RTSPMediaCallbackSource Class Reference

Callback-based RTSP Media Source. More...

#include <RTSPMediaCallbackSource.h>

Inheritance diagram for RTSPMediaCallbackSource:

Public Types
typedef void(*	lifecycle_callback_t) (void *userData)
typedef int(*	packet_size_callback_t) (void *userData)
typedef int(*	read_callback_t) (uint8_t *buffer, int maxBytes, void *userData)

Public Member Functions
	RTSPMediaCallbackSource ()
	Default constructor.
	RTSPMediaCallbackSource (read_callback_t callback, void *userData=nullptr)
	Constructor with read callback.
	RTSPMediaCallbackSource (RTSPFormat &format, read_callback_t callback, void *userData=nullptr)
	Constructor with format and read callback.
virtual	~RTSPMediaCallbackSource ()
RTSPFormat &	getFormat () override
	Get the current RTSP format configuration.
void *	getUserData () const
	Get the user data pointer.
bool	isActive () const
	Check if the source is active.
int	packetSize () override
	Report the size of the next queued fragment via the configured packet-size callback (packetized/video sources only)
int	readBytes (void *dest, int maxBytes) override
	Read media data using the configured callback.
void	setFormat (RTSPFormat &format)
	Set the RTSP format configuration.
void	setPacketSizeCallback (packet_size_callback_t callback)
	Set the callback reporting the size of the next already- fragmented, ready-to-send packet. Configuring this switches packetSize() from the default "not packetized" (-1) to forwarding the callback's result, which in turn switches RTSPMediaStreamer to the packetized send path (see IMediaSource::packetSize()) - use this for video sources whose fragmentation/RTP payload framing is done externally (e.g. by an H264RtpEncoder/JPEGRtpEncoder that the read callback pulls from).
void	setReadCallback (read_callback_t callback, void *userData=nullptr)
	Set the callback function for reading media data.
void	setStartCallback (lifecycle_callback_t callback)
	Set optional start callback (called when streaming begins)
void	setStopCallback (lifecycle_callback_t callback)
	Set optional stop callback (called when streaming ends)
void	start () override
	Start the media source Calls the optional start callback if configured.
void	stop () override
	Stop the media source Calls the optional stop callback if configured.

Protected Attributes
RTSPFormatPCM	default_format
bool	is_active
RTSPFormat *	p_format
packet_size_callback_t	packet_size_callback
read_callback_t	read_callback
lifecycle_callback_t	start_callback
lifecycle_callback_t	stop_callback
void *	user_data

Detailed Description

Callback-based RTSP Media Source.

RTSPMediaCallbackSource provides a flexible way to stream custom media data over RTSP by using user-provided callback functions. This is ideal for:

• Custom audio/video sources that don't fit the Stream interface
• Hardware-specific media capture (cameras, microphones, etc.)
• Generated content (synthetic audio, test patterns, etc.)
• Integration with existing media libraries or codecs

The callback approach allows maximum flexibility while maintaining compatibility with the RTSP streaming framework.

Author

Phil Schatzmann

Member Typedef Documentation

lifecycle_callback_t

typedef void(* lifecycle_callback_t) (void *userData)

Callback function type for source lifecycle management

Parameters

userData

Optional user data pointer passed to callback

packet_size_callback_t

typedef int(* packet_size_callback_t) (void *userData)

Callback function type for reporting the size of the next queued, ready-to-send fragment - only needed for packetized (video) sources that hand out already RTP-payload-ready fragments (e.g. H264RtpEncoder, JPEGRtpEncoder) instead of a plain byte stream. See IMediaSource::packetSize() for the exact contract.

Parameters

userData

Optional user data pointer passed to callback

Returns

0 if packetized but nothing queued right now, otherwise the size in bytes of the next fragment

read_callback_t

typedef int(* read_callback_t) (uint8_t *buffer, int maxBytes, void *userData)

Callback function type for reading media data

Parameters

buffer	Buffer to write media data to
maxBytes	Maximum number of bytes to write
userData	Optional user data pointer passed to callback

Returns

Number of bytes written (0 = no data available, -1 = error)

Constructor & Destructor Documentation

RTSPMediaCallbackSource() [1/3]

RTSPMediaCallbackSource ( )

inline

Default constructor.

RTSPMediaCallbackSource() [2/3]

RTSPMediaCallbackSource ( read_callback_t  callback, void *  userData = nullptr  )

inline

Constructor with read callback.

Parameters

callback	Function to call for reading media data
userData	Optional pointer passed to callbacks

RTSPMediaCallbackSource() [3/3]

RTSPMediaCallbackSource ( RTSPFormat &  format, read_callback_t  callback, void *  userData = nullptr  )

inline

Constructor with format and read callback.

Parameters

format	RTSPFormat configuration for the media stream
callback	Function to call for reading media data
userData	Optional pointer passed to callbacks

~RTSPMediaCallbackSource()

virtual ~RTSPMediaCallbackSource ( )

inlinevirtual

Member Function Documentation

getFormat()

RTSPFormat & getFormat ( )

inlineoverridevirtual

Get the current RTSP format configuration.

Returns

Reference to the format configuration

Implements IMediaSource.

getUserData()

void * getUserData ( ) const

inline

Get the user data pointer.

Returns

Pointer passed to callbacks

isActive()

bool isActive ( ) const

inline

Check if the source is active.

Returns

true if started and callback is configured

packetSize()

int packetSize ( )

inlineoverridevirtual

Report the size of the next queued fragment via the configured packet-size callback (packetized/video sources only)

Returns

-1 if no packet-size callback is configured (falls back to the generic byte-stream path in RTSPMediaStreamer), 0 if packetized but nothing is queued right now, otherwise the size of the next fragment

Reimplemented from IMediaSource.

readBytes()

int readBytes ( void *  dest, int  maxBytes  )

inlineoverridevirtual

Read media data using the configured callback.

Parameters

dest	Buffer to receive media data
maxBytes	Maximum number of bytes to read

Returns

Number of bytes actually read

Implements IMediaSource.

setFormat()

void setFormat ( RTSPFormat &  format )

inline

Set the RTSP format configuration.

Parameters

format

Format configuration for the media stream

setPacketSizeCallback()

void setPacketSizeCallback ( packet_size_callback_t  callback )

inline

Set the callback reporting the size of the next already- fragmented, ready-to-send packet. Configuring this switches packetSize() from the default "not packetized" (-1) to forwarding the callback's result, which in turn switches RTSPMediaStreamer to the packetized send path (see IMediaSource::packetSize()) - use this for video sources whose fragmentation/RTP payload framing is done externally (e.g. by an H264RtpEncoder/JPEGRtpEncoder that the read callback pulls from).

Parameters

callback

Function that reports the next fragment's size

setReadCallback()

void setReadCallback ( read_callback_t  callback, void *  userData = nullptr  )

inline

Set the callback function for reading media data.

Parameters

callback	Function that provides media data
userData	Optional pointer passed to the callback

setStartCallback()

void setStartCallback ( lifecycle_callback_t  callback )

inline

Set optional start callback (called when streaming begins)

Parameters

callback

Function called during start()

setStopCallback()

void setStopCallback ( lifecycle_callback_t  callback )

inline

Set optional stop callback (called when streaming ends)

Parameters

callback

Function called during stop()

start()

void start ( )

inlineoverridevirtual

Start the media source Calls the optional start callback if configured.

Reimplemented from IMediaSource.

stop()

void stop ( )

inlineoverridevirtual

Stop the media source Calls the optional stop callback if configured.

Reimplemented from IMediaSource.

Member Data Documentation

default_format

RTSPFormatPCM default_format

protected

is_active

bool is_active

protected

p_format

RTSPFormat* p_format

protected

packet_size_callback

packet_size_callback_t packet_size_callback

protected

read_callback

read_callback_t read_callback

protected

start_callback

lifecycle_callback_t start_callback

protected

stop_callback

lifecycle_callback_t stop_callback

protected

user_data

void* user_data

protected

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

• src/AudioTools/Communication/RTSP/RTSPMediaCallbackSource.h