IPTV is a name for a collection of technologies used to stream Television over the Internet. It can refer to live media broadcasts and video on demand services.
Differentiation and Support
Different live media transmission standards get called IPTV
- service discovery does not work at all (no support for SDP/SAP, DVB-IPTV SD&S, or others.)
- DVB-IPTV (formerly DVB-IPI)
- live media broadcasts of TV and radio can be recorded by the backend.
- broadband content guide (epg) is not implemented. FIXME, Live media broadcasts with full SI might work.
- MPEG 2 SPTS over multicast (or almost DVB-IPTV. that's usually what your ISP serves you e.g. Freebox, MPEG2 TS Multicast on MBone)
- TV and radio can be recorded by the backend.
- FIXME, Live media broadcasts with full SI might work.
- stuff thats at least somewhat close to some MPEG standard (MPEG Codecs via HTTP etc., think Shoutcast Radios)
- HTTP live streaming with MPEG 2 TS segments over HTTP is supported. Live media broadcasts can be recorded with the IPTVRecorder, on VOD services can be played with the internal player. (FIXME, how do you point the internal player to a video on demand stream?)
- Other variants with raw elementary streams over HTTP can not be recorded directly, but radio streams can be played with MythMusic. Some can be remuxed by VideoLAN on demand into SPTS and fed into the backend.
- any other media streaming via IP Networks (basically stuff that does not fit into a MPEG2 SPTS, like ShoutcastTV)
- can not be recorded directly. Some can be transcoded by VideoLAN on demand into SPTS and fed into the backend.
Currently, there are a few implementations of SAP/SDP and RTP/RTCP that can be used to emulate being on an IPTV system.
- VideoLAN, which will take any kind of stream it can open and will stream it over RTP/RTCP or RTSP. VideoLAN can be told to stream on demand so you can operate a full channel lineup without constantly consuming bandwidth to get a stream just to throw it away unwatched. Draft Guide on live-on-demand
- MumuDVB, allows you to build your own IPTV headend by converting full transports into a bunch of programs transmitted via multicast. MythTV specifics are documented in their manual.
- Austria: aonTV - IPTV service of Telekom Austria
- Australia: TPG and this useful HOWTO
- Australia: TransACT
- Canada: FIXME, see Sasktel IPTV (presumed DVB as that's what Alcatel delivers)
- France: FIXME, see FreeBox
- Germany: German ISP are required to provide public TV stations in DVB-IPTV compliant format if they want to provide them in their IPTV offering. 
- USofA: FIXME, see SureWest IPTV (MPEG2)