Last modified: 2012-12-31 10:26:22 UTC
TimedMediaHandler outputs <video> elements with multiple <source> subelements directly into HTML, which allows browsers without JavaScript -- or any browser on the mobile interface where we have less JavaScript -- to play the videos directly. However, the <source> elements are not labeled with "type" attributes, so the browser can't tell which source it should go for. Instead it seems to default to the first source, which appears to be the original file. This seems to have two major problems: 1) original source may be HD and waste resources on a small-screen or low-bandwidth device 2) platforms such as Android 4.x support WebM but not Ogg Theora; by defaulting to the Ogg version the video doesn't play. In theory, having "type" attributes ought to allow Chrome to select one of the WebM versions instead; this'll probably also be needed if/when we do H.264 transcodes for browsers that don't support Ogg or WebM.
added here: https://gerrit.wikimedia.org/r/#/c/38665/