I've searched and searched, but I can't find anything, besides compiling it, which gives me an error about ASM.
You can install avconv with package libav-tools
sudo apt-get install libav-tools
Unfortunately, those answer won't work on Bionic version because FFmpeg won't include the avahi libraries in the package. you will have to install libav-tools manually in order to get avconv_cli
sudo apt install ffmpeg #requirement to run avahi wget http://launchpadlibrarian.net/348889634/libav-tools_3.4.1-1_all.deb sudo dpkg -i libav-tools_3.4.1-1_all.deb
I'm adding this answer here because this topic looks like the only one discusses the avconv but the answers are not for the later versions of Ubuntu distro. But why would you if you could get the same result from ffmpeg.