IMFMediaType::GetRepresentation method
Retrieves an alternative representation of the media type. Currently only the DirectShow AM_MEDIA_TYPE structure is supported.
Syntax
HRESULT GetRepresentation( [in] GUID guidRepresentation, [out] void **ppvRepresentation );
Parameters
- guidRepresentation [in]
-
GUID that specifies the representation to retrieve. The following values are defined.
Value Meaning - AM_MEDIA_TYPE_REPRESENTATION
Convert the media type to a DirectShow AM_MEDIA_TYPE structure. The method selects the most appropriate format structure (pbFormat).
- FORMAT_MFVideoFormat
Convert the media type to a DirectShow AM_MEDIA_TYPE structure with an MFVIDEOFORMAT format structure.
- FORMAT_VideoInfo
Convert the media type to a DirectShow AM_MEDIA_TYPE structure with a VIDEOINFOHEADER format structure.
- FORMAT_VideoInfo2
Convert the media type to a DirectShow AM_MEDIA_TYPE structure with a VIDEOINFOHEADER2 format structure.
- ppvRepresentation [out]
-
Receives a pointer to a structure that contains the representation. The method allocates the memory for the structure. The caller must release the memory by calling IMFMediaType::FreeRepresentation.
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. |
|
The details of the media type do not match the requested representation. |
|
The media type is not valid. |
|
The media type does not support the requested representation. |
Remarks
If you request a specific format structure in the guidRepresentation parameter, such as VIDEOINFOHEADER, you might lose some of the format information.
You can also use the MFInitAMMediaTypeFromMFMediaType function to convert a Media Foundation media type into a DirectShow media type.
This interface is available on the following platforms if the Windows Media Format 11 SDK redistributable components are installed:
- Windows XP with Service Pack 2 (SP2) and later.
- Windows XP Media Center Edition 2005 with KB900325 (Windows XP Media Center Edition 2005) and KB925766 (October 2006 Update Rollup for Windows XP Media Center Edition) installed.
Requirements
|
Minimum supported client |
Windows Vista [desktop apps | Windows Store apps] |
|---|---|
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Minimum supported server |
Windows Server 2008 [desktop apps | Windows Store apps] |
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Header |
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Library |
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See also