third_party/libjpeg-turbo/rdbmp.c - cobalt - Git at Google

 /*
  * rdbmp.c
  *
  * This file was part of the Independent JPEG Group's software:
  * Copyright (C) 1994-1996, Thomas G. Lane.
  * Modified 2009-2017 by Guido Vollbeding.
  * libjpeg-turbo Modifications:
  * Modified 2011 by Siarhei Siamashka.
  * Copyright (C) 2015, 2017-2018, 2021, D. R. Commander.
  * For conditions of distribution and use, see the accompanying README.ijg
  * file.
  *
  * This file contains routines to read input images in Microsoft "BMP"
  * format (MS Windows 3.x, OS/2 1.x, and OS/2 2.x flavors).
  * Currently, only 8-, 24-, and 32-bit images are supported, not 1-bit or
  * 4-bit (feeding such low-depth images into JPEG would be silly anyway).
  * Also, we don't support RLE-compressed files.
  *
  * These routines may need modification for non-Unix environments or
  * specialized applications.  As they stand, they assume input from
  * an ordinary stdio stream.  They further assume that reading begins
  * at the start of the file; start_input may need work if the
  * user interface has already read some data (e.g., to determine that
  * the file is indeed BMP format).
  *
  * This code contributed by James Arthur Boucher.
  */

 #include "cmyk.h"
 #include "cdjpeg.h"             /* Common decls for cjpeg/djpeg applications */

 #ifdef BMP_SUPPORTED


 /* Macros to deal with unsigned chars as efficiently as compiler allows */

 typedef unsigned char U_CHAR;
 #define UCH(x)  ((int)(x))


 #define ReadOK(file, buffer, len) \
   (JFREAD(file, buffer, len) == ((size_t)(len)))

 static int alpha_index[JPEG_NUMCS] = {
   -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 3, 3, 0, 0, -1
 };


 /* Private version of data source object */

 typedef struct _bmp_source_struct *bmp_source_ptr;

 typedef struct _bmp_source_struct {
   struct cjpeg_source_struct pub; /* public fields */

   j_compress_ptr cinfo;         /* back link saves passing separate parm */

   JSAMPARRAY colormap;          /* BMP colormap (converted to my format) */

   jvirt_sarray_ptr whole_image; /* Needed to reverse row order */
   JDIMENSION source_row;        /* Current source row number */
   JDIMENSION row_width;         /* Physical width of scanlines in file */

   int bits_per_pixel;           /* remembers 8-, 24-, or 32-bit format */
   int cmap_length;              /* colormap length */

   boolean use_inversion_array;  /* TRUE = preload the whole image, which is
                                    stored in bottom-up order, and feed it to
                                    the calling program in top-down order

                                    FALSE = the calling program will maintain
                                    its own image buffer and read the rows in
                                    bottom-up order */

   U_CHAR *iobuffer;             /* I/O buffer (used to buffer a single row from
                                    disk if use_inversion_array == FALSE) */
 } bmp_source_struct;


 LOCAL(int)
 read_byte(bmp_source_ptr sinfo)
 /* Read next byte from BMP file */
 {
   register FILE *infile = sinfo->pub.input_file;
   register int c;

   if ((c = getc(infile)) == EOF)
     ERREXIT(sinfo->cinfo, JERR_INPUT_EOF);
   return c;
 }


 LOCAL(void)
 read_colormap(bmp_source_ptr sinfo, int cmaplen, int mapentrysize)
 /* Read the colormap from a BMP file */
 {
   int i, gray = 1;

   switch (mapentrysize) {
   case 3:
     /* BGR format (occurs in OS/2 files) */
     for (i = 0; i < cmaplen; i++) {
       sinfo->colormap[2][i] = (JSAMPLE)read_byte(sinfo);
       sinfo->colormap[1][i] = (JSAMPLE)read_byte(sinfo);
       sinfo->colormap[0][i] = (JSAMPLE)read_byte(sinfo);
       if (sinfo->colormap[2][i] != sinfo->colormap[1][i] ||
           sinfo->colormap[1][i] != sinfo->colormap[0][i])
         gray = 0;
     }
     break;
   case 4:
     /* BGR0 format (occurs in MS Windows files) */
     for (i = 0; i < cmaplen; i++) {
       sinfo->colormap[2][i] = (JSAMPLE)read_byte(sinfo);
       sinfo->colormap[1][i] = (JSAMPLE)read_byte(sinfo);
       sinfo->colormap[0][i] = (JSAMPLE)read_byte(sinfo);
       (void)read_byte(sinfo);
       if (sinfo->colormap[2][i] != sinfo->colormap[1][i] ||
           sinfo->colormap[1][i] != sinfo->colormap[0][i])
         gray = 0;
     }
     break;
   default:
     ERREXIT(sinfo->cinfo, JERR_BMP_BADCMAP);
     break;
   }

   if (sinfo->cinfo->in_color_space == JCS_UNKNOWN && gray)
     sinfo->cinfo->in_color_space = JCS_GRAYSCALE;

   if (sinfo->cinfo->in_color_space == JCS_GRAYSCALE && !gray)
     ERREXIT(sinfo->cinfo, JERR_BAD_IN_COLORSPACE);
 }


 /*
  * Read one row of pixels.
  * The image has been read into the whole_image array, but is otherwise
  * unprocessed.  We must read it out in top-to-bottom row order, and if
  * it is an 8-bit image, we must expand colormapped pixels to 24bit format.
  */

 METHODDEF(JDIMENSION)
 get_8bit_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
 /* This version is for reading 8-bit colormap indexes */
 {
   bmp_source_ptr source = (bmp_source_ptr)sinfo;
   register JSAMPARRAY colormap = source->colormap;
   int cmaplen = source->cmap_length;
   JSAMPARRAY image_ptr;
   register int t;
   register JSAMPROW inptr, outptr;
   register JDIMENSION col;

   if (source->use_inversion_array) {
     /* Fetch next row from virtual array */
     source->source_row--;
     image_ptr = (*cinfo->mem->access_virt_sarray)
       ((j_common_ptr)cinfo, source->whole_image,
        source->source_row, (JDIMENSION)1, FALSE);
     inptr = image_ptr[0];
   } else {
     if (!ReadOK(source->pub.input_file, source->iobuffer, source->row_width))
       ERREXIT(cinfo, JERR_INPUT_EOF);
     inptr = source->iobuffer;
   }

   /* Expand the colormap indexes to real data */
   outptr = source->pub.buffer[0];
   if (cinfo->in_color_space == JCS_GRAYSCALE) {
     for (col = cinfo->image_width; col > 0; col--) {
       t = *inptr++;
       if (t >= cmaplen)
         ERREXIT(cinfo, JERR_BMP_OUTOFRANGE);
       *outptr++ = colormap[0][t];
     }
   } else if (cinfo->in_color_space == JCS_CMYK) {
     for (col = cinfo->image_width; col > 0; col--) {
       t = *inptr++;
       if (t >= cmaplen)
         ERREXIT(cinfo, JERR_BMP_OUTOFRANGE);
       rgb_to_cmyk(colormap[0][t], colormap[1][t], colormap[2][t], outptr,
                   outptr + 1, outptr + 2, outptr + 3);
       outptr += 4;
     }
   } else {
     register int rindex = rgb_red[cinfo->in_color_space];
     register int gindex = rgb_green[cinfo->in_color_space];
     register int bindex = rgb_blue[cinfo->in_color_space];
     register int aindex = alpha_index[cinfo->in_color_space];
     register int ps = rgb_pixelsize[cinfo->in_color_space];

     if (aindex >= 0) {
       for (col = cinfo->image_width; col > 0; col--) {
         t = *inptr++;
         if (t >= cmaplen)
           ERREXIT(cinfo, JERR_BMP_OUTOFRANGE);
         outptr[rindex] = colormap[0][t];
         outptr[gindex] = colormap[1][t];
         outptr[bindex] = colormap[2][t];
         outptr[aindex] = 0xFF;
         outptr += ps;
       }
     } else {
       for (col = cinfo->image_width; col > 0; col--) {
         t = *inptr++;
         if (t >= cmaplen)
           ERREXIT(cinfo, JERR_BMP_OUTOFRANGE);
         outptr[rindex] = colormap[0][t];
         outptr[gindex] = colormap[1][t];
         outptr[bindex] = colormap[2][t];
         outptr += ps;
       }
     }
   }

   return 1;
 }


 METHODDEF(JDIMENSION)
 get_24bit_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
 /* This version is for reading 24-bit pixels */
 {
   bmp_source_ptr source = (bmp_source_ptr)sinfo;
   JSAMPARRAY image_ptr;
   register JSAMPROW inptr, outptr;
   register JDIMENSION col;

   if (source->use_inversion_array) {
     /* Fetch next row from virtual array */
     source->source_row--;
     image_ptr = (*cinfo->mem->access_virt_sarray)
       ((j_common_ptr)cinfo, source->whole_image,
        source->source_row, (JDIMENSION)1, FALSE);
     inptr = image_ptr[0];
   } else {
     if (!ReadOK(source->pub.input_file, source->iobuffer, source->row_width))
       ERREXIT(cinfo, JERR_INPUT_EOF);
     inptr = source->iobuffer;
   }

   /* Transfer data.  Note source values are in BGR order
    * (even though Microsoft's own documents say the opposite).
    */
   outptr = source->pub.buffer[0];
   if (cinfo->in_color_space == JCS_EXT_BGR) {
     MEMCOPY(outptr, inptr, source->row_width);
   } else if (cinfo->in_color_space == JCS_CMYK) {
     for (col = cinfo->image_width; col > 0; col--) {
       JSAMPLE b = *inptr++, g = *inptr++, r = *inptr++;
       rgb_to_cmyk(r, g, b, outptr, outptr + 1, outptr + 2, outptr + 3);
       outptr += 4;
     }
   } else {
     register int rindex = rgb_red[cinfo->in_color_space];
     register int gindex = rgb_green[cinfo->in_color_space];
     register int bindex = rgb_blue[cinfo->in_color_space];
     register int aindex = alpha_index[cinfo->in_color_space];
     register int ps = rgb_pixelsize[cinfo->in_color_space];

     if (aindex >= 0) {
       for (col = cinfo->image_width; col > 0; col--) {
         outptr[bindex] = *inptr++;
         outptr[gindex] = *inptr++;
         outptr[rindex] = *inptr++;
         outptr[aindex] = 0xFF;
         outptr += ps;
       }
     } else {
       for (col = cinfo->image_width; col > 0; col--) {
         outptr[bindex] = *inptr++;
         outptr[gindex] = *inptr++;
         outptr[rindex] = *inptr++;
         outptr += ps;
       }
     }
   }

   return 1;
 }


 METHODDEF(JDIMENSION)
 get_32bit_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
 /* This version is for reading 32-bit pixels */
 {
   bmp_source_ptr source = (bmp_source_ptr)sinfo;
   JSAMPARRAY image_ptr;
   register JSAMPROW inptr, outptr;
   register JDIMENSION col;

   if (source->use_inversion_array) {
     /* Fetch next row from virtual array */
     source->source_row--;
     image_ptr = (*cinfo->mem->access_virt_sarray)
       ((j_common_ptr)cinfo, source->whole_image,
        source->source_row, (JDIMENSION)1, FALSE);
     inptr = image_ptr[0];
   } else {
     if (!ReadOK(source->pub.input_file, source->iobuffer, source->row_width))
       ERREXIT(cinfo, JERR_INPUT_EOF);
     inptr = source->iobuffer;
   }

   /* Transfer data.  Note source values are in BGR order
    * (even though Microsoft's own documents say the opposite).
    */
   outptr = source->pub.buffer[0];
   if (cinfo->in_color_space == JCS_EXT_BGRX ||
       cinfo->in_color_space == JCS_EXT_BGRA) {
     MEMCOPY(outptr, inptr, source->row_width);
   } else if (cinfo->in_color_space == JCS_CMYK) {
     for (col = cinfo->image_width; col > 0; col--) {
       JSAMPLE b = *inptr++, g = *inptr++, r = *inptr++;
       rgb_to_cmyk(r, g, b, outptr, outptr + 1, outptr + 2, outptr + 3);
       inptr++;                          /* skip the 4th byte (Alpha channel) */
       outptr += 4;
     }
   } else {
     register int rindex = rgb_red[cinfo->in_color_space];
     register int gindex = rgb_green[cinfo->in_color_space];
     register int bindex = rgb_blue[cinfo->in_color_space];
     register int aindex = alpha_index[cinfo->in_color_space];
     register int ps = rgb_pixelsize[cinfo->in_color_space];

     if (aindex >= 0) {
       for (col = cinfo->image_width; col > 0; col--) {
         outptr[bindex] = *inptr++;
         outptr[gindex] = *inptr++;
         outptr[rindex] = *inptr++;
         outptr[aindex] = *inptr++;
         outptr += ps;
       }
     } else {
       for (col = cinfo->image_width; col > 0; col--) {
         outptr[bindex] = *inptr++;
         outptr[gindex] = *inptr++;
         outptr[rindex] = *inptr++;
         inptr++;                        /* skip the 4th byte (Alpha channel) */
         outptr += ps;
       }
     }
   }

   return 1;
 }


 /*
  * This method loads the image into whole_image during the first call on
  * get_pixel_rows.  The get_pixel_rows pointer is then adjusted to call
  * get_8bit_row, get_24bit_row, or get_32bit_row on subsequent calls.
  */

 METHODDEF(JDIMENSION)
 preload_image(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
 {
   bmp_source_ptr source = (bmp_source_ptr)sinfo;
   register FILE *infile = source->pub.input_file;
   register JSAMPROW out_ptr;
   JSAMPARRAY image_ptr;
   JDIMENSION row;
   cd_progress_ptr progress = (cd_progress_ptr)cinfo->progress;

   /* Read the data into a virtual array in input-file row order. */
   for (row = 0; row < cinfo->image_height; row++) {
     if (progress != NULL) {
       progress->pub.pass_counter = (long)row;
       progress->pub.pass_limit = (long)cinfo->image_height;
       (*progress->pub.progress_monitor) ((j_common_ptr)cinfo);
     }
     image_ptr = (*cinfo->mem->access_virt_sarray)
       ((j_common_ptr)cinfo, source->whole_image, row, (JDIMENSION)1, TRUE);
     out_ptr = image_ptr[0];
     if (fread(out_ptr, 1, source->row_width, infile) != source->row_width) {
       if (feof(infile))
         ERREXIT(cinfo, JERR_INPUT_EOF);
       else
         ERREXIT(cinfo, JERR_FILE_READ);
     }
   }
   if (progress != NULL)
     progress->completed_extra_passes++;

   /* Set up to read from the virtual array in top-to-bottom order */
   switch (source->bits_per_pixel) {
   case 8:
     source->pub.get_pixel_rows = get_8bit_row;
     break;
   case 24:
     source->pub.get_pixel_rows = get_24bit_row;
     break;
   case 32:
     source->pub.get_pixel_rows = get_32bit_row;
     break;
   default:
     ERREXIT(cinfo, JERR_BMP_BADDEPTH);
   }
   source->source_row = cinfo->image_height;

   /* And read the first row */
   return (*source->pub.get_pixel_rows) (cinfo, sinfo);
 }


 /*
  * Read the file header; return image size and component count.
  */

 METHODDEF(void)
 start_input_bmp(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
 {
   bmp_source_ptr source = (bmp_source_ptr)sinfo;
   U_CHAR bmpfileheader[14];
   U_CHAR bmpinfoheader[64];

 #define GET_2B(array, offset) \
   ((unsigned short)UCH(array[offset]) + \
    (((unsigned short)UCH(array[offset + 1])) << 8))
 #define GET_4B(array, offset) \
   ((unsigned int)UCH(array[offset]) + \
    (((unsigned int)UCH(array[offset + 1])) << 8) + \
    (((unsigned int)UCH(array[offset + 2])) << 16) + \
    (((unsigned int)UCH(array[offset + 3])) << 24))

   int bfOffBits;
   int headerSize;
   int biWidth;
   int biHeight;
   unsigned short biPlanes;
   unsigned int biCompression;
   int biXPelsPerMeter, biYPelsPerMeter;
   int biClrUsed = 0;
   int mapentrysize = 0;         /* 0 indicates no colormap */
   int bPad;
   JDIMENSION row_width = 0;

   /* Read and verify the bitmap file header */
   if (!ReadOK(source->pub.input_file, bmpfileheader, 14))
     ERREXIT(cinfo, JERR_INPUT_EOF);
   if (GET_2B(bmpfileheader, 0) != 0x4D42) /* 'BM' */
     ERREXIT(cinfo, JERR_BMP_NOT);
   bfOffBits = GET_4B(bmpfileheader, 10);
   /* We ignore the remaining fileheader fields */

   /* The infoheader might be 12 bytes (OS/2 1.x), 40 bytes (Windows),
    * or 64 bytes (OS/2 2.x).  Check the first 4 bytes to find out which.
    */
   if (!ReadOK(source->pub.input_file, bmpinfoheader, 4))
     ERREXIT(cinfo, JERR_INPUT_EOF);
   headerSize = GET_4B(bmpinfoheader, 0);
   if (headerSize < 12 || headerSize > 64 || (headerSize + 14) > bfOffBits)
     ERREXIT(cinfo, JERR_BMP_BADHEADER);
   if (!ReadOK(source->pub.input_file, bmpinfoheader + 4, headerSize - 4))
     ERREXIT(cinfo, JERR_INPUT_EOF);

   switch (headerSize) {
   case 12:
     /* Decode OS/2 1.x header (Microsoft calls this a BITMAPCOREHEADER) */
     biWidth = (int)GET_2B(bmpinfoheader, 4);
     biHeight = (int)GET_2B(bmpinfoheader, 6);
     biPlanes = GET_2B(bmpinfoheader, 8);
     source->bits_per_pixel = (int)GET_2B(bmpinfoheader, 10);

     switch (source->bits_per_pixel) {
     case 8:                     /* colormapped image */
       mapentrysize = 3;         /* OS/2 uses RGBTRIPLE colormap */
       TRACEMS2(cinfo, 1, JTRC_BMP_OS2_MAPPED, biWidth, biHeight);
       break;
     case 24:                    /* RGB image */
     case 32:                    /* RGB image + Alpha channel */
       TRACEMS3(cinfo, 1, JTRC_BMP_OS2, biWidth, biHeight,
                source->bits_per_pixel);
       break;
     default:
       ERREXIT(cinfo, JERR_BMP_BADDEPTH);
       break;
     }
     break;
   case 40:
   case 64:
     /* Decode Windows 3.x header (Microsoft calls this a BITMAPINFOHEADER) */
     /* or OS/2 2.x header, which has additional fields that we ignore */
     biWidth = (int)GET_4B(bmpinfoheader, 4);
     biHeight = (int)GET_4B(bmpinfoheader, 8);
     biPlanes = GET_2B(bmpinfoheader, 12);
     source->bits_per_pixel = (int)GET_2B(bmpinfoheader, 14);
     biCompression = GET_4B(bmpinfoheader, 16);
     biXPelsPerMeter = (int)GET_4B(bmpinfoheader, 24);
     biYPelsPerMeter = (int)GET_4B(bmpinfoheader, 28);
     biClrUsed = GET_4B(bmpinfoheader, 32);
     /* biSizeImage, biClrImportant fields are ignored */

     switch (source->bits_per_pixel) {
     case 8:                     /* colormapped image */
       mapentrysize = 4;         /* Windows uses RGBQUAD colormap */
       TRACEMS2(cinfo, 1, JTRC_BMP_MAPPED, biWidth, biHeight);
       break;
     case 24:                    /* RGB image */
     case 32:                    /* RGB image + Alpha channel */
       TRACEMS3(cinfo, 1, JTRC_BMP, biWidth, biHeight, source->bits_per_pixel);
       break;
     default:
       ERREXIT(cinfo, JERR_BMP_BADDEPTH);
       break;
     }
     if (biCompression != 0)
       ERREXIT(cinfo, JERR_BMP_COMPRESSED);

     if (biXPelsPerMeter > 0 && biYPelsPerMeter > 0) {
       /* Set JFIF density parameters from the BMP data */
       cinfo->X_density = (UINT16)(biXPelsPerMeter / 100); /* 100 cm per meter */
       cinfo->Y_density = (UINT16)(biYPelsPerMeter / 100);
       cinfo->density_unit = 2;  /* dots/cm */
     }
     break;
   default:
     ERREXIT(cinfo, JERR_BMP_BADHEADER);
     return;
   }

   if (biWidth <= 0 || biHeight <= 0)
     ERREXIT(cinfo, JERR_BMP_EMPTY);
 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
   if (sinfo->max_pixels &&
       (unsigned long long)biWidth * biHeight > sinfo->max_pixels)
     ERREXIT(cinfo, JERR_WIDTH_OVERFLOW);
 #endif
   if (biPlanes != 1)
     ERREXIT(cinfo, JERR_BMP_BADPLANES);

   /* Compute distance to bitmap data --- will adjust for colormap below */
   bPad = bfOffBits - (headerSize + 14);

   /* Read the colormap, if any */
   if (mapentrysize > 0) {
     if (biClrUsed <= 0)
       biClrUsed = 256;          /* assume it's 256 */
     else if (biClrUsed > 256)
       ERREXIT(cinfo, JERR_BMP_BADCMAP);
     /* Allocate space to store the colormap */
     source->colormap = (*cinfo->mem->alloc_sarray)
       ((j_common_ptr)cinfo, JPOOL_IMAGE, (JDIMENSION)biClrUsed, (JDIMENSION)3);
     source->cmap_length = (int)biClrUsed;
     /* and read it from the file */
     read_colormap(source, (int)biClrUsed, mapentrysize);
     /* account for size of colormap */
     bPad -= biClrUsed * mapentrysize;
   }

   /* Skip any remaining pad bytes */
   if (bPad < 0)                 /* incorrect bfOffBits value? */
     ERREXIT(cinfo, JERR_BMP_BADHEADER);
   while (--bPad >= 0) {
     (void)read_byte(source);
   }

   /* Compute row width in file, including padding to 4-byte boundary */
   switch (source->bits_per_pixel) {
   case 8:
     if (cinfo->in_color_space == JCS_UNKNOWN)
       cinfo->in_color_space = JCS_EXT_RGB;
     if (IsExtRGB(cinfo->in_color_space))
       cinfo->input_components = rgb_pixelsize[cinfo->in_color_space];
     else if (cinfo->in_color_space == JCS_GRAYSCALE)
       cinfo->input_components = 1;
     else if (cinfo->in_color_space == JCS_CMYK)
       cinfo->input_components = 4;
     else
       ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
     row_width = (JDIMENSION)biWidth;
     break;
   case 24:
     if (cinfo->in_color_space == JCS_UNKNOWN)
       cinfo->in_color_space = JCS_EXT_BGR;
     if (IsExtRGB(cinfo->in_color_space))
       cinfo->input_components = rgb_pixelsize[cinfo->in_color_space];
     else if (cinfo->in_color_space == JCS_CMYK)
       cinfo->input_components = 4;
     else
       ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
     if ((unsigned long long)biWidth * 3ULL > 0xFFFFFFFFULL)
       ERREXIT(cinfo, JERR_WIDTH_OVERFLOW);
     row_width = (JDIMENSION)biWidth * 3;
     break;
   case 32:
     if (cinfo->in_color_space == JCS_UNKNOWN)
       cinfo->in_color_space = JCS_EXT_BGRA;
     if (IsExtRGB(cinfo->in_color_space))
       cinfo->input_components = rgb_pixelsize[cinfo->in_color_space];
     else if (cinfo->in_color_space == JCS_CMYK)
       cinfo->input_components = 4;
     else
       ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
     if ((unsigned long long)biWidth * 4ULL > 0xFFFFFFFFULL)
       ERREXIT(cinfo, JERR_WIDTH_OVERFLOW);
     row_width = (JDIMENSION)biWidth * 4;
     break;
   default:
     ERREXIT(cinfo, JERR_BMP_BADDEPTH);
   }
   while ((row_width & 3) != 0) row_width++;
   source->row_width = row_width;

   if (source->use_inversion_array) {
     /* Allocate space for inversion array, prepare for preload pass */
     source->whole_image = (*cinfo->mem->request_virt_sarray)
       ((j_common_ptr)cinfo, JPOOL_IMAGE, FALSE,
        row_width, (JDIMENSION)biHeight, (JDIMENSION)1);
     source->pub.get_pixel_rows = preload_image;
     if (cinfo->progress != NULL) {
       cd_progress_ptr progress = (cd_progress_ptr)cinfo->progress;
       progress->total_extra_passes++; /* count file input as separate pass */
     }
   } else {
     source->iobuffer = (U_CHAR *)
       (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE, row_width);
     switch (source->bits_per_pixel) {
     case 8:
       source->pub.get_pixel_rows = get_8bit_row;
       break;
     case 24:
       source->pub.get_pixel_rows = get_24bit_row;
       break;
     case 32:
       source->pub.get_pixel_rows = get_32bit_row;
       break;
     default:
       ERREXIT(cinfo, JERR_BMP_BADDEPTH);
     }
   }

   /* Ensure that biWidth * cinfo->input_components doesn't exceed the maximum
      value of the JDIMENSION type.  This is only a danger with BMP files, since
      their width and height fields are 32-bit integers. */
   if ((unsigned long long)biWidth *
       (unsigned long long)cinfo->input_components > 0xFFFFFFFFULL)
     ERREXIT(cinfo, JERR_WIDTH_OVERFLOW);
   /* Allocate one-row buffer for returned data */
   source->pub.buffer = (*cinfo->mem->alloc_sarray)
     ((j_common_ptr)cinfo, JPOOL_IMAGE,
      (JDIMENSION)biWidth * (JDIMENSION)cinfo->input_components, (JDIMENSION)1);
   source->pub.buffer_height = 1;

   cinfo->data_precision = 8;
   cinfo->image_width = (JDIMENSION)biWidth;
   cinfo->image_height = (JDIMENSION)biHeight;
 }


 /*
  * Finish up at the end of the file.
  */

 METHODDEF(void)
 finish_input_bmp(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
 {
   /* no work */
 }


 /*
  * The module selection routine for BMP format input.
  */

 GLOBAL(cjpeg_source_ptr)
 jinit_read_bmp(j_compress_ptr cinfo, boolean use_inversion_array)
 {
   bmp_source_ptr source;

   /* Create module interface object */
   source = (bmp_source_ptr)
     (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
                                 sizeof(bmp_source_struct));
   source->cinfo = cinfo;        /* make back link for subroutines */
   /* Fill in method ptrs, except get_pixel_rows which start_input sets */
   source->pub.start_input = start_input_bmp;
   source->pub.finish_input = finish_input_bmp;
 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
   source->pub.max_pixels = 0;
 #endif

   source->use_inversion_array = use_inversion_array;

   return (cjpeg_source_ptr)source;
 }

 #endif /* BMP_SUPPORTED */
	/*
	* rdbmp.c
	*
	* This file was part of the Independent JPEG Group's software:
	* Copyright (C) 1994-1996, Thomas G. Lane.
	* Modified 2009-2017 by Guido Vollbeding.
	* libjpeg-turbo Modifications:
	* Modified 2011 by Siarhei Siamashka.
	* Copyright (C) 2015, 2017-2018, 2021, D. R. Commander.
	* For conditions of distribution and use, see the accompanying README.ijg
	* file.
	*
	* This file contains routines to read input images in Microsoft "BMP"
	* format (MS Windows 3.x, OS/2 1.x, and OS/2 2.x flavors).
	* Currently, only 8-, 24-, and 32-bit images are supported, not 1-bit or
	* 4-bit (feeding such low-depth images into JPEG would be silly anyway).
	* Also, we don't support RLE-compressed files.
	*
	* These routines may need modification for non-Unix environments or
	* specialized applications. As they stand, they assume input from
	* an ordinary stdio stream. They further assume that reading begins
	* at the start of the file; start_input may need work if the
	* user interface has already read some data (e.g., to determine that
	* the file is indeed BMP format).
	*
	* This code contributed by James Arthur Boucher.
	*/

	#include "cmyk.h"
	#include "cdjpeg.h" /* Common decls for cjpeg/djpeg applications */

	#ifdef BMP_SUPPORTED


	/* Macros to deal with unsigned chars as efficiently as compiler allows */

	typedef unsigned char U_CHAR;
	#define UCH(x) ((int)(x))


	#define ReadOK(file, buffer, len) \
	(JFREAD(file, buffer, len) == ((size_t)(len)))

	static int alpha_index[JPEG_NUMCS] = {
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 3, 3, 0, 0, -1
	};


	/* Private version of data source object */

	typedef struct _bmp_source_struct *bmp_source_ptr;

	typedef struct _bmp_source_struct {
	struct cjpeg_source_struct pub; /* public fields */

	j_compress_ptr cinfo; /* back link saves passing separate parm */

	JSAMPARRAY colormap; /* BMP colormap (converted to my format) */

	jvirt_sarray_ptr whole_image; /* Needed to reverse row order */
	JDIMENSION source_row; /* Current source row number */
	JDIMENSION row_width; /* Physical width of scanlines in file */

	int bits_per_pixel; /* remembers 8-, 24-, or 32-bit format */
	int cmap_length; /* colormap length */

	boolean use_inversion_array; /* TRUE = preload the whole image, which is
	stored in bottom-up order, and feed it to
	the calling program in top-down order

	FALSE = the calling program will maintain
	its own image buffer and read the rows in
	bottom-up order */

	U_CHAR iobuffer; / I/O buffer (used to buffer a single row from
	disk if use_inversion_array == FALSE) */
	} bmp_source_struct;


	LOCAL(int)
	read_byte(bmp_source_ptr sinfo)
	/* Read next byte from BMP file */
	{
	register FILE *infile = sinfo->pub.input_file;
	register int c;

	if ((c = getc(infile)) == EOF)
	ERREXIT(sinfo->cinfo, JERR_INPUT_EOF);
	return c;
	}


	LOCAL(void)
	read_colormap(bmp_source_ptr sinfo, int cmaplen, int mapentrysize)
	/* Read the colormap from a BMP file */
	{
	int i, gray = 1;

	switch (mapentrysize) {
	case 3:
	/* BGR format (occurs in OS/2 files) */
	for (i = 0; i < cmaplen; i++) {
	sinfo->colormap[2][i] = (JSAMPLE)read_byte(sinfo);
	sinfo->colormap[1][i] = (JSAMPLE)read_byte(sinfo);
	sinfo->colormap[0][i] = (JSAMPLE)read_byte(sinfo);
	if (sinfo->colormap[2][i] != sinfo->colormap[1][i] \|\|
	sinfo->colormap[1][i] != sinfo->colormap[0][i])
	gray = 0;
	}
	break;
	case 4:
	/* BGR0 format (occurs in MS Windows files) */
	for (i = 0; i < cmaplen; i++) {
	sinfo->colormap[2][i] = (JSAMPLE)read_byte(sinfo);
	sinfo->colormap[1][i] = (JSAMPLE)read_byte(sinfo);
	sinfo->colormap[0][i] = (JSAMPLE)read_byte(sinfo);
	(void)read_byte(sinfo);
	if (sinfo->colormap[2][i] != sinfo->colormap[1][i] \|\|
	sinfo->colormap[1][i] != sinfo->colormap[0][i])
	gray = 0;
	}
	break;
	default:
	ERREXIT(sinfo->cinfo, JERR_BMP_BADCMAP);
	break;
	}

	if (sinfo->cinfo->in_color_space == JCS_UNKNOWN && gray)
	sinfo->cinfo->in_color_space = JCS_GRAYSCALE;

	if (sinfo->cinfo->in_color_space == JCS_GRAYSCALE && !gray)
	ERREXIT(sinfo->cinfo, JERR_BAD_IN_COLORSPACE);
	}


	/*
	* Read one row of pixels.
	* The image has been read into the whole_image array, but is otherwise
	* unprocessed. We must read it out in top-to-bottom row order, and if
	* it is an 8-bit image, we must expand colormapped pixels to 24bit format.
	*/

	METHODDEF(JDIMENSION)
	get_8bit_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
	/* This version is for reading 8-bit colormap indexes */
	{
	bmp_source_ptr source = (bmp_source_ptr)sinfo;
	register JSAMPARRAY colormap = source->colormap;
	int cmaplen = source->cmap_length;
	JSAMPARRAY image_ptr;
	register int t;
	register JSAMPROW inptr, outptr;
	register JDIMENSION col;

	if (source->use_inversion_array) {
	/* Fetch next row from virtual array */
	source->source_row--;
	image_ptr = (*cinfo->mem->access_virt_sarray)
	((j_common_ptr)cinfo, source->whole_image,
	source->source_row, (JDIMENSION)1, FALSE);
	inptr = image_ptr[0];
	} else {
	if (!ReadOK(source->pub.input_file, source->iobuffer, source->row_width))
	ERREXIT(cinfo, JERR_INPUT_EOF);
	inptr = source->iobuffer;
	}

	/* Expand the colormap indexes to real data */
	outptr = source->pub.buffer[0];
	if (cinfo->in_color_space == JCS_GRAYSCALE) {
	for (col = cinfo->image_width; col > 0; col--) {
	t = *inptr++;
	if (t >= cmaplen)
	ERREXIT(cinfo, JERR_BMP_OUTOFRANGE);
	*outptr++ = colormap[0][t];
	}
	} else if (cinfo->in_color_space == JCS_CMYK) {
	for (col = cinfo->image_width; col > 0; col--) {
	t = *inptr++;
	if (t >= cmaplen)
	ERREXIT(cinfo, JERR_BMP_OUTOFRANGE);
	rgb_to_cmyk(colormap[0][t], colormap[1][t], colormap[2][t], outptr,
	outptr + 1, outptr + 2, outptr + 3);
	outptr += 4;
	}
	} else {
	register int rindex = rgb_red[cinfo->in_color_space];
	register int gindex = rgb_green[cinfo->in_color_space];
	register int bindex = rgb_blue[cinfo->in_color_space];
	register int aindex = alpha_index[cinfo->in_color_space];
	register int ps = rgb_pixelsize[cinfo->in_color_space];

	if (aindex >= 0) {
	for (col = cinfo->image_width; col > 0; col--) {
	t = *inptr++;
	if (t >= cmaplen)
	ERREXIT(cinfo, JERR_BMP_OUTOFRANGE);
	outptr[rindex] = colormap[0][t];
	outptr[gindex] = colormap[1][t];
	outptr[bindex] = colormap[2][t];
	outptr[aindex] = 0xFF;
	outptr += ps;
	}
	} else {
	for (col = cinfo->image_width; col > 0; col--) {
	t = *inptr++;
	if (t >= cmaplen)
	ERREXIT(cinfo, JERR_BMP_OUTOFRANGE);
	outptr[rindex] = colormap[0][t];
	outptr[gindex] = colormap[1][t];
	outptr[bindex] = colormap[2][t];
	outptr += ps;
	}
	}
	}

	return 1;
	}


	METHODDEF(JDIMENSION)
	get_24bit_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
	/* This version is for reading 24-bit pixels */
	{
	bmp_source_ptr source = (bmp_source_ptr)sinfo;
	JSAMPARRAY image_ptr;
	register JSAMPROW inptr, outptr;
	register JDIMENSION col;

	if (source->use_inversion_array) {
	/* Fetch next row from virtual array */
	source->source_row--;
	image_ptr = (*cinfo->mem->access_virt_sarray)
	((j_common_ptr)cinfo, source->whole_image,
	source->source_row, (JDIMENSION)1, FALSE);
	inptr = image_ptr[0];
	} else {
	if (!ReadOK(source->pub.input_file, source->iobuffer, source->row_width))
	ERREXIT(cinfo, JERR_INPUT_EOF);
	inptr = source->iobuffer;
	}

	/* Transfer data. Note source values are in BGR order
	* (even though Microsoft's own documents say the opposite).
	*/
	outptr = source->pub.buffer[0];
	if (cinfo->in_color_space == JCS_EXT_BGR) {
	MEMCOPY(outptr, inptr, source->row_width);
	} else if (cinfo->in_color_space == JCS_CMYK) {
	for (col = cinfo->image_width; col > 0; col--) {
	JSAMPLE b = inptr++, g = inptr++, r = *inptr++;
	rgb_to_cmyk(r, g, b, outptr, outptr + 1, outptr + 2, outptr + 3);
	outptr += 4;
	}
	} else {
	register int rindex = rgb_red[cinfo->in_color_space];
	register int gindex = rgb_green[cinfo->in_color_space];
	register int bindex = rgb_blue[cinfo->in_color_space];
	register int aindex = alpha_index[cinfo->in_color_space];
	register int ps = rgb_pixelsize[cinfo->in_color_space];

	if (aindex >= 0) {
	for (col = cinfo->image_width; col > 0; col--) {
	outptr[bindex] = *inptr++;
	outptr[gindex] = *inptr++;
	outptr[rindex] = *inptr++;
	outptr[aindex] = 0xFF;
	outptr += ps;
	}
	} else {
	for (col = cinfo->image_width; col > 0; col--) {
	outptr[bindex] = *inptr++;
	outptr[gindex] = *inptr++;
	outptr[rindex] = *inptr++;
	outptr += ps;
	}
	}
	}

	return 1;
	}


	METHODDEF(JDIMENSION)
	get_32bit_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
	/* This version is for reading 32-bit pixels */
	{
	bmp_source_ptr source = (bmp_source_ptr)sinfo;
	JSAMPARRAY image_ptr;
	register JSAMPROW inptr, outptr;
	register JDIMENSION col;

	if (source->use_inversion_array) {
	/* Fetch next row from virtual array */
	source->source_row--;
	image_ptr = (*cinfo->mem->access_virt_sarray)
	((j_common_ptr)cinfo, source->whole_image,
	source->source_row, (JDIMENSION)1, FALSE);
	inptr = image_ptr[0];
	} else {
	if (!ReadOK(source->pub.input_file, source->iobuffer, source->row_width))
	ERREXIT(cinfo, JERR_INPUT_EOF);
	inptr = source->iobuffer;
	}

	/* Transfer data. Note source values are in BGR order
	* (even though Microsoft's own documents say the opposite).
	*/
	outptr = source->pub.buffer[0];
	if (cinfo->in_color_space == JCS_EXT_BGRX \|\|
	cinfo->in_color_space == JCS_EXT_BGRA) {
	MEMCOPY(outptr, inptr, source->row_width);
	} else if (cinfo->in_color_space == JCS_CMYK) {
	for (col = cinfo->image_width; col > 0; col--) {
	JSAMPLE b = inptr++, g = inptr++, r = *inptr++;
	rgb_to_cmyk(r, g, b, outptr, outptr + 1, outptr + 2, outptr + 3);
	inptr++; /* skip the 4th byte (Alpha channel) */
	outptr += 4;
	}
	} else {
	register int rindex = rgb_red[cinfo->in_color_space];
	register int gindex = rgb_green[cinfo->in_color_space];
	register int bindex = rgb_blue[cinfo->in_color_space];
	register int aindex = alpha_index[cinfo->in_color_space];
	register int ps = rgb_pixelsize[cinfo->in_color_space];

	if (aindex >= 0) {
	for (col = cinfo->image_width; col > 0; col--) {
	outptr[bindex] = *inptr++;
	outptr[gindex] = *inptr++;
	outptr[rindex] = *inptr++;
	outptr[aindex] = *inptr++;
	outptr += ps;
	}
	} else {
	for (col = cinfo->image_width; col > 0; col--) {
	outptr[bindex] = *inptr++;
	outptr[gindex] = *inptr++;
	outptr[rindex] = *inptr++;
	inptr++; /* skip the 4th byte (Alpha channel) */
	outptr += ps;
	}
	}
	}

	return 1;
	}


	/*
	* This method loads the image into whole_image during the first call on
	* get_pixel_rows. The get_pixel_rows pointer is then adjusted to call
	* get_8bit_row, get_24bit_row, or get_32bit_row on subsequent calls.
	*/

	METHODDEF(JDIMENSION)
	preload_image(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
	{
	bmp_source_ptr source = (bmp_source_ptr)sinfo;
	register FILE *infile = source->pub.input_file;
	register JSAMPROW out_ptr;
	JSAMPARRAY image_ptr;
	JDIMENSION row;
	cd_progress_ptr progress = (cd_progress_ptr)cinfo->progress;

	/* Read the data into a virtual array in input-file row order. */
	for (row = 0; row < cinfo->image_height; row++) {
	if (progress != NULL) {
	progress->pub.pass_counter = (long)row;
	progress->pub.pass_limit = (long)cinfo->image_height;
	(*progress->pub.progress_monitor) ((j_common_ptr)cinfo);
	}
	image_ptr = (*cinfo->mem->access_virt_sarray)
	((j_common_ptr)cinfo, source->whole_image, row, (JDIMENSION)1, TRUE);
	out_ptr = image_ptr[0];
	if (fread(out_ptr, 1, source->row_width, infile) != source->row_width) {
	if (feof(infile))
	ERREXIT(cinfo, JERR_INPUT_EOF);
	else
	ERREXIT(cinfo, JERR_FILE_READ);
	}
	}
	if (progress != NULL)
	progress->completed_extra_passes++;

	/* Set up to read from the virtual array in top-to-bottom order */
	switch (source->bits_per_pixel) {
	case 8:
	source->pub.get_pixel_rows = get_8bit_row;
	break;
	case 24:
	source->pub.get_pixel_rows = get_24bit_row;
	break;
	case 32:
	source->pub.get_pixel_rows = get_32bit_row;
	break;
	default:
	ERREXIT(cinfo, JERR_BMP_BADDEPTH);
	}
	source->source_row = cinfo->image_height;

	/* And read the first row */
	return (*source->pub.get_pixel_rows) (cinfo, sinfo);
	}


	/*
	* Read the file header; return image size and component count.
	*/

	METHODDEF(void)
	start_input_bmp(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
	{
	bmp_source_ptr source = (bmp_source_ptr)sinfo;
	U_CHAR bmpfileheader[14];
	U_CHAR bmpinfoheader[64];

	#define GET_2B(array, offset) \
	((unsigned short)UCH(array[offset]) + \
	(((unsigned short)UCH(array[offset + 1])) << 8))
	#define GET_4B(array, offset) \
	((unsigned int)UCH(array[offset]) + \
	(((unsigned int)UCH(array[offset + 1])) << 8) + \
	(((unsigned int)UCH(array[offset + 2])) << 16) + \
	(((unsigned int)UCH(array[offset + 3])) << 24))

	int bfOffBits;
	int headerSize;
	int biWidth;
	int biHeight;
	unsigned short biPlanes;
	unsigned int biCompression;
	int biXPelsPerMeter, biYPelsPerMeter;
	int biClrUsed = 0;
	int mapentrysize = 0; /* 0 indicates no colormap */
	int bPad;
	JDIMENSION row_width = 0;

	/* Read and verify the bitmap file header */
	if (!ReadOK(source->pub.input_file, bmpfileheader, 14))
	ERREXIT(cinfo, JERR_INPUT_EOF);
	if (GET_2B(bmpfileheader, 0) != 0x4D42) /* 'BM' */
	ERREXIT(cinfo, JERR_BMP_NOT);
	bfOffBits = GET_4B(bmpfileheader, 10);
	/* We ignore the remaining fileheader fields */

	/* The infoheader might be 12 bytes (OS/2 1.x), 40 bytes (Windows),
	* or 64 bytes (OS/2 2.x). Check the first 4 bytes to find out which.
	*/
	if (!ReadOK(source->pub.input_file, bmpinfoheader, 4))
	ERREXIT(cinfo, JERR_INPUT_EOF);
	headerSize = GET_4B(bmpinfoheader, 0);
	if (headerSize < 12 \|\| headerSize > 64 \|\| (headerSize + 14) > bfOffBits)
	ERREXIT(cinfo, JERR_BMP_BADHEADER);
	if (!ReadOK(source->pub.input_file, bmpinfoheader + 4, headerSize - 4))
	ERREXIT(cinfo, JERR_INPUT_EOF);

	switch (headerSize) {
	case 12:
	/* Decode OS/2 1.x header (Microsoft calls this a BITMAPCOREHEADER) */
	biWidth = (int)GET_2B(bmpinfoheader, 4);
	biHeight = (int)GET_2B(bmpinfoheader, 6);
	biPlanes = GET_2B(bmpinfoheader, 8);
	source->bits_per_pixel = (int)GET_2B(bmpinfoheader, 10);

	switch (source->bits_per_pixel) {
	case 8: /* colormapped image */
	mapentrysize = 3; /* OS/2 uses RGBTRIPLE colormap */
	TRACEMS2(cinfo, 1, JTRC_BMP_OS2_MAPPED, biWidth, biHeight);
	break;
	case 24: /* RGB image */
	case 32: /* RGB image + Alpha channel */
	TRACEMS3(cinfo, 1, JTRC_BMP_OS2, biWidth, biHeight,
	source->bits_per_pixel);
	break;
	default:
	ERREXIT(cinfo, JERR_BMP_BADDEPTH);
	break;
	}
	break;
	case 40:
	case 64:
	/* Decode Windows 3.x header (Microsoft calls this a BITMAPINFOHEADER) */
	/* or OS/2 2.x header, which has additional fields that we ignore */
	biWidth = (int)GET_4B(bmpinfoheader, 4);
	biHeight = (int)GET_4B(bmpinfoheader, 8);
	biPlanes = GET_2B(bmpinfoheader, 12);
	source->bits_per_pixel = (int)GET_2B(bmpinfoheader, 14);
	biCompression = GET_4B(bmpinfoheader, 16);
	biXPelsPerMeter = (int)GET_4B(bmpinfoheader, 24);
	biYPelsPerMeter = (int)GET_4B(bmpinfoheader, 28);
	biClrUsed = GET_4B(bmpinfoheader, 32);
	/* biSizeImage, biClrImportant fields are ignored */

	switch (source->bits_per_pixel) {
	case 8: /* colormapped image */
	mapentrysize = 4; /* Windows uses RGBQUAD colormap */
	TRACEMS2(cinfo, 1, JTRC_BMP_MAPPED, biWidth, biHeight);
	break;
	case 24: /* RGB image */
	case 32: /* RGB image + Alpha channel */
	TRACEMS3(cinfo, 1, JTRC_BMP, biWidth, biHeight, source->bits_per_pixel);
	break;
	default:
	ERREXIT(cinfo, JERR_BMP_BADDEPTH);
	break;
	}
	if (biCompression != 0)
	ERREXIT(cinfo, JERR_BMP_COMPRESSED);

	if (biXPelsPerMeter > 0 && biYPelsPerMeter > 0) {
	/* Set JFIF density parameters from the BMP data */
	cinfo->X_density = (UINT16)(biXPelsPerMeter / 100); /* 100 cm per meter */
	cinfo->Y_density = (UINT16)(biYPelsPerMeter / 100);
	cinfo->density_unit = 2; /* dots/cm */
	}
	break;
	default:
	ERREXIT(cinfo, JERR_BMP_BADHEADER);
	return;
	}

	if (biWidth <= 0 \|\| biHeight <= 0)
	ERREXIT(cinfo, JERR_BMP_EMPTY);
	#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
	if (sinfo->max_pixels &&
	(unsigned long long)biWidth * biHeight > sinfo->max_pixels)
	ERREXIT(cinfo, JERR_WIDTH_OVERFLOW);
	#endif
	if (biPlanes != 1)
	ERREXIT(cinfo, JERR_BMP_BADPLANES);

	/* Compute distance to bitmap data --- will adjust for colormap below */
	bPad = bfOffBits - (headerSize + 14);

	/* Read the colormap, if any */
	if (mapentrysize > 0) {
	if (biClrUsed <= 0)
	biClrUsed = 256; /* assume it's 256 */
	else if (biClrUsed > 256)
	ERREXIT(cinfo, JERR_BMP_BADCMAP);
	/* Allocate space to store the colormap */
	source->colormap = (*cinfo->mem->alloc_sarray)
	((j_common_ptr)cinfo, JPOOL_IMAGE, (JDIMENSION)biClrUsed, (JDIMENSION)3);
	source->cmap_length = (int)biClrUsed;
	/* and read it from the file */
	read_colormap(source, (int)biClrUsed, mapentrysize);
	/* account for size of colormap */
	bPad -= biClrUsed * mapentrysize;
	}

	/* Skip any remaining pad bytes */
	if (bPad < 0) /* incorrect bfOffBits value? */
	ERREXIT(cinfo, JERR_BMP_BADHEADER);
	while (--bPad >= 0) {
	(void)read_byte(source);
	}

	/* Compute row width in file, including padding to 4-byte boundary */
	switch (source->bits_per_pixel) {
	case 8:
	if (cinfo->in_color_space == JCS_UNKNOWN)
	cinfo->in_color_space = JCS_EXT_RGB;
	if (IsExtRGB(cinfo->in_color_space))
	cinfo->input_components = rgb_pixelsize[cinfo->in_color_space];
	else if (cinfo->in_color_space == JCS_GRAYSCALE)
	cinfo->input_components = 1;
	else if (cinfo->in_color_space == JCS_CMYK)
	cinfo->input_components = 4;
	else
	ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
	row_width = (JDIMENSION)biWidth;
	break;
	case 24:
	if (cinfo->in_color_space == JCS_UNKNOWN)
	cinfo->in_color_space = JCS_EXT_BGR;
	if (IsExtRGB(cinfo->in_color_space))
	cinfo->input_components = rgb_pixelsize[cinfo->in_color_space];
	else if (cinfo->in_color_space == JCS_CMYK)
	cinfo->input_components = 4;
	else
	ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
	if ((unsigned long long)biWidth * 3ULL > 0xFFFFFFFFULL)
	ERREXIT(cinfo, JERR_WIDTH_OVERFLOW);
	row_width = (JDIMENSION)biWidth * 3;
	break;
	case 32:
	if (cinfo->in_color_space == JCS_UNKNOWN)
	cinfo->in_color_space = JCS_EXT_BGRA;
	if (IsExtRGB(cinfo->in_color_space))
	cinfo->input_components = rgb_pixelsize[cinfo->in_color_space];
	else if (cinfo->in_color_space == JCS_CMYK)
	cinfo->input_components = 4;
	else
	ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
	if ((unsigned long long)biWidth * 4ULL > 0xFFFFFFFFULL)
	ERREXIT(cinfo, JERR_WIDTH_OVERFLOW);
	row_width = (JDIMENSION)biWidth * 4;
	break;
	default:
	ERREXIT(cinfo, JERR_BMP_BADDEPTH);
	}
	while ((row_width & 3) != 0) row_width++;
	source->row_width = row_width;

	if (source->use_inversion_array) {
	/* Allocate space for inversion array, prepare for preload pass */
	source->whole_image = (*cinfo->mem->request_virt_sarray)
	((j_common_ptr)cinfo, JPOOL_IMAGE, FALSE,
	row_width, (JDIMENSION)biHeight, (JDIMENSION)1);
	source->pub.get_pixel_rows = preload_image;
	if (cinfo->progress != NULL) {
	cd_progress_ptr progress = (cd_progress_ptr)cinfo->progress;
	progress->total_extra_passes++; /* count file input as separate pass */
	}
	} else {
	source->iobuffer = (U_CHAR *)
	(*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE, row_width);
	switch (source->bits_per_pixel) {
	case 8:
	source->pub.get_pixel_rows = get_8bit_row;
	break;
	case 24:
	source->pub.get_pixel_rows = get_24bit_row;
	break;
	case 32:
	source->pub.get_pixel_rows = get_32bit_row;
	break;
	default:
	ERREXIT(cinfo, JERR_BMP_BADDEPTH);
	}
	}

	/* Ensure that biWidth * cinfo->input_components doesn't exceed the maximum
	value of the JDIMENSION type. This is only a danger with BMP files, since
	their width and height fields are 32-bit integers. */
	if ((unsigned long long)biWidth *
	(unsigned long long)cinfo->input_components > 0xFFFFFFFFULL)
	ERREXIT(cinfo, JERR_WIDTH_OVERFLOW);
	/* Allocate one-row buffer for returned data */
	source->pub.buffer = (*cinfo->mem->alloc_sarray)
	((j_common_ptr)cinfo, JPOOL_IMAGE,
	(JDIMENSION)biWidth * (JDIMENSION)cinfo->input_components, (JDIMENSION)1);
	source->pub.buffer_height = 1;

	cinfo->data_precision = 8;
	cinfo->image_width = (JDIMENSION)biWidth;
	cinfo->image_height = (JDIMENSION)biHeight;
	}


	/*
	* Finish up at the end of the file.
	*/

	METHODDEF(void)
	finish_input_bmp(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
	{
	/* no work */
	}


	/*
	* The module selection routine for BMP format input.
	*/

	GLOBAL(cjpeg_source_ptr)
	jinit_read_bmp(j_compress_ptr cinfo, boolean use_inversion_array)
	{
	bmp_source_ptr source;

	/* Create module interface object */
	source = (bmp_source_ptr)
	(*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
	sizeof(bmp_source_struct));
	source->cinfo = cinfo; /* make back link for subroutines */
	/* Fill in method ptrs, except get_pixel_rows which start_input sets */
	source->pub.start_input = start_input_bmp;
	source->pub.finish_input = finish_input_bmp;
	#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
	source->pub.max_pixels = 0;
	#endif

	source->use_inversion_array = use_inversion_array;

	return (cjpeg_source_ptr)source;
	}

	#endif /* BMP_SUPPORTED */