Communicating with remote peer via the network. More...

Data Structures
struct	pjmedia_stream_info

struct	pjmedia_stream_dtmf_event

Typedefs
typedef struct pjmedia_channel	pjmedia_channel

Enumerations
enum	pjmedia_stream_dtmf_event_flags { PJMEDIA_STREAM_DTMF_IS_UPDATE = (1 << 0) , PJMEDIA_STREAM_DTMF_IS_END = (1 << 1) }

Functions
pj_status_t	pjmedia_stream_info_from_sdp (pjmedia_stream_info si, pj_pool_t pool, pjmedia_endpt endpt, const pjmedia_sdp_session local, const pjmedia_sdp_session *remote, unsigned stream_idx)

pj_status_t	pjmedia_stream_create (pjmedia_endpt endpt, pj_pool_t pool, const pjmedia_stream_info info, pjmedia_transport tp, void user_data, pjmedia_stream *p_stream)

pj_status_t	pjmedia_stream_destroy (pjmedia_stream *stream)

char	pjmedia_stream_get_last_jb_frame_type (pjmedia_stream *stream)

pj_status_t	pjmedia_stream_get_port (pjmedia_stream stream, pjmedia_port *p_port)

pjmedia_transport *	pjmedia_stream_get_transport (pjmedia_stream *st)

pj_status_t	pjmedia_stream_start (pjmedia_stream *stream)

pj_status_t	pjmedia_stream_modify_codec_param (pjmedia_stream stream, const pjmedia_codec_param param)

pj_status_t	pjmedia_stream_get_info (const pjmedia_stream stream, pjmedia_stream_info info)

pj_status_t	pjmedia_stream_get_stat (const pjmedia_stream stream, pjmedia_rtcp_stat stat)

pj_status_t	pjmedia_stream_reset_stat (pjmedia_stream *stream)

pj_status_t	pjmedia_stream_get_stat_jbuf (const pjmedia_stream stream, pjmedia_jb_state state)

pj_status_t	pjmedia_stream_pause (pjmedia_stream *stream, pjmedia_dir dir)

pj_status_t	pjmedia_stream_resume (pjmedia_stream *stream, pjmedia_dir dir)

pj_status_t	pjmedia_stream_dial_dtmf (pjmedia_stream stream, const pj_str_t ascii_digit)

pj_bool_t	pjmedia_stream_check_dtmf (pjmedia_stream *stream)

pj_status_t	pjmedia_stream_get_dtmf (pjmedia_stream stream, char ascii_digits, unsigned *size)

pj_status_t	pjmedia_stream_set_dtmf_callback (pjmedia_stream stream, void(cb)(pjmedia_stream , void user_data, int digit), void *user_data)

pj_status_t	pjmedia_stream_set_dtmf_event_callback (pjmedia_stream stream, void(cb)(pjmedia_stream , void user_data, const pjmedia_stream_dtmf_event event), void user_data)

pj_status_t	pjmedia_stream_send_rtcp_sdes (pjmedia_stream *stream)

pj_status_t	pjmedia_stream_send_rtcp_bye (pjmedia_stream *stream)

pj_status_t	pjmedia_stream_get_rtp_session_info (pjmedia_stream stream, pjmedia_stream_rtp_sess_info session_info)

Detailed Description

A media stream is a bidirectional multimedia communication between two endpoints. It corresponds to a media description (m= line) in SDP session descriptor.

A media stream consists of two unidirectional channels:

encoding channel, which transmits unidirectional media to remote, and
decoding channel, which receives unidirectional media from remote.

A media stream exports media port interface (see Media Ports Framework) and application normally uses this interface to interconnect the stream to other PJMEDIA components.

A media stream internally manages the following objects:

an instance of media codec (see Codec Framework),
an Adaptive jitter buffer,
two instances of RTP sessions (pjmedia_rtp_session, one for each direction),
one instance of RTCP session (pjmedia_rtcp_session),
and a reference to media transport to send and receive packets to/from the network (see Media Transport).

Streams are created by calling pjmedia_stream_create(), specifying pjmedia_stream_info structure in the parameter. Application can construct the pjmedia_stream_info structure manually, or use pjmedia_stream_info_from_sdp() or pjmedia_session_info_from_sdp() functions to construct the pjmedia_stream_info from local and remote SDP session descriptors.

Application can also use Media Sessions to indirectly create the streams.

Typedef Documentation

◆ pjmedia_channel

typedef struct pjmedia_channel pjmedia_channel

Opaque declaration for media channel. Media channel is unidirectional flow of media from sender to receiver.

Enumeration Type Documentation

◆ pjmedia_stream_dtmf_event_flags

enum pjmedia_stream_dtmf_event_flags

This enumeration defines flags used by pjmedia_stream_dtmf_event.

Enumerator
PJMEDIA_STREAM_DTMF_IS_UPDATE	The event was already indicated earlier. The new indication contains an updated event duration.
PJMEDIA_STREAM_DTMF_IS_END	The event has ended and the indication contains the final event duration. Note that end indications might get lost. Hence it is not guaranteed to receive an event with PJMEDIA_STREAM_DTMF_IS_END for every event.

Function Documentation

◆ pjmedia_stream_info_from_sdp()

pj_status_t pjmedia_stream_info_from_sdp	(	pjmedia_stream_info *	si,
		pj_pool_t *	pool,
		pjmedia_endpt *	endpt,
		const pjmedia_sdp_session *	local,
		const pjmedia_sdp_session *	remote,
		unsigned	stream_idx
	)

This function will initialize the stream info based on information in both SDP session descriptors for the specified stream index. The remaining information will be taken from default codec parameters. If socket info array is specified, the socket will be copied to the session info as well.

Parameters

si	Stream info structure to be initialized.
pool	Pool to allocate memory.
endpt	PJMEDIA endpoint instance.
local	Local SDP session descriptor.
remote	Remote SDP session descriptor.
stream_idx	Media stream index in the session descriptor.

Returns: PJ_SUCCESS if stream info is successfully initialized.

◆ pjmedia_stream_create()

pj_status_t pjmedia_stream_create	(	pjmedia_endpt *	endpt,
		pj_pool_t *	pool,
		const pjmedia_stream_info *	info,
		pjmedia_transport *	tp,
		void *	user_data,
		pjmedia_stream **	p_stream
	)

Create a media stream based on the specified parameter. After the stream has been created, application normally would want to get the media port interface of the streams, by calling pjmedia_stream_get_port(). The media port interface exports put_frame() and get_frame() function, used to transmit and receive media frames from the stream.

Without application calling put_frame() and get_frame(), there will be no media frames transmitted or received by the stream.

Parameters

endpt	Media endpoint.
pool	Pool to allocate memory for the stream. A large number of memory may be needed because jitter buffer needs to preallocate some storage.
info	Stream information.
tp	Stream transport instance used to transmit and receive RTP/RTCP packets to/from the underlying transport.
user_data	Arbitrary user data (for future callback feature).
p_stream	Pointer to receive the media stream.

Returns: PJ_SUCCESS on success.

◆ pjmedia_stream_destroy()

pj_status_t pjmedia_stream_destroy ( pjmedia_stream * stream )

Destroy the media stream.

Parameters

stream The media stream.

Returns: PJ_SUCCESS on success.

◆ pjmedia_stream_get_last_jb_frame_type()

char pjmedia_stream_get_last_jb_frame_type ( pjmedia_stream * stream )

Get the last frame type retreived from the jitter buffer.

Parameters

stream The media stream.

Returns: Jitter buffer frame type.

◆ pjmedia_stream_get_port()

pj_status_t pjmedia_stream_get_port	(	pjmedia_stream *	stream,
		pjmedia_port **	p_port
	)

Get the media port interface of the stream. The media port interface declares put_frame() and get_frame() function, which is the only way for application to transmit and receive media frames from the stream.

Parameters

stream	The media stream.
p_port	Pointer to receive the port interface.

Returns: PJ_SUCCESS on success.

◆ pjmedia_stream_get_transport()

pjmedia_transport * pjmedia_stream_get_transport ( pjmedia_stream * st )

Get the media transport object associated with this stream.

Parameters

st	The media stream.

Returns: The transport object being used by the stream.

◆ pjmedia_stream_start()

pj_status_t pjmedia_stream_start ( pjmedia_stream * stream )

Start the media stream. This will start the appropriate channels in the media stream, depending on the media direction that was set when the stream was created.

Parameters

stream The media stream.

Returns: PJ_SUCCESS on success.

◆ pjmedia_stream_modify_codec_param()

pj_status_t pjmedia_stream_modify_codec_param	(	pjmedia_stream *	stream,
		const pjmedia_codec_param *	param
	)

Modify the stream's codec parameter after the codec is opened. Note that not all codec parameters can be modified during run-time. Currently, only Opus codec supports changing key codec parameters such as bitrate and bandwidth, while other codecs may only be able to modify minor settings such as VAD or PLC.

Parameters

stream	The media stream.
param	The new codec parameter.

Returns: PJ_SUCCESS on success.

◆ pjmedia_stream_get_info()

pj_status_t pjmedia_stream_get_info	(	const pjmedia_stream *	stream,
		pjmedia_stream_info *	info
	)

Get the stream info.

Parameters

stream	The media stream.
info	Stream info.

Returns: PJ_SUCCESS on success.

◆ pjmedia_stream_get_stat()

pj_status_t pjmedia_stream_get_stat	(	const pjmedia_stream *	stream,
		pjmedia_rtcp_stat *	stat
	)

Get the stream statistics. See also pjmedia_stream_get_stat_jbuf()

Parameters

stream	The media stream.
stat	Media stream statistics.

Returns: PJ_SUCCESS on success.

◆ pjmedia_stream_reset_stat()

pj_status_t pjmedia_stream_reset_stat ( pjmedia_stream * stream )

Reset the stream statistics.

Parameters

stream The media stream.

Returns: PJ_SUCCESS on success.

◆ pjmedia_stream_get_stat_jbuf()

pj_status_t pjmedia_stream_get_stat_jbuf	(	const pjmedia_stream *	stream,
		pjmedia_jb_state *	state
	)

Get current jitter buffer state. See also pjmedia_stream_get_stat()

Parameters

stream	The media stream.
state	Jitter buffer state.

Returns: PJ_SUCCESS on success.

◆ pjmedia_stream_pause()

pj_status_t pjmedia_stream_pause	(	pjmedia_stream *	stream,
		pjmedia_dir	dir
	)

Pause the individual channel in the stream.

Parameters

stream	The media channel.
dir	Which direction to pause.

Returns: PJ_SUCCESS on success.

◆ pjmedia_stream_resume()

pj_status_t pjmedia_stream_resume	(	pjmedia_stream *	stream,
		pjmedia_dir	dir
	)

Resume the individual channel in the stream.

Parameters

stream	The media channel.
dir	Which direction to resume.

Returns: PJ_SUCCESS on success;

◆ pjmedia_stream_dial_dtmf()

pj_status_t pjmedia_stream_dial_dtmf	(	pjmedia_stream *	stream,
		const pj_str_t *	ascii_digit
	)

Transmit DTMF to this stream. The DTMF will be transmitted uisng RTP telephone-events as described in RFC 2833. This operation is only valid for audio stream.

Parameters

stream	The media stream.
ascii_digit	String containing digits to be sent to remote as described on RFC 2833 section 3.10. If PJMEDIA_HAS_DTMF_FLASH is enabled, character 'R' is used to represent the event type 16 (flash) as stated in RFC 4730. Currently the maximum number of digits are 32.

Returns: PJ_SUCCESS on success.

◆ pjmedia_stream_check_dtmf()

pj_bool_t pjmedia_stream_check_dtmf ( pjmedia_stream * stream )

Check if the stream has incoming DTMF digits in the incoming DTMF queue. Incoming DTMF digits received via RFC 2833 mechanism are saved in the incoming digits queue.

Parameters

stream The media stream.

Returns: Non-zero (PJ_TRUE) if the stream has received DTMF digits in the .

◆ pjmedia_stream_get_dtmf()

pj_status_t pjmedia_stream_get_dtmf	(	pjmedia_stream *	stream,
		char *	ascii_digits,
		unsigned *	size
	)

Retrieve the incoming DTMF digits from the stream, and remove the digits from stream's DTMF buffer. Note that the digits buffer will not be NULL terminated.

Parameters

stream	The media stream.
ascii_digits	Buffer to receive the digits. The length of this buffer is indicated in the "size" argument.
size	On input, contains the maximum digits to be copied to the buffer. On output, it contains the actual digits that has been copied to the buffer.

Returns: Non-zero (PJ_TRUE) if the stream has received DTMF digits in the .

◆ pjmedia_stream_set_dtmf_callback()

pj_status_t pjmedia_stream_set_dtmf_callback	(	pjmedia_stream *	stream,
		void()(pjmedia_stream , void *user_data, int digit)	cb,
		void *	user_data
	)

Set callback to be called upon receiving DTMF digits. If callback is registered, the stream will not buffer incoming DTMF but rather call the callback as soon as DTMF digit is received completely. This callback will not be called if another callback is set via pjmedia_stream_set_dtmf_event_callback() as well.

Parameters

stream	The media stream.
cb	Callback to be called upon receiving DTMF digits. The DTMF digits will be given to the callback as ASCII digits.
user_data	User data to be returned back when the callback is called.

Returns: PJ_SUCCESS on success.

◆ pjmedia_stream_set_dtmf_event_callback()

pj_status_t pjmedia_stream_set_dtmf_event_callback	(	pjmedia_stream *	stream,
		void()(pjmedia_stream , void user_data, const pjmedia_stream_dtmf_event event)	cb,
		void *	user_data
	)

Set callback to be called upon receiving DTMF digits. If callback is registered, the stream will not buffer incoming DTMF but rather call the callback as soon as DTMF digit is received.

Parameters

stream	The media stream.
cb	Callback to be called upon receiving DTMF digits. See pjmedia_stream_dtmf_event.
user_data	User data to be returned back when the callback is called.

Returns: PJ_SUCCESS on success.

◆ pjmedia_stream_send_rtcp_sdes()

pj_status_t pjmedia_stream_send_rtcp_sdes ( pjmedia_stream * stream )

Send RTCP SDES for the media stream.

Parameters

stream The media stream.

Returns: PJ_SUCCESS on success.

◆ pjmedia_stream_send_rtcp_bye()

pj_status_t pjmedia_stream_send_rtcp_bye ( pjmedia_stream * stream )

Send RTCP BYE for the media stream.

Parameters

stream The media stream.

Returns: PJ_SUCCESS on success.

◆ pjmedia_stream_get_rtp_session_info()

pj_status_t pjmedia_stream_get_rtp_session_info	(	pjmedia_stream *	stream,
		pjmedia_stream_rtp_sess_info *	session_info
	)

Get the RTP session information of the media stream. This function can be useful for app with custom media transport to inject/filter some outgoing/incoming proprietary packets into normal audio RTP traffics. This will return the original pointer to the internal states of the stream, and generally it is not advisable for app to modify them.

Parameters

stream	The media stream.
session_info	The stream session info.

Returns: PJ_SUCCESS on success.

Data Structures

Typedefs

Enumerations

Functions

Detailed Description

Typedef Documentation

◆ pjmedia_channel

Enumeration Type Documentation

◆ pjmedia_stream_dtmf_event_flags

Function Documentation

◆ pjmedia_stream_info_from_sdp()

◆ pjmedia_stream_create()

◆ pjmedia_stream_destroy()

◆ pjmedia_stream_get_last_jb_frame_type()

◆ pjmedia_stream_get_port()

◆ pjmedia_stream_get_transport()

◆ pjmedia_stream_start()

◆ pjmedia_stream_modify_codec_param()

◆ pjmedia_stream_get_info()

◆ pjmedia_stream_get_stat()

◆ pjmedia_stream_reset_stat()

◆ pjmedia_stream_get_stat_jbuf()

◆ pjmedia_stream_pause()

◆ pjmedia_stream_resume()

◆ pjmedia_stream_dial_dtmf()

◆ pjmedia_stream_check_dtmf()

◆ pjmedia_stream_get_dtmf()

◆ pjmedia_stream_set_dtmf_callback()

◆ pjmedia_stream_set_dtmf_event_callback()

◆ pjmedia_stream_send_rtcp_sdes()

◆ pjmedia_stream_send_rtcp_bye()

◆ pjmedia_stream_get_rtp_session_info()