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      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)
     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)
    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)
    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)
    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)
    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)
    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)
    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)
    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