/*

 * 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, 2021-2023, 2026, 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

#define ReadOK(file, buffer, len) \

  (fread(buffer, 1, len, file) == ((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 */

  unsigned 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 ||

       sinfo->cinfo->in_color_space == JCS_RGB) && 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) {

    memcpy(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) {

    memcpy(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;

  unsigned char bmpfileheader[14];

  unsigned char bmpinfoheader[64];

#define GET_2B(array, offset) \

  ((unsigned short)array[offset] + \

   (((unsigned short)array[offset + 1]) << 8))

#define GET_4B(array, offset) \

  ((unsigned int)array[offset] + \

   (((unsigned int)array[offset + 1]) << 8) + \

   (((unsigned int)array[offset + 2]) << 16) + \

   (((unsigned int)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);

  if (biWidth > JPEG_MAX_DIMENSION || biHeight > JPEG_MAX_DIMENSION)

    ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, JPEG_MAX_DIMENSION);

  if (sinfo->max_pixels &&

      (unsigned long long)biWidth * biHeight > sinfo->max_pixels)

    ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, sinfo->max_pixels);

  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);

    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);

    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 = (unsigned 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);

    }

  }

  /* 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;

  if (cinfo->data_precision != 8)

    ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision);

  /* 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;

  source->pub.max_pixels = 0;

  source->use_inversion_array = use_inversion_array;

  return (cjpeg_source_ptr)source;

}

#endif /* BMP_SUPPORTED */