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