YouTube now supports closed caption text files that can be displayed inside video clips. The tech spec is here. Of course, the Googletards behind YouTube tout the feature's value for science, such as this English assist for a heavily Dutch-inflected talk by physics hero Walter Llewin. (Sorry, but the captions don't work on embedded clips yet. To activate subtitles, play the video on YouTube and click the button in the lower right corner of the screen.) I give it a week at max until video remixers are using captions Joe Isuzu-style.