After searching around a bit, I found this: https://github.com/Marginal/QLVideo
QuickLook Video
This package allows OSX Finder to display thumbnails, static previews, cover art and metadata for most types of video files.
QuickLook and Spotlight on OSX 10.9 and later understand a limited number of media files - mostly only MPEG audio and video codecs within MPEG container files. This package adds support for wide range of other codecs and "non-native" media file types, including
.asf
,.avi
,.flv
,.mkv
,.rm
,.webm
,.wmf
etc.
It was discussed in this thread here and developed by user Marginal: https://discussions.apple.com/message/26309204#26309204