Yes, HandBrake can compress any 4K video to reduce video size, while converting the video format at the same time. Yes, HandBrake can rip any DVD or Blu-Ray discs that are not copy protected. HandBrake can crop and resize videos as well as restore old and low-quality videos, but for more powerful editing tools you can try DaVinci Resolve, Shotcut or VSDC Free Video Editor, which are great free options. HandBrake is a cross-platform application, available for Windows, Mac and Linux.
HandBrake is a free and open source tool for converting video from nearly any format to a selection of modern, widely supported codecs.