Context

The PipeWire context object manages all locally available resources. More...

Files
file	src/pipewire/context.h
	pipewire/context.h

Data Structures
struct	pw_context_events
	context events emitted by the context object added with pw_context_add_listener More...
struct	pw_export_type
	data for registering export functions More...
struct	pw_context
struct	pw_global
struct	pw_impl_client
struct	pw_impl_node

Macros
#define	PW_VERSION_CONTEXT_EVENTS   1

Functions
struct pw_context *	pw_context_new (struct pw_loop *main_loop, struct pw_properties *props, size_t user_data_size)
	Make a new context object for a given main_loop. More...
void	pw_context_destroy (struct pw_context *context)
	destroy a context object, all resources except the main_loop will be destroyed More...
void *	pw_context_get_user_data (struct pw_context *context)
	Get the context user data. More...
void	pw_context_add_listener (struct pw_context *context, struct spa_hook *listener, const struct pw_context_events *events, void *data)
	Add a new event listener to a context. More...
const struct pw_properties *	pw_context_get_properties (struct pw_context *context)
	Get the context properties. More...
int	pw_context_update_properties (struct pw_context *context, const struct spa_dict *dict)
	Update the context properties. More...
const char *	pw_context_get_conf_section (struct pw_context *context, const char *section)
	Get a config section for this context. More...
int	pw_context_parse_conf_section (struct pw_context *context, struct pw_properties *conf, const char *section)
	Parse a standard config section for this context. More...
int	pw_context_conf_update_props (struct pw_context *context, const char *section, struct pw_properties *props)
	update properties from a section into props. More...
int	pw_context_conf_section_for_each (struct pw_context *context, const char *section, int(*callback)(void *data, const char *location, const char *section, const char *str, size_t len), void *data)
	emit callback for all config sections. More...
int	pw_context_conf_section_match_rules (struct pw_context *context, const char *section, const struct spa_dict *props, int(*callback)(void *data, const char *location, const char *action, const char *str, size_t len), void *data)
	emit callback for all matched properties. More...
const struct spa_support *	pw_context_get_support (struct pw_context *context, uint32_t *n_support)
	Get the context support objects. More...
struct pw_loop *	pw_context_get_main_loop (struct pw_context *context)
	get the context main loop More...
struct pw_data_loop *	pw_context_get_data_loop (struct pw_context *context)
	get the context data loop. More...
struct pw_work_queue *	pw_context_get_work_queue (struct pw_context *context)
	Get the work queue from the context: Since 0.3.26. More...
struct pw_mempool *	pw_context_get_mempool (struct pw_context *context)
	Get the memmory pool from the context: Since 0.3.74. More...
int	pw_context_for_each_global (struct pw_context *context, int(*callback)(void *data, struct pw_global *global), void *data)
	Iterate the globals of the context. More...
struct pw_global *	pw_context_find_global (struct pw_context *context, uint32_t id)
	Find a context global by id. More...
int	pw_context_add_spa_lib (struct pw_context *context, const char *factory_regex, const char *lib)
	add a spa library for the given factory_name regex More...
const char *	pw_context_find_spa_lib (struct pw_context *context, const char *factory_name)
	find the library name for a spa factory More...
struct spa_handle *	pw_context_load_spa_handle (struct pw_context *context, const char *factory_name, const struct spa_dict *info)
int	pw_context_register_export_type (struct pw_context *context, struct pw_export_type *type)
	register a type that can be exported on a context_proxy. More...
const struct pw_export_type *	pw_context_find_export_type (struct pw_context *context, const char *type)
	find information about registered export type More...
int	pw_context_set_object (struct pw_context *context, const char *type, void *value)
	add an object to the context More...
void *	pw_context_get_object (struct pw_context *context, const char *type)
	get an object from the context More...

Detailed Description

The PipeWire context object manages all locally available resources.

It is used by both clients and servers.

The context is used to:

• Load modules and extend the functionality. This includes extending the protocol with new object types or creating any of the available objects.
• Create implementations of various objects like nodes, devices, factories, modules, etc.. This will usually also create pw_global objects that can then be shared with clients.
• Connect to another PipeWire instance (the main daemon, for example) and interact with it (See page_core_api).
• Export a local implementation of an object to another instance.

Macro Definition Documentation

PW_VERSION_CONTEXT_EVENTS

#define PW_VERSION_CONTEXT_EVENTS   1

Function Documentation

pw_context_new()

struct pw_context * pw_context_new	(	struct pw_loop *	main_loop,
		struct pw_properties *	properties,
		size_t	user_data_size
	)

Make a new context object for a given main_loop.

Ownership of the properties is taken

Make a new context object for a given main_loop.

Parameters

main_loop	the main loop to use
properties	extra properties for the context, ownership it taken

Returns

a newly allocated context object

Parameters

main_loop	a main loop to run in
properties	extra properties
user_data_size	extra user data size

Examples

bluez-session.c, export-sink.c, export-source.c, export-spa-device.c, export-spa.c, internal.c, local-v4l2.c, tutorial2.c, tutorial3.c, tutorial6.c, and video-src.c.

pw_context_destroy()

void pw_context_destroy

(

struct pw_context *

context

)

destroy a context object, all resources except the main_loop will be destroyed

destroy a context object, all resources except the main_loop will be destroyed

Parameters

context

a context to destroy

Examples

bluez-session.c, export-sink.c, export-source.c, export-spa-device.c, export-spa.c, internal.c, local-v4l2.c, tutorial2.c, tutorial3.c, tutorial6.c, and video-src.c.

pw_context_get_user_data()

void * pw_context_get_user_data

(

struct pw_context *

context

)

Get the context user data.

pw_context_add_listener()

void pw_context_add_listener	(	struct pw_context *	context,
		struct spa_hook *	listener,
		const struct pw_context_events *	events,
		void *	data
	)

Add a new event listener to a context.

pw_context_get_properties()

const struct pw_properties * pw_context_get_properties

(

struct pw_context *

context

)

Get the context properties.

pw_context_update_properties()

int pw_context_update_properties	(	struct pw_context *	context,
		const struct spa_dict *	dict
	)

Update the context properties.

Update the context properties.

Parameters

context	a context
dict	properties to update

Update the context object with the given properties

pw_context_get_conf_section()

const char * pw_context_get_conf_section	(	struct pw_context *	context,
		const char *	section
	)

Get a config section for this context.

Since 0.3.22, deprecated, use pw_context_conf_section_for_each().

pw_context_parse_conf_section()

int pw_context_parse_conf_section	(	struct pw_context *	context,
		struct pw_properties *	conf,
		const char *	section
	)

Parse a standard config section for this context.

Since 0.3.22

pw_context_conf_update_props()

int pw_context_conf_update_props	(	struct pw_context *	context,
		const char *	section,
		struct pw_properties *	props
	)

update properties from a section into props.

Since 0.3.45

pw_context_conf_section_for_each()

int pw_context_conf_section_for_each	(	struct pw_context *	context,
		const char *	section,
		int(*)(void *data, const char *location, const char *section, const char *str, size_t len)	callback,
		void *	data
	)

emit callback for all config sections.

Since 0.3.45

pw_context_conf_section_match_rules()

int pw_context_conf_section_match_rules	(	struct pw_context *	context,
		const char *	section,
		const struct spa_dict *	props,
		int(*)(void *data, const char *location, const char *action, const char *str, size_t len)	callback,
		void *	data
	)

emit callback for all matched properties.

Since 0.3.46

pw_context_get_support()

const struct spa_support * pw_context_get_support	(	struct pw_context *	context,
		uint32_t *	n_support
	)

Get the context support objects.

pw_context_get_main_loop()

struct pw_loop * pw_context_get_main_loop

(

struct pw_context *

context

)

get the context main loop

pw_context_get_data_loop()

struct pw_data_loop * pw_context_get_data_loop

(

struct pw_context *

context

)

get the context data loop.

Since 0.3.56

pw_context_get_work_queue()

struct pw_work_queue * pw_context_get_work_queue

(

struct pw_context *

context

)

Get the work queue from the context: Since 0.3.26.

pw_context_get_mempool()

struct pw_mempool * pw_context_get_mempool

(

struct pw_context *

context

)

Get the memmory pool from the context: Since 0.3.74.

pw_context_for_each_global()

int pw_context_for_each_global	(	struct pw_context *	context,
		int(*)(void *data, struct pw_global *global)	callback,
		void *	data
	)

Iterate the globals of the context.

The callback should return 0 to fetch the next item, any other value stops the iteration and returns the value. When all callbacks return 0, this function returns 0 when all globals are iterated.

pw_context_find_global()

struct pw_global * pw_context_find_global	(	struct pw_context *	context,
		uint32_t	id
	)

Find a context global by id.

Parameters

context	the context
id	the global id

pw_context_add_spa_lib()

int pw_context_add_spa_lib	(	struct pw_context *	context,
		const char *	factory_regex,
		const char *	lib
	)

add a spa library for the given factory_name regex

pw_context_find_spa_lib()

const char * pw_context_find_spa_lib	(	struct pw_context *	context,
		const char *	factory_name
	)

find the library name for a spa factory

pw_context_load_spa_handle()

struct spa_handle * pw_context_load_spa_handle	(	struct pw_context *	context,
		const char *	factory_name,
		const struct spa_dict *	info
	)

Examples

bluez-session.c, and export-spa.c.

pw_context_register_export_type()

int pw_context_register_export_type	(	struct pw_context *	context,
		struct pw_export_type *	type
	)

register a type that can be exported on a context_proxy.

This is usually used by extension modules

pw_context_find_export_type()

const struct pw_export_type * pw_context_find_export_type	(	struct pw_context *	context,
		const char *	type
	)

find information about registered export type

pw_context_set_object()

int pw_context_set_object	(	struct pw_context *	context,
		const char *	type,
		void *	value
	)

add an object to the context

pw_context_get_object()

void * pw_context_get_object	(	struct pw_context *	context,
		const char *	type
	)

get an object from the context