wpi::cs::RawSink Class Reference

A sink for user code to accept video frames as raw bytes. More...

#include <wpi/cs/RawSink.hpp>

Inheritance diagram for wpi::cs::RawSink:

Public Member Functions
	RawSink ()=default
	RawSink (std::string_view name)
	Create a sink for accepting raw images.
	RawSink (std::string_view name, std::function< void(uint64_t time)> processFrame)
	Create a sink for accepting raws images in a separate thread.
Public Member Functions inherited from wpi::cs::ImageSink
void	SetDescription (std::string_view description)
	Set sink description.
std::string	GetError () const
	Get error string.
void	SetEnabled (bool enabled)
	Enable or disable getting new frames.
Public Member Functions inherited from wpi::cs::VideoSink
	VideoSink () noexcept=default
	VideoSink (const VideoSink &sink)
	VideoSink (VideoSink &&other) noexcept
VideoSink &	operator= (VideoSink other) noexcept
	~VideoSink ()
	operator bool () const
	Returns true if the VideoSink is valid.
int	GetHandle () const
	Returns the VideoSink handle.
bool	operator== (const VideoSink &other) const
Kind	GetKind () const
	Get the kind of the sink.
std::string	GetName () const
	Get the name of the sink.
std::string	GetDescription () const
	Get the sink description.
VideoProperty	GetProperty (std::string_view name)
	Get a property of the sink.
std::vector< VideoProperty >	EnumerateProperties () const
	Enumerate all properties of this sink.
bool	SetConfigJson (std::string_view config)
	Set properties from a JSON configuration string.
bool	SetConfigJson (const wpi::util::json &config)
	Set properties from a JSON configuration object.
std::string	GetConfigJson () const
	Get a JSON configuration string.
wpi::util::json	GetConfigJsonObject () const
	Get a JSON configuration object.
void	SetSource (VideoSource source)
	Configure which source should provide frames to this sink.
VideoSource	GetSource () const
	Get the connected source.
VideoProperty	GetSourceProperty (std::string_view name)
	Get a property of the associated source.
CS_Status	GetLastStatus () const

Protected Member Functions
uint64_t	GrabFrame (wpi::util::RawFrame &image, double timeout=0.225) const
	Wait for the next frame and get the image.
uint64_t	GrabFrameNoTimeout (wpi::util::RawFrame &image) const
	Wait for the next frame and get the image.
uint64_t	GrabFrameLastTime (wpi::util::RawFrame &image, uint64_t lastFrameTime, double timeout=0.225) const
	Wait for the next frame and get the image.
Protected Member Functions inherited from wpi::cs::ImageSink
	ImageSink ()=default
Protected Member Functions inherited from wpi::cs::VideoSink
	VideoSink (CS_Sink handle)

Additional Inherited Members
Public Types inherited from wpi::cs::VideoSink
enum	Kind { kUnknown = CS_SINK_UNKNOWN , kMjpeg = CS_SINK_MJPEG , kCv = CS_SINK_CV , kRaw = CS_SINK_RAW }
Static Public Member Functions inherited from wpi::cs::VideoSink
static std::vector< VideoSink >	EnumerateSinks ()
	Enumerate all existing sinks.
Protected Attributes inherited from wpi::cs::VideoSink
CS_Status	m_status = 0
CS_Sink	m_handle {0}

Detailed Description

A sink for user code to accept video frames as raw bytes.

This is a complex API, most cases should use CvSource.

Constructor & Destructor Documentation

RawSink() [1/3]

wpi::cs::RawSink::RawSink ( )

default

RawSink() [2/3]

wpi::cs::RawSink::RawSink ( std::string_view name )

inlineexplicit

Create a sink for accepting raw images.

GrabFrame() must be called on the created sink to get each new image.

Parameters

name	Source name (arbitrary unique identifier)

RawSink() [3/3]

wpi::cs::RawSink::RawSink ( std::string_view name, std::function< void(uint64_t time)> processFrame )

inline

Create a sink for accepting raws images in a separate thread.

A thread will be created that calls WaitForFrame() and calls the processFrame() callback each time a new frame arrives.

Parameters

name	Source name (arbitrary unique identifier)
processFrame	Frame processing function; will be called with a time=0 if an error occurred. processFrame should call GetImage() or GetError() as needed, but should not call (except in very unusual circumstances) WaitForImage().

Member Function Documentation

GrabFrame()

uint64_t wpi::cs::RawSink::GrabFrame ( wpi::util::RawFrame & image, double timeout = 0.225 ) const

inlinenodiscardprotected

Wait for the next frame and get the image.

Times out (returning 0) after timeout seconds. The provided image will have three 8-bit channels stored in BGR order.

Returns

Frame time, or 0 on error (call GetError() to obtain the error message); the frame time is in the same time base as wpi::util::Now(), and is in 1 us increments.

GrabFrameLastTime()

uint64_t wpi::cs::RawSink::GrabFrameLastTime ( wpi::util::RawFrame & image, uint64_t lastFrameTime, double timeout = 0.225 ) const

inlinenodiscardprotected

Wait for the next frame and get the image.

May block forever. The provided image will have three 8-bit channels stored in BGR order.

If lastFrameTime is provided and non-zero, the sink will fill image with the first frame from the source that is not equal to lastFrameTime. If lastFrameTime is zero, the time of the current frame owned by the CvSource is used, and this function will block until the connected CvSource provides a new frame.

Returns

Frame time, or 0 on error (call GetError() to obtain the error message); the frame time is in the same time base as wpi::util::Now(), and is in 1 us increments.

GrabFrameNoTimeout()

uint64_t wpi::cs::RawSink::GrabFrameNoTimeout ( wpi::util::RawFrame & image ) const

inlinenodiscardprotected

Wait for the next frame and get the image.

May block forever. The provided image will have three 8-bit channels stored in BGR order.

Returns

Frame time, or 0 on error (call GetError() to obtain the error message); the frame time is in the same time base as wpi::util::Now(), and is in 1 us increments.

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The documentation for this class was generated from the following file:

• wpi/cs/RawSink.hpp