513 lines
20 KiB
C
513 lines
20 KiB
C
/* PipeWire */
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/* SPDX-FileCopyrightText: Copyright © 2018 Wim Taymans */
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/* SPDX-License-Identifier: MIT */
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#ifndef PIPEWIRE_STREAM_H
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#define PIPEWIRE_STREAM_H
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#ifdef __cplusplus
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extern "C" {
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#endif
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/** \page page_streams Streams
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*
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* \section sec_overview Overview
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*
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* \ref pw_stream "Streams" are used to exchange data with the
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* PipeWire server. A stream is a wrapper around a proxy for a pw_client_node
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* with an adapter. This means the stream will automatically do conversion
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* to the type required by the server.
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*
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* Streams can be used to:
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*
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* \li Consume a stream from PipeWire. This is a PW_DIRECTION_INPUT stream.
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* \li Produce a stream to PipeWire. This is a PW_DIRECTION_OUTPUT stream
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*
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* You can connect the stream port to a specific server port or let PipeWire
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* choose a port for you.
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*
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* For more complicated nodes such as filters or ports with multiple
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* inputs and/or outputs you will need to use the pw_filter or make
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* a pw_node yourself and export it with \ref pw_core_export.
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*
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* Streams can also be used to:
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*
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* \li Implement a Sink in PipeWire. This is a PW_DIRECTION_INPUT stream.
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* \li Implement a Source in PipeWire. This is a PW_DIRECTION_OUTPUT stream
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*
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* In this case, the PW_KEY_MEDIA_CLASS property needs to be set to
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* "Audio/Sink" or "Audio/Source" respectively.
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*
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* \section sec_create Create
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*
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* Make a new stream with \ref pw_stream_new(). You will need to specify
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* a name for the stream and extra properties. The basic set of properties
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* each stream must provide is filled in automatically.
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*
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* Once the stream is created, the state_changed event should be used to
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* track the state of the stream.
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*
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* \section sec_connect Connect
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*
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* The stream is initially unconnected. To connect the stream, use
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* \ref pw_stream_connect(). Pass the desired direction as an argument.
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*
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* The direction is:
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* \li PW_DIRECTION_INPUT for a stream that *consumes* data. This can be a
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* stream that captures from a Source or a when the stream is used to
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* implement a Sink.
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*
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* \li PW_DIRECTION_OUTPUT for a stream that *produces* data. This can be a
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* stream that plays to a Sink or when the stream is used to implement
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* a Source.
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*
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* \subsection ssec_stream_target Stream target
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*
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* To make the newly connected stream automatically connect to an existing
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* PipeWire node, use the \ref PW_STREAM_FLAG_AUTOCONNECT and set the
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* PW_KEY_OBJECT_SERIAL or the PW_KEY_NODE_NAME value of the target node
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* in the PW_KEY_TARGET_OBJECT property before connecting.
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*
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* \subsection ssec_stream_formats Stream formats
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*
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* An array of possible formats that this stream can consume or provide
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* must be specified.
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*
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* \section sec_format Format negotiation
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*
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* After connecting the stream, the server will want to configure some
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* parameters on the stream. You will be notified of these changes
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* with the param_changed event.
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*
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* When a format param change is emitted, the client should now prepare
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* itself to deal with the format and complete the negotiation procedure
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* with a call to \ref pw_stream_update_params().
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*
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* As arguments to \ref pw_stream_update_params() an array of spa_param
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* structures must be given. They contain parameters such as buffer size,
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* number of buffers, required metadata and other parameters for the
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* media buffers.
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*
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* \section sec_buffers Buffer negotiation
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*
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* After completing the format negotiation, PipeWire will allocate and
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* notify the stream of the buffers that will be used to exchange data
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* between client and server.
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*
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* With the add_buffer event, a stream will be notified of a new buffer
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* that can be used for data transport. You can attach user_data to these
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* buffers. The buffers can only be used with the stream that emitted
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* the add_buffer event.
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*
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* After the buffers are negotiated, the stream will transition to the
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* \ref PW_STREAM_STATE_PAUSED state.
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*
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* \section sec_streaming Streaming
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*
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* From the \ref PW_STREAM_STATE_PAUSED state, the stream can be set to
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* the \ref PW_STREAM_STATE_STREAMING state by the PipeWire server when
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* data transport is started.
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*
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* Depending on how the stream was connected it will need to Produce or
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* Consume data for/from PipeWire as explained in the following
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* subsections.
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*
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* \subsection ssec_consume Consume data
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*
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* The process event is emitted for each new buffer that can be
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* consumed.
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*
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* \ref pw_stream_dequeue_buffer() should be used to get the data and
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* metadata of the buffer.
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*
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* The buffer is owned by the stream and stays alive until the
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* remove_buffer callback has returned or the stream is destroyed.
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*
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* When the buffer has been processed, call \ref pw_stream_queue_buffer()
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* to let PipeWire reuse the buffer.
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*
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* \subsection ssec_produce Produce data
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*
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* \ref pw_stream_dequeue_buffer() gives an empty buffer that can be filled.
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*
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* The buffer is owned by the stream and stays alive until the
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* remove_buffer event is emitted or the stream is destroyed.
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*
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* Filled buffers should be queued with \ref pw_stream_queue_buffer().
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*
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* The process event is emitted when PipeWire has emptied a buffer that
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* can now be refilled.
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*
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* \section sec_stream_disconnect Disconnect
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*
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* Use \ref pw_stream_disconnect() to disconnect a stream after use.
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*
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* \section sec_stream_configuration Configuration
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*
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* \subsection ssec_config_properties Stream Properties
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*
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* \subsection ssec_config_rules Stream Rules
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*
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* \section sec_stream_environment Environment Variables
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*
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*/
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/** \defgroup pw_stream Stream
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*
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* \brief PipeWire stream objects
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*
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* The stream object provides a convenient way to send and
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* receive data streams from/to PipeWire.
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*
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* See also \ref page_streams and \ref api_pw_core
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*/
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/**
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* \addtogroup pw_stream
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* \{
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*/
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struct pw_stream;
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#include <spa/buffer/buffer.h>
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#include <spa/param/param.h>
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#include <spa/pod/command.h>
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/** \enum pw_stream_state The state of a stream */
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enum pw_stream_state {
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PW_STREAM_STATE_ERROR = -1, /**< the stream is in error */
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PW_STREAM_STATE_UNCONNECTED = 0, /**< unconnected */
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PW_STREAM_STATE_CONNECTING = 1, /**< connection is in progress */
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PW_STREAM_STATE_PAUSED = 2, /**< paused */
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PW_STREAM_STATE_STREAMING = 3 /**< streaming */
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};
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/** a buffer structure obtained from pw_stream_dequeue_buffer(). The size of this
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* structure can grow as more field are added in the future */
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struct pw_buffer {
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struct spa_buffer *buffer; /**< the spa buffer */
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void *user_data; /**< user data attached to the buffer */
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uint64_t size; /**< This field is set by the user and the sum of
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* all queued buffer is returned in the time info.
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* For audio, it is advised to use the number of
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* samples in the buffer for this field. */
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uint64_t requested; /**< For playback streams, this field contains the
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* suggested amount of data to provide. For audio
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* streams this will be the amount of samples
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* required by the resampler. This field is 0
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* when no suggestion is provided. Since 0.3.49 */
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};
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struct pw_stream_control {
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const char *name; /**< name of the control */
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uint32_t flags; /**< extra flags (unused) */
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float def; /**< default value */
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float min; /**< min value */
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float max; /**< max value */
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float *values; /**< array of values */
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uint32_t n_values; /**< number of values in array */
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uint32_t max_values; /**< max values that can be set on this control */
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};
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/** A time structure.
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*
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* Use pw_stream_get_time_n() to get an updated time snapshot of the stream.
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* The time snapshot can give information about the time in the driver of the
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* graph, the delay to the edge of the graph and the internal queuing in the
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* stream.
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*
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* pw_time.ticks gives a monotonic increasing counter of the time in the graph
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* driver. I can be used to generate a timetime to schedule samples as well
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* as detect discontinuities in the timeline caused by xruns.
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*
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* pw_time.delay is expressed as pw_time.rate, the time domain of the graph. This
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* value, and pw_time.ticks, were captured at pw_time.now and can be extrapolated
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* to the current time like this:
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*
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* struct timespec ts;
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* clock_gettime(CLOCK_MONOTONIC, &ts);
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* int64_t diff = SPA_TIMESPEC_TO_NSEC(&ts) - pw_time.now;
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* int64_t elapsed = (pw_time.rate.denom * diff) / (pw_time.rate.num * SPA_NSEC_PER_SEC);
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*
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* pw_time.delay contains the total delay that a signal will travel through the
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* graph. This includes the delay caused by filters in the graph as well as delays
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* caused by the hardware. The delay is usually quite stable and should only change when
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* the topology, quantum or samplerate of the graph changes.
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*
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* pw_time.queued and pw_time.buffered is expressed in the time domain of the stream,
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* or the format that is used for the buffers of this stream.
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*
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* pw_time.queued is the sum of all the pw_buffer.size fields of the buffers that are
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* currently queued in the stream but not yet processed. The application can choose
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* the units of this value, for example, time, samples or bytes (below expressed
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* as app.rate).
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*
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* pw_time.buffered is format dependent, for audio/raw it contains the number of samples
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* that are buffered inside the resampler/converter.
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*
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* The total delay of data in a stream is the sum of the queued and buffered data
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* (not yet processed data) and the delay to the edge of the graph, usually a
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* playback or capture device.
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*
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* For an audio playback stream, if you were to queue a buffer, the total delay
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* in milliseconds for the first sample in the newly queued buffer to be played
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* by the hardware can be calculated as:
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*
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* (pw_time.buffered * 1000 / stream.samplerate) +
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* (pw_time.queued * 1000 / app.rate) +
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* ((pw_time.delay - elapsed) * 1000 * pw_time.rate.num / pw_time.rate.denom)
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*
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* The current extrapolated time (in ms) in the source or sink can be calculated as:
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*
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* (pw_time.ticks + elapsed) * 1000 * pw_time.rate.num / pw_time.rate.denom
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*
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*
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* stream time domain graph time domain
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* /-----------------------\/-----------------------------\
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*
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* queue +-+ +-+ +-----------+ +--------+
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* ----> | | | |->| converter | -> graph -> | kernel | -> speaker
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* <---- +-+ +-+ +-----------+ +--------+
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* dequeue buffers \-------------------/\--------/
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* graph internal
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* latency latency
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* \--------/\-------------/\-----------------------------/
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* queued buffered delay
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*/
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struct pw_time {
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int64_t now; /**< the monotonic time in nanoseconds. This is the time
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* when this time report was updated. It is usually
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* updated every graph cycle. You can use the current
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* monotonic time to calculate the elapsed time between
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* this report and the current state and calculate
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* updated ticks and delay values. */
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struct spa_fraction rate; /**< the rate of \a ticks and delay. This is usually
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* expressed in 1/<samplerate>. */
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uint64_t ticks; /**< the ticks at \a now. This is the current time that
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* the remote end is reading/writing. This is monotonicaly
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* increasing. */
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int64_t delay; /**< delay to device. This is the time it will take for
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* the next output sample of the stream to be presented by
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* the playback device or the time a sample traveled
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* from the capture device. This delay includes the
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* delay introduced by all filters on the path between
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* the stream and the device. The delay is normally
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* constant in a graph and can change when the topology
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* of the graph or the quantum changes. This delay does
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* not include the delay caused by queued buffers. */
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uint64_t queued; /**< data queued in the stream, this is the sum
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* of the size fields in the pw_buffer that are
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* currently queued */
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uint64_t buffered; /**< for audio/raw streams, this contains the extra
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* number of samples buffered in the resampler.
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* Since 0.3.50. */
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uint32_t queued_buffers; /**< The number of buffers that are queued. Since 0.3.50 */
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uint32_t avail_buffers; /**< The number of buffers that can be dequeued. Since 0.3.50 */
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};
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#include <pipewire/port.h>
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/** Events for a stream. These events are always called from the mainloop
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* unless explicitly documented otherwise. */
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struct pw_stream_events {
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#define PW_VERSION_STREAM_EVENTS 2
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uint32_t version;
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void (*destroy) (void *data);
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/** when the stream state changes */
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void (*state_changed) (void *data, enum pw_stream_state old,
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enum pw_stream_state state, const char *error);
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/** Notify information about a control. */
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void (*control_info) (void *data, uint32_t id, const struct pw_stream_control *control);
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/** when io changed on the stream. */
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void (*io_changed) (void *data, uint32_t id, void *area, uint32_t size);
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/** when a parameter changed */
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void (*param_changed) (void *data, uint32_t id, const struct spa_pod *param);
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/** when a new buffer was created for this stream */
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void (*add_buffer) (void *data, struct pw_buffer *buffer);
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/** when a buffer was destroyed for this stream */
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void (*remove_buffer) (void *data, struct pw_buffer *buffer);
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/** when a buffer can be queued (for playback streams) or
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* dequeued (for capture streams). This is normally called from the
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* mainloop but can also be called directly from the realtime data
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* thread if the user is prepared to deal with this. */
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void (*process) (void *data);
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/** The stream is drained */
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void (*drained) (void *data);
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/** A command notify, Since 0.3.39:1 */
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void (*command) (void *data, const struct spa_command *command);
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/** a trigger_process completed. Since version 0.3.40:2 */
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void (*trigger_done) (void *data);
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};
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/** Convert a stream state to a readable string */
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const char * pw_stream_state_as_string(enum pw_stream_state state);
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/** \enum pw_stream_flags Extra flags that can be used in \ref pw_stream_connect() */
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enum pw_stream_flags {
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PW_STREAM_FLAG_NONE = 0, /**< no flags */
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PW_STREAM_FLAG_AUTOCONNECT = (1 << 0), /**< try to automatically connect
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* this stream */
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PW_STREAM_FLAG_INACTIVE = (1 << 1), /**< start the stream inactive,
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* pw_stream_set_active() needs to be
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* called explicitly */
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PW_STREAM_FLAG_MAP_BUFFERS = (1 << 2), /**< mmap the buffers except DmaBuf */
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PW_STREAM_FLAG_DRIVER = (1 << 3), /**< be a driver */
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PW_STREAM_FLAG_RT_PROCESS = (1 << 4), /**< call process from the realtime
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* thread. You MUST use RT safe functions
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* in the process callback. */
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PW_STREAM_FLAG_NO_CONVERT = (1 << 5), /**< don't convert format */
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PW_STREAM_FLAG_EXCLUSIVE = (1 << 6), /**< require exclusive access to the
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* device */
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PW_STREAM_FLAG_DONT_RECONNECT = (1 << 7), /**< don't try to reconnect this stream
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* when the sink/source is removed */
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PW_STREAM_FLAG_ALLOC_BUFFERS = (1 << 8), /**< the application will allocate buffer
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* memory. In the add_buffer event, the
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* data of the buffer should be set */
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PW_STREAM_FLAG_TRIGGER = (1 << 9), /**< the output stream will not be scheduled
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* automatically but _trigger_process()
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* needs to be called. This can be used
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* when the output of the stream depends
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* on input from other streams. */
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};
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/** Create a new unconneced \ref pw_stream
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* \return a newly allocated \ref pw_stream */
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struct pw_stream *
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pw_stream_new(struct pw_core *core, /**< a \ref pw_core */
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const char *name, /**< a stream media name */
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struct pw_properties *props /**< stream properties, ownership is taken */);
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struct pw_stream *
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pw_stream_new_simple(struct pw_loop *loop, /**< a \ref pw_loop to use */
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const char *name, /**< a stream media name */
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struct pw_properties *props,/**< stream properties, ownership is taken */
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const struct pw_stream_events *events, /**< stream events */
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void *data /**< data passed to events */);
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/** Destroy a stream */
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void pw_stream_destroy(struct pw_stream *stream);
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void pw_stream_add_listener(struct pw_stream *stream,
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struct spa_hook *listener,
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const struct pw_stream_events *events,
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void *data);
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enum pw_stream_state pw_stream_get_state(struct pw_stream *stream, const char **error);
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const char *pw_stream_get_name(struct pw_stream *stream);
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struct pw_core *pw_stream_get_core(struct pw_stream *stream);
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const struct pw_properties *pw_stream_get_properties(struct pw_stream *stream);
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int pw_stream_update_properties(struct pw_stream *stream, const struct spa_dict *dict);
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/** Connect a stream for input or output on \a port_path.
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* \return 0 on success < 0 on error.
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*
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* You should connect to the process event and use pw_stream_dequeue_buffer()
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* to get the latest metadata and data. */
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int
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pw_stream_connect(struct pw_stream *stream, /**< a \ref pw_stream */
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enum pw_direction direction, /**< the stream direction */
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uint32_t target_id, /**< should have the value PW_ID_ANY.
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* To select a specific target
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* node, specify the
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* PW_KEY_OBJECT_SERIAL or the
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* PW_KEY_NODE_NAME value of the target
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* node in the PW_KEY_TARGET_OBJECT
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* property of the stream.
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* Specifying target nodes by
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* their id is deprecated.
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*/
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enum pw_stream_flags flags, /**< stream flags */
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const struct spa_pod **params, /**< an array with params. The params
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* should ideally contain supported
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* formats. */
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uint32_t n_params /**< number of items in \a params */);
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/** Get the node ID of the stream.
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* \return node ID. */
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uint32_t
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pw_stream_get_node_id(struct pw_stream *stream);
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/** Disconnect \a stream */
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int pw_stream_disconnect(struct pw_stream *stream);
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/** Set the stream in error state */
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int pw_stream_set_error(struct pw_stream *stream, /**< a \ref pw_stream */
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int res, /**< a result code */
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const char *error, /**< an error message */
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...) SPA_PRINTF_FUNC(3, 4);
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/** Update the param exposed on the stream. */
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int
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pw_stream_update_params(struct pw_stream *stream, /**< a \ref pw_stream */
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const struct spa_pod **params, /**< an array of params. The params should
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* ideally contain parameters for doing
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* buffer allocation. */
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uint32_t n_params /**< number of elements in \a params */);
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/**
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* Set a parameter on the stream. This is like pw_stream_set_control() but with
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* a complete spa_pod param. It can also be called from the param_changed event handler
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* to intercept and modify the param for the adapter. Since 0.3.70 */
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int pw_stream_set_param(struct pw_stream *stream, /**< a \ref pw_stream */
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uint32_t id, /**< the id of the param */
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const struct spa_pod *param /**< the params to set */);
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/** Get control values */
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const struct pw_stream_control *pw_stream_get_control(struct pw_stream *stream, uint32_t id);
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/** Set control values */
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int pw_stream_set_control(struct pw_stream *stream, uint32_t id, uint32_t n_values, float *values, ...);
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/** Query the time on the stream */
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int pw_stream_get_time_n(struct pw_stream *stream, struct pw_time *time, size_t size);
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/** Query the time on the stream, deprecated since 0.3.50,
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* use pw_stream_get_time_n() to get the fields added since 0.3.50. */
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SPA_DEPRECATED
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int pw_stream_get_time(struct pw_stream *stream, struct pw_time *time);
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/** Get a buffer that can be filled for playback streams or consumed
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* for capture streams. */
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struct pw_buffer *pw_stream_dequeue_buffer(struct pw_stream *stream);
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/** Submit a buffer for playback or recycle a buffer for capture. */
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int pw_stream_queue_buffer(struct pw_stream *stream, struct pw_buffer *buffer);
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/** Activate or deactivate the stream */
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int pw_stream_set_active(struct pw_stream *stream, bool active);
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/** Flush a stream. When \a drain is true, the drained callback will
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* be called when all data is played or recorded */
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int pw_stream_flush(struct pw_stream *stream, bool drain);
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/** Check if the stream is driving. The stream needs to have the
|
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* PW_STREAM_FLAG_DRIVER set. When the stream is driving,
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* pw_stream_trigger_process() needs to be called when data is
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* available (output) or needed (input). Since 0.3.34 */
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bool pw_stream_is_driving(struct pw_stream *stream);
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/** Trigger a push/pull on the stream. One iteration of the graph will
|
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* scheduled and process() will be called. Since 0.3.34 */
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int pw_stream_trigger_process(struct pw_stream *stream);
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/**
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* \}
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*/
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#ifdef __cplusplus
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}
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#endif
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#endif /* PIPEWIRE_STREAM_H */
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