ffmpeg build is a custom vulcan build downloaded from (http://bruchu.github.io/heroku-binaries/ffmpeg.tar.gz) and also contains ffmpegthumbnailer
It doesn't do anything else, so to actually compile your app you should use heroku-buildpack-multi to combine it with a real buildpack.
To use this buildpack, you should prepare .buildpacks file that contains this buildpack url and your real buildpack url.
$ ls .buildpacks ... $ cat .buildpacks https://github.com/bruchu/heroku-buildpack-ffmpeg https://github.com/heroku/heroku-buildpack-play $ heroku create --buildpack https://github.com/ddollar/heroku-buildpack-multi $ git push heroku master ...
You can verify installing ffmpeg by following command.
$ heroku run "ffmpeg -version"
$ heroku run 'ffmpegthumbnailer -v'
Copy the snippet above into CLI.