| Microsoft DirectX 8.1 (C++) |
The SetRedrawAlways method sets whether the renderer should redraw the whole output bitmap for each sample.
Syntax
HRESULT SetRedrawAlways(
BOOL bOption
);
Parameters
bOption
Value indicating whether the whole bitmap should be redrawn. TRUE indicates redraw always, FALSE means do not redraw always.
Return Values
Returns an HRESULT value that depends on the implementation of the interface. The current DirectShow implementation returns E_INVALIDARG if a parameter is invalid or NOERROR to indicate success.
Remarks
Call this method from your filter if it dirties the buffer that it provides to the Line 21 Decoder filter. Typically, a mixer filter resides in the filter graph directly downstream from the Line 21 Decoder filter. The mixer filter should call this method and set bOption to TRUE to ensure the entire bitmap is redrawn properly.
A downstream mixer (or any filter that needs to do so) should only call this method with bOption set to TRUE if it provides the same buffer to the Line 21 Decoder as it uses to mix secondary video streams(s).
Redrawing (setting bOption to TRUE) degrades performance and increases CPU load, because it negates any potential optimizations.
See Also