We use dedicated conference reviewing software with web front-ends to review videos after they are recorded. These allow end users to log in and review the videos online. Typically the review software also manage transcoding the video files to the desired publishing format and quality. The two systems we recommend (veyepar and SReview) handle transcoding. Their respective documentations are linked here:
Since it is a bit complicated to set up, if you are planning a Debian event, contact us and we might be able to set it up for you.