FLV::Tag Class Reference

This class is used to hold, work with and get information about a single FLV tag. More...

#include <flv_tag.h>

Public Member Functions
	Tag ()
	Constructor for a new, empty, tag. More...
	Tag ()
	Constructor for a new, empty, tag. More...
	Tag (const Tag &O)
	Copy constructor, copies the contents of an existing tag. More...
	Tag (const Tag &O)
	Copy constructor, copies the contents of an existing tag. More...
	Tag (const RTMPStream::Chunk &O)
	Copy constructor from a RTMP chunk. More...
	Tag (const RTMPStream::Chunk &O)
	Copy constructor from a RTMP chunk. More...
	~Tag ()
	Generic destructor. More...
	~Tag ()
	Generic destructor. More...
bool	ChunkLoader (const RTMPStream::Chunk &O)
bool	ChunkLoader (const RTMPStream::Chunk &O)
	FLV loader function from chunk. More...
bool	DTSCAudioInit (DTSC::Track &audio)
	FLV Audio init data loader function from JSON. More...
bool	DTSCAudioInit (DTSC::Track &audio)
bool	DTSCLoader (DTSC::Packet &packData, DTSC::Track &track)
bool	DTSCLoader (DTSC::Packet &packData, DTSC::Track &track)
bool	DTSCMetaInit (DTSC::Meta &M, std::set< long unsigned int > &selTracks)
bool	DTSCMetaInit (DTSC::Meta &M, std::set< long unsigned int > &selTracks)
bool	DTSCVideoInit (DTSC::Track &video)
	FLV Video init data loader function from JSON. More...
bool	DTSCVideoInit (DTSC::Track &video)
bool	FileLoader (FILE *f)
	Try to load a tag from a file. More...
bool	FileLoader (FILE *f)
const char *	getAudioCodec ()
	Returns a c-string with the audio codec name. More...
const char *	getAudioCodec ()
	Returns a c-string with the audio codec name. More...
char *	getData ()
	Returns a pointer to the raw media data for this packet. More...
char *	getData ()
unsigned int	getDataLen ()
	Returns the length of the raw media data for this packet. More...
unsigned int	getDataLen ()
unsigned int	getTrackID ()
	Returns 1 for video, 2 for audio, 3 for meta, 0 otherwise. More...
unsigned int	getTrackID ()
const char *	getVideoCodec ()
	Returns a c-string with the video codec name. More...
const char *	getVideoCodec ()
	Returns a c-string with the video codec name. More...
bool	isInitData ()
	True if current tag is init data for this media type. More...
bool	isInitData ()
	True if current tag is init data for this media type. More...
bool	MemLoader (char *D, unsigned int S, unsigned int &P)
	Try to load a tag from a data buffer in memory. More...
bool	MemLoader (char *D, unsigned int S, unsigned int &P)
bool	needsInitData ()
	True if this media type requires init data. More...
bool	needsInitData ()
	True if this media type requires init data. More...
int	offset ()
	Returns the 24-bit offset of this tag. More...
int	offset ()
void	offset (int o)
void	offset (int o)
	Sets the 24-bit offset of this tag. More...
Tag &	operator= (const Tag &O)
	Assignment operator - works exactly like the copy constructor. More...
Tag &	operator= (const Tag &O)
	Assignment operator - works exactly like the copy constructor. More...
unsigned int	tagTime ()
unsigned int	tagTime ()
	Returns the 32-bit timestamp of this tag. More...
void	tagTime (unsigned int T)
	Sets the 32-bit timestamp of this tag. More...
void	tagTime (unsigned int T)
std::string	tagType ()
	Returns a std::string describing the tag in detail. More...
std::string	tagType ()
	Returns a std::string describing the tag in detail. More...
JSON::Value	toJSON (DTSC::Meta &metadata, AMF::Object &amf_storage, unsigned int reTrack=0)
JSON::Value	toJSON (DTSC::Meta &metadata, AMF::Object &amf_storage, unsigned int reTrack=0)

Data Fields
char *	data
	Pointer to tag buffer. More...
bool	isKeyframe
	True if current tag is a video keyframe. More...
int	len
	Actual length of tag. More...

Protected Member Functions
bool	checkBufferSize ()
	Checks if buf is large enough to contain len. More...
bool	checkBufferSize ()
bool	FileReadUntil (char *buffer, unsigned int count, unsigned int &sofar, FILE *f)
	Helper function for FLV::FileLoader. More...
bool	FileReadUntil (char *buffer, unsigned int count, unsigned int &sofar, FILE *f)
bool	MemReadUntil (char *buffer, unsigned int count, unsigned int &sofar, char *D, unsigned int S, unsigned int &P)
bool	MemReadUntil (char *buffer, unsigned int count, unsigned int &sofar, char *D, unsigned int S, unsigned int &P)
	Helper function for FLV::MemLoader. More...
bool	Meta_Has (JSON::Value &meta, std::string cat, std::string elem)
bool	Meta_Has (JSON::Value &meta, std::string cat, std::string elem)
void	Meta_Put (JSON::Value &meta, std::string cat, std::string elem, std::string val)
void	Meta_Put (JSON::Value &meta, std::string cat, std::string elem, std::string val)
void	Meta_Put (JSON::Value &meta, std::string cat, std::string elem, uint64_t val)
void	Meta_Put (JSON::Value &meta, std::string cat, std::string elem, uint64_t val)
void	setLen ()
void	setLen ()
	Helper function that properly sets the tag length from the internal len variable. More...

Protected Attributes
int	buf
	Maximum length of buffer space. More...
bool	done
	Body reading done? More...
unsigned int	sofar
	How many bytes are read sofar? More...

Detailed Description

This class is used to hold, work with and get information about a single FLV tag.

Constructor & Destructor Documentation

FLV::Tag::Tag

(

)

Constructor for a new, empty, tag.

The buffer length is initialized to 0, and later automatically increased if neccesary.

FLV::Tag::Tag

(

const Tag &

O

)

Copy constructor, copies the contents of an existing tag.

The buffer length is initialized to the actual size of the tag that is being copied, and later automaticallt increased if neccesary.

FLV::Tag::Tag

(

const RTMPStream::Chunk &

O

)

Copy constructor from a RTMP chunk.

Copies the contents of a RTMP chunk into a valid FLV tag. Exactly the same as making a chunk by through the default (empty) constructor and then calling FLV::Tag::ChunkLoader with the chunk as argument.

FLV::Tag::~Tag

(

)

Generic destructor.

Generic destructor that frees the allocated memory in the internal data variable, if any.

FLV::Tag::Tag

(

)

Constructor for a new, empty, tag.

FLV::Tag::Tag

(

const Tag &

O

)

Copy constructor, copies the contents of an existing tag.

FLV::Tag::Tag

(

const RTMPStream::Chunk &

O

)

Copy constructor from a RTMP chunk.

FLV::Tag::~Tag

(

)

Generic destructor.

Member Function Documentation

bool FLV::Tag::checkBufferSize ( )

protected

Checks if buf is large enough to contain len.

Attempts to resize data buffer if not/

Returns

True if buffer is large enough, false otherwise.

bool FLV::Tag::checkBufferSize ( )

protected

bool FLV::Tag::ChunkLoader

(

const RTMPStream::Chunk &

O

)

FLV loader function from chunk.

Copies the contents and wraps it in a FLV header.

bool FLV::Tag::ChunkLoader

(

const RTMPStream::Chunk &

O

)

bool FLV::Tag::DTSCAudioInit

(

DTSC::Track &

audio

)

bool FLV::Tag::DTSCAudioInit

(

DTSC::Track &

audio

)

FLV Audio init data loader function from JSON.

bool FLV::Tag::DTSCLoader	(	DTSC::Packet &	packData,
		DTSC::Track &	track
	)

bool FLV::Tag::DTSCLoader	(	DTSC::Packet &	packData,
		DTSC::Track &	track
	)

bool FLV::Tag::DTSCMetaInit	(	DTSC::Meta &	M,
		std::set< long unsigned int > &	selTracks
	)

bool FLV::Tag::DTSCMetaInit	(	DTSC::Meta &	M,
		std::set< long unsigned int > &	selTracks
	)

bool FLV::Tag::DTSCVideoInit

(

DTSC::Track &

video

)

bool FLV::Tag::DTSCVideoInit

(

DTSC::Track &

video

)

FLV Video init data loader function from JSON.

bool FLV::Tag::FileLoader

(

FILE *

f

)

Try to load a tag from a file.

This is a stateful function - if fed incorrect data, it will most likely never return true again! While this function returns false, the Tag might not contain valid data.

Parameters

f	The file to read from.

Returns

True if a whole tag is succesfully read, false otherwise.

bool FLV::Tag::FileLoader

(

FILE *

f

)

bool FLV::Tag::FileReadUntil ( char *  buffer, unsigned int  count, unsigned int &  sofar, FILE *  f  )

protected

Helper function for FLV::FileLoader.

This function will try to read count bytes from file f into buffer. This function should be called repeatedly until true.

Parameters

buffer	The target buffer.
count	Amount of bytes to read.
sofar	Current amount read.
f	File to read from.

Returns

True if count bytes are read succesfully, false otherwise.

bool FLV::Tag::FileReadUntil ( char *  buffer, unsigned int  count, unsigned int &  sofar, FILE *  f  )

protected

const char * FLV::Tag::getAudioCodec

(

)

Returns a c-string with the audio codec name.

const char* FLV::Tag::getAudioCodec

(

)

Returns a c-string with the audio codec name.

char * FLV::Tag::getData

(

)

Returns a pointer to the raw media data for this packet.

char* FLV::Tag::getData

(

)

unsigned int FLV::Tag::getDataLen

(

)

unsigned int FLV::Tag::getDataLen

(

)

Returns the length of the raw media data for this packet.

unsigned int FLV::Tag::getTrackID

(

)

Returns 1 for video, 2 for audio, 3 for meta, 0 otherwise.

unsigned int FLV::Tag::getTrackID

(

)

const char* FLV::Tag::getVideoCodec

(

)

Returns a c-string with the video codec name.

const char * FLV::Tag::getVideoCodec

(

)

Returns a c-string with the video codec name.

bool FLV::Tag::isInitData

(

)

True if current tag is init data for this media type.

bool FLV::Tag::isInitData

(

)

True if current tag is init data for this media type.

bool FLV::Tag::MemLoader	(	char *	D,
		unsigned int	S,
		unsigned int &	P
	)

Try to load a tag from a data buffer in memory.

This is a stateful function - if fed incorrect data, it will most likely never return true again! While this function returns false, the Tag might not contain valid data.

Parameters

D	The location of the data buffer.
S	The size of the data buffer.
P	The current position in the data buffer. Will be updated to reflect new position.

Returns

True if a whole tag is succesfully read, false otherwise.

bool FLV::Tag::MemLoader	(	char *	D,
		unsigned int	S,
		unsigned int &	P
	)

bool FLV::Tag::MemReadUntil ( char *  buffer, unsigned int  count, unsigned int &  sofar, char *  D, unsigned int  S, unsigned int &  P  )

protected

Helper function for FLV::MemLoader.

This function will try to read count bytes from data buffer D into buffer. This function should be called repeatedly until true. P and sofar are not the same value, because D may not start with the current tag.

Parameters

buffer	The target buffer.
count	Amount of bytes to read.
sofar	Current amount read.
D	The location of the data buffer.
S	The size of the data buffer.
P	The current position in the data buffer. Will be updated to reflect new position.

Returns

True if count bytes are read succesfully, false otherwise.

bool FLV::Tag::MemReadUntil ( char *  buffer, unsigned int  count, unsigned int &  sofar, char *  D, unsigned int  S, unsigned int &  P  )

protected

bool FLV::Tag::Meta_Has ( JSON::Value &  meta, std::string  cat, std::string  elem  )

protected

bool FLV::Tag::Meta_Has ( JSON::Value &  meta, std::string  cat, std::string  elem  )

protected

void FLV::Tag::Meta_Put ( JSON::Value &  meta, std::string  cat, std::string  elem, std::string  val  )

protected

void FLV::Tag::Meta_Put ( JSON::Value &  meta, std::string  cat, std::string  elem, std::string  val  )

protected

void FLV::Tag::Meta_Put ( JSON::Value &  meta, std::string  cat, std::string  elem, uint64_t  val  )

protected

void FLV::Tag::Meta_Put ( JSON::Value &  meta, std::string  cat, std::string  elem, uint64_t  val  )

protected

bool FLV::Tag::needsInitData

(

)

True if this media type requires init data.

Will always return false if the tag type is not 0x08 or 0x09. Returns true for H263, AVC (H264), AAC.

Todo:

Check if MP3 does or does not require init data...

bool FLV::Tag::needsInitData

(

)

True if this media type requires init data.

int FLV::Tag::offset

(

)

Returns the 24-bit offset of this tag.

Returns 0 if the tag isn't H264

int FLV::Tag::offset

(

)

void FLV::Tag::offset

(

int

o

)

Sets the 24-bit offset of this tag.

Ignored if the tag isn't H264

void FLV::Tag::offset

(

int

o

)

Tag& FLV::Tag::operator=

(

const Tag &

O

)

Assignment operator - works exactly like the copy constructor.

FLV::Tag & FLV::Tag::operator=

(

const Tag &

O

)

Assignment operator - works exactly like the copy constructor.

This operator checks for self-assignment.

void FLV::Tag::setLen ( )

protected

void FLV::Tag::setLen ( )

protected

Helper function that properly sets the tag length from the internal len variable.

unsigned int FLV::Tag::tagTime

(

)

unsigned int FLV::Tag::tagTime

(

)

Returns the 32-bit timestamp of this tag.

void FLV::Tag::tagTime

(

unsigned int

T

)

void FLV::Tag::tagTime

(

unsigned int

T

)

Sets the 32-bit timestamp of this tag.

std::string FLV::Tag::tagType

(

)

Returns a std::string describing the tag in detail.

The string includes information about whether the tag is audio, video or metadata, what encoding is used, and the details of the encoding itself.

std::string FLV::Tag::tagType

(

)

Returns a std::string describing the tag in detail.

JSON::Value FLV::Tag::toJSON	(	DTSC::Meta &	metadata,
		AMF::Object &	amf_storage,
		unsigned int	reTrack = 0
	)

JSON::Value FLV::Tag::toJSON	(	DTSC::Meta &	metadata,
		AMF::Object &	amf_storage,
		unsigned int	reTrack = 0
	)

Field Documentation

int FLV::Tag::buf

protected

Maximum length of buffer space.

char * FLV::Tag::data

Pointer to tag buffer.

bool FLV::Tag::done

protected

Body reading done?

bool FLV::Tag::isKeyframe

True if current tag is a video keyframe.

int FLV::Tag::len

Actual length of tag.

unsigned int FLV::Tag::sofar

protected

How many bytes are read sofar?

---

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

• lib/flv_tag.h
• lib/flv_tag.cpp