Changes

The default pattern for the file name is '''$Y-$M-$D_$H$N$S''' so using the default pattern, output file name for a recording process that started at 14/05/2017 00:48:49 is '''2017-05-14_004849.mp4'''. If a file with the same name already exist, an underscore followed by a number will be added to the end of the name to make it unique. (e.g. 2017-05-14_004849_0001.mp4)