I was having all sorts of trouble trying to figure out how to extract audio from any video file into a WAV (signed 16-bit, little-endian) format. I was fortunate enough to find something that worked universally, so here it is:
if [ $# -ge 1 ]; then
if [ $# -ge 2 ]; then
ffmpeg -i "$IN" -f wav -acodec pcm_s16le "$OUT"
echo "Usage: $0 in [ out ]" >&2