1 /*
2 * rdbmp.c
3 *
4 * Copyright (C) 1994, Thomas G. Lane.
5 * This file is part of the Independent JPEG Group's software.
6 * For conditions of distribution and use, see the accompanying README file.
7 *
8 * This file contains routines to read input images in Microsoft "BMP"
9 * format (MS Windows 3.x, OS/2 1.x, and OS/2 2.x flavors).
10 * Currently, only 8-bit and 24-bit images are supported, not 1-bit or
11 * 4-bit (feeding such low-depth images into JPEG would be silly anyway).
12 * Also, we don't support RLE-compressed files.
13 *
14 * These routines may need modification for non-Unix environments or
15 * specialized applications. As they stand, they assume input from
16 * an ordinary stdio stream. They further assume that reading begins
17 * at the start of the file; start_input may need work if the
18 * user interface has already read some data (e.g., to determine that
19 * the file is indeed BMP format).
20 *
21 * This code contributed by James Arthur Boucher.
22 */
23
24 #include "cdjpeg.h" /* Common decls for cjpeg/djpeg applications */
25
26 #ifdef BMP_SUPPORTED
27
28
29 /* Macros to deal with unsigned chars as efficiently as compiler allows */
30
31 #ifdef HAVE_UNSIGNED_CHAR
32 typedef unsigned char U_CHAR;
33 #define UCH(x) ((int) (x))
34 #else /* !HAVE_UNSIGNED_CHAR */
35 #ifdef CHAR_IS_UNSIGNED
36 typedef char U_CHAR;
37 #define UCH(x) ((int) (x))
38 #else
39 typedef char U_CHAR;
40 #define UCH(x) ((int) (x) & 0xFF)
41 #endif
42 #endif /* HAVE_UNSIGNED_CHAR */
43
44
45 #define ReadOK(file,buffer,len) (JFREAD(file,buffer,len) == ((size_t) (len)))
46
47
48 /* Private version of data source object */
49
50 typedef struct _bmp_source_struct * bmp_source_ptr;
51
52 typedef struct _bmp_source_struct {
53 struct cjpeg_source_struct pub; /* public fields */
54
55 j_compress_ptr cinfo; /* back link saves passing separate parm */
56
57 JSAMPARRAY colormap; /* BMP colormap (converted to my format) */
58
59 jvirt_sarray_ptr whole_image; /* Needed to reverse row order */
60 JDIMENSION source_row; /* Current source row number */
61 JDIMENSION row_width; /* Physical width of scanlines in file */
62
63 int bits_per_pixel; /* remembers 8- or 24-bit format */
64 } bmp_source_struct;
65
66
67 LOCAL int
read_byte(bmp_source_ptr sinfo)68 read_byte (bmp_source_ptr sinfo)
69 /* Read next byte from BMP file */
70 {
71 register FILE *infile = sinfo->pub.input_file;
72 register int c;
73
74 if ((c = getc(infile)) == EOF)
75 ERREXIT(sinfo->cinfo, JERR_INPUT_EOF);
76 return c;
77 }
78
79
80 LOCAL void
read_colormap(bmp_source_ptr sinfo,int cmaplen,int mapentrysize)81 read_colormap (bmp_source_ptr sinfo, int cmaplen, int mapentrysize)
82 /* Read the colormap from a BMP file */
83 {
84 int i;
85
86 switch (mapentrysize) {
87 case 3:
88 /* BGR format (occurs in OS/2 files) */
89 for (i = 0; i < cmaplen; i++) {
90 sinfo->colormap[2][i] = (JSAMPLE) read_byte(sinfo);
91 sinfo->colormap[1][i] = (JSAMPLE) read_byte(sinfo);
92 sinfo->colormap[0][i] = (JSAMPLE) read_byte(sinfo);
93 }
94 break;
95 case 4:
96 /* BGR0 format (occurs in MS Windows files) */
97 for (i = 0; i < cmaplen; i++) {
98 sinfo->colormap[2][i] = (JSAMPLE) read_byte(sinfo);
99 sinfo->colormap[1][i] = (JSAMPLE) read_byte(sinfo);
100 sinfo->colormap[0][i] = (JSAMPLE) read_byte(sinfo);
101 (void) read_byte(sinfo);
102 }
103 break;
104 default:
105 ERREXIT(sinfo->cinfo, JERR_BMP_BADCMAP);
106 break;
107 }
108 }
109
110
111 /*
112 * Read one row of pixels.
113 * The image has been read into the whole_image array, but is otherwise
114 * unprocessed. We must read it out in top-to-bottom row order, and if
115 * it is an 8-bit image, we must expand colormapped pixels to 24bit format.
116 */
117
118 METHODDEF JDIMENSION
get_8bit_row(j_compress_ptr cinfo,cjpeg_source_ptr sinfo)119 get_8bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
120 /* This version is for reading 8-bit colormap indexes */
121 {
122 bmp_source_ptr source = (bmp_source_ptr) sinfo;
123 register JSAMPARRAY colormap = source->colormap;
124 JSAMPARRAY image_ptr;
125 register int t;
126 register JSAMPROW inptr, outptr;
127 register JDIMENSION col;
128
129 /* Fetch next row from virtual array */
130 source->source_row--;
131 image_ptr = (*cinfo->mem->access_virt_sarray)
132 ((j_common_ptr) cinfo, source->whole_image, source->source_row, FALSE);
133
134 /* Expand the colormap indexes to real data */
135 inptr = image_ptr[0];
136 outptr = source->pub.buffer[0];
137 for (col = cinfo->image_width; col > 0; col--) {
138 t = GETJSAMPLE(*inptr++);
139 *outptr++ = colormap[0][t]; /* can omit GETJSAMPLE() safely */
140 *outptr++ = colormap[1][t];
141 *outptr++ = colormap[2][t];
142 }
143
144 return 1;
145 }
146
147
148 METHODDEF JDIMENSION
get_24bit_row(j_compress_ptr cinfo,cjpeg_source_ptr sinfo)149 get_24bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
150 /* This version is for reading 24-bit pixels */
151 {
152 bmp_source_ptr source = (bmp_source_ptr) sinfo;
153 JSAMPARRAY image_ptr;
154 register JSAMPROW inptr, outptr;
155 register JDIMENSION col;
156
157 /* Fetch next row from virtual array */
158 source->source_row--;
159 image_ptr = (*cinfo->mem->access_virt_sarray)
160 ((j_common_ptr) cinfo, source->whole_image, source->source_row, FALSE);
161
162 /* Transfer data. Note source values are in BGR order
163 * (even though Microsoft's own documents say the opposite).
164 */
165 inptr = image_ptr[0];
166 outptr = source->pub.buffer[0];
167 for (col = cinfo->image_width; col > 0; col--) {
168 outptr[2] = *inptr++; /* can omit GETJSAMPLE() safely */
169 outptr[1] = *inptr++;
170 outptr[0] = *inptr++;
171 outptr += 3;
172 }
173
174 return 1;
175 }
176
177
178 /*
179 * This method loads the image into whole_image during the first call on
180 * get_pixel_rows. The get_pixel_rows pointer is then adjusted to call
181 * get_8bit_row or get_24bit_row on subsequent calls.
182 */
183
184 METHODDEF JDIMENSION
preload_image(j_compress_ptr cinfo,cjpeg_source_ptr sinfo)185 preload_image (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
186 {
187 bmp_source_ptr source = (bmp_source_ptr) sinfo;
188 register FILE *infile = source->pub.input_file;
189 register int c;
190 register JSAMPROW out_ptr;
191 JSAMPARRAY image_ptr;
192 JDIMENSION row, col;
193 cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
194
195 /* Read the data into a virtual array in input-file row order. */
196 for (row = 0; row < cinfo->image_height; row++) {
197 if (progress != NULL) {
198 progress->pub.pass_counter = (long) row;
199 progress->pub.pass_limit = (long) cinfo->image_height;
200 (*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
201 }
202 image_ptr = (*cinfo->mem->access_virt_sarray)
203 ((j_common_ptr) cinfo, source->whole_image, row, TRUE);
204 out_ptr = image_ptr[0];
205 for (col = source->row_width; col > 0; col--) {
206 /* inline copy of read_byte() for speed */
207 if ((c = getc(infile)) == EOF)
208 ERREXIT(cinfo, JERR_INPUT_EOF);
209 *out_ptr++ = (JSAMPLE) c;
210 }
211 }
212 if (progress != NULL)
213 progress->completed_extra_passes++;
214
215 /* Set up to read from the virtual array in top-to-bottom order */
216 switch (source->bits_per_pixel) {
217 case 8:
218 source->pub.get_pixel_rows = get_8bit_row;
219 break;
220 case 24:
221 source->pub.get_pixel_rows = get_24bit_row;
222 break;
223 default:
224 ERREXIT(cinfo, JERR_BMP_BADDEPTH);
225 }
226 source->source_row = cinfo->image_height;
227
228 /* And read the first row */
229 return (*source->pub.get_pixel_rows) (cinfo, sinfo);
230 }
231
232
233 /*
234 * Read the file header; return image size and component count.
235 */
236
237 METHODDEF void
start_input_bmp(j_compress_ptr cinfo,cjpeg_source_ptr sinfo)238 start_input_bmp (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
239 {
240 bmp_source_ptr source = (bmp_source_ptr) sinfo;
241 U_CHAR bmpfileheader[14];
242 U_CHAR bmpinfoheader[64];
243 #define GET_2B(array,offset) ((unsigned int) UCH(array[offset]) + \
244 (((unsigned int) UCH(array[offset+1])) << 8))
245 #define GET_4B(array,offset) ((INT32) UCH(array[offset]) + \
246 (((INT32) UCH(array[offset+1])) << 8) + \
247 (((INT32) UCH(array[offset+2])) << 16) + \
248 (((INT32) UCH(array[offset+3])) << 24))
249 INT32 bfOffBits;
250 INT32 headerSize;
251 INT32 biWidth = 0; /* initialize to avoid compiler warning */
252 INT32 biHeight = 0;
253 unsigned int biPlanes;
254 INT32 biCompression;
255 INT32 biXPelsPerMeter,biYPelsPerMeter;
256 INT32 biClrUsed = 0;
257 int mapentrysize = 0; /* 0 indicates no colormap */
258 INT32 bPad;
259 JDIMENSION row_width;
260
261 /* Read and verify the bitmap file header */
262 if (! ReadOK(source->pub.input_file, bmpfileheader, 14))
263 ERREXIT(cinfo, JERR_INPUT_EOF);
264 if (GET_2B(bmpfileheader,0) != 0x4D42) /* 'BM' */
265 ERREXIT(cinfo, JERR_BMP_NOT);
266 bfOffBits = (INT32) GET_4B(bmpfileheader,10);
267 /* We ignore the remaining fileheader fields */
268
269 /* The infoheader might be 12 bytes (OS/2 1.x), 40 bytes (Windows),
270 * or 64 bytes (OS/2 2.x). Check the first 4 bytes to find out which.
271 */
272 if (! ReadOK(source->pub.input_file, bmpinfoheader, 4))
273 ERREXIT(cinfo, JERR_INPUT_EOF);
274 headerSize = (INT32) GET_4B(bmpinfoheader,0);
275 if (headerSize < 12 || headerSize > 64)
276 ERREXIT(cinfo, JERR_BMP_BADHEADER);
277 if (! ReadOK(source->pub.input_file, bmpinfoheader+4, headerSize-4))
278 ERREXIT(cinfo, JERR_INPUT_EOF);
279
280 switch ((int) headerSize) {
281 case 12:
282 /* Decode OS/2 1.x header (Microsoft calls this a BITMAPCOREHEADER) */
283 biWidth = (INT32) GET_2B(bmpinfoheader,4);
284 biHeight = (INT32) GET_2B(bmpinfoheader,6);
285 biPlanes = GET_2B(bmpinfoheader,8);
286 source->bits_per_pixel = (int) GET_2B(bmpinfoheader,10);
287
288 switch (source->bits_per_pixel) {
289 case 8: /* colormapped image */
290 mapentrysize = 3; /* OS/2 uses RGBTRIPLE colormap */
291 TRACEMS2(cinfo, 1, JTRC_BMP_OS2_MAPPED, (int) biWidth, (int) biHeight);
292 break;
293 case 24: /* RGB image */
294 TRACEMS2(cinfo, 1, JTRC_BMP_OS2, (int) biWidth, (int) biHeight);
295 break;
296 default:
297 ERREXIT(cinfo, JERR_BMP_BADDEPTH);
298 break;
299 }
300 if (biPlanes != 1)
301 ERREXIT(cinfo, JERR_BMP_BADPLANES);
302 break;
303 case 40:
304 case 64:
305 /* Decode Windows 3.x header (Microsoft calls this a BITMAPINFOHEADER) */
306 /* or OS/2 2.x header, which has additional fields that we ignore */
307 biWidth = GET_4B(bmpinfoheader,4);
308 biHeight = GET_4B(bmpinfoheader,8);
309 biPlanes = GET_2B(bmpinfoheader,12);
310 source->bits_per_pixel = (int) GET_2B(bmpinfoheader,14);
311 biCompression = GET_4B(bmpinfoheader,16);
312 biXPelsPerMeter = GET_4B(bmpinfoheader,24);
313 biYPelsPerMeter = GET_4B(bmpinfoheader,28);
314 biClrUsed = GET_4B(bmpinfoheader,32);
315 /* biSizeImage, biClrImportant fields are ignored */
316
317 switch (source->bits_per_pixel) {
318 case 8: /* colormapped image */
319 mapentrysize = 4; /* Windows uses RGBQUAD colormap */
320 TRACEMS2(cinfo, 1, JTRC_BMP_MAPPED, (int) biWidth, (int) biHeight);
321 break;
322 case 24: /* RGB image */
323 TRACEMS2(cinfo, 1, JTRC_BMP, (int) biWidth, (int) biHeight);
324 break;
325 default:
326 ERREXIT(cinfo, JERR_BMP_BADDEPTH);
327 break;
328 }
329 if (biPlanes != 1)
330 ERREXIT(cinfo, JERR_BMP_BADPLANES);
331 if (biCompression != 0)
332 ERREXIT(cinfo, JERR_BMP_COMPRESSED);
333
334 if (biXPelsPerMeter > 0 && biYPelsPerMeter > 0) {
335 /* Set JFIF density parameters from the BMP data */
336 cinfo->X_density = (UINT16) (biXPelsPerMeter/100); /* 100 cm per meter */
337 cinfo->Y_density = (UINT16) (biYPelsPerMeter/100);
338 cinfo->density_unit = 2; /* dots/cm */
339 }
340 break;
341 default:
342 ERREXIT(cinfo, JERR_BMP_BADHEADER);
343 break;
344 }
345
346 /* Compute distance to bitmap data --- will adjust for colormap below */
347 bPad = bfOffBits - (headerSize + 14);
348
349 /* Read the colormap, if any */
350 if (mapentrysize > 0) {
351 if (biClrUsed <= 0)
352 biClrUsed = 256; /* assume it's 256 */
353 else if (biClrUsed > 256)
354 ERREXIT(cinfo, JERR_BMP_BADCMAP);
355 /* Allocate space to store the colormap */
356 source->colormap = (*cinfo->mem->alloc_sarray)
357 ((j_common_ptr) cinfo, JPOOL_IMAGE,
358 (JDIMENSION) biClrUsed, (JDIMENSION) 3);
359 /* and read it from the file */
360 read_colormap(source, (int) biClrUsed, mapentrysize);
361 /* account for size of colormap */
362 bPad -= biClrUsed * mapentrysize;
363 }
364
365 /* Skip any remaining pad bytes */
366 if (bPad < 0) /* incorrect bfOffBits value? */
367 ERREXIT(cinfo, JERR_BMP_BADHEADER);
368 while (--bPad >= 0) {
369 (void) read_byte(source);
370 }
371
372 /* Compute row width in file, including padding to 4-byte boundary */
373 if (source->bits_per_pixel == 24)
374 row_width = (JDIMENSION) (biWidth * 3);
375 else
376 row_width = (JDIMENSION) biWidth;
377 while ((row_width & 3) != 0) row_width++;
378 source->row_width = row_width;
379
380 /* Allocate space for inversion array, prepare for preload pass */
381 source->whole_image = (*cinfo->mem->request_virt_sarray)
382 ((j_common_ptr) cinfo, JPOOL_IMAGE,
383 row_width, (JDIMENSION) biHeight, (JDIMENSION) 1);
384 source->pub.get_pixel_rows = preload_image;
385 if (cinfo->progress != NULL) {
386 cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
387 progress->total_extra_passes++; /* count file input as separate pass */
388 }
389
390 /* Allocate one-row buffer for returned data */
391 source->pub.buffer = (*cinfo->mem->alloc_sarray)
392 ((j_common_ptr) cinfo, JPOOL_IMAGE,
393 (JDIMENSION) (biWidth * 3), (JDIMENSION) 1);
394 source->pub.buffer_height = 1;
395
396 cinfo->in_color_space = JCS_RGB;
397 cinfo->input_components = 3;
398 cinfo->data_precision = 8;
399 cinfo->image_width = (JDIMENSION) biWidth;
400 cinfo->image_height = (JDIMENSION) biHeight;
401 }
402
403
404 /*
405 * Finish up at the end of the file.
406 */
407
408 METHODDEF void
finish_input_bmp(j_compress_ptr cinfo,cjpeg_source_ptr sinfo)409 finish_input_bmp (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
410 {
411 /* no work */
412 }
413
414
415 /*
416 * The module selection routine for BMP format input.
417 */
418
419 GLOBAL cjpeg_source_ptr
jinit_read_bmp(j_compress_ptr cinfo)420 jinit_read_bmp (j_compress_ptr cinfo)
421 {
422 bmp_source_ptr source;
423
424 /* Create module interface object */
425 source = (bmp_source_ptr)
426 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
427 SIZEOF(bmp_source_struct));
428 source->cinfo = cinfo; /* make back link for subroutines */
429 /* Fill in method ptrs, except get_pixel_rows which start_input sets */
430 source->pub.start_input = start_input_bmp;
431 source->pub.finish_input = finish_input_bmp;
432
433 return (cjpeg_source_ptr) source;
434 }
435
436 #endif /* BMP_SUPPORTED */
437