IWMWriterPreprocess interface (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 It has been superseded by Source Reader and Sink Writer.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 IWMWriterPreprocess interface handles multi-pass encoding. By making more than one pass, the writer can obtain better quality with better compression.
An IWMWriterPreprocess interface exists for every instance of the writer object. You can obtain a pointer to IWMWriterPreprocess with a call to the QueryInterface method of any other interface in the writer object.
Inheritance
The IWMWriterPreprocess interface inherits from the IUnknown interface. IWMWriterPreprocess also has these types of members:
Methods
The IWMWriterPreprocess interface has these methods.
| IWMWriterPreprocess::BeginPreprocessingPass The BeginPreprocessingPass method prepares the writer to begin preprocessing samples for the specified input stream. |
| IWMWriterPreprocess::EndPreprocessingPass The EndPreprocessingPass method ends a preprocessing pass started with a call to IWMWriterPreprocess::BeginPreprocessingPass. |
| IWMWriterPreprocess::GetMaxPreprocessingPasses The GetMaxPreprocessingPasses method retrieves the maximum number of preprocessing passes for a specified input stream. |
| IWMWriterPreprocess::PreprocessSample The PreprocessSample method delivers a sample to the writer for preprocessing. |
| IWMWriterPreprocess::SetNumPreprocessingPasses The SetNumPreprocessingPasses method sets the number of passes to perform on an input. |
Requirements
| Requirement | Value |
|---|---|
| Target Platform | Windows |
| Header | wmsdkidl.h |