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WM_CAP_FILE_ALLOCATE message

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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 Value

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.

Requirements

Requirement Value
Minimum supported client
 Windows 2000 Professional [desktop apps only]
Minimum supported server
 Windows 2000 Server [desktop apps only]
Header
Vfw.h

See also

Video Capture

Video Capture Messages