I want to convert all *.flac to *.mp3 in the specific folder.

This is what I've tried, but not works:

# change to the home directory
cd ~/music
# convert all *.flac files
ffmpeg -i *.flac -acodec libmp3lame *.mp3
# (optional: check whether there are any errors printed on the terminal)
sleep 60

How to get my goal?

  • 3
    did you try "FOR LOOP"? – Danila Ladner Feb 12 '14 at 15:57
  • @DanilaLadner Not yet. Thanks for the clue. – Kevin Dong Feb 12 '14 at 15:58
  • I wrote a script that does this, in parallel, and copies the tags over: http://tuxhelp.org/#flac-distiller – user136310 Sep 29 '15 at 19:38
  • Sorry I forget it. After convert file name become file.avi.mp3 you can use : rename "s/.avi//g" *.avi.mp3 for remove .avi. – user149335 Dec 29 '15 at 19:47
  • 1
    Give computer break after hard work. – MeowMeow Jul 13 '18 at 14:21

14 Answers 14


Try this:

for i in *.flac ; do 
    ffmpeg -i "$i" -acodec libmp3lame "$(basename "${i/.flac}")".mp3
    sleep 60
  • 1
    It isn't working with files containing space. How can I modify $(basename "${i/.flac}") to handle spaces? – ppr Jan 3 '16 at 15:39
  • 1
    @ppr Try putting this line just before the for loop: IFS=$'\n' – mkc Jan 3 '16 at 19:14
  • 6
    I solved the space issue by changing $(basename "${i/.flac}").mp3 to "$(basename "${i/.flac}").mp3" (putting quotes around it) – MalcolmOcean Sep 17 '16 at 20:02

A simple 1 liner solution: find -name "*.flac" -exec ffmpeg -i {} -acodec libmp3lame -ab 128k {}.mp3 \;


Note that this will be applied recursively in the given directory. I.e. if you run this from your Music folder, it will convert all flacs from subfolders and produce a .mp3 next to it. You may also do it without ffmpeg by directly using flac and lame (i.e. read w/ flac, pipe to lame, output to a file .mp3), as shown in the link.

  • You can use -maxdepth 1 I think like in X Tian's answer to limit the recursiveness. – user44370 Oct 24 '14 at 20:00
  • 2
    Yes you can. You could also use ls piped to xargs or a for loop. I'm just making the (possibly wrong) assumption that a recursive search is more along what the OP needed (i.e. change all the .flac from my music library). – Lewis Diamond Oct 24 '14 at 20:48
  • 16
    This command is great - however; You end up with files named *.flac.mp3. Using your command, I came up with this... find -name "*.flac" -exec bash -c 'ffmpeg -i "{}" -y -acodec libmp3lame -ab 128k "${0/.flac}.mp3"' {} \; – Shane Oct 27 '15 at 2:54
  • 2
    Yes, as I explained in the blog, I like this aspect of adding the .mp3 because it tells me this files comes from a lossless source, which should be found somewhere on my hard drive. – Lewis Diamond Oct 28 '15 at 16:23
  • @Shane comment worked for me. – Chaudhry Waqas Feb 19 at 9:11

If you have some white spaces in the file names:

for a in *.flac; do
  ffmpeg -i "$a" -qscale:a 0 "$f"
  • I have a folder with a mixture of mp4 and wav files. How do I convert all of them into mp3? Thank you. – kRazzy R Jun 11 '18 at 14:55

I took everything I found here (and maybe on some other sites) and created a small tool to not only create mp3s of flacs recursively, but also preserve relative paths to create them elsewhere with multithread support.

oh, and yes, I see, I didn't use ffmpeg in that case, because my OSMC didn't provide packages for ffmpeg, only avconv, but since you're already here, I guess you know, it's "basically" the same - at least for the most important part. Just replace the command "avconv" with "ffmpeg". My first runs were with the ffmpeg bin and the exact same options.

I am by no means a bash hacker, but I managed it, as my first bashscript with the given demands, and maybe someone will benefit. I am open for any suggestions from your side, but so far it works for me.

my script to spin up the 4 instances, one for each core, is like this:

# this should be quite self-explanatory 
for i in {1..4}
echo "started instance no: $i"
/home/osmc/transform.sh . &
# sleeping time can be shorter, this is just so, that 
# not all 4 processes will want to start with the same 
# file, during runtime collisions should not become an issue
sleep 5
echo "all instances started"

And the worker script like this:

# take care of spaces
# my music folders, remote is the source, local the target dir
# for all flac files start loop
for i in $(find $remote -type f -iname '*.flac' );
## this might be able to be super short with sed and complex one-liner,
## but I s*ck at regex
# strip extension
# add new extension
# get full dirname from inputfile
fulldir=$(dirname "${i}")
# strip leading dirs from full input dir
# count the dirs, add two, then you're good.
reldir="$(echo $fulldir | cut -d'/' -f5-)"
# some subdirs in my collection even have a flac subdir, you might
# ignore this, it strips only if it exists
# combine target dir and relative dir
# generate the full output filename for conversion
# create whole target directory - yes, I need it only once, but hey,
# it works, didn't want to start a if not exist statement... should I? 
mkdir -p "$outdir"
# run conversion - finally... you may want or need to replace 
# "avconv" with "ffmpeg"
avconv -n -nostats -loglevel info -i "$fullfile" -codec:a libmp3lame -qscale:a 0 "$outfile"

which can be found at https://github.com/erdnuesse/flac-to-mp3

Regards, Kay

  • welcome aboard, good effort. +1 – Alex Stragies Jan 12 '18 at 18:00

I worked on @Ketan's answer using avconv, since ffmpeg doesn't work well over here.

for i in *.flac ; do 
    avconv -i "$i" "./mp3/$i".mp3

This converts flac files in a folder into mp3 files and moves then to an existing "mp3" folder. Files will be named in the model "original_name.flac.mp3"

find . -maxdepth 1 -type f -name '*.flac' | while IFS= read -r f; do
  ffmpeg -i  "$f" -acodec libmp3lame "$( sed -e's/\.flac/.mp3/g' <<< $f )"
  • 1
    sed expression needs an ending ' – Jaime M. Aug 14 '15 at 16:15

GNU Parallel is make for these kind of tasks:

# change to the home directory
cd ~/music
# convert all *.flac files
parallel ffmpeg -i {} -acodec libmp3lame {.}.mp3 ::: *.flac
# (optional: check whether there are any errors printed on the terminal)
sleep 60

It will run the jobs in parallel (one job per cpu core) and make sure the output on the terminal is not mixed together.


Parallel FTW (no doubt you have more than one core - why not use them?):

ls *flac | while read f; do ffmpeg -i "$f" -acodec libmp3lame $f.mp3 & done

For example, if you have multiple avi files:

ls *.avi | xargs -I {} ffmpeg -i {} {}.mp3

If it can help .... I've written a small bash script to do this .... You need to have ffmpeg / flac installed.

How it works:

It takes 2 arguments :

  1. The folder of your music library (flac/ogg/mp3 ...)
  2. The destination folder (you need to create it before).

It produce :

  • An exact copy from the source folder into the destination folder, with:
    • the non flac files copied into.
    • the flac files transformed to mp3 ( VBR high quality)
  • A run.sh file with the commands to convert the flac files (this script is executed automatically).




function usage {
  echo "";
  echo "    This script convert all flac files from a folder to mp3 files to a second folder";
  echo "";
  echo "    Usage :";
  echo "        ./conv.sh {Source Folder} {Destination Folder}";
  echo "        note : booth folder must exist before starting this script";
  echo "               files other than flac are copied to the destination folder";
  echo "";

if [ ! -d "$2" ]; then
  echo "";
  echo " ERROR : [$2] is not a directory.";
  exit 1

if [ ! -d "$2" ]; then
  echo "";
  echo " ERROR : [$2] is not a directory.";
  exit 1

echo "" > run.sh
echo " convert from $FLAC_PATH to $CONV_PATH ";

find "${FLAC_PATH}" -type f |while read myFile; do
  mkdir -p "${DST_DIR}"
  # TEST if the file is a flac ....
  metaflac --show-md5sum "${myFile}" 2>/dev/null 1>/dev/null
  if [ $? -eq 0 ]; then
    echo -n "  *** $myFile [FLAC !] : "
    OUT_PATH="${DST_DIR}/$( echo $SRC_FILE | sed -e 's/.flac$/.mp3/')"

    if [ $DEBUG == 1 ]; then
      echo "  SRC = $myFile";
      echo "  OUT = $OUT_PATH"

    if [ -f "$OUT_PATH" ]; then
      echo "  exist, do nothing !";
      echo "  add to compress list !";
      echo "ffmpeg -y -i \"${myFile}\" -codec:a libmp3lame -q:a 0 -map_metadata 0 -id3v2_version 3 \"${OUT_PATH}\" " >> $COMMANDS

     echo -n "  *** $SRC_FILE  [NOT FLAC] : "
     if [ -f "${CONV_PATH}/${myFile}" ]; then
       echo " exist, do nothing !"
       echo "  copy."
       cp "${myFile}" "${CONV_PATH}/${myFile}"


echo " And now, CONVERT THE FLAC's!!! "
sh run.sh


To recursively convert in mp3 all the flac or wav files in nested folders, I used this command:

find '~/Music/' -iname '*.flac' , -iname '*.wav' -exec bash -c 'D=$(dirname "{}"); B=$(basename "{}"); mkdir "$D/mp3/"; ffmpeg -i "{}" -ab 320k -map_metadata 0 -id3v2_version 3 -acodec libmp3lame "$D/mp3/${B%.*}.mp3"' \;

It will create a folder named "mp3" inside the one with flac or wav files and, inside the mp3 folder, it will save relative mp3 files with a bitrate of 320kbps, without keeping the old file extension in the name.


The file name is "wav2mp3"

# put the script to /usr/local/sbin

if [ "${EXT_IN}" = "" -o "${QUALITY}" = "" ]; then
    printf "Usage: wav2mp3 \<in_file_ext\> \<quality\> \ne.g. wav2mp3 wav 2\n"
    exit 1

#String delimeter
# List of the files in directory lower than current to array
FILES_LIST=`find . -type f  -name "*.${EXT_IN}"`
for FILE in ${FILES_LIST}; do
    echo $FILE
    PREFIX=`echo $FILE | awk -F \. 'OFS="."{ $NF="" }1' | sed 's/.$//'`
    echo $PREFIX
    ffmpeg -i $FILE -codec:a libmp3lame -qscale:a $QUALITY $PREFIX.mp3
  • Consider using shellcheck.net. It has quite a few suggestions regarding your script. – llogan Mar 29 at 17:47

for a in *.flac

do OUTF=echo "$a" | sed s/\.flac$/.mp3/g

ffmpeg -i "$a" -acodec libmp3lame "$OUTF"


  • 2
    welcome to U&L, your answer hardly add anything to @Ketan accepted answer four years ago. – Archemar Dec 29 '17 at 8:45

I realize this comes quite late, but for memory, see my script "batchaudiocvt" on sourceforge. It is a (quite large) shell script designed for efficient mass conversion of audio files, between many formats. In particular, it makes its best to convert the usual tags.

  • This question is about how to handle the loop in the shell. The user already knows the command they want to use to do the conversion. – G-Man Oct 31 '18 at 23:51
  • Welcome to Stack Exchange.  Are you Eric Dujardin?  If so, it would be good to use the contact form and select ‘‘I need to merge user profiles’’ to have your accounts merged. – Scott Nov 1 '18 at 2:19
  • Sorry, I was just trying to help with the stated goal of converting the files. Anyway the provided script may be worth a read. – Eric Dujardin Nov 1 '18 at 8:18

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