Yet Another Input File Editor (Yaife) is, you guessed it, an editor for TAS movie files. I know these already exist (hence the name), but reading about the problems people have with editing BizHawk movie files (unzipping, finicky sync settings) and having my own troubles with HourGlass, I decided the idea could use an update.
Currently supported movie files are: BizHawk (BK2), Hourglass, Dolphin, Visual Boy Advance, PSXjin and PCSX-rr.