Linux - Convert to mp3

flac to mp3

From Ask Ubuntu

First of all you must make sure that it's installed.

sudo apt-get install libav-tools

It should have lame and flac codecs, now is just create a bash script to finish the job:

cat > flac2mp3

Here the shell will wait for your commands, copy and paste this:

#!/bin/bash
[[ $# == 0 ]] && set -- *.flac
   for f; do
  avconv -i "$f" -qscale:a 0 "${f[@]/%flac/mp3}"
done

Now press Ctrl + D. Make your script executable chmod +x flac2mp3. Now go you can use it like this:

./flac2mp3 /path/with/all/my/flacs/*.flac

You can also copy the script to somewhere in your PATH and then cd to the directory with the flacs and execute it.

---

With regards to the following parameter used above:

-qscale:a 0

will not actually give you a exact 320k file, although it is probably the best setting to use anyway. The suggested settings actually give a target bitrate of 245 kbits/s with a range of 220-260. If you really wanted 320k mp3s you would have to go to CBR and use:

-c:a libmp3lame -b:a 320k

but you would need great ears to notice the difference...

Reference:

• https://wiki.archlinux.org/index.php/Convert_Flac_to_Mp3#With_FFmpeg

m4a to mp3

Fuck me...

Copy the flac2mp3 script & just change "flac" to "m4a"

Seems to work just fine.

from StackExchange

(Doesn't actually work... but some ideas to think about in it...)

#!/bin/bash
## jc 2016
## convert [m4a mp3 wma] to mp3 128k
## [-vn] disable video recording
##
## avconv with lame mp3 plugin
## [-acodec libmp3lame]
##
## 192 k constant bitrate
## [-ab 192k]
## [-ab 128k]
##
## 44.1kHz sampling rate
## [-ar 44100]
##
## 2 channel audio
## [-ac 2]
##

##  force the shell to do a case insensitive comparison
shopt -s nocasematch

working_directory="./mp3_converted"
# check if dir exist
if [ ! -d "$working_directory" ];
then
  # dir does not exist
      echo "convert directory does not exist $working_directory..."
  `mkdir -p "$working_directory"`
       echo "convert directory created $working_directory..."
fi

COUNT=0

for i in *; do

  case $i in
    *.mp3)
      avconv -analyzeduration 999999999 -map_metadata 0 -i "$i" -vn -acodec libmp3lame -ac 2 -ab 128k -ar 44100 "$working_directory/`basename "$i" .mp3`.mp3"
      echo $i
      ;;
    *.m4a)
      ##avconv -analyzeduration 999999999 -map_metadata 0 -i "$i" -vn -acodec libmp3lame -ac 2 -ab 128k -ar 44100 "$working_directory/`basename "$i" .m4a`.mp3"
      # adjusted for ffmpeg to test.
      ffmpeg -i "$i" -n -acodec libmp3lame -ab 128k "$working_directory/`basename "$i" .m4a`.mp3"
      echo $i
      ;;
    *.wma)
      avconv -analyzeduration 999999999 -map_metadata 0 -i "$i" -vn -acodec libmp3lame -ac 2 -ab 128k -ar 44100 "$working_directory/`basename "$i" .wma`.mp3"
      echo $i
      ;;
    *)
      echo "other"
      ;;
  esac

done

## back to normal comparison
shopt -u nocasematch
exit 0