IVMRMixerBitmap::SetAlphaBitmap method (strmif.h)

Article
02/22/2024

[The feature associated with this page, DirectShow, is a legacy feature. It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation. Those features have been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use MediaPlayer, IMFMediaEngine and Audio/Video Capture in Media Foundation instead of DirectShow, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]

The SetAlphaBitmap method specifies a new bitmap image and the source location of the bitmap and how and where it should be rendered on the destination rectangle.

Syntax

HRESULT SetAlphaBitmap(
  [in] const VMRALPHABITMAP *pBmpParms
);

Parameters

[in] pBmpParms

A pointer to a VMRALPHABITMAP structure that contains information about the bitmap.

Return value

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

Return code	Description
E_POINTER	pBmpParms is NULL.
E_INVALIDARG	Invalid argument. See Remarks.
E_OUTOFMEMORY	Could not create a destination DC or DIBSection for the bitmap.
E_FAIL	BitBlt to bitmap surface failed.

Remarks

To remove the bitmap, set the VMRALPHABITMAP structure and call SetAlphaBitmap again.

The method might return E_INVALIDARG for several reasons:

The value of fAlpha is invalid.

Requirements

Requirement	Value
Minimum supported client	Windows XP [desktop apps only]
Minimum supported server	Windows Server 2003 [desktop apps only]
Target Platform	Windows
Header	strmif.h (include Dshow.h)
Library	Strmiids.lib