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CMMFHwDevice Class Reference

class CMMFHwDevice : public CBase

ECom plugin class for a hardware device that decodes (plays) source data in a certain FourCC coding type to another FourCC coding type or encodes (records) data from a certain FourCC coding type to a another FourCC coding type.

The hardware device can be instantiated in 3 different ways:

1. NewL(const TFourCC& aSrcDatatype, const TFourCC& aDstDataType)

This instantiate a hardware device that can encode or decode the aSrcDatatype to a aDstDataType.

2. NewL(const TFourCC& aSrcDatatype, const TFourCC& aDstDataType, const TDesC& aPreferredSupplier)

This is similar to the above but is used where there may be multiple hardware devices that perform the same conversion. Third party developers may use their own hardware device implementations and can ensure the controller uses their implementation by setting the preferred supplier to themselves.

3. NewL(TUid aUid)

This is used to explicitly instantiate a hardware device where the UID is known.

4. NewL(TFileName aFileName)

This is used to create an instance of a HwDevice implementation by loading the library

CMMFHwDevice provides a generic interface that every Hardware Device that decodes and/or encodes has to implement. Based on parameters specified in Start, the device implementation will start decoding or encoding. The source and destination of the decoding/encoding operations should be set up before starting the task by sending THwDeviceInitParams to the Init() function.

Inherits from

CMMFHwDevice
- CBase

Public Member Functions
	~CMMFHwDevice()
TAny *	CustomInterface(TUid)
TInt	DeleteCodec()
TInt	Init(THwDeviceInitParams &)
CMMFHwDevice *	NewL(const TFourCC &, const TFourCC &)
CMMFHwDevice *	NewL(const TFourCC &, const TFourCC &, const TDesC &)
CMMFHwDevice *	NewL(TUid)
CMMFHwDevice *	NewL(TFileName)
TInt	Pause()
TInt	SetConfig(TTaskConfig &)
TInt	Start(TDeviceFunc, TDeviceFlow)
TInt	Stop()
TInt	StopAndDeleteCodec()
TInt	ThisHwBufferEmptied(CMMFBuffer &)
TInt	ThisHwBufferFilled(CMMFBuffer &)

Private Member Functions
void	SelectByPreference(RImplInfoPtrArray &, const TDesC &)

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()

Protected Attributes
MMMFHwDeviceObserver *	iHwDeviceObserver

Private Attributes
TUid	iDtor_ID_Key

Constructor & Destructor Documentation

~CMMFHwDevice()

~CMMFHwDevice

(

)

[inline, virtual]

Destructor.

The destructor is called by ECom framework allowing derived classes to clean up the implementation specific resources.

Destructor

Member Functions Documentation

CustomInterface(TUid)

TAny *

CustomInterface

(

TUid

aInterfaceId

)

[pure virtual]

Retrieves a custom interface to the device.

Parameters

TUid aInterfaceId

The interface UID, defined with the custom interface.

DeleteCodec()

TInt

DeleteCodec

(

)

[pure virtual]

Call this function to delete a codec.

This is used to allow resources to be freed when using a DSP or similar hardware.

Init(THwDeviceInitParams &)

TInt

Init

(

THwDeviceInitParams &

aDevInfo

)

[pure virtual]

Initializes the hardware device tasks.

Parameters

THwDeviceInitParams & aDevInfo

The device initialization parameters.

NewL(const TFourCC &, const TFourCC &)

CMMFHwDevice *	NewL	(	const TFourCC &	aSrcDatatype,
			const TFourCC &	aDstDataType
		)	[static]

Parameters

const TFourCC & aSrcDatatype
const TFourCC & aDstDataType

NewL(const TFourCC &, const TFourCC &, const TDesC &)

CMMFHwDevice *	NewL	(	const TFourCC &	aSrcDatatype,
			const TFourCC &	aDstDataType,
			const TDesC &	aPreferredSupplier
		)	[static]

Parameters

const TFourCC & aSrcDatatype
const TFourCC & aDstDataType
const TDesC & aPreferredSupplier

NewL(TUid)

CMMFHwDevice *

NewL

(

TUid

aUid

)

[static, inline]

Create a CMMFHwDevice object with a known implementation Uid. Will leave if it is not found (KErrNotFound).

Parameters

TUid aUid

- The Uid of a plugin implementation

NewL(TFileName)

CMMFHwDevice *

NewL

(

TFileName

aFileName

)

[static, inline]

Create a CMMFHwDevice object from .dll. Will leave if dll cannot be loaded (KErrNotFound).

Parameters

TFileName aFileName

Implementation .dll

Pause()

TInt

Pause

(

)

[pure virtual]

Temporarily suspends the current task of decoding or encoding.

SelectByPreference(RImplInfoPtrArray &, const TDesC &)

void	SelectByPreference	(	RImplInfoPtrArray &	aPlugInArray,
			const TDesC &	aPreferredSupplier
		)	[private, static]

Parameters

RImplInfoPtrArray & aPlugInArray
const TDesC & aPreferredSupplier

SetConfig(TTaskConfig &)

TInt

SetConfig

(

TTaskConfig &

aConfig

)

[pure virtual]

Used to configure the sample rate and stereo mode of a CMMFHwDevice plugin.

The configuration of HwDevices is device specific and is not used in any of the reference devices that return KErrNotSupported.

Parameters

TTaskConfig & aConfig

The device configuration.

Start(TDeviceFunc, TDeviceFlow)

TInt	Start	(	TDeviceFunc	aFuncCmd,
			TDeviceFlow	aFlowCmd
		)	[pure virtual]

Starts Encoding or Decoding task(s) based on the parameter specified.

Parameters

TDeviceFunc aFuncCmd	The device function specifying the requested service i.e. decode or encode.
TDeviceFlow aFlowCmd	The device flow directions for the requested service.

Stop()

TInt

Stop

(

)

[pure virtual]

Stops the current on-going task.

StopAndDeleteCodec()

TInt

StopAndDeleteCodec

(

)

[pure virtual]

Call this function to stop and then delete a codec. This is used to allow resources to be freed when using a DSP or similar hardware.

ThisHwBufferEmptied(CMMFBuffer &)

TInt

ThisHwBufferEmptied

(

CMMFBuffer &

aEmptyBufferPtr

)

[pure virtual]

Call this function to notify hardware device implementation that data in aEmptyBufferPtr from encoding is processed.

Parameters

CMMFBuffer & aEmptyBufferPtr

The data buffer processed by the observer.

ThisHwBufferFilled(CMMFBuffer &)

TInt

ThisHwBufferFilled

(

CMMFBuffer &

aFillBufferPtr

)

[pure virtual]

Call this function to notify hardware device implementation that data is available in aFillBufferPtr for decoding.

Parameters

CMMFBuffer & aFillBufferPtr

The data buffer filled by the observer.

Member Data Documentation

TUid iDtor_ID_Key

TUid

iDtor_ID_Key

[private]

MMMFHwDeviceObserver * iHwDeviceObserver

MMMFHwDeviceObserver *

iHwDeviceObserver

[protected]

A pointer to the hardware device observer.