Comments on: How to losslessly concatenate / merge MP3 files

By: Kevin

Kevin — Sun, 17 Apr 2011 04:28:20 +0000

Thanks! This was VERY helpful for a series of large merges. Used the technique here along in a nice bash script.

By: sticks

sticks — Wed, 16 Mar 2011 21:23:35 +0000

Thanks a lot for the contribution. I’ll be sure to check it out if/when I have VBR files I need to combine.

By: human mathematics

human mathematics — Sun, 06 Feb 2011 05:03:12 +0000

Thanks very much for posting. One small change for Ubuntu Linux 10.04 ,I use id3v2 instead of id3cp — there’s no id3lib from the apt-get as far as I can tell. And I already had id3v2.

With this option it’s not automatic so there is surely something better for those who try harder.

By: svil

svil — Sun, 30 Jan 2011 13:33:14 +0000

after some looooong trial and error, found the following way to join VBR mp3s into one with _correct_ _basic_ headers/size, understood same by multiple readers (mp3info, eyeD3, mad):
$ cat infiles..* > cat.joined.mp3 #join files
$ cutmp3 -a 0:0 -b 99999:0 -i cat.joined.mp3 -O cut3.cat.joined.mp3 #clean out stuff
$ vbrfix cut3.cat.joined.mp3 -O vbr.cut3.cat.joined.mp3 #fix

u may prepend a step to remove any id3*tags, say by $ id3v2 -D infiles.. ,
and append a step to put correct id3 tags on final result

well, it depends on input materials – YMMV… Reencoding is always a final option.

here all utils i tried:

utils for info/reading:
eyeD3 files..
mp3info -x -r a infiles..

utils for joining (first 3 work ~equivalent):
cat infiles.. > result
mpgtx -j -o result infiles..
qmp3join -o result infiles.. (from quelcom package)
mp3wrap result infiles..

utils for cleanup/fix:
cutmp3 #actualy an editor but with a nifty feature to skip crap)
id3v2 -D #remove all id3* tags
ffmpeg -f mp3 -i infile -acodec copy outfile #copies too much through, put extra id3v2.4 hdr
mp3val -f #sometimes enough
vbrfix
these two were not of much use:
mp3check -B -e
checkmp3

vbrfix is from http://home.gna.org/vbrfix/ https://gna.org/svn/?group=vbrfix – compiled from source, may need fix of the input-options-checking. All else is ubuntu packages.

have fun

By: panzi

panzi — Wed, 29 Dec 2010 04:35:51 +0000

The “cat file list… | ffmpeg -f mp3 -i – -acodec copy outfile.mp3″ version does not work for me but mp3wrap works ok.

By: Lindylex

Lindylex — Sun, 09 May 2010 07:38:26 +0000

“There is another way, without going through mp3wrap.
cat file list… | ffmpeg -f mp3 -i – -acodec copy outfile.mp3
And then the id3 copy command.”

Shelby, this works perfectly no need to install unnecessary things, Thanks Lex

By: nirpius

nirpius — Tue, 23 Feb 2010 14:05:23 +0000

Just thought you may want to know you can substitute the first line of code for

mp3wrap tmp.mp3 *.mp3

to wrap all files in the folder together

By: sticks

sticks — Sat, 16 Jan 2010 22:15:35 +0000

The reason I didn’t just use cat was that, if you have ID3 tags on the beginning (v2) and/or end (v1) of your files, they will all get concatenated together amongst the mp3 frames.

This should not be noticeable in the audio playback (most players will just skip over the invalid data), and the tags don’t take up much space, so you can do it this way if you want.

But, if you’re just going to cat the files, you don’t even need the other steps! Just do “cat 1.mp3 2.mp3 > all.mp3″ like I wrote in the post, and you’re done. (As long as you have an ID3v2 tag at the beginning of file 1, it’ll still be read.)

I wanted to strip these out and end with a “clean” file in the end, which is why I went looking for mp3wrap in the first place.

The other problem with using cat is that the file duration will still be screwed up in iTunes.

By: Ron

Ron — Tue, 12 Jan 2010 05:02:37 +0000

Thanks for the info. But It seems mp3wrap has got some limit on either the number of input files or total size.

If you have wild-carded the mp3 input file list, you just be running into the shell expansion limit. If so, use the xargs trick:

$ find -name \*mp3|xargs mp3wrap all.mp3

By: Shelby

Shelby — Fri, 02 Oct 2009 16:56:15 +0000

There is another way, without going through mp3wrap.
cat file list... | ffmpeg -f mp3 -i - -acodec copy outfile.mp3
And then the id3 copy command.