Support for 4K video source content has become pretty standard in video editing software, but the support varies among the products. For example, some but not all of the applications can import Sony XAVC and XAVC-S formats, which are used by Sony's popular DSLRs, mirrorless cameras, camcorders, and professional video cameras. The same holds true for the H.265 High Efficiency Video Coding (HEVC) standard. Most of the applications here now can import and export HEVC, though there are still a few holdouts.
Signal Private Messenger is one of the most popular privacy chat apps. It features end-to-end encryption for all messages, voice calls, and video chats between two Signal users. It focuses a lot on individual chats. There are group chat features, but it's mostly for personal use. This is one of the biggest differences between it and rival privacy chat app Telegram. Video calls worked fine in our testing so we have no trouble recommending them. It's a neat way to get some encrypted chats as well. The app is also completely free and open source. You can't really go wrong with it, but there are better video chat apps if you need group video chats.