64-bit LAME for Mac OS The optional FFmpeg library allows Audacity to import and export a much larger range of audio formats including M4A (AAC), AC3, AMR (narrow band) and WMA and also to import audio from most video files Audacity FFMpeg codec install for Mac OS - YouTub pkg installer versions (ZIP version is provided as alternative, PKG is better than DMG). Audacity 2.3.1 on Mac is now a 64-bit application and thus requires 64-bit libraries for LAME and Ffmpeg. 64-bit libraries for Audacity 2.3.1 and later. It will allow you to open m4a audio files FFmpeg and LAME on macOS / Mac OS X. This vides explains how to install the FFMpeg codec library to Audacity. Drag the Audacity.app icon in the DMG window to the /Applications folder icon on the right Audacity FFMpeg codec install for Mac OS - YouTube. Double-click the downloaded DMG to mount it.
If you use the optional FFmpeg library you will need to download the 64-bit versions of it. Audacity 3.0.2 for macOS is now a 64-bit application.
