If you have a Smart Cloud :
click on Trash in the menu:
Select the video to recover and click on the folder icon "recover in collection"
Select the collection you want to recover the video to and click on Apply
On a dartfish.TV channel:
Change your URL link from www.dartfish.tv/Videos?CR=p(ID of your channel) to www.dartfish.tv/Trash?CR=p(ID of your channel)
Your deleted videos are kept 10 days in the Trash