Conversion mp4 to mp3 in linux

A simple script to convert mp4 to mp3 on Linux.

There are two official ways of installing FFmpeg on Ubuntu: from the Ubuntu repo (v7.x) and from the snap (v4.x). Depending on your needs, you should choose the most appropriate method for you.

Requirements install:

sudo apt update
sudo apt-get install ffmpeg

Let us verify whether the installation was successful. First, test the FFmpeg version via the following command:

ffmpeg -v

Do not forget to check the available encoders and decoders. Do so by entering the following command:

ffmpeg -encoders
ffmpeg -decoders

The script that converts * .mp4 files to mp3 might look like this:

ffmpeg -i video.mp4 -f mp3 -ab 192000 -vn music.mp3

script version that converts all files from the directory:

#!/bin/bash for i in *.mp4; 
do ffmpeg -i "$i" -vn -acodec libmp3lame -ac 2 -qscale:a 4 -ar 48000 "basename "$i" .mp4.mp3";
done;

For ffmpeg with Constant Bitrate Encoding (CBR):

ffmpeg -i video.mp4 -vn -acodec libmp3lame -ac 2 -ab 160k -ar 48000 audio.mp3

Variable Bitrate Encoding (VBR)

Example to encode VBR mp3 audio with ffmpeg using the libmp3lame library:

ffmpeg -i input.wav -codec:a libmp3lame -qscale:a 2 output.mp3
ffmpeg -i video.mp4 -vn  -acodec libmp3lame -ac 2 -qscale:a 4 -ar 48000 audio.mp3

Sources and links

• https://trac.ffmpeg.org/wiki/Encode/MP3
• http://wiki.hydrogenaud.io/index.php?title=LAME#Recommended_encoder_settings
• https://trac.ffmpeg.org/wiki/Encode/MP3 how to use the external libmp3lame encoding library within ffmpeg to create MP3 audio files