IWMReader::GetOutputProps method (wmsdkidl.h)

Статья
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 It has been superseded by Source Reader and Sink Writer.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 GetOutputProps method retrieves the current properties of an uncompressed output stream.

Syntax

HRESULT GetOutputProps(
  [in]  DWORD               dwOutputNum,
  [out] IWMOutputMediaProps **ppOutput
);

Parameters

[in] dwOutputNum

DWORD containing the output number.

[out] ppOutput

Pointer to a pointer to an IWMOutputMediaProps interface. This interface belongs to an output media properties object created by a successful call to this method. Any changes made to the output media properties object will have no effect on the output of the reader unless you pass this interface in a call to IWMReader::SetOutputProps.

Return value

The method returns an HRESULT. Possible values include, but are not limited to, those in the following table.

Return code	Description
S_OK	The method succeeded.
E_POINTER	The ppOutput parameter is NULL, or the dwOutputNum parameter is greater than the number of outputs.
E_UNEXPECTED	The method failed for an unspecified reason.

Remarks

The Windows Media codecs can deliver media samples for a stream in a number of formats. For example, the Windows Media Video 9 codec can deliver samples as bitmapped images or as YUV images with varying properties to suit your needs. When you load a file the output properties are set to the default for compressed media type in the stream associated with the output. You can examine the possible output formats by calling IWMReader::GetOutputFormatCount to get the total number of possible formats and then calling IWMReader::GetOutputFormat for each.

This method is synchronous and does not result in any messages being sent to the status callback.

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)

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