All the original video files uploaded by the participants can be downloaded from a folder of your Dropbox account. You only must enable the Dropbox extension (it is included in the 'Video Hosting extension', so you can enable it for free), and automatically all the videos will be stored in a folder of your Dropbox account.

Review the options available enabling the Dropbox integration, as for example, obtaining the videos distributed in several folders depending on segmentation options.