Package edu.wpi.first.cscore

Class VideoSource

java.lang.Object

edu.wpi.first.cscore.VideoSource

All Implemented Interfaces:

AutoCloseable

Direct Known Subclasses:

ImageSource, VideoCamera

public class VideoSource
extends Object
implements AutoCloseable

A source for video that provides a sequence of frames. Each frame may consist of multiple images (e.g. from a stereo or depth camera); these are called channels.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	VideoSource.ConnectionStrategy	Connection strategy.
static class	VideoSource.Kind

Field Summary

Fields

Modifier and Type	Field	Description
protected int	m_handle

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	VideoSource(int handle)

Method Summary

Modifier and Type	Method	Description
void	close()
VideoProperty[]	enumerateProperties()	Enumerate all properties of this source.
VideoSink[]	enumerateSinks()	Enumerate all sinks connected to this source.
static VideoSource[]	enumerateSources()	Enumerate all existing sources.
VideoMode[]	enumerateVideoModes()	Enumerate all known video modes for this source.
boolean	equals(Object other)
double	getActualDataRate()	Get the data rate (in bytes per second).
double	getActualFPS()	Get the actual FPS.
String	getConfigJson()	Get a JSON configuration string.
String	getDescription()	Get the source description.
int	getHandle()
VideoSource.Kind	getKind()	Get the kind of the source.
static VideoSource.Kind	getKindFromInt(int kind)	Convert from the numerical representation of kind to an enum type.
long	getLastFrameTime()	Get the last time a frame was captured.
String	getName()	Get the name of the source.
VideoProperty	getProperty(String name)	Get a property.
VideoMode	getVideoMode()	Get the current video mode.
int	hashCode()
boolean	isConnected()	Returns true if the source currently connected to whatever is providing the images.
boolean	isEnabled()	Gets source enable status.
boolean	isValid()
boolean	setConfigJson(String config)	Set video mode and properties from a JSON configuration string.
void	setConnectionStrategy(VideoSource.ConnectionStrategy strategy)	Sets the connection strategy.
boolean	setFPS(int fps)	Set the frames per second (FPS).
boolean	setPixelFormat(VideoMode.PixelFormat pixelFormat)	Set the pixel format.
boolean	setResolution(int width, int height)	Set the resolution.
boolean	setVideoMode(VideoMode mode)	Set the video mode.
boolean	setVideoMode(VideoMode.PixelFormat pixelFormat, int width, int height, int fps)	Set the video mode.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Field Details

m_handle

protected int m_handle

Constructor Details

VideoSource

protected VideoSource(int handle)

Method Details

getKindFromInt

public static VideoSource.Kind getKindFromInt(int kind)

Convert from the numerical representation of kind to an enum type.

Parameters:

kind - The numerical representation of kind

Returns:

The kind

close

public void close()

Specified by:

close in interface AutoCloseable

isValid

public boolean isValid()

getHandle

public int getHandle()

equals

public boolean equals(Object other)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

getKind

public VideoSource.Kind getKind()

Get the kind of the source.

Returns:

The kind of the source.

getName

public String getName()

Get the name of the source. The name is an arbitrary identifier provided when the source is created, and should be unique.

Returns:

The name of the source.

getDescription

public String getDescription()

Get the source description. This is source-kind specific.

Returns:

The source description.

getLastFrameTime

public long getLastFrameTime()

Get the last time a frame was captured.

Returns:

Time in 1 us increments.

setConnectionStrategy

public void setConnectionStrategy(VideoSource.ConnectionStrategy strategy)

Sets the connection strategy. By default, the source will automatically connect or disconnect based on whether any sinks are connected.

This function is non-blocking; look for either a connection open or close event or call isConnected() to determine the connection state.

Parameters:

strategy - connection strategy (auto, keep open, or force close)

isConnected

public boolean isConnected()

Returns true if the source currently connected to whatever is providing the images.

Returns:

True if the source currently connected to whatever is providing the images.

isEnabled

public boolean isEnabled()

Gets source enable status. This is determined with a combination of connection strategy and the number of sinks connected.

Returns:

True if enabled, false otherwise.

getProperty

public VideoProperty getProperty(String name)

Get a property.

Parameters:

name - Property name

Returns:

Property contents (of kind Property::kNone if no property with the given name exists)

enumerateProperties

public VideoProperty[] enumerateProperties()

Enumerate all properties of this source.

Returns:

Array of video properties.

getVideoMode

public VideoMode getVideoMode()

Get the current video mode.

Returns:

The current video mode.

setVideoMode

public boolean setVideoMode(VideoMode mode)

Set the video mode.

Parameters:

mode - Video mode

Returns:

True if set successfully.

setVideoMode

public boolean setVideoMode(VideoMode.PixelFormat pixelFormat, int width, int height, int fps)

Set the video mode.

Parameters:

pixelFormat - desired pixel format

width - desired width

height - desired height

fps - desired FPS

Returns:

True if set successfully

setPixelFormat

public boolean setPixelFormat(VideoMode.PixelFormat pixelFormat)

Set the pixel format.

Parameters:

pixelFormat - desired pixel format

Returns:

True if set successfully

setResolution

public boolean setResolution(int width, int height)

Set the resolution.

Parameters:

width - desired width

height - desired height

Returns:

True if set successfully

setFPS

public boolean setFPS(int fps)

Set the frames per second (FPS).

Parameters:

fps - desired FPS

Returns:

True if set successfully

setConfigJson

public boolean setConfigJson(String config)

Set video mode and properties from a JSON configuration string.

The format of the JSON input is:

 {
     "pixel format": "MJPEG", "YUYV", etc
     "width": video mode width
     "height": video mode height
     "fps": video mode fps
     "brightness": percentage brightness
     "white balance": "auto", "hold", or value
     "exposure": "auto", "hold", or value
     "properties": [
         {
             "name": property name
             "value": property value
         }
     ]
 }
 

Parameters:

config - configuration

Returns:

True if set successfully

getConfigJson

public String getConfigJson()

Get a JSON configuration string.

Returns:

JSON configuration string

getActualFPS

public double getActualFPS()

Get the actual FPS.

CameraServerJNI#setTelemetryPeriod() must be called for this to be valid (throws VisionException if telemetry is not enabled).

Returns:

Actual FPS averaged over the telemetry period.

getActualDataRate

public double getActualDataRate()

Get the data rate (in bytes per second).

CameraServerJNI#setTelemetryPeriod() must be called for this to be valid (throws VisionException if telemetry is not enabled).

Returns:

Data rate averaged over the telemetry period.

enumerateVideoModes

public VideoMode[] enumerateVideoModes()

Enumerate all known video modes for this source.

Returns:

Vector of video modes.

enumerateSinks

public VideoSink[] enumerateSinks()

Enumerate all sinks connected to this source.

Returns:

Vector of sinks.

enumerateSources

public static VideoSource[] enumerateSources()

Enumerate all existing sources.

Returns:

Vector of sources.