Search for video files by event.
LONG NET_DVR_FindFileByEvent_V50( LONG lUserID, NET_DVR_SEARCH_EVENT_PARAM_V50 lpSearchEventParam );
[IN] User ID, which is returned by NET_DVR_Login_V40.
[IN] Structure of video file information to search, see details in the structure NET_DVR_SEARCH_EVENT_PARAM_V50.
Return -1 for failure, and return other value as the handle for playback.
If -1 is returned, you can call NET_DVR_GetLastError to get the error code.
After searching video files by event, you can call NET_DVR_FindNextEvent_V50 to get the file information.
The video files searched by event only support playback by time.