IKsDataTypeHandler::KsPrepareIoOperation method (ksproxy.h)
The KsPrepareIoOperation method initializes the extended header and prepares the media sample for an I/O operation.
Syntax
HRESULT KsPrepareIoOperation(
[in, out] IMediaSample *Sample,
[in, out] PVOID StreamHeader,
[in] KSIOOPERATION IoOperation
);
Parameters
[in, out] Sample
Pointer to the IMediaSample interface for the associated media sample.
[in, out] StreamHeader
Pointer to a buffer that contains the extended header information.
[in] IoOperation
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. |
Return value
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.
Requirements
| Requirement | Value |
|---|---|
| Target Platform | Desktop |
| Header | ksproxy.h (include Ksproxy.h) |