1 /*
2 * wrbmp.c
3 *
4 * Copyright (C) 1994-1996, 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 write output images in Microsoft "BMP"
9 * format (MS Windows 3.x and OS/2 1.x flavors).
10 * Either 8-bit colormapped or 24-bit full-color format can be written.
11 * No compression is supported.
12 *
13 * These routines may need modification for non-Unix environments or
14 * specialized applications. As they stand, they assume output to
15 * an ordinary stdio stream.
16 *
17 * This code contributed by James Arthur Boucher.
18 */
19
20 #include "cdjpeg.h" /* Common decls for cjpeg/djpeg applications */
21
22 #ifdef BMP_SUPPORTED
23
24
25 /*
26 * To support 12-bit JPEG data, we'd have to scale output down to 8 bits.
27 * This is not yet implemented.
28 */
29
30 #if BITS_IN_JSAMPLE != 8
31 Sorry, this code only copes with 8-bit JSAMPLEs. /* deliberate syntax err */
32 #endif
33
34 /*
35 * Since BMP stores scanlines bottom-to-top, we have to invert the image
36 * from JPEG's top-to-bottom order. To do this, we save the outgoing data
37 * in a virtual array during put_pixel_row calls, then actually emit the
38 * BMP file during finish_output. The virtual array contains one JSAMPLE per
39 * pixel if the output is grayscale or colormapped, three if it is full color.
40 */
41
42 /* Private version of data destination object */
43
44 typedef struct {
45 struct djpeg_dest_struct pub; /* public fields */
46
47 boolean is_os2; /* saves the OS2 format request flag */
48
49 jvirt_sarray_ptr whole_image; /* needed to reverse row order */
50 JDIMENSION data_width; /* JSAMPLEs per row */
51 JDIMENSION row_width; /* physical width of one row in the BMP file */
52 int pad_bytes; /* number of padding bytes needed per row */
53 JDIMENSION cur_output_row; /* next row# to write to virtual array */
54 } bmp_dest_struct;
55
56 typedef bmp_dest_struct * bmp_dest_ptr;
57
58
59 /* Forward declarations */
60 LOCAL(void) write_colormap
61 JPP((j_decompress_ptr cinfo, bmp_dest_ptr dest,
62 int map_colors, int map_entry_size));
63
64
65 /*
66 * Write some pixel data.
67 * In this module rows_supplied will always be 1.
68 */
69
70 METHODDEF(void)
put_pixel_rows(j_decompress_ptr cinfo,djpeg_dest_ptr dinfo,JDIMENSION rows_supplied)71 put_pixel_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
72 JDIMENSION rows_supplied)
73 /* This version is for writing 24-bit pixels */
74 {
75 bmp_dest_ptr dest = (bmp_dest_ptr) dinfo;
76 JSAMPARRAY image_ptr;
77 register JSAMPROW inptr, outptr;
78 register JDIMENSION col;
79 int pad;
80
81 /* Access next row in virtual array */
82 image_ptr = (*cinfo->mem->access_virt_sarray)
83 ((j_common_ptr) cinfo, dest->whole_image,
84 dest->cur_output_row, (JDIMENSION) 1, TRUE);
85 dest->cur_output_row++;
86
87 /* Transfer data. Note destination values must be in BGR order
88 * (even though Microsoft's own documents say the opposite).
89 */
90 inptr = dest->pub.buffer[0];
91 outptr = image_ptr[0];
92 for (col = cinfo->output_width; col > 0; col--) {
93 outptr[2] = *inptr++; /* can omit GETJSAMPLE() safely */
94 outptr[1] = *inptr++;
95 outptr[0] = *inptr++;
96 outptr += 3;
97 }
98
99 /* Zero out the pad bytes. */
100 pad = dest->pad_bytes;
101 while (--pad >= 0)
102 *outptr++ = 0;
103 }
104
105 METHODDEF(void)
put_gray_rows(j_decompress_ptr cinfo,djpeg_dest_ptr dinfo,JDIMENSION rows_supplied)106 put_gray_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
107 JDIMENSION rows_supplied)
108 /* This version is for grayscale OR quantized color output */
109 {
110 bmp_dest_ptr dest = (bmp_dest_ptr) dinfo;
111 JSAMPARRAY image_ptr;
112 register JSAMPROW inptr, outptr;
113 register JDIMENSION col;
114 int pad;
115
116 /* Access next row in virtual array */
117 image_ptr = (*cinfo->mem->access_virt_sarray)
118 ((j_common_ptr) cinfo, dest->whole_image,
119 dest->cur_output_row, (JDIMENSION) 1, TRUE);
120 dest->cur_output_row++;
121
122 /* Transfer data. */
123 inptr = dest->pub.buffer[0];
124 outptr = image_ptr[0];
125 for (col = cinfo->output_width; col > 0; col--) {
126 *outptr++ = *inptr++; /* can omit GETJSAMPLE() safely */
127 }
128
129 /* Zero out the pad bytes. */
130 pad = dest->pad_bytes;
131 while (--pad >= 0)
132 *outptr++ = 0;
133 }
134
135
136 /*
137 * Startup: normally writes the file header.
138 * In this module we may as well postpone everything until finish_output.
139 */
140
141 METHODDEF(void)
start_output_bmp(j_decompress_ptr cinfo,djpeg_dest_ptr dinfo)142 start_output_bmp (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
143 {
144 /* no work here */
145 }
146
147
148 /*
149 * Finish up at the end of the file.
150 *
151 * Here is where we really output the BMP file.
152 *
153 * First, routines to write the Windows and OS/2 variants of the file header.
154 */
155
156 LOCAL(void)
write_bmp_header(j_decompress_ptr cinfo,bmp_dest_ptr dest)157 write_bmp_header (j_decompress_ptr cinfo, bmp_dest_ptr dest)
158 /* Write a Windows-style BMP file header, including colormap if needed */
159 {
160 char bmpfileheader[14];
161 char bmpinfoheader[40];
162 #define PUT_2B(array,offset,value) \
163 (array[offset] = (char) ((value) & 0xFF), \
164 array[offset+1] = (char) (((value) >> 8) & 0xFF))
165 #define PUT_4B(array,offset,value) \
166 (array[offset] = (char) ((value) & 0xFF), \
167 array[offset+1] = (char) (((value) >> 8) & 0xFF), \
168 array[offset+2] = (char) (((value) >> 16) & 0xFF), \
169 array[offset+3] = (char) (((value) >> 24) & 0xFF))
170 INT32 headersize, bfSize;
171 int bits_per_pixel, cmap_entries;
172
173 /* Compute colormap size and total file size */
174 if (cinfo->out_color_space == JCS_RGB) {
175 if (cinfo->quantize_colors) {
176 /* Colormapped RGB */
177 bits_per_pixel = 8;
178 cmap_entries = 256;
179 } else {
180 /* Unquantized, full color RGB */
181 bits_per_pixel = 24;
182 cmap_entries = 0;
183 }
184 } else {
185 /* Grayscale output. We need to fake a 256-entry colormap. */
186 bits_per_pixel = 8;
187 cmap_entries = 256;
188 }
189 /* File size */
190 headersize = 14 + 40 + cmap_entries * 4; /* Header and colormap */
191 bfSize = headersize + (INT32) dest->row_width * (INT32) cinfo->output_height;
192
193 /* Set unused fields of header to 0 */
194 MEMZERO(bmpfileheader, SIZEOF(bmpfileheader));
195 MEMZERO(bmpinfoheader, SIZEOF(bmpinfoheader));
196
197 /* Fill the file header */
198 bmpfileheader[0] = 0x42; /* first 2 bytes are ASCII 'B', 'M' */
199 bmpfileheader[1] = 0x4D;
200 PUT_4B(bmpfileheader, 2, bfSize); /* bfSize */
201 /* we leave bfReserved1 & bfReserved2 = 0 */
202 PUT_4B(bmpfileheader, 10, headersize); /* bfOffBits */
203
204 /* Fill the info header (Microsoft calls this a BITMAPINFOHEADER) */
205 PUT_2B(bmpinfoheader, 0, 40); /* biSize */
206 PUT_4B(bmpinfoheader, 4, cinfo->output_width); /* biWidth */
207 PUT_4B(bmpinfoheader, 8, cinfo->output_height); /* biHeight */
208 PUT_2B(bmpinfoheader, 12, 1); /* biPlanes - must be 1 */
209 PUT_2B(bmpinfoheader, 14, bits_per_pixel); /* biBitCount */
210 /* we leave biCompression = 0, for none */
211 /* we leave biSizeImage = 0; this is correct for uncompressed data */
212 if (cinfo->density_unit == 2) { /* if have density in dots/cm, then */
213 PUT_4B(bmpinfoheader, 24, (INT32) (cinfo->X_density*100)); /* XPels/M */
214 PUT_4B(bmpinfoheader, 28, (INT32) (cinfo->Y_density*100)); /* XPels/M */
215 }
216 PUT_2B(bmpinfoheader, 32, cmap_entries); /* biClrUsed */
217 /* we leave biClrImportant = 0 */
218
219 if (JFWRITE(dest->pub.output_file, bmpfileheader, 14) != (size_t) 14)
220 ERREXIT(cinfo, JERR_FILE_WRITE);
221 if (JFWRITE(dest->pub.output_file, bmpinfoheader, 40) != (size_t) 40)
222 ERREXIT(cinfo, JERR_FILE_WRITE);
223
224 if (cmap_entries > 0)
225 write_colormap(cinfo, dest, cmap_entries, 4);
226 }
227
228
229 LOCAL(void)
write_os2_header(j_decompress_ptr cinfo,bmp_dest_ptr dest)230 write_os2_header (j_decompress_ptr cinfo, bmp_dest_ptr dest)
231 /* Write an OS2-style BMP file header, including colormap if needed */
232 {
233 char bmpfileheader[14];
234 char bmpcoreheader[12];
235 INT32 headersize, bfSize;
236 int bits_per_pixel, cmap_entries;
237
238 /* Compute colormap size and total file size */
239 if (cinfo->out_color_space == JCS_RGB) {
240 if (cinfo->quantize_colors) {
241 /* Colormapped RGB */
242 bits_per_pixel = 8;
243 cmap_entries = 256;
244 } else {
245 /* Unquantized, full color RGB */
246 bits_per_pixel = 24;
247 cmap_entries = 0;
248 }
249 } else {
250 /* Grayscale output. We need to fake a 256-entry colormap. */
251 bits_per_pixel = 8;
252 cmap_entries = 256;
253 }
254 /* File size */
255 headersize = 14 + 12 + cmap_entries * 3; /* Header and colormap */
256 bfSize = headersize + (INT32) dest->row_width * (INT32) cinfo->output_height;
257
258 /* Set unused fields of header to 0 */
259 MEMZERO(bmpfileheader, SIZEOF(bmpfileheader));
260 MEMZERO(bmpcoreheader, SIZEOF(bmpcoreheader));
261
262 /* Fill the file header */
263 bmpfileheader[0] = 0x42; /* first 2 bytes are ASCII 'B', 'M' */
264 bmpfileheader[1] = 0x4D;
265 PUT_4B(bmpfileheader, 2, bfSize); /* bfSize */
266 /* we leave bfReserved1 & bfReserved2 = 0 */
267 PUT_4B(bmpfileheader, 10, headersize); /* bfOffBits */
268
269 /* Fill the info header (Microsoft calls this a BITMAPCOREHEADER) */
270 PUT_2B(bmpcoreheader, 0, 12); /* bcSize */
271 PUT_2B(bmpcoreheader, 4, cinfo->output_width); /* bcWidth */
272 PUT_2B(bmpcoreheader, 6, cinfo->output_height); /* bcHeight */
273 PUT_2B(bmpcoreheader, 8, 1); /* bcPlanes - must be 1 */
274 PUT_2B(bmpcoreheader, 10, bits_per_pixel); /* bcBitCount */
275
276 if (JFWRITE(dest->pub.output_file, bmpfileheader, 14) != (size_t) 14)
277 ERREXIT(cinfo, JERR_FILE_WRITE);
278 if (JFWRITE(dest->pub.output_file, bmpcoreheader, 12) != (size_t) 12)
279 ERREXIT(cinfo, JERR_FILE_WRITE);
280
281 if (cmap_entries > 0)
282 write_colormap(cinfo, dest, cmap_entries, 3);
283 }
284
285
286 /*
287 * Write the colormap.
288 * Windows uses BGR0 map entries; OS/2 uses BGR entries.
289 */
290
291 LOCAL(void)
write_colormap(j_decompress_ptr cinfo,bmp_dest_ptr dest,int map_colors,int map_entry_size)292 write_colormap (j_decompress_ptr cinfo, bmp_dest_ptr dest,
293 int map_colors, int map_entry_size)
294 {
295 JSAMPARRAY colormap = cinfo->colormap;
296 int num_colors = cinfo->actual_number_of_colors;
297 FILE * outfile = dest->pub.output_file;
298 int i;
299
300 if (colormap != NULL) {
301 if (cinfo->out_color_components == 3) {
302 /* Normal case with RGB colormap */
303 for (i = 0; i < num_colors; i++) {
304 putc(GETJSAMPLE(colormap[2][i]), outfile);
305 putc(GETJSAMPLE(colormap[1][i]), outfile);
306 putc(GETJSAMPLE(colormap[0][i]), outfile);
307 if (map_entry_size == 4)
308 putc(0, outfile);
309 }
310 } else {
311 /* Grayscale colormap (only happens with grayscale quantization) */
312 for (i = 0; i < num_colors; i++) {
313 putc(GETJSAMPLE(colormap[0][i]), outfile);
314 putc(GETJSAMPLE(colormap[0][i]), outfile);
315 putc(GETJSAMPLE(colormap[0][i]), outfile);
316 if (map_entry_size == 4)
317 putc(0, outfile);
318 }
319 }
320 } else {
321 /* If no colormap, must be grayscale data. Generate a linear "map". */
322 for (i = 0; i < 256; i++) {
323 putc(i, outfile);
324 putc(i, outfile);
325 putc(i, outfile);
326 if (map_entry_size == 4)
327 putc(0, outfile);
328 }
329 }
330 /* Pad colormap with zeros to ensure specified number of colormap entries */
331 if (i > map_colors)
332 ERREXIT1(cinfo, JERR_TOO_MANY_COLORS, i);
333 for (; i < map_colors; i++) {
334 putc(0, outfile);
335 putc(0, outfile);
336 putc(0, outfile);
337 if (map_entry_size == 4)
338 putc(0, outfile);
339 }
340 }
341
342
343 METHODDEF(void)
finish_output_bmp(j_decompress_ptr cinfo,djpeg_dest_ptr dinfo)344 finish_output_bmp (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
345 {
346 bmp_dest_ptr dest = (bmp_dest_ptr) dinfo;
347 register FILE * outfile = dest->pub.output_file;
348 JSAMPARRAY image_ptr;
349 register JSAMPROW data_ptr;
350 JDIMENSION row;
351 register JDIMENSION col;
352 cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
353
354 /* Write the header and colormap */
355 if (dest->is_os2)
356 write_os2_header(cinfo, dest);
357 else
358 write_bmp_header(cinfo, dest);
359
360 /* Write the file body from our virtual array */
361 for (row = cinfo->output_height; row > 0; row--) {
362 if (progress != NULL) {
363 progress->pub.pass_counter = (long) (cinfo->output_height - row);
364 progress->pub.pass_limit = (long) cinfo->output_height;
365 (*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
366 }
367 image_ptr = (*cinfo->mem->access_virt_sarray)
368 ((j_common_ptr) cinfo, dest->whole_image, row-1, (JDIMENSION) 1, FALSE);
369 data_ptr = image_ptr[0];
370 for (col = dest->row_width; col > 0; col--) {
371 putc(GETJSAMPLE(*data_ptr), outfile);
372 data_ptr++;
373 }
374 }
375 if (progress != NULL)
376 progress->completed_extra_passes++;
377
378 /* Make sure we wrote the output file OK */
379 fflush(outfile);
380 if (ferror(outfile))
381 ERREXIT(cinfo, JERR_FILE_WRITE);
382 }
383
384
385 /*
386 * The module selection routine for BMP format output.
387 */
388
389 GLOBAL(djpeg_dest_ptr)
jinit_write_bmp(j_decompress_ptr cinfo,boolean is_os2)390 jinit_write_bmp (j_decompress_ptr cinfo, boolean is_os2)
391 {
392 bmp_dest_ptr dest;
393 JDIMENSION row_width;
394
395 /* Create module interface object, fill in method pointers */
396 dest = (bmp_dest_ptr)
397 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
398 SIZEOF(bmp_dest_struct));
399 dest->pub.start_output = start_output_bmp;
400 dest->pub.finish_output = finish_output_bmp;
401 dest->is_os2 = is_os2;
402
403 if (cinfo->out_color_space == JCS_GRAYSCALE) {
404 dest->pub.put_pixel_rows = put_gray_rows;
405 } else if (cinfo->out_color_space == JCS_RGB) {
406 if (cinfo->quantize_colors)
407 dest->pub.put_pixel_rows = put_gray_rows;
408 else
409 dest->pub.put_pixel_rows = put_pixel_rows;
410 } else {
411 ERREXIT(cinfo, JERR_BMP_COLORSPACE);
412 }
413
414 /* Calculate output image dimensions so we can allocate space */
415 jpeg_calc_output_dimensions(cinfo);
416
417 /* Determine width of rows in the BMP file (padded to 4-byte boundary). */
418 row_width = cinfo->output_width * cinfo->output_components;
419 dest->data_width = row_width;
420 while ((row_width & 3) != 0) row_width++;
421 dest->row_width = row_width;
422 dest->pad_bytes = (int) (row_width - dest->data_width);
423
424 /* Allocate space for inversion array, prepare for write pass */
425 dest->whole_image = (*cinfo->mem->request_virt_sarray)
426 ((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
427 row_width, cinfo->output_height, (JDIMENSION) 1);
428 dest->cur_output_row = 0;
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 */
432 }
433
434 /* Create decompressor output buffer. */
435 dest->pub.buffer = (*cinfo->mem->alloc_sarray)
436 ((j_common_ptr) cinfo, JPOOL_IMAGE, row_width, (JDIMENSION) 1);
437 dest->pub.buffer_height = 1;
438
439 return (djpeg_dest_ptr) dest;
440 }
441
442 #endif /* BMP_SUPPORTED */
443