0,0 → 1,439 |
/* |
* rdbmp.c |
* |
* Copyright (C) 1994-1996, Thomas G. Lane. |
* 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-bit and 24-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. |
*/ |
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#include "cdjpeg.h" /* Common decls for cjpeg/djpeg applications */ |
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#ifdef BMP_SUPPORTED |
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/* Macros to deal with unsigned chars as efficiently as compiler allows */ |
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#ifdef HAVE_UNSIGNED_CHAR |
typedef unsigned char U_CHAR; |
#define UCH(x) ((int) (x)) |
#else /* !HAVE_UNSIGNED_CHAR */ |
#ifdef CHAR_IS_UNSIGNED |
typedef char U_CHAR; |
#define UCH(x) ((int) (x)) |
#else |
typedef char U_CHAR; |
#define UCH(x) ((int) (x) & 0xFF) |
#endif |
#endif /* HAVE_UNSIGNED_CHAR */ |
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#define ReadOK(file,buffer,len) (JFREAD(file,buffer,len) == ((size_t) (len))) |
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/* Private version of data source object */ |
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typedef struct _bmp_source_struct * bmp_source_ptr; |
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typedef struct _bmp_source_struct { |
struct cjpeg_source_struct pub; /* public fields */ |
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j_compress_ptr cinfo; /* back link saves passing separate parm */ |
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JSAMPARRAY colormap; /* BMP colormap (converted to my format) */ |
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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 */ |
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int bits_per_pixel; /* remembers 8- or 24-bit format */ |
} bmp_source_struct; |
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LOCAL(int) |
read_byte (bmp_source_ptr sinfo) |
/* Read next byte from BMP file */ |
{ |
register FILE *infile = sinfo->pub.input_file; |
register int c; |
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if ((c = getc(infile)) == EOF) |
ERREXIT(sinfo->cinfo, JERR_INPUT_EOF); |
return c; |
} |
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LOCAL(void) |
read_colormap (bmp_source_ptr sinfo, int cmaplen, int mapentrysize) |
/* Read the colormap from a BMP file */ |
{ |
int i; |
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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); |
break; |
} |
} |
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/* |
* 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. |
*/ |
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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; |
JSAMPARRAY image_ptr; |
register int t; |
register JSAMPROW inptr, outptr; |
register JDIMENSION col; |
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/* 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); |
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/* Expand the colormap indexes to real data */ |
inptr = image_ptr[0]; |
outptr = source->pub.buffer[0]; |
for (col = cinfo->image_width; col > 0; col--) { |
t = GETJSAMPLE(*inptr++); |
*outptr++ = colormap[0][t]; /* can omit GETJSAMPLE() safely */ |
*outptr++ = colormap[1][t]; |
*outptr++ = colormap[2][t]; |
} |
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return 1; |
} |
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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; |
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/* 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); |
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/* Transfer data. Note source values are in BGR order |
* (even though Microsoft's own documents say the opposite). |
*/ |
inptr = image_ptr[0]; |
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; |
} |
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return 1; |
} |
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/* |
* 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 or get_24bit_row on subsequent calls. |
*/ |
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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; |
JSAMPARRAY image_ptr; |
JDIMENSION row, col; |
cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress; |
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/* 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]; |
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++; |
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/* 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; |
default: |
ERREXIT(cinfo, JERR_BMP_BADDEPTH); |
} |
source->source_row = cinfo->image_height; |
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/* And read the first row */ |
return (*source->pub.get_pixel_rows) (cinfo, sinfo); |
} |
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/* |
* Read the file header; return image size and component count. |
*/ |
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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 = 0; /* initialize to avoid compiler warning */ |
INT32 biHeight = 0; |
unsigned int biPlanes; |
INT32 biCompression; |
INT32 biXPelsPerMeter,biYPelsPerMeter; |
INT32 biClrUsed = 0; |
int mapentrysize = 0; /* 0 indicates no colormap */ |
INT32 bPad; |
JDIMENSION row_width; |
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/* 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 = (INT32) GET_4B(bmpfileheader,10); |
/* We ignore the remaining fileheader fields */ |
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/* 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 = (INT32) 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); |
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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); |
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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 */ |
TRACEMS2(cinfo, 1, JTRC_BMP_OS2, (int) biWidth, (int) biHeight); |
break; |
default: |
ERREXIT(cinfo, JERR_BMP_BADDEPTH); |
break; |
} |
if (biPlanes != 1) |
ERREXIT(cinfo, JERR_BMP_BADPLANES); |
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 */ |
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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 */ |
TRACEMS2(cinfo, 1, JTRC_BMP, (int) biWidth, (int) biHeight); |
break; |
default: |
ERREXIT(cinfo, JERR_BMP_BADDEPTH); |
break; |
} |
if (biPlanes != 1) |
ERREXIT(cinfo, JERR_BMP_BADPLANES); |
if (biCompression != 0) |
ERREXIT(cinfo, JERR_BMP_COMPRESSED); |
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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); |
break; |
} |
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/* Compute distance to bitmap data --- will adjust for colormap below */ |
bPad = bfOffBits - (headerSize + 14); |
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/* 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); |
/* and read it from the file */ |
read_colormap(source, (int) biClrUsed, mapentrysize); |
/* account for size of colormap */ |
bPad -= biClrUsed * mapentrysize; |
} |
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/* Skip any remaining pad bytes */ |
if (bPad < 0) /* incorrect bfOffBits value? */ |
ERREXIT(cinfo, JERR_BMP_BADHEADER); |
while (--bPad >= 0) { |
(void) read_byte(source); |
} |
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/* Compute row width in file, including padding to 4-byte boundary */ |
if (source->bits_per_pixel == 24) |
row_width = (JDIMENSION) (biWidth * 3); |
else |
row_width = (JDIMENSION) biWidth; |
while ((row_width & 3) != 0) row_width++; |
source->row_width = row_width; |
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/* 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 */ |
} |
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/* 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; |
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cinfo->in_color_space = JCS_RGB; |
cinfo->input_components = 3; |
cinfo->data_precision = 8; |
cinfo->image_width = (JDIMENSION) biWidth; |
cinfo->image_height = (JDIMENSION) biHeight; |
} |
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/* |
* Finish up at the end of the file. |
*/ |
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METHODDEF(void) |
finish_input_bmp (j_compress_ptr cinfo, cjpeg_source_ptr sinfo) |
{ |
/* no work */ |
} |
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/* |
* The module selection routine for BMP format input. |
*/ |
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GLOBAL(cjpeg_source_ptr) |
jinit_read_bmp (j_compress_ptr cinfo) |
{ |
bmp_source_ptr source; |
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/* 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; |
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return (cjpeg_source_ptr) source; |
} |
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#endif /* BMP_SUPPORTED */ |