A browser efficiently extracts media from a video presented through a web application having a different domain from a media server providing the web application while complying with cross-origin resource restrictions. A video portion is selected, and a header portion of the video is identified. A truncated video portion, which includes the selected video portion and a video portion contiguous to the selected video portion, is loaded into memory. A truncated video file is generated including the truncated video portion and a truncated video header. The truncated video file is encoded as a video tag included in the web application, and the media corresponding to the selected video portion is extracted by transcoding the truncated video file in the video tag. A server may also extract the media by loading the truncated video portion, generating the truncated video file, and transcoding the truncated video file to obtain the media.