I got the idea to write RetroClip after playing the game Fortnite Battle Royale and winning, and then having nothing to show for it besides a static screenshot.1 Current generation video game consoles all have a feature where you can press a button and capture the last minute or so of gameplay and I wanted this for my Mac. The key idea is that you don’t know when you want to save a video clip until after something exciting has happened, so it needs to work retroactively — it’s no good if you have to press a button to start the recording because it’s already too late.
Unlike other screen capture utilities for macOS, RetroClip does not save to an ever growing scratch file on disk as it is recording. Instead, it saves video frames to a fixed size circular buffer in main memory. The neat thing is, we don’t even need that much memory to do a good job. We can fit 30 seconds of HD video in around 40MB of memory.2 Once you see something you want to save, just press the RetroClip keyboard shortcut, and RetroClip writes the memory region with the video data out to disk, essentially instantaneously.
Anyway, you should download it and give it a try. Even if you don’t use it for games, you may find it useful for capturing those pesky bug reports where you can’t seem to reproduce it a second time. Please let us know what you think, either by email or on Twitter.