Open or not open, that is the stupid question.

When you install Google Chrome on Ubuntu 12.04, you might not watch mp4 video by Chrome, that's because you didn't install mpeg codec. (Ex. The online courses of Coursera) You could install ffmpeg-extra for chromium by apt-get command like below: $ sudo apt-get -y install chromium-codecs-ffmpeg-extra $ Wish this helps. regards, Stanley Huang

If you want to modify mp3 in Ubuntu, you could use "audacity". And you could download it from reposity. The commands as the following. # apt-cache search audacity create-resources - shared resources for use by creative applications audacity - fast, cross-platform audio editor audacity-data - fast, cross-platform audio editor (data) audacity-dbg - fast, cross-platform audio editor (debug) vamp-plugin-sdk - audio analysis and feature extraction plugins (SDK) # apt-get -y install audacity After for a while, I heard a good tool to convert mp4 to mp3 call avidemux # apt-cache search avidemux libavidemux0 - a free video editor - shared libraries avidemux - a free video editor - GTK version avidemux-cli - a free video editor - command line version avidemux-common - a free video editor - Internationalization files avidemux-plugins-cli - a free video editor - CLI plugins avidemux-plugins-common - a free video editor - common files for plugins avidemux-plugins-gtk - a free video ...