The IDirectDrawVideoPort::Flip method instructs the DirectDrawVideoPort object to write the next frame of video to a new surface.
HRESULT Flip(
  LPDIRECTDRAWSURFACE lpDDSurface,  
  DWORD dwFlags                     
);
 If the method succeeds, the return value is DD_OK.
If the method fails, the return value may be one of the following error values:
| DDERR_INVALIDOBJECT | 
| DDERR_INVALIDPARAMS | 
This method can be used to prevent tearing. Calls to IDirectDrawVideoPort::Flip are asynchronous—the actual flip operation will always be synchronized with the vertical blank of the video signal.
  Windows NT/2000: Requires Windows 2000.
  Windows 95/98: Requires Windows 95 or later. Available as a redistributable for Windows 95.
  Header: Declared in dvp.h.
  Import Library: Use ddraw.lib.