Audacity is looking for libavformat.55.dylib


There appears to be a problem with opening/importing QuickTime audio (m4a).


MacOS 10.14.3
Audacity 2.3.0
Build Info says:
“ffmpeg (FFmpeg Import/Export) Enabled”

How to reproduce

Download and install Audacity 2.3.0 on clean image of MacOS
Record audio using QuickTime on MacOS 10.14.3, save at m4a file.

Try to open/import an m4a file in Audacity and get:

“Error Importing
This version of Audacity was not compiled with QuickTime files support”

This alone appears to be some kind of bug/problem/inconsistency. Because it is saying one thing in Build Info and doing another.


I go to Preferences > Libraries and see:
FFmpeg Library Version: FFmpeg Library not found

I click “Locate” and it shows:
/Library/Application Support/audacity/libs/libavformat.55.dylib

I verify there is no file with that name at that location.

I downloaded the dmg and zip from

And neither contains libavformat.55.dylib

I used the locate command to search for libavformat55.dylib and it doesn’t appear to be anywhere on my filesystem.

At the moment, I am blocked from opening m4a files.

You need to install the optional FFmpeg library (be sure to get the 32-bit one the 64-bit one is for the as yet unreleased 2,3,1)

See: Installing and updating Audacity on Mac - Audacity Manual

That’s the LAME library for MP3 export - not the FFmpeg library


I appear to have just grabbed the wrong installer (64bit) and should have grabbed the 32 bit installer.

I can now open my m4a files.

Thanks for the quick reply!


we just rejigged that external site to put the 64-bit libraries at the top as we are soon to realise 2.3.1 which, on Mac, will be 64-bit (and needs the 64-biy libraries).