A month ago, OnePlus promised to enable EIS for 4K video recording on the OnePlus 5 and here it is - OxygenOS 4.5.7 brings the additional stabilization, along with some other changes. EIS (Electronic Image Stabilization) works in conjunction with OIS (a hardware stabilization) for an even smoother footage. Still, it requires a lot of computing power, which is why many phones put an upper limit of 1080p/30fps. The Snapdragon 835 has enough grunt to pull it off, though. The rest of the changelog includes Wi-Fi connectivity improvements (again) and standby battery enhancements (it doesn't...
Source: http://www.gsmarena.com/oneplus_5_gets_eis_for_4k_videos_in_latest_update-news-26512.php
