PipeWire  0.3.36
Stream Object

PipeWire stream objects. More...

Data Structures

struct  pw_buffer
 
struct  pw_stream_control
 
struct  pw_time
 A time structure. More...
 
struct  pw_stream_events
 Events for a stream. More...
 

Enumerations

enum  pw_stream_state {
  PW_STREAM_STATE_ERROR = -1 , PW_STREAM_STATE_UNCONNECTED = 0 , PW_STREAM_STATE_CONNECTING = 1 , PW_STREAM_STATE_PAUSED = 2 ,
  PW_STREAM_STATE_STREAMING = 3
}
 The state of a stream. More...
 
enum  pw_stream_flags {
  PW_STREAM_FLAG_NONE = 0 , PW_STREAM_FLAG_AUTOCONNECT = (1 << 0) , PW_STREAM_FLAG_INACTIVE = (1 << 1) , PW_STREAM_FLAG_MAP_BUFFERS = (1 << 2) ,
  PW_STREAM_FLAG_DRIVER = (1 << 3) , PW_STREAM_FLAG_RT_PROCESS = (1 << 4) , PW_STREAM_FLAG_NO_CONVERT = (1 << 5) , PW_STREAM_FLAG_EXCLUSIVE = (1 << 6) ,
  PW_STREAM_FLAG_DONT_RECONNECT = (1 << 7) , PW_STREAM_FLAG_ALLOC_BUFFERS = (1 << 8)
}
 Extra flags that can be used in pw_stream_connect() More...
 

Functions

const char * pw_stream_state_as_string (enum pw_stream_state state)
 Convert a stream state to a readable string. More...
 
struct pw_stream * pw_stream_new (struct pw_core *core, const char *name, struct pw_properties *props)
 Create a new unconneced Stream Object. More...
 
struct pw_stream * pw_stream_new_simple (struct pw_loop *loop, const char *name, struct pw_properties *props, const struct pw_stream_events *events, void *data)
 
void pw_stream_destroy (struct pw_stream *stream)
 Destroy a stream. More...
 
void pw_stream_add_listener (struct pw_stream *stream, struct spa_hook *listener, const struct pw_stream_events *events, void *data)
 
enum pw_stream_state pw_stream_get_state (struct pw_stream *stream, const char **error)
 
const char * pw_stream_get_name (struct pw_stream *stream)
 
struct pw_core * pw_stream_get_core (struct pw_stream *stream)
 
const struct pw_propertiespw_stream_get_properties (struct pw_stream *stream)
 
int pw_stream_update_properties (struct pw_stream *stream, const struct spa_dict *dict)
 
int pw_stream_connect (struct pw_stream *stream, enum pw_direction direction, uint32_t target_id, enum pw_stream_flags flags, const struct spa_pod **params, uint32_t n_params)
 Connect a stream for input or output on port_path. More...
 
uint32_t pw_stream_get_node_id (struct pw_stream *stream)
 Get the node ID of the stream. More...
 
int pw_stream_disconnect (struct pw_stream *stream)
 Disconnect stream
More...
 
int pw_stream_set_error (struct pw_stream *stream, int res, const char *error,...) 1(3
 Set the stream in error state. More...
 
int int pw_stream_update_params (struct pw_stream *stream, const struct spa_pod **params, uint32_t n_params)
 Complete the negotiation process with result code res. More...
 
const struct pw_stream_controlpw_stream_get_control (struct pw_stream *stream, uint32_t id)
 Get control values. More...
 
int pw_stream_set_control (struct pw_stream *stream, uint32_t id, uint32_t n_values, float *values,...)
 Set control values. More...
 
int pw_stream_get_time (struct pw_stream *stream, struct pw_time *time)
 Query the time on the stream
More...
 
struct pw_bufferpw_stream_dequeue_buffer (struct pw_stream *stream)
 Get a buffer that can be filled for playback streams or consumed for capture streams. More...
 
int pw_stream_queue_buffer (struct pw_stream *stream, struct pw_buffer *buffer)
 Submit a buffer for playback or recycle a buffer for capture. More...
 
int pw_stream_set_active (struct pw_stream *stream, bool active)
 Activate or deactivate the stream. More...
 
int pw_stream_flush (struct pw_stream *stream, bool drain)
 Flush a stream. More...
 
bool pw_stream_is_driving (struct pw_stream *stream)
 Check if the stream is driving. More...
 
int pw_stream_trigger_process (struct pw_stream *stream)
 Trigger a push/pull on the stream. More...
 

Detailed Description

PipeWire stream objects.

The stream object provides a convenient way to send and receive data streams from/to PipeWire.

See also Media Streams and Core API

Enumeration Type Documentation

◆ pw_stream_flags

Extra flags that can be used in pw_stream_connect()

Enumerator
PW_STREAM_FLAG_NONE 

no flags

PW_STREAM_FLAG_AUTOCONNECT 

try to automatically connect this stream

PW_STREAM_FLAG_INACTIVE 

start the stream inactive, pw_stream_set_active() needs to be called explicitly

PW_STREAM_FLAG_MAP_BUFFERS 

mmap the buffers except DmaBuf

PW_STREAM_FLAG_DRIVER 

be a driver

PW_STREAM_FLAG_RT_PROCESS 

call process from the realtime thread.

You MUST use RT safe functions in the process callback.

PW_STREAM_FLAG_NO_CONVERT 

don't convert format

PW_STREAM_FLAG_EXCLUSIVE 

require exclusive access to the device

PW_STREAM_FLAG_DONT_RECONNECT 

don't try to reconnect this stream when the sink/source is removed

PW_STREAM_FLAG_ALLOC_BUFFERS 

the application will allocate buffer memory.

In the add_buffer event, the data of the buffer should be set

◆ pw_stream_state

The state of a stream.

Enumerator
PW_STREAM_STATE_ERROR 

the stream is in error

PW_STREAM_STATE_UNCONNECTED 

unconnected

PW_STREAM_STATE_CONNECTING 

connection is in progress

PW_STREAM_STATE_PAUSED 

paused

PW_STREAM_STATE_STREAMING 

streaming

Function Documentation

◆ pw_stream_add_listener()

void pw_stream_add_listener ( struct pw_stream *  stream,
struct spa_hook listener,
const struct pw_stream_events events,
void *  data 
)

◆ pw_stream_connect()

int pw_stream_connect ( struct pw_stream *  stream,
enum pw_direction  direction,
uint32_t  target_id,
enum pw_stream_flags  flags,
const struct spa_pod **  params,
uint32_t  n_params 
)

Connect a stream for input or output on port_path.

Returns
0 on success < 0 on error.

You should connect to the process event and use pw_stream_dequeue_buffer() to get the latest metadata and data.

Parameters
streama Stream Object
directionthe stream direction
target_idthe target object id to connect to or PW_ID_ANY to let the manager select a target.
flagsstream flags
paramsan array with params. The params should ideally contain supported formats.
n_paramsnumber of items in params

References NAME, props, PW_DIRECTION_INPUT, pw_log_debug, SPA_CONTAINER_OF, SPA_DIRECTION_INPUT, and SPA_DIRECTION_OUTPUT.

◆ pw_stream_dequeue_buffer()

struct pw_buffer* pw_stream_dequeue_buffer ( struct pw_stream *  stream)

Get a buffer that can be filled for playback streams or consumed for capture streams.

References SPA_CONTAINER_OF.

◆ pw_stream_destroy()

void pw_stream_destroy ( struct pw_stream *  stream)

◆ pw_stream_disconnect()

int pw_stream_disconnect ( struct pw_stream *  stream)

◆ pw_stream_flush()

int pw_stream_flush ( struct pw_stream *  stream,
bool  drain 
)

Flush a stream.

When drain is true, the drained callback will be called when all data is played or recorded

References impl::context, pw_loop_invoke, and SPA_CONTAINER_OF.

◆ pw_stream_get_control()

const struct pw_stream_control* pw_stream_get_control ( struct pw_stream *  stream,
uint32_t  id 
)

Get control values.

◆ pw_stream_get_core()

struct pw_core* pw_stream_get_core ( struct pw_stream *  stream)

◆ pw_stream_get_name()

const char* pw_stream_get_name ( struct pw_stream *  stream)

◆ pw_stream_get_node_id()

uint32_t pw_stream_get_node_id ( struct pw_stream *  stream)

Get the node ID of the stream.

Returns
node ID.

◆ pw_stream_get_properties()

const struct pw_properties* pw_stream_get_properties ( struct pw_stream *  stream)

◆ pw_stream_get_state()

enum pw_stream_state pw_stream_get_state ( struct pw_stream *  stream,
const char **  error 
)

◆ pw_stream_get_time()

int pw_stream_get_time ( struct pw_stream *  stream,
struct pw_time time 
)

◆ pw_stream_is_driving()

bool pw_stream_is_driving ( struct pw_stream *  stream)

Check if the stream is driving.

The stream needs to have the PW_STREAM_FLAG_DRIVER set. When the stream is driving, pw_stream_trigger_process() needs to be called when data is available (output) or needed (input). Since 0.3.34

References SPA_CONTAINER_OF.

◆ pw_stream_new()

struct pw_stream* pw_stream_new ( struct pw_core *  core,
const char *  name,
struct pw_properties props 
)

Create a new unconneced Stream Object.

Returns
a newly allocated Stream Object
Parameters
corea The PipeWire Core Global Object
namea stream media name
propsstream properties, ownership is taken

References impl::context, and stream::impl.

◆ pw_stream_new_simple()

struct pw_stream* pw_stream_new_simple ( struct pw_loop loop,
const char *  name,
struct pw_properties props,
const struct pw_stream_events events,
void *  data 
)
Parameters
loopa PipeWire Loop to use
namea stream media name
propsstream properties, ownership is taken
eventsstream events
datadata passed to events

References stream::impl, props, pw_context_new(), and pw_properties_new().

◆ pw_stream_queue_buffer()

int pw_stream_queue_buffer ( struct pw_stream *  stream,
struct pw_buffer buffer 
)

Submit a buffer for playback or recycle a buffer for capture.

References buffer::busy, spa_meta_busy::count, buffer::id, NAME, pw_log_trace, and SPA_CONTAINER_OF.

◆ pw_stream_set_active()

int pw_stream_set_active ( struct pw_stream *  stream,
bool  active 
)

Activate or deactivate the stream.

References stream::active, NAME, pw_impl_node_set_active(), pw_log_debug, and SPA_CONTAINER_OF.

◆ pw_stream_set_control()

int pw_stream_set_control ( struct pw_stream *  stream,
uint32_t  id,
uint32_t  n_values,
float *  values,
  ... 
)

◆ pw_stream_set_error()

int pw_stream_set_error ( struct pw_stream *  stream,
int  res,
const char *  error,
  ... 
)

Set the stream in error state.

Parameters
streama Stream Object
resa result code
erroran error message

◆ pw_stream_state_as_string()

const char* pw_stream_state_as_string ( enum pw_stream_state  state)

◆ pw_stream_trigger_process()

int pw_stream_trigger_process ( struct pw_stream *  stream)

Trigger a push/pull on the stream.

One iteration of the graph will scheduled and process() will be called. Since 0.3.34

References impl::context, NAME, pw_log_trace, pw_loop_invoke, SPA_CONTAINER_OF, and SPA_DIRECTION_OUTPUT.

◆ pw_stream_update_params()

int int pw_stream_update_params ( struct pw_stream *  stream,
const struct spa_pod **  params,
uint32_t  n_params 
)

Complete the negotiation process with result code res.

This function should be called after notification of the format.

When res indicates success, params contain the parameters for the allocation state.

Parameters
streama Stream Object
paramsan array of params. The params should ideally contain parameters for doing buffer allocation.
n_paramsnumber of elements in params

References NAME, pw_log_debug, and SPA_CONTAINER_OF.

◆ pw_stream_update_properties()

int pw_stream_update_properties ( struct pw_stream *  stream,
const struct spa_dict dict 
)