converting m4a to mp3

mmatt · 11-27-2007, 09:56 AM

Wow, I didn't realise this thread was still active. Back when it started I'm not sure there were any tools to do this easily, hence the scripts.

Out of interest, do those tools transfer the tags as well as the data? And will they cope with badly formed tag fields?

hoodooman · 11-28-2007, 03:22 AM

As far as I know ecasound doesnt copy the tags over.It may well do if you looked at the man for it but as I only use it sometimes this isnt a problem for me.It would be a perfect app if it did that too.

mmatt · 11-28-2007, 09:42 AM

I see. Handy tool for the occasional file or two then, I'll remember that.

For the benefit of future readers then, If you want to convert you're entire (for example iTunes) music collection from m4a to mp3, keeping all the tags, you may still need to do it the hard way. Or should I say less convenient way; it's not really hard, especially as there are now two or three different scripts to choose from in this thread.

Enjoy your music.

nobodysbusiness · 01-16-2008, 09:29 PM

I just wrote a program to convert M4As to MP3s, transferring the artist, album, song name and track number tags. It's available here. Drop a comment if it breaks or there are some tags you want that aren't transferred.

akamikeym · 05-15-2008, 07:24 AM

Hi,

I've taken the scripts from this post and changed the user interface a little to work in what I would consider a more acceptable manner.

It takes a list of m4a files (including wildcards) and converts them into mp3's and dumps them in the working directory.

Code:

#!/bin/bash
#
# Dump m4a to mp3

if [ "$#" -eq "0" ] ; then
        echo "Usage: '$0 filenames'"
        exit 1
fi
for i in "$@"
do
	echo Editing file - $i

	if [ -f "$i" ]; then
		faad "$i"
		# Get the source wav file produced by faad
		x=`echo "$i"|sed -e 's/.m4a/.wav/'`
		# Get the destination filename including path
		y=`echo "$i"|sed -e 's/.m4a/.mp3/'`
		# Strip pathso it's put in the current directory
		y=`echo ${y##*/}`
		# Get the track info
		faad -i "$i" 2>.trackinfo.txt
		title=`grep 'title: ' .trackinfo.txt|sed -e 's/title: //'`
		artist=`grep 'artist: ' .trackinfo.txt|sed -e 's/artist: //'`
		album=`grep 'album: ' .trackinfo.txt|sed -e 's/album: //'`
		genre=`grep 'genre:*/ ' .trackinfo.txt|sed -e 's/genre: //'`
		track=`grep 'track: ' .trackinfo.txt|sed -e 's/track: //'`
		year=`grep 'year: ' .trackinfo.txt|sed -e 's/year: //'`
		# Convert the file using lame
		lame --alt-preset 160 --tt "$title" --ta "$artist" --tl "$album" --tg "$genre" --tn "$track" --ty "$year" "$x" "$y"
		# Remove temporary files
		rm .trackinfo.txt
		rm "$x"
	fi
done

Steel_J · 05-15-2008, 01:52 PM

Thank will try it

kah00na · 08-07-2008, 03:29 PM

Instead of removing the m4a files or just leaving them, they could just as easily be moved to the trash. If the file does get hosed up, you could still retrieve it from the trash. Here's the command - just remove the "rm $x" or whatever variable name you end up using.

Code:

mv "$i" ~/.local/share/Trash/files

I modified my script to do this and it sure is nice to not to actually lose the m4a files. Just remember to empty your trash occasionally!

kah00na · 08-07-2008, 03:31 PM

Heres that last script updated to move the m4a files to the trash:

Code:

#!/bin/bash
#
# Dump m4a to mp3

if [ "$#" -eq "0" ] ; then
        echo "Usage: '$0 filenames'"
        exit 1
fi
for i in "$@"
do
	echo Editing file - $i

	if [ -f "$i" ]; then
		faad "$i"
		# Get the source wav file produced by faad
		x=`echo "$i"|sed -e 's/.m4a/.wav/'`
		# Get the destination filename including path
		y=`echo "$i"|sed -e 's/.m4a/.mp3/'`
		# Strip pathso it's put in the current directory
		y=`echo ${y##*/}`
		# Get the track info
		faad -i "$i" 2>.trackinfo.txt
		title=`grep 'title: ' .trackinfo.txt|sed -e 's/title: //'`
		artist=`grep 'artist: ' .trackinfo.txt|sed -e 's/artist: //'`
		album=`grep 'album: ' .trackinfo.txt|sed -e 's/album: //'`
		genre=`grep 'genre:*/ ' .trackinfo.txt|sed -e 's/genre: //'`
		track=`grep 'track: ' .trackinfo.txt|sed -e 's/track: //'`
		year=`grep 'year: ' .trackinfo.txt|sed -e 's/year: //'`
		# Convert the file using lame
		lame --alt-preset 160 --tt "$title" --ta "$artist" --tl "$album" --tg "$genre" --tn "$track" --ty "$year" "$x" "$y"
		# Remove temporary files
		rm .trackinfo.txt
		rm "$x"
		mv "$i" ~/.local/share/Trash/files
	fi
done

kah00na · 08-07-2008, 03:35 PM

Also, since this script is reading files as arguments, you can add a link to your ~/.gnome2/nautilus-scripts directory then when you right click a file, under "Scripts" will be your script. You can then click on it and it will do the conversion without having to open a terminal window. There won't be any progress information, but you can just watch for your CPU to drop off. Here's the command to make the link:

Code:

ln -s /path/to/your/script ~/.gnome2/nautilus-scripts

This right-click menu has saved me a lot of time.

slopshid · 10-19-2008, 01:33 PM

If anyone's interested at all - instead of having to explicitly use sed to strip the extraneous extensions from the mp3, you can use ${i%.m4a}.wav, etc.:

Code:

#!/bin/bash
#
# Dump m4a to mp3

if [ "$#" -eq "0" ] ; then
        echo "Usage: '$0 filenames'"
        exit 1
fi
for i in "$@"
do
	echo Editing file - $i

	if [ -f "$i" ]; then
		faad "${i%.m4a}.wav"
		# Get the source wav file produced by faad
		x=`echo "${i%.m4a}.wav"
		# Get the destination filename including path
		y=`echo "${i%.m4a}.mp3"
		# Strip pathso it's put in the current directory
		y=`echo ${y##*/}`
		# Get the track info
		faad -i "$i" 2>.trackinfo.txt
		title=`grep 'title: ' .trackinfo.txt|sed -e 's/title: //'`
		artist=`grep 'artist: ' .trackinfo.txt|sed -e 's/artist: //'`
		album=`grep 'album: ' .trackinfo.txt|sed -e 's/album: //'`
		genre=`grep 'genre:*/ ' .trackinfo.txt|sed -e 's/genre: //'`
		track=`grep 'track: ' .trackinfo.txt|sed -e 's/track: //'`
		year=`grep 'year: ' .trackinfo.txt|sed -e 's/year: //'`
		# Convert the file using lame
		lame --alt-preset 160 --tt "$title" --ta "$artist" --tl "$album" --tg "$genre" --tn "$track" --ty "$year" "$x" "$y"
		# Remove temporary files
		rm .trackinfo.txt
		rm "$x"
		mv "$i" ~/.local/share/Trash/files
	fi
done

rocksniffer · 12-12-2008, 08:49 PM

p0g0, that script of yours is the only one I could get to work and it works great!

elektronaut · 05-10-2009, 10:01 AM

I found a way to convert ALL m4a's in my music collection recursively. Haven't been looking at this thread for a while, there's another suggestion to do the recursion, but mine gives you the opportunity to check if everything went well. There are two parts, first the script for recursively working in all directories with m4a files inside, then the conversion script which is mostly the same as the one on http://wiki.linuxquestions.org/wiki/.m4a_to_.ogg

For the recursion and logfiles:

Code:

#!/bin/bash
# m4a2ogg_r.sh
# converts m4a audio files to ogg files recursively

INPUTFILES=~/m4a2ogg_in.txt
EXPECTED_OUT=~/m4a2ogg_exp.txt
OUTPUTFILES=~/m4a2ogg_out.txt
DIFFRESULT=~/m4a2ogg_diff.txt
TEMP=~/m4a2ogg.tmp
find . -type f -iname '*.m4a' | sed "s+\.+$PWD+" > "$INPUTFILES"
cat "$INPUTFILES" | sed -e 's/.m4a/.ogg/' > "$EXPECTED_OUT"
if [ -f "$OUTPUTFILES" ]
then
  rm "$OUTPUTFILES"
fi
touch "$OUTPUTFILES"
LASTDIR=""
while read LINE ;
do
  DIRNAME=`dirname "${LINE}"`
  if [ "${DIRNAME}" != "${LASTDIR}" ]
  then
    cd "${DIRNAME}"
     m4a2ogg | grep 'encoded' | sed "s;encoded ;${DIRNAME}/;" >> "$OUTPUTFILES"
  fi
  LASTDIR="${DIRNAME}"
done < $INPUTFILES
cat "$EXPECTED_OUT" | sort > "$TEMP" && mv "$TEMP" "$EXPECTED_OUT"
cat "$OUTPUTFILES" | sort > "$TEMP" && mv "$TEMP" "$OUTPUTFILES"
diff "$EXPECTED_OUT" "$OUTPUTFILES" > "$DIFFRESULT"
exit 0

My adaption of the conversion script, successful output is now echoed to stdout so that it can be used for the logging files.

Code:

#!/bin/bash
#
# m4a2ogg, converts m4a files to ogg files
# based on http://wiki.linuxquestions.org/wiki/.m4a_to_.ogg
# see also http://www.linuxquestions.org/questions/linux-general-1/converting-m4a-to-mp3-170553/

for i in *.m4a; do
   tmp=$(mktemp)
   y=`echo "$i"|sed -e 's/.m4a/.ogg/'`
   faad -i "$i" 1>/dev/null 2>"$tmp"
   if [ $? -ne 0 ] ; then
       rm "$tmp"
       echo "failed to get information from $i"
       continue
   fi
   title=`grep 'title: ' "$tmp"|sed -e 's/title: //'`
   artist=`grep 'artist: ' "$tmp"|sed -e 's/artist: //'`
   album=`grep 'album: ' "$tmp"|sed -e 's/album: //'`
   genre=`grep 'genre: ' "$tmp"|sed -e 's/genre: //'`
   track=`grep 'track: ' "$tmp"|sed -e 's/track: //'`
   year=`grep 'year: ' "$tmp"|sed -e 's/date: //'`
   faad "$i" -o - | oggenc -q 5 -t "$title" -a "$artist" -l "$album" -G "$genre" -N "$track" -d "$year" -o "$y" -
   if [ $? -ne 0 ] ; then
       echo "failed to encode $i"
   else
       echo "encoded $y"
   fi
   rm "$tmp"
done

After checking that everything went well, you can delete the m4a files with a little script (or you choose the other solution of moving them into Trash, given a few posts earlier):

Code:

#!/bin/bash
# this deletes all files whose paths occur 
# in the text file given as the parameter

while read LINE ;
do
  rm "$LINE"
done < $1
exit 0

After all this I found out that soundKonverter exists. Well, now I can do this on the command line and have exercised again a bit in shell scripting...

Steel_J · 05-11-2009, 12:09 PM

Wow, I first posted a script version to this thread 3 years ago, hahaha!

Cool!

Glad to see the scripts evolving. I'll try this last one.

IpV8 · 10-23-2010, 08:13 PM

Did anyone else notice that all these methods GREATLY reduce the sound quality of the files? Maybe I just have picky ears, but I find it rather frustrating that there isn't a way to convert m4a's without loss of quality.

Steel_J · 10-23-2010, 09:09 PM

Any conversion reduces quality my friend. It is a price you chose to pay for getting out of proprietary formats.