Using the previous version of Toolbox for Mac (v3.9.1) the Record Area app would consistently record video at 30 FPS, however I've noticed that since updating Parallels Desktop to v16 and with it toolbox toolbox v4.0.0, the recordings are no longer achieving those frame rates. Most are only achieving 15 FPS with others slightly better at 16/17/19/20/24 FPS. I've since reverted back to v3.9.1 and confirmed that the recordings once again work correctly at 30 FPS. I'm running macOS Catalina v10.15.15 on a Mac Mini 2018 with an AMD Radeon Pro 580 external GPU (Blackmagic eGPU).
In addition to the above... I noticed that when exporting edited videos from DaVinci Resolve (that had been recorded using Record Area), I normally get a render speed of around 70 FPS, however I noticed earlier that it'd dropped to more like 20 FPS. Since reverting desktop and tools to the previous version the render speed from DaVinci Resolve has reverted to normal. This may be unrelated to Parallels Desktop or Tools for Mac, but I thought it worth mentioning in case there's a connection (though DaVinci Resolve hasn't been running when I've tried the previous attempts using Record Area).
Hello, The video codec from recording tools don't use fixed FPS while recording a video. Actual FPS on video depends on some conditions. For example, static/homogeneous image on screen doesn't require high FPS. It is needed to reduce resulting video file size. Moreover, FPS could be different during one recording - fast and dynamic scenes could be recorded using high FPS but static scenes with low FPS. But may be you have complains about quality of recorded video?