DCMTK Version 3.7.0 OFFIS DICOM Toolkit

dcmdecap: Extract encapsulated file from DICOM encapsulated storage object

# SYNOPSIS

    dcmdecap [options] dcmfile-in encfile-out

# DESCRIPTION

The dcmdecap utility reads a DICOM file of one of the Encapsulated Storage SOP Classes (dcmfile-in), extracts the embedded document and writes it to an output file (encfile-out). Optionally a command can be executed after the creation of the output file.

# PARAMETERS

    dcmfile-in   DICOM input filename ("-" for stdin)

    encfile-out  Encapsulated document output filename ("-" for stdout)

# OPTIONS

## general options

      -h   --help
             print this help text and exit

           --version
             print version information and exit

           --arguments
             print expanded command line arguments

      -q   --quiet
             quiet mode, print no warnings and errors

      -v   --verbose
             verbose mode, print processing details

      -d   --debug
             debug mode, print debug information

      -ll  --log-level  [l]evel: string constant
             (fatal, error, warn, info, debug, trace)
             use level l for the logger

      -lc  --log-config  [f]ilename: string
             use config file f for the logger

## input options

    input file format:

      +f   --read-file
             read file format or data set (default)

      +fo  --read-file-only
             read file format only

      -f   --read-dataset
             read data set without file meta information

    input transfer syntax:

      -t=  --read-xfer-auto
             use TS recognition (default)

      -td  --read-xfer-detect
             ignore TS specified in the file meta header

      -te  --read-xfer-little
             read with explicit VR little endian TS

      -tb  --read-xfer-big
             read with explicit VR big endian TS

      -ti  --read-xfer-implicit
             read with implicit VR little endian TS

    parsing of odd-length attributes:

      +ao  --accept-odd-length
             accept odd length attributes (default)

      +ae  --assume-even-length
             assume real length is one byte larger

    handling of undefined length UN elements:

      +ui  --enable-cp246
             read undefined len UN as implicit VR (default)

      -ui  --disable-cp246
             read undefined len UN as explicit VR

    handling of defined length UN elements:

      -uc  --retain-un
             retain elements as UN (default)

      +uc  --convert-un
             convert to real VR if known

    automatic data correction:

      +dc  --enable-correction
             enable automatic data correction (default)

      -dc  --disable-correction
             disable automatic data correction

    bitstream format of deflated input:

      +bd  --bitstream-deflated
             expect deflated bitstream (default)

      +bz  --bitstream-zlib
             expect deflated zlib bitstream

## processing options

execution options:

      -x   --exec  [c]ommand: string
             execute command c after document extraction

# NOTES

Option –exec allows for the execution of a certain command line after the creation of the PDF document. The command line to be executed is passed to this option as a parameter. The specified command line may contain the placeholder '#f', which will be replaced by the output filename at run time. The specified command line is executed in the foreground, i.e. dcmdecap will be blocked until the command terminates.

# LOGGING

The level of logging output of the various command line tools and underlying libraries can be specified by the user. By default, only errors and warnings are written to the standard error stream. Using option –verbose also informational messages like processing details are reported. Option –debug can be used to get more details on the internal activity, e.g. for debugging purposes. Other logging levels can be selected using option –log-level. In –quiet mode only fatal errors are reported. In such very severe error events, the application will usually terminate. For more details on the different logging levels, see documentation of module "oflog".

In case the logging output should be written to file (optionally with logfile rotation), to syslog (Unix) or the event log (Windows) option –log-config can be used. This configuration file also allows for directing only certain messages to a particular output stream and for filtering certain messages based on the module or application where they are generated. An example configuration file is provided in <etcdir>/logger.cfg.

# EXIT CODES

The dcmdecap utility uses the following exit codes when terminating. This enables the user to check for the reason why the application terminated.

## general

    EXITCODE_NO_ERROR                         0
    EXITCODE_COMMANDLINE_SYNTAX_ERROR         1

## input file errors

    EXITCODE_CANNOT_READ_INPUT_FILE          20
    EXITCODE_NO_INPUT_FILES                  21
    EXITCODE_INVALID_INPUT_FILE              22

## output file errors

    EXITCODE_CANNOT_WRITE_OUTPUT_FILE        40

## processing errors

    EXITCODE_EXEC_FAILED                     91

# COMMAND LINE

All command line tools use the following notation for parameters: square brackets enclose optional values (0-1), three trailing dots indicate that multiple values are allowed (1-n), a combination of both means 0 to n values.

Command line options are distinguished from parameters by a leading '+' or '-' sign, respectively. Usually, order and position of command line options are arbitrary (i.e. they can appear anywhere). However, if options are mutually exclusive the rightmost appearance is used. This behavior conforms to the standard evaluation rules of common Unix shells.

In addition, one or more command files can be specified using an '@' sign as a prefix to the filename (e.g. @command.txt). Such a command argument is replaced by the content of the corresponding text file (multiple whitespaces are treated as a single separator unless they appear between two quotation marks) prior to any further evaluation. Please note that a command file cannot contain another command file. This simple but effective approach allows one to summarize common combinations of options/parameters and avoids longish and confusing command lines (an example is provided in file <datadir>/dumppat.txt).

# ENVIRONMENT

The dcmdecap utility will attempt to load DICOM data dictionaries specified in the DCMDICTPATH environment variable. By default, i.e. if the DCMDICTPATH environment variable is not set, the file <datadir>/dicom.dic will be loaded unless the dictionary is built into the application (default for Windows).

The default behavior should be preferred and the DCMDICTPATH environment variable only used when alternative data dictionaries are required. The DCMDICTPATH environment variable has the same format as the Unix shell PATH variable in that a colon (":") separates entries. On Windows systems, a semicolon (";") is used as a separator. The data dictionary code will attempt to load each file specified in the DCMDICTPATH environment variable. It is an error if no data dictionary can be loaded.

# SEE ALSO

dcmencap(1)

# COPYRIGHT

Copyright (C) 2007-2025 by OFFIS e.V., Escherweg 2, 26121 Oldenburg, Germany.

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