Example:
GET http://192.168.15.182:80/getarchivetaskstatus?archivetaskid=104b38d4-07d7-4d2f-84da-49b3e255d2bf

Response:

{

    "Percents" : 100,

    "Url" : "http://192.168.15.182:80/download?file=104b38d4-07d7-4d2f-84da-49b3e255d2bf",

    "CameraId" : "1",

    "From" : "2016-06-27T15:10:00.000+03:00",

    "To" : "2016-06-27T15:11:00.000+03:00",

    "ArchiveTaskId" : "104b38d4-07d7-4d2f-84da-49b3e255d2bf",

    "ErrorMessage" : "null",

    "State" : "ReadyForDownload"

}

The required mp4 file can be downloaded using the link in the URL bar.