theora_derf.ogg has been encoded with derf's theora encoder, written from scratch, which will replace the current, still vp3-based xiph theora reference encoder in contrary to the vp3-based theora encoder it supports all theora features, even those which are not covered by vp3 but have been added to the theora specs for extending its capabilities. the stream shows that libavcodec's internal theora decoding isnt able to decode theora streams going beyond the vp3 format's limits b-o-n-d AT gmx DOT net