Package org.openni
Class VideoStream
- java.lang.Object
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- org.openni.VideoStream
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public class VideoStream extends java.lang.Object
TheVideoStream
object encapsulates a single video stream from a device. Once created, it is used to start data flow from the device, and to read individual frames of data. This is the central class used to obtain data in OpenNI. It provides the ability to manually read data in a polling loop, as well as providing events and a Listener class that can be used to implement event-driven data acquisition. Aside from the video data frames themselves, the class offers a number of functions used for obtaining information about aVideoStream
. Field of view, available video modes, and minimum and maximum valid pixel values can all be obtained. In addition to obtaining data, theVideoStream
object is used to set all configuration properties that apply to a specific stream (rather than to an entire device). In particular, it is used to control cropping, mirroring, and video modes. A valid, initialized device that provides the desired stream type is required to create a stream. Several video streams can be created to stream data from the same sensor. This is useful if several components of an application need to read frames separately. While some device might allow different streams from the same sensor to have different configurations, most devices will have a single configuration for the sensor, shared by all streams.
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Nested Class Summary
Nested Classes Modifier and Type Class Description class
VideoStream.CameraSettings
TheVideoStream.CameraSettings
object encapsulates camera setting for a single device.static interface
VideoStream.NewFrameListener
The VideoStream::NewFrameListener interface is provided to allow the implementation of event driven frame reading.
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description void
addNewFrameListener(VideoStream.NewFrameListener streamListener)
Adds a new Listener to receive this VideoStream onNewFrame event.static VideoStream
create(Device device, SensorType sensorType)
Creates a stream of frames from a specific sensor type of a specific device.void
destroy()
Destroy this stream.VideoStream.CameraSettings
getCameraSettings()
Gets an object through which several camera settings can be configured.CropArea
getCropping()
Obtains the current cropping settings for this stream.long
getHandle()
This function return stream handle.float
getHorizontalFieldOfView()
Gets the horizontal field of view of frames received from this stream.int
getMaxPixelValue()
Provides the maximum possible value for pixels obtained by this stream.int
getMinPixelValue()
Provides the smallest possible value for pixels obtains by this VideoStream.boolean
getMirroringEnabled()
Check whether mirroring is currently turned on for this stream.SensorInfo
getSensorInfo()
Provides theSensorInfo
object associated with the sensor that is producing thisVideoStream
.SensorType
getSensorType()
Gets the sensor type for this stream.float
getVerticalFieldOfView()
Gets the vertical field of view of frames received from this stream.VideoMode
getVideoMode()
Get the current video mode information for this video stream.boolean
isCroppingSupported()
Checks whether this stream supports cropping.VideoFrameRef
readFrame()
Read the next frame from this video stream, delivered as aVideoFrameRef
.void
removeNewFrameListener(VideoStream.NewFrameListener streamListener)
Removes a Listener from this video stream list.void
resetCropping()
Disables cropping.void
setCropping(CropArea cropping)
Changes the cropping settings for this stream.void
setMirroringEnabled(boolean isEnabled)
Enable or disable mirroring for this stream.void
setVideoMode(VideoMode videoMode)
Changes the current video mode of this stream.void
start()
Starts data generation from this video stream.void
stop()
Stops data generation from this video stream.
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Method Detail
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create
public static VideoStream create(Device device, SensorType sensorType)
Creates a stream of frames from a specific sensor type of a specific device. You must supply a reference to a Device that supplies the sensor type requested. You can useDevice.hasSensor(SensorType)
to check whether a given sensor is available on your target device before calling create().- Parameters:
device
- A reference to theDevice
you want to create the stream on.sensorType
- The type of sensor the stream should produce data from.
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destroy
public void destroy()
Destroy this stream. This function is currently called automatically by the destructor, but it is considered a best practice for applications to manually call this function on anyVideoStream
that they call create() for.
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getSensorInfo
public final SensorInfo getSensorInfo()
Provides theSensorInfo
object associated with the sensor that is producing thisVideoStream
.SensorInfo
is useful primarily as a means of learning which video modes are valid for this VideoStream.- Returns:
- SensorInfo object associated with the sensor providing this stream.
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start
public void start()
Starts data generation from this video stream.
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stop
public void stop()
Stops data generation from this video stream.
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readFrame
public VideoFrameRef readFrame()
Read the next frame from this video stream, delivered as aVideoFrameRef
. This is the primary method for manually obtaining frames of video data. If no new frame is available, the call will block until one is available. To avoid blocking, useVideoStream.NewFrameListener
to implement an event driven architecture. Another alternative is to useOpenNI.waitForAnyStream(java.util.List, int)
to wait for new frames from several streams- Returns:
- VideoFrameRef object which hold the data of the new frame.
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addNewFrameListener
public void addNewFrameListener(VideoStream.NewFrameListener streamListener)
Adds a new Listener to receive this VideoStream onNewFrame event. SeeVideoStream.NewFrameListener
for more information on implementing an event driven frame reading architecture.- Parameters:
streamListener
- Object which implementsVideoStream.NewFrameListener
that will respond to this event.
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removeNewFrameListener
public void removeNewFrameListener(VideoStream.NewFrameListener streamListener)
Removes a Listener from this video stream list. The listener removed will no longer receive new frame events from this stream.- Parameters:
streamListener
- Object of the listener to be removed.
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getHandle
public long getHandle()
This function return stream handle.- Returns:
- OpenNI stream handle.
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getCameraSettings
public VideoStream.CameraSettings getCameraSettings()
Gets an object through which several camera settings can be configured.- Returns:
- null if the stream doesn't support camera settings.
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getVideoMode
public final VideoMode getVideoMode()
Get the current video mode information for this video stream. This includes its resolution, fps and stream format.- Returns:
- Current video mode information for this video stream.
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setVideoMode
public void setVideoMode(VideoMode videoMode)
Changes the current video mode of this stream. Recommended practice is to useDevice.getSensorInfo(SensorType)
, and thenSensorInfo.getSupportedVideoModes()
to obtain a list of valid video mode settings for this stream. Then, pass a validVideoMode
to setVideoMode(VideoMode) to ensure correct operation.- Parameters:
videoMode
- Desired new video mode for this stream. returns Status code indicating success or failure of this operation.
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getMaxPixelValue
public int getMaxPixelValue()
Provides the maximum possible value for pixels obtained by this stream. This is most useful for getting the maximum possible value of depth streams.- Returns:
- Maximum possible pixel value.
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getMinPixelValue
public int getMinPixelValue()
Provides the smallest possible value for pixels obtains by this VideoStream. This is most useful for getting the minimum possible value that will be reported by a depth stream.- Returns:
- Minimum possible pixel value that can come from this stream.
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isCroppingSupported
public boolean isCroppingSupported()
Checks whether this stream supports cropping.- Returns:
- true if the stream supports cropping, false if it does not.
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getCropping
public CropArea getCropping()
Obtains the current cropping settings for this stream.- Returns:
- CropArea CropArea object which encapsulated cropping info.
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setCropping
public void setCropping(CropArea cropping)
Changes the cropping settings for this stream. You can use theisCroppingSupported()
function to make sure cropping is supported before calling this function.- Parameters:
cropping
- CropArea object which set corresponding cropping information.
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resetCropping
public void resetCropping()
Disables cropping.
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getMirroringEnabled
public boolean getMirroringEnabled()
Check whether mirroring is currently turned on for this stream.- Returns:
- true if mirroring is currently enabled, false otherwise.
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setMirroringEnabled
public void setMirroringEnabled(boolean isEnabled)
Enable or disable mirroring for this stream.- Parameters:
isEnabled
- true to enable mirroring, false to disable it.
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getHorizontalFieldOfView
public float getHorizontalFieldOfView()
Gets the horizontal field of view of frames received from this stream.- Returns:
- Horizontal field of view, in radians.
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getVerticalFieldOfView
public float getVerticalFieldOfView()
Gets the vertical field of view of frames received from this stream.- Returns:
- Vertical field of view, in radians.
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getSensorType
public SensorType getSensorType()
Gets the sensor type for this stream.- Returns:
- sensor type.
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