FaceFX 2009 introduced .facefx and .animset file formats. Legacy versions of FaceFX used the FXA, FXS, FXA, and FXM files instead. See below for a comparison.
.facefx files are a combined FXA & FXS file.
.animsets are a combined FXE and FXM file.
FXA/FXS and FXE/FXM files must be converted using the File->Import option.
.facefx and .animset files contain editor-only data and in-game data.
.facefx and .animset files can be published to create .facefx_ingame and .animset_ingame files.
Audio data is no longer stored.
Audio paths are stored relative to the path stored in the facefx.clientspec file in the FaceFX install directory.
FaceFX Studio must be restarted after the facefx.clientspec file is modified.
We recommend using your source control root directory (ex: C:\Perforce or D:\Depot) as your FaceFX root directory. That way, all of your FaceFX assets are grouped in directories under the FaceFX root, and actors are easily transported between different artists, without the bulk of carrying the audio in the session file.
Since audio data is no longer stored it will be resampled if needed every time it is loaded. For short or normal length audio this is quite fast, but for larger audio lengths or songs this can mean a few seconds of waiting when you select the animation. To get around this you can resample the audio and save it to disk. If you would prefer not to alter that audio (for example if it points to the actual in-game audio) you can use the Python callback system to register a preloadaudio callback to intercept the audio load and redirect it somewhere else (for example, to the resampled version in a different directory or on a different disk).