Não usei isso sozinho, mas acho que o VLC pode fazer isso.
About VLC
VLC media player is a highly portable multimedia player supporting most audio and video formats (H.264, Ogg, DivX, MKV, TS, MPEG-2, mp3, MPEG-4, aac, ...) from files, physical media (DVDs, VCD, Audio-CD), TV capture cards and many network streaming protocols.
It can also convert media files, transcode and act as a streaming server over unicast or multicast and IPv4 or IPv6. It doesn't need any external codec, program or codec pack to work.