alexaClientSDK::mediaPlayer::BaseStreamSource Class Reference

#include <BaseStreamSource.h>

Inheritance diagram for alexaClientSDK::mediaPlayer::BaseStreamSource:

Collaboration diagram for alexaClientSDK::mediaPlayer::BaseStreamSource:

Public Member Functions
	BaseStreamSource (PipelineInterface *pipeline, const std::string &className)
	~BaseStreamSource () override
SourceInterface Functions
bool	hasAdditionalData () override
bool	handleEndOfStream () override
void	preprocess () override
void	addObserver (std::shared_ptr< SourceObserverInterface > observer) override
void	removeObserver (std::shared_ptr< SourceObserverInterface > observer) override
Public Member Functions inherited from alexaClientSDK::mediaPlayer::SourceInterface
	SourceInterface (const std::string &className)
virtual	~SourceInterface ()=default
virtual bool	isPlaybackRemote () const =0
Public Member Functions inherited from alexaClientSDK::avsCommon::utils::RequiresShutdown
	RequiresShutdown (const std::string &name)
virtual	~RequiresShutdown ()
	Destructor. More...
const std::string &	name () const
void	shutdown ()
bool	isShutdown () const

Protected Member Functions
bool	init (const avsCommon::utils::AudioFormat *audioFormat=nullptr)
virtual bool	isOpen ()=0
virtual void	close ()=0
virtual gboolean	handleReadData ()=0
virtual gboolean	handleSeekData (guint64 offset)=0
GstAppSrc *	getAppSrc () const
void	signalEndOfData ()
void	installOnReadDataHandler ()
void	updateOnReadDataHandler ()
void	uninstallOnReadDataHandler ()
void	clearOnReadDataHandler ()
void	notifyObserversOnReadData ()
Protected Member Functions inherited from alexaClientSDK::avsCommon::utils::RequiresShutdown
virtual void	doShutdown ()=0

Constructor & Destructor Documentation

BaseStreamSource()

alexaClientSDK::mediaPlayer::BaseStreamSource::BaseStreamSource	(	PipelineInterface *	pipeline,
		const std::string &	className
	)

Constructor.

Parameters

pipeline	The PipelineInterface through which the source of the AudioPipeline may be set.
className	The name of the class to be passed to RequiresShutdown.

~BaseStreamSource()

alexaClientSDK::mediaPlayer::BaseStreamSource::~BaseStreamSource ( )

override

Member Function Documentation

addObserver()

void alexaClientSDK::mediaPlayer::BaseStreamSource::addObserver ( std::shared_ptr< SourceObserverInterface >  observer )

overridevirtual

Adds an observer to be notified of particular events which occur on this source.

Parameters

observer

The observer to add.

Implements alexaClientSDK::mediaPlayer::SourceInterface.

clearOnReadDataHandler()

void alexaClientSDK::mediaPlayer::BaseStreamSource::clearOnReadDataHandler ( )

protected

Clear out the tracking of the onReadData() handler callback. This is used when gstreamer is known to have uninstalled the handler on its own.

close()

virtual void alexaClientSDK::mediaPlayer::BaseStreamSource::close ( )

protectedpure virtual

Close the audio source.

getAppSrc()

GstAppSrc* alexaClientSDK::mediaPlayer::BaseStreamSource::getAppSrc ( ) const

protected

Get the AppSrc to which this instance should feed audio data.

Returns

The AppSrc to which this instance should feed audio data.

handleEndOfStream()

bool alexaClientSDK::mediaPlayer::BaseStreamSource::handleEndOfStream ( )

overridevirtual

Internally, a source may need additional processing after EOS is reached. This function will process that data.

Returns

A boolean indicating whether the process operation was successful.

Implements alexaClientSDK::mediaPlayer::SourceInterface.

handleReadData()

virtual gboolean alexaClientSDK::mediaPlayer::BaseStreamSource::handleReadData ( )

protectedpure virtual

Reads data from this instance and pushes it into appsrc element.

Returns

false if there is an error or end of data from this source, else true.

handleSeekData()

virtual gboolean alexaClientSDK::mediaPlayer::BaseStreamSource::handleSeekData ( guint64  offset )

protectedpure virtual

Seeks to the appropriate offset. Any data pushed after this should come from the new offset.

Returns

false if the seek failed, or true otherwise.

hasAdditionalData()

bool alexaClientSDK::mediaPlayer::BaseStreamSource::hasAdditionalData ( )

overridevirtual

Internally, a source may have additional data after processing an EOS. This function indicates whether there is additional data, and should be called after handleEndOfStream().

Returns

A boolean indicating whether the source has additional data to be played.

Implements alexaClientSDK::mediaPlayer::SourceInterface.

init()

bool alexaClientSDK::mediaPlayer::BaseStreamSource::init ( const avsCommon::utils::AudioFormat *  audioFormat = nullptr )

protected

Initializes a source. Creates all the necessary pipeline elements such that audio output from the final element should be decoded output that can be input to the converter of the AudioPipeline. Adding the elements to the pipeline of the AudioPipeline, linking the elements and setting up the callbacks for signals should be handled.

Parameters

audioFormat

The audioFormat to be used when playing raw PCM data.

Returns

true if the initialization was successful else false.

installOnReadDataHandler()

void alexaClientSDK::mediaPlayer::BaseStreamSource::installOnReadDataHandler ( )

protected

Install the onReadData() handler. If it is already installed, reset the retry count.

isOpen()

virtual bool alexaClientSDK::mediaPlayer::BaseStreamSource::isOpen ( )

protectedpure virtual

Return whether the audio source is still open.

Returns

whether the audio source is still open.

notifyObserversOnReadData()

void alexaClientSDK::mediaPlayer::BaseStreamSource::notifyObserversOnReadData ( )

protected

A utility function to notify the observers of this object when data has been read.

preprocess()

void alexaClientSDK::mediaPlayer::BaseStreamSource::preprocess ( )

overridevirtual

Perform preprocessing of the source. Must be called before reading from the source.

Implements alexaClientSDK::mediaPlayer::SourceInterface.

removeObserver()

void alexaClientSDK::mediaPlayer::BaseStreamSource::removeObserver ( std::shared_ptr< SourceObserverInterface >  observer )

overridevirtual

Removes an observer from being notified of particular events which occur on this source.

Parameters

observer

The observer to remove.

Implements alexaClientSDK::mediaPlayer::SourceInterface.

signalEndOfData()

void alexaClientSDK::mediaPlayer::BaseStreamSource::signalEndOfData ( )

protected

Signal gstreamer about the end of data from this instance.

uninstallOnReadDataHandler()

void alexaClientSDK::mediaPlayer::BaseStreamSource::uninstallOnReadDataHandler ( )

protected

Uninstall the onReadData() handler.

updateOnReadDataHandler()

void alexaClientSDK::mediaPlayer::BaseStreamSource::updateOnReadDataHandler ( )

protected

Update when to call onReadData() handler based upon the number of retries since data was last read.

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

• /workplace/avs-device-sdk/MediaPlayer/GStreamerMediaPlayer/include/MediaPlayer/BaseStreamSource.h