DcmCodecList Class Reference

singleton that keeps list of registered codecs for dcmdata. More...

Public Member Functions
virtual	~DcmCodecList ()
	destructor

Static Public Member Functions
static OFCondition	registerCodec (const DcmCodec *aCodec, const DcmRepresentationParameter *aDefaultRepParam, const DcmCodecParameter *aCodecParameter)
	registers a codec object in the global list of codecs consulted by dcmdata whenever conversion to/from compressed transfer syntaxes is requested. More...
static OFCondition	deregisterCodec (const DcmCodec *aCodec)
	deregisters a codec and it's parameter objects from the global list. More...
static OFCondition	updateCodecParameter (const DcmCodec *aCodec, const DcmCodecParameter *aCodecParameter)
	updates the codec parameters object for a codec that has been registered before. More...
static OFCondition	decode (const DcmXfer &fromType, const DcmRepresentationParameter *fromParam, DcmPixelSequence *fromPixSeq, DcmPolymorphOBOW &uncompressedPixelData, DcmStack &pixelStack)
	looks for a codec that is able to decode from the given transfer syntax and calls the decode() method of the codec. More...
static OFCondition	decodeFrame (const DcmXfer &fromType, const DcmRepresentationParameter *fromParam, DcmPixelSequence *fromPixSeq, DcmItem *dataset, Uint32 frameNo, Uint32 &startFragment, void *buffer, Uint32 bufSize, OFString &decompressedColorModel)
	looks for a codec that is able to decode from the given transfer syntax and calls the decodeFrame() method of the codec. More...
static OFCondition	encode (const E_TransferSyntax fromRepType, const Uint16 *pixelData, const Uint32 length, const E_TransferSyntax toRepType, const DcmRepresentationParameter *toRepParam, DcmPixelSequence *&pixSeq, DcmStack &pixelStack)
	looks for a codec that is able to encode from the given transfer syntax and calls the encode() method of the codec. More...
static OFCondition	encode (const E_TransferSyntax fromRepType, const DcmRepresentationParameter *fromParam, DcmPixelSequence *fromPixSeq, const E_TransferSyntax toRepType, const DcmRepresentationParameter *toRepParam, DcmPixelSequence *&toPixSeq, DcmStack &pixelStack)
	looks for a codec that is able to transcode (re-compresses) from the given transfer syntax to the given transfer syntax and calls the encode() method of the codec. More...
static OFBool	canChangeCoding (const E_TransferSyntax fromRepType, const E_TransferSyntax toRepType)
	looks for a codec that claims to be able to convert between the given transfer syntaxes. More...
static OFCondition	determineDecompressedColorModel (const DcmXfer &fromType, const DcmRepresentationParameter *fromParam, DcmPixelSequence *fromPixSeq, DcmItem *dataset, OFString &decompressedColorModel)
	determine color model of the decompressed image More...

Private Member Functions
	DcmCodecList (const DcmCodec *aCodec, const DcmRepresentationParameter *aDefaultRepParam, const DcmCodecParameter *aCodecParameter)
	constructor More...
	DcmCodecList (const DcmCodecList &)
	private undefined copy constructor
DcmCodecList &	operator= (const DcmCodecList &)
	private undefined copy assignment operator

Private Attributes
const DcmCodec *	codec
	pointer to codec object
const DcmRepresentationParameter *	defaultRepParam
	pointer to default representation parameter
const DcmCodecParameter *	codecParameter
	pointer to codec parameter set

Static Private Attributes
static OFList< DcmCodecList * >	registeredCodecs
	singleton list of registered codecs
static OFReadWriteLock	codecLock
	read/write lock guarding access to singleton list

Detailed Description

singleton that keeps list of registered codecs for dcmdata.

All operations on the list are protected by a read/write lock and, therefore, are safe for multi-thread applications.

Constructor & Destructor Documentation

DcmCodecList::DcmCodecList ( const DcmCodec *  aCodec, const DcmRepresentationParameter *  aDefaultRepParam, const DcmCodecParameter *  aCodecParameter  )

private

constructor

Parameters

aCodec	pointer to codec object.
aDefaultRepParam	default representation parameter.
aCodecParameter	codec parameter.

Member Function Documentation

static OFBool DcmCodecList::canChangeCoding ( const E_TransferSyntax  fromRepType, const E_TransferSyntax  toRepType  )

static

looks for a codec that claims to be able to convert between the given transfer syntaxes.

A read lock on the list of codecs is acquired until this method returns.

Parameters

fromRepType	current transfer syntax
toRepType	desired new transfer syntax

Returns

true if transformation is supported by a codec, false otherwise.

static OFCondition DcmCodecList::decode ( const DcmXfer &  fromType, const DcmRepresentationParameter *  fromParam, DcmPixelSequence *  fromPixSeq, DcmPolymorphOBOW &  uncompressedPixelData, DcmStack &  pixelStack  )

static

looks for a codec that is able to decode from the given transfer syntax and calls the decode() method of the codec.

A read lock on the list of codecs is acquired until this method returns.

Parameters

fromType	transfer syntax to decode from
fromParam	representation parameter of current compressed representation, may be NULL.
fromPixSeq	compressed pixel sequence
uncompressedPixelData	uncompressed pixel data stored in this element
pixelStack	stack pointing to the location of the pixel data element in the current dataset.

Returns

EC_Normal if successful, an error code otherwise.

static OFCondition DcmCodecList::decodeFrame ( const DcmXfer &  fromType, const DcmRepresentationParameter *  fromParam, DcmPixelSequence *  fromPixSeq, DcmItem *  dataset, Uint32  frameNo, Uint32 &  startFragment, void *  buffer, Uint32  bufSize, OFString &  decompressedColorModel  )

static

looks for a codec that is able to decode from the given transfer syntax and calls the decodeFrame() method of the codec.

A read lock on the list of codecs is acquired until this method returns.

Parameters

fromType	transfer syntax to decode from
fromParam	representation parameter of current compressed representation, may be NULL.
fromPixSeq	compressed pixel sequence
dataset	pointer to dataset in which pixel data element is contained
frameNo	number of frame, starting with 0 for the first frame
startFragment	index of the compressed fragment that contains all or the first part of the compressed bitstream for the given frameNo. Upon successful return this parameter is updated to contain the index of the first compressed fragment of the next frame. When unknown, zero should be passed. In this case the decompression algorithm will try to determine the index by itself, which will always work if frames are decompressed in increasing order from first to last, but may fail if frames are decompressed in random order, multiple fragments per frame and multiple frames are present in the dataset, and the offset table is empty.
buffer	pointer to buffer where frame is to be stored
bufSize	size of buffer in bytes
decompressedColorModel	upon successful return, the color model of the decompressed image (which may be different from the one used in the compressed images) is returned in this parameter.

Returns

EC_Normal if successful, an error code otherwise.

static OFCondition DcmCodecList::deregisterCodec ( const DcmCodec *  aCodec )

static

deregisters a codec and it's parameter objects from the global list.

This call is safe in multi-thread operations.

Parameters

aCodec

pointer to registered codec

Returns

EC_Normal if successful, an error code otherwise

static OFCondition DcmCodecList::determineDecompressedColorModel ( const DcmXfer &  fromType, const DcmRepresentationParameter *  fromParam, DcmPixelSequence *  fromPixSeq, DcmItem *  dataset, OFString &  decompressedColorModel  )

static

determine color model of the decompressed image

Parameters

fromType	transfer syntax to decode from
fromParam	representation parameter of current compressed representation, may be NULL
fromPixSeq	compressed pixel sequence
dataset	pointer to dataset in which pixel data element is contained
decompressedColorModel	upon successful return, the color model of the decompressed image (which may be different from the one used in the compressed images) is returned in this parameter

Returns

EC_Normal if successful, an error code otherwise

static OFCondition DcmCodecList::encode ( const E_TransferSyntax  fromRepType, const Uint16 *  pixelData, const Uint32  length, const E_TransferSyntax  toRepType, const DcmRepresentationParameter *  toRepParam, DcmPixelSequence *&  pixSeq, DcmStack &  pixelStack  )

static

looks for a codec that is able to encode from the given transfer syntax and calls the encode() method of the codec.

A read lock on the list of codecs is acquired until this method returns.

Parameters

fromRepType	transfer syntax to encode from
pixelData	pointer to the uncompressed image data in OW format and local byte order
length	of the pixel data field in bytes
toRepType	transfer syntax to compress to
toRepParam	representation parameter describing the desired compressed representation (e.g. JPEG quality)
pixSeq	compressed pixel sequence (pointer to new DcmPixelSequence object allocated on heap) returned in this parameter upon success.
pixelStack	stack pointing to the location of the pixel data element in the current dataset.

Returns

EC_Normal if successful, an error code otherwise.

static OFCondition DcmCodecList::encode ( const E_TransferSyntax  fromRepType, const DcmRepresentationParameter *  fromParam, DcmPixelSequence *  fromPixSeq, const E_TransferSyntax  toRepType, const DcmRepresentationParameter *  toRepParam, DcmPixelSequence *&  toPixSeq, DcmStack &  pixelStack  )

static

looks for a codec that is able to transcode (re-compresses) from the given transfer syntax to the given transfer syntax and calls the encode() method of the codec.

A read lock on the list of codecs is acquired until this method returns.

Parameters

fromRepType	current transfer syntax of the compressed image
fromParam	current representation parameter of compressed data, may be NULL
fromPixSeq	compressed pixel sequence
toRepType	transfer syntax to compress to
toRepParam	representation parameter describing the desired new compressed representation (e.g. JPEG quality)
toPixSeq	compressed pixel sequence (pointer to new DcmPixelSequence object allocated on heap) returned in this parameter upon success.
pixelStack	stack pointing to the location of the pixel data element in the current dataset.

Returns

EC_Normal if successful, an error code otherwise.

static OFCondition DcmCodecList::registerCodec ( const DcmCodec *  aCodec, const DcmRepresentationParameter *  aDefaultRepParam, const DcmCodecParameter *  aCodecParameter  )

static

registers a codec object in the global list of codecs consulted by dcmdata whenever conversion to/from compressed transfer syntaxes is requested.

This function must not be called before main() is started, e.g. from a constructor of a global object. This call is safe in multi-thread operations.

Parameters

aCodec	pointer to codec object. Must remain unmodified and valid until the codec has been deregistered.
aDefaultRepParam	default representation parameter. Must remain unmodified and valid until the codec has been deregistered.
aCodecParameter	codec parameter. Must remain unmodified and valid until the codec has been deregistered or the parameter has been replaced by a call to updateCodecParameter()

Returns

EC_Normal if successful, an error code otherwise

static OFCondition DcmCodecList::updateCodecParameter ( const DcmCodec *  aCodec, const DcmCodecParameter *  aCodecParameter  )

static

updates the codec parameters object for a codec that has been registered before.

This call is safe in multi-thread operations.

Parameters

aCodec	pointer to codec object that has been registered before
aCodecParameter	codec parameter. Must remain unmodified and valid until the codec has been deregistered or the parameter has been replaced by another call to updateCodecParameter()

Returns

EC_Normal if successful, an error code otherwise

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The documentation for this class was generated from the following file:

• dcmdata/include/dcmtk/dcmdata/dccodec.h