WM_CAP_FILE_ALLOCATE

The WM_CAP_FILE_ALLOCATE message creates (preallocates) a capture file of a specified size. You can send this message explicitly or by using the capFileAlloc macro.

WM_CAP_FILE_ALLOCATE 
wParam = (WPARAM) 0; 
lParam = (LPARAM) (DWORD) (dwSize); 
 

Parameters

dwSize

Size, in bytes, to create the capture file.

Return Values

Returns TRUE if successful or FALSE otherwise.

If an error occurs and an error callback function is set using the WM_CAP_SET_CALLBACK_ERROR message, the error callback function is called.

Remarks

You can improve streaming capture performance significantly by preallocating a capture file large enough to store an entire video clip and by defragmenting the capture file before capturing the clip.

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 Capture Overview, Video Capture Messages, capFileAlloc, WM_CAP_SET_CALLBACK_ERROR