IWMWriterSink::OnHeader 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 It has been superseded by Source Reader and Sink Writer.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 OnHeader method is called by the writer when the ASF header is ready for the sink.
Syntax
HRESULT OnHeader(
[in] INSSBuffer *pHeader
);
Parameters
[in] pHeader
Pointer to an INSSBuffer interface on an object containing the ASF header.
Return value
This method is implemented by the application. It should always return S_OK.
Remarks
The ASF header will always be sent before any data units, as the header is required for reading the content. The writer may send the header more than once for a given file. If possible, your sink should write any headers received.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Windows 2000 Professional [desktop apps only],Windows Media Format 7 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) |