IAAFEssenceFormat Interface Reference

The AAFEssenceFormat class represents a collection of parameters (such as image height/width, audio sample width) which describes a piece of essence. More...

List of all members.

Public Member Functions
HRESULT	AddFormatSpecifier ([in] aafUID_constref essenceFormatCode,[in] aafInt32 valueSize,[in, size_is(valueSize)] aafDataBuffer_t value)
	Appends a format specifier to the AAFEssenceFormat.
HRESULT	GetFormatSpecifier ([in] aafUID_constref essenceFormatCode,[in] aafInt32 valueSize,[out, size_is(valueSize), length_is(*bytesRead)] aafDataBuffer_t value,[out] aafInt32 *bytesRead)
	The data value is returned in a preallocated buffer of size valueSize.
HRESULT	NumFormatSpecifiers ([out] aafInt32 *numSpecifiers)
	The data value is returned in a preallocated buffer of size valueSize.
HRESULT	GetIndexedFormatSpecifier ([in] aafInt32 index,[out] aafUID_t *essenceFormatCode,[in] aafInt32 valueSize,[out, size_is(valueSize), length_is(*bytesRead)] aafDataBuffer_t value,[out] aafInt32 *bytesRead)
	The data value is returned in a preallocated buffer of size valueSize.

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Detailed Description

The AAFEssenceFormat class represents a collection of parameters (such as image height/width, audio sample width) which describes a piece of essence.

Each parameter is specified by an AUID, and contains a variable length piece of data.

When creating a piece of essence, you should call AddFormatSpecifier() for each required or known parameter, and the codec will supply defaults for other optional parameters.

In addition to the specific error results listed for each method, all methods in this interface may also return one of the following values:

AAFRESULT_NOMEMORY

• insufficient system memory is available to perform the operation.

AAFRESULT_NOT_INITIALIZED

• This object has not yet had Initialize() called on it through this object's primary interface.

Definition at line 8771 of file AAF.idl.

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Member Function Documentation

HRESULT IAAFEssenceFormat::AddFormatSpecifier	(	[in] aafUID_constref	essenceFormatCode,
		[in] aafInt32	valueSize,
		[in, size_is(valueSize)] aafDataBuffer_t	value
	)

Appends a format specifier to the AAFEssenceFormat.

If an essenceFormatCode has already been added, then this call replaces the value, otherwise the value is appended.

The value data is passed in as a void * through the "value" argument. The size of the value must be passed through the valueSize argument.

Parameters:

essenceFormatCode	[in] From aaddefuids.h
valueSize	[in] Size of preallocated buffer
value	[in, size_is(valueSize)] Value data

HRESULT IAAFEssenceFormat::GetFormatSpecifier	(	[in] aafUID_constref	essenceFormatCode,
		[in] aafInt32	valueSize,
		[out, size_is(valueSize), length_is(*bytesRead)] aafDataBuffer_t	value,
		[out] aafInt32 *	bytesRead
	)

The data value is returned in a preallocated buffer of size valueSize.

The actual number of bytes read is returned in bytesRead. If the buffer is not big enough to return the entire value, an error is returned.

Parameters:

essenceFormatCode	[in] From aaddefuids.h
valueSize	[in] Size of preallocated buffer
value	[out, size_is(valueSize),length_is(*bytesRead)] Preallocated buffer to hold value
bytesRead	[out] Number of actual bytes read

HRESULT IAAFEssenceFormat::GetIndexedFormatSpecifier	(	[in] aafInt32	index,
		[out] aafUID_t *	essenceFormatCode,
		[in] aafInt32	valueSize,
		[out, size_is(valueSize), length_is(*bytesRead)] aafDataBuffer_t	value,
		[out] aafInt32 *	bytesRead
	)

The data value is returned in a preallocated buffer of size valueSize.

Parameters:

index	[in] 0-based index
essenceFormatCode	[out] From aaddefuids.h
valueSize	[in] Size of preallocated buffer
value	[out, size_is(valueSize),length_is(*bytesRead)] Preallocated buffer to hold value
bytesRead	[out] Number of actual bytes read

HRESULT IAAFEssenceFormat::NumFormatSpecifiers

(

[out] aafInt32 *

numSpecifiers

)

The data value is returned in a preallocated buffer of size valueSize.

Parameters:

numSpecifiers

[out] The number of specifiers present.