True, but that was biased and unfair. Some developers leveraged their Debian influence to get Debian to switch from ffmpeg to libav, but the technical merits were debatable. In the end, they came back to ffmpeg.
This is mostly a political issue. Software-wise AFAIK ffmpeg has been integrating many changes from libav but the opposite is not true, making IMHO ffmpeg the right choice.
Good article (2012) with in-depth history: http://blog.pkh.me/p/13-the-ffmpeg-libav-situation.html
More recent (2015) short take on the matter, seems pretty biased though: https://github.com/mpv-player/mpv/wiki/FFmpeg-versus-Libav
Wikipedia entry: https://en.wikipedia.org/wiki/Libav#Fork_from_FFmpeg
The github link is on mpv wiki. mpv is a descendant of mplayer and mplayer2 (the latter being mostly dead). IMHO mpv is the best media player for any OS (lightweight, snappy, reads everything, better options and CLI than mplayer*, etc.).