To backup up videos from Smart Viewer, please do the following.
Go to search mode, once on search mode click on Backup Icon at the bottom left.
You will get a message saying that Backup is not available during playback, click Yes.
Then, please select your channel number date, start time, and end time, please choose the File Format and the folder where to save the video to.
Once the video is being saved on the selected folder you will see three files, these files must be on the same folder or if copy them on a DVR or USB Thumb Drive, click the one with the gray play icon, that is the player if SEC was selected.