Class CMMFDataBuffer

class CMMFDataBuffer : public CMMFBuffer;

Description

This class is an abstract class for databuffers that can be presented in the form of a descriptor. A constructor is provided which instantiates a CMMFDescriptorBuffer buffer by default.

Derivation

• CBase - Base class for all classes to be instantiated on the heap.

• CMMFBuffer - Abstract representation of a buffer to contain multimedia data.

• CMMFDataBuffer - ...

Members

Defined in CMMFDataBuffer:

• BufferSize()constReturns the buffer size, in bytes.
• CMMFDataBuffer(TUid)Protected constructor.
• Data()Returns a reference to the data contained in the buffer (non const version).
• Data()constReturns a reference to the data contained in the buffer (const version).
• NewL()Method to instantiate a CMMFDataBuffer defaults to a CMMFDescriptorBuffer to mai...
• NewL(TInt)Method to instantiate a CMMFDataBuffer defaults to a CMMFDescriptorBuffer by def...
• SetRequestSizeL(TInt)Sets the request size.
• ~CMMFDataBuffer()Destructor.

Inherited from CBase:

• Delete(CBase *)Deletes the specified object.
• Extension_(TUint,TAny *&,TAny *)Extension function
• operator new(TUint)Allocates the object from the heap and then initialises its contents to binary z...
• operator new(TUint,TAny *)Initialises the object to binary zeroes.
• operator new(TUint,TLeave)Allocates the object from the heap and then initialises its contents to binary z...
• operator new(TUint,TLeave,TUint)Allocates the object from the heap and then initialises its contents to binary z...
• operator new(TUint,TUint)Allocates the object from the heap and then initialises its contents to binary z...

Inherited from CMMFBuffer:

• CMMFBuffer(TUid)
• FrameNumber()constReturns the frame number.
• IsFileServerSafe(TUid)Static method which returns ETrue if the buffer UID is a buffer that is safe to ...
• IsSupportedDataBuffer(TUid)Static method which returns ETrue if the buffer UID is a supported CMMFDataBuffe...
• LastBuffer()constTests whether the buffer is the last buffer.
• NextFrame()Sets the buffer as the next frame.
• Position()constReturns the current buffer read/write position. Used as read/write position on a...
• RequestSize()constReturns the size of data processed by sink or data needed by source.
• SetFrameNumber(TUint)Sets the frame number. This is used for repositioning.
• SetLastBuffer(TBool)Sets the buffer as the last buffer.
• SetPosition(TUint)Sets the current buffer read/write position. Used as read/write position on a bu...
• SetStatus(TBufferStatus)Sets the buffer's status.
• SetTimeToPlay(TTimeIntervalMicroSeconds)Sets the buffer timestamp, in microseconds.
• Status()Returns the buffer's status.
• TimeToPlay()constReturns the buffer timestamp, in microseconds.
• Type()constReturns the buffer type.
• iFrameNumberThe frame number.
• iLastBufferIndicates if this is the last buffer. ETrue if it is.
• iPositionUsed to store the current read/write position. Required when the codec and data ...
• iRequestSizeStores Request size, needed for dynamic buffer length.
• iStatusThe current buffer status.
• iTimeToPlayThe buffer timestamp, in microseconds.
• iTypeThe buffer type.

See also:

• CMMFDescriptorBuffer...

IMPORT_C static CMMFDataBuffer* NewL();

Description

Method to instantiate a CMMFDataBuffer defaults to a CMMFDescriptorBuffer to maintain buffer compatiblity with MFAD ie. instantiating a CMMFDataBuffer defaults to creating a CMMFDescriptorBuffer. This NewL creates a CMMFDescriptorBuffer with a default size of 32 bytes.

Return value

CMMFDataBuffer * A pointer to a new CMMFDescriptorBuffer.

IMPORT_C static CMMFDataBuffer* NewL(TInt aMaxBufferSize);

Description

Method to instantiate a CMMFDataBuffer defaults to a CMMFDescriptorBuffer by default to maintain buffer compatiblity with MFAD ie. instantiating a CMMFDataBuffer defaults to creating a CMMFDescriptorBuffer. This NewL creates a CMMFDescriptorBuffer with a size of aMaxBufferSize bytes.

Parameters

TInt aMaxBufferSize The size in bytes of the descriptor buffer to be created.

Return value

CMMFDataBuffer * A pointer to a new CMMFDescriptorBuffer.

inline virtual ~CMMFDataBuffer();

Description

Destructor.

protected: inline CMMFDataBuffer(TUid aType);

Description

Protected constructor.

Parameters

TUid aType

virtual TDes8& Data()=0;

Description

Returns a reference to the data contained in the buffer (non const version).

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

Return value

TDes8 & A reference to the buffer.

virtual const TDesC8& Data() const=0;

Description

Returns a reference to the data contained in the buffer (const version).

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

Return value

const TDesC8 & A reference to the buffer.

virtual TUint BufferSize() const=0;

Description

Returns the buffer size, in bytes.

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

Return value

TUint The buffer size in bytes.

virtual void SetRequestSizeL(TInt aSize)=0;

Description

Sets the request size.

Used where a component, such as a data source, may not be able to write to the entire maximum length of the buffer (variable bit rate codecs for example).

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

Parameters

TInt aSize The requested size, in bytes.