IOverlay::SetColorKey

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Microsoft DirectShow 9.0

IOverlay::SetColorKey

The SetColorKey method changes the color key.

Syntax

  HRESULT SetColorKey(
  COLORKEY *pColorKey
);

Parameters

pColorKey

[in, out] Pointer to the color key value to be set. If successful, the actual color key value selected is copied to this parameter.

Return Value

Returns S_OK if successful, E_POINTER if pColorKey is NULL, or E_INVALIDARG if the value of pColorKey is invalid for the current palette or pixel format.

Remarks

If you change the color key using the SetColorKey method, all the advise links will receive an IOverlayNotify::OnColorKeyChange callback method with the new color.

When using IOverlay::Advise on a palettized display, a filter can either install a color key (using SetColorKey) or install a palette (using IOverlay::SetPalette), but not both. This is because color keys in this mode require a palette to be realized that would conflict with SetPalette. Color keys can be uninstalled by requesting a color key with the CK_NOCOLORKEY flag. Likewise, any palette installed through SetPalette can be uninstalled by calling SetPalette and passing in null parameters (that is, SetPalette(0,NULL)).

Trying to set a palette when a color key is installed returns a VFW_E_PALETTE_SET error. Trying to set a color key when a palette is installed returns VFW_E_COLOR_KEY_SET.

Requirements

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

Library: Use Strmiids.lib.

See Also