Although I was warned by Hype 3 Pro that Firefox 35 and below needs ogg-Files, my Firefox 34 plays the mp3-file I embedded in a document without problems. So, since which version does Firefox play mp3-files, actually?
This is an update we need to make to our browser compatibility warnings (and docs) -- MP3s work fine in Firefox. (See clarification below from @JimScott)
Edit: Documentation has been updated.
From the Mozilla site:
To avoid patent issues, support for MP3 is not built directly into Firefox. Instead it relies on support from the OS. Firefox supports this format on the following platforms: Windows Vista+ since Firefox 22.0, Android since Firefox 20.0, Firefox OS since Firefox 15.0, Linux since Firefox 26.0 (relies on GStreamer codecs) and OS X 10.7 since Firefox 35.0.
Cool, fine, thanks for the fast reply.