TheSwissKnife/xbmc — comment on commit 1b1c0bb122b2106111d09206f917b5a6625881c4
File: xbmc/cores/dvdplayer/DVDCodecs/Video/DVDVideoCodecFFmpeg.cpp line 1012
By FernetMenta:

I think a avcodec_close and avcodec_open should do but this is just guessing. avcodec_open need a pointer to the AVCodec whicht I think is stored in m_pCodecContext.

Calling CDVDVideoCodecFFmpeg::Dispose and creating a new decoder through CodecFactory will open a new instance of vdpau.