Cyclic packetization of MPEG sections into Transport Stream packets. More...

#include <tsCyclingPacketizer.h>

Inheritance diagram for ts::CyclingPacketizer:

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Collaboration diagram for ts::CyclingPacketizer:

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Public Types
enum class	StuffingPolicy { NEVER , AT_END , ALWAYS }
	Specify where stuffing applies. More...

Public Member Functions
	CyclingPacketizer (const DuckContext &duck, PID pid=PID_NULL, StuffingPolicy policy=StuffingPolicy::AT_END, const BitRate &bitrate=0)
	Default constructor.

virtual	~CyclingPacketizer () override
	Destructor.

void	addSection (const SectionPtr &section, cn::milliseconds repetition_rate=cn::milliseconds::zero())
	Add one section into the packetizer.

void	addSections (const SectionPtrVector &sections, cn::milliseconds repetition_rate=cn::milliseconds::zero())
	Add some sections into the packetizer.

void	addTable (const BinaryTable &table, cn::milliseconds repetition_rate=cn::milliseconds::zero())
	Add all sections of a binary table into the packetizer.

void	addTable (DuckContext &duck, const AbstractTable &table, cn::milliseconds repetition_rate=cn::milliseconds::zero())
	Add all sections of a typed table into the packetizer.

void	allowHeaderSplit (bool allow)
	Allow or disallow splitting section headers across TS packets.

bool	atCycleBoundary () const
	Check if the last generated packet was the last packet in the cycle.

bool	atSectionBoundary () const
	Check if the packet stream is exactly at a section boundary.

BitRate	bitRate () const
	Get the bitrate of the generated PID.

virtual std::ostream &	display (std::ostream &strm) const override
	Display the internal state of the packetizer, mainly for debug.

const DuckContext &	duck () const
	Get a reference to the TSDuck execution context.

virtual bool	getNextPacket (TSPacket &packet) override
	Build the next MPEG packet for the list of items (sections or PES) to pacjetize.

PID	getPID () const
	Get the default PID for subsequent MPEG packets.

bool	headerSplitAllowed () const
	Check if splitting section headers across TS packets is allowed.

uint8_t	nextContinuityCounter () const
	Get the continuity counter value for next MPEG packet.

PacketCounter	packetCount () const
	Get the number of generated TS packets so far.

void	removeAll ()
	Remove all sections in the packetizer.

void	removeSections (TID tid)
	Remove all sections with the specified table id.

void	removeSections (TID tid, uint16_t tid_ext)
	Remove all sections with the specified table id and table id extension.

void	removeSections (TID tid, uint16_t tid_ext, uint8_t sec_number)
	Remove all sections with the specified table id, table id extension and section number.

Report &	report () const
	Get a reference to the debugging report.

virtual void	reset () override
	Reset the packetizer.

SectionCounter	sectionCount () const
	Get the number of completely packetized sections so far.

SectionProviderInterface *	sectionProvider () const
	Get the object which provides MPEG sections when the packetizer needs a new section.

void	setBitRate (const BitRate &bitrate)
	Set the bitrate of the generated PID.

void	setNextContinuityCounter (uint8_t cc)
	Set the continuity counter value for next MPEG packet.

void	setPID (PID pid)
	Set the default PID for subsequent MPEG packets.

void	setStuffingPolicy (StuffingPolicy sp)
	Set the TS packet stuffing policy at end of packet.

SectionCounter	storedSectionCount () const
	Get the number of stored sections to packetize.

StuffingPolicy	stuffingPolicy () const
	Get the TS packet stuffing policy at end of packet.

Protected Member Functions
void	configurePacket (TSPacket &pkt, bool nullify)
	Configure a TS packet with continuity and PID.

Detailed Description

Cyclic packetization of MPEG sections into Transport Stream packets.

A CyclingPacketizer contains various sections to be packetized on one PID.

All packets are generated on demand. The generated packets have the right PID and continuity counters and can be directly injected in a transport stream.

The "cycle" of the packetizer is defined as the smallest set of TS packets containing all sections, with respect to the broadcasting constraints (stuffing, specific repetition rates, etc).

It is possible to set different repetition rates for sections. In that case, the target "bitrate" of the PID must be specified. The sections are inserted on a best effort basis to respect the minimum repetition rates.

When the packetizer bitrate is specified as zero (the default), the target bitrate of the PID is unspecified. The repetition rates of sections are ignored.

Note that when sections have different repetition rates, some sections may be repeated into one cycle of the Packetizer.

Section stuffing may occur at the end of a section. If the section ends in the middle of an MPEG packet, the beginning of the next section can start immediately or can be delayed to the beginning of the next packet. In the later case, the rest of the current packet is filled with stuffing bytes (0xFF).

A bitrate is specified in bits/second. Zero means undefined. A repetition rate is specified in milliseconds. Zero means undefined.

Member Enumeration Documentation

◆ StuffingPolicy

enum class ts::CyclingPacketizer::StuffingPolicy

strong

Specify where stuffing applies.

Enumerator
NEVER	No stuffing, always pack sections.
AT_END	Stuffing at end of cycle, pack sections inside cycle.
ALWAYS	Always stuffing, never pack sections.

Constructor & Destructor Documentation

◆ CyclingPacketizer()

ts::CyclingPacketizer::CyclingPacketizer	(	const DuckContext &	duck,
		PID	pid = `PID_NULL`,
		StuffingPolicy	policy = `StuffingPolicy::AT_END`,
		const BitRate &	bitrate = `0`
	)

Default constructor.

Parameters

[in]	duck	TSDuck execution context. The reference is kept inside the packetizer.
[in]	pid	PID for generated TS packets.
[in]	policy	TS packet stuffing policy at end of packet.
[in]	bitrate	Output bitrate, zero if undefined. Useful only when using specific repetition rates for sections

Member Function Documentation

◆ setStuffingPolicy()

void ts::CyclingPacketizer::setStuffingPolicy ( StuffingPolicy sp )

inline

Set the TS packet stuffing policy at end of packet.

Parameters

[in] sp TS packet stuffing policy at end of packet.

◆ stuffingPolicy()

StuffingPolicy ts::CyclingPacketizer::stuffingPolicy ( ) const

inline

Get the TS packet stuffing policy at end of packet.

Returns: TS packet stuffing policy at end of packet.

◆ setBitRate()

void ts::CyclingPacketizer::setBitRate ( const BitRate & bitrate )

Set the bitrate of the generated PID.

Useful only when using specific repetition rates for sections

Parameters

[in] bitrate Output bitrate, zero if undefined.

◆ bitRate()

BitRate ts::CyclingPacketizer::bitRate ( ) const

inline

Get the bitrate of the generated PID.

Returns: Output bitrate, zero if undefined.

◆ addSection()

void ts::CyclingPacketizer::addSection	(	const SectionPtr &	section,
		cn::milliseconds	repetition_rate = `cn::milliseconds::zero()`
	)

Add one section into the packetizer.

The contents of the sections are shared.

Parameters

[in]	section	A smart pointer to the section to packetize.
[in]	repetition_rate	Repetition rate of the section in milliseconds. If zero, simply packetize sections one after the other.

◆ addSections()

void ts::CyclingPacketizer::addSections	(	const SectionPtrVector &	sections,
		cn::milliseconds	repetition_rate = `cn::milliseconds::zero()`
	)

Add some sections into the packetizer.

The contents of the sections are shared.

Parameters

[in]	sections	A vector of smart pointer to the sections to packetize.
[in]	repetition_rate	Repetition rate of the sections in milliseconds. If zero, simply packetize sections one after the other.

◆ addTable() [1/2]

void ts::CyclingPacketizer::addTable	(	const BinaryTable &	table,
		cn::milliseconds	repetition_rate = `cn::milliseconds::zero()`
	)

Add all sections of a binary table into the packetizer.

The contents of the sections are shared. If the table is not complete (there are missing sections), the sections which are present are individually added.

Parameters

[in]	table	A binary table to packetize.
[in]	repetition_rate	Repetition rate of the sections in milliseconds. If zero, simply packetize sections one after the other.

◆ addTable() [2/2]

void ts::CyclingPacketizer::addTable	(	DuckContext &	duck,
		const AbstractTable &	table,
		cn::milliseconds	repetition_rate = `cn::milliseconds::zero()`
	)

Add all sections of a typed table into the packetizer.

Parameters

[in,out]	duck	TSDuck execution context.
[in]	table	A table to packetize.
[in]	repetition_rate	Repetition rate of the sections in milliseconds. If zero, simply packetize sections one after the other.

◆ removeSections() [1/3]

void ts::CyclingPacketizer::removeSections ( TID tid )

Remove all sections with the specified table id.

If one such section is currently being packetized, the rest of the section will be packetized.

Parameters

[in] tid The table id of the sections to remove.

◆ removeSections() [2/3]

void ts::CyclingPacketizer::removeSections	(	TID	tid,
		uint16_t	tid_ext
	)

Remove all sections with the specified table id and table id extension.

If one such section is currently being packetized, the rest of the section will be packetized.

Parameters

[in]	tid	The table id of the sections to remove.
[in]	tid_ext	The table id extension of the sections to remove.

◆ removeSections() [3/3]

void ts::CyclingPacketizer::removeSections	(	TID	tid,
		uint16_t	tid_ext,
		uint8_t	sec_number
	)

Remove all sections with the specified table id, table id extension and section number.

If one such section is currently being packetized, the rest of the section will be packetized.

Parameters

[in]	tid	The table id of the sections to remove.
[in]	tid_ext	The table id extension of the sections to remove.
[in]	sec_number	The section number of the sections to remove.

◆ removeAll()

void ts::CyclingPacketizer::removeAll ( )

Remove all sections in the packetizer.

If a section is currently being packetized, the rest of the section will be packetized.

◆ storedSectionCount()

SectionCounter ts::CyclingPacketizer::storedSectionCount ( ) const

inline

Get the number of stored sections to packetize.

Returns: The number of stored sections to packetize.

◆ atCycleBoundary()

bool ts::CyclingPacketizer::atCycleBoundary ( ) const

Check if the last generated packet was the last packet in the cycle.

Note that if the stuffing policy is NEVER, this is not reliable since it is unlikely that a packet actually terminates a cycle.

Returns: True when the last generated packet was the last packet in the cycle.

◆ reset()

virtual void ts::CyclingPacketizer::reset ( )

overridevirtual

Reset the packetizer.

All unfinished items (sections or PES packets) are dropped.

Reimplemented from ts::Packetizer.

◆ display()

virtual std::ostream & ts::CyclingPacketizer::display ( std::ostream & strm ) const

overridevirtual

Display the internal state of the packetizer, mainly for debug.

Parameters

[in,out] strm Output text stream.

Returns: A reference to strm.

Reimplemented from ts::Packetizer.

◆ sectionProvider()

SectionProviderInterface * ts::Packetizer::sectionProvider ( ) const

inlineinherited

Get the object which provides MPEG sections when the packetizer needs a new section.

Returns: The object which will be called each time a section is required.

◆ atSectionBoundary()

bool ts::Packetizer::atSectionBoundary ( ) const

inlineinherited

Check if the packet stream is exactly at a section boundary.

Returns: True if the last returned packet contained the end of a section and no unfinished section.

◆ sectionCount()

SectionCounter ts::Packetizer::sectionCount ( ) const

inlineinherited

Get the number of completely packetized sections so far.

Returns: The number of completely packetized sections so far.

◆ allowHeaderSplit()

void ts::Packetizer::allowHeaderSplit ( bool allow )

inlineinherited

Allow or disallow splitting section headers across TS packets.

By default, a Packetizer never splits a section header between two TS packets. This is not required by the MPEG standard but some STB are known to have problems with that.

Parameters

[in] allow If true, splitting section headers across TS packets is allowed.

◆ headerSplitAllowed()

bool ts::Packetizer::headerSplitAllowed ( ) const

inlineinherited

Check if splitting section headers across TS packets is allowed.

Returns: True if splitting section headers across TS packets is allowed.

◆ getNextPacket()

virtual bool ts::Packetizer::getNextPacket ( TSPacket & packet )

overridevirtualinherited

Build the next MPEG packet for the list of items (sections or PES) to pacjetize.

If there is nothing to packetize, generate a null packet on PID_NULL.

Parameters

[out] packet The next TS packet.

Returns: True if a real packet is returned, false if a null packet was returned.

Implements ts::AbstractPacketizer.

◆ setPID()

void ts::AbstractPacketizer::setPID ( PID pid )

inlineinherited

Set the default PID for subsequent MPEG packets.

Parameters

[in] pid PID for generated TS packets.

◆ getPID()

PID ts::AbstractPacketizer::getPID ( ) const

inlineinherited

Get the default PID for subsequent MPEG packets.

Returns: PID for generated TS packets.

◆ setNextContinuityCounter()

void ts::AbstractPacketizer::setNextContinuityCounter ( uint8_t cc )

inlineinherited

Set the continuity counter value for next MPEG packet.

This counter is automatically incremented at each packet. It is usually never a good idea to change this, except maybe before generating the first packet if the continuity must be preserved with the previous content of the PID.

Parameters

[in] cc Next continuity counter.

◆ nextContinuityCounter()

uint8_t ts::AbstractPacketizer::nextContinuityCounter ( ) const

inlineinherited

Get the continuity counter value for next MPEG packet.

Returns: Next continuity counter.

◆ packetCount()

PacketCounter ts::AbstractPacketizer::packetCount ( ) const

inlineinherited

Get the number of generated TS packets so far.

Returns: The number of generated TS packets so far.

◆ report()

Report & ts::AbstractPacketizer::report ( ) const

inlineinherited

Get a reference to the debugging report.

Returns: A reference to the debugging report.

◆ duck()

const DuckContext & ts::AbstractPacketizer::duck ( ) const

inlineinherited

Get a reference to the TSDuck execution context.

Returns: A reference to the TSDuck execution context.

◆ configurePacket()

void ts::AbstractPacketizer::configurePacket	(	TSPacket &	pkt,
		bool	nullify
	)

protectedinherited

Configure a TS packet with continuity and PID.

Also increment the number of generated packet. So this method must be called exactly once per packet.

Parameters

[in,out]	pkt	TS packet to configure
[in]	nullify	Return a null packet instead (no data to return for now).

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

tsCyclingPacketizer.h

Public Types

Public Member Functions

Protected Member Functions

Detailed Description

Member Enumeration Documentation

◆ StuffingPolicy

Constructor & Destructor Documentation

◆ CyclingPacketizer()

Member Function Documentation

◆ setStuffingPolicy()

◆ stuffingPolicy()

◆ setBitRate()

◆ bitRate()

◆ addSection()

◆ addSections()

◆ addTable() [1/2]

◆ addTable() [2/2]

◆ removeSections() [1/3]

◆ removeSections() [2/3]

◆ removeSections() [3/3]

◆ removeAll()

◆ storedSectionCount()

◆ atCycleBoundary()

◆ reset()

◆ display()

◆ sectionProvider()

◆ atSectionBoundary()

◆ sectionCount()

◆ allowHeaderSplit()

◆ headerSplitAllowed()

◆ getNextPacket()

◆ setPID()

◆ getPID()

◆ setNextContinuityCounter()

◆ nextContinuityCounter()

◆ packetCount()

◆ report()

◆ duck()

◆ configurePacket()