Run the .pkg file. If the process seems to stall on "Validating packages," be patient—it is a known quirk that usually resolves itself.
Download the FFmpeg .pkg installer from the Buanzo site. ffmpeg library audacity download
The easiest way to get the library is by using the recommended automated installers. Run the
Import and export high-quality formats like M4A (used by iTunes/iPhone), WMA , and AC3 . and AC3 .