easy way to join a series of mp3 files and insert a 4 sec silence

[perfection]

I have a series of mp3 files which i would like to stitch together but seperate each with a 4 sec silence....any software that can do this or will it have to be copy paste and mannually add the silence on a timeline?

[hello_hello]

You can do it without re-encoding with MP3DirectCut. You can run more than one instance of MP3DirectCut, each with a different MP3 open, and select the MP3s in each and copy and paste between MP3DirectCut instances. If it can't add silence for you (I can't remember) you can always create a 4 sec silent MP3 yourself and open it for copying and pasting too. Alternatively you can open an existing MP3, cut it down to 4 seconds long and reduce it's volume to silence.

For variable bitrate MP3s, I don't think you can count on the timeline being accurate, but if all you need to do is join existing MP3s while inserting silence in between, that shouldn't matter.

[perfection]

Thank you

[jagabo]

With ffmpeg:

Create a text file called list.txt with the name of each file in the order you want them appended:

file 'first.mp3'
file 'silence.mp3'
file 'second.mp3'
file 'silence.mp3'
file 'third.mp3'

and then use a command line like:

ffmpeg -f concat -i list.txt -c copy output.mp3