Join many MP3, OGG, and FLAC files into one WAV or FLAC

Question

I have 33 audio files, each about 11 seconds long, and I'd like to merge them into one lossless file. How can I do this efficiently (i.e. without cut-pasting in Audacity 33 times)?

evilsoup · Answer 1 · 2013-08-28T08:12:52.177

11

Assuming you want to merge them alphabetically, by filename:

for f in ./*.{ogg,flac,mp3}; do echo "file '$f'" >> inputs.txt; done
ffmpeg -f concat -i inputs.txt output.wav

The for loop puts all the filenames in a file called inputs.txt, one-per-line, and the second one uses ffmpeg's concat demuxer to merge the files. It is possible to use printf instead of the loop like so:

printf "file '%s'\n" ./*.{ogg,flac,mp3} > inputs.txt

Assuming a modern shell, you can also use command substitution to do the whole thing in a single line.

ffmpeg -f concat -i <(printf "file '%s'\n" ./*.{ogg,flac,mp3}) output.wav

edited Aug 28 '13 at 08:12

answered Apr 17 '13 at 15:21

evilsoup

13,097
3
59
80

1

I believe this is the 'correct' ffmepg answer as it will not re-encode anything. – Andrew Burns Aug 28 '13 at 00:59
Does not work if a file name contains `'` – Display Name Nov 11 '14 at 06:21
^ I'm talking about 1st command, didn't try other two yet. – Display Name Nov 11 '14 at 08:27
1

I get an error when I attempt the one-liner, but this works for me: `ffmpeg -f concat -safe 0 -i <(for f in ./*.flac; do echo "file '$PWD/$f'"; done) output.flac` – Peter Apr 10 '20 at 22:02
a) Edit the file inputs.txt if some files of the type (ogg,flac,mp3) do not exist. b) If 'Unsafe file name' is reported then add the following parameter : -safe 0 example : ffmpeg -f concat -safe 0 -i inputs.txt output.flac – Rudy Vissers Feb 15 '23 at 13:41
@AndrewBurns No, it will reencode. And it is good, flac needs decoding to write correct duration and md5. – Валерий Заподовников Jun 19 '23 at 13:55

Matthew Flaschen · Accepted Answer · 2010-07-31T22:30:37.677

8

You can do this with ffmpeg and sox:

for i in *.mp3 *.ogg *.flac
do
  ffmpeg -i "$i" "$i.wav"
done

sox *.wav combined.wav

edited Jul 31 '10 at 22:30

answered Jul 31 '10 at 22:20

Matthew Flaschen

2,540
1
18
27

This worked perfectly! Thank you for the help. – ashastral Aug 01 '10 at 00:11
`sox` doesn't work for OGG: `/usr/local/Cellar/sox/14.4.2_1/bin/sox FAIL formats: no handler for detected file type 'opus'` – The Onin May 07 '18 at 22:18

Raphael · Answer 3 · 2012-10-14T13:36:06.513

4

If you start with only lossless files, you can use use shntool:

shntool join *.flac

edited Oct 14 '12 at 13:36

answered Oct 14 '12 at 13:20

Raphael

425
1
4
13

I get this error: `shntool [join]: warning: unsupported format 0xfffe (Unknown) while processing file: [file1.flac]` – bonh Sep 14 '19 at 04:06

score 2 · Answer 4 · edited Mar 29 '15 at 22:25

2

However, be aware that the shntool join will insist on joining them in collating sequence (alphabetical) order EVEN IF you specify them otherwise.

shntool join fileB.flac fileA.flac

will put A before B.

You can either rename the files first or use the -r parameter ("-r ask" will prompt for the order).

Frankly I find this irritating...

Also you can force the output mode, so if you're joining FLACs:

shntool join *.flac -o flac

will result in joined.flac rather than joined.wav

edited Mar 29 '15 at 22:25

Jason Aller

2,340
6
23
21

answered Mar 29 '15 at 21:04

dgrb

21
1

`-r none` will turn off the reordering. – Tim Smith Jul 28 '23 at 07:18

score 1 · Answer 5 · answered Dec 31 '13 at 06:44

It seems that the Sound Juicer that comes with Ubuntu writes broken FLAC files, which result in no MD5 signature in the file. MAKE A COPY of the directory containing the files you want to concatenate, then run the script below.
echo fixing broken FLAC files find . -type f|grep .flac$ |while read file do flac -f --decode "$file" -o temp.wav flac -f -8 temp.wav -o "$file" done rm temp.wav

Then run
shntool join *.flac
as above.

Join many MP3, OGG, and FLAC files into one WAV or FLAC

5 Answers5

Linked