Microsoft DirectX 8.1 (C++)

IVMRMixerControl::GetAlpha

This topic applies to Windows XP Home Edition and Windows XP Professional only.

The GetAlpha method retrieves the constant alpha value that is applied to this video stream.

Syntax

HRESULT GetAlpha(
  DWORD dwStreamID,
  float*  pAlpha
);

Parameters

dwStreamID

[in] Specifies the input stream.

pAlpha

[out]  Pointer to a variable of type float that receives the current alpha value.

Return Values

If the method succeeds, it returns S_OK. If it fails, it returns an error code.

Error Code Description
E_POINTER pAlpha is invalid.
VFW_E_NOT_CONNECTED The pin is not connected.

See Also