typedef struct videohdr_tag {
    LPBYTE      lpData;                 
    DWORD       dwBufferLength;         
    DWORD       dwBytesUsed;            
    DWORD       dwTimeCaptured;         
    DWORD_PTR   dwUser;                 
    DWORD       dwFlags;                
    DWORD_PTR   dwReserved[4];          
} VIDEOHDR, NEAR *PVIDEOHDR, FAR * LPVIDEOHDR;