The ICM_DRAW_FLUSH message notifies a rendering driver to render the contents of any image buffers that are waiting to be drawn. You can send this message explicitly or by using the ICDrawFlush macro.
ICM_DRAW_FLUSH
wParam = 0;
lParam = 0;
Returns ICERR_OK if successful or an error otherwise.
This message is used only by hardware that performs its own asynchronous decompression, timing, and drawing.
Windows NT: Requires version 3.1 or later.
Windows: Requires Windows 95 or later.
Windows CE: Unsupported.
Header: Declared in vfw.h.
Video Compression Manager Overview, Video Compression Messages, ICDrawFlush