=================================== DCMTK COMPILE TIME FLAGS AND MACROS =================================== The behavior of several DCMTK tools and libraries can be modified by a number of compile time flags (macros), which are explained below. Most of these macros enable experimental or rarely needed features in DCMTK, others disable certain functions. So please, use with care! ALLOW_ILLUMINATION_OVERRIDE Affected: dcmprscu Type of modification: Activates experimental or rarely used feature Explanation: Allows the settings for Illumination and Reflected Ambient Light, which are stored in a Stored Print object, to be overridden from the print job command file. BUGGY_IMPLEMENTATION_CLASS_UID_PREFIX Affected: storescp Type of modification: Activates workaround for known bug in other product Explanation: The dcmnet module contains a workaround that allows to communicate with some buggy Storage SCUs. If the global flag dcmPeerRequiresExactUIDCopy is enabled, an illegal space padding in the Affected SOP Instance UID field of the C-STORE-RQ message is retained in the corresponding C-STORE-RSP message. When this preprocessor macro is defined, it should contain the prefix of an implementation class UID of an implementation known to exhibit the buggy behavior. The workaround is then activated in storescp whenever a Storage SCU with the given implementation class UID root connects. DCMTK_BUILD_DATE Affected: dcmdata Type of modification: Toolkit customization Explanation: When this macro is defined (typically in config/Makefile.def), the given date is used instead of the official DCMTK release data. This allows for example to specify the date of a current development snapshot. DCMTK_BUILD_IN_PROGRESS Affected: all modules Type of modification: Toolkit customization Explanation: When building DLLs, exported symbols must be marked differently if the DLL itself is built or when the DLL shall be used. This macro is defined when the DCMTK gets built and should not be defined when user code that just uses the DCMTK is built. Based on this, the correct annotation gets selected and is used in the code. There should be no valid reasons to define this macro yourself since this is done automatically by the build system. DCMTK_ENABLE_UNSAFE_VSNPRINTF Affected: ofstd Type of modification: Activates feature Explanation: DCMTK requires the snprintf(3)/vsnprintf(3) function, which was introduced with C99 and may not be supported by very old compilers. As a "last resort", an implementation interally using sprintf/vsprintf can be enabled with this macro, which allows the user to compile DCMTK on platforms that do not have the new functions. The implementation allocates a buffer that is 1 kByte larger than the "size" parameter, formats the string into that buffer, and then uses strlcpy() to copy the formatted string into the output buffer, truncating if necessary. This will work in most cases, since few snprintf calls should overrun their buffer by more than 1K, but it can be easily abused by a malicious attacker to cause a buffer overrun. Therefore, this implementation should only be used as a "last resort" and we strongly advise against using it in production code. DCMTK_GUI Affected: all modules Type of modification: Activates experimental or rarely used feature Explanation: When this macro is defined, DCMTK re-assigns the standard output and error streams maintained by ofConsole to string streams. This will allow a GUI based application to extract the messages and either present them to the user or store them in a log file. See comments in ofstd/include/dcmtk/ofstd/ofconsol.h. DICOMDIR_WITHOUT_BACKUP Affected: dcmdata Type of modification: Disables feature Explanation: By default, DCMTK creates a backup of an existing DICOMDIR (using the name DICOMDIR.$$$) when a DcmDicomDir object is written to file. The creation of the backup can be disabled with this macro. DISABLE_COMPRESSION_EXTENSION Affected: dcmqrdb Type of modification: Disables feature Explanation: Disables the support of compression (various transfer syntaxes) in dcmqrdb, a feature which is still experimental. DISABLE_FF_JPEG_BITSTREAM_PADDING Affected: dcmjpeg, dcmjpls Type of modification: Disables feature Explanation: Starting with release 3.6.2, DCMTK pads JPEG and JPEG-LS bitstreams that have odd length with an "extended" end of image (EOI) marker, writing ff/ff/d9 instead of adding a zero byte after the EOI marker, i.e. writing ff/d9/00. The old behaviour can be restored by defining this macro. DISABLE_NAGLE_ALGORITHM Affected: dcmnet Type of modification: Disables feature Explanation: By default, DCMTK does not disable the so-called Nagle algorithm, which allows for improving the efficiency of TCP/IP networks by reducing the number of packets that need to be sent over the network. When compiled with this macro, the Nagle algorithm is disabled for each DICOM transport connection. This was the default in earlier versions of the DCMTK but does not seem to be appropriate anymore for most modern operating systems. The default behavior can be changed by setting the environment variable TCP_NODELAY accordingly (see config/docs/envvars.txt or /usr/local/share/doc/dcmtk/envvars.txt). DISABLE_OFSTD_ATOF Affected: all modules Type of modification: Disables feature Explanation: By default, DCMTK uses its own implementation of atof() to convert strings to double numbers in a locale-independent manner. This flag forces DCMTK to use the standard sscanf() function instead, which is normally much faster and gives a higher precision than DCMTK's built in code, but is locale dependent, i.e. cannot be used with locales such as German since DICOM decimal strings always use the Posix locale. DISABLE_OFSTD_FTOA Affected: all modules Type of modification: Disables feature Explanation: By default, DCMTK uses its own implementation to convert double numbers to strings to in a locale-independent manner. This flag forces DCMTK to use the standard sprintf() function instead, which is locale dependent, i.e. cannot be used with locales such as German since DICOM decimal strings always use the Posix locale. DISABLE_PORT_PERMISSION_CHECK Affected: most/all network server tools Type of modification: Disables feature Explanation: By default, most network server tools (e.g. storescp) check for sufficient privileges to listen on the specified port (if geteuid() is available on the particular system). For examples, on Unix systems listening on port < 1024 usually requires root privileges. However, the port permission check might prevent the tool from being run on such ports on systems with fine-grained permission control (e.g. Linux). Therefore, this check can be disabled using this flag. DISABLE_RECV_TIMEOUT This macro is not supported anymore since the timeout for the recv() function is now configurable at runtime. See global variable dcmSocketReceiveTimeout. DISABLE_SEND_TIMEOUT This macro is not supported anymore since the timeout for the send() function is now configurable at runtime. See global variable dcmSocketSendTimeout. DONT_DISABLE_NAGLE_ALGORITHM This macro is not supported anymore since the Nagle algorithm is no longer disabled by default. See DISABLE_NAGLE_ALGORITHM for details. DONT_LOAD_EXTERNAL_DICTIONARIES This macro is not supported anymore since it has been superseded by macro ENABLE_EXTERNAL_DICTIONARY. See ENABLE_EXTERNAL_DICTIONARY for details. DOXYGEN Affected: everything Type of modification: Hides complexity from Doxygen Explanation: Doxygen is unable to parse some complex statements correctly and it is sometimes sufficient to provide documentation for the basic functionality instead of documenting every detail. This macro is defined when creating the documentation with Doxygen and should NEVER be defined when compiling DCMTK with a C/C++ compiler. NOTE: Doxygen is still unable to expand some macros correctly (e.g. HAVE_WINDOWS_H). Using this macro at the appropriate locations could be a solution for this problem. ENABLE_BUILTIN_DICTIONARY Affected: dcmdata Type of modification: Activates feature Explanation: If enabled, DCMTK's global builtin dictionary, that is always loaded on startup, is populated with known DICOM tags. Otherwise, the builtin dictionary stays empty. For further information about dictionary configuration read dcmdata/docs/datadict.txt. ENABLE_EXTERNAL_DICTIONARY Affected: dcmdata Type of modification: Enables feature Explanation: DCMTK is able to load DICOM data dictionaries from files at application start (before the main function is called). These files are either specified by the DCMDICTPATH environment variable or the default files are used. This flag enables the loading of external dictionaries from file at application start. Disabling it might be useful when only the builtin dictionary should be used. However, if no dictionary gets loaded, this is likely to cause unexpected behavior. Even if this flag is disabled, the reloadDictionaries() method can be used to load the external dictionaries after application start. However, the environment variable DCMDICTPATH has to point to one or more related dictionary files in that case, since if ENABLE_EXTERNAL_DICTIONARY is disabled, no default dictionary path is set within the DCMTK code. On Unix-like systems this flag is enabled by default while on Windows it is disabled. For more information about dictionary configuration read dcmdata/docs/datadict.txt. Note that in former versions of DCMTK a macro called DONT_LOAD_EXTERNAL_DICTIONARIES has been specified which now has been replaced with ENABLE_EXTERNAL_DICTIONARY in order to be consistent with the existing Autoconf and CMake configuration switches. See also entry for DONT_LOAD_EXTERNAL_DICTIONARIES. EXPERIMENTAL_READ_FROM_FILE Affected: dump2dcm Type of modification: Activates experimental or rarely used feature Explanation: When this macro is defined, the relatively new function createValueFromTempFile() is used for reading large binary data files. LOCK_IMAGE_FILES Affected: dcmpstat, dcmqrdb Type of modification: Activates experimental or rarely used feature Explanation: When this macro is defined, the DICOM image file to be send or received/created is locked exclusively. LOG4CPLUS_DISABLE_xxx (where xxx is one of TRACE, DEBUG, INFO, WARN, ERROR and FATAL) Affected: oflog Type of modification: Disables feature Explanation: When one of these macros is defined all log message of this type and lower are disabled and optimized away. NO_GET_SUPPORT Affected: dcmqrdb Type of modification: Disables feature Explanation: Disables the experimental C-GET support in dcmqrdb. NO_PATIENTSTUDYONLY_SUPPORT Affected: dcmqrdb Type of modification: Disables feature Explanation: Disables support for the Patient/Study Only Query/Retrieve Model in dcmqrdb. OFCONDITION_IMPLICIT_BOOL_CONVERSION Affected: ofstd Type of modification: Activates experimental or rarely used feature Explanation: Activates an implicit conversion from OFCondition to OFBool, i.e. operator OFBool(). Implicit conversion might not always be a good idea since it can hide unwanted constructs. Therefore, this operator is disabled by default. ON_THE_FLY_COMPRESSION Affected: storescu Type of modification: Activates experimental or rarely used feature Explanation: When this macro is defined, the storescu tries to compress or decompress the DICOM image to be sent (if required) depending on the negotiated transfer syntax. OLD_USER_INFO_SUB_ITEM_ORDER Affected: dcmnet Type of modification: Activates experimental or rarely used feature Explanation: Prior DCMTK releases did not encode A-ASSOCIATE user information sub-items in ascending order, i.e. they sent 55H followed by 54H and 56H. This behavior has been "legalized" by DICOM CP 280 but is known to create problems with some other toolkits. The current DCMTK release always sends the user information sub-items in ascending order, but can be "forced" with this macro to revert to the old behavior. It should be re-activated for testing purposes only. PASTEL_COLOR_OUTPUT Affected: dcmimgle, dcmimage Type of modification: Activates experimental or rarely used feature Explanation: Activates experimental code in dcmimgle/dcmimage that renders monochrome images with pastel colors. PDV_TEST Affected: dcmnet Type of modification: Activates experimental or rarely used feature Explanation: Causes the network module to insert a false, zero-length PDV (2 byte header) into each P-DATA-PDU. PIXELSTACK_MEMORY_LEAK_WORKAROUND Affected: dcmdata Type of modification: Activates experimental or rarely used feature Explanation: On certain platforms there seems to be a memory leak in DcmDataset::chooseRepresentation(). The work-around activated by this macro should solve this issue. PRINT_REPLACED_DICTIONARY_ENTRIES Affected: dcmdata Type of modification: Activates experimental or rarely used feature Explanation: When reading the data dictionary, duplicate entries (i.e. entries replacing an older entry in the dictionary) are reported on console if compiled with this macro. Useful for testing a new dictionary version. REJECT_FILE_IF_META_GROUP_LENGTH_ABSENT Affected: dcmdata Type of modification: Disables feature Explanation: When reading the a file that contains an incorrect meta header where meta header group length (0002,0000) is absent, DCMTK since release 3.5.4 nevertheless tries to parse the file, unless this macro is enabled, in which case the behavior up to DCMTK 3.5.3 is retained. RETAIN_ASSOCIATION Affected: dcmqrti Type of modification: Activates experimental or rarely used feature Explanation: Keeps association to remote Query SCP open after study/series/image listing. Default behavior is to open new association for each query. REVERSE_OVERLAY_ORIGIN_ORDER Affected: dcmimgle Type of modification: Activates experimental or rarely used feature Explanation: When compiled with this macro, dcmimgle assumes that the values in DCM_ImageFrameOrigin are in reverse order, i.e. X\Y instead of Y\X. SITE_UID_ROOT Affected: dcmdata Type of modification: Site customization Explanation: dcmdata contains a routine that generates DICOM unique identifiers (UIDs). By default, these are constructed from the OFFIS UID namespace, i.e. using the OFFIS UID Root "1.2.276.0.7230010.3". Users who prefer to let the toolkit generate UIDs from their own UID namespace should compile DCMTK with SITE_UID_ROOT defined to their own UID root. Please make sure that the resulting UIDs do not exceed the 64 characters limit! STARVIEW Affected: dcmimgle, dcmimage Type of modification: Activates experimental or rarely used feature Explanation: Enables support for old StarView 2 GUI class library from Star Division. SUPPRESS_CREATE_STAMP Affected: dcmdata Type of modification: Activates experimental or rarely used feature Explanation: When defined, suppresses the creation of a time stamp comment when re-generating dcdeftag.h and dcdictbi.cc. USE__LOCKING Affected: dcmnet Type of modification: Activates alternative implementation Explanation: Activates an alternative emulation of flock() on Win32 platforms using _locking(). This version should only be used on compilers where _get_osfhandle() is not available since it does not implement shared locks. USE_BINARY_MODE_FOR_STDOUT_ON_WINDOWS Affected: dcmdata Type of modification: Activates experimental or rarely used feature Explanation: On Windows systems, the standard output (stdout) is opened in text mode by default. Therefore, the binary output of tools like dcm2pnm to stdout does not work correctly (in contrast to Unix systems). When this preprocessor macro is defined, the binary mode is enabled for stdout. However, this causes newlines in the textual output to be converted to LF only (instead of CR LF which would be the usual translation for Windows). USE_NULL_SAFE_OFSTRING Affected: ofstd Type of modification: Activates feature Explanation: When this macro is defined, OFString(NULL) results in an empty string. If this macro is not defined, OFString(NULL) causes a NULL pointer dereference. This macro has no effect when HAVE_STL_STRING is also defined. Currently, this macro is always defined by DCMTK's Makefiles. This will change in future releases. USE_WIN32_CREATE_MUTEX Affected: ofstd Type of modification: Activates alternative implementation Explanation: Starting with DCMTK 3.6.2, the Win32 version of the OFMutex class uses critical sections instead of Win32 mutexes, because critical sections are much faster. Their only drawback is that they cannot be shared across processes. Users who want to revert to the behavior of older DCMTK releases can define this macro. USE_WIN32_READ_WRITE_LOCK_HELPER Affected: ofstd Type of modification: Re-activated behavior of earlier DCMTK releases Explanation: Starting with DCMTK 3.6.4, the Win32 version of the OFReadWriteLock class uses Slim Reader/Writer (SRW) Locks, which are available since Windows Vista, instead of the older implementation based on a Mutex, a Semaphore and a counter, because SRW locks are much faster. Users who want to revert to the behavior of older DCMTK releases can define this macro. USING_STD_NAMESPACE Affected: all modules Type of modification: Re-activated behavior of earlier DCMTK releases Explanation: DCMTK by default does not anymore pollute the default namespace by importing namespace std. Earlier releases did this to simplify compatibility with older compilers where STL classes were not consistently defined in namespace std. We now have configure macros which should care for this. If user code still relies on namespace std to be included, compile with this macro defined. WIDE_CHAR_FILE_IO_FUNCTIONS Affected: ofstd Type of modification: Activates feature Explanation: In addition to the standard file I/O functions, the OFFile class also defines the corresponding wide character functions from C99 standard. Since these functions are not yet supported by all compilers and the current implementation is Windows-specific, this feature is disabled by default. When using CMake, you can enable this macro by setting the CMake option DCMTK_WIDE_CHAR_FILE_IO_FUNCTIONS to "on". WIDE_CHAR_MAIN_FUNCTION Affected: currently not used Type of modification: Activates experimental or rarely used feature Explanation: On Windows (at least for MSVC), a different main function has to be used in order to get the command line arguments with wide character encoding (UTF-16). By defining this flag, the macro DCMTK_MAIN_FUNCTION expands to wmain() instead of main(). When using CMake, you can enable this macro by setting the CMake option DCMTK_WIDE_CHAR_MAIN_FUNCTION to "on". Usually, WIDE_CHAR_FILE_IO_FUNCTIONS should also be enabled. WRITE_VERY_LARGE_CHUNKS Affected: dcmdata Type of modification: Re-activated behavior of earlier DCMTK releases Explanation: On Windows (at least for some versions of MSVC), calls to fwrite() for more than 67,076,095 bytes (a bit less than 64 MByte) fail if we're writing to a network share. See MSDN KB899149. As a workaround, we always write in chunks of 32M which should hardly negatively affect performance. This macro enables the behavior of earlier DCMTK releases, i.e. to always call fwrite with as much data as possible, which is known not to work correctly on Win32 but might offer very minor performance benefits on other platforms. ZLIB_ENCODE_RFC1950_HEADER Affected: dcmdata Type of modification: Activates experimental or rarely used feature Explanation: When this macro is defined, the deflated ZLIB format is created instead of the deflated bitstream format (i.e. RFC 1950 instead of RFC 1951). Please note that the resulting bitstream is not DICOM compliant. So, use only for testing, and use with care!