/
bmp.c
1409 lines (1215 loc) · 33.4 KB
/
bmp.c
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#include <stdarg.h>
#include "imageri.h"
/*
=head1 NAME
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, int allow_incomplete);
static i_img *read_4bit_bmp(io_glue *ig, int xsize, int ysize, int clr_used,
int compression, long offbits, int allow_incomplete);
static i_img *read_8bit_bmp(io_glue *ig, int xsize, int ysize, int clr_used,
int compression, long offbits, int allow_incomplete);
static i_img *read_direct_bmp(io_glue *ig, int xsize, int ysize,
int bit_count, int clr_used, int compression,
long offbits, int allow_incomplete);
/*
=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 allow_incomplete) {
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 to be a BMP file");
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, abs(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,
allow_incomplete);
break;
case 4:
im = read_4bit_bmp(ig, xsize, ysize, clr_used, compression, offbits,
allow_incomplete);
break;
case 8:
im = read_8bit_bmp(ig, xsize, ysize, clr_used, compression, offbits,
allow_incomplete);
break;
case 32:
case 24:
case 16:
im = read_direct_bmp(ig, xsize, ysize, bit_count, clr_used, compression,
offbits, allow_incomplete);
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, ...) {
unsigned char buf[4];
va_list ap;
int *p;
va_start(ap, format);
while (*format) {
p = va_arg(ap, int *);
switch (*format) {
case 'v':
if (ig->readcb(ig, buf, 2) != 2)
return 0;
*p = buf[0] + (buf[1] << 8);
break;
case 'V':
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)
return 0;
*p = buf[0];
break;
case 'c':
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:
i_fatal(1, "Unknown read_packed format code 0x%02x", *format);
}
++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];
va_list ap;
int i;
va_start(ap, format);
while (*format) {
i = va_arg(ap, unsigned int);
switch (*format) {
case 'v':
buf[0] = i & 255;
buf[1] = i / 256;
if (ig->writecb(ig, buf, 2) == -1)
return 0;
break;
case 'V':
buf[0] = i & 0xFF;
buf[1] = (i >> 8) & 0xFF;
buf[2] = (i >> 16) & 0xFF;
buf[3] = (i >> 24) & 0xFF;
if (ig->writecb(ig, buf, 4) == -1)
return 0;
break;
case 'C':
case 'c':
buf[0] = i & 0xFF;
if (ig->writecb(ig, buf, 1) == -1)
return 0;
break;
default:
i_fatal(1, "Unknown write_packed format code 0x%02x", *format);
}
++format;
}
va_end(ap);
return 1;
}
/*
=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) {
double xres, yres;
int got_xres, got_yres, aspect_only;
int colors_used = 0;
int offset = FILEHEAD_SIZE + INFOHEAD_SIZE;
got_xres = i_tags_get_float(&im->tags, "i_xres", 0, &xres);
got_yres = i_tags_get_float(&im->tags, "i_yres", 0, &yres);
if (!i_tags_get_int(&im->tags, "i_aspect_only", 0,&aspect_only))
aspect_only = 0;
if (!got_xres) {
if (!got_yres)
xres = yres = 72;
else
xres = yres;
}
else {
if (!got_yres)
yres = xres;
}
if (xres <= 0 || yres <= 0)
xres = yres = 72;
if (aspect_only) {
/* scale so the smaller value is 72 */
double ratio;
if (xres < yres) {
ratio = 72.0 / xres;
}
else {
ratio = 72.0 / yres;
}
xres *= ratio;
yres *= ratio;
}
/* now to pels/meter */
xres *= 100.0/2.54;
yres *= 100.0/2.54;
if (im->type == i_palette_type) {
colors_used = i_colorcount(im);
offset += 4 * colors_used;
}
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+0.5), (int)(yres+0.5),
colors_used, colors_used)){
i_push_error(0, "cannot write bmp header");
return 0;
}
if (im->type == i_palette_type) {
int i;
i_color c;
for (i = 0; i < colors_used; ++i) {
i_getcolors(im, i, &c, 1);
if (im->channels >= 3) {
if (!write_packed(ig, "CCCC", c.channel[2], c.channel[1],
c.channel[0], 0)) {
i_push_error(0, "cannot write palette entry");
return 0;
}
}
else {
if (!write_packed(ig, "CCCC", c.channel[0], c.channel[0],
c.channel[0], 0)) {
i_push_error(0, "cannot write palette entry");
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 *packed;
int byte;
int mask;
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;
/* 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);
/* 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) {
i_gpal(im, 0, im->xsize, y, line);
mask = 0x80;
byte = 0;
out = packed;
for (x = 0; x < im->xsize; ++x) {
if (line[x])
byte |= mask;
if ((mask >>= 1) == 0) {
*out++ = byte;
byte = 0;
mask = 0x80;
}
}
if (mask != 0x80) {
*out++ = byte;
}
if (ig->writecb(ig, packed, line_size) < 0) {
myfree(packed);
myfree(line);
i_push_error(0, "writing 1 bit/pixel packed data");
return 0;
}
}
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 *packed;
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;
/* 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);
/* 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) {
i_gpal(im, 0, im->xsize, y, line);
out = packed;
for (x = 0; x < im->xsize; x += 2) {
*out++ = (line[x] << 4) + line[x+1];
}
if (ig->writecb(ig, packed, line_size) < 0) {
myfree(packed);
myfree(line);
i_push_error(0, "writing 4 bit/pixel packed data");
return 0;
}
}
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 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;
/* 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) {
i_gpal(im, 0, im->xsize, y, line);
if (ig->writecb(ig, line, line_size) < 0) {
myfree(line);
i_push_error(0, "writing 8 bit/pixel packed data");
return 0;
}
}
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 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); /* 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) {
i_push_error(0, "writing image data");
myfree(samples);
return 0;
}
}
myfree(samples);
ig->closecb(ig);
return 1;
}
/*
=item read_bmp_pal(ig, im, count)
Reads count palette entries from the file and add them to the image.
Returns non-zero on success.
=cut
*/
static int
read_bmp_pal(io_glue *ig, i_img *im, int count) {
int i;
int r, g, b, x;
i_color c;
for (i = 0; i < count; ++i) {
if (!read_packed(ig, "CCCC", &b, &g, &r, &x)) {
i_push_error(0, "reading BMP palette");
return 0;
}
c.channel[0] = r;
c.channel[1] = g;
c.channel[2] = b;
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,
int compression, long offbits, int allow_incomplete) {
i_img *im;
int x, y, lasty, yinc, start_y;
i_palidx *line, *p;
unsigned char *packed;
int line_size = (xsize + 7)/8;
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) {
start_y = ysize-1;
lasty = -1;
yinc = -1;
}
else {
/* when ysize is -ve it's a top-down image */
ysize = -ysize;
start_y = 0;
lasty = ysize;
yinc = 1;
}
y = start_y;
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;
}
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);
if (allow_incomplete) {
i_tags_setn(&im->tags, "i_incomplete", 1);
i_tags_setn(&im->tags, "i_lines_read", abs(start_y - y));
return im;
}
else {
i_push_error(0, "failed reading 1-bit bmp data");
i_img_destroy(im);
return NULL;
}
}
in = packed;
bit = 0x80;
p = line;
for (x = 0; x < xsize; ++x) {
*p++ = (*in & bit) ? 1 : 0;
bit >>= 1;
if (!bit) {
++in;
bit = 0x80;
}
}
i_ppal(im, 0, xsize, y, line);
y += yinc;
}
myfree(packed);
myfree(line);
return im;
}
/*
=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,
int compression, long offbits, int allow_incomplete) {
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;
int starty;
/* 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) {
starty = ysize-1;
lasty = -1;
yinc = -1;
}
else {
/* when ysize is -ve it's a top-down image */
ysize = -ysize;
starty = 0;
lasty = ysize;
yinc = 1;
}
y = starty;
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;
}
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);
if (allow_incomplete) {
i_tags_setn(&im->tags, "i_incomplete", 1);
i_tags_setn(&im->tags, "i_lines_read", abs(y - starty));
return im;
}
else {
i_push_error(0, "failed reading 4-bit bmp data");
i_img_destroy(im);
return NULL;
}
}
in = packed;
p = line;
for (x = 0; x < xsize; x+=2) {
*p++ = *in >> 4;
*p++ = *in & 0x0F;
++in;
}
i_ppal(im, 0, xsize, y, line);
y += yinc;
}
myfree(packed);
myfree(line);
}
else if (compression == BI_RLE4) {
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);
if (allow_incomplete) {
i_tags_setn(&im->tags, "i_incomplete", 1);
i_tags_setn(&im->tags, "i_lines_read", abs(y - starty));
return im;
}
else {
i_push_error(0, "missing data during decompression");
i_img_destroy(im);
return NULL;
}
}
else if (packed[0]) {
if (x + packed[0] > xsize) {
/* this file is corrupt */
myfree(packed);
myfree(line);
i_push_error(0, "invalid data during decompression");
i_img_destroy(im);
return NULL;
}
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);
if (allow_incomplete) {
i_tags_setn(&im->tags, "i_incomplete", 1);
i_tags_setn(&im->tags, "i_lines_read", abs(y - starty));
return im;
}
else {
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];
if (x + count > xsize) {
/* this file is corrupt */
myfree(packed);
myfree(line);
i_push_error(0, "invalid data during decompression");
i_img_destroy(im);
return NULL;
}
size = (count + 1) / 2;
read_size = (size+1) / 2 * 2;
if (ig->readcb(ig, packed, read_size) != read_size) {
myfree(packed);
myfree(line);
if (allow_incomplete) {
i_tags_setn(&im->tags, "i_incomplete", 1);
i_tags_setn(&im->tags, "i_lines_read", abs(y - starty));
return im;
}
else {
i_push_error(0, "missing data during decompression");
i_img_destroy(im);
return NULL;
}
}
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;
}