Representation of a MPEG PSI/SI descriptors in binary format. More...

#include <tsDescriptor.h>

Inheritance diagram for ts::Descriptor:

Collaboration diagram for ts::Descriptor:

Public Types
using	SuperClass = DataBlock< 8, 8 >
	Explicit reference to superclass.

Public Member Functions
	Descriptor ()=default
	Default constructor.

	Descriptor (const ByteBlock &bb)
	Constructor from full binary content.

	Descriptor (const ByteBlockPtr &bb, ShareMode mode)
	Constructor from full binary content.

	Descriptor (const Descriptor &desc, ShareMode mode)
	Copy constructor.

	Descriptor (const void *data, size_t size)
	Constructor from full binary content.

	Descriptor (Descriptor &&desc) noexcept
	Move constructor.

	Descriptor (DID tag, const ByteBlock &data)
	Constructor from tag and payload.

	Descriptor (DID tag, const void *data, size_t size)
	Constructor from tag and payload.

virtual	~Descriptor () override
	Virtual destructor.

virtual void	clear ()
	Clear data content.

virtual const uint8_t *	content () const
	Access to the full binary content of the data.

DataBlock &	copy (const DataBlock &other)
	Duplication.

AbstractDescriptorPtr	deserialize (DuckContext &duck, DescriptorContext &context) const
	Deserialize the descriptor.

AbstractDescriptorPtr	deserialize (DuckContext &duck, EDID edid) const
	Deserialize the descriptor.

bool	fromXML (DuckContext &duck, const xml::Element *node, TID tid=TID_NULL)
	This method converts an XML node as a binary descriptor.

bool	fromXML (DuckContext &duck, EDID &edid, const xml::Element *node, TID tid=TID_NULL)
	This method converts an XML node as a binary descriptor.

void	invalidate ()
	Invalidate descriptor content.

virtual bool	isValid () const
	Check if the data structure has valid content.

bool	matchContent (const ByteBlock &pattern, const ByteBlock &mask=ByteBlock()) const
	Check if the start of the data matches a given pattern.

bool	operator== (const DataBlock &other) const
	Equality operator.

bool	operator== (const Descriptor &other) const
	Comparison operator.

uint8_t *	payload ()
	Access to the payload of the descriptor.

const uint8_t *	payload () const
	Access to the payload of the descriptor.

size_t	payloadSize () const
	Size of the payload of the descriptor.

size_t	rawDataSize () const
	Size of the complete binary raw data containing the logical structure.

void	reload (const ByteBlock &content)
	Reload from full binary content.

void	reload (const ByteBlockPtr &content_ptr)
	Reload from full binary content.

void	reload (const void *content, size_t content_size)
	Reload from full binary content.

void	replacePayload (const ByteBlock &payload)
	Replace the payload of the descriptor.

void	replacePayload (const void *data, size_t size)
	Replace the payload of the descriptor.

void	resizePayload (size_t size)
	Resize (truncate or extend) the payload of the descriptor.

virtual size_t	size () const
	Size of the logical binary content of the data.

DID	tag () const
	Get the descriptor tag.

xml::Element *	toXML (DuckContext &duck, xml::Element *parent, DescriptorContext &context, bool force_generic=false) const
	This method converts a descriptor to XML.

XDID	xdid () const
	Get the extension descriptor id.

Static Public Member Functions
static size_t	GetLengthField (const void *content, size_t content_size)
	Static method to extract the content of the length field.

static bool	ValidateLengthField (const void *content, size_t content_size, bool allow_extra_data)
	Static method to validate the content of the length field.

Static Public Attributes
static constexpr size_t	AFTER_LEN_BYTE_OFFSET
	Offset in bytes of the next byte after the length field.

static constexpr size_t	LEN_BIT_OFFSET
	Offset in bits of the length field from the beginning of the structure.

static constexpr size_t	LEN_BIT_SIZE
	Size in bits of the length field.

static constexpr bool	UNBOUNDED_IS_ALLOWED
	If true, the length field allows zero as an "unbounded" value.

Protected Member Functions
void	rwAppend (const void *data, size_t dsize)
	Append raw data to the full binary content of the data for subclasses.

uint8_t *	rwContent ()
	Read/write access to the full binary content of the data for subclasses.

void	rwResize (size_t s)
	Resize the full binary content of the data for subclasses.

Detailed Description

Representation of a MPEG PSI/SI descriptors in binary format.

Constructor & Destructor Documentation

◆ Descriptor() [1/7]

ts::Descriptor::Descriptor	(	const Descriptor &	desc,
		ShareMode	mode
	)

inline

Copy constructor.

Parameters

[in]	desc	Another instance to copy.
[in]	mode	The descriptors' data are either shared (ShareMode::SHARE) between the two descriptors or duplicated (ShareMode::COPY).

◆ Descriptor() [2/7]

ts::Descriptor::Descriptor ( Descriptor && desc )

inlinenoexcept

Move constructor.

Parameters

[in,out] desc Another instance to move.

◆ Descriptor() [3/7]

ts::Descriptor::Descriptor	(	DID	tag,
		const void *	data,
		size_t	size
	)

Constructor from tag and payload.

The content is copied into the section if valid.

Parameters

[in]	tag	Descriptor tag.
[in]	data	Address of the descriptor payload.
[in]	size	Size in bytes of the descriptor payload.

◆ Descriptor() [4/7]

ts::Descriptor::Descriptor	(	DID	tag,
		const ByteBlock &	data
	)

Constructor from tag and payload.

The content is copied into the section if valid.

Parameters

[in]	tag	Descriptor tag.
[in]	data	Descriptor payload.

◆ Descriptor() [5/7]

ts::Descriptor::Descriptor	(	const void *	data,
		size_t	size
	)

inline

Constructor from full binary content.

The content is copied into the section if valid.

Parameters

[in]	data	Address of the descriptor data.
[in]	size	Size in bytes of the descriptor data.

◆ Descriptor() [6/7]

ts::Descriptor::Descriptor ( const ByteBlock & bb )

inline

Constructor from full binary content.

The content is copied into the section if valid.

Parameters

[in] bb Descriptor binary data.

◆ Descriptor() [7/7]

ts::Descriptor::Descriptor	(	const ByteBlockPtr &	bb,
		ShareMode	mode
	)

inline

Constructor from full binary content.

Parameters

[in]	bb	Descriptor binary data.
[in]	mode	The data are either shared (ShareMode::SHARE) between the descriptor and bb or duplicated (ShareMode::COPY).

Member Function Documentation

◆ tag()

DID ts::Descriptor::tag ( ) const

inline

Get the descriptor tag.

Returns: The descriptor tag or the reserved value 0 if the descriptor is invalid.

◆ xdid()

XDID ts::Descriptor::xdid ( ) const

Get the extension descriptor id.

Returns: The extension descriptor id. For MPEG or DVB extension descriptors, this is a combination of the descriptor tag and the extension tag. For other descriptors, this is the descriptor tag only.

◆ payload() [1/2]

const uint8_t * ts::Descriptor::payload ( ) const

inline

Access to the payload of the descriptor.

Returns: Address of the payload of the descriptor.

◆ payload() [2/2]

uint8_t * ts::Descriptor::payload ( )

inline

Access to the payload of the descriptor.

Returns: Address of the payload of the descriptor.

◆ payloadSize()

size_t ts::Descriptor::payloadSize ( ) const

inline

Size of the payload of the descriptor.

Returns: Size in bytes of the payload of the descriptor.

◆ replacePayload() [1/2]

void ts::Descriptor::replacePayload	(	const void *	data,
		size_t	size
	)

Replace the payload of the descriptor.

The tag is unchanged, the size is adjusted.

Parameters

[in]	data	Address of the new payload data.
[in]	size	Size in bytes of the new payload data.

◆ replacePayload() [2/2]

void ts::Descriptor::replacePayload ( const ByteBlock & payload )

inline

Replace the payload of the descriptor.

The tag is unchanged, the size is adjusted.

Parameters

[in] payload The new payload data.

◆ resizePayload()

void ts::Descriptor::resizePayload ( size_t size )

Resize (truncate or extend) the payload of the descriptor.

The tag is unchanged, the size is adjusted. If the payload is extended, new bytes are zeroes.

Parameters

[in] size New size in bytes of the payload.

◆ operator==() [1/2]

bool ts::Descriptor::operator== ( const Descriptor & other ) const

inline

Comparison operator.

Parameters

[in] other Another descriptor to compare.

Returns: True is the two descriptors are identical.

◆ deserialize() [1/2]

AbstractDescriptorPtr ts::Descriptor::deserialize	(	DuckContext &	duck,
		EDID	edid
	)		const

Deserialize the descriptor.

Parameters

[in,out]	duck	TSDuck execution context.
[in]	edid	Extended descriptor id.

Returns: A safe pointer to an instance of a concrete subclass of AbstractDescriptor representing this descriptor. Return the null pointer if the descriptor could not be deserialized.

◆ deserialize() [2/2]

AbstractDescriptorPtr ts::Descriptor::deserialize	(	DuckContext &	duck,
		DescriptorContext &	context
	)		const

Deserialize the descriptor.

Parameters

[in,out]	duck	TSDuck execution context.
[in,out]	context	Context of the descriptor. Used to understand its identity.

Returns: A safe pointer to an instance of a concrete subclass of AbstractDescriptor representing this descriptor. Return the null pointer if the descriptor could not be deserialized.

◆ toXML()

xml::Element * ts::Descriptor::toXML	(	DuckContext &	duck,
		xml::Element *	parent,
		DescriptorContext &	context,
		bool	force_generic = `false`
	)		const

This method converts a descriptor to XML.

If the descriptor has a specialized implementation, generate a specialized XML structure. Otherwise, generate a <generic_descriptor> node.

Parameters

[in,out]	duck	TSDuck execution context.
[in,out]	parent	The parent node for the XML descriptor.
[in,out]	context	Context of the descriptor. Used to understand its identity.
[in]	force_generic	Force a <generic_descriptor> node even if the descriptor can be specialized.

Returns: The new XML element or zero if the descriptor is not valid.

◆ fromXML() [1/2]

bool ts::Descriptor::fromXML	(	DuckContext &	duck,
		const xml::Element *	node,
		TID	tid = `TID_NULL`
	)

This method converts an XML node as a binary descriptor.

Parameters

[in,out]	duck	TSDuck execution context.
[in]	node	The root of the XML descriptor.
[in]	tid	Optional table id of the table containing the descriptor.

Returns: True if the XML element name is a valid descriptor name, false otherwise. If the name is valid but the content is incorrect, true is returned and this object is invalidated.

◆ fromXML() [2/2]

bool ts::Descriptor::fromXML	(	DuckContext &	duck,
		EDID &	edid,
		const xml::Element *	node,
		TID	tid = `TID_NULL`
	)

This method converts an XML node as a binary descriptor.

Parameters

[in,out]	duck	TSDuck execution context.
[out]	edid	Extended descriptor id of the XML descriptor.
[in]	node	The root of the XML descriptor.
[in]	tid	Optional table id of the table containing the descriptor.

Returns: True if the XML element name is a valid descriptor name, false otherwise. If the name is valid but the content is incorrect, true is returned and this object is invalidated.

◆ isValid()

virtual bool ts::DataBlock< LEN_OFFSET, LEN_SIZE, false >::isValid ( ) const

virtualinherited

Check if the data structure has valid content.

The base implementation only checks that the binary data are allocated. The various constructors or methods which replace the binary content already check the validity of the length field, when there is one. Subclasses may override this method with additional checks.

Returns: True if the descriptor has valid content.

◆ reload() [1/3]

void ts::DataBlock< LEN_OFFSET, LEN_SIZE, false >::reload	(	const void *	content,
		size_t	content_size
	)

inherited

Reload from full binary content.

Parameters

[in]	content	Address of the binary packet data.
[in]	content_size	Size in bytes of the packet.

◆ reload() [2/3]

void ts::DataBlock< LEN_OFFSET, LEN_SIZE, false >::reload ( const ByteBlock & content )

inherited

Reload from full binary content.

Parameters

[in] content Binary packet data. The content is copied into a new byte block.

◆ reload() [3/3]

void ts::DataBlock< LEN_OFFSET, LEN_SIZE, false >::reload ( const ByteBlockPtr & content_ptr )

inherited

Reload from full binary content.

Parameters

[in] content_ptr Safe pointer to the binary packet data. The content is referenced, and thus shared. Do not modify the referenced ByteBlock from outside the DataBlock.

◆ copy()

DataBlock & ts::DataBlock< LEN_OFFSET, LEN_SIZE, false >::copy ( const DataBlock< 8, 8 > & other )

inherited

Duplication.

Similar to assignment but the data are duplicated.

Parameters

[in] other Other data to duplicate into this object.

Returns: A reference to this object.

◆ operator==() [2/2]

bool ts::DataBlock< LEN_OFFSET, LEN_SIZE, false >::operator== ( const DataBlock< 8, 8 > & other ) const

inherited

Equality operator.

The source PID's are ignored, only the data contents are compared.

Parameters

[in] other Other packet to compare.

Returns: True if the two packets are identical. False otherwise.

◆ content()

virtual const uint8_t * ts::DataBlock< LEN_OFFSET, LEN_SIZE, false >::content ( ) const

virtualinherited

Access to the full binary content of the data.

Do not modify content.

Returns: Address of the full binary content of the data. May be invalidated after modification.

◆ size()

virtual size_t ts::DataBlock< LEN_OFFSET, LEN_SIZE, false >::size ( ) const

virtualinherited

Size of the logical binary content of the data.

For subclasses of DataBlock, this is the logical size of the data structure inside the DataBlock blob.

Returns: Size of the logical binary content of the data.

See also: rawDataSize()

◆ rawDataSize()

size_t ts::DataBlock< LEN_OFFSET, LEN_SIZE, false >::rawDataSize ( ) const

inlineinherited

Size of the complete binary raw data containing the logical structure.

Non-virtual method, always return the same result.

Returns: Size of the complete binary raw data.

See also: size()

◆ matchContent()

bool ts::DataBlock< LEN_OFFSET, LEN_SIZE, false >::matchContent	(	const ByteBlock &	pattern,
		const ByteBlock &	mask = `ByteBlock()`
	)		const

inherited

Check if the start of the data matches a given pattern.

Parameters

[in]	pattern	A byte block to compare with the start of the data.
[in]	mask	Optional mask to select meaningful bits in pattern.

Returns: Size of the binary content of the data.

◆ GetLengthField()

static size_t ts::DataBlock< LEN_OFFSET, LEN_SIZE, false >::GetLengthField	(	const void *	content,
		size_t	content_size
	)

staticinherited

Static method to extract the content of the length field.

Parameters

[in]	content	Address of the binary data. Can be the null pointer.
[in]	content_size	Size in bytes of the data.

Returns: The extracted length field or NPOS if the data structure does not contain a length field or if the length is "unbounded" (when allowed).

◆ ValidateLengthField()

static bool ts::DataBlock< LEN_OFFSET, LEN_SIZE, false >::ValidateLengthField	(	const void *	content,
		size_t	content_size,
		bool	allow_extra_data
	)

staticinherited

Static method to validate the content of the length field.

Parameters

[in]	content	Address of the binary data. Can be the null pointer.
[in]	content_size	Size in bytes of the data.
[in]	allow_extra_data	If true, additional data are allowed after the declared length.

Returns: True if the length field is valid, or the length field does not exist, or the length field is "unbounded" (when allowed).

◆ rwContent()

uint8_t * ts::DataBlock< LEN_OFFSET, LEN_SIZE, false >::rwContent ( )

inlineprotectedinherited

Read/write access to the full binary content of the data for subclasses.

Returns: Address of the full binary content of the data.

◆ rwResize()

void ts::DataBlock< LEN_OFFSET, LEN_SIZE, false >::rwResize ( size_t s )

protectedinherited

Resize the full binary content of the data for subclasses.

Parameters

[in] s New size in bytes of the full binary content of the data.

◆ rwAppend()

void ts::DataBlock< LEN_OFFSET, LEN_SIZE, false >::rwAppend	(	const void *	data,
		size_t	dsize
	)

protectedinherited

Append raw data to the full binary content of the data for subclasses.

Parameters

[in]	data	Address of the new area to append.
[in]	dsize	Size of the area to append.

Member Data Documentation

◆ LEN_BIT_SIZE

constexpr size_t ts::DataBlock< LEN_OFFSET, LEN_SIZE, false >::LEN_BIT_SIZE

staticconstexprinherited

Size in bits of the length field.

If zero, there is no length field.

◆ AFTER_LEN_BYTE_OFFSET

constexpr size_t ts::DataBlock< LEN_OFFSET, LEN_SIZE, false >::AFTER_LEN_BYTE_OFFSET

staticconstexprinherited

Offset in bytes of the next byte after the length field.

Zero if there is no length field.

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

tsDescriptor.h

Public Types

Public Member Functions

Static Public Member Functions

Static Public Attributes

Protected Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ Descriptor() [1/7]

◆ Descriptor() [2/7]

◆ Descriptor() [3/7]

◆ Descriptor() [4/7]

◆ Descriptor() [5/7]

◆ Descriptor() [6/7]

◆ Descriptor() [7/7]

Member Function Documentation

◆ tag()

◆ xdid()

◆ payload() [1/2]

◆ payload() [2/2]

◆ payloadSize()

◆ replacePayload() [1/2]

◆ replacePayload() [2/2]

◆ resizePayload()

◆ operator==() [1/2]

◆ deserialize() [1/2]

◆ deserialize() [2/2]

◆ toXML()

◆ fromXML() [1/2]

◆ fromXML() [2/2]

◆ isValid()

◆ reload() [1/3]

◆ reload() [2/3]

◆ reload() [3/3]

◆ copy()

◆ operator==() [2/2]

◆ content()

◆ size()

◆ rawDataSize()

◆ matchContent()

◆ GetLengthField()

◆ ValidateLengthField()

◆ rwContent()

◆ rwResize()

◆ rwAppend()

Member Data Documentation

◆ LEN_BIT_SIZE

◆ AFTER_LEN_BYTE_OFFSET