In this paper, we introduce a crowdsourcing platform that generates subtitles in order to produce barrier-free movies for people with hearing impairments. This paper describes the results of a pilot study that identifies design guidelines and approaches for generating accessible subtitles. We propose ALLSUB, a crowdsourcing platform that enables web users to produce descriptive captions of short video clips. The ultimate goal of this project is to provide opportunities for people with hearing impairment to access much more movies without barriers by gathering works from the community.