Representation of an ATSC Terrestrial Virtual Channel Table (TVCT) More...

#include <tsTVCT.h>

Inheritance diagram for ts::TVCT:

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Collaboration diagram for ts::TVCT:

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Public Types
using	ChannelList = EntryWithDescriptorsList< Channel >
	List of channels.

Public Member Functions
	TVCT (DuckContext &duck, const BinaryTable &table)
	Constructor from a binary table.

	TVCT (uint8_t version=0, bool is_current=true)
	Default constructor.

virtual	~TVCT () override
	Virtual destructor.

const UString &	attribute () const
	Get the generic user-defined "attribute" string of the table.

virtual void	clear () override final
	This method clears the content of the table or descriptor.

template<typename INT > requires std::integral<INT>
UString	dataName (const UChar *section, INT value, NamesFlags flags=NamesFlags::NAME, INT alternate=0, size_t bits=0)
	Get a name from a specified section in the DVB names file for that signalization structure.

virtual Standards	definingStandards () const override
	Get the list of standards which define this object.

bool	deserialize (DuckContext &duck, const BinaryTable &bin)
	This method deserializes a binary table.

ChannelList::const_iterator	findService (const UString &name, bool exact_match=false, bool same_ts=true) const
	Search a service by name.

bool	findService (Service &service, bool exact_match=false, bool same_ts=true) const
	Search a service by name or ATSC major.minor, using a ts::Service class.

ChannelList::const_iterator	findService (uint16_t id, bool same_ts=true) const
	Search a service by id.

ChannelList::const_iterator	findService (uint16_t major, uint16_t minor, bool same_ts=true) const
	Search a service by major.minor id.

virtual void	fromXML (DuckContext &duck, const xml::Element *element) override final
	This method converts an XML structure to a table or descriptor in this object.

void	invalidate ()
	Invalidate this object.

virtual bool	isPrivate () const
	Check if the table is a private one (ie.

bool	isValid () const
	Check if this object is valid.

bool	serialize (DuckContext &duck, BinaryTable &bin) const
	This method serializes a table.

void	setAttribute (const UString &attr)
	Set a generic user-defined string as "attribute" of the table.

TID	tableId () const
	Get the table_id.

virtual uint16_t	tableIdExtension () const override
	Get the table id extension.

virtual const DescriptorList *	topLevelDescriptorList () const override
	Get the address of the "top-level descriptor list" of the table (constant).

virtual DescriptorList *	topLevelDescriptorList () override
	Get the address of the "top-level descriptor list" of the table.

virtual xml::Element *	toXML (DuckContext &duck, xml::Element *parent) const override final
	This method converts this object to XML.

void	updateServices (DuckContext &duck, ServiceList &services) const
	Collect all informations about all services in the VCT.

UString	xmlName () const
	Get the XMl node name representing this table or descriptor.

Static Public Member Functions
template<typename INT > requires std::integral<INT>
static UString	DataName (const UChar xml_name, const UChar section, INT value, NamesFlags flags=NamesFlags::NAME, INT alternate=0, size_t bits=0)
	Get a name from a specified section in the DVB names file.

static void	DisplaySection (ts::TablesDisplay &display, const ts::Section &section, ts::PSIBuffer &payload, const ts::UString &margin)
	A static method to display a section.

static xml::Element *	GetOrCreateMetadata (xml::Element *element)
	Get the <metadata> structure inside a XML element representing a table.

Public Attributes
ChannelList	channels
	List of channels which are described in this VCT.

DescriptorList	descs
	Program-level descriptor list.

bool	is_current = true
	True if table is current, false if table is next.

uint8_t	protocol_version = 0
	ATSC protocol version.

uint16_t	transport_stream_id = 0
	Transport stream id.

uint8_t	version = 0
	Table version number.

Static Public Attributes
static const UChar *const	XML_GENERIC_DESCRIPTOR
	XML tag name for generic descriptors.

static const UChar *const	XML_GENERIC_LONG_TABLE
	XML tag name for generic tables with long sections.

static const UChar *const	XML_GENERIC_SHORT_TABLE
	XML tag name for generic short sections.

Protected Member Functions
void	addOneSection (BinaryTable &table, PSIBuffer &payload) const
	Helper method for serializePayload(): add a section in a binary table.

virtual void	addOneSectionImpl (BinaryTable &, PSIBuffer &) const override
	Actual implementation of adding one section in a binary table.

virtual bool	analyzeXML (DuckContext &, const xml::Element *) override
	Helper method to convert this object from XML.

virtual void	buildXML (DuckContext &, xml::Element *) const override
	Helper method to convert this object to XML.

virtual void	clearContent () override
	Helper method to clear the content of the table or descriptor.

virtual void	deserializePayload (PSIBuffer &, const Section &) override
	This abstract method deserializes the payload of one section.

virtual void	deserializePayloadWrapper (PSIBuffer &, const Section &) override
	Wrapper for deserializePayload().

virtual bool	isValidTableId (TID tid) const
	This method checks if a table id is valid for this object.

virtual size_t	maxPayloadSize () const override
	Get the maximum size in bytes of the payload of sections of this table.

virtual void	serializePayload (BinaryTable &, PSIBuffer &) const override
	This abstract method serializes the payload of all sections in the table.

virtual bool	useTrailingCRC32 () const override
	Check if the sections of this table have a trailing CRC32.

Protected Attributes
TID	_table_id = TID_NULL
	The table id can be modified by subclasses only.

Detailed Description

Representation of an ATSC Terrestrial Virtual Channel Table (TVCT)

See also: ATSC A/65, section 6.3.1.

Constructor & Destructor Documentation

◆ TVCT() [1/2]

ts::TVCT::TVCT	(	uint8_t	version = `0`,
		bool	is_current = `true`
	)

Default constructor.

Parameters

[in]	version	Table version number.
[in]	is_current	True if table is current, false if table is next.

◆ TVCT() [2/2]

ts::TVCT::TVCT	(	DuckContext &	duck,
		const BinaryTable &	table
	)

Constructor from a binary table.

Parameters

[in,out]	duck	TSDuck execution context.
[in]	table	Binary table to deserialize.

Member Function Documentation

◆ findService() [1/4]

ChannelList::const_iterator ts::VCT::findService	(	uint16_t	id,
		bool	same_ts = `true`
	)		const

inherited

Search a service by id.

Parameters

[in]	id	Service id to search.
[in]	same_ts	If true, only look for services in the same TS as the VCT.

Returns: An iterator to the service if found, channels.end() if not found.

◆ findService() [2/4]

ChannelList::const_iterator ts::VCT::findService	(	uint16_t	major,
		uint16_t	minor,
		bool	same_ts = `true`
	)		const

inherited

Search a service by major.minor id.

Parameters

[in]	major	Major id to search.
[in]	minor	Minor id to search.
[in]	same_ts	If true, only look for services in the same TS as the VCT.

Returns: An iterator to the service if found, channels.end() if not found.

◆ findService() [3/4]

ChannelList::const_iterator ts::VCT::findService	(	const UString &	name,
		bool	exact_match = `false`,
		bool	same_ts = `true`
	)		const

inherited

Search a service by name.

Parameters

[in]	name	Service name to search.
[in]	exact_match	If true, the service name must be exactly identical to name. If it is false, the search is case-insensitive and blanks are ignored.
[in]	same_ts	If true, only look for services in the same TS as the VCT.

Returns: An iterator to the service if found, channels.end() if not found.

◆ findService() [4/4]

bool ts::VCT::findService	(	Service &	service,
		bool	exact_match = `false`,
		bool	same_ts = `true`
	)		const

inherited

Search a service by name or ATSC major.minor, using a ts::Service class.

Parameters

[in,out]	service	Service description. Use service name or major.minor to search. Set the service id if found.
[in]	exact_match	If true, the service name must be exactly identical to the name in service. If it is false, the search is case-insensitive and blanks are ignored.
[in]	same_ts	If true, only look for services in the same TS as the VCT.

Returns: True if the service is found, false if not found.

◆ updateServices()

void ts::VCT::updateServices	(	DuckContext &	duck,
		ServiceList &	services
	)		const

inherited

Collect all informations about all services in the VCT.

Parameters

[in,out]	duck	TSDuck execution context.
[in,out]	services	A list of service descriptions. Existing services are updated with the informations from the SDT. New entries are created for other services.

◆ tableIdExtension()

virtual uint16_t ts::VCT::tableIdExtension ( ) const

overridevirtualinherited

Get the table id extension.

The table id extension is a 16-bit field which usually contains one of the table fields (service id, transport stream id, etc.) For each subclass, the table id extension is usually directly available in the corresponding public field. This virtual method is a generic way to access the table id extension.

Returns: The table id extension.

Implements ts::AbstractLongTable.

◆ topLevelDescriptorList() [1/2]

virtual DescriptorList * ts::VCT::topLevelDescriptorList ( )

overridevirtualinherited

Get the address of the "top-level descriptor list" of the table.

Some tables have descriptor lists, and sometimes two levels of descriptor lists. This is the case of the PMT, NIT, BAT, etc. The "top-level descriptor list" is present once in the table. It describes the service (PMT), the network (NIT) or the operator (BAT). At the second level, there is one descriptor list per component (PMT), or per transport stream (NIT, BAT). Sometimes, when exploring a second-level descriptor list, it is useful to also explore the top-level descriptor list. This virtual method returns a pointer to the top-level descriptor list. Thus, when exploring a second-level descriptor list, using the table pointer in that list, we can get a reference to the higher-level list.

The default implementation returns the null pointer.

Returns: The address of the "top-level descriptor list" of the table, if there is one. Return the null pointer if there is no such descriptor list.

Reimplemented from ts::AbstractTable.

◆ topLevelDescriptorList() [2/2]

virtual const DescriptorList * ts::VCT::topLevelDescriptorList ( ) const

overridevirtualinherited

Get the address of the "top-level descriptor list" of the table (constant).

Returns: The address of the "top-level descriptor list" of the table, if there is one. Return the null pointer if there is no such descriptor list.

See also: DescriptorList* topLevelDescriptorList()

Reimplemented from ts::AbstractTable.

◆ DisplaySection()

static void ts::VCT::DisplaySection	(	ts::TablesDisplay &	display,
		const ts::Section &	section,
		ts::PSIBuffer &	payload,
		const ts::UString &	margin
	)

staticinherited

A static method to display a section.

Parameters

[in,out]	display	Display engine.
[in]	section	The section to display.
[in,out]	payload	A PSIBuffer over the payload.
[in]	margin	Left margin content.

◆ clearContent()

virtual void ts::VCT::clearContent ( )

overrideprotectedvirtualinherited

Helper method to clear the content of the table or descriptor.

It is called by clear(). In clearContent(), the subclass shall simply revert the value of all fields to their original values in the default constructor.

Implements ts::AbstractSignalization.

◆ maxPayloadSize()

virtual size_t ts::VCT::maxPayloadSize ( ) const

overrideprotectedvirtualinherited

Get the maximum size in bytes of the payload of sections of this table.

Returns: The maximum size in bytes of the payload of sections of this table.

Reimplemented from ts::AbstractLongTable.

◆ serializePayload()

virtual void ts::VCT::serializePayload	(	BinaryTable &	table,
		PSIBuffer &	buf
	)		const

overrideprotectedvirtualinherited

This abstract method serializes the payload of all sections in the table.

When serialize() is called, the output binary table is cleared and serializePayload() is called. A subclass shall implement serializePayload() which adds all required sections in the binary table.

Note that it is not necessary to explicitly add the last (or only) section. Upon return from serializePayload(), serialize() checks the state of the payload buffer. If the output binary table is still empty or if the payload buffer is not empty (or not empty after the last saved write position), then addOneSection() is automatically called.

Parameters

[in,out]	table	The binary table into which this object shall be serialized. The table is initially empty when serialize() calls serializePayload().
[in,out]	buf	A PSIBuffer with the appropriate size for the section payload. The payload buffer is initially empty when serialize() calls serializePayload().

Implements ts::AbstractTable.

◆ deserializePayload()

virtual void ts::VCT::deserializePayload	(	PSIBuffer &	buf,
		const Section &	section
	)

overrideprotectedvirtualinherited

This abstract method deserializes the payload of one section.

When deserialize() is called, this object is cleared and validated. Then, deserializePayload() is invoked for each section in the binary table. A subclass shall implement deserializePayload() which adds the content of the binary section to the C++ object. Do not reset the object in deserializePayload() since it is repeatedly called for each section of a single binary table.

Parameters

[in,out]	buf	Deserialization buffer. The subclass shall read the descriptor payload from buf. The end of read is the end of the binary payload. If any kind of error is reported in the buffer or if the payload is not completely read, the deserialization is considered as invalid.
[in]	section	A reference to the section. Can be used to access values in the section header (typically for long sections).

Implements ts::AbstractTable.

◆ buildXML()

virtual void ts::VCT::buildXML	(	DuckContext &	duck,
		xml::Element *	root
	)		const

overrideprotectedvirtualinherited

Helper method to convert this object to XML.

It is called by toXML() only when the object is valid. The root element is already built with the appropriate XML node name. In buildXML(), the subclass shall simply populate the XML node.

Parameters

[in,out]	root	The root node for the new XML tree.
[in,out]	duck	TSDuck execution context.

Implements ts::AbstractSignalization.

◆ analyzeXML()

virtual bool ts::VCT::analyzeXML	(	DuckContext &	duck,
		const xml::Element *	element
	)

overrideprotectedvirtualinherited

Helper method to convert this object from XML.

It is called by fromXML() after checking the validity of the XML node name. In analyzeXML(), the subclass shall populate the C++ object from the content of the XML node. If analyzeXML() returns false, this table or descriptor object is then invalidated and cleared.

Parameters

[in,out]	duck	TSDuck execution context.
[in]	element	XML element to convert.

Returns: True if the analysis is correct, false otherwise.

Implements ts::AbstractSignalization.

◆ clear()

virtual void ts::AbstractLongTable::clear ( )

finaloverridevirtualinherited

This method clears the content of the table or descriptor.

Upon return, the object is valid and in the same empty state as after a default constructor.

Reimplemented from ts::AbstractTable.

◆ useTrailingCRC32()

virtual bool ts::AbstractLongTable::useTrailingCRC32 ( ) const

overrideprotectedvirtualinherited

Check if the sections of this table have a trailing CRC32.

This is usually false for short sections but some short sections such as DVB-TOT use a CRC32.

Returns: True if the sections of this table have a trailing CRC32.

Reimplemented from ts::AbstractTable.

◆ deserializePayloadWrapper()

virtual void ts::AbstractLongTable::deserializePayloadWrapper	(	PSIBuffer &	buf,
		const Section &	section
	)

overrideprotectedvirtualinherited

Wrapper for deserializePayload().

This is a method to overload in intermediate classes to avoid using "call superclass" to all tables.

Parameters

[in,out]	buf	Deserialization buffer.
[in]	section	A reference to the section.

Reimplemented from ts::AbstractTable.

◆ addOneSectionImpl()

virtual void ts::AbstractLongTable::addOneSectionImpl	(	BinaryTable &	table,
		PSIBuffer &	payload
	)		const

overrideprotectedvirtualinherited

Actual implementation of adding one section in a binary table.

Do not call directly, it is only called by addOneSection() and is overridden in AbstractLongTable.

Parameters

[in,out]	table	The binary table into which the new section shall be added.
[in,out]	payload	A PSIBuffer containing the section payload between the read and the write pointer.

Reimplemented from ts::AbstractTable.

◆ tableId()

TID ts::AbstractTable::tableId ( ) const

inlineinherited

Get the table_id.

Returns: The table_id.

◆ isPrivate()

virtual bool ts::AbstractTable::isPrivate ( ) const

virtualinherited

Check if the table is a private one (ie.

not MPEG-defined). The default implementation returns true. MPEG-defined tables should override this method to return false.

Returns: True if the table is a private one (ie. not MPEG-defined).

Reimplemented in ts::CAT, ts::DSMCCStreamDescriptorsTable, ts::PAT, ts::PMT, ts::TSDT, ts::CableEmergencyAlertTable, and ts::SpliceInformationTable.

◆ serialize()

bool ts::AbstractTable::serialize	(	DuckContext &	duck,
		BinaryTable &	bin
	)		const

inherited

This method serializes a table.

Parameters

[in,out]	duck	TSDuck execution context.
[out]	bin	A binary table object. Its content is replaced with a binary representation of this object.

Returns: True in case of success, false if the table is invalid.

◆ deserialize()

bool ts::AbstractTable::deserialize	(	DuckContext &	duck,
		const BinaryTable &	bin
	)

inherited

This method deserializes a binary table.

In case of success, this object is replaced with the interpreted content of bin. In case of error, this object is invalidated.

Parameters

[in,out]	duck	TSDuck execution context.
[in]	bin	A binary table to interpret according to the table subclass.

Returns: True in case of success, false if the table is invalid.

◆ setAttribute()

void ts::AbstractTable::setAttribute ( const UString & attr )

inlineinherited

Set a generic user-defined string as "attribute" of the table.

The semantics of this attribute string is not defined. It is used by the application. The attribute string can be found in the <metadata> structure of the XML representation of the table.

Parameters

[in] attr Generic string to set as attribute.

◆ attribute()

const UString & ts::AbstractTable::attribute ( ) const

inlineinherited

Get the generic user-defined "attribute" string of the table.

Returns: A constant reference to the attribute string in the object.

See also: setAttribute()

◆ toXML()

virtual xml::Element * ts::AbstractTable::toXML	(	DuckContext &	duck,
		xml::Element *	parent
	)		const

finaloverridevirtualinherited

This method converts this object to XML.

When this object is valid, this method creates a root node with the default XML name and then invokes buildXML() in the subclass to populate the XML node.

Important: Implementers of signalization classes shall not override this class. Implement the protected method buildXML() instead.

Parameters

[in,out]	duck	TSDuck execution context.
[in,out]	parent	The parent node for the new XML tree.

Returns: The new XML element.

Reimplemented from ts::AbstractSignalization.

◆ fromXML()

virtual void ts::AbstractTable::fromXML	(	DuckContext &	duck,
		const xml::Element *	element
	)

finaloverridevirtualinherited

This method converts an XML structure to a table or descriptor in this object.

In case of success, this object is replaced with the interpreted content of the XML structure. In case of error, this object is invalidated.

This method checks the name of the XML node and then invokes analyzeXML() in the subclass. Depending on the returned values of analyzeXML(), this object is either validated or invalidated.

Important: Implementers of signalization classes shall not override this class. Implement the protected method analyzeXML() instead.

Parameters

[in,out]	duck	TSDuck execution context.
[in]	element	XML element to convert.

Reimplemented from ts::AbstractSignalization.

◆ GetOrCreateMetadata()

static xml::Element * ts::AbstractTable::GetOrCreateMetadata ( xml::Element * element )

staticinherited

Get the <metadata> structure inside a XML element representing a table.

If the <metadata> structure does not exist, it is created.

Parameters

[in,out] element The XML element representing a table.

Returns: The <metadata> structure inside element. Never null, unless element is null.

◆ isValidTableId()

virtual bool ts::AbstractTable::isValidTableId ( TID tid ) const

protectedvirtualinherited

This method checks if a table id is valid for this object.

Parameters

[in] tid A table id to check.

Returns: True if tid is a valid table id for this object, false otherwise. The default implementation checks that tid is identical to the table id of this object.

Reimplemented in ts::EIT, ts::NIT, ts::SDT, and ts::NBIT.

◆ addOneSection()

void ts::AbstractTable::addOneSection	(	BinaryTable &	table,
		PSIBuffer &	payload
	)		const

protectedinherited

Helper method for serializePayload(): add a section in a binary table.

For long tables, the section number is always one more than the current last section in the table.

If the payload buffer has a pushed read/write state, this state is restored and immediately pushed again. The typical use case is the following:

A table may create more than one section.
The payload of all sections starts with the same fixed data.
In the subclass, the method serializePayload() builds the initial fixed data once.
The method serializePayload() immediately pushes the read/write state of the buffer.
The method serializePayload() builds payloads and call addOneSection().
Upon return from addOneSection(), the buffer is back right after the initial fixed data.

Parameters

[in,out]	table	The binary table into which the new section shall be added.
[in,out]	payload	A PSIBuffer containing the section payload between the read and the write pointer.

◆ isValid()

bool ts::AbstractSignalization::isValid ( ) const

inlineinherited

Check if this object is valid.

Returns: True if this object is valid.

◆ invalidate()

void ts::AbstractSignalization::invalidate ( )

inlineinherited

Invalidate this object.

This object must be rebuilt.

◆ xmlName()

UString ts::AbstractSignalization::xmlName ( ) const

inherited

Get the XMl node name representing this table or descriptor.

Returns: The XML node name.

◆ definingStandards()

virtual Standards ts::AbstractSignalization::definingStandards ( ) const

overridevirtualinherited

Get the list of standards which define this object.

Returns: A bit mask of standards.

Implements ts::AbstractDefinedByStandards.

Reimplemented in ts::AbstractDescriptor.

◆ DataName()

template<typename INT >
requires std::integral<INT>

static UString ts::AbstractSignalization::DataName	(	const UChar *	xml_name,
		const UChar *	section,
		INT	value,
		NamesFlags	flags = `NamesFlags::NAME`,
		INT	alternate = `0`,
		size_t	bits = `0`
	)

inlinestaticinherited

Get a name from a specified section in the DVB names file.

Template Parameters

INT	An integer type.

Parameters

[in]	xml_name	Table or descriptor name, as used in XML structures.
[in]	section	Name of section to search. Not case-sensitive. The actual section in the names file is prefixed by the XML name, followed by a dot.
[in]	value	Value to get the name for.
[in]	flags	Presentation flags.
[in]	alternate	Display this integer value if flags ALTERNATE is set.
[in]	bits	Optional size in bits of the displayed data. Used in replacement of the "Bits=XX" directive in the .names file.

Returns: The corresponding name.

◆ dataName()

template<typename INT >
requires std::integral<INT>

UString ts::AbstractSignalization::dataName	(	const UChar *	section,
		INT	value,
		NamesFlags	flags = `NamesFlags::NAME`,
		INT	alternate = `0`,
		size_t	bits = `0`
	)

inlineinherited

Get a name from a specified section in the DVB names file for that signalization structure.

Template Parameters

INT	An integer type.

Parameters

[in]	section	Name of section to search. Not case-sensitive. The actual section in the names file is prefixed by the XML name of the structure, followed by a dot.
[in]	value	Value to get the name for.
[in]	flags	Presentation flags.
[in]	alternate	Display this integer value if flags ALTERNATE is set.
[in]	bits	Optional size in bits of the displayed data. Used in replacement of the "Bits=XX" directive in the .names file.

Returns: The corresponding name.

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

tsTVCT.h

Public Types

Public Member Functions

Static Public Member Functions

Public Attributes

Static Public Attributes

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ TVCT() [1/2]

◆ TVCT() [2/2]

Member Function Documentation

◆ findService() [1/4]

◆ findService() [2/4]

◆ findService() [3/4]

◆ findService() [4/4]

◆ updateServices()

◆ tableIdExtension()

◆ topLevelDescriptorList() [1/2]

◆ topLevelDescriptorList() [2/2]

◆ DisplaySection()

◆ clearContent()

◆ maxPayloadSize()

◆ serializePayload()

◆ deserializePayload()

◆ buildXML()

◆ analyzeXML()

◆ clear()

◆ useTrailingCRC32()

◆ deserializePayloadWrapper()

◆ addOneSectionImpl()

◆ tableId()

◆ isPrivate()

◆ serialize()

◆ deserialize()

◆ setAttribute()

◆ attribute()

◆ toXML()

◆ fromXML()

◆ GetOrCreateMetadata()

◆ isValidTableId()

◆ addOneSection()

◆ isValid()

◆ invalidate()

◆ xmlName()

◆ definingStandards()

◆ DataName()

◆ dataName()