IWMReaderCallbackAdvanced::OnOutputPropsChanged method (wmsdkidl.h)

Article
4/26/2023

[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 It has been superseded by Source Reader and Sink Writer.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 OnOutputPropsChanged method indicates that the media properties for the specified output have changed. This change occurs as a result of a call to the IWMReader::SetOutputProps method.

Syntax

HRESULT OnOutputPropsChanged(
  [in] DWORD         dwOutputNum,
  [in] WM_MEDIA_TYPE *pMediaType,
  [in] void          *pvContext
);

Parameters

[in] dwOutputNum

DWORD containing the output number.

[in] pMediaType

Pointer to a WM_MEDIA_TYPE structure.

[in] pvContext

Generic pointer, for use by the application. This pointer is the context pointer given to the IWMReader::Start method.

Return value

To use this method, you must implement it in your application. You can return whatever HRESULT error codes are appropriate to your implementation. For more information about the HRESULT error codes included for use by the Windows Media Format SDK, see Error Codes.

Remarks

This method is called by the reader if the caller gets an asynchronous result from the SetOutputProps method call. The next sample received for this output has these properties. After a call to SetOutputProps and before OnOutputPropsChanged is called, the contents of the media type are undefined.

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)

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