Audacity with AAC Support on Linux

2023-12-29

UPDATE 2024-10-11: My audio workstation was recently upgraded from Linux Mint 21 to 22 (equivalent to an upgrade from Ubuntu 22.04 to 24.04).

Using the AppImage version of Audacity as per the approach described below didn't work for AAC export (couldn't find the proper lib). The solution here on how to to install Audacity with AAC export support for Ubuntu 24.04-like systems couldn't be simpler:

sudo apt install audacity

...and that's it. LOL. Below is everything that was required to get it working in Ubuntu 22.04-like systems.

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The Story

I recently had the good fortune of becoming part of the team at Radio Free Montclair (RFM) and have decided to come out of "DJ retirement" to start a new show. These days I prefer to use FOSS (Free Open Source Software) to do my internet radio DJing, and I use Mixxx for actual DJing and Audacity for post-production.

RFM uses an internet-radio-station-as-a-service platform called Radio.co under the hood. This platform accepts two file formats: MP3 and AAC. The latter is the higher quality option among the two, and being in the paradoxical postion of an audiophile internet radio DJ, my goal is to cram as much quality as possible into bitrate-limited audio streams. So, AAC is my format of choice.

However, AAC is a "non-free" (i.e. proprietary) format, so the stock Audacity available as a pre-built binary application does not include support for this format. I was able to do a custom build of some underlying software called ffmpeg to add AAC support to it, and this has allowed me to export in this format for my radio show!

Doing so turned out to be non-trivial, so I'm writing this post in the hopes that it may help you as well. Are you a technologically adventurous internet radio DJ? I encourage you to take this same approach.

I started with the official custom build instructions for Ubuntu-like systems available here and had to make a tweak based on this SO answer to enable Audacity integration.

Here are the commands as tweaked, that allowed me to successfully export AAC from Audacity on an Ubuntu-like system.

Installing Dependencies

sudo apt-get update -qq && sudo apt-get -y install \
  autoconf \
  automake \
  build-essential \
  cmake \
  git-core \
  libass-dev \
  libfreetype6-dev \
  libgnutls28-dev \
  libmp3lame-dev \
  libsdl2-dev \
  libtool \
  libva-dev \
  libvdpau-dev \
  libvorbis-dev \
  libxcb1-dev \
  libxcb-shm0-dev \
  libxcb-xfixes0-dev \
  meson \
  ninja-build \
  pkg-config \
  texinfo \
  wget \
  yasm \
  zlib1g-dev \
  libunistring-dev \ 
  libaom-dev \
  libdav1d-dev

Building ffmpeg with AAC Support

mkdir -p ~/ffmpeg_sources ~/bin && \
cd ~/ffmpeg_sources && \
wget -O ffmpeg-snapshot.tar.bz2 https://ffmpeg.org/releases/ffmpeg-snapshot.tar.bz2 && \
tar xjvf ffmpeg-snapshot.tar.bz2 && \
cd ffmpeg && \
PATH="$HOME/bin:$PATH" PKG_CONFIG_PATH="$HOME/ffmpeg_build/lib/pkgconfig" ./configure \
  --prefix="$HOME/ffmpeg_build" \
  --pkg-config-flags="--static" \
  --extra-cflags="-I$HOME/ffmpeg_build/include" \
  --extra-ldflags="-L$HOME/ffmpeg_build/lib" \
  --extra-libs="-lpthread -lm" \
  --ld="g++" \
  --bindir="$HOME/bin" \
  --enable-shared \
  --disable-static \
  --enable-gpl \
  --enable-gnutls \
  --enable-libass \
  --enable-libfdk-aac \
  --enable-libfreetype \
  --enable-libmp3lame \
  --enable-libopus \
  --enable-libdav1d \
  --enable-libvorbis \
  --enable-libvpx \
  --enable-libx264 \
  --enable-libx265 \
  --enable-nonfree && \
PATH="$HOME/bin:$PATH" make -j$(nproc) && \
make -j$(nproc) install && \
hash -r

Finishing Up

Now you have a custom ffmpeg build along with the necessary source files in your home directory.

From here, I strongly recommend using the AppImage of Audacity to get this working (available from the Audacity website linked above). Download and run the AppImage, then go to Edit>Preferences>Libraries. Here, click on the "Locate" button and it will request that you choose the location of a file associated with ffmpeg which is called libavformat.so. After doing the custom build with the tweaks described above, this file should be located at ~/ffmpeg_sources/ffmpeg/libavformat/libavformat.so so input that location, and from there AAC support should be enabled.

That about wraps it up. Happy exporting!