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Thomas G. Lane36a4ccc1994-09-24 00:00:00 +00001/*
2 * rdbmp.c
3 *
Thomas G. Lane489583f1996-02-07 00:00:00 +00004 * Copyright (C) 1994-1996, Thomas G. Lane.
Thomas G. Lane36a4ccc1994-09-24 00:00:00 +00005 * 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
32typedef unsigned char U_CHAR;
33#define UCH(x) ((int) (x))
34#else /* !HAVE_UNSIGNED_CHAR */
35#ifdef CHAR_IS_UNSIGNED
36typedef char U_CHAR;
37#define UCH(x) ((int) (x))
38#else
39typedef 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
50typedef struct _bmp_source_struct * bmp_source_ptr;
51
52typedef 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
Thomas G. Lane489583f1996-02-07 00:00:00 +000067LOCAL(int)
Thomas G. Lane36a4ccc1994-09-24 00:00:00 +000068read_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
Thomas G. Lane489583f1996-02-07 00:00:00 +000080LOCAL(void)
Thomas G. Lane36a4ccc1994-09-24 00:00:00 +000081read_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
Thomas G. Lane489583f1996-02-07 00:00:00 +0000118METHODDEF(JDIMENSION)
Thomas G. Lane36a4ccc1994-09-24 00:00:00 +0000119get_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)
Thomas G. Lanebc79e061995-08-02 00:00:00 +0000132 ((j_common_ptr) cinfo, source->whole_image,
133 source->source_row, (JDIMENSION) 1, FALSE);
Thomas G. Lane36a4ccc1994-09-24 00:00:00 +0000134
135 /* Expand the colormap indexes to real data */
136 inptr = image_ptr[0];
137 outptr = source->pub.buffer[0];
138 for (col = cinfo->image_width; col > 0; col--) {
139 t = GETJSAMPLE(*inptr++);
140 *outptr++ = colormap[0][t]; /* can omit GETJSAMPLE() safely */
141 *outptr++ = colormap[1][t];
142 *outptr++ = colormap[2][t];
143 }
144
145 return 1;
146}
147
148
Thomas G. Lane489583f1996-02-07 00:00:00 +0000149METHODDEF(JDIMENSION)
Thomas G. Lane36a4ccc1994-09-24 00:00:00 +0000150get_24bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
151/* This version is for reading 24-bit pixels */
152{
153 bmp_source_ptr source = (bmp_source_ptr) sinfo;
154 JSAMPARRAY image_ptr;
155 register JSAMPROW inptr, outptr;
156 register JDIMENSION col;
157
158 /* Fetch next row from virtual array */
159 source->source_row--;
160 image_ptr = (*cinfo->mem->access_virt_sarray)
Thomas G. Lanebc79e061995-08-02 00:00:00 +0000161 ((j_common_ptr) cinfo, source->whole_image,
162 source->source_row, (JDIMENSION) 1, FALSE);
Thomas G. Lane36a4ccc1994-09-24 00:00:00 +0000163
164 /* Transfer data. Note source values are in BGR order
165 * (even though Microsoft's own documents say the opposite).
166 */
167 inptr = image_ptr[0];
168 outptr = source->pub.buffer[0];
169 for (col = cinfo->image_width; col > 0; col--) {
170 outptr[2] = *inptr++; /* can omit GETJSAMPLE() safely */
171 outptr[1] = *inptr++;
172 outptr[0] = *inptr++;
173 outptr += 3;
174 }
175
176 return 1;
177}
178
179
180/*
181 * This method loads the image into whole_image during the first call on
182 * get_pixel_rows. The get_pixel_rows pointer is then adjusted to call
183 * get_8bit_row or get_24bit_row on subsequent calls.
184 */
185
Thomas G. Lane489583f1996-02-07 00:00:00 +0000186METHODDEF(JDIMENSION)
Thomas G. Lane36a4ccc1994-09-24 00:00:00 +0000187preload_image (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
188{
189 bmp_source_ptr source = (bmp_source_ptr) sinfo;
190 register FILE *infile = source->pub.input_file;
191 register int c;
192 register JSAMPROW out_ptr;
193 JSAMPARRAY image_ptr;
194 JDIMENSION row, col;
195 cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
196
197 /* Read the data into a virtual array in input-file row order. */
198 for (row = 0; row < cinfo->image_height; row++) {
199 if (progress != NULL) {
200 progress->pub.pass_counter = (long) row;
201 progress->pub.pass_limit = (long) cinfo->image_height;
202 (*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
203 }
204 image_ptr = (*cinfo->mem->access_virt_sarray)
Thomas G. Lanebc79e061995-08-02 00:00:00 +0000205 ((j_common_ptr) cinfo, source->whole_image,
206 row, (JDIMENSION) 1, TRUE);
Thomas G. Lane36a4ccc1994-09-24 00:00:00 +0000207 out_ptr = image_ptr[0];
208 for (col = source->row_width; col > 0; col--) {
209 /* inline copy of read_byte() for speed */
210 if ((c = getc(infile)) == EOF)
211 ERREXIT(cinfo, JERR_INPUT_EOF);
212 *out_ptr++ = (JSAMPLE) c;
213 }
214 }
215 if (progress != NULL)
216 progress->completed_extra_passes++;
217
218 /* Set up to read from the virtual array in top-to-bottom order */
219 switch (source->bits_per_pixel) {
220 case 8:
221 source->pub.get_pixel_rows = get_8bit_row;
222 break;
223 case 24:
224 source->pub.get_pixel_rows = get_24bit_row;
225 break;
226 default:
227 ERREXIT(cinfo, JERR_BMP_BADDEPTH);
228 }
229 source->source_row = cinfo->image_height;
230
231 /* And read the first row */
232 return (*source->pub.get_pixel_rows) (cinfo, sinfo);
233}
234
235
236/*
237 * Read the file header; return image size and component count.
238 */
239
Thomas G. Lane489583f1996-02-07 00:00:00 +0000240METHODDEF(void)
Thomas G. Lane36a4ccc1994-09-24 00:00:00 +0000241start_input_bmp (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
242{
243 bmp_source_ptr source = (bmp_source_ptr) sinfo;
244 U_CHAR bmpfileheader[14];
245 U_CHAR bmpinfoheader[64];
246#define GET_2B(array,offset) ((unsigned int) UCH(array[offset]) + \
247 (((unsigned int) UCH(array[offset+1])) << 8))
248#define GET_4B(array,offset) ((INT32) UCH(array[offset]) + \
249 (((INT32) UCH(array[offset+1])) << 8) + \
250 (((INT32) UCH(array[offset+2])) << 16) + \
251 (((INT32) UCH(array[offset+3])) << 24))
Thomas G. Lane9ba2f5e1994-12-07 00:00:00 +0000252 INT32 bfOffBits;
Thomas G. Lane36a4ccc1994-09-24 00:00:00 +0000253 INT32 headerSize;
254 INT32 biWidth = 0; /* initialize to avoid compiler warning */
255 INT32 biHeight = 0;
256 unsigned int biPlanes;
257 INT32 biCompression;
258 INT32 biXPelsPerMeter,biYPelsPerMeter;
259 INT32 biClrUsed = 0;
260 int mapentrysize = 0; /* 0 indicates no colormap */
Thomas G. Lane9ba2f5e1994-12-07 00:00:00 +0000261 INT32 bPad;
Thomas G. Lane36a4ccc1994-09-24 00:00:00 +0000262 JDIMENSION row_width;
263
264 /* Read and verify the bitmap file header */
265 if (! ReadOK(source->pub.input_file, bmpfileheader, 14))
266 ERREXIT(cinfo, JERR_INPUT_EOF);
267 if (GET_2B(bmpfileheader,0) != 0x4D42) /* 'BM' */
268 ERREXIT(cinfo, JERR_BMP_NOT);
Thomas G. Lane9ba2f5e1994-12-07 00:00:00 +0000269 bfOffBits = (INT32) GET_4B(bmpfileheader,10);
Thomas G. Lane36a4ccc1994-09-24 00:00:00 +0000270 /* We ignore the remaining fileheader fields */
271
272 /* The infoheader might be 12 bytes (OS/2 1.x), 40 bytes (Windows),
273 * or 64 bytes (OS/2 2.x). Check the first 4 bytes to find out which.
274 */
275 if (! ReadOK(source->pub.input_file, bmpinfoheader, 4))
276 ERREXIT(cinfo, JERR_INPUT_EOF);
277 headerSize = (INT32) GET_4B(bmpinfoheader,0);
278 if (headerSize < 12 || headerSize > 64)
279 ERREXIT(cinfo, JERR_BMP_BADHEADER);
280 if (! ReadOK(source->pub.input_file, bmpinfoheader+4, headerSize-4))
281 ERREXIT(cinfo, JERR_INPUT_EOF);
282
283 switch ((int) headerSize) {
284 case 12:
285 /* Decode OS/2 1.x header (Microsoft calls this a BITMAPCOREHEADER) */
286 biWidth = (INT32) GET_2B(bmpinfoheader,4);
287 biHeight = (INT32) GET_2B(bmpinfoheader,6);
288 biPlanes = GET_2B(bmpinfoheader,8);
289 source->bits_per_pixel = (int) GET_2B(bmpinfoheader,10);
290
291 switch (source->bits_per_pixel) {
292 case 8: /* colormapped image */
293 mapentrysize = 3; /* OS/2 uses RGBTRIPLE colormap */
294 TRACEMS2(cinfo, 1, JTRC_BMP_OS2_MAPPED, (int) biWidth, (int) biHeight);
295 break;
296 case 24: /* RGB image */
297 TRACEMS2(cinfo, 1, JTRC_BMP_OS2, (int) biWidth, (int) biHeight);
298 break;
299 default:
300 ERREXIT(cinfo, JERR_BMP_BADDEPTH);
301 break;
302 }
303 if (biPlanes != 1)
304 ERREXIT(cinfo, JERR_BMP_BADPLANES);
305 break;
306 case 40:
307 case 64:
308 /* Decode Windows 3.x header (Microsoft calls this a BITMAPINFOHEADER) */
309 /* or OS/2 2.x header, which has additional fields that we ignore */
310 biWidth = GET_4B(bmpinfoheader,4);
311 biHeight = GET_4B(bmpinfoheader,8);
312 biPlanes = GET_2B(bmpinfoheader,12);
313 source->bits_per_pixel = (int) GET_2B(bmpinfoheader,14);
314 biCompression = GET_4B(bmpinfoheader,16);
315 biXPelsPerMeter = GET_4B(bmpinfoheader,24);
316 biYPelsPerMeter = GET_4B(bmpinfoheader,28);
317 biClrUsed = GET_4B(bmpinfoheader,32);
318 /* biSizeImage, biClrImportant fields are ignored */
319
320 switch (source->bits_per_pixel) {
321 case 8: /* colormapped image */
322 mapentrysize = 4; /* Windows uses RGBQUAD colormap */
323 TRACEMS2(cinfo, 1, JTRC_BMP_MAPPED, (int) biWidth, (int) biHeight);
324 break;
325 case 24: /* RGB image */
326 TRACEMS2(cinfo, 1, JTRC_BMP, (int) biWidth, (int) biHeight);
327 break;
328 default:
329 ERREXIT(cinfo, JERR_BMP_BADDEPTH);
330 break;
331 }
332 if (biPlanes != 1)
333 ERREXIT(cinfo, JERR_BMP_BADPLANES);
334 if (biCompression != 0)
335 ERREXIT(cinfo, JERR_BMP_COMPRESSED);
336
337 if (biXPelsPerMeter > 0 && biYPelsPerMeter > 0) {
338 /* Set JFIF density parameters from the BMP data */
339 cinfo->X_density = (UINT16) (biXPelsPerMeter/100); /* 100 cm per meter */
340 cinfo->Y_density = (UINT16) (biYPelsPerMeter/100);
341 cinfo->density_unit = 2; /* dots/cm */
342 }
343 break;
344 default:
345 ERREXIT(cinfo, JERR_BMP_BADHEADER);
346 break;
347 }
348
Thomas G. Lane9ba2f5e1994-12-07 00:00:00 +0000349 /* Compute distance to bitmap data --- will adjust for colormap below */
350 bPad = bfOffBits - (headerSize + 14);
351
Thomas G. Lane36a4ccc1994-09-24 00:00:00 +0000352 /* Read the colormap, if any */
353 if (mapentrysize > 0) {
354 if (biClrUsed <= 0)
355 biClrUsed = 256; /* assume it's 256 */
356 else if (biClrUsed > 256)
357 ERREXIT(cinfo, JERR_BMP_BADCMAP);
358 /* Allocate space to store the colormap */
359 source->colormap = (*cinfo->mem->alloc_sarray)
360 ((j_common_ptr) cinfo, JPOOL_IMAGE,
361 (JDIMENSION) biClrUsed, (JDIMENSION) 3);
362 /* and read it from the file */
363 read_colormap(source, (int) biClrUsed, mapentrysize);
Thomas G. Lane9ba2f5e1994-12-07 00:00:00 +0000364 /* account for size of colormap */
365 bPad -= biClrUsed * mapentrysize;
366 }
367
368 /* Skip any remaining pad bytes */
369 if (bPad < 0) /* incorrect bfOffBits value? */
370 ERREXIT(cinfo, JERR_BMP_BADHEADER);
371 while (--bPad >= 0) {
372 (void) read_byte(source);
Thomas G. Lane36a4ccc1994-09-24 00:00:00 +0000373 }
374
375 /* Compute row width in file, including padding to 4-byte boundary */
376 if (source->bits_per_pixel == 24)
377 row_width = (JDIMENSION) (biWidth * 3);
378 else
379 row_width = (JDIMENSION) biWidth;
380 while ((row_width & 3) != 0) row_width++;
381 source->row_width = row_width;
382
383 /* Allocate space for inversion array, prepare for preload pass */
384 source->whole_image = (*cinfo->mem->request_virt_sarray)
Thomas G. Lanebc79e061995-08-02 00:00:00 +0000385 ((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
Thomas G. Lane36a4ccc1994-09-24 00:00:00 +0000386 row_width, (JDIMENSION) biHeight, (JDIMENSION) 1);
387 source->pub.get_pixel_rows = preload_image;
388 if (cinfo->progress != NULL) {
389 cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
390 progress->total_extra_passes++; /* count file input as separate pass */
391 }
392
393 /* Allocate one-row buffer for returned data */
394 source->pub.buffer = (*cinfo->mem->alloc_sarray)
395 ((j_common_ptr) cinfo, JPOOL_IMAGE,
396 (JDIMENSION) (biWidth * 3), (JDIMENSION) 1);
397 source->pub.buffer_height = 1;
398
399 cinfo->in_color_space = JCS_RGB;
400 cinfo->input_components = 3;
401 cinfo->data_precision = 8;
402 cinfo->image_width = (JDIMENSION) biWidth;
403 cinfo->image_height = (JDIMENSION) biHeight;
404}
405
406
407/*
408 * Finish up at the end of the file.
409 */
410
Thomas G. Lane489583f1996-02-07 00:00:00 +0000411METHODDEF(void)
Thomas G. Lane36a4ccc1994-09-24 00:00:00 +0000412finish_input_bmp (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
413{
414 /* no work */
415}
416
417
418/*
419 * The module selection routine for BMP format input.
420 */
421
Thomas G. Lane489583f1996-02-07 00:00:00 +0000422GLOBAL(cjpeg_source_ptr)
Thomas G. Lane36a4ccc1994-09-24 00:00:00 +0000423jinit_read_bmp (j_compress_ptr cinfo)
424{
425 bmp_source_ptr source;
426
427 /* Create module interface object */
428 source = (bmp_source_ptr)
429 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
430 SIZEOF(bmp_source_struct));
431 source->cinfo = cinfo; /* make back link for subroutines */
432 /* Fill in method ptrs, except get_pixel_rows which start_input sets */
433 source->pub.start_input = start_input_bmp;
434 source->pub.finish_input = finish_input_bmp;
435
436 return (cjpeg_source_ptr) source;
437}
438
439#endif /* BMP_SUPPORTED */