FFmpeg package for Apple Silicon

You can compile ffmpeg for Apple Silicon by yourself. For this you will need Xcode, which comes with all the necessary tools.

You can download Xcode from the App Store, from Apple's website, or install the Xcode command line tools running xcode-select --install on the Terminal app.

After getting Xcode, you need to open it once to accept the terms and set up everything. You will be asked for your computer password.

After setting up Xcode, execute the following commands in that order, on the Terminal app, as a normal user (root is not necessary and not recommended). Lines beginning with # are comments and you should not execute them on the terminal.

# Create and go to a folder where you'll save the ffmpeg source code
mkdir -p /opt/local/src
cd /opt/local/src

# get the ffmpeg source code from the official source
git clone https://git.ffmpeg.org/ffmpeg.git ffmpeg
cd ffmpeg

# set up build and begin to compile
./configure --prefix=/opt/local
make install

# check that your compiled version of ffmpeg has arm64 (Apple Silicon) architecture
/opt/local/bin/ffmpeg -version

Looks like there's a working script and a built version now available at https://www.osxexperts.net