If it seems like raw video:

ffplay -f mulaw -ar 8000 -i multimovies.ul (adjust sample rate — 8 kHz is common for μ-law)

If it’s μ-law audio:

Multimovies.ul

If it seems like raw video:

ffplay -f mulaw -ar 8000 -i multimovies.ul (adjust sample rate — 8 kHz is common for μ-law) multimovies.ul

If it’s μ-law audio: