GetChunkSize

Description

Returns the size of the data associated with the specified chunk feature.


Syntax

[VB]
Value=objActiveGige.GetChunkSize( Name )

[C/C++]
HRESULT GetChunkSize( bstr Name, long* pValue );


Data Types [VB]


Return value: Variant (pointer)


Parameters [C/C++]

Name [in]

String specifying the name of the chunk feature

pValue [out,retval]

Pointer to the size of the chunk data in bytes.

Return Values

S_OK

Success

E_FAIL

Failure.

E_INVALIDARG

Invalid input arguments.

Example

This fragment of the C++ code grabs a frame, retrieves a pointer to the chunk data and copies them into a byte array.

VARIANT var; LONG var_size;
char buffer[255]; short v;

pActiveGige->SetFeature( OLESTR("ChunkEnable"), 1);
pActiveGige->Grab(&v);

pActiveGige->GetChunkPointer( OLESTR( "ChunkInputStatusAtLineTriggerValue" ), &var);
pActiveGige->GetChunkSize(OLESTR( "ChunkInputStatusAtLineTriggerValue" ), &var_size);
memcpy( buffer, (BYTE*)var.byref, var_size);


Remarks

Chunks are tagged blocks of auxilary data that are transmitted along with each image frame. The GetChunkSize and GetChunkPointer methods provides the most efficient way to quickly access the chunk data in pointer-aware programming languages. It is especially useful for accessing data associated with array-type features.

Note that when several chunk features share the same Chunk ID, this method will return the size of the data block identified by the given Chunk ID. For more information on the chunk data refer to "GigE Vision Video Streaming and Device Control Over Ethernet Standard" published by the Automated Imaging Association.