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
44typedef 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
56typedef bmp_dest_struct * bmp_dest_ptr;
57
58
59/* Forward declarations */
60LOCAL(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
70METHODDEF(void)
71put_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
105METHODDEF(void)
106put_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
141METHODDEF(void)
142start_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
156LOCAL(void)
157write_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
229LOCAL(void)
230write_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
291LOCAL(void)
292write_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
343METHODDEF(void)
344finish_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
389GLOBAL(djpeg_dest_ptr)
390jinit_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