Você pode usar o VLC para transmitir filmes. Do site:
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.
Além disso, em relação à velocidade do streaming, você pode ler mais aqui :
The network on which you setup the VideoLAN solution can be as small as one ethernet 10/100Mb switch or hub, and as big as the whole Internet. The VideoLAN streaming solution has full IPv6 support. Examples of needed bandwidth are:
- 0.5 to 4 Mbit/s for a MPEG-4 stream,
- 3 to 4 Mbit/s for an MPEG-2 stream read from a satellite card, a digital television card or a MPEG-2 encoding card,
- 6 to 9 Mbit/s for a DVD.