Miracast

Miracast is a peer-to-peer wireless screencast standard created by the Wi-Fi Alliance. Billed as an open alternative to Apple’s AirPlay Mirroring, it allows users to, for example, echo display from a phone made by Company A onto a TV made by Company B, share a laptop screen with the conference room projector in real-time, and watch live programs from a home cable box on a tablet. Miracast connections are formed via Wi-Fi Direct, which allows direct Wi-Fi connections in a similar manner to bluetooth.[1][2][3][4][5] Miracast only works over Wi-Fi. It cannot be used to stream to a router access point. On 29 October 2012, Google announced that Android version 4.2 (updated version of Jelly Bean) will support the Miracast wireless display standard, and by default will have integrated features for it.[6] As of January 8, 2013, the Nexus 4, Sony Xperia Z, ZL, T and V officially support the function.[7][8] Miracast allows a portable device or computer to securely send up to 1080p HD video and 5.1 surround sound (AAC and AC3 are optional codecs, mandated codec is LPCM — 16 bits 48 kHz 2 channels)[9] to a compatible display wirelessly. It enables delivery of compressed standard or high-definition video over a wireless or wired network connecting any supported video source, (which would be computers, mobile phones, tablets, etc.) to any compatible display devices.[10] [edit]Screencasting Main article: Screencast Miracast is a form of screencast, and basically a real-time digital video screen capture of computer screen output, but instead of recording the video screen capture to disk it instead streams the video capture to a remote device with a screen, such as a television. The term screencast compares with the related term screenshot; whereas screenshot is a picture of a computer screen, a screencast is essentially a movie of the changes over time that a user sees on a computer screen, enhanced with audio narration. [edit]Devices The Wi-Fi Alliances maintains a current list of Miracast Certified devices. The technology and certification is fairly new with the first devices being certified September 2012. As of January 19th 2013, only just over 100 devices in total were certified. Nvidia announced support for it in their Tegra 3 platform,[11] and Texas Instruments, Qualcomm, Marvell Technology Group and other chip vendors have also announced their plans to support it.[12] Support for Miracast was added to Android in version 4.2 on October 29, 2012. Both devices (the sender and the receiver) need to be Miracast certified for the technology to work. However, to stream music and movies to a non-certified device there will be Miracast adapters available that plug into HDMI or USB ports.[13] [edit]Advantages Miracast is expected to be an industry-wide solution if it becomes widespread. The technology is expected to work well across devices, regardless of brand. Miracast devices automatically negotiate the settings they will use for a connection, which simplifies the process for the users. [edit]Ease of use Miracast is expected to perform the “nerdy grunt work behind the scenes”, obviating users having to “worry about format or codec”.[14] Miracast is “effectively a wireless HDMI cable, copying everything from one screen to another using the H.264 codec and its own digital rights management (DRM) layer emulating the HDMI system”. The Wi-Fi Alliance suggests that Miracast could also be used by a set-top box wanting to stream content to a TV, or tablet. [edit]Types of media streamed Miracast can stream videos that are in 1080p, media with DRM such as DVDs, as well as protected premium content streaming, enabling devices to stream feature films and other copy-protected materials. This is accomplished by using a Wi-Fi version of the same trusted content mechanisms used on cable-based HDMI and DisplayPort connections.[15] [edit]Disadvantages Miracast is limited to Wi-Fi Direct supported devices. Comparing to other IP-based screen mirroring applications such as Splashtop,[16] MirrorOp,[17] VNC and RDP, Miracast can not run on all IP networks such as conventional Wi-Fi, wired Ethernet, HomePlug Powerline networking and Internet, but those IP-based screen mirroring applications can run on Wi-Fi Direct. The Miracast standard also has “optional components” such as TLDI and WMM. The use of optional components in “standards” often causes issues if one vendor supports the options components and another does not. Its reliance on Wi-Fi Direct also reduces the attractiveness of the technology in enterprise environment. [edit]Legacy device incompatibility The Wi-Fi Alliance certified the Wi-Fi Direct protocol in October 2010, and the first smartphone to ship with Wi-Fi Direct was the Samsung Galaxy S II, released in February 2011. All new Android devices starting with Android 4.0x (Ice Cream Sandwich) support Wi-Fi Direct. PC hardware can be upgraded with new WiFi-Direct-compatible hardware. Only embedded devices will not be able to be upgraded. [edit]OS support At present time, Miracast Source is mainly active on Android platforms. Microsoft does not natively support Miracast in the new released Windows 8 and RT, but Windows software developers can implement Miracast easily, as Wi-Fi Direct is present as of Windows 7.[18] Apple supports its own AirPlay Mirroring instead of Miracast with the extra support of AirPlay Direct in next several months.[citation needed] [edit]Business Industry analysts predict annual shipments of Miracast-certified devices to exceed one billion units within the next four years.[19]