MFGetAttributeRatio

Retrieves an attribute whose value is a ratio.

Syntax

HRESULT MFGetAttributeRatio(
         IMFAttributes *pAttributes,
         REFGUID guidKey,
         UINT32 *punNumerator,
         UINT32 *punDenominator
)  

Parameters

pAttributes
Type: IMFAttributes *

Pointer to the IMFAttributes interface of the attribute store.

guidKey
Type: REFGUID 

GUID that identifies which value to retrieve. The attribute type must be MF_ATTRIBUTE_UINT64.

punNumerator
Type: UINT32 *

[out] Receives the numerator of the ratio.

punDenominator
Type: UINT32 *

[out]

Receives the denominator of the ratio.

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

Some attributes specify a ratio as a packed UINT64 value. Use this function to get the numerator and denominator as separate 32-bit values.

Requirements

Header: Declared in mfapi.h.