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IVMRMixerControl::SetAlpha

  • Artigo
 
Microsoft DirectShow 9.0

IVMRMixerControl::SetAlpha

The SetAlpha method sets a constant alpha value that is applied to this video stream.

Syntax

  HRESULT SetAlpha(

  
  DWORD
  
  dwStreamID
  
  float
  
  Alpha

  );

Parameters

dwStreamID

[in] Specifies the input stream.

Alpha

[in]  Specifies the alpha blending value to be applied to all the pixels in this stream.

Return Values

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

Error Code Description
VFW_E_NOT_CONNECTED The pin is not connected.

Remarks

The alpha value specified can be between 0.0 (fully transparent) and 1.0 (full opaque).

Requirements

Header: Declared in Strmif.h; include Dshow.h.

Library: Use Strmiids.lib.

See Also