nf-ksproxy-iksdatatypehandler-ksprepareiooperation.md

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NF:ksproxy.IKsDataTypeHandler.KsPrepareIoOperation	IKsDataTypeHandler::KsPrepareIoOperation (ksproxy.h)	The KsPrepareIoOperation method initializes the extended header and prepares the media sample for an I/O operation.	stream	03/07/2023	IKsDataTypeHandler::KsPrepareIoOperation	IKsDataTypeHandler interface [Streaming Media Devices],KsPrepareIoOperation method, IKsDataTypeHandler.KsPrepareIoOperation, IKsDataTypeHandler::KsPrepareIoOperation, KsPrepareIoOperation, KsPrepareIoOperation method [Streaming Media Devices], KsPrepareIoOperation method [Streaming Media Devices],IKsDataTypeHandler interface, ksproxy/IKsDataTypeHandler::KsPrepareIoOperation, ksproxy_24b2f3a8-8870-434e-9f15-71fa363d3215.xml, stream.iksdatatypehandler_ksprepareiooperation	ksproxy.h	Ksproxy.h	Desktop															Windows		IKsDataTypeHandler::KsPrepareIoOperation ksproxy/IKsDataTypeHandler::KsPrepareIoOperation	APIRef kbSyntax	COM	ksproxy.h	IKsDataTypeHandler::KsPrepareIoOperation

-description

The KsPrepareIoOperation method initializes the extended header and prepares the media sample for an I/O operation.

-parameters

-param Sample [in, out]

Pointer to the IMediaSample interface for the associated media sample.

-param StreamHeader [in, out]

Pointer to a buffer that contains the extended header information.

-param IoOperation [in]

Value that specifies the type of I/O operation. This value can be one of the following values from the KSIOOPERATION enumerated type:

Value	Description
KsIoOperation_Write	Write data to stream.
KsIoOperation_Read	Read data from stream.

-returns

Returns NOERROR if successful; otherwise, returns an error code. If the stream's major type is KSDATAFORMAT_TYPE_AUDIO, a KsPrepareIoOperation call is inapplicable, so KsPrepareIoOperation automatically returns NOERROR.

-remarks

The client only calls KsPrepareIoOperation if the data type handler indicated to the client the existence of extended header information in a call to the IKsDataTypeHandler::KsQueryExtendedSize method.

For more information about IMediaSample, see the Microsoft Windows SDK documentation.

-see-also

IKsDataTypeHandler::KsQueryExtendedSize