If it seems like raw video:
file multimovies.ul This checks magic bytes. Might say "data", "RIFF", "ISO Media", or "μ-law audio". multimovies.ul
If it’s μ-law audio:
ffplay -f mulaw -ar 8000 -i multimovies.ul (adjust sample rate — 8 kHz is common for μ-law) If it seems like raw video: file multimovies
hexdump -C multimovies.ul | head -n 10 Look for headers like ftyp (MP4), RIFF (AVI/WAV), OggS , MKA , or plaintext strings. or plaintext strings.