/*

* rdbmp.c

*

* Copyright (C) 1994-1996, Thomas G. Lane.

* Modified 2009-2019 by Guido Vollbeding.

* This file is part of the Independent JPEG Group's software.

* For conditions of distribution and use, see the accompanying README 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 "cdjpeg.h" /* Common decls for cjpeg/djpeg applications */

#ifdef BMP_SUPPORTED

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

#ifdef HAVE_UNSIGNED_CHAR

typedef unsigned char U_CHAR;

#define UCH(x) ((int) (x))

#else /* !HAVE_UNSIGNED_CHAR */

typedef char U_CHAR;

#ifdef CHAR_IS_UNSIGNED

#define UCH(x) ((int) (x))

#else

#define UCH(x) ((int) (x) & 0xFF)

#endif

#endif /* HAVE_UNSIGNED_CHAR */

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

/* Private version of data source object */

typedef struct _bmp_source_struct * bmp_source_ptr;

typedef struct _bmp_source_struct {

} 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;

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);

}

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);

}

break;

default:

ERREXIT(sinfo->cinfo, JERR_BMP_BADCMAP);

}

}

/*

* 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 JSAMPROW inptr, outptr;

register JSAMPARRAY colormap;

register JDIMENSION col;

register int t;

int cmaplen;

/* Fetch next row from virtual array */

source->source_row--;

inptr = * (*cinfo->mem->access_virt_sarray) ((j_common_ptr) cinfo,

source->whole_image, source->source_row, (JDIMENSION) 1, FALSE);

/* Expand the colormap indexes to real data */

outptr = source->pub.buffer[0];

colormap = source->colormap;

cmaplen = source->cmap_length;

for (col = cinfo->image_width; col > 0; col--) {

t = GETJSAMPLE(*inptr++);

if (t >= cmaplen)

ERREXIT(cinfo, JERR_BMP_OUTOFRANGE);

*outptr++ = colormap[0][t]; /* can omit GETJSAMPLE() safely */

*outptr++ = colormap[1][t];

*outptr++ = colormap[2][t];

}

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;

register JSAMPROW inptr, outptr;

register JDIMENSION col;

/* Fetch next row from virtual array */

source->source_row--;

inptr = * (*cinfo->mem->access_virt_sarray) ((j_common_ptr) cinfo,

source->whole_image, source->source_row, (JDIMENSION) 1, FALSE);

/* Transfer data. Note source values are in BGR order

* (even though Microsoft's own documents say the opposite).

*/

outptr = source->pub.buffer[0];

for (col = cinfo->image_width; col > 0; col--) {

outptr[2] = *inptr++; /* can omit GETJSAMPLE() safely */

outptr[1] = *inptr++;

outptr[0] = *inptr++;

outptr += 3;

}

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;

register JSAMPROW inptr, outptr;

register JDIMENSION col;

/* Fetch next row from virtual array */

source->source_row--;

inptr = * (*cinfo->mem->access_virt_sarray) ((j_common_ptr) cinfo,

source->whole_image, source->source_row, (JDIMENSION) 1, FALSE);

/* Transfer data. Note source values are in BGR order

* (even though Microsoft's own documents say the opposite).

*/

outptr = source->pub.buffer[0];

for (col = cinfo->image_width; col > 0; col--) {

outptr[2] = *inptr++; /* can omit GETJSAMPLE() safely */

outptr[1] = *inptr++;

outptr[0] = *inptr++;

inptr++; /* skip the 4th byte (Alpha channel) */

outptr += 3;

}

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 int c;

register JSAMPROW out_ptr;

JDIMENSION row, col;

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);

}

out_ptr = * (*cinfo->mem->access_virt_sarray) ((j_common_ptr) cinfo,

source->whole_image, row, (JDIMENSION) 1, TRUE);

for (col = source->row_width; col > 0; col--) {

/* inline copy of read_byte() for speed */

if ((c = getc(infile)) == EOF)

ERREXIT(cinfo, JERR_INPUT_EOF);

*out_ptr++ = (JSAMPLE) c;

}

}

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 int) UCH(array[offset]) + \

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

#define GET_4B(array, offset) ((INT32) UCH(array[offset]) + \

(((INT32) UCH(array[offset+1])) << 8) + \

(((INT32) UCH(array[offset+2])) << 16) + \

(((INT32) UCH(array[offset+3])) << 24))

INT32 bfOffBits;

INT32 headerSize;

INT32 biWidth;

INT32 biHeight;

unsigned int biPlanes;

INT32 biCompression;

INT32 biXPelsPerMeter,biYPelsPerMeter;

INT32 biClrUsed = 0;

int mapentrysize = 0; /* 0 indicates no colormap */

INT32 bPad;

JDIMENSION row_width;

/* 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)

ERREXIT(cinfo, JERR_BMP_BADHEADER);

if (! ReadOK(source->pub.input_file, bmpinfoheader + 4, headerSize - 4))

ERREXIT(cinfo, JERR_INPUT_EOF);

switch ((int) headerSize) {

case 12:

/* Decode OS/2 1.x header (Microsoft calls this a BITMAPCOREHEADER) */

biWidth = (INT32) GET_2B(bmpinfoheader, 4);

biHeight = (INT32) 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, (int) biWidth, (int) biHeight);

break;

case 24: /* RGB image */

case 32: /* RGB image + Alpha channel */

TRACEMS3(cinfo, 1, JTRC_BMP_OS2, (int) biWidth, (int) biHeight,

source->bits_per_pixel);

break;

default:

ERREXIT(cinfo, JERR_BMP_BADDEPTH);

}

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 = GET_4B(bmpinfoheader, 4);

biHeight = GET_4B(bmpinfoheader, 8);

biPlanes = GET_2B(bmpinfoheader, 12);

source->bits_per_pixel = (int) GET_2B(bmpinfoheader, 14);

biCompression = GET_4B(bmpinfoheader, 16);

biXPelsPerMeter = GET_4B(bmpinfoheader, 24);

biYPelsPerMeter = 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, (int) biWidth, (int) biHeight);

break;

case 24: /* RGB image */

case 32: /* RGB image + Alpha channel */

TRACEMS3(cinfo, 1, JTRC_BMP, (int) biWidth, (int) biHeight,

source->bits_per_pixel);

break;

default:

ERREXIT(cinfo, JERR_BMP_BADDEPTH);

}

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; /* avoid compiler warnings for uninitialized variables */

}

if (biPlanes != 1)

ERREXIT(cinfo, JERR_BMP_BADPLANES);

/* Sanity check for buffer allocation below */

if (biWidth <= 0 || biHeight <= 0 || (biWidth >> 24) || (biHeight >> 24))

ERREXIT(cinfo, JERR_BMP_OUTOFRANGE);

/* 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 */

if (source->bits_per_pixel == 24)

row_width = (JDIMENSION) (biWidth * 3);

else if (source->bits_per_pixel == 32)

row_width = (JDIMENSION) (biWidth * 4);

else

row_width = (JDIMENSION) biWidth;

while ((row_width & 3) != 0) row_width++;

source->row_width = row_width;

/* 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 */

}

/* Allocate one-row buffer for returned data */

source->pub.buffer = (*cinfo->mem->alloc_sarray) ((j_common_ptr) cinfo,

JPOOL_IMAGE, (JDIMENSION) (biWidth * 3), (JDIMENSION) 1);

source->pub.buffer_height = 1;

cinfo->in_color_space = JCS_RGB;

cinfo->input_components = 3;

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)

{

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;

return &source->pub;

}

#endif /* BMP_SUPPORTED */