Node

Files
file	command.h
	spa/node/command.h
file	event.h
	spa/node/event.h
file	io.h
	spa/node/io.h
file	keys.h
	spa/node/keys.h
file	node.h
	spa/node/node.h
file	type-info.h
	spa/node/type-info.h

Data Structures
struct	spa_io_buffers
	IO area to exchange buffers. More...
struct	spa_io_memory
	IO area to exchange a memory region. More...
struct	spa_io_range
	A range, suitable for input ports that can suggest a range to output ports. More...
struct	spa_io_clock
	Absolute time reporting. More...
struct	spa_io_video_size
struct	spa_io_latency
	Latency reporting. More...
struct	spa_io_sequence
	control stream, io area for SPA_IO_Control and SPA_IO_Notify More...
struct	spa_io_segment_bar
	bar and beat segment More...
struct	spa_io_segment_video
	video frame segment More...
struct	spa_io_segment
	A segment converts a running time to a segment (stream) position. More...
struct	spa_io_position
	The position information adds extra meaning to the raw clock times. More...
struct	spa_io_rate_match
	rate matching More...
struct	spa_io_async_buffers
	async buffers More...
struct	spa_node
struct	spa_node_info
	Node information structure. More...
struct	spa_port_info
	Port information structure. More...
struct	spa_result_node_error
	an error result More...
struct	spa_result_node_params
	the result of enum_params or port_enum_params. More...
struct	spa_node_events
	events from the spa_node. More...
struct	spa_node_callbacks
	Node callbacks. More...
struct	spa_node_methods
	Node methods. More...
struct	spa_result_node_params_data

Enumerations
enum	spa_node_command {   SPA_NODE_COMMAND_Suspend , SPA_NODE_COMMAND_Pause , SPA_NODE_COMMAND_Start , SPA_NODE_COMMAND_Enable ,   SPA_NODE_COMMAND_Disable , SPA_NODE_COMMAND_Flush , SPA_NODE_COMMAND_Drain , SPA_NODE_COMMAND_Marker ,   SPA_NODE_COMMAND_ParamBegin , SPA_NODE_COMMAND_ParamEnd , SPA_NODE_COMMAND_RequestProcess }
enum	spa_node_event { SPA_NODE_EVENT_Error , SPA_NODE_EVENT_Buffering , SPA_NODE_EVENT_RequestRefresh , SPA_NODE_EVENT_RequestProcess }
enum	spa_event_node { SPA_EVENT_NODE_START }
enum	spa_io_type {   SPA_IO_Invalid , SPA_IO_Buffers , SPA_IO_Range , SPA_IO_Clock ,   SPA_IO_Latency , SPA_IO_Control , SPA_IO_Notify , SPA_IO_Position ,   SPA_IO_RateMatch , SPA_IO_Memory , SPA_IO_AsyncBuffers }
	IO areas. More...
enum	spa_io_position_state { SPA_IO_POSITION_STATE_STOPPED , SPA_IO_POSITION_STATE_STARTING , SPA_IO_POSITION_STATE_RUNNING }

Macros
#define	SPA_NODE_COMMAND_ID(cmd)
#define	SPA_NODE_COMMAND_INIT(id)
#define	SPA_NODE_EVENT_ID(ev)
#define	SPA_NODE_EVENT_INIT(id)
#define	SPA_STATUS_OK   0
#define	SPA_STATUS_NEED_DATA   (1<<0)
#define	SPA_STATUS_HAVE_DATA   (1<<1)
#define	SPA_STATUS_STOPPED   (1<<2)
#define	SPA_STATUS_DRAINED   (1<<3)
#define	SPA_IO_BUFFERS_INIT   ((struct spa_io_buffers) { SPA_STATUS_OK, SPA_ID_INVALID, })
#define	SPA_IO_MEMORY_INIT   ((struct spa_io_memory) { SPA_STATUS_OK, 0, NULL, })
#define	SPA_IO_CLOCK_FLAG_FREEWHEEL   (1u<<0) /* graph is freewheeling */
#define	SPA_IO_CLOCK_FLAG_XRUN_RECOVER   (1u<<1) /* recovering from xrun */
#define	SPA_IO_VIDEO_SIZE_VALID   (1<<0)
#define	SPA_IO_SEGMENT_BAR_FLAG_VALID   (1<<0)
#define	SPA_IO_SEGMENT_VIDEO_FLAG_VALID   (1<<0)
#define	SPA_IO_SEGMENT_VIDEO_FLAG_DROP_FRAME   (1<<1)
#define	SPA_IO_SEGMENT_VIDEO_FLAG_PULL_DOWN   (1<<2)
#define	SPA_IO_SEGMENT_VIDEO_FLAG_INTERLACED   (1<<3)
#define	SPA_IO_SEGMENT_FLAG_LOOPING   (1<<0)
	after the duration, the segment repeats
#define	SPA_IO_SEGMENT_FLAG_NO_POSITION   (1<<1)
	position is invalid.
#define	SPA_IO_POSITION_MAX_SEGMENTS   8
	the maximum number of segments visible in the future
#define	SPA_IO_RATE_MATCH_FLAG_ACTIVE   (1 << 0)
#define	SPA_KEY_NODE_NAME   "node.name"
	node keys
#define	SPA_KEY_NODE_DESCRIPTION   "node.description"
	localized human readable node one-line description.
#define	SPA_KEY_NODE_LATENCY   "node.latency"
	the requested node latency
#define	SPA_KEY_NODE_MAX_LATENCY   "node.max-latency"
	maximum supported latency
#define	SPA_KEY_NODE_DRIVER   "node.driver"
	the node can be a driver
#define	SPA_KEY_NODE_ALWAYS_PROCESS   "node.always-process"
	call the process function even if not linked.
#define	SPA_KEY_NODE_PAUSE_ON_IDLE   "node.pause-on-idle"
	if the node should be paused immediately when idle.
#define	SPA_KEY_NODE_MONITOR   "node.monitor"
	the node has monitor ports
#define	SPA_KEY_PORT_NAME   "port.name"
	port keys
#define	SPA_KEY_PORT_ALIAS   "port.alias"
	a port alias
#define	SPA_KEY_PORT_MONITOR   "port.monitor"
	this port is a monitor port
#define	SPA_KEY_PORT_IGNORE_LATENCY   "port.ignore-latency"
	latency ignored by peers
#define	SPA_KEY_PORT_GROUP   "port.group"
	the port group this port belongs to
#define	SPA_TYPE_INTERFACE_Node   SPA_TYPE_INFO_INTERFACE_BASE "Node"
#define	SPA_VERSION_NODE   0
#define	SPA_NODE_CHANGE_MASK_FLAGS   (1u<<0)
#define	SPA_NODE_CHANGE_MASK_PROPS   (1u<<1)
#define	SPA_NODE_CHANGE_MASK_PARAMS   (1u<<2)
#define	SPA_NODE_FLAG_RT   (1u<<0)
	node can do real-time processing
#define	SPA_NODE_FLAG_IN_DYNAMIC_PORTS   (1u<<1)
	input ports can be added/removed
#define	SPA_NODE_FLAG_OUT_DYNAMIC_PORTS   (1u<<2)
	output ports can be added/removed
#define	SPA_NODE_FLAG_IN_PORT_CONFIG   (1u<<3)
	input ports can be reconfigured with PortConfig parameter
#define	SPA_NODE_FLAG_OUT_PORT_CONFIG   (1u<<4)
	output ports can be reconfigured with PortConfig parameter
#define	SPA_NODE_FLAG_NEED_CONFIGURE   (1u<<5)
	node needs configuration before it can be started.
#define	SPA_NODE_FLAG_ASYNC   (1u<<6)
	the process function might not immediately produce or consume data but might offload the work to a worker thread.
#define	SPA_NODE_INFO_INIT()
#define	SPA_PORT_CHANGE_MASK_FLAGS   (1u<<0)
#define	SPA_PORT_CHANGE_MASK_RATE   (1u<<1)
#define	SPA_PORT_CHANGE_MASK_PROPS   (1u<<2)
#define	SPA_PORT_CHANGE_MASK_PARAMS   (1u<<3)
#define	SPA_PORT_FLAG_REMOVABLE   (1u<<0)
	port can be removed
#define	SPA_PORT_FLAG_OPTIONAL   (1u<<1)
	processing on port is optional
#define	SPA_PORT_FLAG_CAN_ALLOC_BUFFERS   (1u<<2)
	the port can allocate buffer data
#define	SPA_PORT_FLAG_IN_PLACE   (1u<<3)
	the port can process data in-place and will need a writable input buffer
#define	SPA_PORT_FLAG_NO_REF   (1u<<4)
	the port does not keep a ref on the buffer.
#define	SPA_PORT_FLAG_LIVE   (1u<<5)
	output buffers from this port are timestamped against a live clock.
#define	SPA_PORT_FLAG_PHYSICAL   (1u<<6)
	connects to some device
#define	SPA_PORT_FLAG_TERMINAL   (1u<<7)
	data was not created from this port or will not be made available on another port
#define	SPA_PORT_FLAG_DYNAMIC_DATA   (1u<<8)
	data pointer on buffers can be changed.
#define	SPA_PORT_INFO_INIT()
#define	SPA_RESULT_TYPE_NODE_ERROR   1
#define	SPA_RESULT_TYPE_NODE_PARAMS   2
#define	SPA_NODE_EVENT_INFO   0
#define	SPA_NODE_EVENT_PORT_INFO   1
#define	SPA_NODE_EVENT_RESULT   2
#define	SPA_NODE_EVENT_EVENT   3
#define	SPA_NODE_EVENT_NUM   4
#define	SPA_VERSION_NODE_EVENTS   0
#define	SPA_NODE_CALLBACK_READY   0
#define	SPA_NODE_CALLBACK_REUSE_BUFFER   1
#define	SPA_NODE_CALLBACK_XRUN   2
#define	SPA_NODE_CALLBACK_NUM   3
#define	SPA_VERSION_NODE_CALLBACKS   0
#define	SPA_NODE_PARAM_FLAG_TEST_ONLY   (1 << 0)
	flags that can be passed to set_param and port_set_param functions
#define	SPA_NODE_PARAM_FLAG_FIXATE   (1 << 1)
	Fixate the non-optional unset fields.
#define	SPA_NODE_PARAM_FLAG_NEAREST   (1 << 2)
	Allow set fields to be rounded to the nearest allowed field value.
#define	SPA_NODE_BUFFERS_FLAG_ALLOC   (1 << 0)
	flags to pass to the use_buffers functions
#define	SPA_NODE_METHOD_ADD_LISTENER   0
#define	SPA_NODE_METHOD_SET_CALLBACKS   1
#define	SPA_NODE_METHOD_SYNC   2
#define	SPA_NODE_METHOD_ENUM_PARAMS   3
#define	SPA_NODE_METHOD_SET_PARAM   4
#define	SPA_NODE_METHOD_SET_IO   5
#define	SPA_NODE_METHOD_SEND_COMMAND   6
#define	SPA_NODE_METHOD_ADD_PORT   7
#define	SPA_NODE_METHOD_REMOVE_PORT   8
#define	SPA_NODE_METHOD_PORT_ENUM_PARAMS   9
#define	SPA_NODE_METHOD_PORT_SET_PARAM   10
#define	SPA_NODE_METHOD_PORT_USE_BUFFERS   11
#define	SPA_NODE_METHOD_PORT_SET_IO   12
#define	SPA_NODE_METHOD_PORT_REUSE_BUFFER   13
#define	SPA_NODE_METHOD_PROCESS   14
#define	SPA_NODE_METHOD_NUM   15
#define	SPA_VERSION_NODE_METHODS   0
#define	spa_node_method(o, method, version, ...)
#define	spa_node_method_fast(o, method, version, ...)
#define	spa_node_add_listener(n, ...)
	Adds an event listener on node.
#define	spa_node_set_callbacks(n, ...)
	Set callbacks to on node.
#define	spa_node_sync(n, ...)
	Perform a sync operation.
#define	spa_node_enum_params(n, ...)
	Enumerate the parameters of a node.
#define	spa_node_set_param(n, ...)
	Set the configurable parameter in node.
#define	spa_node_set_io(n, ...)
	Configure the given memory area with id on node.
#define	spa_node_send_command(n, ...)
	Send a command to a node.
#define	spa_node_add_port(n, ...)
	Make a new port with port_id.
#define	spa_node_remove_port(n, ...)
	Remove a port with port_id.
#define	spa_node_port_enum_params(n, ...)
	Enumerate all possible parameters of id on port_id of node that are compatible with filter.
#define	spa_node_port_set_param(n, ...)
	Set a parameter on port_id of node.
#define	spa_node_port_use_buffers(n, ...)
	Tell the port to use the given buffers.
#define	spa_node_port_set_io(n, ...)
	Configure the given memory area with id on port_id.
#define	spa_node_port_reuse_buffer(n, ...)
	Tell an output port to reuse a buffer.
#define	spa_node_port_reuse_buffer_fast(n, ...)
#define	spa_node_process(n)
	Process the node.
#define	spa_node_process_fast(n)
#define	SPA_TYPE_INFO_IO   SPA_TYPE_INFO_ENUM_BASE "IO"
#define	SPA_TYPE_INFO_IO_BASE   SPA_TYPE_INFO_IO ":"
#define	SPA_TYPE_INFO_NodeEvent   SPA_TYPE_INFO_EVENT_BASE "Node"
#define	SPA_TYPE_INFO_NODE_EVENT_BASE   SPA_TYPE_INFO_NodeEvent ":"
#define	SPA_TYPE_INFO_NodeCommand   SPA_TYPE_INFO_COMMAND_BASE "Node"
#define	SPA_TYPE_INFO_NODE_COMMAND_BASE   SPA_TYPE_INFO_NodeCommand ":"
#define	spa_node_emit(hooks, method, version, ...)
#define	spa_node_emit_info(hooks, ...)
#define	spa_node_emit_port_info(hooks, ...)
#define	spa_node_emit_result(hooks, ...)
#define	spa_node_emit_event(hooks, ...)
#define	spa_node_call(callbacks, method, version, ...)
#define	spa_node_call_ready(hook, ...)
#define	spa_node_call_reuse_buffer(hook, ...)
#define	spa_node_call_xrun(hook, ...)

Functions
static void	spa_result_func_node_params (void *data, int seq, int res 1, uint32_t type 1, const void *result)
static int	spa_node_enum_params_sync (struct spa_node *node, uint32_t id, uint32_t *index, const struct spa_pod *filter, struct spa_pod **param, struct spa_pod_builder *builder)
static int	spa_node_port_enum_params_sync (struct spa_node *node, enum spa_direction direction, uint32_t port_id, uint32_t id, uint32_t *index, const struct spa_pod *filter, struct spa_pod **param, struct spa_pod_builder *builder)

Variables
static const struct spa_type_info	spa_type_io []
static const struct spa_type_info	spa_type_node_event_id []
static const struct spa_type_info	spa_type_node_event []
static const struct spa_type_info	spa_type_node_command_id []
static const struct spa_type_info	spa_type_node_command []

Detailed Description

A spa_node is a component that can consume and produce buffers.

Enumeration Type Documentation

spa_node_command

enum spa_node_command

Enumerator
SPA_NODE_COMMAND_Suspend	suspend a node, this removes all configured formats and closes any devices
SPA_NODE_COMMAND_Pause	pause a node. this makes it stop emitting scheduling events
SPA_NODE_COMMAND_Start	start a node, this makes it start emitting scheduling events
SPA_NODE_COMMAND_Enable
SPA_NODE_COMMAND_Disable
SPA_NODE_COMMAND_Flush
SPA_NODE_COMMAND_Drain
SPA_NODE_COMMAND_Marker
SPA_NODE_COMMAND_ParamBegin	begin a set of parameter enumerations or configuration that require the device to remain opened, like query formats and then set a format
SPA_NODE_COMMAND_ParamEnd	end a transaction
SPA_NODE_COMMAND_RequestProcess	Sent to a driver when some other node emitted the RequestProcess event.

spa_node_event

enum spa_node_event

Enumerator
SPA_NODE_EVENT_Error
SPA_NODE_EVENT_Buffering
SPA_NODE_EVENT_RequestRefresh
SPA_NODE_EVENT_RequestProcess

spa_event_node

enum spa_event_node

Enumerator
SPA_EVENT_NODE_START

spa_io_type

enum spa_io_type

IO areas.

IO information for a port on a node. This is allocated by the host and configured on a node or all ports for which IO is requested.

The plugin will communicate with the host through the IO areas. Different IO area types

Enumerator
SPA_IO_Invalid
SPA_IO_Buffers	area to exchange buffers, struct spa_io_buffers
SPA_IO_Range	expected byte range, struct spa_io_range (currently not used in PipeWire)
SPA_IO_Clock	area to update clock information, struct spa_io_clock
SPA_IO_Latency	latency reporting, struct spa_io_latency (currently not used in PipeWire). See also spa_param_latency
SPA_IO_Control	area for control messages, struct spa_io_sequence
SPA_IO_Notify	area for notify messages, struct spa_io_sequence
SPA_IO_Position	position information in the graph, struct spa_io_position
SPA_IO_RateMatch	rate matching between nodes, struct spa_io_rate_match
SPA_IO_Memory	memory pointer, struct spa_io_memory (currently not used in PipeWire)
SPA_IO_AsyncBuffers	async area to exchange buffers, struct spa_io_async_buffers

spa_io_position_state

enum spa_io_position_state

Enumerator
SPA_IO_POSITION_STATE_STOPPED
SPA_IO_POSITION_STATE_STARTING
SPA_IO_POSITION_STATE_RUNNING

Macro Definition Documentation

SPA_NODE_COMMAND_ID

#define SPA_NODE_COMMAND_ID

(

cmd

)

Value:

SPA_COMMAND_ID(cmd, SPA_TYPE_COMMAND_Node)

Examples

video-play-pull.c.

SPA_NODE_COMMAND_INIT

#define SPA_NODE_COMMAND_INIT

(

id

)

Value:

SPA_COMMAND_INIT(SPA_TYPE_COMMAND_Node, id)

Examples

local-v4l2.c, spa/examples/adapter-control.c, spa/examples/example-control.c, spa/examples/local-libcamera.c, and spa/examples/local-v4l2.c.

SPA_NODE_EVENT_ID

#define SPA_NODE_EVENT_ID

(

ev

)

Value:

SPA_EVENT_ID(ev, SPA_TYPE_EVENT_Node)

SPA_NODE_EVENT_INIT

#define SPA_NODE_EVENT_INIT

(

id

)

Value:

SPA_EVENT_INIT(SPA_TYPE_EVENT_Node, id)

SPA_STATUS_OK

#define SPA_STATUS_OK   0

Examples

spa/examples/adapter-control.c.

SPA_STATUS_NEED_DATA

#define SPA_STATUS_NEED_DATA   (1<<0)

Examples

export-sink.c, local-v4l2.c, spa/examples/adapter-control.c, spa/examples/local-libcamera.c, and spa/examples/local-v4l2.c.

SPA_STATUS_HAVE_DATA

#define SPA_STATUS_HAVE_DATA   (1<<1)

Examples

export-sink.c, export-source.c, local-v4l2.c, spa/examples/adapter-control.c, spa/examples/local-libcamera.c, and spa/examples/local-v4l2.c.

SPA_STATUS_STOPPED

#define SPA_STATUS_STOPPED   (1<<2)

Examples

spa/examples/adapter-control.c.

SPA_STATUS_DRAINED

#define SPA_STATUS_DRAINED   (1<<3)

SPA_IO_BUFFERS_INIT

#define SPA_IO_BUFFERS_INIT   ((struct spa_io_buffers) { SPA_STATUS_OK, SPA_ID_INVALID, })

Examples

local-v4l2.c, spa/examples/adapter-control.c, spa/examples/example-control.c, spa/examples/local-libcamera.c, and spa/examples/local-v4l2.c.

SPA_IO_MEMORY_INIT

#define SPA_IO_MEMORY_INIT   ((struct spa_io_memory) { SPA_STATUS_OK, 0, NULL, })

SPA_IO_CLOCK_FLAG_FREEWHEEL

#define SPA_IO_CLOCK_FLAG_FREEWHEEL   (1u<<0) /* graph is freewheeling */

SPA_IO_CLOCK_FLAG_XRUN_RECOVER

#define SPA_IO_CLOCK_FLAG_XRUN_RECOVER   (1u<<1) /* recovering from xrun */

SPA_IO_VIDEO_SIZE_VALID

#define SPA_IO_VIDEO_SIZE_VALID   (1<<0)

SPA_IO_SEGMENT_BAR_FLAG_VALID

#define SPA_IO_SEGMENT_BAR_FLAG_VALID   (1<<0)

SPA_IO_SEGMENT_VIDEO_FLAG_VALID

#define SPA_IO_SEGMENT_VIDEO_FLAG_VALID   (1<<0)

SPA_IO_SEGMENT_VIDEO_FLAG_DROP_FRAME

#define SPA_IO_SEGMENT_VIDEO_FLAG_DROP_FRAME   (1<<1)

SPA_IO_SEGMENT_VIDEO_FLAG_PULL_DOWN

#define SPA_IO_SEGMENT_VIDEO_FLAG_PULL_DOWN   (1<<2)

SPA_IO_SEGMENT_VIDEO_FLAG_INTERLACED

#define SPA_IO_SEGMENT_VIDEO_FLAG_INTERLACED   (1<<3)

SPA_IO_SEGMENT_FLAG_LOOPING

#define SPA_IO_SEGMENT_FLAG_LOOPING   (1<<0)

after the duration, the segment repeats

SPA_IO_SEGMENT_FLAG_NO_POSITION

#define SPA_IO_SEGMENT_FLAG_NO_POSITION   (1<<1)

position is invalid.

The position can be invalid after a seek, for example, when the exact mapping of the extra segment info (bar, video, ...) to position has not been determined yet

SPA_IO_POSITION_MAX_SEGMENTS

#define SPA_IO_POSITION_MAX_SEGMENTS   8

the maximum number of segments visible in the future

SPA_IO_RATE_MATCH_FLAG_ACTIVE

#define SPA_IO_RATE_MATCH_FLAG_ACTIVE   (1 << 0)

SPA_KEY_NODE_NAME

#define SPA_KEY_NODE_NAME   "node.name"

node keys

a node name

SPA_KEY_NODE_DESCRIPTION

#define SPA_KEY_NODE_DESCRIPTION   "node.description"

localized human readable node one-line description.

Ex. "Foobar USB Headset"

SPA_KEY_NODE_LATENCY

#define SPA_KEY_NODE_LATENCY   "node.latency"

the requested node latency

SPA_KEY_NODE_MAX_LATENCY

#define SPA_KEY_NODE_MAX_LATENCY   "node.max-latency"

maximum supported latency

SPA_KEY_NODE_DRIVER

#define SPA_KEY_NODE_DRIVER   "node.driver"

the node can be a driver

SPA_KEY_NODE_ALWAYS_PROCESS

#define SPA_KEY_NODE_ALWAYS_PROCESS   "node.always-process"

call the process function even if not linked.

SPA_KEY_NODE_PAUSE_ON_IDLE

#define SPA_KEY_NODE_PAUSE_ON_IDLE   "node.pause-on-idle"

if the node should be paused immediately when idle.

SPA_KEY_NODE_MONITOR

#define SPA_KEY_NODE_MONITOR   "node.monitor"

the node has monitor ports

SPA_KEY_PORT_NAME

#define SPA_KEY_PORT_NAME   "port.name"

port keys

a port name

SPA_KEY_PORT_ALIAS

#define SPA_KEY_PORT_ALIAS   "port.alias"

a port alias

SPA_KEY_PORT_MONITOR

#define SPA_KEY_PORT_MONITOR   "port.monitor"

this port is a monitor port

SPA_KEY_PORT_IGNORE_LATENCY

#define SPA_KEY_PORT_IGNORE_LATENCY   "port.ignore-latency"

latency ignored by peers

SPA_KEY_PORT_GROUP

#define SPA_KEY_PORT_GROUP   "port.group"

the port group this port belongs to

SPA_TYPE_INTERFACE_Node

#define SPA_TYPE_INTERFACE_Node   SPA_TYPE_INFO_INTERFACE_BASE "Node"

Examples

bluez-session.c, export-sink.c, export-source.c, export-spa.c, local-v4l2.c, spa/examples/adapter-control.c, spa/examples/example-control.c, spa/examples/local-libcamera.c, and spa/examples/local-v4l2.c.

SPA_VERSION_NODE

#define SPA_VERSION_NODE   0

Examples

export-sink.c, and export-source.c.

SPA_NODE_CHANGE_MASK_FLAGS

#define SPA_NODE_CHANGE_MASK_FLAGS   (1u<<0)

SPA_NODE_CHANGE_MASK_PROPS

#define SPA_NODE_CHANGE_MASK_PROPS   (1u<<1)

SPA_NODE_CHANGE_MASK_PARAMS

#define SPA_NODE_CHANGE_MASK_PARAMS   (1u<<2)

SPA_NODE_FLAG_RT

#define SPA_NODE_FLAG_RT   (1u<<0)

node can do real-time processing

SPA_NODE_FLAG_IN_DYNAMIC_PORTS

#define SPA_NODE_FLAG_IN_DYNAMIC_PORTS   (1u<<1)

input ports can be added/removed

SPA_NODE_FLAG_OUT_DYNAMIC_PORTS

#define SPA_NODE_FLAG_OUT_DYNAMIC_PORTS   (1u<<2)

output ports can be added/removed

SPA_NODE_FLAG_IN_PORT_CONFIG

#define SPA_NODE_FLAG_IN_PORT_CONFIG   (1u<<3)

input ports can be reconfigured with PortConfig parameter

SPA_NODE_FLAG_OUT_PORT_CONFIG

#define SPA_NODE_FLAG_OUT_PORT_CONFIG   (1u<<4)

output ports can be reconfigured with PortConfig parameter

SPA_NODE_FLAG_NEED_CONFIGURE

#define SPA_NODE_FLAG_NEED_CONFIGURE   (1u<<5)

node needs configuration before it can be started.

SPA_NODE_FLAG_ASYNC

#define SPA_NODE_FLAG_ASYNC   (1u<<6)

the process function might not immediately produce or consume data but might offload the work to a worker thread.

SPA_NODE_INFO_INIT

#define SPA_NODE_INFO_INIT

(

)

Value:

((struct spa_node_info) { 0, })

SPA_PORT_CHANGE_MASK_FLAGS

#define SPA_PORT_CHANGE_MASK_FLAGS   (1u<<0)

Examples

export-sink.c, and export-source.c.

SPA_PORT_CHANGE_MASK_RATE

#define SPA_PORT_CHANGE_MASK_RATE   (1u<<1)

SPA_PORT_CHANGE_MASK_PROPS

#define SPA_PORT_CHANGE_MASK_PROPS   (1u<<2)

Examples

export-source.c.

SPA_PORT_CHANGE_MASK_PARAMS

#define SPA_PORT_CHANGE_MASK_PARAMS   (1u<<3)

Examples

export-sink.c, and export-source.c.

SPA_PORT_FLAG_REMOVABLE

#define SPA_PORT_FLAG_REMOVABLE   (1u<<0)

port can be removed

SPA_PORT_FLAG_OPTIONAL

#define SPA_PORT_FLAG_OPTIONAL   (1u<<1)

processing on port is optional

SPA_PORT_FLAG_CAN_ALLOC_BUFFERS

#define SPA_PORT_FLAG_CAN_ALLOC_BUFFERS   (1u<<2)

the port can allocate buffer data

SPA_PORT_FLAG_IN_PLACE

#define SPA_PORT_FLAG_IN_PLACE   (1u<<3)

the port can process data in-place and will need a writable input buffer

SPA_PORT_FLAG_NO_REF

#define SPA_PORT_FLAG_NO_REF   (1u<<4)

the port does not keep a ref on the buffer.

This means the node will always completely consume the input buffer and it will be recycled after process.

SPA_PORT_FLAG_LIVE

#define SPA_PORT_FLAG_LIVE   (1u<<5)

output buffers from this port are timestamped against a live clock.

SPA_PORT_FLAG_PHYSICAL

#define SPA_PORT_FLAG_PHYSICAL   (1u<<6)

connects to some device

SPA_PORT_FLAG_TERMINAL

#define SPA_PORT_FLAG_TERMINAL   (1u<<7)

data was not created from this port or will not be made available on another port

SPA_PORT_FLAG_DYNAMIC_DATA

#define SPA_PORT_FLAG_DYNAMIC_DATA   (1u<<8)

data pointer on buffers can be changed.

Only the buffer data marked as DYNAMIC can be changed.

SPA_PORT_INFO_INIT

#define SPA_PORT_INFO_INIT

(

)

Value:

((struct spa_port_info) { 0, })

Examples

export-sink.c, and export-source.c.

SPA_RESULT_TYPE_NODE_ERROR

#define SPA_RESULT_TYPE_NODE_ERROR   1

SPA_RESULT_TYPE_NODE_PARAMS

#define SPA_RESULT_TYPE_NODE_PARAMS   2

Examples

export-sink.c, and export-source.c.

SPA_NODE_EVENT_INFO

#define SPA_NODE_EVENT_INFO   0

SPA_NODE_EVENT_PORT_INFO

#define SPA_NODE_EVENT_PORT_INFO   1

SPA_NODE_EVENT_RESULT

#define SPA_NODE_EVENT_RESULT   2

SPA_NODE_EVENT_EVENT

#define SPA_NODE_EVENT_EVENT   3

SPA_NODE_EVENT_NUM

#define SPA_NODE_EVENT_NUM   4

SPA_VERSION_NODE_EVENTS

#define SPA_VERSION_NODE_EVENTS   0

SPA_NODE_CALLBACK_READY

#define SPA_NODE_CALLBACK_READY   0

SPA_NODE_CALLBACK_REUSE_BUFFER

#define SPA_NODE_CALLBACK_REUSE_BUFFER   1

SPA_NODE_CALLBACK_XRUN

#define SPA_NODE_CALLBACK_XRUN   2

SPA_NODE_CALLBACK_NUM

#define SPA_NODE_CALLBACK_NUM   3

SPA_VERSION_NODE_CALLBACKS

#define SPA_VERSION_NODE_CALLBACKS   0

Examples

local-v4l2.c, spa/examples/adapter-control.c, spa/examples/example-control.c, spa/examples/local-libcamera.c, and spa/examples/local-v4l2.c.

SPA_NODE_PARAM_FLAG_TEST_ONLY

#define SPA_NODE_PARAM_FLAG_TEST_ONLY   (1 << 0)

flags that can be passed to set_param and port_set_param functions

Just check if the param is accepted

SPA_NODE_PARAM_FLAG_FIXATE

#define SPA_NODE_PARAM_FLAG_FIXATE   (1 << 1)

Fixate the non-optional unset fields.

SPA_NODE_PARAM_FLAG_NEAREST

#define SPA_NODE_PARAM_FLAG_NEAREST   (1 << 2)

Allow set fields to be rounded to the nearest allowed field value.

SPA_NODE_BUFFERS_FLAG_ALLOC

#define SPA_NODE_BUFFERS_FLAG_ALLOC   (1 << 0)

flags to pass to the use_buffers functions

Allocate memory for the buffers. This flag is ignored when the port does not have the SPA_PORT_FLAG_CAN_ALLOC_BUFFERS set.

Examples

local-v4l2.c, spa/examples/local-libcamera.c, and spa/examples/local-v4l2.c.

SPA_NODE_METHOD_ADD_LISTENER

#define SPA_NODE_METHOD_ADD_LISTENER   0

SPA_NODE_METHOD_SET_CALLBACKS

#define SPA_NODE_METHOD_SET_CALLBACKS   1

SPA_NODE_METHOD_SYNC

#define SPA_NODE_METHOD_SYNC   2

SPA_NODE_METHOD_ENUM_PARAMS

#define SPA_NODE_METHOD_ENUM_PARAMS   3

SPA_NODE_METHOD_SET_PARAM

#define SPA_NODE_METHOD_SET_PARAM   4

SPA_NODE_METHOD_SET_IO

#define SPA_NODE_METHOD_SET_IO   5

SPA_NODE_METHOD_SEND_COMMAND

#define SPA_NODE_METHOD_SEND_COMMAND   6

SPA_NODE_METHOD_ADD_PORT

#define SPA_NODE_METHOD_ADD_PORT   7

SPA_NODE_METHOD_REMOVE_PORT

#define SPA_NODE_METHOD_REMOVE_PORT   8

SPA_NODE_METHOD_PORT_ENUM_PARAMS

#define SPA_NODE_METHOD_PORT_ENUM_PARAMS   9

SPA_NODE_METHOD_PORT_SET_PARAM

#define SPA_NODE_METHOD_PORT_SET_PARAM   10

SPA_NODE_METHOD_PORT_USE_BUFFERS

#define SPA_NODE_METHOD_PORT_USE_BUFFERS   11

SPA_NODE_METHOD_PORT_SET_IO

#define SPA_NODE_METHOD_PORT_SET_IO   12

SPA_NODE_METHOD_PORT_REUSE_BUFFER

#define SPA_NODE_METHOD_PORT_REUSE_BUFFER   13

SPA_NODE_METHOD_PROCESS

#define SPA_NODE_METHOD_PROCESS   14

SPA_NODE_METHOD_NUM

#define SPA_NODE_METHOD_NUM   15

SPA_VERSION_NODE_METHODS

#define SPA_VERSION_NODE_METHODS   0

Examples

export-sink.c, and export-source.c.

spa_node_method

#define spa_node_method	(		o,
			method,
			version,
			... )

spa_node_method_fast

#define spa_node_method_fast	(		o,
			method,
			version,
			... )

spa_node_add_listener

#define spa_node_add_listener	(		n,
			... )

Value:

spa_node_method(n, add_listener, 0, __VA_ARGS__)

Adds an event listener on node.

Setting the events will trigger the info event and a port_info event for each managed port on the new listener.

Parameters

node	a spa_node
listener	a listener
events	a struct spa_node_events
data	data passed as first argument in functions of events

Returns

0 on success < 0 errno on error

See also

spa_node_methods.add_listener

spa_node_set_callbacks

#define spa_node_set_callbacks	(		n,
			... )

Value:

spa_node_method(n, set_callbacks, 0, __VA_ARGS__)

Set callbacks to on node.

if callbacks is NULL, the current callbacks are removed.

This function must be called from the main thread.

All callbacks are called from the data thread.

Parameters

node	a spa_node
callbacks	callbacks to set

Returns

0 on success -EINVAL when node is NULL

See also

spa_node_methods.set_callbacks

Examples

local-v4l2.c, spa/examples/adapter-control.c, spa/examples/example-control.c, spa/examples/local-libcamera.c, and spa/examples/local-v4l2.c.

spa_node_sync

#define spa_node_sync	(		n,
			... )

Value:

spa_node_method(n, sync, 0, __VA_ARGS__)

Perform a sync operation.

This method will emit the result event with the given sequence number synchronously or with the returned async return value asynchronously.

Because all methods are serialized in the node, this can be used to wait for completion of all previous method calls.

Parameters

seq	a sequence number

Returns

0 on success -EINVAL when node is NULL an async result

See also

spa_node_methods.sync

spa_node_enum_params

#define spa_node_enum_params	(		n,
			... )

Value:

spa_node_method(n, enum_params, 0, __VA_ARGS__)

Enumerate the parameters of a node.

Parameters are identified with an id. Some parameters can have multiple values, see the documentation of the parameter id.

Parameters can be filtered by passing a non-NULL filter.

The function will emit the result event up to max times with the result value. The seq in the result will either be the seq number when executed synchronously or the async return value of this function when executed asynchronously.

This function must be called from the main thread.

Parameters

node	a Node
seq	a sequence number to pass to the result event when this method is executed synchronously.
id	the param id to enumerate
start	the index of enumeration, pass 0 for the first item
max	the maximum number of parameters to enumerate
filter	and optional filter to use

Returns

0 when no more items can be iterated. -EINVAL when invalid arguments are given -ENOENT the parameter id is unknown -ENOTSUP when there are no parameters implemented on node an async return value when the result event will be emitted later.

See also

spa_node_methods.enum_params

spa_node_set_param

#define spa_node_set_param	(		n,
			... )

Value:

spa_node_method(n, set_param, 0, __VA_ARGS__)

Set the configurable parameter in node.

Usually, param will be obtained from enum_params and then modified but it is also possible to set another spa_pod as long as its keys and types match a supported object.

Objects with property keys that are not known are ignored.

This function must be called from the main thread.

Parameters

node	a Node
id	the parameter id to configure
flags	additional flags
param	the parameter to configure

Returns

0 on success -EINVAL when node is NULL -ENOTSUP when there are no parameters implemented on node -ENOENT the parameter is unknown

See also

spa_node_methods.set_param

Examples

local-v4l2.c, spa/examples/adapter-control.c, spa/examples/example-control.c, spa/examples/local-libcamera.c, and spa/examples/local-v4l2.c.

spa_node_set_io

#define spa_node_set_io	(		n,
			... )

Value:

spa_node_method(n, set_io, 0, __VA_ARGS__)

Configure the given memory area with id on node.

This structure is allocated by the host and is used to exchange data and parameters with the node.

Setting an io of NULL will disable the node io.

This function must be called from the main thread.

Parameters

id	the id of the io area, the available ids can be enumerated with the node parameters.
data	a io area memory
size	the size of data

Returns

0 on success -EINVAL when invalid input is given -ENOENT when id is unknown -ENOSPC when size is too small

See also

spa_node_methods.set_io

Examples

spa/examples/adapter-control.c.

spa_node_send_command

#define spa_node_send_command	(		n,
			... )

Value:

spa_node_method(n, send_command, 0, __VA_ARGS__)

Send a command to a node.

Upon completion, a command might change the state of a node.

This function must be called from the main thread.

Parameters

node	a spa_node
command	a spa_command

Returns

0 on success -EINVAL when node or command is NULL -ENOTSUP when this node can't process commands -EINVAL command is an invalid command

See also

spa_node_methods.send_command

Examples

local-v4l2.c, spa/examples/adapter-control.c, spa/examples/example-control.c, spa/examples/local-libcamera.c, and spa/examples/local-v4l2.c.

spa_node_add_port

#define spa_node_add_port	(		n,
			... )

Value:

spa_node_method(n, add_port, 0, __VA_ARGS__)

Make a new port with port_id.

The caller should use the lowest unused port id for the given direction.

Port ids should be between 0 and max_ports as obtained from the info event.

This function must be called from the main thread.

Parameters

node	a spa_node
direction	a enum spa_direction
port_id	an unused port id
props	extra properties

Returns

0 on success -EINVAL when node is NULL

See also

spa_node_methods.add_port

spa_node_remove_port

#define spa_node_remove_port	(		n,
			... )

Value:

spa_node_method(n, remove_port, 0, __VA_ARGS__)

Remove a port with port_id.

Parameters

node	a spa_node
direction	a enum spa_direction
port_id	a port id

Returns

0 on success -EINVAL when node is NULL or when port_id is unknown or when the port can't be removed.

See also

spa_node_methods.remove_port

spa_node_port_enum_params

#define spa_node_port_enum_params	(		n,
			... )

Value:

spa_node_method(n, port_enum_params, 0, __VA_ARGS__)

Enumerate all possible parameters of id on port_id of node that are compatible with filter.

When SPA_ID_INVALID is given as the port_id, the node will reply with the params that would be returned for a new port in the given direction.

The result parameters can be queried and modified and ultimately be used to call port_set_param.

The function will emit the result event up to max times with the result value. The seq in the result event will either be the seq number when executed synchronously or the async return value of this function when executed asynchronously.

This function must be called from the main thread.

Parameters

node	a spa_node
seq	a sequence number to pass to the result event when this method is executed synchronously.
direction	an spa_direction
port_id	the port to query or SPA_ID_INVALID
id	the parameter id to query
start	the first index to query, 0 to get the first item
max	the maximum number of params to query
filter	a parameter filter or NULL for no filter

Returns

0 when no more items can be iterated. -EINVAL when invalid parameters are given -ENOENT when id is unknown an async return value when the result event will be emitted later.

See also

spa_node_methods.port_enum_params

spa_node_port_set_param

#define spa_node_port_set_param	(		n,
			... )

Value:

spa_node_method(n, port_set_param, 0, __VA_ARGS__)

Set a parameter on port_id of node.

When param is NULL, the parameter will be unset.

This function must be called from the main thread. The node muse be paused or the port SPA_IO_Buffers area is NULL when this function is called with a param that changes the processing state (like a format change).

Parameters

node	a struct Node
direction	a enum spa_direction
port_id	the port to configure
id	the parameter id to set
flags	optional flags
param	a struct POD with the parameter to set

Returns

0 on success 1 on success, the value of param might have been changed depending on flags and the final value can be found by doing port_enum_params. -EINVAL when node is NULL or invalid arguments are given -ESRCH when one of the mandatory param properties is not specified and SPA_NODE_PARAM_FLAG_FIXATE was not set in flags. -ESRCH when the type or size of a property is not correct. -ENOENT when the param id is not found

See also

spa_node_methods.port_set_param

Examples

local-v4l2.c, spa/examples/adapter-control.c, spa/examples/example-control.c, spa/examples/local-libcamera.c, and spa/examples/local-v4l2.c.

spa_node_port_use_buffers

#define spa_node_port_use_buffers	(		n,
			... )

Value:

spa_node_method(n, port_use_buffers, 0, __VA_ARGS__)

Tell the port to use the given buffers.

When flags contains SPA_NODE_BUFFERS_FLAG_ALLOC, the data in the buffers should point to an array of at least 1 data entry with the desired supported type that will be filled by this function.

The port should also have a spa_io_buffers io area configured to exchange the buffers with the port.

For an input port, all the buffers will remain dequeued. Once a buffer has been queued on a port in the spa_io_buffers, it should not be reused until the reuse_buffer callback is notified or when the buffer has been returned in the spa_io_buffers of the port.

For output ports, all buffers will be queued in the port. When process returns SPA_STATUS_HAVE_DATA, buffers are available in one or more of the spa_io_buffers areas.

When a buffer can be reused, port_reuse_buffer() should be called or the buffer_id should be placed in the spa_io_buffers area before calling process.

Passing NULL as buffers will remove the reference that the port has on the buffers.

When this function returns async, use the spa_node_sync operation to wait for completion.

This function must be called from the main thread. The node muse be paused or the port SPA_IO_Buffers area is NULL when this function is called.

Parameters

object	an object implementing the interface
direction	a port direction
port_id	a port id
flags	extra flags
buffers	an array of buffer pointers
n_buffers	number of elements in buffers

Returns

0 on success

See also

spa_node_methods.port_use_buffers

Examples

local-v4l2.c, spa/examples/adapter-control.c, spa/examples/example-control.c, spa/examples/local-libcamera.c, and spa/examples/local-v4l2.c.

spa_node_port_set_io

#define spa_node_port_set_io	(		n,
			... )

Value:

spa_node_method(n, port_set_io, 0, __VA_ARGS__)

Configure the given memory area with id on port_id.

This structure is allocated by the host and is used to exchange data and parameters with the port.

Setting an io of NULL will disable the port io.

This function must be called from the main thread.

This function can be called when the node is running and the node must be prepared to handle changes in io areas while running. This is normally done by synchronizing the port io updates with the data processing loop.

Parameters

direction	a spa_direction
port_id	a port id
id	the id of the io area, the available ids can be enumerated with the port parameters.
data	a io area memory
size	the size of data

Returns

0 on success -EINVAL when invalid input is given -ENOENT when id is unknown -ENOSPC when size is too small

See also

spa_node_methods.port_set_io

Examples

local-v4l2.c, spa/examples/adapter-control.c, spa/examples/example-control.c, spa/examples/local-libcamera.c, and spa/examples/local-v4l2.c.

spa_node_port_reuse_buffer

#define spa_node_port_reuse_buffer	(		n,
			... )

Value:

spa_node_method(n, port_reuse_buffer, 0, __VA_ARGS__)

Tell an output port to reuse a buffer.

This function must be called from the data thread.

Parameters

node	a spa_node
port_id	a port id
buffer_id	a buffer id to reuse

Returns

0 on success -EINVAL when node is NULL

See also

spa_node_methods.port_reuse_buffer

spa_node_port_reuse_buffer_fast

#define spa_node_port_reuse_buffer_fast	(		n,
			... )

Value:

spa_node_method_fast(n, port_reuse_buffer, 0, __VA_ARGS__)

spa_node_process

#define spa_node_process

(

n

)

Value:

spa_node_method(n, process, 0)

Process the node.

This function must be called from the data thread.

Output io areas with SPA_STATUS_NEED_DATA will recycle the buffers if any.

Input areas with SPA_STATUS_HAVE_DATA are consumed if possible and the status is set to SPA_STATUS_NEED_DATA or SPA_STATUS_OK.

When the node has new output buffers, the SPA_STATUS_HAVE_DATA bit will be set.

When the node can accept new input in the next cycle, the SPA_STATUS_NEED_DATA bit will be set.

Note that the node might return SPA_STATUS_NEED_DATA even when no input ports have this status. This means that the amount of data still available on the input ports is likely not going to be enough for the next cycle and the host might need to prefetch data for the next cycle.

See also

spa_node_methods.process

Examples

local-v4l2.c, spa/examples/local-libcamera.c, and spa/examples/local-v4l2.c.

spa_node_process_fast

#define spa_node_process_fast

(

n

)

Value:

spa_node_method_fast(n, process, 0)

SPA_TYPE_INFO_IO

#define SPA_TYPE_INFO_IO   SPA_TYPE_INFO_ENUM_BASE "IO"

SPA_TYPE_INFO_IO_BASE

#define SPA_TYPE_INFO_IO_BASE   SPA_TYPE_INFO_IO ":"

SPA_TYPE_INFO_NodeEvent

#define SPA_TYPE_INFO_NodeEvent   SPA_TYPE_INFO_EVENT_BASE "Node"

SPA_TYPE_INFO_NODE_EVENT_BASE

#define SPA_TYPE_INFO_NODE_EVENT_BASE   SPA_TYPE_INFO_NodeEvent ":"

SPA_TYPE_INFO_NodeCommand

#define SPA_TYPE_INFO_NodeCommand   SPA_TYPE_INFO_COMMAND_BASE "Node"

SPA_TYPE_INFO_NODE_COMMAND_BASE

#define SPA_TYPE_INFO_NODE_COMMAND_BASE   SPA_TYPE_INFO_NodeCommand ":"

spa_node_emit

#define spa_node_emit	(		hooks,
			method,
			version,
			... )

spa_node_emit_info

#define spa_node_emit_info	(		hooks,
			... )

Value:

spa_node_emit(hooks,info, 0, __VA_ARGS__)

spa_node_emit_port_info

#define spa_node_emit_port_info	(		hooks,
			... )

Value:

spa_node_emit(hooks,port_info, 0, __VA_ARGS__)

Examples

export-sink.c, and export-source.c.

spa_node_emit_result

#define spa_node_emit_result	(		hooks,
			... )

Value:

spa_node_emit(hooks,result, 0, __VA_ARGS__)

Examples

export-sink.c, and export-source.c.

spa_node_emit_event

#define spa_node_emit_event	(		hooks,
			... )

Value:

spa_node_emit(hooks,event, 0, __VA_ARGS__)

spa_node_call

#define spa_node_call	(		callbacks,
			method,
			version,
			... )

spa_node_call_ready

#define spa_node_call_ready	(		hook,
			... )

Value:

spa_node_call(hook, ready, 0, __VA_ARGS__)

spa_node_call_reuse_buffer

#define spa_node_call_reuse_buffer	(		hook,
			... )

Value:

spa_node_call(hook, reuse_buffer, 0, __VA_ARGS__)

spa_node_call_xrun

#define spa_node_call_xrun	(		hook,
			... )

Value:

spa_node_call(hook, xrun, 0, __VA_ARGS__)

Function Documentation

spa_result_func_node_params()

static void spa_result_func_node_params ( void * data, int seq, int res 1, uint32_t type 1, const void * result )

inlinestatic

spa_node_enum_params_sync()

static int spa_node_enum_params_sync ( struct spa_node * node, uint32_t id, uint32_t * index, const struct spa_pod * filter, struct spa_pod ** param, struct spa_pod_builder * builder )

inlinestatic

Examples

local-v4l2.c, spa/examples/local-libcamera.c, and spa/examples/local-v4l2.c.

spa_node_port_enum_params_sync()

static int spa_node_port_enum_params_sync ( struct spa_node * node, enum spa_direction direction, uint32_t port_id, uint32_t id, uint32_t * index, const struct spa_pod * filter, struct spa_pod ** param, struct spa_pod_builder * builder )

inlinestatic

Examples

spa/examples/adapter-control.c.

Variable Documentation

spa_type_io

const struct spa_type_info spa_type_io[]

static

spa_type_node_event_id

const struct spa_type_info spa_type_node_event_id[]

static

spa_type_node_event

const struct spa_type_info spa_type_node_event[]

static

spa_type_node_command_id

const struct spa_type_info spa_type_node_command_id[]

static

spa_type_node_command

const struct spa_type_info spa_type_node_command[]

static