Install FFmpeg with homebrew. You'll need to install it with a couple flags for webm and the AAC audio codec.
brew install ffmpeg --with-libvpx --with-libvorbis --with-fdk-aac --with-opus
This is simple, clear and concise contract that I use for general creative and technical projects. It's based largely upon Brendan Dawe's excellent open-source design contract, but has been modified to contain more appropriate terminology for my field, and now contains sections pertaining to source code, ongoing support, NDA's etc.
Please feel free to fork, modify, distribute and use this document as you wish - and please please do use it. Do not start work without a contract, ever. Additionally: DO NOT START WORK WITHOUT A CONTRACT, EVER.
Dan Hett ("Developer", "me", "I")
[CLIENT NAME] ("Client", "you")