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fixed bug in scaling images
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1 /////////////////////////////////////////////////////////////////////////////
2 // Name: imagjpeg.cpp
3 // Purpose: wxImage JPEG handler
4 // Author: Vaclav Slavik
5 // RCS-ID: $Id$
6 // Copyright: (c) Vaclav Slavik
7 // Licence: wxWindows licence
8 /////////////////////////////////////////////////////////////////////////////
9
10 #ifdef __GNUG__
11 #pragma implementation "imagjpeg.h"
12 #endif
13
14 // For compilers that support precompilation, includes "wx.h".
15 #include "wx/wxprec.h"
16
17 #ifdef __BORLANDC__
18 #pragma hdrstop
19 #endif
20
21 #include "wx/defs.h"
22
23 #if wxUSE_LIBJPEG
24
25 #include "wx/imagjpeg.h"
26 #include "wx/bitmap.h"
27 #include "wx/debug.h"
28 #include "wx/log.h"
29 #include "wx/app.h"
30 extern "C"
31 {
32 #include "jpeglib.h"
33 }
34 #include "wx/filefn.h"
35 #include "wx/wfstream.h"
36 #include "wx/intl.h"
37 #include "wx/module.h"
38
39 // For memcpy
40 #include <string.h>
41 // For JPEG library error handling
42 #include <setjmp.h>
43
44 #ifdef __SALFORDC__
45 #ifdef FAR
46 #undef FAR
47 #endif
48 #endif
49
50 #ifdef __WXMSW__
51 #include <windows.h>
52 #endif
53
54 //-----------------------------------------------------------------------------
55 // wxJPEGHandler
56 //-----------------------------------------------------------------------------
57
58 IMPLEMENT_DYNAMIC_CLASS(wxJPEGHandler,wxImageHandler)
59
60 #if wxUSE_STREAMS
61
62 //------------- JPEG Data Source Manager
63
64 #define JPEG_IO_BUFFER_SIZE 2048
65
66 typedef struct {
67 struct jpeg_source_mgr pub; /* public fields */
68
69 JOCTET* buffer; /* start of buffer */
70 wxInputStream *stream;
71 } my_source_mgr;
72
73 typedef my_source_mgr * my_src_ptr;
74
75 METHODDEF(void) my_init_source ( j_decompress_ptr WXUNUSED(cinfo) )
76 {
77 }
78
79 METHODDEF(boolean) my_fill_input_buffer ( j_decompress_ptr cinfo )
80 {
81 my_src_ptr src = (my_src_ptr) cinfo->src;
82
83 src->pub.next_input_byte = src->buffer;
84 src->pub.bytes_in_buffer = src->stream->Read(src->buffer, JPEG_IO_BUFFER_SIZE).LastRead();
85
86 if (src->pub.bytes_in_buffer == 0) // check for end-of-stream
87 {
88 // Insert a fake EOI marker
89 src->buffer[0] = 0xFF;
90 src->buffer[1] = JPEG_EOI;
91 src->pub.bytes_in_buffer = 2;
92 }
93 return TRUE;
94 }
95
96 METHODDEF(void) my_skip_input_data ( j_decompress_ptr cinfo, long num_bytes )
97 {
98 if (num_bytes > 0)
99 {
100 my_src_ptr src = (my_src_ptr) cinfo->src;
101
102 while (num_bytes > (long)src->pub.bytes_in_buffer)
103 {
104 num_bytes -= (long) src->pub.bytes_in_buffer;
105 src->pub.fill_input_buffer(cinfo);
106 }
107 src->pub.next_input_byte += (size_t) num_bytes;
108 src->pub.bytes_in_buffer -= (size_t) num_bytes;
109 }
110 }
111
112 METHODDEF(void) my_term_source ( j_decompress_ptr cinfo )
113 {
114 my_src_ptr src = (my_src_ptr) cinfo->src;
115
116 if (src->pub.bytes_in_buffer > 0)
117 src->stream->SeekI(-src->pub.bytes_in_buffer, wxFromCurrent);
118 delete[] src->buffer;
119 }
120
121 void jpeg_wxio_src( j_decompress_ptr cinfo, wxInputStream& infile )
122 {
123 my_src_ptr src;
124
125 if (cinfo->src == NULL) { /* first time for this JPEG object? */
126 cinfo->src = (struct jpeg_source_mgr *)
127 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
128 sizeof(my_source_mgr));
129 src = (my_src_ptr) cinfo->src;
130 }
131 src = (my_src_ptr) cinfo->src;
132 src->pub.bytes_in_buffer = 0; /* forces fill_input_buffer on first read */
133 src->buffer = new JOCTET[JPEG_IO_BUFFER_SIZE];
134 src->pub.next_input_byte = NULL; /* until buffer loaded */
135 src->stream = &infile;
136
137 src->pub.init_source = my_init_source;
138 src->pub.fill_input_buffer = my_fill_input_buffer;
139 src->pub.skip_input_data = my_skip_input_data;
140 src->pub.resync_to_restart = jpeg_resync_to_restart; /* use default method */
141 src->pub.term_source = my_term_source;
142 }
143
144
145 // JPEG error manager:
146
147 struct my_error_mgr {
148 struct jpeg_error_mgr pub; /* "public" fields */
149
150 jmp_buf setjmp_buffer; /* for return to caller */
151 };
152
153 typedef struct my_error_mgr * my_error_ptr;
154
155 /*
156 * Here's the routine that will replace the standard error_exit method:
157 */
158
159 METHODDEF(void)
160 my_error_exit (j_common_ptr cinfo)
161 {
162 /* cinfo->err really points to a my_error_mgr struct, so coerce pointer */
163 my_error_ptr myerr = (my_error_ptr) cinfo->err;
164
165 /* Always display the message. */
166 /* We could postpone this until after returning, if we chose. */
167 if (cinfo->err->output_message) (*cinfo->err->output_message) (cinfo);
168
169 /* Return control to the setjmp point */
170 longjmp(myerr->setjmp_buffer, 1);
171 }
172
173
174
175 bool wxJPEGHandler::LoadFile( wxImage *image, wxInputStream& stream, bool verbose, int WXUNUSED(index) )
176 {
177 struct jpeg_decompress_struct cinfo;
178 struct my_error_mgr jerr;
179 JSAMPARRAY tempbuf;
180 unsigned char *ptr;
181 unsigned stride;
182
183 image->Destroy();
184 cinfo.err = jpeg_std_error( &jerr.pub );
185 jerr.pub.error_exit = my_error_exit;
186
187 if (!verbose) cinfo.err->output_message=NULL;
188
189 /* Establish the setjmp return context for my_error_exit to use. */
190 if (setjmp(jerr.setjmp_buffer)) {
191 /* If we get here, the JPEG code has signaled an error.
192 * We need to clean up the JPEG object, close the input file, and return.
193 */
194 if (verbose)
195 wxLogError(_("JPEG: Couldn't load - file is probably corrupted."));
196 jpeg_destroy_decompress(&cinfo);
197 if (image->Ok()) image->Destroy();
198 return FALSE;
199 }
200
201 jpeg_create_decompress( &cinfo );
202 jpeg_wxio_src( &cinfo, stream );
203 jpeg_read_header( &cinfo, TRUE );
204 cinfo.out_color_space = JCS_RGB;
205 jpeg_start_decompress( &cinfo );
206
207 image->Create( cinfo.image_width, cinfo.image_height );
208 if (!image->Ok()) {
209 jpeg_finish_decompress( &cinfo );
210 jpeg_destroy_decompress( &cinfo );
211 return FALSE;
212 }
213 image->SetMask( FALSE );
214 ptr = image->GetData();
215 stride = cinfo.output_width * 3;
216 tempbuf = (*cinfo.mem->alloc_sarray)
217 ((j_common_ptr) &cinfo, JPOOL_IMAGE, stride, 1 );
218
219 while ( cinfo.output_scanline < cinfo.output_height ) {
220 jpeg_read_scanlines( &cinfo, tempbuf, 1 );
221 memcpy( ptr, tempbuf[0], stride );
222 ptr += stride;
223 }
224 jpeg_finish_decompress( &cinfo );
225 jpeg_destroy_decompress( &cinfo );
226 return TRUE;
227 }
228
229
230
231
232
233 typedef struct {
234 struct jpeg_destination_mgr pub;
235
236 wxOutputStream *stream;
237 JOCTET * buffer;
238 } my_destination_mgr;
239
240 typedef my_destination_mgr * my_dest_ptr;
241
242 #define OUTPUT_BUF_SIZE 4096 /* choose an efficiently fwrite'able size */
243
244 METHODDEF(void) init_destination (j_compress_ptr cinfo)
245 {
246 my_dest_ptr dest = (my_dest_ptr) cinfo->dest;
247
248 /* Allocate the output buffer --- it will be released when done with image */
249 dest->buffer = (JOCTET *)
250 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
251 OUTPUT_BUF_SIZE * sizeof(JOCTET));
252 dest->pub.next_output_byte = dest->buffer;
253 dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
254 }
255
256 METHODDEF(boolean) empty_output_buffer (j_compress_ptr cinfo)
257 {
258 my_dest_ptr dest = (my_dest_ptr) cinfo->dest;
259
260 dest->stream->Write(dest->buffer, OUTPUT_BUF_SIZE);
261 dest->pub.next_output_byte = dest->buffer;
262 dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
263 return TRUE;
264 }
265
266 METHODDEF(void) term_destination (j_compress_ptr cinfo)
267 {
268 my_dest_ptr dest = (my_dest_ptr) cinfo->dest;
269 size_t datacount = OUTPUT_BUF_SIZE - dest->pub.free_in_buffer;
270 /* Write any data remaining in the buffer */
271 if (datacount > 0)
272 dest->stream->Write(dest->buffer, datacount);
273 }
274
275 GLOBAL(void) jpeg_wxio_dest (j_compress_ptr cinfo, wxOutputStream& outfile)
276 {
277 my_dest_ptr dest;
278
279 if (cinfo->dest == NULL) { /* first time for this JPEG object? */
280 cinfo->dest = (struct jpeg_destination_mgr *)
281 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
282 sizeof(my_destination_mgr));
283 }
284
285 dest = (my_dest_ptr) cinfo->dest;
286 dest->pub.init_destination = init_destination;
287 dest->pub.empty_output_buffer = empty_output_buffer;
288 dest->pub.term_destination = term_destination;
289 dest->stream = &outfile;
290 }
291
292 bool wxJPEGHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool verbose )
293 {
294 struct jpeg_compress_struct cinfo;
295 struct my_error_mgr jerr;
296 JSAMPROW row_pointer[1]; /* pointer to JSAMPLE row[s] */
297 JSAMPLE *image_buffer;
298 int stride; /* physical row width in image buffer */
299
300 cinfo.err = jpeg_std_error(&jerr.pub);
301 jerr.pub.error_exit = my_error_exit;
302
303 if (!verbose) cinfo.err->output_message=NULL;
304
305 /* Establish the setjmp return context for my_error_exit to use. */
306 if (setjmp(jerr.setjmp_buffer))
307 {
308 /* If we get here, the JPEG code has signaled an error.
309 * We need to clean up the JPEG object, close the input file, and return.
310 */
311 if (verbose)
312 wxLogError(_("JPEG: Couldn't save image."));
313 jpeg_destroy_compress(&cinfo);
314 return FALSE;
315 }
316
317 jpeg_create_compress(&cinfo);
318 jpeg_wxio_dest(&cinfo, stream);
319
320 cinfo.image_width = image->GetWidth();
321 cinfo.image_height = image->GetHeight();
322 cinfo.input_components = 3;
323 cinfo.in_color_space = JCS_RGB;
324 jpeg_set_defaults(&cinfo);
325 jpeg_start_compress(&cinfo, TRUE);
326
327 stride = cinfo.image_width * 3; /* JSAMPLEs per row in image_buffer */
328 image_buffer = image->GetData();
329 while (cinfo.next_scanline < cinfo.image_height) {
330 row_pointer[0] = &image_buffer[cinfo.next_scanline * stride];
331 jpeg_write_scanlines( &cinfo, row_pointer, 1 );
332 }
333 jpeg_finish_compress(&cinfo);
334 jpeg_destroy_compress(&cinfo);
335
336 return TRUE;
337 }
338
339
340 bool wxJPEGHandler::DoCanRead( wxInputStream& stream )
341 {
342 unsigned char hdr[2];
343
344 stream.Read(&hdr, 2);
345 stream.SeekI(-2, wxFromCurrent);
346 return (hdr[0] == 0xFF && hdr[1] == 0xD8);
347 }
348
349 #endif // wxUSE_STREAMS
350
351 #endif // wxUSE_LIBJPEG
352
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