IMFSourceReader::GetPresentationAttribute Method

Gets an attribute from the underlying media source.

Syntax

public:
HRESULT GetPresentationAttribute(
         DWORD dwStreamIndex,
         REFGUID guidAttribute,
         PROPVARIANT *pvarAttribute
)  

Parameters

dwStreamIndex
Type: DWORD 

[in] The stream or object to query. The value can be any of the following.

guidAttribute
Type: REFGUID 

[in] A GUID that identifies the attribute to retrieve. If the dwStreamIndex parameter equals MF_SOURCE_READER_MEDIASOURCE, guidAttribute can specify one of the following:

• A presentation descriptor attribute. For a list of values, see Presentation Descriptor Attributes.
• MF_SOURCE_READER_MEDIASOURCE_CHARACTERISTICS. Use this value to get characteristics flags from the media source.

Otherwise, if the dwStreamIndex parameter specifies a stream, guidAttribute specifies a stream descriptor attribute. For a list of values, see Stream Descriptor Attributes.

pvarAttribute
Type: PROPVARIANT *

[out] A pointer to a PROPVARIANT that receives the value of the attribute. Call the PropVariantClear function to free the PROPVARIANT.

Return value

Type: HRESULT 

If this method succeeds, it returns S_OK. Otherwise, it returns an HRESULT error code.

Refer to Media Foundation return codes.

Remarks

This interface is available on Windows Vista if Platform Update Supplement for Windows Vista is installed.

Requirements

Header: Declared in mfreadwrite.h.