1 /////////////////////////////////////////////////////////////////////////////
3 // Purpose: wxImage JPEG handler
4 // Author: Vaclav Slavik
6 // Copyright: (c) Vaclav Slavik
7 // Licence: wxWindows licence
8 /////////////////////////////////////////////////////////////////////////////
11 #pragma implementation "imagjpeg.h"
14 // For compilers that support precompilation, includes "wx.h".
15 #include "wx/wxprec.h"
23 #if wxUSE_IMAGE && wxUSE_LIBJPEG
25 #include "wx/imagjpeg.h"
26 #include "wx/bitmap.h"
34 #include "wx/filefn.h"
35 #include "wx/wfstream.h"
37 #include "wx/module.h"
41 // For JPEG library error handling
54 //-----------------------------------------------------------------------------
56 //-----------------------------------------------------------------------------
58 IMPLEMENT_DYNAMIC_CLASS(wxJPEGHandler
,wxImageHandler
)
62 //------------- JPEG Data Source Manager
64 #define JPEG_IO_BUFFER_SIZE 2048
67 struct jpeg_source_mgr pub
; /* public fields */
69 JOCTET
* buffer
; /* start of buffer */
70 wxInputStream
*stream
;
73 typedef my_source_mgr
* my_src_ptr
;
75 METHODDEF(void) my_init_source ( j_decompress_ptr
WXUNUSED(cinfo
) )
79 METHODDEF(boolean
) my_fill_input_buffer ( j_decompress_ptr cinfo
)
81 my_src_ptr src
= (my_src_ptr
) cinfo
->src
;
83 src
->pub
.next_input_byte
= src
->buffer
;
84 src
->pub
.bytes_in_buffer
= src
->stream
->Read(src
->buffer
, JPEG_IO_BUFFER_SIZE
).LastRead();
86 if (src
->pub
.bytes_in_buffer
== 0) // check for end-of-stream
88 // Insert a fake EOI marker
89 src
->buffer
[0] = 0xFF;
90 src
->buffer
[1] = JPEG_EOI
;
91 src
->pub
.bytes_in_buffer
= 2;
96 METHODDEF(void) my_skip_input_data ( j_decompress_ptr cinfo
, long num_bytes
)
100 my_src_ptr src
= (my_src_ptr
) cinfo
->src
;
102 while (num_bytes
> (long)src
->pub
.bytes_in_buffer
)
104 num_bytes
-= (long) src
->pub
.bytes_in_buffer
;
105 src
->pub
.fill_input_buffer(cinfo
);
107 src
->pub
.next_input_byte
+= (size_t) num_bytes
;
108 src
->pub
.bytes_in_buffer
-= (size_t) num_bytes
;
112 METHODDEF(void) my_term_source ( j_decompress_ptr cinfo
)
114 my_src_ptr src
= (my_src_ptr
) cinfo
->src
;
116 if (src
->pub
.bytes_in_buffer
> 0)
117 src
->stream
->SeekI(-(long)src
->pub
.bytes_in_buffer
, wxFromCurrent
);
118 delete[] src
->buffer
;
121 void jpeg_wxio_src( j_decompress_ptr cinfo
, wxInputStream
& infile
)
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
;
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
;
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
;
145 // JPEG error manager:
147 struct my_error_mgr
{
148 struct jpeg_error_mgr pub
; /* "public" fields */
150 jmp_buf setjmp_buffer
; /* for return to caller */
153 typedef struct my_error_mgr
* my_error_ptr
;
156 * Here's the routine that will replace the standard error_exit method:
160 my_error_exit (j_common_ptr cinfo
)
162 /* cinfo->err really points to a my_error_mgr struct, so coerce pointer */
163 my_error_ptr myerr
= (my_error_ptr
) cinfo
->err
;
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
);
169 /* Return control to the setjmp point */
170 longjmp(myerr
->setjmp_buffer
, 1);
173 // temporarily disable the warning C4611 (interaction between '_setjmp' and
174 // C++ object destruction is non-portable) - I don't see any dtors here
176 #pragma warning(disable:4611)
179 bool wxJPEGHandler::LoadFile( wxImage
*image
, wxInputStream
& stream
, bool verbose
, int WXUNUSED(index
) )
181 struct jpeg_decompress_struct cinfo
;
182 struct my_error_mgr jerr
;
188 cinfo
.err
= jpeg_std_error( &jerr
.pub
);
189 jerr
.pub
.error_exit
= my_error_exit
;
191 if (!verbose
) cinfo
.err
->output_message
=NULL
;
193 /* Establish the setjmp return context for my_error_exit to use. */
194 if (setjmp(jerr
.setjmp_buffer
)) {
195 /* If we get here, the JPEG code has signaled an error.
196 * We need to clean up the JPEG object, close the input file, and return.
199 wxLogError(_("JPEG: Couldn't load - file is probably corrupted."));
200 (cinfo
.src
->term_source
)(&cinfo
);
201 jpeg_destroy_decompress(&cinfo
);
202 if (image
->Ok()) image
->Destroy();
206 jpeg_create_decompress( &cinfo
);
207 jpeg_wxio_src( &cinfo
, stream
);
208 jpeg_read_header( &cinfo
, TRUE
);
209 cinfo
.out_color_space
= JCS_RGB
;
210 jpeg_start_decompress( &cinfo
);
212 image
->Create( cinfo
.image_width
, cinfo
.image_height
);
214 jpeg_finish_decompress( &cinfo
);
215 jpeg_destroy_decompress( &cinfo
);
218 image
->SetMask( FALSE
);
219 ptr
= image
->GetData();
220 stride
= cinfo
.output_width
* 3;
221 tempbuf
= (*cinfo
.mem
->alloc_sarray
)
222 ((j_common_ptr
) &cinfo
, JPOOL_IMAGE
, stride
, 1 );
224 while ( cinfo
.output_scanline
< cinfo
.output_height
) {
225 jpeg_read_scanlines( &cinfo
, tempbuf
, 1 );
226 memcpy( ptr
, tempbuf
[0], stride
);
229 jpeg_finish_decompress( &cinfo
);
230 jpeg_destroy_decompress( &cinfo
);
235 struct jpeg_destination_mgr pub
;
237 wxOutputStream
*stream
;
239 } my_destination_mgr
;
241 typedef my_destination_mgr
* my_dest_ptr
;
243 #define OUTPUT_BUF_SIZE 4096 /* choose an efficiently fwrite'able size */
245 METHODDEF(void) init_destination (j_compress_ptr cinfo
)
247 my_dest_ptr dest
= (my_dest_ptr
) cinfo
->dest
;
249 /* Allocate the output buffer --- it will be released when done with image */
250 dest
->buffer
= (JOCTET
*)
251 (*cinfo
->mem
->alloc_small
) ((j_common_ptr
) cinfo
, JPOOL_IMAGE
,
252 OUTPUT_BUF_SIZE
* sizeof(JOCTET
));
253 dest
->pub
.next_output_byte
= dest
->buffer
;
254 dest
->pub
.free_in_buffer
= OUTPUT_BUF_SIZE
;
257 METHODDEF(boolean
) empty_output_buffer (j_compress_ptr cinfo
)
259 my_dest_ptr dest
= (my_dest_ptr
) cinfo
->dest
;
261 dest
->stream
->Write(dest
->buffer
, OUTPUT_BUF_SIZE
);
262 dest
->pub
.next_output_byte
= dest
->buffer
;
263 dest
->pub
.free_in_buffer
= OUTPUT_BUF_SIZE
;
267 METHODDEF(void) term_destination (j_compress_ptr cinfo
)
269 my_dest_ptr dest
= (my_dest_ptr
) cinfo
->dest
;
270 size_t datacount
= OUTPUT_BUF_SIZE
- dest
->pub
.free_in_buffer
;
271 /* Write any data remaining in the buffer */
273 dest
->stream
->Write(dest
->buffer
, datacount
);
276 GLOBAL(void) jpeg_wxio_dest (j_compress_ptr cinfo
, wxOutputStream
& outfile
)
280 if (cinfo
->dest
== NULL
) { /* first time for this JPEG object? */
281 cinfo
->dest
= (struct jpeg_destination_mgr
*)
282 (*cinfo
->mem
->alloc_small
) ((j_common_ptr
) cinfo
, JPOOL_PERMANENT
,
283 sizeof(my_destination_mgr
));
286 dest
= (my_dest_ptr
) cinfo
->dest
;
287 dest
->pub
.init_destination
= init_destination
;
288 dest
->pub
.empty_output_buffer
= empty_output_buffer
;
289 dest
->pub
.term_destination
= term_destination
;
290 dest
->stream
= &outfile
;
293 bool wxJPEGHandler::SaveFile( wxImage
*image
, wxOutputStream
& stream
, bool verbose
)
295 struct jpeg_compress_struct cinfo
;
296 struct my_error_mgr jerr
;
297 JSAMPROW row_pointer
[1]; /* pointer to JSAMPLE row[s] */
298 JSAMPLE
*image_buffer
;
299 int stride
; /* physical row width in image buffer */
301 cinfo
.err
= jpeg_std_error(&jerr
.pub
);
302 jerr
.pub
.error_exit
= my_error_exit
;
304 if (!verbose
) cinfo
.err
->output_message
=NULL
;
306 /* Establish the setjmp return context for my_error_exit to use. */
307 if (setjmp(jerr
.setjmp_buffer
))
309 /* If we get here, the JPEG code has signaled an error.
310 * We need to clean up the JPEG object, close the input file, and return.
313 wxLogError(_("JPEG: Couldn't save image."));
314 jpeg_destroy_compress(&cinfo
);
318 jpeg_create_compress(&cinfo
);
319 jpeg_wxio_dest(&cinfo
, stream
);
321 cinfo
.image_width
= image
->GetWidth();
322 cinfo
.image_height
= image
->GetHeight();
323 cinfo
.input_components
= 3;
324 cinfo
.in_color_space
= JCS_RGB
;
325 jpeg_set_defaults(&cinfo
);
327 // TODO: 3rd parameter is force_baseline, what value should this be?
328 // Code says: "If force_baseline is TRUE, the computed quantization table entries
329 // are limited to 1..255 for JPEG baseline compatibility."
330 // 'Quality' is a number between 0 (terrible) and 100 (very good).
331 // The default (in jcparam.c, jpeg_set_defaults) is 75,
332 // and force_baseline is TRUE.
333 if (image
->HasOption(wxT("quality")))
334 jpeg_set_quality(&cinfo
, image
->GetOptionInt(wxT("quality")), TRUE
);
336 jpeg_start_compress(&cinfo
, TRUE
);
338 stride
= cinfo
.image_width
* 3; /* JSAMPLEs per row in image_buffer */
339 image_buffer
= image
->GetData();
340 while (cinfo
.next_scanline
< cinfo
.image_height
) {
341 row_pointer
[0] = &image_buffer
[cinfo
.next_scanline
* stride
];
342 jpeg_write_scanlines( &cinfo
, row_pointer
, 1 );
344 jpeg_finish_compress(&cinfo
);
345 jpeg_destroy_compress(&cinfo
);
351 #pragma warning(default:4611)
354 bool wxJPEGHandler::DoCanRead( wxInputStream
& stream
)
356 unsigned char hdr
[2];
359 stream
.SeekI(-2, wxFromCurrent
);
360 return (hdr
[0] == 0xFF && hdr
[1] == 0xD8);
363 #endif // wxUSE_STREAMS
365 #endif // wxUSE_LIBJPEG