Class CMdaImageDescToBitmapUtility

CMdaImageDescToBitmapUtility

Support

Supported from 5.0

Description

Implements format conversion of a descriptor-based image to a bitmap.

The class provides functions to create an instance of this conversion utility and to open and prepare the image data.

Conversion is performed using the image conversion utility interface.

Derivation

CActive The core class of the active object abstraction CBase Base class for all classes to be instantiated on the heap CMdaImageDataReadUtility Base class used in the derivation of CMdaImageDescToBitmapUtility and CMdaImageFileToBitmapUtility CMdaImageDescToBitmapUtility Implements format conversion of a descriptor-based image to a bitmap CMdaImageUtility The abstract base class for the image conversion utilities CMdaResource Base class used in the derivation of CMdaImageUtility MMdaObjectStateChangeObserver An interface class for handling the change of state of an audio data sample object

Defined in CMdaImageDescToBitmapUtility:
NewL(), OpenL()

Inherited from CActive:
Cancel(), Deque(), DoCancel(), EPriorityHigh, EPriorityIdle, EPriorityLow, EPriorityStandard, EPriorityUserInput, IsActive(), IsAdded(), Priority(), RunError(), RunL(), SetActive(), SetPriority(), TPriority, iStatus

Inherited from CBase:
operator new()

Inherited from CMdaImageUtility:
CancelConvertL(), Close(), ConvertL(), FrameCount(), FrameInfo()

Inherited from MMdaObjectStateChangeObserver:
MoscoStateChangeEvent()

static CMdaImageDescToBitmapUtility* NewL(MMdaImageUtilObserver& aObserver,CMdaServer* aServer = NULL);

Description

Constructs a new instance of the descriptor-based image to bitmap conversion utility object.

The function leaves if this object cannot be created.

Parameters

MMdaImageUtilObserver& aObserver The image utility observer interface CMdaServer* aServer = NULL A pointer to a server object. The default is NULL which means that one is automatically constructed and owned by this conversion utility object. If not NULL, the client must construct, and be responsible for, the server object. This option may be more efficient if a number of conversion utility objects are to be created.

Return value

CMdaImageDescToBitmapUtility* Pointer to the new instance of the descriptor-based image to bitmap conversion utility

void OpenL(const TDesC8& aDescriptor,TMdaClipFormat* aFormat = NULL,TMdaPackage* aCodec = NULL,TMdaPackage* aExtra = NULL);

Description

Opens the descriptor-based image.

The function is asynchronous. When the open operation is complete, successfully or otherwise, the callback function MMdaImageUtilObserver::MiuoOpenComplete() is called.

Open must complete successfully before starting any conversion operation. The function can complete with KErrUnderflow, if there is insufficient information in the descriptor. Typically, this occurs when using the descriptor as a cache. In this situation, open should be performed repeatedly until the descriptor has accumulated enough information for the operation to complete with KErrNone.

Notes

The optional parameters can be used to force the Media Server to interpret the descriptor-based data as being of a specific type. This is necessary for formats such as WAP wireless bitmap where the supplied descriptor does not contain a uniquely recognisable signature.

Parameters

const TDesC8& aDescriptor A descriptor containing the image. TMdaClipFormat* aFormat = NULL The data format. This is optional. TMdaPackage* aCodec = NULL The codec to use. This is optional. TMdaPackage* aExtra = NULL Additional information which the Media Server may need to recognise the data format. This is optional.

Leave codes

When for fA -> fB Opening can leave with KErrUYnderflow