IVMRSurfaceAllocator::PrepareSurface method (strmif.h)
[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 It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation.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 PrepareSurface method prepares the DirectDraw surface to have the next video frame decoded into it.
Syntax
HRESULT PrepareSurface(
[in] DWORD_PTR dwUserID,
[in] LPDIRECTDRAWSURFACE7 lpSurface,
[in] DWORD dwSurfaceFlags
);
Parameters
[in] dwUserID
An application-defined DWORD_PTR cookie that uniquely identifies this instance of the VMR for use in scenarios when one instance of the allocator-presenter is used with multiple VMR instances.
[in] lpSurface
Specifies the DirectDraw surface
[in] dwSurfaceFlags
Double word containing the surface flags. See Remarks.
Return value
If the method succeeds, it returns S_OK. If it fails, it returns an error code.
Remarks
The only flag that the VMR currently checks here is AM_GBF_NOTASYNCPOINT (0x00000002), which indicates that you are not going to fill this buffer with a sync point (keyframe).
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Windows XP with SP1 [desktop apps only] |
| Minimum supported server | Windows Server 2003 [desktop apps only] |
| Target Platform | Windows |
| Header | strmif.h (include Dshow.h) |
| Library | Strmiids.lib |