Problems exporting sections of a long .mp3

I have a .M4A audio book that I need to make playable on a car MP3 CD player. It is a long audiobook, 33 hours long.

If I convert the .m4a file to .mp3 it loses all its chapter headings, which is the only way to properly navigate the thing. I have therefore decided to export the sections as seperate .mp3 files with the timecodes I can get from the original .m4a.

All goes well for the first few chapters. However, when I enter the timestamps 57m to 1h 25m and click “Export Selected Audio” the timestamps change to 00:00:00 and 33:46:29 those being the stand and end of the audiobook.

Cutting and pasting or whatever gets me the same results. It just doesn’t seem to want to select anything past about an hour. I can listen past an hour within audacity without issue, but the sound visualisation does appear to be messed up, with big hour long sections showing no spikes where there is clear speaking to be heard.

Is there a way around this, or is there another way to get the results i’m looking for?


Where did you get the .m4a from?


A friend supplied it.

I managed to solve the issue by using a program called mp3splt, so apparently it can be done. I suppose very long/big audio files aren’t audacity’s strong point?

I suppose very long/big audio files aren’t audacity’s strong point?

It’s not a surveillance recorder, no. Audacity a couple of versions ago would not go over 13 hours.

Another note. Audacity internally works uncompressed at super high quality. So even though you supplied a nice but hefty m4a file, inside Audacity that’s going to balloon to many multiple GB.

MP3Split doesn’t do that. It only works on the signals that are there. The shortcoming of that is an inability to apply effects and filters. Pretty much all you can do is cut or “Split.”


Are you using Audacity 2.1.2 from