#!/bin/sh
##
## SCRIPT: 00_ffmpeg_mp4_EXTRACT_AUDIO_to_mp3.sh
##
## PURPOSE: Extract the audio stream of a ('.mp4') movie file
##          into a '.mp3' audio-only file.
##
## METHOD OF USE: 
##   1) Put this script in the directory of ('.mp4') movie files
##      that you want to clip.
##   2) Edit this script to set the input & output filenames and volume level.
##   3) Run the script in a terminal window positioned at the directory
##      that holds this script and the movie files.
##
## REFERENCE:
## https://www.stellarinfo.com/article/audio-converter/convert-mp4-to-mp3.php
## (last updated Feb 2021)
##
## Example:
##
##    ffmpeg -i video.mp4 -f mp3 -ab 192000 -vn song.mp3
## where
##   'i' indicates the path to the input file.
##   'f mp3' tells FFmpeg the output file is in MP3 format.
##   'ab 192000' tells FFmpeg to encode output at 192kbps.
##   '-vn' tells FFmpeg that video is not required, extract only audio.
##
## Script started: 2021jul16
##
   
ffmpeg \
   -i input.mp4 \
   -f mp3 -ab 192000 -vn \
   output.mp3
    
##  00_temp.mp3   
 
# totem 00_temp.mp3
# ffplay 00_temp.mp3

exit