ICGetBuffersWanted

The ICGetBuffersWanted macro queries a driver for the number of buffers to allocate. You can use this macro or explicitly call the ICM_GETBUFFERSWANTED message.

DWORD ICGetBuffersWanted(
  hic,         
  lpdwBuffers  
);
 

Parameters

hic

Handle of a driver.

lpdwBuffers

Address to contain the number of samples the driver needs to efficiently render the data.

Return Values

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.

QuickInfo

  Windows NT: Requires version 3.1 or later.
  Windows: Requires Windows 95 or later.
  Windows CE: Unsupported.
  Header: Declared in vfw.h.

See Also

Video Compression Manager Overview, Video Compression Macros, ICM_GETBUFFERSWANTED