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/* PipeWire */
/* SPDX-FileCopyrightText: Copyright © 2018 Wim Taymans */
/* SPDX-License-Identifier: MIT */
#ifndef PIPEWIRE_STREAM_H
#define PIPEWIRE_STREAM_H
#ifdef __cplusplus
extern "C" {
#endif
/** \page page_streams Streams
*
* \see \ref pw_stream
*
* \section sec_overview Overview
*
* \ref pw_stream "Streams" are used to exchange data with the
* PipeWire server. A stream is a wrapper around a proxy for a pw_client_node
* with an adapter. This means the stream will automatically do conversion
* to the type required by the server.
*
* Streams can be used to:
*
* \li Consume a stream from PipeWire. This is a PW_DIRECTION_INPUT stream.
* \li Produce a stream to PipeWire. This is a PW_DIRECTION_OUTPUT stream
*
* You can connect the stream port to a specific server port or let PipeWire
* choose a port for you.
*
* For more complicated nodes such as filters or ports with multiple
* inputs and/or outputs you will need to use the pw_filter or make
* a pw_node yourself and export it with \ref pw_core_export.
*
* Streams can also be used to:
*
* \li Implement a Sink in PipeWire. This is a PW_DIRECTION_INPUT stream.
* \li Implement a Source in PipeWire. This is a PW_DIRECTION_OUTPUT stream
*
* In this case, the PW_KEY_MEDIA_CLASS property needs to be set to
* "Audio/Sink" or "Audio/Source" respectively.
*
* \section sec_create Create
*
* Make a new stream with \ref pw_stream_new(). You will need to specify
* a name for the stream and extra properties. The basic set of properties
* each stream must provide is filled in automatically.
*
* Once the stream is created, the state_changed event should be used to
* track the state of the stream.
*
* \section sec_connect Connect
*
* The stream is initially unconnected. To connect the stream, use
* \ref pw_stream_connect(). Pass the desired direction as an argument.
*
* The direction is:
* \li PW_DIRECTION_INPUT for a stream that *consumes* data. This can be a
* stream that captures from a Source or a when the stream is used to
* implement a Sink.
*
* \li PW_DIRECTION_OUTPUT for a stream that *produces* data. This can be a
* stream that plays to a Sink or when the stream is used to implement
* a Source.
*
* \subsection ssec_stream_target Stream target
*
* To make the newly connected stream automatically connect to an existing
* PipeWire node, use the \ref PW_STREAM_FLAG_AUTOCONNECT and set the
* PW_KEY_OBJECT_SERIAL or the PW_KEY_NODE_NAME value of the target node
* in the PW_KEY_TARGET_OBJECT property before connecting.
*
* \subsection ssec_stream_formats Stream formats
*
* An array of possible formats that this stream can consume or provide
* must be specified.
*
* \section sec_format Format negotiation
*
* After connecting the stream, the server will want to configure some
* parameters on the stream. You will be notified of these changes
* with the param_changed event.
*
* When a format param change is emitted, the client should now prepare
* itself to deal with the format and complete the negotiation procedure
* with a call to \ref pw_stream_update_params().
*
* As arguments to \ref pw_stream_update_params() an array of spa_param
* structures must be given. They contain parameters such as buffer size,
* number of buffers, required metadata and other parameters for the
* media buffers.
*
* \section sec_buffers Buffer negotiation
*
* After completing the format negotiation, PipeWire will allocate and
* notify the stream of the buffers that will be used to exchange data
* between client and server.
*
* With the add_buffer event, a stream will be notified of a new buffer
* that can be used for data transport. You can attach user_data to these
* buffers. The buffers can only be used with the stream that emitted
* the add_buffer event.
*
* After the buffers are negotiated, the stream will transition to the
* \ref PW_STREAM_STATE_PAUSED state.
*
* \section sec_streaming Streaming
*
* From the \ref PW_STREAM_STATE_PAUSED state, the stream can be set to
* the \ref PW_STREAM_STATE_STREAMING state by the PipeWire server when
* data transport is started.
*
* Depending on how the stream was connected it will need to Produce or
* Consume data for/from PipeWire as explained in the following
* subsections.
*
* \subsection ssec_consume Consume data
*
* The process event is emitted for each new buffer that can be
* consumed.
*
* \ref pw_stream_dequeue_buffer() should be used to get the data and
* metadata of the buffer.
*
* The buffer is owned by the stream and stays alive until the
* remove_buffer callback has returned or the stream is destroyed.
*
* When the buffer has been processed, call \ref pw_stream_queue_buffer()
* to let PipeWire reuse the buffer.
*
* \subsection ssec_produce Produce data
*
* \ref pw_stream_dequeue_buffer() gives an empty buffer that can be filled.
*
* The buffer is owned by the stream and stays alive until the
* remove_buffer event is emitted or the stream is destroyed.
*
* Filled buffers should be queued with \ref pw_stream_queue_buffer().
*
* The process event is emitted when PipeWire has emptied a buffer that
* can now be refilled.
*
* \section sec_stream_disconnect Disconnect
*
* Use \ref pw_stream_disconnect() to disconnect a stream after use.
*
* \section sec_stream_configuration Configuration
*
* \subsection ssec_config_properties Stream Properties
*
* \subsection ssec_config_rules Stream Rules
*
* \section sec_stream_environment Environment Variables
*
* The environment variable PIPEWIRE_AUTOCONNECT can be used to override the
* flag and force apps to autoconnect or not.
*
*/
/** \defgroup pw_stream Stream
*
* \brief PipeWire stream objects
*
* The stream object provides a convenient way to send and
* receive data streams from/to PipeWire.
*
* \see \ref page_streams, \ref api_pw_core
*/
/**
* \addtogroup pw_stream
* \{
*/
struct pw_stream;
#include <spa/buffer/buffer.h>
#include <spa/param/param.h>
#include <spa/pod/command.h>
/** \enum pw_stream_state The state of a stream */
enum pw_stream_state {
PW_STREAM_STATE_ERROR = -1, /**< the stream is in error */
PW_STREAM_STATE_UNCONNECTED = 0, /**< unconnected */
PW_STREAM_STATE_CONNECTING = 1, /**< connection is in progress */
PW_STREAM_STATE_PAUSED = 2, /**< paused */
PW_STREAM_STATE_STREAMING = 3 /**< streaming */
};
/** a buffer structure obtained from pw_stream_dequeue_buffer(). The size of this
* structure can grow as more field are added in the future */
struct pw_buffer {
struct spa_buffer *buffer; /**< the spa buffer */
void *user_data; /**< user data attached to the buffer */
uint64_t size; /**< This field is set by the user and the sum of
* all queued buffer is returned in the time info.
* For audio, it is advised to use the number of
* samples in the buffer for this field. */
uint64_t requested; /**< For playback streams, this field contains the
* suggested amount of data to provide. For audio
* streams this will be the amount of samples
* required by the resampler. This field is 0
* when no suggestion is provided. Since 0.3.49 */
};
struct pw_stream_control {
const char *name; /**< name of the control */
uint32_t flags; /**< extra flags (unused) */
float def; /**< default value */
float min; /**< min value */
float max; /**< max value */
float *values; /**< array of values */
uint32_t n_values; /**< number of values in array */
uint32_t max_values; /**< max values that can be set on this control */
};
/** A time structure.
*
* Use pw_stream_get_time_n() to get an updated time snapshot of the stream.
* The time snapshot can give information about the time in the driver of the
* graph, the delay to the edge of the graph and the internal queuing in the
* stream.
*
* pw_time.ticks gives a monotonic increasing counter of the time in the graph
* driver. I can be used to generate a timetime to schedule samples as well
* as detect discontinuities in the timeline caused by xruns.
*
* pw_time.delay is expressed as pw_time.rate, the time domain of the graph. This
* value, and pw_time.ticks, were captured at pw_time.now and can be extrapolated
* to the current time like this:
*
*\code{.c}
* struct timespec ts;
* clock_gettime(CLOCK_MONOTONIC, &ts);
* int64_t diff = SPA_TIMESPEC_TO_NSEC(&ts) - pw_time.now;
* int64_t elapsed = (pw_time.rate.denom * diff) / (pw_time.rate.num * SPA_NSEC_PER_SEC);
*\endcode
*
* pw_time.delay contains the total delay that a signal will travel through the
* graph. This includes the delay caused by filters in the graph as well as delays
* caused by the hardware. The delay is usually quite stable and should only change when
* the topology, quantum or samplerate of the graph changes.
*
* pw_time.queued and pw_time.buffered is expressed in the time domain of the stream,
* or the format that is used for the buffers of this stream.
*
* pw_time.queued is the sum of all the pw_buffer.size fields of the buffers that are
* currently queued in the stream but not yet processed. The application can choose
* the units of this value, for example, time, samples or bytes (below expressed
* as app.rate).
*
* pw_time.buffered is format dependent, for audio/raw it contains the number of samples
* that are buffered inside the resampler/converter.
*
* The total delay of data in a stream is the sum of the queued and buffered data
* (not yet processed data) and the delay to the edge of the graph, usually a
* playback or capture device.
*
* For an audio playback stream, if you were to queue a buffer, the total delay
* in milliseconds for the first sample in the newly queued buffer to be played
* by the hardware can be calculated as:
*
*\code{.unparsed}
* (pw_time.buffered * 1000 / stream.samplerate) +
* (pw_time.queued * 1000 / app.rate) +
* ((pw_time.delay - elapsed) * 1000 * pw_time.rate.num / pw_time.rate.denom)
*\endcode
*
* The current extrapolated time (in ms) in the source or sink can be calculated as:
*
*\code{.unparsed}
* (pw_time.ticks + elapsed) * 1000 * pw_time.rate.num / pw_time.rate.denom
*\endcode
*
* Below is an overview of the different timing values:
*
*\code{.unparsed}
* stream time domain graph time domain
* /-----------------------\/-----------------------------\
*
* queue +-+ +-+ +-----------+ +--------+
* ----> | | | |->| converter | -> graph -> | kernel | -> speaker
* <---- +-+ +-+ +-----------+ +--------+
* dequeue buffers \-------------------/\--------/
* graph internal
* latency latency
* \--------/\-------------/\-----------------------------/
* queued buffered delay
*\endcode
*/
struct pw_time {
int64_t now; /**< the monotonic time in nanoseconds. This is the time
* when this time report was updated. It is usually
* updated every graph cycle. You can use the current
* monotonic time to calculate the elapsed time between
* this report and the current state and calculate
* updated ticks and delay values. */
struct spa_fraction rate; /**< the rate of \a ticks and delay. This is usually
* expressed in 1/<samplerate>. */
uint64_t ticks; /**< the ticks at \a now. This is the current time that
* the remote end is reading/writing. This is monotonicaly
* increasing. */
int64_t delay; /**< delay to device. This is the time it will take for
* the next output sample of the stream to be presented by
* the playback device or the time a sample traveled
* from the capture device. This delay includes the
* delay introduced by all filters on the path between
* the stream and the device. The delay is normally
* constant in a graph and can change when the topology
* of the graph or the quantum changes. This delay does
* not include the delay caused by queued buffers. */
uint64_t queued; /**< data queued in the stream, this is the sum
* of the size fields in the pw_buffer that are
* currently queued */
uint64_t buffered; /**< for audio/raw streams, this contains the extra
* number of samples buffered in the resampler.
* Since 0.3.50. */
uint32_t queued_buffers; /**< The number of buffers that are queued. Since 0.3.50 */
uint32_t avail_buffers; /**< The number of buffers that can be dequeued. Since 0.3.50 */
};
#include <pipewire/port.h>
/** Events for a stream. These events are always called from the mainloop
* unless explicitly documented otherwise. */
struct pw_stream_events {
#define PW_VERSION_STREAM_EVENTS 2
uint32_t version;
void (*destroy) (void *data);
/** when the stream state changes */
void (*state_changed) (void *data, enum pw_stream_state old,
enum pw_stream_state state, const char *error);
/** Notify information about a control. */
void (*control_info) (void *data, uint32_t id, const struct pw_stream_control *control);
/** when io changed on the stream. */
void (*io_changed) (void *data, uint32_t id, void *area, uint32_t size);
/** when a parameter changed */
void (*param_changed) (void *data, uint32_t id, const struct spa_pod *param);
/** when a new buffer was created for this stream */
void (*add_buffer) (void *data, struct pw_buffer *buffer);
/** when a buffer was destroyed for this stream */
void (*remove_buffer) (void *data, struct pw_buffer *buffer);
/** when a buffer can be queued (for playback streams) or
* dequeued (for capture streams). This is normally called from the
* mainloop but can also be called directly from the realtime data
* thread if the user is prepared to deal with this. */
void (*process) (void *data);
/** The stream is drained */
void (*drained) (void *data);
/** A command notify, Since 0.3.39:1 */
void (*command) (void *data, const struct spa_command *command);
/** a trigger_process completed. Since version 0.3.40:2 */
void (*trigger_done) (void *data);
};
/** Convert a stream state to a readable string */
const char * pw_stream_state_as_string(enum pw_stream_state state);
/** \enum pw_stream_flags Extra flags that can be used in \ref pw_stream_connect() */
enum pw_stream_flags {
PW_STREAM_FLAG_NONE = 0, /**< no flags */
PW_STREAM_FLAG_AUTOCONNECT = (1 << 0), /**< try to automatically connect
* this stream */
PW_STREAM_FLAG_INACTIVE = (1 << 1), /**< start the stream inactive,
* pw_stream_set_active() needs to be
* called explicitly */
PW_STREAM_FLAG_MAP_BUFFERS = (1 << 2), /**< mmap the buffers except DmaBuf */
PW_STREAM_FLAG_DRIVER = (1 << 3), /**< be a driver */
PW_STREAM_FLAG_RT_PROCESS = (1 << 4), /**< call process from the realtime
* thread. You MUST use RT safe functions
* in the process callback. */
PW_STREAM_FLAG_NO_CONVERT = (1 << 5), /**< don't convert format */
PW_STREAM_FLAG_EXCLUSIVE = (1 << 6), /**< require exclusive access to the
* device */
PW_STREAM_FLAG_DONT_RECONNECT = (1 << 7), /**< don't try to reconnect this stream
* when the sink/source is removed */
PW_STREAM_FLAG_ALLOC_BUFFERS = (1 << 8), /**< the application will allocate buffer
* memory. In the add_buffer event, the
* data of the buffer should be set */
PW_STREAM_FLAG_TRIGGER = (1 << 9), /**< the output stream will not be scheduled
* automatically but _trigger_process()
* needs to be called. This can be used
* when the output of the stream depends
* on input from other streams. */
PW_STREAM_FLAG_ASYNC = (1 << 10), /**< Buffers will not be dequeued/queued from
* the realtime process() function. This is
* assumed when RT_PROCESS is unset but can
* also be the case when the process() function
* does a trigger_process() that will then
* dequeue/queue a buffer from another process()
* function. since 0.3.73 */
PW_STREAM_FLAG_EARLY_PROCESS = (1 << 11), /**< Call process as soon as there is a buffer
* to dequeue. This is only relevant for
* playback and when not using RT_PROCESS. It
* can be used to keep the maximum number of
* buffers queued. Since 0.3.81 */
};
/** Create a new unconneced \ref pw_stream
* \return a newly allocated \ref pw_stream */
struct pw_stream *
pw_stream_new(struct pw_core *core, /**< a \ref pw_core */
const char *name, /**< a stream media name */
struct pw_properties *props /**< stream properties, ownership is taken */);
struct pw_stream *
pw_stream_new_simple(struct pw_loop *loop, /**< a \ref pw_loop to use */
const char *name, /**< a stream media name */
struct pw_properties *props,/**< stream properties, ownership is taken */
const struct pw_stream_events *events, /**< stream events */
void *data /**< data passed to events */);
/** Destroy a stream */
void pw_stream_destroy(struct pw_stream *stream);
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_properties *pw_stream_get_properties(struct pw_stream *stream);
int pw_stream_update_properties(struct pw_stream *stream, const struct spa_dict *dict);
/** Connect a stream for input or output on \a port_path.
* \return 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. */
int
pw_stream_connect(struct pw_stream *stream, /**< a \ref pw_stream */
enum pw_direction direction, /**< the stream direction */
uint32_t target_id, /**< should have the value PW_ID_ANY.
* To select a specific target
* node, specify the
* PW_KEY_OBJECT_SERIAL or the
* PW_KEY_NODE_NAME value of the target
* node in the PW_KEY_TARGET_OBJECT
* property of the stream.
* Specifying target nodes by
* their id is deprecated.
*/
enum pw_stream_flags flags, /**< stream flags */
const struct spa_pod **params, /**< an array with params. The params
* should ideally contain supported
* formats. */
uint32_t n_params /**< number of items in \a params */);
/** Get the node ID of the stream.
* \return node ID. */
uint32_t
pw_stream_get_node_id(struct pw_stream *stream);
/** Disconnect \a stream */
int pw_stream_disconnect(struct pw_stream *stream);
/** Set the stream in error state */
int pw_stream_set_error(struct pw_stream *stream, /**< a \ref pw_stream */
int res, /**< a result code */
const char *error, /**< an error message */
...) SPA_PRINTF_FUNC(3, 4);
/** Update the param exposed on the stream. */
int
pw_stream_update_params(struct pw_stream *stream, /**< a \ref pw_stream */
const struct spa_pod **params, /**< an array of params. */
uint32_t n_params /**< number of elements in \a params */);
/**
* Set a parameter on the stream. This is like pw_stream_set_control() but with
* a complete spa_pod param. It can also be called from the param_changed event handler
* to intercept and modify the param for the adapter. Since 0.3.70 */
int pw_stream_set_param(struct pw_stream *stream, /**< a \ref pw_stream */
uint32_t id, /**< the id of the param */
const struct spa_pod *param /**< the params to set */);
/** Get control values */
const struct pw_stream_control *pw_stream_get_control(struct pw_stream *stream, uint32_t id);
/** Set control values */
int pw_stream_set_control(struct pw_stream *stream, uint32_t id, uint32_t n_values, float *values, ...);
/** Query the time on the stream */
int pw_stream_get_time_n(struct pw_stream *stream, struct pw_time *time, size_t size);
/** Query the time on the stream, deprecated since 0.3.50,
* use pw_stream_get_time_n() to get the fields added since 0.3.50. */
SPA_DEPRECATED
int pw_stream_get_time(struct pw_stream *stream, struct pw_time *time);
/** Get a buffer that can be filled for playback streams or consumed
* for capture streams. */
struct pw_buffer *pw_stream_dequeue_buffer(struct pw_stream *stream);
/** Submit a buffer for playback or recycle a buffer for capture. */
int pw_stream_queue_buffer(struct pw_stream *stream, struct pw_buffer *buffer);
/** Activate or deactivate the stream */
int pw_stream_set_active(struct pw_stream *stream, bool active);
/** Flush a stream. When \a drain is true, the drained callback will
* be called when all data is played or recorded */
int pw_stream_flush(struct pw_stream *stream, bool drain);
/** 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 */
bool pw_stream_is_driving(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 */
int pw_stream_trigger_process(struct pw_stream *stream);
/**
* \}
*/
#ifdef __cplusplus
}
#endif
#endif /* PIPEWIRE_STREAM_H */