Just wanted to bring this to everyone's attention here, adding support for full-size video playback in the Canvas mobile app is open for voting now, please come over and vote for this if videos are an important part of your curriculum:
This is a major problem for us at our institution, we have a lot of instructional videos featuring software UIs and the controls are very difficult to see in the tiny videos that the Canvas app displays.
For those unfamiliar with this issue, if you play back a video in the Canvas mobile app, it will not rotate into horizontal mode if you turn your phone horizontally. This makes the videos very small and hard to see on mobile. It seems like it should be a simple global fix as well, after all pretty much all other video apps I've ever seen support this.