It doesn't do anything else, you have to use it alongside another buildpack thanks to the mutli-buildpack.
This buildpack provides a static build of the 2.8 version of FFmpeg downloaded from https://www.ffmpeg.org/download.html
To use this buildpack, you should prepare .buildpacks file that contains this buildpack url and your real buildpack url.
$ cat .buildpacks https://github.com/Scalingo/ffmpeg-buildpack.git https://github.com/Scalingo/go-buildpack.git
The first buildpack will install FFmpeg, the second will handle the deployment of your go application. For any other technology, go to http://doc.scalingo.com/buildpacks/
$ scalingo env-set BUILDPACK_URL=https://github.com/Scalingo/multi-buildpack.git $ git push scalingo master ...
You can verify installing ffmpeg by following command.
$ scalingo run "ffmpeg -version"
Define the following environment variable and we'll install the binary
Do it through Scalingo's dashboard or with their command line tool:
scalingo env-set WITH_FFPROBE=true
Copy the snippet above into CLI.