org.jitsi.impl.neomedia.device

Class DeviceSystem

java.lang.Object

org.jitsi.utils.event.PropertyChangeNotifier

org.jitsi.impl.neomedia.device.DeviceSystem

Direct Known Subclasses:

AudioSystem, DirectShowSystem, ImgStreamingSystem, QuickTimeSystem, Video4Linux2System

public abstract class DeviceSystem
extends org.jitsi.utils.event.PropertyChangeNotifier

Represents the base of a supported device system/backend such as DirectShow, PortAudio, PulseAudio, QuickTime, video4linux2. A DeviceSystem is initialized at a certain time (usually, during the initialization of the MediaService implementation which is going to use it) and it registers with FMJ the CaptureDevices it will provide. In addition to providing the devices for the purposes of capture, a DeviceSystem also provides the devices on which playback is to be performed i.e. it acts as a Renderer factory via its createRenderer() method.

Author:

Lyubomir Marinov

Field Summary

Fields

Modifier and Type	Field and Description
static int	FEATURE_REINITIALIZE The constant/flag (to be) returned by getFeatures() in order to indicate that the respective DeviceSystem supports invoking its initialize() more than once.
static String	LOCATOR_PROTOCOL_ANDROIDCAMERA
static String	LOCATOR_PROTOCOL_CIVIL
static String	LOCATOR_PROTOCOL_DIRECTSHOW
static String	LOCATOR_PROTOCOL_IMGSTREAMING
static String	LOCATOR_PROTOCOL_MEDIARECORDER
static String	LOCATOR_PROTOCOL_QUICKTIME
static String	LOCATOR_PROTOCOL_VIDEO4LINUX2
static String	PROP_DEVICES

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	DeviceSystem(org.jitsi.utils.MediaType mediaType, String locatorProtocol)
protected	DeviceSystem(org.jitsi.utils.MediaType mediaType, String locatorProtocol, int features)

Method Summary

Modifier and Type	Method and Description
javax.media.Renderer	createRenderer() Initializes a new Renderer instance which is to perform playback on a device contributed by this system.
protected abstract void	doInitialize() Invoked by initialize() to perform the very logic of the initialization of this DeviceSystem.
protected static List<javax.media.CaptureDeviceInfo>	filterDeviceListByLocatorProtocol(List<javax.media.CaptureDeviceInfo> deviceList, String locatorProtocol) Returns a List of CaptureDeviceInfos which are elements of a specific List of CaptureDeviceInfos and have a specific MediaLocator protocol.
static DeviceSystem[]	getDeviceSystems(org.jitsi.utils.MediaType mediaType)
int	getFeatures() Gets the flags indicating the optional features supported by this DeviceSystem.
javax.media.Format	getFormat() Returns the format depending on the media type: AudioFormat for AUDIO, VideoFormat for VIDEO.
String	getLocatorProtocol() Gets the protocol of the MediaLocators of the CaptureDeviceInfos (to be) registered (with FMJ) by this DeviceSystem.
org.jitsi.utils.MediaType	getMediaType()
protected String	getRendererClassName() Gets the name of the class which implements the Renderer interface to render media on a playback or notification device associated with this DeviceSystem.
protected void	initialize() Initializes this DeviceSystem i.e.
static void	initializeDeviceSystems() Initializes the DeviceSystem instances which are to represent the supported device systems/backends such as DirectShow, PortAudio, PulseAudio, QuickTime, video4linux2.
static void	initializeDeviceSystems(org.jitsi.utils.MediaType mediaType) Initializes the DeviceSystem instances which are to represent the supported device systems/backends which are to capable of capturing and playing back media of a specific type such as audio or video.
protected void	postInitialize() Invoked as part of the execution of initialize() after the execution of doInitialize() regardless of whether the latter completed successfully.
protected void	preInitialize() Invoked as part of the execution of initialize() before the execution of doInitialize().
String	toString() Returns a human-readable representation of this DeviceSystem.

Methods inherited from class org.jitsi.utils.event.PropertyChangeNotifier

addPropertyChangeListener, firePropertyChange, getPropertyChangeSource, removePropertyChangeListener

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

FEATURE_REINITIALIZE

public static final int FEATURE_REINITIALIZE

The constant/flag (to be) returned by getFeatures() in order to indicate that the respective DeviceSystem supports invoking its initialize() more than once.

See Also:

Constant Field Values

LOCATOR_PROTOCOL_ANDROIDCAMERA

public static final String LOCATOR_PROTOCOL_ANDROIDCAMERA

See Also:

Constant Field Values

LOCATOR_PROTOCOL_CIVIL

public static final String LOCATOR_PROTOCOL_CIVIL

See Also:

Constant Field Values

LOCATOR_PROTOCOL_DIRECTSHOW

public static final String LOCATOR_PROTOCOL_DIRECTSHOW

See Also:

Constant Field Values

LOCATOR_PROTOCOL_IMGSTREAMING

public static final String LOCATOR_PROTOCOL_IMGSTREAMING

See Also:

Constant Field Values

LOCATOR_PROTOCOL_MEDIARECORDER

public static final String LOCATOR_PROTOCOL_MEDIARECORDER

See Also:

Constant Field Values

LOCATOR_PROTOCOL_QUICKTIME

public static final String LOCATOR_PROTOCOL_QUICKTIME

See Also:

Constant Field Values

LOCATOR_PROTOCOL_VIDEO4LINUX2

public static final String LOCATOR_PROTOCOL_VIDEO4LINUX2

See Also:

Constant Field Values

PROP_DEVICES

public static final String PROP_DEVICES

See Also:

Constant Field Values

Constructor Detail

DeviceSystem

protected DeviceSystem(org.jitsi.utils.MediaType mediaType,
                       String locatorProtocol)
                throws Exception

Throws:

Exception

DeviceSystem

protected DeviceSystem(org.jitsi.utils.MediaType mediaType,
                       String locatorProtocol,
                       int features)
                throws Exception

Throws:

Exception

Method Detail

filterDeviceListByLocatorProtocol

protected static List<javax.media.CaptureDeviceInfo> filterDeviceListByLocatorProtocol(List<javax.media.CaptureDeviceInfo> deviceList,
                                                                                       String locatorProtocol)

Returns a List of CaptureDeviceInfos which are elements of a specific List of CaptureDeviceInfos and have a specific MediaLocator protocol.

Parameters:

deviceList - the List of CaptureDeviceInfo which are to be filtered based on the specified MediaLocator protocol

locatorProtocol - the protocol of the MediaLocators of the CaptureDeviceInfos which are to be returned

Returns:

a List of CaptureDeviceInfos which are elements of the specified deviceList and have the specified locatorProtocol

getDeviceSystems

public static DeviceSystem[] getDeviceSystems(org.jitsi.utils.MediaType mediaType)

initializeDeviceSystems

public static void initializeDeviceSystems()

Initializes the DeviceSystem instances which are to represent the supported device systems/backends such as DirectShow, PortAudio, PulseAudio, QuickTime, video4linux2. The method may be invoked multiple times. If a DeviceSystem has been initialized by a previous invocation of the method, its initialize() method will be called again as part of the subsequent invocation only if the DeviceSystem in question returns a set of flags from its getFeatures() method which contains the constant/flag FEATURE_REINITIALIZE.

initializeDeviceSystems

public static void initializeDeviceSystems(org.jitsi.utils.MediaType mediaType)

Initializes the DeviceSystem instances which are to represent the supported device systems/backends which are to capable of capturing and playing back media of a specific type such as audio or video.

Parameters:

mediaType - the MediaType of the DeviceSystems to be initialized

createRenderer

public javax.media.Renderer createRenderer()

Initializes a new Renderer instance which is to perform playback on a device contributed by this system.

Returns:

a new Renderer instance which is to perform playback on a device contributed by this system or null

doInitialize

protected abstract void doInitialize()
                              throws Exception

Invoked by initialize() to perform the very logic of the initialization of this DeviceSystem. This instance has been prepared for initialization by an earlier call to preInitialize() and the initialization will be completed with a subsequent call to postInitialize().

Throws:

Exception - if an error occurs during the initialization of this instance. The initialization of this instance will be completed with a subsequent call to postInitialize() regardless of any Exception thrown by doInitialize().

getFeatures

public final int getFeatures()

Gets the flags indicating the optional features supported by this DeviceSystem.

Returns:

the flags indicating the optional features supported by this DeviceSystem. The possible flags are among the FEATURE_XXX constants defined by the DeviceSystem class and its extenders.

getFormat

public javax.media.Format getFormat()

Returns the format depending on the media type: AudioFormat for AUDIO, VideoFormat for VIDEO. Otherwise, returns null.

Returns:

The format depending on the media type: AudioFormat for AUDIO, VideoFormat for VIDEO. Otherwise, returns null.

getLocatorProtocol

public final String getLocatorProtocol()

Gets the protocol of the MediaLocators of the CaptureDeviceInfos (to be) registered (with FMJ) by this DeviceSystem. The protocol is a unique identifier of a DeviceSystem.

Returns:

the protocol of the MediaLocators of the CaptureDeviceInfos (to be) registered (with FMJ) by this DeviceSystem

getMediaType

public final org.jitsi.utils.MediaType getMediaType()

getRendererClassName

protected String getRendererClassName()

Gets the name of the class which implements the Renderer interface to render media on a playback or notification device associated with this DeviceSystem.

Returns:

the name of the class which implements the Renderer interface to render media on a playback or notification device associated with this DeviceSystem or null if no Renderer instance is to be created by the DeviceSystem implementation or createRenderer(boolean) is overridden.

initialize

protected final void initialize()
                         throws Exception

Initializes this DeviceSystem i.e. represents the native/system devices in the terms of the application so that they may be utilized. For example, the capture devices are represented as CaptureDeviceInfo instances registered with FMJ.

Note: The method is synchronized on this instance in order to guarantee that the whole initialization procedure (which includes doInitialize()) executes once at any given time.

Throws:

Exception - if an error occurs during the initialization of this DeviceSystem

postInitialize

protected void postInitialize()
                       throws Exception

Invoked as part of the execution of initialize() after the execution of doInitialize() regardless of whether the latter completed successfully. The implementation of DeviceSystem fires a new PropertyChangeEvent to notify that the value of the property PROP_DEVICES of this instance may have changed i.e. that the list of devices detected by this instance may have changed.

Throws:

Exception

preInitialize

protected void preInitialize()
                      throws Exception

Invoked as part of the execution of initialize() before the execution of doInitialize(). The implementation of DeviceSystem removes from FMJ's CaptureDeviceManager the CaptureDeviceInfos whose MediaLocator has the same protocol as getLocatorProtocol() of this instance.

Throws:

Exception

toString

public String toString()

Returns a human-readable representation of this DeviceSystem. The implementation of DeviceSystem returns the protocol of the MediaLocators of the CaptureDeviceInfos (to be) registered by this DeviceSystem.

Overrides:

toString in class Object

Returns:

a String which represents this DeviceSystem in a human-readable form