Class pipeline

• Defined in File rs_pipeline.hpp

Class Documentation

class pipeline

The pipeline simplifies the user interaction with the device and computer vision processing modules. The class abstracts the camera configuration and streaming, and the vision modules triggering and threading. It lets the application focus on the computer vision output of the modules, or the device output data. The pipeline can manage computer vision modules, which are implemented as a processing blocks. The pipeline is the consumer of the processing block interface, while the application consumes the computer vision interface.

Public Functions

inline pipeline(context ctx = context())

Create a pipeline for processing data from a single device. The caller can provide a context created by the application, usually for playback or testing purposes.

Parameters:

ctx – [in] The context allocated by the application. Using the platform context by default.

inline pipeline_profile start()

Start the pipeline streaming with its default configuration. The pipeline streaming loop captures samples from the device, and delivers them to the attached computer vision modules and processing blocks, according to each module requirements and threading model. During the loop execution, the application can access the camera streams by calling wait_for_frames() or poll_for_frames(). The streaming loop runs until the pipeline is stopped. Starting the pipeline is possible only when it is not started. If the pipeline was started, an exception is raised.

Returns:

The actual pipeline device and streams profile, which was successfully configured to the streaming device.

inline pipeline_profile start(const config &config)

Start the pipeline streaming according to the configuraion. The pipeline streaming loop captures samples from the device, and delivers them to the attached computer vision modules and processing blocks, according to each module requirements and threading model. During the loop execution, the application can access the camera streams by calling wait_for_frames() or poll_for_frames(). The streaming loop runs until the pipeline is stopped. Starting the pipeline is possible only when it is not started. If the pipeline was started, an exception is raised. The pipeline selects and activates the device upon start, according to configuration or a default configuration. When the rs2::config is provided to the method, the pipeline tries to activate the config resolve() result. If the application requests are conflicting with pipeline computer vision modules or no matching device is available on the platform, the method fails. Available configurations and devices may change between config resolve() call and pipeline start, in case devices are connected or disconnected, or another application acquires ownership of a device.

Parameters:

config – [in] A rs2::config with requested filters on the pipeline configuration. By default no filters are applied.

Returns:

The actual pipeline device and streams profile, which was successfully configured to the streaming device.

template<class S>
inline pipeline_profile start(S callback)

Start the pipeline streaming with its default configuration. The pipeline captures samples from the device, and delivers them to the provided frame callback. Starting the pipeline is possible only when it is not started. If the pipeline was started, an exception is raised. When starting the pipeline with a callback both wait_for_frames() and poll_for_frames() will throw exception.

Parameters:

callback – [in] Stream callback, can be any callable object accepting rs2::frame

Returns:

The actual pipeline device and streams profile, which was successfully configured to the streaming device.

template<class S>
inline pipeline_profile start(const config &config, S callback)

Start the pipeline streaming according to the configuraion. The pipeline captures samples from the device, and delivers them to the provided frame callback. Starting the pipeline is possible only when it is not started. If the pipeline was started, an exception is raised. When starting the pipeline with a callback both wait_for_frames() and poll_for_frames() will throw exception. The pipeline selects and activates the device upon start, according to configuration or a default configuration. When the rs2::config is provided to the method, the pipeline tries to activate the config resolve() result. If the application requests are conflicting with pipeline computer vision modules or no matching device is available on the platform, the method fails. Available configurations and devices may change between config resolve() call and pipeline start, in case devices are connected or disconnected, or another application acquires ownership of a device.

Parameters:

• config – [in] A rs2::config with requested filters on the pipeline configuration. By default no filters are applied.

• callback – [in] Stream callback, can be any callable object accepting rs2::frame

Returns:

The actual pipeline device and streams profile, which was successfully configured to the streaming device.

inline void stop()

Stop the pipeline streaming. The pipeline stops delivering samples to the attached computer vision modules and processing blocks, stops the device streaming and releases the device resources used by the pipeline. It is the application’s responsibility to release any frame reference it owns. The method takes effect only after start() was called, otherwise an exception is raised.

inline frameset wait_for_frames(unsigned int timeout_ms = RS2_DEFAULT_TIMEOUT) const

Wait until a new set of frames becomes available. The frames set includes time-synchronized frames of each enabled stream in the pipeline. In case of different frame rates of the streams, the frames set include a matching frame of the slow stream, which may have been included in previous frames set. The method blocks the calling thread, and fetches the latest unread frames set. Device frames, which were produced while the function wasn’t called, are dropped. To avoid frame drops, this method should be called as fast as the device frame rate. The application can maintain the frames handles to defer processing. However, if the application maintains too long history, the device may lack memory resources to produce new frames, and the following call to this method shall fail to retrieve new frames, until resources become available.

Parameters:

timeout_ms – [in] Max time in milliseconds to wait until an exception will be thrown

Returns:

Set of time synchronized frames, one from each active stream

inline bool poll_for_frames(frameset *f) const

Check if a new set of frames is available and retrieve the latest undelivered set. The frames set includes time-synchronized frames of each enabled stream in the pipeline. The method returns without blocking the calling thread, with status of new frames available or not. If available, it fetches the latest frames set. Device frames, which were produced while the function wasn’t called, are dropped. To avoid frame drops, this method should be called as fast as the device frame rate. The application can maintain the frames handles to defer processing. However, if the application maintains too long history, the device may lack memory resources to produce new frames, and the following calls to this method shall return no new frames, until resources become available.

Parameters:

f – [out] Frames set handle

Returns:

True if new set of time synchronized frames was stored to f, false if no new frames set is available

inline bool try_wait_for_frames(frameset *f, unsigned int timeout_ms = RS2_DEFAULT_TIMEOUT) const

inline pipeline_profile get_active_profile() const

Return the active device and streams profiles, used by the pipeline. The pipeline streams profiles are selected during start(). The method returns a valid result only when the pipeline is active - between calls to start() and stop(). After stop() is called, the pipeline doesn’t own the device, thus, the pipeline selected device may change in subsequent activations.

Returns:

The actual pipeline device and streams profile, which was successfully configured to the streaming device on start.

inline operator std::shared_ptr<rs2_pipeline>() const

inline explicit pipeline(std::shared_ptr<rs2_pipeline> ptr)