ICM_GETBUFFERSWANTED message
The ICM_GETBUFFERSWANTED message queries a driver for the number of buffers to allocate. You can send this message explicitly or by using the ICGetBuffersWanted macro.
ICM_GETBUFFERSWANTED
wParam = (DWORD_PTR) (LPVOID) lpdwBuffers;
lParam = 0;
Parameters
-
lpdwBuffers
-
Address to contain the number of samples the driver needs to efficiently render the data.
Return Value
Returns ICERR_OK if successful or ICERR_UNSUPPORTED otherwise.
Remarks
This message is used by drivers that use hardware to render data and want to ensure a minimal time lag caused by waiting for buffers to arrive. For example, if a driver controls a video decompression board that can hold 10 frames of video, it could return 10 for this message. This instructs applications to try to stay 10 frames ahead of the frame it currently needs.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client |
Windows 2000 Professional [desktop apps only] |
| Minimum supported server |
Windows 2000 Server [desktop apps only] |
| Header |
|