Tahrpup 6.0 is a Puppy Linux that is based on Ubuntu 14.04 LTS Trusty Tahr. Accordingly, it supports use of Ubuntu packages. According to every guide I can find on this, Firefox needs two packages to get H.264 support in Ubuntu: gstreamer1.0-plugins-good and gstreamer1.0-libav. I have installed both of these, with all dependencies, and I still have no H.264 support. I do notice there is no --enable-gstreamer=1.0 option in about:build-config. But I am running the official 34.0.5 tar-ball from Mozilla (https://download.mozilla.org/?product=firefox-34.0.5-SSL&os=linux&lang=en-US). Does that mean I need to use gstreamer-0.10, which means finding gstreamer-0.10-ffmpeg, which is no longer in the default repositories?' (There is no --enable-gstreamer option at all, in fact.) It'd be a whole lot easier if I could just have embedded HTML5 load in the vlc plugin. VLC and it's plugin handle H.254 out of the box.