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Miracast

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Miracast is a peer-to-peer wireless screencast standard formed via Wi-Fi Direct connections in a manner similar to Bluetooth. It enables wireless or wired delivery of compressed standard or high-definition video to or from desktops, tablets, mobile phones, etc. Both the sending and receiving devices must 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.[10][1] 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).[2] However, it works only over Wi-Fi and cannot be used to stream to a router access point.[3][4][5][6][7] It was created by the Wi-Fi Alliance and billed as an open alternative to Apple's AirPlay Mirroring. It allows users to, for example, echo display from a phone or tablet 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.

Screencasting

Main article: Screencast

Miracast is a form of screencast, which is essentially a real-time digital video screen capture of computer screen output. But, instead of recording the video screen capture to local storage, it streams the video capture over a network to a remote device which has an attached 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.

Devices

The Wi-Fi Alliance maintains a current list of Miracast-certified devices, both source devices and display devices. The technology and certification is fairly new with the first devices being certified in September 2012. As of January 19, 2013, only just over 100 devices in total were certified.

Nvidia announced support for it in their Tegra 3 platform,[8] and Freescale Semiconductor, Texas Instruments, Qualcomm, Marvell Technology Group and other chip vendors have also announced their plans to support it.[9] 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.[10]

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.[11] As of January 8, 2013, the LG Nexus 4 and Sony's Xperia Z, ZL, T and V officially support the function,[12][13] as does HTC One and Samsung in its Galaxy S III and Galaxy Note II under the moniker AllShare Cast. The Galaxy S4 uses Samsung Link for its implementation.[14]

Microsoft also added support for Miracast in Windows 8.1, and announced this in June 2013. This functionality first became available in the Windows 8.1 Preview, and is available on hardware with supported Miracast drivers from hardware (GPU) manufacturers such as those listed above.

Failure of Miracast

As of 2013, Miracast has largely failed, due to lack of interoperability between certified devices. The bad experience of users who purchase certified devices and find that they don't work with other certified devices has been explored in the German IT magazine c't. They found that Miracast has tons of problems, including severe lag, bad compression and unreliable network connections.

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.

Ease of use

Miracast is expected to perform the "nerdy grunt work behind the scenes", obviating users having to "worry about format or codec".[15] 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.

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.[16]

Disadvantages

Miracast is limited to Wi-Fi Direct supported devices. Comparing to other IP-based screen mirroring applications such as Splashtop,[17] MirrorOp,[18] 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 Wireless Multimedia Extensions (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.

Latency

Certification does not mandate a maximum latency (i.e. the time between display of picture on the source and display of the mirrored image on the sink display).

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 Wi-Fi-Direct-compatible hardware. Only embedded devices will not be able to be upgraded.

OS support

At present time, Miracast Source is mainly active on Android platforms. Microsoft natively support Miracast in the upcoming update of Windows 8 and RT (called Windows 8.1), and Windows software developers can implement Miracast, as Wi-Fi Direct is present as of Windows 7.[19] Another way to support Miracast in Windows 7 is Intel WiDi v3.5 or above. With Intel WiDi v3.5 or above installed, Miracast can be supported. Apple supports its own AirPlay mirroring instead of Miracast on OS X. Blackberry 10.2 is rumored to have support for Miracast when it is released as well.

Business

Industry analysts, such as IHS iSuppli Research, predict annual shipments of Miracast-certified devices to exceed one billion units by 2016.[20]

Competitors

See also

References

  1. ^ http://www.anandtech.com/show/6116/nvidia-announces-compatibility-with-wifi-display-miracast-specification
  2. ^ https://www.wi-fi.org/sites/default/files/uploads/wp_Miracast_Industry_20120919.pdf
  3. ^ http://www.engadget.com/2012/07/26/nvidia-throws-support-behind-miracast/
  4. ^ http://gigaom.com/mobile/with-miracast-nvidias-tegra-3-enables-wireless-displays/
  5. ^ http://www.forbes.com/sites/greatspeculations/2012/06/15/windows-rt-compatibility-miracast-certification-to-enhance-tis-connectivity-solutions/
  6. ^ http://arstechnica.com/information-technology/2012/07/airplay-for-all-miracast-promises-video-streaming-without-the-router/
  7. ^ http://www.theverge.com/2012/10/29/3569244/android-4-2-new-features-miracast-gesture-keyboard-multiple-users-photo-sphere/in/3335719
  8. ^ "Nvidia supports Miracast".
  9. ^ "Airplay for all?".
  10. ^ Chacos, Brad (21 September 2012). "How Miracast Could Finally Make Your Smartphone Run Your Home Theater". Digital Trends.
  11. ^ http://androidandme.com/2012/10/news/android-4-2-adds-official-support-for-miracast-wireless-display/ Android 4.2 adds official support for Miracast wireless display
  12. ^ http://phandroid.com/2012/11/19/psa-nexus-7-and-nexus-10-do-not-support-miracast-wireless-display/
  13. ^ http://www.xperiablog.net/2012/12/03/wi-fi-miracast-screen-mirroring-demoed-on-the-xperia-t-video/
  14. ^ http://www.sammobile.com/2013/03/27/trying-samsungs-renewd-application-samsung-link/
  15. ^ Wagner, Kyle (19 September 2012). "What Is Miracast?". Gizmodo.
  16. ^ Parrish, Kevin (19 September 2012). "Wi-Fi Alliance Announces First Miracast-Certified Devices". Tom's Hardware.
  17. ^ http://www.splashtop.com/
  18. ^ http://www.mirrorop.com/
  19. ^ http://msdn.microsoft.com/en-us/library/windows/hardware/jj124675.aspx
  20. ^ http://www.wi-fi.org/media/press-releases/easy-use-multi-vendor-wireless-display-has-arrived-wi-fi-alliance%C2%AE-launches-wi
  21. ^ http://www.dial-multiscreen.org/
  22. ^ http://nextmarket.quora.com/DIAL-vs-AirPlay-Miracast
  23. ^ http://www.forbes.com/sites/michaelwolf/2013/01/26/why-dial-netflix-googles-airplay-killer-is-not-a-killer-at-all/
  24. ^ http://www.theregister.co.uk/2013/01/28/dial_youtube_netflix/
  25. ^ http://androidheadlines.com/2012/10/why-miracast-might-be-a-better-way-to-go-than-dlna-in-android-4-2.html
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