It worked, I've managed to extract the .PSS files into 2 streams.
One being .ss2, and the other one, well, it's some kind of 'Movie Clip' type of file, and I'm unable to play that movie clip file by double clicking on it.
In VGMToolbox go to VGMToolbox -> Misc. Tools -> Stream Tools -> Video Demultiplexer -> Format: PSS
Then drag-n-drop PSS files into the large empty area.
If that doesn't work directly on the original PSS file, try dropping in the 2 resulting PSS files you mentioned.
Note that PSS may sometimes have non-standard audio (e.g. Zone of the Enders), and worst case requires a specialized demuxer. It helps if we know the game.
edited 4:46 PM EST January 10, 2022
by Jack Krowell at 2:01 AM EST on January 12, 2022
The game is Twisted Metal: Black, and I merely wanted the audio file over the video file rather.