i64 dbuf_geti32le_p(dbuf *f, i64 *ppos)
{
i64 n;
n = dbuf_geti32le(f, *ppos);
(*ppos) += 4;
return n;
}
// Gathers information about a DIB.
// If DE_BMPINFO_HAS_FILEHEADER flag is set, pos points to the BITMAPFILEHEADER.
// Otherwise, it points to the BITMAPINFOHEADER.
// Caller allocates bi.
// Returns 0 if BMP is invalid.
int de_fmtutil_get_bmpinfo(deark *c, dbuf *f, struct de_bmpinfo *bi, i64 pos,
i64 len, unsigned int flags)
{
i64 fhs; // file header size
i64 bmih_pos;
struct de_fourcc cmpr4cc;
char cmprname_dbgstr[80];
de_zeromem(bi, sizeof(struct de_bmpinfo));
de_zeromem(&cmpr4cc, sizeof(struct de_fourcc));
fhs = (flags & DE_BMPINFO_HAS_FILEHEADER) ? 14 : 0;
if(fhs+len < 16) return 0;
if(fhs) {
if(flags & DE_BMPINFO_HAS_HOTSPOT) {
bi->hotspot_x = dbuf_getu16le(f, pos+6);
bi->hotspot_y = dbuf_getu16le(f, pos+8);
de_dbg(c, "hotspot: (%d,%d)", (int)bi->hotspot_x, (int)bi->hotspot_y);
}
bi->bitsoffset = dbuf_getu32le(f, pos+10);
de_dbg(c, "bits offset: %d", (int)bi->bitsoffset);
}
bmih_pos = pos + fhs;
bi->infohdrsize = dbuf_getu32le(f, bmih_pos);
if(bi->infohdrsize==0x474e5089 && (flags & DE_BMPINFO_ICO_FORMAT)) {
// We don't examine PNG-formatted icons, but we can identify them.
bi->infohdrsize = 0;
bi->file_format = DE_BMPINFO_FMT_PNG;
return 1;
}
de_dbg(c, "info header size: %d", (int)bi->infohdrsize);
if(bi->infohdrsize==12) {
bi->bytes_per_pal_entry = 3;
bi->width = dbuf_getu16le(f, bmih_pos+4);
bi->height = dbuf_getu16le(f, bmih_pos+6);
bi->bitcount = dbuf_getu16le(f, bmih_pos+10);
}
else if(bi->infohdrsize>=16 && bi->infohdrsize<=124) {
bi->bytes_per_pal_entry = 4;
bi->width = dbuf_getu32le(f, bmih_pos+4);
bi->height = dbuf_geti32le(f, bmih_pos+8);
if(bi->height<0) {
bi->is_topdown = 1;
bi->height = -bi->height;
}
bi->bitcount = dbuf_getu16le(f, bmih_pos+14);
if(bi->infohdrsize>=20) {
bi->compression_field = (u32)dbuf_getu32le(f, bmih_pos+16);
if(flags & DE_BMPINFO_CMPR_IS_4CC) {
dbuf_read_fourcc(f, bmih_pos+16, &cmpr4cc, 4, 0x0);
}
}
if(bi->infohdrsize>=24) {
bi->sizeImage_field = dbuf_getu32le(f, bmih_pos+20);
}
if(bi->infohdrsize>=36) {
bi->pal_entries = dbuf_getu32le(f, bmih_pos+32);
}
}
else {
return 0;
}
if(flags & DE_BMPINFO_ICO_FORMAT) bi->height /= 2;
if(bi->bitcount>=1 && bi->bitcount<=8) {
if(bi->pal_entries==0) {
bi->pal_entries = (i64)(1<<(unsigned int)bi->bitcount);
}
// I think the NumColors field (in icons) is supposed to be the maximum number of
// colors implied by the bit depth, not the number of colors in the palette.
bi->num_colors = (i64)(1<<(unsigned int)bi->bitcount);
}
else {
// An arbitrary value. All that matters is that it's >=256.
bi->num_colors = 16777216;
}
de_dbg_dimensions(c, bi->width, bi->height);
de_dbg(c, "bit count: %d", (int)bi->bitcount);
if((flags & DE_BMPINFO_CMPR_IS_4CC) && (bi->compression_field>0xffff)) {
de_snprintf(cmprname_dbgstr, sizeof(cmprname_dbgstr), "'%s'", cmpr4cc.id_dbgstr);
}
else {
de_fmtutil_get_bmp_compression_name(bi->compression_field,
cmprname_dbgstr, sizeof(cmprname_dbgstr), 0);
}
de_dbg(c, "compression: %u (%s)", (unsigned int)bi->compression_field, cmprname_dbgstr);
if(bi->sizeImage_field!=0) {
de_dbg(c, "sizeImage: %u", (unsigned int)bi->sizeImage_field);
}
de_dbg(c, "palette entries: %u", (unsigned int)bi->pal_entries);
if(bi->pal_entries>256 && bi->bitcount>8) {
de_warn(c, "Ignoring bad palette size (%u entries)", (unsigned int)bi->pal_entries);
bi->pal_entries = 0;
}
bi->pal_bytes = bi->bytes_per_pal_entry*bi->pal_entries;
bi->size_of_headers_and_pal = fhs + bi->infohdrsize + bi->pal_bytes;
// FIXME: cmpr type 3 doesn't always mean BITFIELDS
if(bi->compression_field==3) {
bi->size_of_headers_and_pal += 12; // BITFIELDS
}
bi->is_compressed = !((bi->compression_field==0) ||
(bi->compression_field==3 && bi->bitcount>1));
if(!de_good_image_dimensions(c, bi->width, bi->height)) {
return 0;
}
// TODO: This needs work, to decide how to handle compressed images.
// TODO: What about BI_BITFIELDS images?
if(bi->compression_field==0) {
// Try to figure out the true size of the resource, minus any padding.
bi->rowspan = ((bi->bitcount*bi->width +31)/32)*4;
bi->foreground_size = bi->rowspan * bi->height;
de_dbg(c, "foreground size: %d", (int)bi->foreground_size);
if(flags & DE_BMPINFO_ICO_FORMAT) {
bi->mask_rowspan = ((bi->width +31)/32)*4;
bi->mask_size = bi->mask_rowspan * bi->height;
de_dbg(c, "mask size: %d", (int)bi->mask_size);
}
else {
bi->mask_size = 0;
}
bi->total_size = bi->size_of_headers_and_pal + bi->foreground_size + bi->mask_size;
}
else {
// Don't try to figure out the true size of compressed or other unusual images.
bi->total_size = len;
}
return 1;
}
i64 dbuf_geti32x(dbuf *f, i64 pos, int is_le)
{
if(is_le) return dbuf_geti32le(f, pos);
return dbuf_geti32be(f, pos);
}
// Read any version of BITMAPINFOHEADER.
//
// Note: Some of this BMP parsing code is duplicated in the
// de_fmtutil_get_bmpinfo() library function. The BMP module's needs are
// not quite aligned with what that function is intended for, and it
// would be too messy to try to add the necessary features to it.
static int read_infoheader(deark *c, lctx *d, de_int64 pos)
{
de_int64 height_raw;
de_int64 clr_used_raw;
int cmpr_ok;
int retval = 0;
de_dbg(c, "info header at %d\n", (int)pos);
de_dbg_indent(c, 1);
de_dbg(c, "info header size: %d\n", (int)d->infohdrsize);
if(d->version==DE_BMPVER_OS2V1) {
d->width = de_getui16le(pos+4);
d->height = de_getui16le(pos+6);
}
else {
d->width = dbuf_geti32le(c->infile, pos+4);
height_raw = dbuf_geti32le(c->infile, pos+8);
if(height_raw<0) {
d->top_down = 1;
d->height = -height_raw;
}
else {
d->height = height_raw;
}
}
de_dbg(c, "dimensions: %dx%d\n", (int)d->width, (int)d->height);
if(!de_good_image_dimensions(c, d->width, d->height)) {
goto done;
}
if(d->top_down) {
de_dbg(c, "orientation: top-down\n");
}
// Already read, in detect_bmp_version()
de_dbg(c, "bits/pixel: %d\n", (int)d->bitcount);
if(d->bitcount!=0 && d->bitcount!=1 && d->bitcount!=2 && d->bitcount!=4 &&
d->bitcount!=8 && d->bitcount!=16 && d->bitcount!=24 && d->bitcount!=32)
{
de_err(c, "Bad bits/pixel: %d\n", (int)d->bitcount);
goto done;
}
if(d->version==DE_BMPVER_OS2V1) {
d->bytes_per_pal_entry = 3;
}
else {
// Already read, in detect_bmp_version()
de_dbg(c, "compression (etc.): %d\n", (int)d->compression_field);
d->bytes_per_pal_entry = 4;
}
d->compression_type = CMPR_NONE; // Temporary default
cmpr_ok = 0;
switch(d->compression_field) {
case 0: // BI_RGB
if(d->bitcount==16 || d->bitcount==32) {
d->bitfields_type = BF_DEFAULT;
}
d->compression_type = CMPR_NONE;
cmpr_ok = 1;
break;
case 1: // BI_RLE8
d->compression_type=CMPR_RLE8;
cmpr_ok = 1;
break;
case 2: // BI_RLE4
d->compression_type=CMPR_RLE4;
cmpr_ok = 1;
break;
case 3: // BI_BITFIELDS or Huffman_1D
if(d->version==DE_BMPVER_OS2V2) {
if(d->bitcount==1) {
d->compression_type=CMPR_HUFFMAN1D;
cmpr_ok = 1;
}
}
else if(d->bitcount==16 || d->bitcount==32) {
d->compression_type = CMPR_NONE;
cmpr_ok = 1;
if(d->infohdrsize>=52) {
d->bitfields_type = BF_IN_HEADER;
}
else {
d->bitfields_type = BF_SEGMENT;
d->bitfields_segment_len = 12;
}
}
break;
case 4: // BI_JPEG or RLE24
if(d->version==DE_BMPVER_OS2V2) {
if(d->bitcount==24) {
d->compression_type=CMPR_RLE24;
cmpr_ok = 1;
}
}
else {
d->compression_type=CMPR_JPEG;
cmpr_ok = 1;
}
break;
case 5: // BI_PNG
d->compression_type=CMPR_PNG;
cmpr_ok = 1;
break;
case 6: // BI_ALPHABITFIELDS
if(d->bitcount==16 || d->bitcount==32) {
d->compression_type = CMPR_NONE;
cmpr_ok = 1;
if(d->infohdrsize>=56) {
d->bitfields_type = BF_IN_HEADER;
}
else {
d->bitfields_type = BF_SEGMENT;
d->bitfields_segment_len = 16;
}
}
break;
}
if(!cmpr_ok) {
de_err(c, "Unsupported compression type: %d\n", (int)d->compression_field);
goto done;
}
if(d->infohdrsize>=24) {
d->size_image = de_getui32le(pos+20);
de_dbg(c, "biSizeImage: %d\n", (int)d->size_image);
}
if(d->infohdrsize>=32) {
d->xpelspermeter = dbuf_geti32le(c->infile, pos+24);
d->ypelspermeter = dbuf_geti32le(c->infile, pos+28);
de_dbg(c, "density: %dx%d pixels/meter\n", (int)d->xpelspermeter, (int)d->ypelspermeter);
}
if(d->infohdrsize>=36)
clr_used_raw = de_getui32le(pos+32);
else
clr_used_raw = 0;
if(d->bitcount>=1 && d->bitcount<=8 && clr_used_raw==0) {
d->pal_entries = ((de_int64)1)<<d->bitcount;
}
else {
d->pal_entries = clr_used_raw;
}
de_dbg(c, "number of palette colors: %d\n", (int)d->pal_entries);
// Note that after 40 bytes, WINV345 and OS2V2 header fields are different,
// so we have to pay more attention to the version.
if(d->bitfields_type==BF_IN_HEADER) {
do_read_bitfields(c, d, pos+40, d->infohdrsize>=56 ? 16 : 12);
}
if(d->bitfields_type==BF_DEFAULT) {
set_default_bitfields(c, d);
}
if(d->version==DE_BMPVER_WINV345 && d->infohdrsize>=108) {
dbuf_read_fourcc(c->infile, pos+56, &d->cstype4cc, 1);
de_dbg(c, "CSType: 0x%08x ('%s')\n", (unsigned int)d->cstype4cc.id,
d->cstype4cc.id_printable);
}
if(d->version==DE_BMPVER_WINV345 && d->infohdrsize>=124 &&
(d->cstype4cc.id==CODE_MBED || d->cstype4cc.id==CODE_LINK))
{
d->profile_offset_raw = de_getui32le(pos+112);
de_dbg(c, "profile offset: %d+%d\n", FILEHEADER_SIZE,
(int)d->profile_offset_raw);
d->profile_size = de_getui32le(pos+116);
de_dbg(c, "profile size: %d\n", (int)d->profile_size);
}
retval = 1;
done:
de_dbg_indent(c, -1);
return retval;
}
