CMMFAudioInput Class Reference

#include <mmf/server/mmfaudioinput.h>

class CMMFAudioInput : public CBase, public MMMFAudioInput, public MDevSoundObserver, public CBase, public MMMFAudioInput, public MDevSoundObserver

Inherits from

CMMFAudioInput

Public Attributes
TRequestStatus	iBufferStatus

Public Member Functions
virtual	~CMMFAudioInput()
virtual void	BufferEmptiedL(CMMFBuffer *)
virtual TInt	BytesPlayed()
virtual TBool	CanCreateSourceBuffer()
void	ConstructL()
virtual CMMFBuffer *	CreateSourceBufferL(TMediaId)
virtual CMMFBuffer *	CreateSourceBufferL(TMediaId, CMMFBuffer &)
virtual CMMFBuffer *	CreateSourceBufferL(TMediaId, TBool &)
virtual CMMFBuffer *	CreateSourceBufferL(TMediaId, CMMFBuffer &, TBool &)
virtual TFourCC	DataType()
virtual void	FillBufferL(CMMFBuffer , MDataSink , TMediaId)
virtual void	HWFillBufferL(CMMFBuffer , MDataSink )
void	LoadL()
virtual void	NegotiateSourceL(MDataSink &)
MDataSource *	NewSourceL()
virtual void	SetDataTypeL(TFourCC)
virtual TInt	SetSourceDataTypeCode(TFourCC, TMediaId)
virtual void	SetSourcePrioritySettings(const TMMFPrioritySettings &)
virtual CMMFDevSound &	SoundDevice()
virtual TFourCC	SourceDataTypeCode(TMediaId)
virtual void	SourcePauseL()
virtual void	SourcePlayL()
virtual void	SourcePrimeL()
virtual void	SourceStopL()
virtual void	SourceThreadLogoff()
virtual TInt	SourceThreadLogon(MAsyncEventHandler &)

Protected Member Functions
virtual void	ConstructSourceL(const TDesC8 &)

Inherited Functions
	CBase::CBase()
	CBase::Delete(CBase *)
	CBase::Extension_(TUint,TAny &,TAny )
	CBase::operator new(TUint)
	CBase::operator new(TUint,TAny *)
	CBase::operator new(TUint,TLeave)
	CBase::operator new(TUint,TLeave,TUint)
	CBase::operator new(TUint,TUint)
	CBase::~CBase()
	MDataSource::DataSourceType()const
	MDataSource::MDataSource(TUid)
	MDataSource::NewSourceL(TUid,const TDesC8 &)
	MDataSource::NewSourceLC(TUid,const TDesC8 &)
	MDataSource::SourceCustomCommand(TMMFMessage &)
	MDataSource::SourceSampleConvert()
	MDataSource::~MDataSource()
	MMMFAudioInput::MMMFAudioInput()
	MMMFAudioInput::NewAudioInputL(TUid,const TDesC8 &)

Detailed Description

Concrete data source to provide microphone support.

Intended to be used by controller plugin developers for source plugins. Uses CMMFDevSound to access hardware.

Member Attribute Documentation

iBufferStatus

TRequestStatus

iBufferStatus

Buffer completion status.

Constructor & Destructor Documentation

~CMMFAudioInput ( )

~CMMFAudioInput

(

)

[virtual]

Member Function Documentation

BufferEmptiedL ( CMMFBuffer * )

void

BufferEmptiedL

(

CMMFBuffer *

aBuffer

)

[virtual]

Reimplemented from MDataSource::BufferEmptiedL(CMMFBuffer *)

Function called by a data sink to pass back an emptied buffer to the source.

This is a pure virtual function that each derived class must implement. This method is used as the callback when the data source actively requests a consumer ie. a data sink to empty a buffer by calling the data sinks EmptyBufferL. When the data source gets this callback it knows that the buffer has been emptied and can be reused.

Parameters
aBuffer	The buffer that has been emptied by a data sink and is now available for reuse.

BytesPlayed ( )

TInt

BytesPlayed

(

)

[virtual]

Reimplemented from MMMFAudioInput::BytesPlayed()

Returns the number of bytes played.

Return Value: The number of bytes played. If 16-bit divide this number returned by 2 to get word length.

CanCreateSourceBuffer ( )

TBool

CanCreateSourceBuffer

(

)

[virtual]

Reimplemented from MDataSource::CanCreateSourceBuffer()

Deprecated

Function to indicate whether the data source can create a buffer.

This is a pure virtual function that each derived class must implement.

Return Value: A boolean indicating if the data source can create a buffer. ETrue if it can otherwise EFalse.

ConstructL ( )

void

ConstructL

(

)

ConstructSourceL ( const TDesC8 & )

void

ConstructSourceL

(

const TDesC8 &

aInitData

)

[protected, virtual]

Reimplemented from MDataSource::ConstructSourceL(const TDesC8 &)

Performs any source construction dependant on the source construction initialisation data aInitData.

This is a pure virtual function that a derrived data source must implement

Parameters
aInitData	The source specific initialisation data required for source construction.

CreateSourceBufferL ( TMediaId )

CMMFBuffer *

CreateSourceBufferL

(

TMediaId

aMediaId

)

[virtual]

CreateSourceBufferL ( TMediaId, CMMFBuffer & )

CMMFBuffer *	CreateSourceBufferL	(	TMediaId	aMediaId,
			CMMFBuffer &	aSinkBuffer
		)	[inline, virtual]

Intended for synchronous usage (returns buffer specific to a Media Type).

Parameters
aMediaId	The Media ID.
aSinkBuffer	Not Used.

Return Value: A pointer to the CMMFBuffer source buffer.

CreateSourceBufferL ( TMediaId, TBool & )

CMMFBuffer *	CreateSourceBufferL	(	TMediaId	aMediaId,
			TBool &	aReference
		)	[virtual]

Reimplemented from MDataSource::CreateSourceBufferL(TMediaId,TBool &)

Deprecated

Returns a buffer created by the data source

This is a pure virtual function that each derived class must implement.

Parameters
aMediaId	This identifies the type of media eg. audio or video and the stream ID. This parameter is required in cases where the source can supply data of more than one media type and/or multiple strams of data eg a multimedia file.
aReference	This must be written to by the method to indicate whether the created buffer is a 'reference' buffer. A 'reference' buffer is a buffer that is owned by the source and should be used in preference to the sink buffer provided the sink buffer is also not a reference buffer.

Return Value: A pointer to the created buffer.

CreateSourceBufferL ( TMediaId, CMMFBuffer &, TBool & )

CMMFBuffer *	CreateSourceBufferL	(	TMediaId	aMediaId,
			CMMFBuffer &	aSinkBuffer,
			TBool &	aReference
		)	[inline, virtual]

Reimplemented from MDataSource::CreateSourceBufferL(TMediaId,CMMFBuffer &,TBool &)

Creates a source buffer.

Intended for asynchronous usage (returns buffer specific to a Media Type).

Parameters
aMediaId	The Media ID.
aSinkBuffer	Not used.
aReference	A boolean indicating if MDataSource owns the buffer. If EFalse the the caller owns the buffer.

Return Value: The source buffer.

DataType ( )

TFourCC

DataType

(

)

const [virtual]

FillBufferL ( CMMFBuffer , MDataSink , TMediaId )

void	FillBufferL	(	CMMFBuffer *	aBuffer,
			MDataSink *	aConsumer,
			TMediaId	aMediaId
		)	[virtual]

Reimplemented from MDataSource::FillBufferL(CMMFBuffer *,MDataSink *,TMediaId)

Function called by a MDataSink to request the data source to fill aBuffer with data.

This is a pure virtual function that each derived class must implement. This method is used when a data source is passively waiting for requests from a consumer ie. a data sink to fill a buffer. The data source must call the BufferFilledL member on aConsumer when it has filled the buffer with data. The data source can either make this callback synchronously or asynchronously.

The format should read the frame number of the buffer via the buffer's CMMFBuffer::FrameNumber() function. From this, the format should be able to determine the actual position of the data on the data source. The technique here depends on the nature of the format. For a linear audio format, the position can be obtained by a simple calculation of the frame size, the header size and where appropriate the datatype.

For non-linear formats, either an index table of frame number and location will need to be created in the NewL() or some form of approximating algorithm will be required. Some formats have an index table as part of the format eg. AVI. If no random access is required then no index table is required, the format can keep track of the current read position and increment it on each access, and reset it if the frame number is reset to 0 or 1. Given that for non-linear ie. variable bit rate formats, the size of the data read may vary from frame to frame, then the format should either set the request size of the buffer for the required frame or call the source's ReadBufferL() (either CMMFClip::ReadBufferL(), CMMFDescriptor ::ReadBufferL() or CMMFFile::ReadBufferL()) function that takes the aLength parameter.

It is the responsibility of the format decode to determine the size and position of the source data for each frame. For linear audio formats, the format decode should fill the buffer up to its maximum length. For multimedia formats e.g. mp4, AVI etc, the format decode is effectively acting as a demultiplexor, and must obtain the appropriate data from the source depending on the aMediaId.

Parameters
aBuffer	The buffer that needs filling with data.
aConsumer	The data sink that consumes the data. The data source needs this to make the BufferFilledL callback on aConsumer when the data source has completed filling the aBuffer.
aMediaId	This identifies the type of media eg. audio or video and the stream ID. This parameter is required in cases where the source can supply data of more than one media type and/or multiple strams of data eg. a multimedia file.

HWFillBufferL ( CMMFBuffer , MDataSink )

void	HWFillBufferL	(	CMMFBuffer *	aBuffer,
			MDataSink *	aConsumer
		)	[virtual]

Reimplemented from MMMFAudioInput::HWFillBufferL(CMMFBuffer *,MDataSink *)

Deprecated

Gets audio from hardware device abstracted MMFDevsound (not used).

Parameters
aBuffer	The data to read in from a Hardware Device
aConsumer	The MDataSink consuming the data contained in aBuffer.

LoadL ( )

void

LoadL

(

)

NegotiateSourceL ( MDataSink & )

void

NegotiateSourceL

(

MDataSink &

aDataSink

)

[virtual]

Reimplemented from MDataSource::NegotiateSourceL(MDataSink &)

Function to allow the data source to negotiate with a data sink

This method is required in cases where the settings of data source are dependant on those of a data sink. This is a virtual function that a derrived data source can implement.

Parameters
aDataSink	The data sink whose settings can affect the data source.

NewSourceL ( )

MDataSource *

NewSourceL

(

)

[static]

SetDataTypeL ( TFourCC )

void

SetDataTypeL

(

TFourCC

aAudioType

)

[virtual]

SetSourceDataTypeCode ( TFourCC, TMediaId )

TInt	SetSourceDataTypeCode	(	TFourCC	aSourceFourCC,
			TMediaId	aMediaId
		)	[virtual]

Reimplemented from MDataSource::SetSourceDataTypeCode(TFourCC,TMediaId)

Sets the data type as a fourCC code for the data source.

This is a virtual function that each derived class can implement if the data source supports the ability to have its data type set.

Parameters
aSourceFourCC	This specifies the data type as a fourCC code to set the source to.
aMediaId	This identifies the type of media eg. audio or video and the stream ID. This parameter is required in cases where the source can supply data of more than one media type and/or multiple strams of data eg a multimedia file.

Return Value: KErrNone if successful, KErrNotSupported if the source does not support having it's data type set, otherwise a system wide error code.

SetSourcePrioritySettings ( const TMMFPrioritySettings & )

void

SetSourcePrioritySettings

(

const TMMFPrioritySettings &

aPrioritySettings

)

[virtual]

Reimplemented from MDataSource::SetSourcePrioritySettings(const TMMFPrioritySettings &)

Function to set the source priority settings.

This is a virtual function that a derrived data source can implement if a priority mechanism is required to arbitrate between multiple clients trying to access the same resource.

Parameters
aPrioritySettings	The source priority settings.

SoundDevice ( )

CMMFDevSound &

SoundDevice

(

)

[virtual]

Reimplemented from MMMFAudioInput::SoundDevice()

Returns the sound device.

Return Value: A reference to a CMMFDevSound objector. Accessor function exposing public CMMFDevsound methods.

SourceDataTypeCode ( TMediaId )

TFourCC

SourceDataTypeCode

(

TMediaId

aMediaId

)

[virtual]

Reimplemented from MDataSource::SourceDataTypeCode(TMediaId)

Returns the data type as a fourCC code of the data source.

This is a pure virtual function that each derrived class must implement.

Parameters
aMediaId	This identifies the type of media eg. audio or video and the stream ID. This parameter is required in cases where the source can supply data of more than one media type and/or multiple streams of data.

Return Value: The fourCC code identifying the source datatype for the specified aMediaId.

SourcePauseL ( )

void

SourcePauseL

(

)

[virtual]

Reimplemented from MDataSource::SourcePauseL()

Function to 'pause' the data source.

This is a virtual function that a derrived data source can implement if any data source specific action is required to 'pause'

SourcePlayL ( )

void

SourcePlayL

(

)

[virtual]

Reimplemented from MDataSource::SourcePlayL()

Function to 'play' the data source.

This is a virtual function that a derrived data source can implement if any data source specific action is required prior to 'playing' ie. the start of data transfer.

SourcePrimeL ( )

void

SourcePrimeL

(

)

[virtual]

Reimplemented from MDataSource::SourcePrimeL()

Function to 'prime' the data source.

This is a virtual function that a derrived data source can implement if any data source specific 'priming' is required.

SourceStopL ( )

void

SourceStopL

(

)

[virtual]

Reimplemented from MDataSource::SourceStopL()

Function to 'stop' the data source.

This is a virtual function that a derrived data source can implement if any data source specific action is required to 'stop'.

SourceThreadLogoff ( )

void

SourceThreadLogoff

(

)

[virtual]

Reimplemented from MDataSource::SourceThreadLogoff()

Function to 'logoff' the data source from the same thread that source supplies data in.

This method may be required as the thread that the data source is deleted in may not be the same thread that the data transfer took place in. Therefore any thread specific releasing of resources needs to be performed in the SourceThreadLogoff rather than in the destructor.

This is a virtual function that a derrived data source can implement if any thread specific releasing of resources is required.

SourceThreadLogon ( MAsyncEventHandler & )

TInt

SourceThreadLogon

(

MAsyncEventHandler &

aEventHandler

)

[virtual]

Reimplemented from MDataSource::SourceThreadLogon(MAsyncEventHandler &)

Function to 'logon' the data source to the same thread that source will be supplying data in.

This method may be required as the thread that the data source was created in is not always the same thread that the data transfer will take place in. Therefore any thread specific initialisation needs to be performed in the SourceThreadLogon rather than in the creation of the data source.

This is a virtual function that a derrived data source can implement if any thread specific initialisation is required and/or the data source can create any asynchronous events.

Parameters
aEventHandler	This is an MAsyncEventHandler to handle asynchronous events that occur during the transfer of multimedia data. The event handler must be in the same thread as the data transfer thread. Hence the reason it is passed in the SourceThreadLogon as opposed to say the constructor.

Return Value: An error code indicating if the function call was successful. KErrNone on success, otherwise another of the system-wide error codes.

CMMFAudioInput Class Reference

Inherits from

Detailed Description

Member Attribute Documentation

iBufferStatus

Constructor & Destructor Documentation

~CMMFAudioInput ( )

Member Function Documentation

BufferEmptiedL ( CMMFBuffer * )

BytesPlayed ( )

CanCreateSourceBuffer ( )

ConstructL ( )

ConstructSourceL ( const TDesC8 & )

CreateSourceBufferL ( TMediaId )

CreateSourceBufferL ( TMediaId, CMMFBuffer & )

CreateSourceBufferL ( TMediaId, TBool & )

CreateSourceBufferL ( TMediaId, CMMFBuffer &, TBool & )

DataType ( )

FillBufferL ( CMMFBuffer *, MDataSink *, TMediaId )

HWFillBufferL ( CMMFBuffer *, MDataSink * )

LoadL ( )

NegotiateSourceL ( MDataSink & )

NewSourceL ( )

SetDataTypeL ( TFourCC )

SetSourceDataTypeCode ( TFourCC, TMediaId )

SetSourcePrioritySettings ( const TMMFPrioritySettings & )

SoundDevice ( )

SourceDataTypeCode ( TMediaId )

SourcePauseL ( )

SourcePlayL ( )

SourcePrimeL ( )

SourceStopL ( )

SourceThreadLogoff ( )

SourceThreadLogon ( MAsyncEventHandler & )

FillBufferL ( CMMFBuffer , MDataSink , TMediaId )

HWFillBufferL ( CMMFBuffer , MDataSink )