PipeWire: Node

PipeWire 1.2.2

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Node
SPA

## 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) SPA_COMMAND_ID(cmd, SPA_TYPE_COMMAND_Node)
#define | SPA_NODE_COMMAND_INIT(id) SPA_COMMAND_INIT(SPA_TYPE_COMMAND_Node, id)
#define | SPA_NODE_EVENT_ID(ev) SPA_EVENT_ID(ev, SPA_TYPE_EVENT_Node)
#define | SPA_NODE_EVENT_INIT(id) SPA_EVENT_INIT(SPA_TYPE_EVENT_Node, 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() ((struct spa_node_info) { 0, })
#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() ((struct spa_port_info) { 0, })
#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, ...) spa_node_method(n, add_listener, 0, __VA_ARGS__)
| Adds an event listener on node.
#define | spa_node_set_callbacks(n, ...) spa_node_method(n, set_callbacks, 0, __VA_ARGS__)
| Set callbacks to on node.
#define | spa_node_sync(n, ...) spa_node_method(n, sync, 0, __VA_ARGS__)
| Perform a sync operation.
#define | spa_node_enum_params(n, ...) spa_node_method(n, enum_params, 0, __VA_ARGS__)
| Enumerate the parameters of a node.
#define | spa_node_set_param(n, ...) spa_node_method(n, set_param, 0, __VA_ARGS__)
| Set the configurable parameter in node.
#define | spa_node_set_io(n, ...) spa_node_method(n, set_io, 0, __VA_ARGS__)
| Configure the given memory area with id on node.
#define | spa_node_send_command(n, ...) spa_node_method(n, send_command, 0, __VA_ARGS__)
| Send a command to a node.
#define | spa_node_add_port(n, ...) spa_node_method(n, add_port, 0, __VA_ARGS__)
| Make a new port with port_id.
#define | spa_node_remove_port(n, ...) spa_node_method(n, remove_port, 0, __VA_ARGS__)
| Remove a port with port_id.
#define | spa_node_port_enum_params(n, ...) 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.
#define | spa_node_port_set_param(n, ...) spa_node_method(n, port_set_param, 0, __VA_ARGS__)
| Set a parameter on port_id of node.
#define | spa_node_port_use_buffers(n, ...) spa_node_method(n, port_use_buffers, 0, __VA_ARGS__)
| Tell the port to use the given buffers.
#define | spa_node_port_set_io(n, ...) spa_node_method(n, port_set_io, 0, __VA_ARGS__)
| Configure the given memory area with id on port_id.
#define | spa_node_port_reuse_buffer(n, ...) spa_node_method(n, port_reuse_buffer, 0, __VA_ARGS__)
| Tell an output port to reuse a buffer.
#define | spa_node_port_reuse_buffer_fast(n, ...) spa_node_method_fast(n, port_reuse_buffer, 0, __VA_ARGS__)
#define | spa_node_process(n) spa_node_method(n, process, 0)
| Process the node.
#define | spa_node_process_fast(n) spa_node_method_fast(n, process, 0)
#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, ...) spa_node_emit(hooks,info, 0, __VA_ARGS__)
#define | spa_node_emit_port_info(hooks, ...) spa_node_emit(hooks,port_info, 0, __VA_ARGS__)
#define | spa_node_emit_result(hooks, ...) spa_node_emit(hooks,result, 0, __VA_ARGS__)
#define | spa_node_emit_event(hooks, ...) spa_node_emit(hooks,event, 0, __VA_ARGS__)
#define | spa_node_call(callbacks, method, version, ...)
#define | spa_node_call_ready(hook, ...) spa_node_call(hook, ready, 0, __VA_ARGS__)
#define | spa_node_call_reuse_buffer(hook, ...) spa_node_call(hook, reuse_buffer, 0, __VA_ARGS__)
#define | spa_node_call_xrun(hook, ...) spa_node_call(hook, xrun, 0, __VA_ARGS__)

## 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 | ) | SPA_COMMAND_ID(cmd, SPA_TYPE_COMMAND_Node)

Examples
  video-play-pull.c.

## ◆ SPA_NODE_COMMAND_INIT

#define SPA_NODE_COMMAND_INIT | ( |  | id | ) | 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 | ) | SPA_EVENT_ID(ev, SPA_TYPE_EVENT_Node)

## ◆ SPA_NODE_EVENT_INIT

#define SPA_NODE_EVENT_INIT | ( |  | id | ) | 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 | ( |  | ) | ((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 | ( |  | ) | ((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,
|  |  | ... ) 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,
|  |  | ... ) 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,
|  |  | ... ) 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,
|  |  | ... ) 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,
|  |  | ... ) 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,
|  |  | ... ) 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,
|  |  | ... ) 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,
|  |  | ... ) 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,
|  |  | ... ) 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,
|  |  | ... ) 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,
|  |  | ... ) 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,
|  |  | ... ) 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,
|  |  | ... ) 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,
|  |  | ... ) 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,
|  |  | ... ) spa_node_method_fast(n, port_reuse_buffer, 0, __VA_ARGS__)

## ◆ spa_node_process

#define spa_node_process | ( |  | n | ) | 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 | ) | 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,
|  |  | ... ) spa_node_emit(hooks,info, 0, __VA_ARGS__)

## ◆ spa_node_emit_port_info

#define spa_node_emit_port_info | ( |  | hooks,
|  |  | ... ) 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,
|  |  | ... ) 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,
|  |  | ... ) 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,
|  |  | ... ) spa_node_call(hook, ready, 0, __VA_ARGS__)

## ◆ spa_node_call_reuse_buffer

#define spa_node_call_reuse_buffer | ( |  | hook,
|  |  | ... ) spa_node_call(hook, reuse_buffer, 0, __VA_ARGS__)

## ◆ spa_node_call_xrun

#define spa_node_call_xrun | ( |  | hook,
|  |  | ... ) 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