xn::Player Class ReferenceProduction Nodes Functionality

#include <XnCppWrapper.h>

Inheritance diagram for xn::Player:

[legend]

List of all members.

Public Member Functions
	Player (XnNodeHandle hNode=NULL)
	Player (const NodeWrapper &other)
XnStatus	Create (Context &context, const XnChar *strFormatName)
XnStatus	SetRepeat (XnBool bRepeat)
XnStatus	SetSource (XnRecordMedium sourceType, const XnChar *strSource)
XnStatus	GetSource (XnRecordMedium &sourceType, XnChar *strSource, XnUInt32 nBufSize) const
XnStatus	ReadNext ()
XnStatus	SeekToTimeStamp (XnInt64 nTimeOffset, XnPlayerSeekOrigin origin)
XnStatus	SeekToFrame (const XnChar *strNodeName, XnInt32 nFrameOffset, XnPlayerSeekOrigin origin)
XnStatus	TellTimestamp (XnUInt64 &nTimestamp) const
XnStatus	TellFrame (const XnChar *strNodeName, XnUInt32 &nFrame) const
XnStatus	GetNumFrames (const XnChar *strNodeName, XnUInt32 &nFrames) const
const XnChar *	GetSupportedFormat () const
XnStatus	EnumerateNodes (NodeInfoList &list) const
XnBool	IsEOF () const
XnStatus	RegisterToEndOfFileReached (StateChangedHandler handler, void *pCookie, XnCallbackHandle &hCallback)
void	UnregisterFromEndOfFileReached (XnCallbackHandle hCallback)
XnStatus	SetPlaybackSpeed (XnDouble dSpeed)
XnDouble	GetPlaybackSpeed () const

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Detailed Description

Purpose: The Player class is used for creating and managing a Player node. This node plays a saved recording of an OpenNI data generation session.

Remarks:

To play a file recording, use the xn::Context::OpenFileRecording() function. OpenNI will open the file, create a mock node for each node in the file, and populate it with the recorded configuration.

An application may take the nodes it needs by calling the xn::Context::FindExistingNode() method, and use them normally.

Note:

Nodes created by the player are locked, and cannot be changed, as the configuration must remain according to the recorded configuration.

Applications that initialize OpenNI using an XML file can easily replace their input. This means that instead of reading from a physical device, which generates data in real-time, they read from a recording by replacing the nodes in the XML file with a recording element (see Xml Scripts).

Note:

It is not the Player node itself that is generating data. (Accordingly, the Player node does not provide a GetData() method.) The Player node reads data from the file, and "pushes" it into the mock nodes.

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Constructor & Destructor Documentation

xn::Player::Player

(

XnNodeHandle

hNode = NULL

)

[inline]

Ctor

Parameters:

[in]

hNode

Player node handle

xn::Player::Player

(

const NodeWrapper &

other

)

[inline]

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Member Function Documentation

XnStatus xn::Player::Create	(	Context &	context,
		const XnChar *	strFormatName
	)		[inline]

Creates a player node.

Remarks

See Concepts: the Create() Method for a detailed description about the operation of this method.

XnStatus xn::Player::EnumerateNodes

(

NodeInfoList &

list

)

const [inline]

Retrieves a list of the nodes played by a player.

For full details and usage, see xnEnumeratePlayerNodes

XnStatus xn::Player::GetNumFrames	(	const XnChar *	strNodeName,
		XnUInt32 &	nFrames
	)		const [inline]

Gets the total number of frames a specific node has in the recording.

Parameters:

[in]	strNodeName	Name of the node for which to retrieve the number of frames.
[out]	nFrames	Retrieved number of frames.

XnDouble xn::Player::GetPlaybackSpeed

(

)

const [inline]

Gets the playback speed.

Returns:

Speed ratio, or -1.0 if this node is not a player.

XnStatus xn::Player::GetSource	(	XnRecordMedium &	sourceType,
		XnChar *	strSource,
		XnUInt32	nBufSize
	)		const [inline]

Gets the player's source, that is, the type and name of the medium that the recording is played back from.

Parameters:

[out]	sourceType	Player's source type.
[in]	strSource	Player's source.
[in]	nBufSize	Size of the buffer specified by strSource.

const XnChar* xn::Player::GetSupportedFormat

(

)

const [inline]

Gets the name of the format supported by a player.

For full details and usage, see xnGetPlayerSupportedFormat

XnBool xn::Player::IsEOF

(

)

const [inline]

Returns whether the player is at the end-of-file marker.

Remarks

When Repeat mode is on, this function never returns TRUE. However, the 'End of File Reached' event will be raised during rewind.

XnStatus xn::Player::ReadNext

(

)

[inline]

Reads the next data element from the player.

For full details and usage, see xnPlayerReadNext

XnStatus xn::Player::RegisterToEndOfFileReached	(	StateChangedHandler	handler,
		void *	pCookie,
		XnCallbackHandle &	hCallback
	)		[inline]

Registers an event handler for the 'End-Of-File Reached' event.

Parameters:

[in]	handler	Callback function to be invoked when the event is raised.
[in]	pCookie	User's cookie, to be delivered to the callback.
[out]	hCallback	Handle to the callback to be used for unregistering it.

For full details and usage of the parameters, see Registering to Events.

XnStatus xn::Player::SeekToFrame	(	const XnChar *	strNodeName,
		XnInt32	nFrameOffset,
		XnPlayerSeekOrigin	origin
	)		[inline]

Moves the player to a specific frame of a specific played node, e.g., an ImageGenerator node, so that playing will continue from that frame onwards.

Parameters:

[in]	strNodeName	Name of the node.
[in]	nFrameOffset	Number of frames to move, relative to the specified origin. See remarks below.
[in]	origin	Origin to seek from. See remarks below.

The meaning of the nFrameOffset parameter changes according to the origin parameter:

XN_PLAYER_SEEK_SET: nFrameOffset specifies the total number of frames since the beginning of the node's recording. This must be a positive value.

XN_PLAYER_SEEK_CUR: nFrameOffset specifies the number of frames to move, relative to the current frame of the specified node. A positive value means to move forward, and a negative value means to move backwards.

XN_PLAYER_SEEK_END: nFrameOffset specifies the number of frames to move, relative to the end of the node's recording. This must be a negative value.

You can get different results using this function for different values of strNodeName, because the frame numbers of different nodes are not necessarily in sync.

XnStatus xn::Player::SeekToTimeStamp	(	XnInt64	nTimeOffset,
		XnPlayerSeekOrigin	origin
	)		[inline]

Moves the player to a specific time, so that playback will continue from that point onwards.

Parameters:

[in]	nTimeOffset	Offset to move, relative to the specified origin. Units in microseconds. See the remark below.
[in]	origin	Origin to seek from. See the remarks below.

The meaning of the nTimeOffset parameter changes according to the origin parameter:

XN_PLAYER_SEEK_SET: nTimeOffset specifies the total time passed since the beginning of the recording. This must be a positive value.

XN_PLAYER_SEEK_CUR: nTimeOffset specifies a period of time to move, relative to the current player position. A positive value means to move forward, and a negative value means to move backwards.

XN_PLAYER_SEEK_END: nTimeOffset specifies a period of time to move, relative to the end of the recording. This must be a negative value.

Remarks

For the built-in ONI player, this function is not currently supported and always returns XN_STATUS_NOT_IMPLEMENTED.

XnStatus xn::Player::SetPlaybackSpeed

(

XnDouble

dSpeed

)

[inline]

Sets the player's playback speed, as a ratio of the rate that the recording was made at.

Parameters:

[in]

dSpeed

The speed ratio.

Values:

dSpeed = 1.0 - Player will try to output frames at the same rate they were recorded (according to their timestamps).

dSpeed > 1.0 - Fast-forward

0 < dSpeed < 1.0 - Slow-motion.

dSpeed = XN_PLAYBACK_SPEED_FASTEST (0.0) - There will be no delay, and frames will be returned immediately on demand.

XnStatus xn::Player::SetRepeat

(

XnBool

bRepeat

)

[inline]

Specifies whether the player will automatically rewind to the beginning of the recording after reaching the end of the recording.

Parameters:

[in]

bRepeat

Determines whether the player will repeat or not.

If bRepeat is set to TRUE, the player will automatically rewind when reaching the end.

If bRepeat is set to FALSE, the player will stop playing when reaching the end, and will raise the 'End-Of-File Reached' event. In this state, IsEOF() returns TRUE, and calls to ReadNext() will fail.

XnStatus xn::Player::SetSource	(	XnRecordMedium	sourceType,
		const XnChar *	strSource
	)		[inline]

Sets the source for the player, i.e. where the played events will come from.

For full details and usage, see xnSetPlayerSource

XnStatus xn::Player::TellFrame	(	const XnChar *	strNodeName,
		XnUInt32 &	nFrame
	)		const [inline]

Gets the current frame number of a specific node played by a player, i.e., the number of frames passed since the beginning of the recording.

Parameters:

[in]	strNodeName	Name of the node.
[out]	nFrame	Retrieved frame number.

Remarks

Different nodes that belong to the player can have different frame numbers, because the nodes are not necessarily in synchronization.

XnStatus xn::Player::TellTimestamp

(

XnUInt64 &

nTimestamp

)

const [inline]

Gets the current time of a player, i.e., the time passed since the beginning of the recording.

Parameters:

[out]

nTimestamp

Retrieved timestamp. Units are in microseconds.

void xn::Player::UnregisterFromEndOfFileReached

(

XnCallbackHandle

hCallback

)

[inline]

Unregisters the event handler for the 'End-Of-File Reached' event.

Parameters:

[in]

hCallback

Handle received from registration.

For full details and usage of the parameter, see Unregistering from Events .

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

• XnCppWrapper.h