void
create_bg44_chunk(IFFByteStream &iff, const char *ckid, GUTF8String filespec)
{
static GP<IFFByteStream> bg44iff;
if (! bg44iff)
{
if (flag_contains_bg)
DjVuPrintErrorUTF8("%s","djvumake: Duplicate BGxx chunk\n");
int i=filespec.rsearch(':');
for (int j=i+1; i>0 && j<(int)filespec.length(); j++)
if (filespec[j] < '0' || filespec[j] > '9')
i = -1;
if (!i)
G_THROW("djvumake: no filename specified in first BG44 specification");
GUTF8String filename=(i<0)?filespec:GUTF8String(filespec, i);
const GURL::Filename::UTF8 url(filename);
const GP<ByteStream> gbs(ByteStream::create(url,"rb"));
if(!gbs)
{
G_THROW("djvumake: no such file as"+filename);
}
bg44iff = IFFByteStream::create(gbs);
GUTF8String chkid;
bg44iff->get_chunk(chkid);
if (chkid != "FORM:PM44" && chkid != "FORM:BM44")
G_THROW("djvumake: BG44 file has incorrect format (wrong IFF header)");
if (i>=0)
filespec = i+1+(const char *)filespec;
else
filespec = "99";
}
else
{
if (filespec.length() && filespec[0]!=':')
G_THROW("djvumake: filename specified in BG44 refinement");
filespec = 1+(const char *)filespec;
}
const char *s=filespec;
int nchunks = strtol((char *)s, (char **)&s, 10);
if (nchunks<1 || nchunks>99)
G_THROW("djvumake: invalid number of chunks in BG44 specification");
if (*s)
G_THROW("djvumake: invalid BG44 specification (syntax error)");
int flag = (nchunks>=99);
GUTF8String chkid;
while (nchunks-->0 && bg44iff->get_chunk(chkid))
{
if (chkid!="PM44" && chkid!="BM44")
{
DjVuPrintErrorUTF8("%s","djvumake: BG44 file contains unrecognized chunks (fixed)\n");
nchunks += 1;
bg44iff->close_chunk();
continue;
}
GP<ByteStream> gmbs=ByteStream::create();
ByteStream &mbs=*gmbs;
mbs.copy(*(bg44iff->get_bytestream()));
bg44iff->close_chunk();
mbs.seek(0);
if (mbs.readall((void*)&primary, sizeof(primary)) != sizeof(primary))
G_THROW("djvumake: BG44 file is corrupted (cannot read primary header)\n");
if (primary.serial == 0)
{
if (mbs.readall((void*)&secondary, sizeof(secondary)) != sizeof(secondary))
G_THROW("djvumake: BG44 file is corrupted (cannot read secondary header)\n");
int iw = (secondary.xhi<<8) + secondary.xlo;
int ih = (secondary.yhi<<8) + secondary.ylo;
int red;
for (red=1; red<=12; red++)
if (iw==(w+red-1)/red && ih==(h+red-1)/red)
break;
flag_contains_bg = red;
if (red>12)
DjVuPrintErrorUTF8("%s","djvumake: BG44 subsampling is not in [1..12] range\n");
}
mbs.seek(0);
iff.put_chunk(ckid);
iff.copy(mbs);
iff.close_chunk();
flag = 1;
}
if (!flag)
DjVuPrintErrorUTF8("%s","djvumake: no more chunks in BG44 file\n");
}
