Class CMMFSwCodec

class CMMFSwCodec : public CBase;

Description

Class for a software codec used by the CMMFSwCodecWrapper class to make the CMMFSwCodec a CMMFHwDevice plugin. The CMMFSwCodec processes source data in a certain fourCC coding type and converts it to a destination buffer of another fourCC coding type.

A CMMFSwCodec object would usually not be instantiated directly but instead would be instantiated via the CMMFSwCodecWrapper class's Codec() method.

The processing of the data is handled by the codecs CMMFSwCodec::ProcessL(const CMMFBuffer &,CMMFBuffer &) member. The intention is that the source buffer for conversion is converted to the appropriate coding type in the destination buffer. The size of the buffers passed in are determined by CMMFSwCodec::SourceBufferSize() and CMMFSwCodec::SinkBufferSize() methods. The buffer sizes should be chosen such that the CMMFSwCodec::ProcessL(const CMMFBuffer &,CMMFBuffer &) method can be guaranteed to have enough destination buffer to completely process one source buffer.

The ProcessL should return a CMMFSwCodec::TCodecProcessResult returning the number of source bytes processed and the number of destination bytes processed along with a process result code defined thus:

• EProcessComplete: the codec processed all the source data into the sink buffer

• EProcessIncomplete: the codec filled sink buffer before all the source buffer was processed

• EDstNotFilled: the codec processed the source buffer but the sink buffer was not filled

• EEndOfData: the codec detected the end data - all source data in processed but sink may not be full

• EProcessError: the codec process error condition

Unlike the 7.0s CMMFCodec::ProcessL(const CMMFBuffer &,CMMFBuffer &) method, the CMMFSwCodec::ProcessL(const CMMFBuffer &,CMMFBuffer &) method should not return EProcessIncomplete as this case is not handled by the CMMFSwCodecWrapper.

Derivation

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

• CMMFSwCodec - ...

Members

Defined in CMMFSwCodec:

• ProcessL(const CMMFBuffer &,CMMFBuffer &)Processes the data in the specified source buffer and writes the processed data ...
• SinkBufferSize()Gets the max size of the sink (destination) buffer passed into the CMMFSwCodec::...
• SourceBufferSize()Gets the max size of the source buffer passed into the CMMFSwCodec::ProcessL(con...
• TCodecProcessResult...

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...

virtual TCodecProcessResult ProcessL(const CMMFBuffer &aSource, CMMFBuffer &aDest)=0;

Description

Processes the data in the specified source buffer and writes the processed data to the specified destination buffer.

This function is synchronous, when the function returns the data has been processed. This is a virtual function that each derived class must implement.

Parameters

const CMMFBuffer &aSource The source buffer containing data to encode or decode. CMMFBuffer &aDest The destination buffer to hold the data after encoding or decoding.

Return value

CMMFSwCodec::TCodecProcessResult The result of the processing.

See also:

• CMMFSwCodec::TCodecProcessResult...

virtual TUint SourceBufferSize()=0;

Description

Gets the max size of the source buffer passed into the CMMFSwCodec::ProcessL(const CMMFBuffer &,CMMFBuffer &) function.

Note that this means that this is the Max size of each buffer passed to the codec. The actual size of the data could be less than the max size. This is a virtual function that each derived class must implement.

Return value

TUint The max size of the source buffer in bytes.

virtual TUint SinkBufferSize()=0;

Description

Gets the max size of the sink (destination) buffer passed into the CMMFSwCodec::ProcessL(const CMMFBuffer &,CMMFBuffer &) method.

Note that this means that this is the Max size of each buffer passed to the codec. The actual size of the data written to this buffer could be less than the max size. This is a virtual function that each derived class must implement.

Return value

TUint The max size of the sink buffer in bytes.

class TCodecProcessResult;

Description

Indicates the result of processing data from the source buffer to a destination buffer and provides functions to compare the result code. The CMMFSwCodec buffer sizes should be set to return EProcessComplete The other return codes are to keep the ProcessL method compatible with the 7.0s CMMFCodec API.

Members

Defined in CMMFSwCodec::TCodecProcessResult:

• EDstNotFilledCould not fill the destination buffer because the source buffer has been emptied...
• EEndOfDataCodec came across an end of data.
• EProcessCompleteThe codec has successfully completed its processing.
• EProcessErrorAn error occured.
• EProcessIncompleteCould not empty the source buffer because the destination buffer became full.
• TCodecProcessResult()Default constructor.
• TCodecProcessResultStatusFlag to track the codec's processing status.
• iCodecProcessStatusThe codec's processing status
• iDstBytesAddedThe number of bytes added to the destination buffer
• iSrcBytesProcessedThe number of source bytes processed
• operator!=(const TCodecProcessResultStatus)constOverloaded operator to test inequality.
• operator==(const TCodecProcessResultStatus)constOverloaded operator to test equality.

Construction and destruction

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TCodecProcessResult()

inline TCodecProcessResult();

Description

Default constructor.

Member functions

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operator==(const TCodecProcessResultStatus)const

inline TBool operator==(const TCodecProcessResultStatus aStatus) const;

Description

Overloaded operator to test equality.

Parameters

const CMMFSwCodec::TCodecProcessResult::TCodecProcessResultStatus aStatus

Return value

TBool

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operator!=(const TCodecProcessResultStatus)const

inline TBool operator!=(const TCodecProcessResultStatus aStatus) const;

Description

Overloaded operator to test inequality.

Parameters

const CMMFSwCodec::TCodecProcessResult::TCodecProcessResultStatus aStatus

Return value

TBool

Member enumerations

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Enum TCodecProcessResultStatus

TCodecProcessResultStatus

Description

Flag to track the codec's processing status.

EProcessComplete The codec has successfully completed its processing. EProcessIncomplete Could not empty the source buffer because the destination buffer became full. EEndOfData Codec came across an end of data. EDstNotFilled Could not fill the destination buffer because the source buffer has been emptied. EProcessError An error occured.

Member data

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iCodecProcessStatus

TCodecProcessResultStatus iCodecProcessStatus;

Description

The codec's processing status

See also:

• CMMFSwCodec::TCodecProcessResult::TCodecProcessResultStatusFlag to track the codec's processing status.

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iSrcBytesProcessed

TUint iSrcBytesProcessed;

Description

The number of source bytes processed

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iDstBytesAdded

TUint iDstBytesAdded;

Description

The number of bytes added to the destination buffer