In common with most Linux distros, Intel’s ClearLinux doesn’t ship H.264 decoding by default. Given the novel nature of ClearLinux there isn’t a nice off the shelf solution to this yet, so we have to use a workaround. I’ll try and find a better way to achieve this, but for now this will get H.264 video working in YouTube / Twitter etc, for now:

tar xf ffmpeg-snapshot.tar.tz2
cd ffmpeg-snapshot
./configure --prefix=/usr/local --enable-shared
sudo make install
sudo sh -c 'echo /usr/local/lib >> /etc/
sudo ldconfig
echo "export LD_LIBRARY_PATH=/usr/local/lib" >> ${HOME}/.config/firefox.conf