Edit:
"Videos are uploaded to the server but do not have playback controls."
If you're using Video.js and you aren't getting any player controls appearing properly (assuming you're still using the code you specified in the reply to comments), it's most likely because you've not included the CSS file above the video.js include, as specified in the Videojs documentation
<link href="http://vjs.zencdn.net/c/video-js.css" rel="stylesheet">
If that's not the issue, and videos aren't playing back at all (as you originally stated), then it may be potentially something else that's crossed my mind. Seeing as you're a Chrome user, if you right click on your video page, go to inspect element, then click the console tab.
If you've got anything to do with the wrong Mime type being sent, then information here may help:
HTML5 video (mp4 and ogv) problems in Safari and Firefox - but Chrome is all good
Specifically this reply
I'm not sure I can help anymore without further explanation / information.
Specify the type of video.
E.g.
<source scr="trial.mp4" type="video/mp4">