How to reproduce:
1. Open the attached project (videoflicker.zip)
2. In the Assets, navigate to "out_60f.mp4"
3. Play the video in the Inspector, notice the fluid movement
4. In the Assets, navigate to "out_15f.mp4"
5. Play the video in the Inspector, notice the stuttering

Expected result: Both longer and shorter videos play fluidly
Actual result: The shorter video stutters once played

Reproducible with: 2017.1.0f1, 2017.1.4f1, 2017.2.3f1, 2017.4.4f1, 2018.1.2f1, 2018.2.0b5

Notes: The issue reproduces on both .webm and .mp4 formats. Playing the scenes which have a Video Player in them reproduces the issue as well. Sometimes, trying to play the shorter video throws an error: WindowsVideoMedia error 0xc00d36e5 while reading C:/projects/videoflicker/Assets/out_15f.mp4