}
gdcmHeader::gdcmHeader (const char* InFilename) {
+ SetMaxSizeLoadElementValue(1024);
filename = InFilename;
Initialise();
fp=fopen(InFilename,"rw");
return;
}
VRHT *vr = new VRHT;
- (*vr)["AE"] = "Application Entity"; // 16 car max
- (*vr)["AS"] = "Age String"; // 4 car fixe
- (*vr)["AT"] = "Attribute Tag"; // 2 unsigned short int
- (*vr)["CS"] = "Code String"; // 16 car max
- (*vr)["DA"] = "Date"; // 8 car fixe
- (*vr)["DS"] = "Decimal String"; // Decimal codé Binaire 16 max
- (*vr)["DT"] = "Date Time"; // 26 car max
- (*vr)["FL"] = "Floating Point Single"; // 4 octets IEEE 754:1985
- (*vr)["FD"] = "Floating Point Double"; // 8 octets IEEE 754:1985
- (*vr)["IS"] = "Integer String"; // en format externe 12 max
- (*vr)["LO"] = "Long String"; // 64 octets max
- (*vr)["LT"] = "Long Text"; // 10240 max
- (*vr)["OB"] = "Other Byte String";
- (*vr)["OW"] = "Other Word String";
- (*vr)["PN"] = "Person Name";
- (*vr)["SH"] = "Short String"; // 16 car max
- (*vr)["SL"] = "Signed Long";
+ (*vr)["AE"] = "Application Entity"; // At most 16 bytes
+ (*vr)["AS"] = "Age String"; // Exactly 4 bytes
+ (*vr)["AT"] = "Attribute Tag"; // 2 16-bit unsigned short integers
+ (*vr)["CS"] = "Code String"; // At most 16 bytes
+ (*vr)["DA"] = "Date"; // Exactly 8 bytes
+ (*vr)["DS"] = "Decimal String"; // At most 16 bytes
+ (*vr)["DT"] = "Date Time"; // At most 26 bytes
+ (*vr)["FL"] = "Floating Point Single"; // 32-bit IEEE 754:1985 float
+ (*vr)["FD"] = "Floating Point Double"; // 64-bit IEEE 754:1985 double
+ (*vr)["IS"] = "Integer String"; // At most 12 bytes
+ (*vr)["LO"] = "Long String"; // At most 64 chars
+ (*vr)["LT"] = "Long Text"; // At most 10240 chars
+ (*vr)["OB"] = "Other Byte String"; // String of bytes (vr independant)
+ (*vr)["OW"] = "Other Word String"; // String of 16-bit words (vr dep)
+ (*vr)["PN"] = "Person Name"; // At most 64 chars
+ (*vr)["SH"] = "Short String"; // At most 16 chars
+ (*vr)["SL"] = "Signed Long"; // Exactly 4 bytes
(*vr)["SQ"] = "Sequence of Items"; // Not Applicable
- (*vr)["SS"] = "Signed Short"; // 2 octets
- (*vr)["ST"] = "Short Text"; // 1024 car max
- (*vr)["TM"] = "Time"; // 16 car max
- (*vr)["UI"] = "Unique Identifier"; // 64 car max
- (*vr)["UN"] = "Unknown";
- (*vr)["UT"] = "Unlimited Text"; // 2 puissance 32 -1 car max
- (*vr)["UL"] = "Unsigned Long "; // 4 octets fixe
- (*vr)["US"] = "Unsigned Short "; // 2 octets fixe
+ (*vr)["SS"] = "Signed Short"; // Exactly 2 bytes
+ (*vr)["ST"] = "Short Text"; // At most 1024 chars
+ (*vr)["TM"] = "Time"; // At most 16 bytes
+ (*vr)["UI"] = "Unique Identifier"; // At most 64 bytes
+ (*vr)["UL"] = "Unsigned Long "; // Exactly 4 bytes
+ (*vr)["UN"] = "Unknown"; // Any length of bytes
+ (*vr)["US"] = "Unsigned Short "; // Exactly 2 bytes
+ (*vr)["UT"] = "Unlimited Text"; // At most 2^32 -1 chars
dicom_vr = vr;
}
}
void gdcmHeader::SwitchSwapToBigEndian(void) {
- dbg.Verbose(0, "gdcmHeader::FindLength", "Switching to BigEndian mode.");
+ dbg.Verbose(1, "gdcmHeader::SwitchSwapToBigEndian",
+ "Switching to BigEndian mode.");
if ( sw == 0 ) {
sw = 4321;
return;
*/
void gdcmHeader::FindVR( ElValue *ElVal) {
+ if (filetype != ExplicitVR)
+ return;
+
char VR[3];
string vr;
int lgrLue;
// the case.
bool RealExplicit = true;
- if (filetype != ExplicitVR)
- return;
-
lgrLue=fread (&VR, (size_t)2,(size_t)1, fp);
VR[2]=0;
vr = string(VR);
RealExplicit = false;
if ( RealExplicit ) {
- if ( ElVal->IsVrUnknown() )
+ if ( ElVal->IsVrUnknown() ) {
+ // When not a dictionary entry, we can safely overwrite the vr.
ElVal->SetVR(vr);
+ return;
+ }
+ if ( ElVal->GetVR() == vr ) {
+ // The vr we just read and the dictionary agree. Nothing to do.
+ return;
+ }
+ // The vr present in the file and the dictionary disagree. We assume
+ // the file writer knew best and use the vr of the file. Since it would
+ // be unwise to overwrite the vr of a dictionary (since it would
+ // compromise it's next user), we need to clone the actual DictEntry
+ // and change the vr for the read one.
+ gdcmDictEntry* NewTag = new gdcmDictEntry(ElVal->GetGroup(),
+ ElVal->GetElement(),
+ vr,
+ "FIXME",
+ ElVal->GetName());
+ ElVal->SetDictEntry(NewTag);
return;
}
ElVal->SetLength(FoudLength);
}
-void gdcmHeader::FindLength( ElValue * ElVal) {
+guint32 gdcmHeader::FindLengthOB(void) {
+ // See PS 3.5-2001, section A.4 p. 49 on encapsulation of encoded pixel data.
+ guint16 g;
+ guint16 n;
+ long PositionOnEntry = ftell(fp);
+ bool FoundSequenceDelimiter = false;
+ guint32 TotalLength = 0;
+ guint32 ItemLength;
+
+ while ( ! FoundSequenceDelimiter) {
+ g = ReadInt16();
+ n = ReadInt16();
+ TotalLength += 4; // We even have to decount the group and element
+ if ( g != 0xfffe ) {
+ dbg.Verbose(1, "gdcmHeader::FindLengthOB: ",
+ "wrong group for an item sequence.");
+ throw Error::FileReadError(fp, "gdcmHeader::FindLengthOB");
+ }
+ if ( n == 0xe0dd )
+ FoundSequenceDelimiter = true;
+ else if ( n != 0xe000) {
+ dbg.Verbose(1, "gdcmHeader::FindLengthOB: ",
+ "wrong element for an item sequence.");
+ throw Error::FileReadError(fp, "gdcmHeader::FindLengthOB");
+ }
+ ItemLength = ReadInt32();
+ TotalLength += ItemLength + 4; // We add 4 bytes since we just read
+ // the ItemLength with ReadInt32
+ SkipBytes(ItemLength);
+ }
+ fseek(fp, PositionOnEntry, SEEK_SET);
+ return TotalLength;
+}
+
+void gdcmHeader::FindLength(ElValue * ElVal) {
guint16 element = ElVal->GetElement();
string vr = ElVal->GetVR();
guint16 length16;
if ( (filetype == ExplicitVR) && ! ElVal->IsImplicitVr() ) {
+
if ( (vr=="OB") || (vr=="OW") || (vr=="SQ") || (vr=="UN") ) {
-
- // The following two bytes are reserved, so we skip them,
- // and we proceed on reading the length on 4 bytes.
- fseek(fp, 2L,SEEK_CUR);
- FixFoundLength(ElVal, ReadInt32());
+ // The following reserved two bytes (see PS 3.5-2001, section
+ // 7.1.2 Data element structure with explicit vr p27) must be
+ // skipped before proceeding on reading the length on 4 bytes.
+ fseek(fp, 2L, SEEK_CUR);
+ guint32 length32 = ReadInt32();
+ if ( (vr == "OB") && (length32 == 0xffffffff) ) {
+ ElVal->SetLength(FindLengthOB());
+ return;
+ }
+ FixFoundLength(ElVal, length32);
return;
}
// We can tell the current file is encoded in big endian (like
// Data/US-RGB-8-epicard) when we find the "Transfer Syntax" tag
- // and it's value is the one of the encoding of a bie endian file.
+ // and it's value is the one of the encoding of a big endian file.
// In order to deal with such big endian encoded files, we have
// (at least) two strategies:
// * when we load the "Transfer Syntax" tag with value of big endian
// in little endian, and big endian coding only starts at the next
// group. The corresponding code can be hard to analyse and adds
// many additional unnecessary tests for regular tags.
- // * the second strategy consist to wait for trouble, that shall appear
+ // * the second strategy consist in waiting for trouble, that shall appear
// when we find the first group with big endian encoding. This is
// easy to detect since the length of a "Group Length" tag (the
// ones with zero as element number) has to be of 4 (0x0004). When we
return;
}
- // Either implicit VR or an explicit VR that (at least for this
- // element) lied a little bit. Length is on 4 bytes.
+ // Either implicit VR or a non DICOM conformal (see not below) explicit
+ // VR that ommited the VR of (at least) this element. Farts happen.
+ // [Note: according to the part 5, PS 3.5-2001, section 7.1 p25
+ // on Data elements "Implicit and Explicit VR Data Elements shall
+ // not coexist in a Data Set and Data Sets nested within it".]
+ // Length is on 4 bytes.
FixFoundLength(ElVal, ReadInt32());
}
-
/**
* \ingroup gdcmHeader
* \brief Swaps back the bytes of 4-byte long integer accordingly to
return (a);
}
-void gdcmHeader::SkipElementValue(ElValue * ElVal) {
+void gdcmHeader::SkipBytes(guint32 NBytes) {
//FIXME don't dump the returned value
- (void)fseek(fp, (long)ElVal->GetLength(), SEEK_CUR);
+ (void)fseek(fp, (long)NBytes, SEEK_CUR);
+}
+
+void gdcmHeader::SkipElementValue(ElValue * ElVal) {
+ SkipBytes(ElVal->GetLength());
+}
+
+void gdcmHeader::SetMaxSizeLoadElementValue(long NewSize) {
+ if (NewSize < 0)
+ return;
+ if ((guint32)NewSize >= (guint32)0xffffffff) {
+ MaxSizeLoadElementValue = 0xffffffff;
+ return;
+ }
+ MaxSizeLoadElementValue = NewSize;
}
/**
SkipLoad = true;
if ( SkipLoad ) {
+ // FIXME the following skip is not necessary
SkipElementValue(ElVal);
ElVal->SetLength(0);
ElVal->SetValue("gdcm::Skipped");
ElVal->SetValue("");
return;
}
+
+ // Values bigger than specified are not loaded.
+ if (length > MaxSizeLoadElementValue) {
+ ostringstream s;
+ s << "gdcm::NotLoaded.";
+ s << " Address:" << (long)ElVal->GetOffset();
+ s << " Length:" << ElVal->GetLength();
+ //mesg += " Length:" + ElVal->GetLength();
+ ElVal->SetValue(s.str());
+ return;
+ }
// When an integer is expected, read and convert the following two or
// four bytes properly i.e. as an integer as opposed to a string.
}
NewValue[length]= 0;
- // FIXME les elements trop long (seuil a fixer a la main) ne devraient
- // pas etre charge's !!!! Voir TODO.
item_read = fread(NewValue, (size_t)length, (size_t)1, fp);
if ( item_read != 1 ) {
g_free(NewValue);
git://git.creatis.insa-lyon.fr / gdcm.git / blobdiff