will correctly transcribe an array of
14  * JOCTETs into 8-bit-wide elements on external storage. If char is wider
15  * than 8 bits on your machine, you may need to do some tweaking.
16  */
17 
18 /* this is not a core library module, so it doesn't define JPEG_INTERNALS */
19 #include "jinclude.h"
20 #include "jpeglib.h"
21 #include "jerror.h"
22 
23 #ifndef HAVE_STDLIB_H /* <stdlib.h> should declare malloc(),free() */
24 extern void * malloc JPP((size_t size));
25 extern void free JPP((void *ptr));
26 #endif
27 
28 
29 /* Expanded data destination object for stdio output */
30 
31 typedef struct {
32  struct jpeg_destination_mgr pub; /* public fields */
33 
34  FILE * outfile; /* target stream */
35  JOCTET * buffer; /* start of buffer */
37 
39 
40 #define OUTPUT_BUF_SIZE 4096 /* choose an efficiently fwrite'able size */
41 
42 
43 /* Expanded data destination object for memory output */
44 
45 typedef struct {
46  struct jpeg_destination_mgr pub; /* public fields */
47 
48  unsigned char ** outbuffer; /* target buffer */
49  size_t * outsize;
50  unsigned char * newbuffer; /* newly allocated buffer */
51  JOCTET * buffer; /* start of buffer */
52  size_t bufsize;
54 
56 
57 
58 /*
59  * Initialize destination --- called by jpeg_start_compress
60  * before any data is actually written.
61  */
62 
63 METHODDEF(void)
65 {
66  my_dest_ptr dest = (my_dest_ptr) cinfo->dest;
67 
68  /* Allocate the output buffer --- it will be released when done with image */
69  dest->buffer = (JOCTET *) (*cinfo->mem->alloc_small)
71 
72  dest->pub.next_output_byte = dest->buffer;
73  dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
74 }
75 
76 METHODDEF(void)
78 {
79  /* no work necessary here */
80 }
81 
82 
83 /*
84  * Empty the output buffer --- called whenever buffer fills up.
85  *
86  * In typical applications, this should write the entire output buffer
87  * (ignoring the current state of next_output_byte & free_in_buffer),
88  * reset the pointer & count to the start of the buffer, and return TRUE
89  * indicating that the buffer has been dumped.
90  *
91  * In applications that need to be able to suspend compression due to output
92  * overrun, a FALSE return indicates that the buffer cannot be emptied now.
93  * In this situation, the compressor will return to its caller (possibly with
94  * an indication that it has not accepted all the supplied scanlines). The
95  * application should resume compression after it has made more room in the
96  * output buffer. Note that there are substantial restrictions on the use of
97  * suspension --- see the documentation.
98  *
99  * When suspending, the compressor will back up to a convenient restart point
100  * (typically the start of the current MCU). next_output_byte & free_in_buffer
101  * indicate where the restart point will be if the current call returns FALSE.
102  * Data beyond this point will be regenerated after resumption, so do not
103  * write it out when emptying the buffer externally.
104  */
105 
106 METHODDEF(boolean)
108 {
109  my_dest_ptr dest = (my_dest_ptr) cinfo->dest;
110 
111  if (JFWRITE(dest->outfile, dest->buffer, OUTPUT_BUF_SIZE) !=
113  ERREXIT(cinfo, JERR_FILE_WRITE);
114 
115  dest->pub.next_output_byte = dest->buffer;
116  dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
117 
118  return TRUE;
119 }
120 
121 METHODDEF(boolean)
123 {
124  size_t nextsize;
125  JOCTET * nextbuffer;
126  my_mem_dest_ptr dest = (my_mem_dest_ptr) cinfo->dest;
127 
128  /* Try to allocate new buffer with double size */
129  nextsize = dest->bufsize * 2;
130  nextbuffer = (JOCTET *) malloc(nextsize);
131 
132  if (nextbuffer == NULL)
133  ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, 11);
134 
135  MEMCOPY(nextbuffer, dest->buffer, dest->bufsize);
136 
137  if (dest->newbuffer != NULL)
138  free(dest->newbuffer);
139 
140  dest->newbuffer = nextbuffer;
141 
142  dest->pub.next_output_byte = nextbuffer + dest->bufsize;
143  dest->pub.free_in_buffer = dest->bufsize;
144 
145  dest->buffer = nextbuffer;
146  dest->bufsize = nextsize;
147 
148  return TRUE;
149 }
150 
151 
152 /*
153  * Terminate destination --- called by jpeg_finish_compress
154  * after all data has been written. Usually needs to flush buffer.
155  *
156  * NB: *not* called by jpeg_abort or jpeg_destroy; surrounding
157  * application must deal with any cleanup that should happen even
158  * for error exit.
159  */
160 
161 METHODDEF(void)
163 {
164  my_dest_ptr dest = (my_dest_ptr) cinfo->dest;
165  size_t datacount = OUTPUT_BUF_SIZE - dest->pub.free_in_buffer;
166 
167  /* Write any data remaining in the buffer */
168  if (datacount > 0) {
169  if (JFWRITE(dest->outfile, dest->buffer, datacount) != datacount)
170  ERREXIT(cinfo, JERR_FILE_WRITE);
171  }
172  JFFLUSH(dest->outfile);
173  /* Make sure we wrote the output file OK */
174  if (JFERROR(dest->outfile))
175  ERREXIT(cinfo, JERR_FILE_WRITE);
176 }
177 
178 METHODDEF(void)
180 {
181  my_mem_dest_ptr dest = (my_mem_dest_ptr) cinfo->dest;
182 
183  *dest->outbuffer = dest->buffer;
184  *dest->outsize = dest->bufsize - dest->pub.free_in_buffer;
185 }
186 
187 
188 /*
189  * Prepare for output to a stdio stream.
190  * The caller must have already opened the stream, and is responsible
191  * for closing it after finishing compression.
192  */
193 
194 GLOBAL(void)
196 {
198 
199  /* The destination object is made permanent so that multiple JPEG images
200  * can be written to the same file without re-executing jpeg_stdio_dest.
201  * This makes it dangerous to use this manager and a different destination
202  * manager serially with the same JPEG object, because their private object
203  * sizes may be different. Caveat programmer.
204  */
205  if (cinfo->dest == NULL) { /* first time for this JPEG object? */
206  cinfo->dest = (struct jpeg_destination_mgr *) (*cinfo->mem->alloc_small)
208  }
209 
210  dest = (my_dest_ptr) cinfo->dest;
211  dest->pub.init_destination = init_destination;
212  dest->pub.empty_output_buffer = empty_output_buffer;
213  dest->pub.term_destination = term_destination;
214  dest->outfile = outfile;
215 }
216 
217 
218 /*
219  * Prepare for output to a memory buffer.
220  * The caller may supply an own initial buffer with appropriate size.
221  * Otherwise, or when the actual data output exceeds the given size,
222  * the library adapts the buffer size as necessary.
223  * The standard library functions malloc/free are used for allocating
224  * larger memory, so the buffer is available to the application after
225  * finishing compression, and then the application is responsible for
226  * freeing the requested memory.
227  * Note: An initial buffer supplied by the caller is expected to be
228  * managed by the application. The library does not free such buffer
229  * when allocating a larger buffer.
230  */
231 
232 GLOBAL(void)
234  unsigned char ** outbuffer, size_t * outsize)
235 {
237 
238  if (outbuffer == NULL || outsize == NULL) /* sanity check */
239  ERREXIT(cinfo, JERR_BUFFER_SIZE);
240 
241  /* The destination object is made permanent so that multiple JPEG images
242  * can be written to the same buffer without re-executing jpeg_mem_dest.
243  */
244  if (cinfo->dest == NULL) { /* first time for this JPEG object? */
245  cinfo->dest = (struct jpeg_destination_mgr *) (*cinfo->mem->alloc_small)
247  }
248 
249  dest = (my_mem_dest_ptr) cinfo->dest;
250  dest->pub.init_destination = init_mem_destination;
251  dest->pub.empty_output_buffer = empty_mem_output_buffer;
252  dest->pub.term_destination = term_mem_destination;
253  dest->outbuffer = outbuffer;
254  dest->outsize = outsize;
255  dest->newbuffer = NULL;
256 
257  if (*outbuffer == NULL || *outsize == 0) {
258  /* Allocate initial buffer */
259  dest->newbuffer = *outbuffer = (unsigned char *) malloc(OUTPUT_BUF_SIZE);
260  if (dest->newbuffer == NULL)
261  ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, 10);
263  }
264 
265  dest->pub.next_output_byte = dest->buffer = *outbuffer;
266  dest->pub.free_in_buffer = dest->bufsize = *outsize;
267 }
term_mem_destination(j_compress_ptr cinfo)
Definition: jdatadst.c:179
unsigned char ** outbuffer
Definition: jpeglib.h:980
#define ERREXIT(msg)
Definition: rdjpgcom.c:72
my_destination_mgr * my_dest_ptr
Definition: jdatadst.c:38
#define TRUE
Definition: types.h:120
#define free
Definition: debug_ros.c:5
struct jpeg_common_struct * j_common_ptr
Definition: jpeglib.h:284
static FILE * outfile
Definition: wrjpgcom.c:81
jpeg_stdio_dest(j_compress_ptr cinfo, FILE *outfile)
Definition: jdatadst.c:195
jpeg_mem_dest(j_compress_ptr cinfo, unsigned char **outbuffer, size_t *outsize)
Definition: jdatadst.c:233
my_mem_destination_mgr * my_mem_dest_ptr
Definition: jdatadst.c:55
#define JFERROR(file)
Definition: jinclude.h:97
unsigned char * newbuffer
Definition: jdatadst.c:50
#define JFWRITE(file, buf, sizeofbuf)
Definition: jinclude.h:94
#define SIZEOF(_ar)
Definition: calc.h:97
#define JPOOL_IMAGE
Definition: jpeglib.h:808
static PVOID ptr
Definition: dispmode.c:27
term_destination(j_compress_ptr cinfo)
Definition: jdatadst.c:162
#define JFFLUSH(file)
Definition: jinclude.h:96
smooth NULL
Definition: ftsmooth.c:416
#define MEMCOPY(dest, src, size)
Definition: jinclude.h:69
void *malloc JPP((size_t size))
__kernel_size_t size_t
Definition: linux.h:237
GLsizeiptr size
Definition: glext.h:5919
unsigned char size_t * outsize
Definition: jpeglib.h:980
if(!(yy_init))
Definition: macro.lex.yy.c:714
#define ERREXIT1(cinfo, code, p1)
Definition: jerror.h:212
init_destination(j_compress_ptr cinfo)
Definition: jdatadst.c:64
#define GLOBAL(type)
Definition: jmorecfg.h:291
#define METHODDEF(type)
Definition: jmorecfg.h:287
empty_output_buffer(j_compress_ptr cinfo)
Definition: jdatadst.c:107
JOCTET * buffer
Definition: jdatadst.c:35
init_mem_destination(j_compress_ptr cinfo)
Definition: jdatadst.c:77
#define JPOOL_PERMANENT
Definition: jpeglib.h:807
char JOCTET
Definition: jmorecfg.h:167
#define malloc
Definition: debug_ros.c:4
static char * dest
Definition: rtl.c:135
#define OUTPUT_BUF_SIZE
Definition: jdatadst.c:40
empty_mem_output_buffer(j_compress_ptr cinfo)
Definition: jdatadst.c:122
unsigned char ** outbuffer
Definition: jdatadst.c:48