-// $Header: /cvs/public/gdcm/src/Attic/gdcmHeader.cxx,v 1.87 2003/09/24 13:36:15 jpr Exp $
-
-//This is needed when compiling in debug mode
-#ifdef _MSC_VER
-//'identifier' : not all control paths return a value
-//#pragma warning ( disable : 4715 )
-// 'identifier' : class 'type' needs to have dll-interface to be used by
-// clients of class 'type2'
-#pragma warning ( disable : 4251 )
-// 'identifier' : identifier was truncated to 'number' characters in the
-// debug information
-#pragma warning ( disable : 4786 )
-#endif //_MSC_VER
-
-#include <stdio.h>
-#include <cerrno>
-// For nthos:
-#ifdef _MSC_VER
-#include <winsock.h>
-#else
-#include <netinet/in.h>
-#endif
-#include <cctype> // for isalpha
-#include <sstream>
-#include "gdcmUtil.h"
-#include "gdcmHeader.h"
-#include "gdcmTS.h"
-
-// Refer to gdcmHeader::CheckSwap()
-#define HEADER_LENGTH_TO_READ 256
-// Refer to gdcmHeader::SetMaxSizeLoadElementValue()
-//#define _MaxSizeLoadElementValue_ 1024
-#define _MaxSizeLoadElementValue_ 4096
-/**
- * \ingroup gdcmHeader
- * \brief
- */
-void gdcmHeader::Initialise(void) {
- dicom_vr = gdcmGlobal::GetVR();
- dicom_ts = gdcmGlobal::GetTS();
- Dicts = gdcmGlobal::GetDicts();
- RefPubDict = Dicts->GetDefaultPubDict();
- RefShaDict = (gdcmDict*)0;
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief
- * @param InFilename
- * @param exception_on_error
- */
-gdcmHeader::gdcmHeader(const char *InFilename, bool exception_on_error) {
- SetMaxSizeLoadElementValue(_MaxSizeLoadElementValue_);
- filename = InFilename;
- Initialise();
- if ( !OpenFile(exception_on_error))
- return;
- ParseHeader();
- LoadElements();
- CloseFile();
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief
- * @param exception_on_error
- */
-gdcmHeader::gdcmHeader(bool exception_on_error) {
- SetMaxSizeLoadElementValue(_MaxSizeLoadElementValue_);
- Initialise();
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief
- * @param exception_on_error
- * @return
- */
- bool gdcmHeader::OpenFile(bool exception_on_error)
- throw(gdcmFileError) {
- fp=fopen(filename.c_str(),"rb");
- if(exception_on_error) {
- if(!fp)
- throw gdcmFileError("gdcmHeader::gdcmHeader(const char *, bool)");
- }
- if ( fp )
- return true;
- dbg.Verbose(0, "gdcmHeader::gdcmHeader cannot open file", filename.c_str());
- return false;
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief
- * @return TRUE if the close was successfull
- */
-bool gdcmHeader::CloseFile(void) {
- int closed = fclose(fp);
- fp = (FILE *)0;
- if (! closed)
- return false;
- return true;
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief Canonical destructor.
- */
-gdcmHeader::~gdcmHeader (void) {
- dicom_vr = (gdcmVR*)0;
- Dicts = (gdcmDictSet*)0;
- RefPubDict = (gdcmDict*)0;
- RefShaDict = (gdcmDict*)0;
- return;
-}
-
-// Fourth semantics:
-// CMD Command
-// META Meta Information
-// DIR Directory
-// ID
-// PAT Patient
-// ACQ Acquisition
-// REL Related
-// IMG Image
-// SDY Study
-// VIS Visit
-// WAV Waveform
-// PRC
-// DEV Device
-// NMI Nuclear Medicine
-// MED
-// BFS Basic Film Session
-// BFB Basic Film Box
-// BIB Basic Image Box
-// BAB
-// IOB
-// PJ
-// PRINTER
-// RT Radio Therapy
-// DVH
-// SSET
-// RES Results
-// CRV Curve
-// OLY Overlays
-// PXL Pixels
-// DL Delimiters
-//
-
-/**
- * \ingroup gdcmHeader
- * \brief Discover what the swap code is (among little endian, big endian,
- * bad little endian, bad big endian).
- *
- */
-void gdcmHeader::CheckSwap()
-{
- // The only guaranted way of finding the swap code is to find a
- // group tag since we know it's length has to be of four bytes i.e.
- // 0x00000004. Finding the swap code in then straigthforward. Trouble
- // occurs when we can't find such group...
- guint32 s;
- guint32 x=4; // x : for ntohs
- bool net2host; // true when HostByteOrder is the same as NetworkByteOrder
-
- int lgrLue;
- char * entCur;
- char deb[HEADER_LENGTH_TO_READ];
-
- // First, compare HostByteOrder and NetworkByteOrder in order to
- // determine if we shall need to swap bytes (i.e. the Endian type).
- if (x==ntohs(x))
- net2host = true;
- else
- net2host = false;
-
- // The easiest case is the one of a DICOM header, since it possesses a
- // file preamble where it suffice to look for the string "DICM".
- lgrLue = fread(deb, 1, HEADER_LENGTH_TO_READ, fp);
-
- entCur = deb + 128;
- if(memcmp(entCur, "DICM", (size_t)4) == 0) {
- dbg.Verbose(1, "gdcmHeader::CheckSwap:", "looks like DICOM Version3");
- // Next, determine the value representation (VR). Let's skip to the
- // first element (0002, 0000) and check there if we find "UL"
- // - or "OB" if the 1st one is (0002,0001) -,
- // in which case we (almost) know it is explicit VR.
- // WARNING: if it happens to be implicit VR then what we will read
- // is the length of the group. If this ascii representation of this
- // length happens to be "UL" then we shall believe it is explicit VR.
- // FIXME: in order to fix the above warning, we could read the next
- // element value (or a couple of elements values) in order to make
- // sure we are not commiting a big mistake.
- // We need to skip :
- // * the 128 bytes of File Preamble (often padded with zeroes),
- // * the 4 bytes of "DICM" string,
- // * the 4 bytes of the first tag (0002, 0000),or (0002, 0001)
- // i.e. a total of 136 bytes.
- entCur = deb + 136;
- // FIXME
- // Use gdcmHeader::dicom_vr to test all the possibilities
- // instead of just checking for UL, OB and UI !?
- if( (memcmp(entCur, "UL", (size_t)2) == 0) ||
- (memcmp(entCur, "OB", (size_t)2) == 0) ||
- (memcmp(entCur, "UI", (size_t)2) == 0) )
- {
- filetype = ExplicitVR;
- dbg.Verbose(1, "gdcmHeader::CheckSwap:",
- "explicit Value Representation");
- } else {
- filetype = ImplicitVR;
- dbg.Verbose(1, "gdcmHeader::CheckSwap:",
- "not an explicit Value Representation");
- }
- if (net2host) {
- sw = 4321;
- dbg.Verbose(1, "gdcmHeader::CheckSwap:",
- "HostByteOrder != NetworkByteOrder");
- } else {
- sw = 0;
- dbg.Verbose(1, "gdcmHeader::CheckSwap:",
- "HostByteOrder = NetworkByteOrder");
- }
-
- // Position the file position indicator at first tag (i.e.
- // after the file preamble and the "DICM" string).
- rewind(fp);
- fseek (fp, 132L, SEEK_SET);
- return;
- } // End of DicomV3
-
- // Alas, this is not a DicomV3 file and whatever happens there is no file
- // preamble. We can reset the file position indicator to where the data
- // is (i.e. the beginning of the file).
- dbg.Verbose(1, "gdcmHeader::CheckSwap:", "not a DICOM Version3 file");
- rewind(fp);
-
- // Our next best chance would be to be considering a 'clean' ACR/NEMA file.
- // By clean we mean that the length of the first tag is written down.
- // If this is the case and since the length of the first group HAS to be
- // four (bytes), then determining the proper swap code is straightforward.
-
- entCur = deb + 4;
- // We assume the array of char we are considering contains the binary
- // representation of a 32 bits integer. Hence the following dirty
- // trick :
- s = *((guint32 *)(entCur));
-
- switch (s) {
- case 0x00040000 :
- sw = 3412;
- filetype = ACR;
- return;
- case 0x04000000 :
- sw = 4321;
- filetype = ACR;
- return;
- case 0x00000400 :
- sw = 2143;
- filetype = ACR;
- return;
- case 0x00000004 :
- sw = 0;
- filetype = ACR;
- return;
- default :
- dbg.Verbose(0, "gdcmHeader::CheckSwap:",
- "ACR/NEMA unfound swap info (time to raise bets)");
- }
-
- // We are out of luck. It is not a DicomV3 nor a 'clean' ACR/NEMA file.
- // It is time for despaired wild guesses. So, let's assume this file
- // happens to be 'dirty' ACR/NEMA, i.e. the length of the group is
- // not present. Then the only info we have is the net2host one.
- filetype = Unknown;
- if (! net2host )
- sw = 0;
- else
- sw = 4321;
- return;
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief
- */
-void gdcmHeader::SwitchSwapToBigEndian(void) {
- dbg.Verbose(1, "gdcmHeader::SwitchSwapToBigEndian",
- "Switching to BigEndian mode.");
- if ( sw == 0 ) {
- sw = 4321;
- return;
- }
- if ( sw == 4321 ) {
- sw = 0;
- return;
- }
- if ( sw == 3412 ) {
- sw = 2143;
- return;
- }
- if ( sw == 2143 )
- sw = 3412;
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief Find the value representation of the current tag.
- * @param ElVal
- */
-void gdcmHeader::FindVR( gdcmElValue *ElVal) {
- if (filetype != ExplicitVR)
- return;
-
- char VR[3];
- std::string vr;
- int lgrLue;
- char msg[100]; // for sprintf. Sorry
-
- long PositionOnEntry = ftell(fp);
- // Warning: we believe this is explicit VR (Value Representation) because
- // we used a heuristic that found "UL" in the first tag. Alas this
- // doesn't guarantee that all the tags will be in explicit VR. In some
- // cases (see e-film filtered files) one finds implicit VR tags mixed
- // within an explicit VR file. Hence we make sure the present tag
- // is in explicit VR and try to fix things if it happens not to be
- // the case.
- bool RealExplicit = true;
-
- lgrLue=fread (&VR, (size_t)2,(size_t)1, fp);
- VR[2]=0;
- vr = std::string(VR);
-
- // Assume we are reading a falsely explicit VR file i.e. we reached
- // a tag where we expect reading a VR but are in fact we read the
- // first to bytes of the length. Then we will interogate (through find)
- // the dicom_vr dictionary with oddities like "\004\0" which crashes
- // both GCC and VC++ implementations of the STL map. Hence when the
- // expected VR read happens to be non-ascii characters we consider
- // we hit falsely explicit VR tag.
-
- if ( (!isalpha(VR[0])) && (!isalpha(VR[1])) )
- RealExplicit = false;
-
- // CLEANME searching the dicom_vr at each occurence is expensive.
- // PostPone this test in an optional integrity check at the end
- // of parsing or only in debug mode.
- if ( RealExplicit && !dicom_vr->Count(vr) )
- RealExplicit= false;
-
- if ( RealExplicit ) {
- 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;
- }
-
- // We thought this was explicit VR, but we end up with an
- // implicit VR tag. Let's backtrack.
-
- sprintf(msg,"Falsely explicit vr file (%04x,%04x)\n", ElVal->GetGroup(),ElVal->GetElement());
- dbg.Verbose(1, "gdcmHeader::FindVR: ",msg);
-
- fseek(fp, PositionOnEntry, SEEK_SET);
- // When this element is known in the dictionary we shall use, e.g. for
- // the semantics (see the usage of IsAnInteger), the vr proposed by the
- // dictionary entry. Still we have to flag the element as implicit since
- // we know now our assumption on expliciteness is not furfilled.
- // avoid .
- if ( ElVal->IsVrUnknown() )
- ElVal->SetVR("Implicit");
- ElVal->SetImplicitVr();
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief Determines if the Transfer Syntax was already encountered
- * and if it corresponds to a ImplicitVRLittleEndian one.
- *
- * @return True when ImplicitVRLittleEndian found. False in all other cases.
- */
-bool gdcmHeader::IsImplicitVRLittleEndianTransferSyntax(void) {
- gdcmElValue* Element = PubElValSet.GetElementByNumber(0x0002, 0x0010);
- if ( !Element )
- return false;
- LoadElementValueSafe(Element);
- std::string Transfer = Element->GetValue();
- if ( Transfer == "1.2.840.10008.1.2" )
- return true;
- return false;
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief Determines if the Transfer Syntax was already encountered
- * and if it corresponds to a ExplicitVRLittleEndian one.
- *
- * @return True when ExplicitVRLittleEndian found. False in all other cases.
- */
-bool gdcmHeader::IsExplicitVRLittleEndianTransferSyntax(void) {
- gdcmElValue* Element = PubElValSet.GetElementByNumber(0x0002, 0x0010);
- if ( !Element )
- return false;
- LoadElementValueSafe(Element);
- std::string Transfer = Element->GetValue();
- if ( Transfer == "1.2.840.10008.1.2.1" )
- return true;
- return false;
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief Determines if the Transfer Syntax was already encountered
- * and if it corresponds to a DeflatedExplicitVRLittleEndian one.
- *
- * @return True when DeflatedExplicitVRLittleEndian found. False in all other cases.
- */
-bool gdcmHeader::IsDeflatedExplicitVRLittleEndianTransferSyntax(void) {
- gdcmElValue* Element = PubElValSet.GetElementByNumber(0x0002, 0x0010);
- if ( !Element )
- return false;
- LoadElementValueSafe(Element);
- std::string Transfer = Element->GetValue();
- if ( Transfer == "1.2.840.10008.1.2.1.99" )
- return true;
- return false;
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief Determines if the Transfer Syntax was already encountered
- * and if it corresponds to a Explicit VR Big Endian one.
- *
- * @return True when big endian found. False in all other cases.
- */
-bool gdcmHeader::IsExplicitVRBigEndianTransferSyntax(void) {
- gdcmElValue* Element = PubElValSet.GetElementByNumber(0x0002, 0x0010);
- if ( !Element )
- return false;
- LoadElementValueSafe(Element);
- std::string Transfer = Element->GetValue();
- if ( Transfer == "1.2.840.10008.1.2.2" ) //1.2.2 ??? A verifier !
- return true;
- return false;
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief Determines if the Transfer Syntax was already encountered
- * and if it corresponds to a JPEGBaseLineProcess1 one.
- *
- * @return True when JPEGBaseLineProcess1found. False in all other cases.
- */
-bool gdcmHeader::IsJPEGBaseLineProcess1TransferSyntax(void) {
- gdcmElValue* Element = PubElValSet.GetElementByNumber(0x0002, 0x0010);
- if ( !Element )
- return false;
- LoadElementValueSafe(Element);
- std::string Transfer = Element->GetValue();
- if ( Transfer == "1.2.840.10008.1.2.4.50" )
- return true;
- return false;
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief
- *
- * @return
- */
-bool gdcmHeader::IsJPEGLossless(void) {
- gdcmElValue* Element = PubElValSet.GetElementByNumber(0x0002, 0x0010);
- // faire qq chose d'intelligent a la place de ça
- if ( !Element )
- return false;
- LoadElementValueSafe(Element);
- const char * Transfert = Element->GetValue().c_str();
- if ( memcmp(Transfert+strlen(Transfert)-2 ,"70",2)==0) return true;
- if ( memcmp(Transfert+strlen(Transfert)-2 ,"55",2)==0) return true;
- return false;
-}
-
-
-/**
- * \ingroup gdcmHeader
- * \brief Determines if the Transfer Syntax was already encountered
- * and if it corresponds to a JPEGExtendedProcess2-4 one.
- *
- * @return True when JPEGExtendedProcess2-4 found. False in all other cases.
- */
-bool gdcmHeader::IsJPEGExtendedProcess2_4TransferSyntax(void) {
- gdcmElValue* Element = PubElValSet.GetElementByNumber(0x0002, 0x0010);
- if ( !Element )
- return false;
- LoadElementValueSafe(Element);
- std::string Transfer = Element->GetValue();
- if ( Transfer == "1.2.840.10008.1.2.4.51" )
- return true;
- return false;
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief Determines if the Transfer Syntax was already encountered
- * and if it corresponds to a JPEGExtendeProcess3-5 one.
- *
- * @return True when JPEGExtendedProcess3-5 found. False in all other cases.
- */
-bool gdcmHeader::IsJPEGExtendedProcess3_5TransferSyntax(void) {
- gdcmElValue* Element = PubElValSet.GetElementByNumber(0x0002, 0x0010);
- if ( !Element )
- return false;
- LoadElementValueSafe(Element);
- std::string Transfer = Element->GetValue();
- if ( Transfer == "1.2.840.10008.1.2.4.52" )
- return true;
- return false;
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief Determines if the Transfer Syntax was already encountered
- * and if it corresponds to a JPEGSpectralSelectionProcess6-8 one.
- *
- * @return True when JPEGSpectralSelectionProcess6-8 found. False in all
- * other cases.
- */
-bool gdcmHeader::IsJPEGSpectralSelectionProcess6_8TransferSyntax(void) {
- gdcmElValue* Element = PubElValSet.GetElementByNumber(0x0002, 0x0010);
- if ( !Element )
- return false;
- LoadElementValueSafe(Element);
- std::string Transfer = Element->GetValue();
- if ( Transfer == "1.2.840.10008.1.2.4.53" )
- return true;
- return false;
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief Determines if the Transfer Syntax was already encountered
- * and if it corresponds to a RLE Lossless one.
- *
- * @return True when RLE Lossless found. False in all
- * other cases.
- */
-bool gdcmHeader::IsRLELossLessTransferSyntax(void) {
- gdcmElValue* Element = PubElValSet.GetElementByNumber(0x0002, 0x0010);
- if ( !Element )
- return false;
- LoadElementValueSafe(Element);
- std::string Transfer = Element->GetValue();
- if ( Transfer == "1.2.840.10008.1.2.5" )
- return true;
- return false;
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief Determines if the Transfer Syntax was already encountered
- * and if it corresponds to a JPEG200 one.0
- *
- * @return True when JPEG2000 (Lossly or LossLess) found. False in all
- * other cases.
- */
-bool gdcmHeader::IsJPEG2000(void) {
- gdcmElValue* Element = PubElValSet.GetElementByNumber(0x0002, 0x0010);
- if ( !Element )
- return false;
- LoadElementValueSafe(Element);
- std::string Transfer = Element->GetValue();
- if ( (Transfer == "1.2.840.10008.1.2.4.90")
- || (Transfer == "1.2.840.10008.1.2.4.91") )
- return true;
- return false;
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief Predicate for dicom version 3 file.
- * @return True when the file is a dicom version 3.
- */
-bool gdcmHeader::IsDicomV3(void) {
- if ( (filetype == ExplicitVR)
- || (filetype == ImplicitVR) )
- return true;
- return false;
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief When the length of an element value is obviously wrong (because
- * the parser went Jabberwocky) one can hope improving things by
- * applying this heuristic.
- */
-void gdcmHeader::FixFoundLength(gdcmElValue * ElVal, guint32 FoundLength) {
- if ( FoundLength == 0xffffffff)
- FoundLength = 0;
- ElVal->SetLength(FoundLength);
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief
- *
- * @return
- */
- 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();
-
- long l = ftell(fp);
-
- if (errno == 1)
- return 0;
- TotalLength += 4; // We even have to decount the group and element
-
- if ( g != 0xfffe && g!=0xb00c ) /*for bogus header */ {
- char msg[100]; // for sprintf. Sorry
- sprintf(msg,"wrong group (%04x) for an item sequence (%04x,%04x)\n",g, g,n);
- dbg.Verbose(1, "gdcmHeader::FindLengthOB: ",msg);
- long l = ftell(fp);
- errno = 1;
- return 0;
- }
- if ( n == 0xe0dd || ( g==0xb00c && n==0x0eb6 ) ) /* for bogus header */
- FoundSequenceDelimiter = true;
- else if ( n != 0xe000 ){
- char msg[100]; // for sprintf. Sorry
- sprintf(msg,"wrong element (%04x) for an item sequence (%04x,%04x)\n",n, g,n);
- dbg.Verbose(1, "gdcmHeader::FindLengthOB: ",msg);
- errno = 1;
- return 0;
- }
- 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;
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief
- *
- * @return
- */
- void gdcmHeader::FindLength (gdcmElValue * ElVal) {
- guint16 element = ElVal->GetElement();
- guint16 group = ElVal->GetGroup();
- std::string vr = ElVal->GetVR();
- guint16 length16;
- if( (element == 0x0010) && (group == 0x7fe0) ) {
- dbg.SetDebug(0);
- dbg.Verbose(2, "gdcmHeader::FindLength: ",
- "on est sur 7fe0 0010");
- }
-
- if ( (filetype == ExplicitVR) && ! ElVal->IsImplicitVr() ) {
- if ( (vr=="OB") || (vr=="OW") || (vr=="SQ") || (vr=="UN") ) {
-
- // 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;
- }
-
- // Length is encoded on 2 bytes.
- length16 = ReadInt16();
-
- // 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 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
- // encoding, we raise the proper flags. Then we wait for the end
- // of the META group (0x0002) among which is "Transfer Syntax",
- // before switching the swap code to big endian. We have to postpone
- // the switching of the swap code since the META group is fully encoded
- // 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 consists 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
- // encouter 1024 (0x0400) chances are the encoding changed and we
- // found a group with big endian encoding.
- // We shall use this second strategy. In order to make sure that we
- // can interpret the presence of an apparently big endian encoded
- // length of a "Group Length" without committing a big mistake, we
- // add an additional check: we look in the already parsed elements
- // for the presence of a "Transfer Syntax" whose value has to be "big
- // endian encoding". When this is the case, chances are we have got our
- // hands on a big endian encoded file: we switch the swap code to
- // big endian and proceed...
- if ( (element == 0x0000) && (length16 == 0x0400) ) {
- if ( ! IsExplicitVRBigEndianTransferSyntax() ) {
- dbg.Verbose(0, "gdcmHeader::FindLength", "not explicit VR");
- errno = 1;
- return;
- }
- length16 = 4;
- SwitchSwapToBigEndian();
- // Restore the unproperly loaded values i.e. the group, the element
- // and the dictionary entry depending on them.
- guint16 CorrectGroup = SwapShort(ElVal->GetGroup());
- guint16 CorrectElem = SwapShort(ElVal->GetElement());
- gdcmDictEntry * NewTag = GetDictEntryByNumber(CorrectGroup,
- CorrectElem);
- if (!NewTag) {
- // This correct tag is not in the dictionary. Create a new one.
- NewTag = new gdcmDictEntry(CorrectGroup, CorrectElem);
- }
- // FIXME this can create a memory leaks on the old entry that be
- // left unreferenced.
- ElVal->SetDictEntry(NewTag);
- }
-
- // Heuristic: well some files are really ill-formed.
- if ( length16 == 0xffff) {
- length16 = 0;
- dbg.Verbose(0, "gdcmHeader::FindLength",
- "Erroneous element length fixed.");
- }
- FixFoundLength(ElVal, (guint32)length16);
- return;
- }
-
- // 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
- * processor order.
- *
- * @return The suggested integer.
- */
-guint32 gdcmHeader::SwapLong(guint32 a) {
- switch (sw) {
- case 0 :
- break;
- case 4321 :
- a=( ((a<<24) & 0xff000000) | ((a<<8) & 0x00ff0000) |
- ((a>>8) & 0x0000ff00) | ((a>>24) & 0x000000ff) );
- break;
-
- case 3412 :
- a=( ((a<<16) & 0xffff0000) | ((a>>16) & 0x0000ffff) );
- break;
-
- case 2143 :
- a=( ((a<<8) & 0xff00ff00) | ((a>>8) & 0x00ff00ff) );
- break;
- default :
- dbg.Error(" gdcmHeader::SwapLong : unset swap code");
- a=0;
- }
- return(a);
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief Swaps the bytes so they agree with the processor order
- * @return The properly swaped 16 bits integer.
- */
-guint16 gdcmHeader::SwapShort(guint16 a) {
- if ( (sw==4321) || (sw==2143) )
- a =(((a<<8) & 0x0ff00) | ((a>>8)&0x00ff));
- return (a);
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief
- *
- * @return
- */
- void gdcmHeader::SkipBytes(guint32 NBytes) {
- //FIXME don't dump the returned value
- (void)fseek(fp, (long)NBytes, SEEK_CUR);
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief
- * @param ElVal
- * @return
- */
- void gdcmHeader::SkipElementValue(gdcmElValue * ElVal) {
- SkipBytes(ElVal->GetLength());
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief
- * @param NewSize
- * @return
- */
- void gdcmHeader::SetMaxSizeLoadElementValue(long NewSize) {
- if (NewSize < 0)
- return;
- if ((guint32)NewSize >= (guint32)0xffffffff) {
- MaxSizeLoadElementValue = 0xffffffff;
- return;
- }
- MaxSizeLoadElementValue = NewSize;
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief Loads the element content if it's length is not bigger
- * than the value specified with
- * gdcmHeader::SetMaxSizeLoadElementValue()
- */
-void gdcmHeader::LoadElementValue(gdcmElValue * ElVal) {
- size_t item_read;
- guint16 group = ElVal->GetGroup();
- std::string vr = ElVal->GetVR();
- guint32 length = ElVal->GetLength();
- bool SkipLoad = false;
-
- fseek(fp, (long)ElVal->GetOffset(), SEEK_SET);
-
- // FIXME Sequences not treated yet !
- //
- // Ne faudrait-il pas au contraire trouver immediatement
- // une maniere 'propre' de traiter les sequences (vr = SQ)
- // car commencer par les ignorer risque de conduire a qq chose
- // qui pourrait ne pas etre generalisable
- // Well, I'm expecting your code !!!
-
- if( vr == "SQ" )
- SkipLoad = true;
-
- // Heuristic : a sequence "contains" a set of tags (called items). It looks
- // like the last tag of a sequence (the one that terminates the sequence)
- // has a group of 0xfffe (with a dummy length).
- // Well ...
- // Actually (fffe e000) tells us an Element is beginning
- // (fffe e00d) tells us an Element just ended
- // (fffe e0dd) tells us the current SEQuence just ended
-
- if( group == 0xfffe )
- SkipLoad = true;
-
- if ( SkipLoad ) {
- ElVal->SetLength(0);
- ElVal->SetValue("gdcm::Skipped");
- return;
- }
-
- // When the length is zero things are easy:
- if ( length == 0 ) {
- ElVal->SetValue("");
- return;
- }
-
- // The elements whose length is bigger than the specified upper bound
- // are not loaded. Instead we leave a short notice of the offset of
- // the element content and it's length.
- if (length > MaxSizeLoadElementValue) {
- std::ostringstream s;
- s << "gdcm::NotLoaded.";
- s << " Address:" << (long)ElVal->GetOffset();
- s << " 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.
-
- // pour les elements de Value Multiplicity > 1
- // on aura en fait une serie d'entiers
- // on devrait pouvoir faire + compact (?)
-
- if ( IsAnInteger(ElVal) ) {
- guint32 NewInt;
- std::ostringstream s;
- int nbInt;
- if (vr == "US" || vr == "SS") {
- nbInt = length / 2;
- NewInt = ReadInt16();
- s << NewInt;
- if (nbInt > 1) {
- for (int i=1; i < nbInt; i++) {
- s << '\\';
- NewInt = ReadInt16();
- s << NewInt;
- }
- }
-
- } else if (vr == "UL" || vr == "SL") {
- nbInt = length / 4;
- NewInt = ReadInt32();
- s << NewInt;
- if (nbInt > 1) {
- for (int i=1; i < nbInt; i++) {
- s << '\\';
- NewInt = ReadInt32();
- s << NewInt;
- }
- }
- }
- ElVal->SetValue(s.str());
- return;
- }
-
- // We need an additional byte for storing \0 that is not on disk
- char* NewValue = (char*)malloc(length+1);
- if( !NewValue) {
- dbg.Verbose(1, "LoadElementValue: Failed to allocate NewValue");
- return;
- }
- NewValue[length]= 0;
-
- item_read = fread(NewValue, (size_t)length, (size_t)1, fp);
- if ( item_read != 1 ) {
- free(NewValue);
- dbg.Verbose(1, "gdcmHeader::LoadElementValue","unread element value");
- ElVal->SetValue("gdcm::UnRead");
- return;
- }
- ElVal->SetValue(NewValue);
- free(NewValue);
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief Loads the element while preserving the current
- * underlying file position indicator as opposed to
- * to LoadElementValue that modifies it.
- * @param ElVal Element whose value shall be loaded.
- * @return
- */
-void gdcmHeader::LoadElementValueSafe(gdcmElValue * ElVal) {
- long PositionOnEntry = ftell(fp);
- LoadElementValue(ElVal);
- fseek(fp, PositionOnEntry, SEEK_SET);
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief Reads a supposed to be 16 Bits integer
- * \ (swaps it depending on processor endianity)
- *
- * @return integer acts as a boolean
- */
-guint16 gdcmHeader::ReadInt16(void) {
- guint16 g;
- size_t item_read;
- item_read = fread (&g, (size_t)2,(size_t)1, fp);
- if ( item_read != 1 ) {
- // dbg.Verbose(0, "gdcmHeader::ReadInt16", " Failed to read :");
- // if(feof(fp))
- // dbg.Verbose(0, "gdcmHeader::ReadInt16", " End of File encountered");
- if(ferror(fp))
- dbg.Verbose(0, "gdcmHeader::ReadInt16", " File Error");
- errno = 1;
- return 0;
- }
- errno = 0;
- g = SwapShort(g);
- return g;
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief Reads a supposed to be 32 Bits integer
- * \ (swaps it depending on processor endianity)
- *
- * @return
- */
-guint32 gdcmHeader::ReadInt32(void) {
- guint32 g;
- size_t item_read;
- item_read = fread (&g, (size_t)4,(size_t)1, fp);
- if ( item_read != 1 ) {
- //dbg.Verbose(0, "gdcmHeader::ReadInt32", " Failed to read :");
- //if(feof(fp))
- // dbg.Verbose(0, "gdcmHeader::ReadInt32", " End of File encountered");
- if(ferror(fp))
- dbg.Verbose(0, "gdcmHeader::ReadInt32", " File Error");
- errno = 1;
- return 0;
- }
- errno = 0;
- g = SwapLong(g);
- return g;
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief
- *
- * @return
- */
- gdcmElValue* gdcmHeader::GetElValueByNumber(guint16 Group, guint16 Elem) {
-
- gdcmElValue* elValue = PubElValSet.GetElementByNumber(Group, Elem);
- if (!elValue) {
- dbg.Verbose(1, "gdcmHeader::GetElValueByNumber",
- "failed to Locate gdcmElValue");
- return (gdcmElValue*)0;
- }
- return elValue;
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief Build a new Element Value from all the low level arguments.
- * Check for existence of dictionary entry, and build
- * a default one when absent.
- * @param Group group of the underlying DictEntry
- * @param Elem element of the underlying DictEntry
- */
-gdcmElValue* gdcmHeader::NewElValueByNumber(guint16 Group, guint16 Elem) {
- // Find out if the tag we encountered is in the dictionaries:
- gdcmDictEntry * NewTag = GetDictEntryByNumber(Group, Elem);
- if (!NewTag)
- NewTag = new gdcmDictEntry(Group, Elem);
-
- gdcmElValue* NewElVal = new gdcmElValue(NewTag);
- if (!NewElVal) {
- dbg.Verbose(1, "gdcmHeader::NewElValueByNumber",
- "failed to allocate gdcmElValue");
- return (gdcmElValue*)0;
- }
- return NewElVal;
-}
-
-/**
- * \ingroup gdcmHeader
- * \brief TODO
- * @param Value
- * @param Group
- * @param Elem
- * \return integer acts as a boolean
- */
-int gdcmHeader::ReplaceOrCreateByNumber(std::string Value, guint16 Group, guint16 Elem ) {
-
- // TODO : FIXME JPRx
- // curieux, non ?
- // on (je) cree une Elvalue ne contenant pas de valeur
- // on l'ajoute au ElValSet
- // on affecte une valeur a cette ElValue a l'interieur du ElValSet
- // --> devrait pouvoir etre fait + simplement ???
-
- gdcmElValue* nvElValue=NewElValueByNumber(Group, Elem);
- PubElValSet.Add(nvElValue);
- PubElValSet.SetElValueByNumber(Value, Group, Elem);
- return(1);
-}
-
-
-/**
- * \ingroup gdcmHeader
- * \brief Modify or (Creates if not found) an element
- * @param Value new value
- * @param Group
- * @param Elem
- * \return integer acts as a boolean
- *
- */
-int gdcmHeader::ReplaceOrCreateByNumber(char* Value, guint16 Group, guint16 Elem ) {
-
- gdcmElValue* nvElValue=NewElValueByNumber(Group, Elem);
- PubElValSet.Add(nvElValue);
- std::string v = Value;
- PubElValSet.SetElValueByNumber(v, Group, Elem);
- return(1);
-}
-
-
-/**
- * \ingroup gdcmHeader
- * \brief Set a new value if the invoked element exists
- * @param Value
- * @param Group
- * @param Elem
- * \return integer acts as a boolean
- */
-int gdcmHeader::ReplaceIfExistByNumber(char* Value, guint16 Group, guint16 Elem ) {
-
- gdcmElValue* elValue = PubElValSet.GetElementByNumber(Group, Elem);
- std::string v = Value;
- PubElValSet.SetElValueByNumber(v, Group, Elem);
- return 1;
-}