Original URL: http://www.theregister.co.uk/2012/09/19/miracast/
Hello Miracast vid-beaming: ANOTHER thing the iPhone 5 hasn't got
Shiver me timbers, 'tis on the Galaxy SIII though
The Wi-Fi Alliance has formally launched Miracast, the 5GHz peer-to-peer wireless connection for echoing a phone onto a TV, with a test suite and the first devices supporting the protocol.
Those devices are the Samsung Galaxy SIII and Echo-P Series TVs, with support promised for the Note range of tablets. Less-specific messages of support have come from Sony, LG, Intel and a host of other silicon manufacturers who reckon Miracast will be the next big thing in Wi-Fi.
Miracast uses the existing 2.4GHz Wi-Fi connection to negotiate a 5GHz Wi-Fi Direct connection specifically for the streaming of video. Chip makers have talked about background streaming, but the killer application is replicating the tablet/phone display on a big screen without all that mucking about with codecs and DRM which DLNA involves (though without the quality too).
DLNA also uses the existing IP network to negotiate use of a big screen, but it also offloads decoding of the video stream to that device, which can be an advantage - the big screen may be better at rendering video than the phone - however it also limits the technique to content both devices can decode, and content which isn't protected by rights management locked to a specific device.
Miracast, in contrast, is effectively a wireless HDMI cable, copying everything from one screen to another using the H.264 codec and its own DRM layer emulating the HDMI system. The Wi-Fi Alliance suggests Miracast could also be used by a set-top box wanting to stream content to a TV, or tablet, but the killer app is replication.
When DLNA works it is top: being able to throw a YouTube clip to the living-room TV and see the quality improve is like science fiction to most of us, but if TV and/or content refuse to play nicely then it all breaks down. Miracast is hoping to capitalise on that failure by reducing the intelligence required of the display, using standard Wi-Fi communications and separating devices into "Source" and "Display" categories.
Wi-Fi Direct, the peer-to-peer protocol used by Miracast, has been almost entirely ignored by the world despite backers (primarily Intel) pushing it as the next evolution of Wi-Fi. The standard allows a device to maintain multiple wi-fi connections, and has been touted as the ideal tech of mice, keyboards and all sorts of unlikely things, but so far adoption has been very slow. Miracast could be the killer app for Wi-Fi Direct, if the DLNA team doesn't get its act together first. ®