-#include "image.h"
#include <stdarg.h>
+#include "imageri.h"
-/* possibly this belongs in a global utilities library
- Reads from the specified "file" the specified sizes.
- The format codes match those used by perl's pack() function,
- though only a few are implemented.
- In all cases the vararg arguement is an int *.
+/*
+=head1 NAME
- Returns non-zero if all of the arguments were read.
+bmp.c - read and write windows BMP files
+
+=head1 SYNOPSIS
+
+ i_img *im;
+ io_glue *ig;
+
+ if (!i_writebmp_wiol(im, ig)) {
+ ... error ...
+ }
+ im = i_readbmp(ig);
+
+=head1 DESCRIPTION
+
+Reads and writes Windows BMP files.
+
+=over
+
+=cut
+*/
+
+#define FILEHEAD_SIZE 14
+#define INFOHEAD_SIZE 40
+#define BI_RGB 0
+#define BI_RLE8 1
+#define BI_RLE4 2
+#define BI_BITFIELDS 3
+#define BMPRLE_ENDOFLINE 0
+#define BMPRLE_ENDOFBMP 1
+#define BMPRLE_DELTA 2
+
+static int read_packed(io_glue *ig, char *format, ...);
+static int write_packed(io_glue *ig, char *format, ...);
+static int write_bmphead(io_glue *ig, i_img *im, int bit_count,
+ int data_size);
+static int write_1bit_data(io_glue *ig, i_img *im);
+static int write_4bit_data(io_glue *ig, i_img *im);
+static int write_8bit_data(io_glue *ig, i_img *im);
+static int write_24bit_data(io_glue *ig, i_img *im);
+static int read_bmp_pal(io_glue *ig, i_img *im, int count);
+static i_img *read_1bit_bmp(io_glue *ig, int xsize, int ysize, int clr_used,
+ int compression, long offbits);
+static i_img *read_4bit_bmp(io_glue *ig, int xsize, int ysize, int clr_used,
+ int compression, long offbits);
+static i_img *read_8bit_bmp(io_glue *ig, int xsize, int ysize, int clr_used,
+ int compression, long offbits);
+static i_img *read_direct_bmp(io_glue *ig, int xsize, int ysize,
+ int bit_count, int clr_used, int compression,
+ long offbits);
+
+/*
+=item i_writebmp_wiol(im, io_glue)
+
+Writes the image as a BMP file. Uses 1-bit, 4-bit, 8-bit or 24-bit
+formats depending on the image.
+
+Never compresses the image.
+
+=cut
+*/
+int
+i_writebmp_wiol(i_img *im, io_glue *ig) {
+ io_glue_commit_types(ig);
+ i_clear_error();
+
+ /* pick a format */
+ if (im->type == i_direct_type) {
+ return write_24bit_data(ig, im);
+ }
+ else {
+ int pal_size;
+
+ /* must be paletted */
+ pal_size = i_colorcount(im);
+ if (pal_size <= 2) {
+ return write_1bit_data(ig, im);
+ }
+ else if (pal_size <= 16) {
+ return write_4bit_data(ig, im);
+ }
+ else {
+ return write_8bit_data(ig, im);
+ }
+ }
+}
+
+/*
+=item i_readbmp_wiol(ig)
+
+Reads a Windows format bitmap from the given file.
+
+Handles BI_RLE4 and BI_RLE8 compressed images. Attempts to handle
+BI_BITFIELDS images too, but I need a test image.
+
+=cut
+*/
+
+i_img *
+i_readbmp_wiol(io_glue *ig) {
+ int b_magic, m_magic, filesize, res1, res2, infohead_size;
+ int xsize, ysize, planes, bit_count, compression, size_image, xres, yres;
+ int clr_used, clr_important, offbits;
+ i_img *im;
+
+ mm_log((1, "i_readbmp_wiol(ig %p)\n", ig));
+
+ io_glue_commit_types(ig);
+ i_clear_error();
+
+ if (!read_packed(ig, "CCVvvVVVVvvVVVVVV", &b_magic, &m_magic, &filesize,
+ &res1, &res2, &offbits, &infohead_size,
+ &xsize, &ysize, &planes,
+ &bit_count, &compression, &size_image, &xres, &yres,
+ &clr_used, &clr_important)) {
+ i_push_error(0, "file too short");
+ return 0;
+ }
+ if (b_magic != 'B' || m_magic != 'M' || infohead_size != INFOHEAD_SIZE
+ || planes != 1) {
+ i_push_error(0, "not a BMP file");
+ return 0;
+ }
+
+ mm_log((1, " bmp header: filesize %d offbits %d xsize %d ysize %d planes %d "
+ "bit_count %d compression %d size %d xres %d yres %d clr_used %d "
+ "clr_important %d\n", filesize, offbits, xsize, ysize, planes,
+ bit_count, compression, size_image, xres, yres, clr_used,
+ clr_important));
+
+ if (!i_int_check_image_file_limits(xsize, ysize, 3, sizeof(i_sample_t))) {
+ mm_log((1, "i_readbmp_wiol: image size exceeds limits\n"));
+ return NULL;
+ }
+
+ switch (bit_count) {
+ case 1:
+ im = read_1bit_bmp(ig, xsize, ysize, clr_used, compression, offbits);
+ break;
+
+ case 4:
+ im = read_4bit_bmp(ig, xsize, ysize, clr_used, compression, offbits);
+ break;
+
+ case 8:
+ im = read_8bit_bmp(ig, xsize, ysize, clr_used, compression, offbits);
+ break;
+
+ case 32:
+ case 24:
+ case 16:
+ im = read_direct_bmp(ig, xsize, ysize, bit_count, clr_used, compression,
+ offbits);
+ break;
+
+ default:
+ i_push_errorf(0, "unknown bit count for BMP file (%d)", bit_count);
+ return NULL;
+ }
+
+ if (im) {
+ /* store the resolution */
+ if (xres && !yres)
+ yres = xres;
+ else if (yres && !xres)
+ xres = yres;
+ if (xres) {
+ i_tags_set_float2(&im->tags, "i_xres", 0, xres * 0.0254, 4);
+ i_tags_set_float2(&im->tags, "i_yres", 0, yres * 0.0254, 4);
+ }
+ i_tags_addn(&im->tags, "bmp_compression", 0, compression);
+ i_tags_addn(&im->tags, "bmp_important_colors", 0, clr_important);
+ i_tags_addn(&im->tags, "bmp_used_colors", 0, clr_used);
+ i_tags_addn(&im->tags, "bmp_filesize", 0, filesize);
+ i_tags_addn(&im->tags, "bmp_bit_count", 0, bit_count);
+ i_tags_add(&im->tags, "i_format", 0, "bmp", 3, 0);
+ }
+
+ return im;
+}
+
+/*
+=back
+
+=head1 IMPLEMENTATION FUNCTIONS
+
+Internal functions used in the implementation.
+
+=over
+
+=item read_packed(ig, format, ...)
+
+Reads from the specified "file" the specified sizes. The format codes
+match those used by perl's pack() function, though only a few are
+implemented. In all cases the vararg arguement is an int *.
+
+Returns non-zero if all of the arguments were read.
+
+=cut
*/
static
int read_packed(io_glue *ig, char *format, ...) {
switch (*format) {
case 'v':
- if (ig->readcb(ig, buf, 2) == -1)
+ if (ig->readcb(ig, buf, 2) != 2)
return 0;
*p = buf[0] + (buf[1] << 8);
break;
case 'V':
- if (ig->readcb(ig, buf, 4) == -1)
+ if (ig->readcb(ig, buf, 4) != 4)
return 0;
*p = buf[0] + (buf[1] << 8) + (buf[2] << 16) + (buf[3] << 24);
break;
case 'C':
- if (ig->readcb(ig, buf, 1) == -1)
+ if (ig->readcb(ig, buf, 1) != 1)
return 0;
*p = buf[0];
break;
case 'c':
- if (ig->readcb(ig, buf, 1) == -1)
+ if (ig->readcb(ig, buf, 1) != 1)
return 0;
*p = (char)buf[0];
break;
+ case '3': /* extension - 24-bit number */
+ if (ig->readcb(ig, buf, 3) != 3)
+ return 0;
+ *p = buf[0] + (buf[1] << 8) + (buf[2] << 16);
+ break;
+
default:
m_fatal(1, "Unknown read_packed format code 0x%02x", *format);
}
return 1;
}
+/*
+=item write_packed(ig, format, ...)
+
+Writes packed data to the specified io_glue.
+
+Returns non-zero on success.
+
+=cut
+*/
+
static int
write_packed(io_glue *ig, char *format, ...) {
unsigned char buf[4];
break;
default:
- m_fatal(1, "Unknown read_packed format code 0x%02x", *format);
+ m_fatal(1, "Unknown write_packed format code 0x%02x", *format);
}
++format;
}
return 1;
}
-#define FILEHEAD_SIZE 14
-#define INFOHEAD_SIZE 40
-#define BI_RGB 0
-#define BI_RLE8 1
-#define BI_RLE4 2
-#define BI_BITFIELDS 3
+/*
+=item write_bmphead(ig, im, bit_count, data_size)
+
+Writes a Windows BMP header to the file.
+
+Returns non-zero on success.
+
+=cut
+*/
static
int write_bmphead(io_glue *ig, i_img *im, int bit_count, int data_size) {
if (!write_packed(ig, "CCVvvVVVVvvVVVVVV", 'B', 'M', data_size+offset,
0, 0, offset, INFOHEAD_SIZE, im->xsize, im->ysize, 1,
- bit_count, BI_RGB, 0, (int)xres, (int)yres,
- colors_used, 0)){
+ bit_count, BI_RGB, 0, (int)(xres+0.5), (int)(yres+0.5),
+ colors_used, colors_used)){
i_push_error(0, "cannot write bmp header");
return 0;
}
return 1;
}
+/*
+=item write_1bit_data(ig, im)
+
+Writes the image data as a 1-bit/pixel image.
+
+Returns non-zero on success.
+
+=cut
+*/
static int
write_1bit_data(io_glue *ig, i_img *im) {
i_palidx *line;
unsigned char *out;
int line_size = (im->xsize+7) / 8;
int x, y;
+ int unpacked_size;
/* round up to nearest multiple of four */
line_size = (line_size + 3) / 4 * 4;
if (!write_bmphead(ig, im, 1, line_size * im->ysize))
return 0;
- line = mymalloc(im->xsize + 8);
+ /* this shouldn't be an issue, but let's be careful */
+ unpacked_size = im->xsize + 8;
+ if (unpacked_size < im->xsize) {
+ i_push_error(0, "integer overflow during memory allocation");
+ return 0;
+ }
+ line = mymalloc(unpacked_size); /* checked 29jun05 tonyc */
memset(line + im->xsize, 0, 8);
-
- packed = mymalloc(line_size);
+
+ /* size allocated here is always much smaller than xsize, hence
+ can't overflow int */
+ packed = mymalloc(line_size); /* checked 29jun05 tonyc */
memset(packed, 0, line_size);
for (y = im->ysize-1; y >= 0; --y) {
myfree(packed);
myfree(line);
+ ig->closecb(ig);
+
return 1;
}
+/*
+=item write_4bit_data(ig, im)
+
+Writes the image data as a 4-bit/pixel image.
+
+Returns non-zero on success.
+
+=cut
+*/
static int
write_4bit_data(io_glue *ig, i_img *im) {
i_palidx *line;
unsigned char *out;
int line_size = (im->xsize+1) / 2;
int x, y;
+ int unpacked_size;
/* round up to nearest multiple of four */
line_size = (line_size + 3) / 4 * 4;
if (!write_bmphead(ig, im, 4, line_size * im->ysize))
return 0;
- line = mymalloc(im->xsize + 2);
+ /* this shouldn't be an issue, but let's be careful */
+ unpacked_size = im->xsize + 2;
+ if (unpacked_size < im->xsize) {
+ i_push_error(0, "integer overflow during memory allocation");
+ return 0;
+ }
+ line = mymalloc(unpacked_size); /* checked 29jun05 tonyc */
memset(line + im->xsize, 0, 2);
- packed = mymalloc(line_size);
+ /* size allocated here is always much smaller than xsize, hence
+ can't overflow int */
+ packed = mymalloc(line_size); /* checked 29jun05 tonyc */
memset(packed, 0, line_size);
for (y = im->ysize-1; y >= 0; --y) {
myfree(packed);
myfree(line);
+ ig->closecb(ig);
+
return 1;
}
+/*
+=item write_8bit_data(ig, im)
+
+Writes the image data as a 8-bit/pixel image.
+
+Returns non-zero on success.
+
+=cut
+*/
static int
write_8bit_data(io_glue *ig, i_img *im) {
i_palidx *line;
int line_size = im->xsize;
- int x, y;
+ int y;
+ int unpacked_size;
/* round up to nearest multiple of four */
line_size = (line_size + 3) / 4 * 4;
if (!write_bmphead(ig, im, 8, line_size * im->ysize))
return 0;
- line = mymalloc(im->xsize + 4);
+ /* this shouldn't be an issue, but let's be careful */
+ unpacked_size = im->xsize + 4;
+ if (unpacked_size < im->xsize) {
+ i_push_error(0, "integer overflow during memory allocation");
+ return 0;
+ }
+ line = mymalloc(unpacked_size); /* checked 29jun05 tonyc */
memset(line + im->xsize, 0, 4);
for (y = im->ysize-1; y >= 0; --y) {
}
myfree(line);
+ ig->closecb(ig);
+
return 1;
}
static int bgr_chans[] = { 2, 1, 0, };
static int grey_chans[] = { 0, 0, 0, };
+/*
+=item write_24bit_data(ig, im)
+
+Writes the image data as a 24-bit/pixel image.
+
+Returns non-zero on success.
+
+=cut
+*/
static int
write_24bit_data(io_glue *ig, i_img *im) {
int *chans;
unsigned char *samples;
- int x, y;
+ int y;
int line_size = 3 * im->xsize;
+
+ /* just in case we implement a direct format with 2bytes/pixel
+ (unlikely though) */
+ if (line_size / 3 != im->xsize) {
+ i_push_error(0, "integer overflow during memory allocation");
+ return 0;
+ }
line_size = (line_size + 3) / 4 * 4;
if (!write_bmphead(ig, im, 24, line_size * im->ysize))
return 0;
chans = im->channels >= 3 ? bgr_chans : grey_chans;
- samples = mymalloc(line_size);
+ samples = mymalloc(line_size); /* checked 29jun05 tonyc */
+ memset(samples, 0, line_size);
for (y = im->ysize-1; y >= 0; --y) {
i_gsamp(im, 0, im->xsize, y, samples, chans, 3);
if (ig->writecb(ig, samples, line_size) < 0) {
}
myfree(samples);
+ ig->closecb(ig);
+
return 1;
}
-/* no support for writing compressed (RLE8 or RLE4) BMP files */
-int
-i_writebmp_wiol(i_img *im, io_glue *ig) {
- io_glue_commit_types(ig);
- i_clear_error();
+/*
+=item read_bmp_pal(ig, im, count)
- /* pick a format */
- if (im->type == i_direct_type) {
- return write_24bit_data(ig, im);
- }
- else {
- int pal_size;
+Reads count palette entries from the file and add them to the image.
- /* must be paletted */
- pal_size = i_colorcount(im);
- if (pal_size <= 2) {
- return write_1bit_data(ig, im);
- }
- else if (pal_size <= 16) {
- return write_4bit_data(ig, im);
- }
- else {
- return write_8bit_data(ig, im);
- }
- }
-}
+Returns non-zero on success.
+=cut
+*/
static int
read_bmp_pal(io_glue *ig, i_img *im, int count) {
int i;
c.channel[0] = r;
c.channel[1] = g;
c.channel[2] = b;
- if (i_addcolors(im, &c, 1) < 0)
+ if (i_addcolors(im, &c, 1) < 0) {
+ i_push_error(0, "out of space in image palette");
return 0;
+ }
}
return 1;
}
+/*
+=item read_1bit_bmp(ig, xsize, ysize, clr_used, compression, offbits)
+
+Reads in the palette and image data for a 1-bit/pixel image.
+
+Returns the image or NULL.
+
+=cut
+*/
static i_img *
-read_1bit_bmp(io_glue *ig, int xsize, int ysize, int clr_used) {
+read_1bit_bmp(io_glue *ig, int xsize, int ysize, int clr_used,
+ int compression, long offbits) {
i_img *im;
int x, y, lasty, yinc;
i_palidx *line, *p;
unsigned char *packed;
int line_size = (xsize + 7)/8;
- int byte, bit;
+ int bit;
unsigned char *in;
+ long base_offset;
+
+ if (compression != BI_RGB) {
+ i_push_errorf(0, "unknown 1-bit BMP compression (%d)", compression);
+ return NULL;
+ }
+ if (xsize + 8 < xsize) { /* if there was overflow */
+ /* we check with 8 because we allocate that much for the decoded
+ line buffer */
+ i_push_error(0, "integer overflow during memory allocation");
+ return NULL;
+ }
+
+ /* if xsize+7 is ok then (xsize+7)/8 will be and the minor
+ adjustments below won't make it overflow */
line_size = (line_size+3) / 4 * 4;
if (ysize > 0) {
lasty = ysize;
yinc = 1;
}
+ if (!clr_used)
+ clr_used = 2;
+ if (clr_used < 0 || clr_used > 2) {
+ i_push_errorf(0, "out of range colors used (%d)", clr_used);
+ return NULL;
+ }
+
+ base_offset = FILEHEAD_SIZE + INFOHEAD_SIZE + clr_used * 4;
+ if (offbits < base_offset) {
+ i_push_errorf(0, "image data offset too small (%ld)", offbits);
+ return NULL;
+ }
+
im = i_img_pal_new(xsize, ysize, 3, 256);
+ if (!im)
+ return NULL;
if (!read_bmp_pal(ig, im, clr_used)) {
i_img_destroy(im);
return NULL;
}
- packed = mymalloc(line_size);
- line = mymalloc(xsize+8);
+ if (offbits > base_offset) {
+ /* this will be slow if the offset is large, but that should be
+ rare */
+ char buffer;
+ while (base_offset < offbits) {
+ if (ig->readcb(ig, &buffer, 1) != 1) {
+ i_img_destroy(im);
+ i_push_error(0, "failed skipping to image data offset");
+ return NULL;
+ }
+ ++base_offset;
+ }
+ }
+
+ i_tags_add(&im->tags, "bmp_compression_name", 0, "BI_RGB", -1, 0);
+
+ packed = mymalloc(line_size); /* checked 29jun05 tonyc */
+ line = mymalloc(xsize+8); /* checked 29jun05 tonyc */
while (y != lasty) {
if (ig->readcb(ig, packed, line_size) != line_size) {
myfree(packed);
myfree(line);
- i_push_error(0, "reading 1-bit bmp data");
+ i_push_error(0, "failed reading 1-bit bmp data");
i_img_destroy(im);
return NULL;
}
y += yinc;
}
+ myfree(packed);
+ myfree(line);
return im;
}
-#if 0
+/*
+=item read_4bit_bmp(ig, xsize, ysize, clr_used, compression)
+
+Reads in the palette and image data for a 4-bit/pixel image.
+
+Returns the image or NULL.
+
+Hopefully this will be combined with the following function at some
+point.
+
+=cut
+*/
static i_img *
-read_4bit_bmp(io_glue *ig, int xsize, int ysize, int clr_used) {
+read_4bit_bmp(io_glue *ig, int xsize, int ysize, int clr_used,
+ int compression, long offbits) {
i_img *im;
int x, y, lasty, yinc;
i_palidx *line, *p;
unsigned char *packed;
int line_size = (xsize + 1)/2;
unsigned char *in;
+ int size, i;
+ long base_offset;
+ /* line_size is going to be smaller than xsize in most cases (and
+ when it's not, xsize is itself small), and hence not overflow */
line_size = (line_size+3) / 4 * 4;
if (ysize > 0) {
lasty = ysize;
yinc = 1;
}
+ if (!clr_used)
+ clr_used = 16;
+
+ if (clr_used > 16 || clr_used < 0) {
+ i_push_errorf(0, "out of range colors used (%d)", clr_used);
+ return NULL;
+ }
+
+ base_offset = FILEHEAD_SIZE + INFOHEAD_SIZE + clr_used * 4;
+ if (offbits < base_offset) {
+ i_push_errorf(0, "image data offset too small (%ld)", offbits);
+ return NULL;
+ }
+
im = i_img_pal_new(xsize, ysize, 3, 256);
+ if (!im) /* error should have been pushed already */
+ return NULL;
if (!read_bmp_pal(ig, im, clr_used)) {
i_img_destroy(im);
return NULL;
}
- packed = mymalloc(line_size);
- line = mymalloc(xsize+1);
+ if (offbits > base_offset) {
+ /* this will be slow if the offset is large, but that should be
+ rare */
+ char buffer;
+ while (base_offset < offbits) {
+ if (ig->readcb(ig, &buffer, 1) != 1) {
+ i_img_destroy(im);
+ i_push_error(0, "failed skipping to image data offset");
+ return NULL;
+ }
+ ++base_offset;
+ }
+ }
+
+ if (line_size < 260)
+ packed = mymalloc(260); /* checked 29jun05 tonyc */
+ else
+ packed = mymalloc(line_size); /* checked 29jun05 tonyc */
+ /* xsize won't approach MAXINT */
+ line = mymalloc(xsize+1); /* checked 29jun05 tonyc */
if (compression == BI_RGB) {
+ i_tags_add(&im->tags, "bmp_compression_name", 0, "BI_RGB", -1, 0);
while (y != lasty) {
if (ig->readcb(ig, packed, line_size) != line_size) {
myfree(packed);
myfree(line);
- i_push_error(0, "reading 4-bit bmp data");
+ i_push_error(0, "failed reading 4-bit bmp data");
i_img_destroy(im);
return NULL;
}
i_ppal(im, 0, xsize, y, line);
y += yinc;
}
+ myfree(packed);
+ myfree(line);
}
else if (compression == BI_RLE4) {
- return 0;
+ int read_size;
+ int count;
+
+ i_tags_add(&im->tags, "bmp_compression_name", 0, "BI_RLE4", -1, 0);
+ x = 0;
+ while (1) {
+ /* there's always at least 2 bytes in a sequence */
+ if (ig->readcb(ig, packed, 2) != 2) {
+ myfree(packed);
+ myfree(line);
+ i_push_error(0, "missing data during decompression");
+ i_img_destroy(im);
+ return NULL;
+ }
+ else if (packed[0]) {
+ line[0] = packed[1] >> 4;
+ line[1] = packed[1] & 0x0F;
+ for (i = 0; i < packed[0]; i += 2) {
+ if (i < packed[0]-1)
+ i_ppal(im, x, x+2, y, line);
+ else
+ i_ppal(im, x, x+(packed[0]-i), y, line);
+ x += 2;
+ }
+ } else {
+ switch (packed[1]) {
+ case BMPRLE_ENDOFLINE:
+ x = 0;
+ y += yinc;
+ break;
+
+ case BMPRLE_ENDOFBMP:
+ myfree(packed);
+ myfree(line);
+ return im;
+
+ case BMPRLE_DELTA:
+ if (ig->readcb(ig, packed, 2) != 2) {
+ myfree(packed);
+ myfree(line);
+ i_push_error(0, "missing data during decompression");
+ i_img_destroy(im);
+ return NULL;
+ }
+ x += packed[0];
+ y += yinc * packed[1];
+ break;
+
+ default:
+ count = packed[1];
+ size = (count + 1) / 2;
+ read_size = (size+1) / 2 * 2;
+ if (ig->readcb(ig, packed, read_size) != read_size) {
+ myfree(packed);
+ myfree(line);
+ i_push_error(0, "missing data during decompression");
+ /*i_img_destroy(im);*/
+ return im;
+ }
+ for (i = 0; i < size; ++i) {
+ line[0] = packed[i] >> 4;
+ line[1] = packed[i] & 0xF;
+ i_ppal(im, x, x+2, y, line);
+ x += 2;
+ }
+ break;
+ }
+ }
+ }
+ }
+ else { /*if (compression == BI_RLE4) {*/
+ myfree(packed);
+ myfree(line);
+ i_push_errorf(0, "unknown 4-bit BMP compression (%d)", compression);
+ i_img_destroy(im);
+ return NULL;
}
return im;
}
-#endif
+/*
+=item read_8bit_bmp(ig, xsize, ysize, clr_used, compression)
-i_img *
-i_readbmp_wiol(io_glue *ig) {
-#if 0
- int b_magic, m_magic, filesize, dummy, infohead_size;
- int xsize, ysize, planes, bit_count, compression, size_image, xres, yres;
- int clr_used;
+Reads in the palette and image data for a 8-bit/pixel image.
+
+Returns the image or NULL.
+
+=cut
+*/
+static i_img *
+read_8bit_bmp(io_glue *ig, int xsize, int ysize, int clr_used,
+ int compression, long offbits) {
i_img *im;
+ int x, y, lasty, yinc;
+ i_palidx *line;
+ int line_size = xsize;
+ long base_offset;
+
+ line_size = (line_size+3) / 4 * 4;
+ if (line_size < xsize) { /* if it overflowed (unlikely, but check) */
+ i_push_error(0, "integer overflow during memory allocation");
+ return NULL;
+ }
+
+ if (ysize > 0) {
+ y = ysize-1;
+ lasty = -1;
+ yinc = -1;
+ }
+ else {
+ /* when ysize is -ve it's a top-down image */
+ ysize = -ysize;
+ y = 0;
+ lasty = ysize;
+ yinc = 1;
+ }
+ if (!clr_used)
+ clr_used = 256;
+ if (clr_used > 256 || clr_used < 0) {
+ i_push_errorf(0, "out of range colors used (%d)", clr_used);
+ return NULL;
+ }
+
+ base_offset = FILEHEAD_SIZE + INFOHEAD_SIZE + clr_used * 4;
+ if (offbits < base_offset) {
+ i_push_errorf(0, "image data offset too small (%ld)", offbits);
+ return NULL;
+ }
+
+ im = i_img_pal_new(xsize, ysize, 3, 256);
+ if (!im)
+ return NULL;
+ if (!read_bmp_pal(ig, im, clr_used)) {
+ i_img_destroy(im);
+ return NULL;
+ }
+
+ if (offbits > base_offset) {
+ /* this will be slow if the offset is large, but that should be
+ rare */
+ char buffer;
+ while (base_offset < offbits) {
+ if (ig->readcb(ig, &buffer, 1) != 1) {
+ i_img_destroy(im);
+ i_push_error(0, "failed skipping to image data offset");
+ return NULL;
+ }
+ ++base_offset;
+ }
+ }
- io_glue_commit_types(ig);
- i_clear_error();
+ line = mymalloc(line_size); /* checked 29jun05 tonyc */
+ if (compression == BI_RGB) {
+ i_tags_add(&im->tags, "bmp_compression_name", 0, "BI_RGB", -1, 0);
+ while (y != lasty) {
+ if (ig->readcb(ig, line, line_size) != line_size) {
+ myfree(line);
+ i_push_error(0, "failed reading 8-bit bmp data");
+ i_img_destroy(im);
+ return NULL;
+ }
+ i_ppal(im, 0, xsize, y, line);
+ y += yinc;
+ }
+ myfree(line);
+ }
+ else if (compression == BI_RLE8) {
+ int read_size;
+ int count;
+ unsigned char packed[2];
- if (!read_packed(ig, "CCVvvVVVVvvVVVVV", &b_magic, &m_magic, &filesize,
- &dummy, &dummy, &infohead_size, &xsize, &ysize, &planes,
- &bit_count, &compression, &size_image, &xres, &yres,
- &clr_used, &dummy)) {
- i_push_error(0, "file too short");
- return 0;
+ i_tags_add(&im->tags, "bmp_compression_name", 0, "BI_RLE8", -1, 0);
+ x = 0;
+ while (1) {
+ /* there's always at least 2 bytes in a sequence */
+ if (ig->readcb(ig, packed, 2) != 2) {
+ myfree(line);
+ i_push_error(0, "missing data during decompression");
+ i_img_destroy(im);
+ return NULL;
+ }
+ if (packed[0]) {
+ memset(line, packed[1], packed[0]);
+ i_ppal(im, x, x+packed[0], y, line);
+ x += packed[0];
+ } else {
+ switch (packed[1]) {
+ case BMPRLE_ENDOFLINE:
+ x = 0;
+ y += yinc;
+ break;
+
+ case BMPRLE_ENDOFBMP:
+ myfree(line);
+ return im;
+
+ case BMPRLE_DELTA:
+ if (ig->readcb(ig, packed, 2) != 2) {
+ myfree(line);
+ i_push_error(0, "missing data during decompression");
+ i_img_destroy(im);
+ return NULL;
+ }
+ x += packed[0];
+ y += yinc * packed[1];
+ break;
+
+ default:
+ count = packed[1];
+ read_size = (count+1) / 2 * 2;
+ if (ig->readcb(ig, line, read_size) != read_size) {
+ myfree(line);
+ i_push_error(0, "missing data during decompression");
+ i_img_destroy(im);
+ return NULL;
+ }
+ i_ppal(im, x, x+count, y, line);
+ x += count;
+ break;
+ }
+ }
+ }
}
- if (b_magic != 'B' || m_magic != 'M' || infohead_size != INFOHEAD_SIZE
- || planes != 1) {
- i_push_error(0, "not a BMP file");
- return 0;
+ else {
+ myfree(line);
+ i_push_errorf(0, "unknown 8-bit BMP compression (%d)", compression);
+ i_img_destroy(im);
+ return NULL;
}
+
+ return im;
+}
+
+struct bm_masks {
+ unsigned masks[3];
+ int shifts[3];
+};
+static struct bm_masks std_masks[] =
+{
+ { /* 16-bit */
+ { 0770000, 00007700, 00000077, },
+ { 10, 4, -2, },
+ },
+ { /* 24-bit */
+ { 0xFF0000, 0x00FF00, 0x0000FF, },
+ { 16, 8, 0, },
+ },
+ { /* 32-bit */
+ { 0xFF0000, 0x00FF00, 0x0000FF, },
+ { 16, 8, 0, },
+ },
+};
+
+/*
+=item read_direct_bmp(ig, xsize, ysize, bit_count, clr_used, compression)
+
+Skips the palette and reads in the image data for a direct colour image.
+
+Returns the image or NULL.
+
+=cut
+*/
+static i_img *
+read_direct_bmp(io_glue *ig, int xsize, int ysize, int bit_count,
+ int clr_used, int compression, long offbits) {
+ i_img *im;
+ int x, y, lasty, yinc;
+ i_color *line, *p;
+ int pix_size = bit_count / 8;
+ int line_size = xsize * pix_size;
+ struct bm_masks masks;
+ char unpack_code[2] = "";
+ int i;
+ int extras;
+ char junk[4];
+ const char *compression_name;
+ int bytes;
+ long base_offset = FILEHEAD_SIZE + INFOHEAD_SIZE;
- switch (bit_count) {
- case 1:
- im = read_1bit_bmp(ig, xsize, ysize, clr_used);
- break;
+ unpack_code[0] = *("v3V"+pix_size-2);
+ unpack_code[1] = '\0';
- case 4:
- im = read_4bit_bmp(ig, clr_used, compression);
- break;
+ line_size = (line_size+3) / 4 * 4;
+ extras = line_size - xsize * pix_size;
- case 8:
- im = read_8bit_bmp(ig, clr_used, compression);
- break;
+ if (ysize > 0) {
+ y = ysize-1;
+ lasty = -1;
+ yinc = -1;
+ }
+ else {
+ /* when ysize is -ve it's a top-down image */
+ ysize = -ysize;
+ y = 0;
+ lasty = ysize;
+ yinc = 1;
+ }
+ if (compression == BI_RGB) {
+ compression_name = "BI_RGB";
+ masks = std_masks[pix_size-2];
+
+ /* there's a potential "palette" after the header */
+ for (i = 0; i < clr_used; ++clr_used) {
+ char buf[4];
+ if (ig->readcb(ig, buf, 4) != 4) {
+ i_push_error(0, "skipping colors");
+ return 0;
+ }
+ base_offset += 4;
+ }
+ }
+ else if (compression == BI_BITFIELDS) {
+ int pos, bit;
+ compression_name = "BI_BITFIELDS";
- case 32:
- case 24:
- case 16:
- im = read_direct_bmp(ig, clr_used, compression);
- break;
+ for (i = 0; i < 3; ++i) {
+ if (!read_packed(ig, "V", masks.masks+i)) {
+ i_push_error(0, "reading pixel masks");
+ return 0;
+ }
+ /* work out a shift for the mask */
+ pos = 0;
+ bit = masks.masks[i] & -masks.masks[i];
+ while (bit) {
+ ++pos;
+ bit >>= 1;
+ }
+ masks.shifts[i] = pos - 8;
+ }
+ base_offset += 4 * 4;
+ }
+ else {
+ i_push_errorf(0, "unknown 24-bit BMP compression (%d)", compression);
+ return NULL;
+ }
+
+ if (offbits > base_offset) {
+ /* this will be slow if the offset is large, but that should be
+ rare */
+ char buffer;
+ while (base_offset < offbits) {
+ if (ig->readcb(ig, &buffer, 1) != 1) {
+ i_push_error(0, "failed skipping to image data offset");
+ return NULL;
+ }
+ ++base_offset;
+ }
+ }
+
+ im = i_img_empty(NULL, xsize, ysize);
+ if (!im)
+ return NULL;
+
+ i_tags_add(&im->tags, "bmp_compression_name", 0, compression_name, -1, 0);
+
+ /* I wasn't able to make this overflow in testing, but better to be
+ safe */
+ bytes = sizeof(i_color) * xsize;
+ if (bytes / sizeof(i_color) != xsize) {
+ i_img_destroy(im);
+ i_push_error(0, "integer overflow calculating buffer size");
+ return NULL;
}
-#endif
- return 0;
+ line = mymalloc(bytes); /* checked 29jun05 tonyc */
+ while (y != lasty) {
+ p = line;
+ for (x = 0; x < xsize; ++x) {
+ unsigned pixel;
+ if (!read_packed(ig, unpack_code, &pixel)) {
+ i_push_error(0, "failed reading image data");
+ myfree(line);
+ i_img_destroy(im);
+ return NULL;
+ }
+ for (i = 0; i < 3; ++i) {
+ if (masks.shifts[i] > 0)
+ p->channel[i] = (pixel & masks.masks[i]) >> masks.shifts[i];
+ else
+ p->channel[i] = (pixel & masks.masks[i]) << -masks.shifts[i];
+ }
+ ++p;
+ }
+ i_plin(im, 0, xsize, y, line);
+ if (extras)
+ ig->readcb(ig, junk, extras);
+ y += yinc;
+ }
+ myfree(line);
+
+ return im;
}
+
+/*
+=head1 SEE ALSO
+
+Imager(3)
+
+=head1 AUTHOR
+
+Tony Cook <tony@develop-help.com>
+
+=head1 RESTRICTIONS
+
+Cannot save as compressed BMP.
+
+=head1 BUGS
+
+Doesn't handle OS/2 bitmaps.
+
+16-bit/pixel images haven't been tested. (I need an image).
+
+BI_BITFIELDS compression hasn't been tested (I need an image).
+
+The header handling for paletted images needs to be refactored
+
+=cut
+*/
projects / imager.git / blobdiff