This is quite inconvenient.
2017.2.0 is unusable on Android because of this issue Unity Issue Tracker - [Android] Video playback lags when activating and deactivating Input Field
2017.2.1 patch fixed it, but now the video playback on iOS is completely broken. Just import any mp4 video, transcode it to h264 (via Unity3D import settings) and run it on any iOS device. You’ll get all sorts of skipping, audio glitches and other issues. I replicated that on an iPad 4.
Even if you won’t transcode mp4 video to h264, you’ll still get about 5 first frames skipped in the beginning of the video, and occasionally get random glitches as well.
Please advise.