Apple just suggested to IETF (Internet Engineering Task Force) the HTTP Streaming to replace the RTSP (Real Time Streaming Protocol) and even Flash and Silverlight.
The purpose of this protocol is simple: allow audio and video streaming from a HTTP server using today's codecs (MPEG2, H.264, AAC & MP3). The idea is not new as Apple is talking about it since iPhone OS 3.0 & Quicktime X, however in order to really implement
it Apple just submitted all the necessary documents to IETF, hoping for it to become a standard.
Using what already works
Apple hopes to replace RTSP developped by Real and Netscape in the late 90s. We have to acknowledge that there are several bugs inherent to this format, like the usage of a dedicated port (554 by default), which is often closed by routers and firewalls and
the average user might not be able to open easily.
The usage of HTTP Streaming would allow to use the regular internet port (80 or 443). The idea of HTTP Streaming is simple, split a video file in 10 seconds blocks for example. The audio and video players use a playlist file .m3u8 to know what file and where
to download. The player just has to search and aggregate the blocks in the order given by the playlist which is also giving updates to the player to let it know if new files are available, in case of a live broadcast.
The user can start playing the audio or video file while downloading the blocks. The last block contains a tag to let the player know the streaming is over.
The playlist allows to use several servers simultaneously and can change the type of file depending on the network (3G, Edge...) and thus adjust the quality.
An open source technology for everyone to replace flash and silverlight
The big asset of this technology is that is can work with any player and a regular MPEG2 encoder can create a stream for this type of platform.
Apple hopes, with this technology, to make people forget that the iPhone is not Flash or Silverlight compatible. Now time will tell if this new solution will be successful, but on the paper it really seems to have taken a good start.