IWMWriterPreprocess::BeginPreprocessingPass method (wmsdkidl.h)
[The feature associated with this page, Windows Media Format 11 SDK, is a legacy feature. It has been superseded by Source Reader and Sink Writer. Source Reader and Sink Writer have been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use Source Reader and Sink Writer instead of Windows Media Format 11 SDK, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]
The BeginPreprocessingPass method prepares the writer to begin preprocessing samples for the specified input stream.
Syntax
HRESULT BeginPreprocessingPass(
[in] DWORD dwInputNum,
[in] DWORD dwFlags
);
Parameters
[in] dwInputNum
DWORD containing the input number that you want to preprocess.
[in] dwFlags
Reserved. Set to zero.
Return value
The method returns an HRESULT. Possible values include, but are not limited to, those in the following table.
| Return code | Description |
|---|---|
|
The method succeeded. |
|
dwInputNum specifies an invalid input number. |
|
The writer is not running.
OR The preprocessor is neither waiting to be run nor stopped in the middle of a pass. OR The preprocessor has already made as many passes as specified by SetNumPreprocessingPasses. OR The input specified is not supported for preprocessing. |
Remarks
To successfully call BeginPreprocessingPass, the preprocessor must be set to make at least one preprocessing pass with a call to SetNumPreprocessingPasses.
The writer must be activated by calling IWMWriter::BeginWriting before you can call this method.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Windows 2000 Professional [desktop apps only],Windows Media Format 9 Series SDK, or later versions of the SDK |
| Minimum supported server | Windows 2000 Server [desktop apps only] |
| Target Platform | Windows |
| Header | wmsdkidl.h (include Wmsdk.h) |
| Library | Wmvcore.lib; WMStubDRM.lib (if you use DRM) |