convert-to-mp3-mono

#!/bin/bash

FILE_REL_PATH="$1"

if [[ -z "$FILE_REL_PATH" ]]; then
  echo "audio file name required"
  exit
fi

FILE_DIR_PATH=$(dirname "$FILE_REL_PATH")
FILE_NAME_WITH_EXT=$(basename "$FILE_REL_PATH")

FILE_EXTENSION=$(echo "$FILE_NAME_WITH_EXT" | rev | cut -f 1 -d '.' | rev)
FILE_NAME_NO_EXT=$(echo "$FILE_NAME_WITH_EXT" | sed -e s/\.${FILE_EXTENSION}$//g)

TARGET_PATH="${FILE_DIR_PATH}/${FILE_NAME_NO_EXT}.mp3"

set -x
ffmpeg -i "$FILE_REL_PATH" -vn -ar 44100 -ac 1 -b:a 96k  "$TARGET_PATH"