4
* Copyright (C) 1994-1996, Thomas G. Lane.
5
* Modified 2009-2010 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.
9
* This file contains routines to read input images in Microsoft "BMP"
10
* format (MS Windows 3.x, OS/2 1.x, and OS/2 2.x flavors).
11
* Currently, only 8-bit and 24-bit images are supported, not 1-bit or
12
* 4-bit (feeding such low-depth images into JPEG would be silly anyway).
13
* Also, we don't support RLE-compressed files.
15
* These routines may need modification for non-Unix environments or
16
* specialized applications. As they stand, they assume input from
17
* an ordinary stdio stream. They further assume that reading begins
18
* at the start of the file; start_input may need work if the
19
* user interface has already read some data (e.g., to determine that
20
* the file is indeed BMP format).
22
* This code contributed by James Arthur Boucher.
25
#include "cdjpeg.h" /* Common decls for cjpeg/djpeg applications */
30
/* Macros to deal with unsigned chars as efficiently as compiler allows */
32
#ifdef HAVE_UNSIGNED_CHAR
33
typedef unsigned char U_CHAR;
34
#define UCH(x) ((int) (x))
35
#else /* !HAVE_UNSIGNED_CHAR */
36
#ifdef CHAR_IS_UNSIGNED
38
#define UCH(x) ((int) (x))
41
#define UCH(x) ((int) (x) & 0xFF)
43
#endif /* HAVE_UNSIGNED_CHAR */
46
#define ReadOK(file,buffer,len) (JFREAD(file,buffer,len) == ((size_t) (len)))
49
/* Private version of data source object */
51
typedef struct _bmp_source_struct * bmp_source_ptr;
53
typedef struct _bmp_source_struct {
54
struct cjpeg_source_struct pub; /* public fields */
56
j_compress_ptr cinfo; /* back link saves passing separate parm */
58
JSAMPARRAY colormap; /* BMP colormap (converted to my format) */
60
jvirt_sarray_ptr whole_image; /* Needed to reverse row order */
61
JDIMENSION source_row; /* Current source row number */
62
JDIMENSION row_width; /* Physical width of scanlines in file */
64
int bits_per_pixel; /* remembers 8- or 24-bit format */
69
read_byte (bmp_source_ptr sinfo)
70
/* Read next byte from BMP file */
72
register FILE *infile = sinfo->pub.input_file;
75
if ((c = getc(infile)) == EOF)
76
ERREXIT(sinfo->cinfo, JERR_INPUT_EOF);
82
read_colormap (bmp_source_ptr sinfo, int cmaplen, int mapentrysize)
83
/* Read the colormap from a BMP file */
87
switch (mapentrysize) {
89
/* BGR format (occurs in OS/2 files) */
90
for (i = 0; i < cmaplen; i++) {
91
sinfo->colormap[2][i] = (JSAMPLE) read_byte(sinfo);
92
sinfo->colormap[1][i] = (JSAMPLE) read_byte(sinfo);
93
sinfo->colormap[0][i] = (JSAMPLE) read_byte(sinfo);
97
/* BGR0 format (occurs in MS Windows files) */
98
for (i = 0; i < cmaplen; i++) {
99
sinfo->colormap[2][i] = (JSAMPLE) read_byte(sinfo);
100
sinfo->colormap[1][i] = (JSAMPLE) read_byte(sinfo);
101
sinfo->colormap[0][i] = (JSAMPLE) read_byte(sinfo);
102
(void) read_byte(sinfo);
106
ERREXIT(sinfo->cinfo, JERR_BMP_BADCMAP);
113
* Read one row of pixels.
114
* The image has been read into the whole_image array, but is otherwise
115
* unprocessed. We must read it out in top-to-bottom row order, and if
116
* it is an 8-bit image, we must expand colormapped pixels to 24bit format.
119
METHODDEF(JDIMENSION)
120
get_8bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
121
/* This version is for reading 8-bit colormap indexes */
123
bmp_source_ptr source = (bmp_source_ptr) sinfo;
124
register JSAMPARRAY colormap = source->colormap;
125
JSAMPARRAY image_ptr;
127
register JSAMPROW inptr, outptr;
128
register JDIMENSION col;
130
/* Fetch next row from virtual array */
131
source->source_row--;
132
image_ptr = (*cinfo->mem->access_virt_sarray)
133
((j_common_ptr) cinfo, source->whole_image,
134
source->source_row, (JDIMENSION) 1, FALSE);
136
/* Expand the colormap indexes to real data */
137
inptr = image_ptr[0];
138
outptr = source->pub.buffer[0];
139
for (col = cinfo->image_width; col > 0; col--) {
140
t = GETJSAMPLE(*inptr++);
141
*outptr++ = colormap[0][t]; /* can omit GETJSAMPLE() safely */
142
*outptr++ = colormap[1][t];
143
*outptr++ = colormap[2][t];
150
METHODDEF(JDIMENSION)
151
get_24bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
152
/* This version is for reading 24-bit pixels */
154
bmp_source_ptr source = (bmp_source_ptr) sinfo;
155
JSAMPARRAY image_ptr;
156
register JSAMPROW inptr, outptr;
157
register JDIMENSION col;
159
/* Fetch next row from virtual array */
160
source->source_row--;
161
image_ptr = (*cinfo->mem->access_virt_sarray)
162
((j_common_ptr) cinfo, source->whole_image,
163
source->source_row, (JDIMENSION) 1, FALSE);
165
/* Transfer data. Note source values are in BGR order
166
* (even though Microsoft's own documents say the opposite).
168
inptr = image_ptr[0];
169
outptr = source->pub.buffer[0];
170
for (col = cinfo->image_width; col > 0; col--) {
171
outptr[2] = *inptr++; /* can omit GETJSAMPLE() safely */
172
outptr[1] = *inptr++;
173
outptr[0] = *inptr++;
181
METHODDEF(JDIMENSION)
182
get_32bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
183
/* This version is for reading 32-bit pixels */
185
bmp_source_ptr source = (bmp_source_ptr) sinfo;
186
JSAMPARRAY image_ptr;
187
register JSAMPROW inptr, outptr;
188
register JDIMENSION col;
190
/* Fetch next row from virtual array */
191
source->source_row--;
192
image_ptr = (*cinfo->mem->access_virt_sarray)
193
((j_common_ptr) cinfo, source->whole_image,
194
source->source_row, (JDIMENSION) 1, FALSE);
195
/* Transfer data. Note source values are in BGR order
196
* (even though Microsoft's own documents say the opposite).
198
inptr = image_ptr[0];
199
outptr = source->pub.buffer[0];
200
for (col = cinfo->image_width; col > 0; col--) {
201
outptr[2] = *inptr++; /* can omit GETJSAMPLE() safely */
202
outptr[1] = *inptr++;
203
outptr[0] = *inptr++;
204
inptr++; /* skip the 4th byte (Alpha channel) */
213
* This method loads the image into whole_image during the first call on
214
* get_pixel_rows. The get_pixel_rows pointer is then adjusted to call
215
* get_8bit_row, get_24bit_row, or get_32bit_row on subsequent calls.
218
METHODDEF(JDIMENSION)
219
preload_image (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
221
bmp_source_ptr source = (bmp_source_ptr) sinfo;
222
register FILE *infile = source->pub.input_file;
224
register JSAMPROW out_ptr;
225
JSAMPARRAY image_ptr;
227
cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
229
/* Read the data into a virtual array in input-file row order. */
230
for (row = 0; row < cinfo->image_height; row++) {
231
if (progress != NULL) {
232
progress->pub.pass_counter = (long) row;
233
progress->pub.pass_limit = (long) cinfo->image_height;
234
(*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
236
image_ptr = (*cinfo->mem->access_virt_sarray)
237
((j_common_ptr) cinfo, source->whole_image,
238
row, (JDIMENSION) 1, TRUE);
239
out_ptr = image_ptr[0];
240
for (col = source->row_width; col > 0; col--) {
241
/* inline copy of read_byte() for speed */
242
if ((c = getc(infile)) == EOF)
243
ERREXIT(cinfo, JERR_INPUT_EOF);
244
*out_ptr++ = (JSAMPLE) c;
247
if (progress != NULL)
248
progress->completed_extra_passes++;
250
/* Set up to read from the virtual array in top-to-bottom order */
251
switch (source->bits_per_pixel) {
253
source->pub.get_pixel_rows = get_8bit_row;
256
source->pub.get_pixel_rows = get_24bit_row;
259
source->pub.get_pixel_rows = get_32bit_row;
262
ERREXIT(cinfo, JERR_BMP_BADDEPTH);
264
source->source_row = cinfo->image_height;
266
/* And read the first row */
267
return (*source->pub.get_pixel_rows) (cinfo, sinfo);
272
* Read the file header; return image size and component count.
276
start_input_bmp (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
278
bmp_source_ptr source = (bmp_source_ptr) sinfo;
279
U_CHAR bmpfileheader[14];
280
U_CHAR bmpinfoheader[64];
281
#define GET_2B(array,offset) ((unsigned int) UCH(array[offset]) + \
282
(((unsigned int) UCH(array[offset+1])) << 8))
283
#define GET_4B(array,offset) ((INT32) UCH(array[offset]) + \
284
(((INT32) UCH(array[offset+1])) << 8) + \
285
(((INT32) UCH(array[offset+2])) << 16) + \
286
(((INT32) UCH(array[offset+3])) << 24))
291
unsigned int biPlanes;
293
INT32 biXPelsPerMeter,biYPelsPerMeter;
295
int mapentrysize = 0; /* 0 indicates no colormap */
297
JDIMENSION row_width;
299
/* Read and verify the bitmap file header */
300
if (! ReadOK(source->pub.input_file, bmpfileheader, 14))
301
ERREXIT(cinfo, JERR_INPUT_EOF);
302
if (GET_2B(bmpfileheader,0) != 0x4D42) /* 'BM' */
303
ERREXIT(cinfo, JERR_BMP_NOT);
304
bfOffBits = (INT32) GET_4B(bmpfileheader,10);
305
/* We ignore the remaining fileheader fields */
307
/* The infoheader might be 12 bytes (OS/2 1.x), 40 bytes (Windows),
308
* or 64 bytes (OS/2 2.x). Check the first 4 bytes to find out which.
310
if (! ReadOK(source->pub.input_file, bmpinfoheader, 4))
311
ERREXIT(cinfo, JERR_INPUT_EOF);
312
headerSize = (INT32) GET_4B(bmpinfoheader,0);
313
if (headerSize < 12 || headerSize > 64)
314
ERREXIT(cinfo, JERR_BMP_BADHEADER);
315
if (! ReadOK(source->pub.input_file, bmpinfoheader+4, headerSize-4))
316
ERREXIT(cinfo, JERR_INPUT_EOF);
318
switch ((int) headerSize) {
320
/* Decode OS/2 1.x header (Microsoft calls this a BITMAPCOREHEADER) */
321
biWidth = (INT32) GET_2B(bmpinfoheader,4);
322
biHeight = (INT32) GET_2B(bmpinfoheader,6);
323
biPlanes = GET_2B(bmpinfoheader,8);
324
source->bits_per_pixel = (int) GET_2B(bmpinfoheader,10);
326
switch (source->bits_per_pixel) {
327
case 8: /* colormapped image */
328
mapentrysize = 3; /* OS/2 uses RGBTRIPLE colormap */
329
TRACEMS2(cinfo, 1, JTRC_BMP_OS2_MAPPED, (int) biWidth, (int) biHeight);
331
case 24: /* RGB image */
332
TRACEMS2(cinfo, 1, JTRC_BMP_OS2, (int) biWidth, (int) biHeight);
335
ERREXIT(cinfo, JERR_BMP_BADDEPTH);
341
/* Decode Windows 3.x header (Microsoft calls this a BITMAPINFOHEADER) */
342
/* or OS/2 2.x header, which has additional fields that we ignore */
343
biWidth = GET_4B(bmpinfoheader,4);
344
biHeight = GET_4B(bmpinfoheader,8);
345
biPlanes = GET_2B(bmpinfoheader,12);
346
source->bits_per_pixel = (int) GET_2B(bmpinfoheader,14);
347
biCompression = GET_4B(bmpinfoheader,16);
348
biXPelsPerMeter = GET_4B(bmpinfoheader,24);
349
biYPelsPerMeter = GET_4B(bmpinfoheader,28);
350
biClrUsed = GET_4B(bmpinfoheader,32);
351
/* biSizeImage, biClrImportant fields are ignored */
353
switch (source->bits_per_pixel) {
354
case 8: /* colormapped image */
355
mapentrysize = 4; /* Windows uses RGBQUAD colormap */
356
TRACEMS2(cinfo, 1, JTRC_BMP_MAPPED, (int) biWidth, (int) biHeight);
358
case 24: /* RGB image */
359
TRACEMS2(cinfo, 1, JTRC_BMP, (int) biWidth, (int) biHeight);
361
case 32: /* RGB image + Alpha channel */
362
TRACEMS2(cinfo, 1, JTRC_BMP, (int) biWidth, (int) biHeight);
365
ERREXIT(cinfo, JERR_BMP_BADDEPTH);
368
if (biCompression != 0)
369
ERREXIT(cinfo, JERR_BMP_COMPRESSED);
371
if (biXPelsPerMeter > 0 && biYPelsPerMeter > 0) {
372
/* Set JFIF density parameters from the BMP data */
373
cinfo->X_density = (UINT16) (biXPelsPerMeter/100); /* 100 cm per meter */
374
cinfo->Y_density = (UINT16) (biYPelsPerMeter/100);
375
cinfo->density_unit = 2; /* dots/cm */
379
ERREXIT(cinfo, JERR_BMP_BADHEADER);
383
if (biWidth <= 0 || biHeight <= 0)
384
ERREXIT(cinfo, JERR_BMP_EMPTY);
386
ERREXIT(cinfo, JERR_BMP_BADPLANES);
388
/* Compute distance to bitmap data --- will adjust for colormap below */
389
bPad = bfOffBits - (headerSize + 14);
391
/* Read the colormap, if any */
392
if (mapentrysize > 0) {
394
biClrUsed = 256; /* assume it's 256 */
395
else if (biClrUsed > 256)
396
ERREXIT(cinfo, JERR_BMP_BADCMAP);
397
/* Allocate space to store the colormap */
398
source->colormap = (*cinfo->mem->alloc_sarray)
399
((j_common_ptr) cinfo, JPOOL_IMAGE,
400
(JDIMENSION) biClrUsed, (JDIMENSION) 3);
401
/* and read it from the file */
402
read_colormap(source, (int) biClrUsed, mapentrysize);
403
/* account for size of colormap */
404
bPad -= biClrUsed * mapentrysize;
407
/* Skip any remaining pad bytes */
408
if (bPad < 0) /* incorrect bfOffBits value? */
409
ERREXIT(cinfo, JERR_BMP_BADHEADER);
410
while (--bPad >= 0) {
411
(void) read_byte(source);
414
/* Compute row width in file, including padding to 4-byte boundary */
415
if (source->bits_per_pixel == 24)
416
row_width = (JDIMENSION) (biWidth * 3);
417
else if (source->bits_per_pixel == 32)
418
row_width = (JDIMENSION) (biWidth * 4);
420
row_width = (JDIMENSION) biWidth;
421
while ((row_width & 3) != 0) row_width++;
422
source->row_width = row_width;
424
/* Allocate space for inversion array, prepare for preload pass */
425
source->whole_image = (*cinfo->mem->request_virt_sarray)
426
((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
427
row_width, (JDIMENSION) biHeight, (JDIMENSION) 1);
428
source->pub.get_pixel_rows = preload_image;
429
if (cinfo->progress != NULL) {
430
cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
431
progress->total_extra_passes++; /* count file input as separate pass */
434
/* Allocate one-row buffer for returned data */
435
source->pub.buffer = (*cinfo->mem->alloc_sarray)
436
((j_common_ptr) cinfo, JPOOL_IMAGE,
437
(JDIMENSION) (biWidth * 3), (JDIMENSION) 1);
438
source->pub.buffer_height = 1;
440
cinfo->in_color_space = JCS_RGB;
441
cinfo->input_components = 3;
442
cinfo->data_precision = 8;
443
cinfo->image_width = (JDIMENSION) biWidth;
444
cinfo->image_height = (JDIMENSION) biHeight;
449
* Finish up at the end of the file.
453
finish_input_bmp (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
460
* The module selection routine for BMP format input.
463
GLOBAL(cjpeg_source_ptr)
464
jinit_read_bmp (j_compress_ptr cinfo)
466
bmp_source_ptr source;
468
/* Create module interface object */
469
source = (bmp_source_ptr)
470
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
471
SIZEOF(bmp_source_struct));
472
source->cinfo = cinfo; /* make back link for subroutines */
473
/* Fill in method ptrs, except get_pixel_rows which start_input sets */
474
source->pub.start_input = start_input_bmp;
475
source->pub.finish_input = finish_input_bmp;
477
return (cjpeg_source_ptr) source;
480
#endif /* BMP_SUPPORTED */